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Research ArticleMobile Coverage in Rural Sweden Analysis of a ComparativeMeasurement Campaign
P G Sudheesh 1 and Jaap van de Beek 2
1Department of Electronics and Communication Manipal Institute of Technology MAHE Udupi India2Department of Computer Science Electrical and Space Engineering Lulea University of Technology Lulea Sweden
Correspondence should be addressed to P G Sudheesh pgsudheeshgmailcom
Received 9 September 2020 Revised 6 November 2020 Accepted 10 December 2020 Published 5 January 2021
Academic Editor Peter Brida
Copyright copy 2021 P G Sudheesh and Jaap van de Beek is is an open access article distributed under the Creative CommonsAttribution License which permits unrestricted use distribution and reproduction in anymedium provided the original work isproperly cited
Under the umbrella of 1G to 5G different technologies have been used to provide mobile communication Various technologiesare being proposed to bring a person in remote area under coverage However a statistical analysis on what these users get fromalready existing technologies has not been carried out We fill this gap by carrying out such a study using a measurementcampaign where we present a framework for analyzing mobile signal strength experienced at the user end Measurements aretaken throughout the Norrbotten county the northernmost county in Sweden usingmobile phones recording various parametersat regular intervals Based on measured signal strength a coverage map has been made via inverse distance weighting (IDW)interpolation Based on the coverage map various analyses are carried out on signal strength over residential areas and roads ofNorrbotten Overall we lay a framework to analyze and quantify the effect of signal strength on users
1 Introduction
Earlier this year 3rd Generation Partnership Project (3GPP)released the first versions of its 5G new radio (NR) standardfirst as a non-stand-alone mode and later the stand-alonemode For a while now it has become clear that this standardessentially has its focus on the urban areas Use cases andscenarios invariably address dense network environmentssmall cells and a large number of mobile users per unit area
Naturally concerns have been raised by stakeholdersrepresenting rural values needs and interests With ever-decreasing cell sizes how will areal coverage be guaranteed isbased not only on the old standards and systems but also onnew essential 5G functionalities as network slicing ultralowlatencies and massive bandwidth [1]
e first 5G testbed in Norrbotten Sweden was tested inJune 2019 [2] and therefore for majority of population 5Gnetwork is still not accessible Also 5G handsets are also notso widely available in the market Hence a major portion ofthe population is still using 2G 3G andor 4G network formobile communication erefore expanding coverage area
and bringing more people under mobile coverage map re-quire network planning and installing new base stations
However installing terrestrial base stations (BS) andproviding backhaul are subject to the revenue earned fromthe mobile users [3] erefore installing a terrestrial basestation and associated backhaul in ldquonot so popularrdquo areas isnot attractive from an economical point of viewis in turnresults in deployment of lesser number of base stations oreven absence of base stations in such sparsely populatedareas
As a result the people in these areas are subjected to pooror absence of coverage It is widely known that larger op-erators and stakeholders of telecom industry do not want toput up new base stations in nonprofitable areas In otherwords the telecom companies hold the right not to put upnew base stations in places that are not profitable to them[4] It is rather interesting that the notion of full coverage islimited only to the areas defined by the operators
To overcome these limitations and provide full coverageirrespective of population density different solutions likepositioning UAV BS [5] and new allocation spectrum [6] are
HindawiMobile Information SystemsVolume 2021 Article ID 8869534 13 pageshttpsdoiorg10115520218869534
considered Swedish regulators have come up with new700MHz band that focuses on lesser coverage areas [6] Tothis end Swedish authorities and especially Norrbotten thenorthernmost county in Sweden wanted to identify andfocus on the areas with no or poor coverage [4] Neither thecoverage map from operators nor the location of base sta-tions was available to researchers To this end we generate acoverage map generated using crowd sourced measurementsacross Norrbotten
It is found in [7] that mobile coverage is directly linked tosocioeconomic performance erefore in this paper wemeasure the coverage poverty experienced by the peopleSeveral attempts have been done to calculate areas withoutcoverage [8 9] Effect of mobile coverage on railway networkin Norway is studied in [10] ese attempts however donot really give an idea of quality of service experienced by theusers erefore to quantify the quality of service thecoverage poverty experienced by (a) people living in theirapartments and (b) cars plying through the roads ofNorrbotten province of Sweden is mathematicallycalculated
e paper is organized as follows A review of techniquesused to analyze effect of signal strength in various conditionsis provided in Section 2 A detailed explanation of generatingcoverage map from crowd sourced measurements is pro-vided in Section 3 Section 4 is devoted to result analysiswhile conclusions are listed in Section 5
2 Coverage Maps from Scattered Samples
In this section we elaborate the methods by which the signalstrength over the populated areas and roads are analyzedusing measured signal strengths ere are different ways ofgenerating a coverage map and analyzing the signal strength(1) identifying BS and then calculating the signal strengthusing factors such as path loss [11] (2) finding base stationlocation frommanually measured signal strength at differentlocations [12ndash14] and (3) generating coverage map frommanually measured signal strength values Since the loca-tions of BS are not disclosed to public we resort to the thirdmethod where we use tens of millions of measurements togenerate coverage map With millions of measurements it ismore likely to get a predicted signal strength than resortingto earlier methods e signal strength measurements aretaken for different operators and radio access technology(RAT) at difference time instances which are then inter-polated to form rectangular zones depicting average signalstrength over that area However as we are only relying onavailable signal strength to generate coverage map we misslot of area as unmapped region
21 Generating Coverage Map e availability of mea-surements is limited to GPS coordinates on roads in generalis is because measurements are usually carried out bymobiles that are kept in the vehicles erefore practically itis impossible to measure signal strength throughout the areato be mapped and identify exact signal strength at thoselocations erefore we use the signal strength from the
available signal strength measurements to calculate signalstrength in the rest of the areas
In order to generate coverage map of various RATs andoperators it is important to separate the measured signalse measurement from mobile phones contains networktype info operator and signal strength based on which it ispossible to filter the point to corresponding sets that rep-resent different RATs and operators erefore for eachoperator sets of different RATs such as SLTE SUMTS SGSMcan be made Sets SLTE SUMTS and SGSM represent the sets ofmeasurements under LTE UMTS and GSM respectivelye subscripts to S represent different RATs
Interpolation techniques such as kriging and inverse dis-tance weighting [15] are widely used for obtaining coveragearea map using measured signal strengths Although differentversions of kriging such as ordinary kriging and universalkriging are popular for crowd sourced measurements acomputationally less complex algorithm is used here as weconsider large geographical area In [16 17] the authorscompare kriging with IDW algorithm and find that krigingprovides slightly better results compared to IDW However itis mentioned in [17] that the computational complexity forkriging is much higher which is not a great concern when thearea under study is small But as the area under study is largecomputationally simple IDW algorithm is preferred overkriging to generate coverage maps for all operators and RATs
IDW algorithm predicts the signal strength in locationswhere measured points are not available IDW algorithmmakes use of the fact that measurements in the near vicinitycontribute better than farther pointserefore bigger numberof measured signal strength makes the signal strength pre-diction more closer to a possible real measurement It is in-teresting to note that the IDW algorithm produces anaveraging effect on measurements that are isolated Howeverin case of crowded measurements the signal strength assignedto the polygon is affected not only by the measurements in itbut also by the measurements near to it
e output of IDW algorithm is a raster map made up ofa grid of pointsese points are located at the center of eachpixel which is the basic building block of the raster Togenerate a coverage map a signal strength value is assignedto each point in the grid based on the available signalstrength values e points in grid and measured point aremarked as blue and red dots respectively in Figure 1 Al-though the IDW algorithm does not limit the number ofpoints that are used in order to calculate the signal strengthof point in the grid since the points in the vicinity contributemore to the measurement we restrict the search to a circlewhere each point in the grid is the center of the search circle
e points in the grid are spaced at distance d which isalso the length of the edge of each raster (coverage map) cellUsing Toblerrsquos rule [18] the grid spacing d is taken as
d map scale2 times 1000
(1)
where map scale depends on where the points under studyare spread In effect the length of edges of raster is de-pendent on the distance of right-most left-most top-mostand bottom-most points among the available points
2 Mobile Information Systems
To generate the raster each pixel or spatial object musthold the value of an element from a set M erefore anobject O must have two properties
(a) A spatial extent Zi
(b) A function fO that assigns a value from setM to eachpoint in Zi
Considering the search radius r object O is defined as
O Zi MiΨr( 1113857 (2)
us object O is a tuple (Zi MiΨr) where Mi isin M andZi subeR2 e function fO Zi⟶ M whereM R ldquoNO SIGNALrdquo In effect the value fO(xi yi) re-flects the signal strength to be attributed to (xi yi) isin Zi edistance d between neighbouring points in a raster (xi yi)is obtained from equation (1) e signal strength Mi foreach point in raster at location (xi yi) is given as
Mi 1113936
xjyj( 1113857isinSSj xi minus xj1113872 1113873
2+ yi minus yj1113872 1113873
21113874 1113875
minus αΨr xj yj1113872 1113873
1113936xjyj( 1113857isinS
xi minus xj1113872 11138732
+ yi minus yj1113872 11138732
1113874 1113875minusα (3)
Ψr xj yj1113872 1113873fO xj yj1113872 1113873 fO xj yj1113872 1113873 if
xi minus xj1113872 11138732
+ yi minus yj1113872 11138732
1113969
lt r
0 if
x0 minus xj1113872 11138732
+ y0 minus yj1113872 11138732
1113969
gt r
⎧⎪⎪⎨
⎪⎪⎩(4)
where Sj isin S S R ldquoNO SIGNALrdquo and dij is theEuclidean distance between measured point j and point i inthe grid α denotes the distance exponent or power indexwhich is taken as 2 e characteristic function Ψr is definedas in equation (4) where r is the search radius Hence aftersuccessful implementation of (3) on SLTE SUMTS and SGSMwe get MLTE MUMTS and MGSM representing the coveragemap for LTE UMTS and GSM respectively
22 Coverage Specific Aspects To generate coverage map ofTelia Tele2 and Telenor for each LTE UMTS andGSM IDWalgorithm must be carried out to each ensemble of measure-ments dedicated to each of the above operators and RATs eIDW applied to each of these groups of measurements isexplained in Section 21 A simple IDW with all the mea-surements where rdquoNO SIGNALrdquo is also an entry will generatewrong results and therefore needs to be treated separately
d
(xi yi)
Points withmeasurement
r
Points in grid
Figure 1 Selecting points to run IDW algorithm
Mobile Information Systems 3
Here we formulate a coverage specific approach to gen-erate coverage map by taking into account both real signalmeasurements and points with no signal measurements ealgorithm is represented in Figure 2e first step is to separatepoints with valid signal measurements and points withoutsignal strengths and generate coverage map for each set eserasters or grids of points are then converted to polygons Nowthe difference between coveragemaps with validmeasurementsand no signal strengths is createdis output is thenmerged tothe coverage map with valid measurements
It is still possible to have polygons with more pointswithout signal strength and less points with valid mea-surements To address such situations a final step is re-quired at is the polygon is assigned rdquoNO SIGNALrdquowhen the number of points without valid measurements ismore even if there is a valid signal strength assigned to it Inthe absence of such situations the signal strength valueassigned to the final coverage polygon remains the same asthe one from the coverage map generated from validmeasurements
3 Practical Case Study
31 Measurements In order to generate raster we measurethe signal strengths of various operators and RATs with GPScoordinates and time stamps e measurement is made byusing set of mobile phones which are locked to specificoperators and RATse set of mobile phones is kept in a bagas shown in Figure 3 where each phone is locked to a singleoperator and RAT To this end three operators in Sweden arecompared where Tele2 and Telenor share the same infra-structure for 2G (GSM) and 4G (LTE) erefore each bagcontains 2 phones to measure 2G signal and 3 phones tomeasure 3G signal and again 2 phones to measure 4G signalwhich records measurements at regular intervals
We consider three operators Telia Tele2 and Telenorover the Norrbotten region which is the northernmostprovince in Sweden e mobile phones that measure signalstrengths are enclosed in a bag and are placed in vehicles andboats plying through the area under studyemobile phonescollect data namely GPS coordinates date time networktype signal strength operator cell identification code (CID)location area code (LAC) and eNode bid at regular intervalsIt is worth noting that themeasurements from various phonesin the bag are not time-synchronized
e two GSM phones measure broadcast channel (BCCH)and the signal strength measured in GSM is the received signalstrength indicator (RSSI) e 3G RAT used in the phones isuniversal mobile telecommunications system (UMTS) whichis a wideband code divisionmultiple access (WCDMA) systemerefore the mobile phones dedicated to measuring 3Gsignals measure the received power on one code over theprimary common pilot channel (CPICH)is value is referredto as the received signal code power (RSCP) e 4G RAT isalso known as the long-term evolution (LTE) standard whichuses time-frequency resource block with varying channel size(from 14 to 20MHz) erefore the useful power is con-tributed by different resource blocks which is measured asreference signal received power (RSRP)
e 2G and 3G phones are locked to 2G and 3G RATrespectively is means that the mobile phone cannotperform handover operation from 3G to 2Gwhen it has poorsignal strength However the 4G mobile phones are notlocked to RATs and as a result they switch RATfrom LTE toUMTS and then fromUMTS to GSM based on the measuredsignal strength In other words the phones that measureLTE signals provide RSRP values in fewer areas even thoughthere are RSRP values when phone switches to other RATsfrom LTE
e number of measurements received per munici-pality is given in Table 1 In this paper we study thedistribution of signal strength over residential areas androads e population and road lengths associated witheach of the municipalities are listed in the table enumber of measurements per municipality consists of threeRATs and three operators e population map consideredfor analysis is a 1 km times 1 km polygon shape file provided by[19] e road data is given by [20] which provides in-formation about number of vehicles moving through thatparticular road
32 Framework to Analyze the Quality of Service With themeasurements in hand this section lays the framework toanalyze the distribution of signal strength over residentialareas and roads For this purpose we use two sets of polygonfiles population and road as a base layer that extracts signalstrength from the superimposed coverage map While thefirst helps us to study the effect in static users the latterprovides insight into the coverage for mobile users Furtherwe define different levels from LTE UMTS and GSM signalstrength with which the quality of service enjoyed by theusers can be easily identified e algorithm used for clas-sification of user levels is mentioned in Figure 4e fact thatLTE UMTS and GSM offer better service in the respectiveorder is used for forming the algorithm While RSRPgtminus80 dBm is an excellent signal strength in LTEminus90 dBm lt RSRP lt minus80 dBm offers poorer performancethan the former [21]erefore we assign the former as level1 and the latter as level 2 Following the pattern we assignhigher levels to the LTE and lower levels to UMTS [21] as thedata rate decreases in UMTS compared to LTE is patternis repeated in GSM as well [22]
Note that the points labelled No Signal and NULL arenot considered while assigning levels till level 12 whereNo Signal represents a situation where UEs did not receiveany signal whereas NULL considers a scenario wherepolygon does not have a signal strength to map to Level 13 isused to represent the signal strength that is lesser than theminimum required signal strength for a reliable commu-nication A scenario where the UE cannot make call in any ofthe RAT is considered in level 14 e difference betweenlevel 13 and level 14 is that connection is not possible in level14 while connection may be possible with possible chance ofdisconnection in level 13 [21 23] For example if the deviceunder test has LTE signal strength below minus100 dBm UMTSsignal strength below minus85 dBm and GSM signal strengthbelow minus110 dBm the signal strength values in mobile
4 Mobile Information Systems
phones fall below the minimum recommended signalstrength [21 23] Such a situation is possible in level 13Meanwhile if all devices are not getting any signal from thebase station we assign level 14 which is the worst situationamong all Level 15 does not represent the quality of thesignal as it houses the regions where the measurementcampaign was not performed
321 Framework to Analyze Effects in Residential AreasIn this subsection we study the effect of signal strength onusers in residential areas Figure 5 demonstrates the ex-traction of signal strength from the coverage mape upperlayer is the coverage map which holds the signal strengthvalue e lower layer which is population map in thiscontest extracts signal strength from the overlapping cov-erage map and adds the signal strength value Mk to eachpolygon of the population or road map
In order to extract Mk from an overlapping coveragemap each polygon uses the settings in Table 2 which isexecuted using QGIS a free geographic information
Figure 3 Measurement setup by IQMTEL Sweden
Go to polygon 1
Do nothing
No
Yes
Unprocessedpolygon
No
Points withvalid signal
strength
Pointswithout signal
strength
Inputmeasurements
(points)
Separate points with andwithout signal strengths
Run IDWalgorithm
Run IDWalgorithm
Combine thecoverage maps by
UNION
Outputcoverage map
CNoSig = count of points without measurement in polygonCM = count of points with measurement in polygon
Yes
Assign signal strength ofoutput polygon to
ldquoNO_SIGNALrdquo
If CNoSiggtCM
Figure 2 Algorithm to generate coverage map
Table 1 Measurements across municipalities of Norrbotten
SIno Municipality No of
measurementsArea(km2) Population Road
(km)1 Alvsbyn 708191 17904 8256 53012 Arjeplog 887558 144983 2903 72013 Arvidsjaur 1826754 60857 6490 101994 Boden 2409219 42771 28373 87595 Haparanda 378870 168067 9851 28466 Jokkmokk 2089506 9332 5132 79637 Kalix 940068 193144 16240 65278 Lulea 4603223 18503 78160 7679 Pajala 1821622 206423 6157 1004510 Pitea 3883938 21558 41932 919611 Gallivare 3070680 29139 18023 976612 Kiruna 2315800 25157 23233 730113 Overkalix 325123 81037 3409 521714 Overtornea 671210 32461 4582 5561
Mobile Information Systems 5
system (GIS) software at is the polygon in populationor road map considers those signal strengths from theoverlapping coverage map when the polygon in coveragemap intersects with it In case the population or road mappolygon intersects with multiple polygons of the cov-erage map the algorithm selects one random valueamong them thereby creating a one-to-one mappingwith each polygon in population or road map and signalstrength value
322 Framework to Analyze Effects in Roads Since theroads can stretch to few kilometers and assigning signalstrength to each line is impossible we split the linesrepresenting roads to segments of 100m or less for ab-sorbing information from overlapping coverage map Forexample a road whose length is 1050 km is divided into10 units each of 100m and one unit of length 50m econtribution of the unit of length x where xlt 100m istaken as x100 while calculating total number of segments
Level 3
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SLTE lt ndash90dBm
Level 4
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SUMTS gt ndash60dBm
Level 15
SLTE isin ldquoNULLrdquo ANDSUMTS isin ldquoNULLrdquo AND
SGSM isin ldquoNULLrdquo
Level 10
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SLTE lt ndash100dBm
Level 9
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SGSM lt ndash85dBm
Level 2
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash90dBm lt SLTE lt ndash80dBm
Level 5
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash75dBm lt SUMTS lt ndash60dBm
Level 14
SLTE isin ldquoNo Signalrdquo ANDSUMTS isin ldquoNo Signalrdquo AND
SGSM isin ldquoNo Signalrdquo
Level 11
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash95dBm lt SUMTS lt ndash85dBm
Level 8
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SGSM lt ndash70dBm
Level 1
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SLTE gt ndash80dBm
Level 6
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SUMTS lt ndash75dBm
Level 13
SLTE notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSLTE lt ndash100dBm AND
SUMTS notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSUMTS lt ndash85dBm AND
SGSM notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSGSM lt ndash110dBm AND
Level 12
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SGSM lt ndash100dBm
Level 7
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SGSM gt ndash70dBm
Figure 4 Assigning signal levels
Coverage map
Polygon (population road map)Mk
Zk
Figure 5 Extracting signal strength from coverage map
6 Mobile Information Systems
in a particular level Signal strength value is extractedfrom overlapping coverage map of each RAT SLTE SUMTSand SGSM and is assigned to each line segment As a resultin addition to signal strength value the line segmentobject also carries the length of each segment e linesegment extracts signal strength value from overlappedcoverage map (M) with the settings shown in Table 2 As aresult each line segment object q is a tuple (Zq Mq lq)where lq is the length of the line segment q
Furthermore to analyze the performance of variousoperators to users on road we define two variables λq andϕq e basic logic here is that the coverage poverty expe-rienced by 100 cars in 1 km is the same as that of 1 car in100 km erefore to quantify the coverage poverty wemultiply the number of cars moving through segment q withlq Also to incorporate smaller road segments we normalizethe product by length erefore we define λ for segment q
λq number of cars through q times lq
100 (5)
Since different roads have speed limits we must add thisfactor into consideration as the vehicle stays on road formore time in poor coverage areas erefore we defineanother parameter
ϕq λq times 3600
1000 (6)
where the numerator specifies the speed in (kmhr) and toconvert it to (ms) and we multiply the term by 36 esetwo variables quantify the coverage poverty of absence ofcoverage to the users
4 Data Analysis
41 Signal Strength across Residential Areas inMunicipalitiesHistogram of signal strength is analyzed for various RATsand operators For the ease of comparison we consider LTEby Telia in Lulea and Pajala a comparatively densely pop-ulated municipality and a sparsely populated municipalityrespectively Further the histogram of GSM signal strengthis plotted and compared with that of LTE
Figure 6 shows histogram of GSM signal strength wherethe height of each bar shows the percentage of people fallingin the respective slot Both municipalities have maximumnumber of people in minus70 dBm to minus60 dBm range for GSMAlso the range is the same for most of the municipalities
From Figure 7 we can see that the behaviour in LTE issimilar to that of GSM but majority of people fall inminus100 dBm to minus90 dBm range Most of the municipalitiesshow similar behaviour It is visible that there is a shift inmostly used signal strength in GSM and LTE at is fromFigure 4 it is known that minus70 dBm to minus60 dBm range in RSSI
is an excellent GSM signal strength and minus100 dBm tominus90 dBm LTE signal strength offers only fair service to theusers On the contrary the quality of service offered by LTEfor signal strength from minus100 dBm to minus90 dBm is still betterthan GSM signal strength of minus70 dBm to minus60 dBm
42 Signal Strength across Roads in MunicipalitiesFigure 8 shows the histogram of signal strength for TeliaGSM For fair comparison of histograms generated forresidential areas we consider the same municipalitiesLulea and Pajala Unlike residential areas where bothmunicipalities have maximum number of people inminus70 dBm to minus60 dBm range for GSM roads of thesemunicipalities have maximum number of people inminus90 dBm to minus80 dBm and minus80 dBm to minus70 dBm rangesrespectively It is observed that this shift is common formost of the municipalities Another interesting obser-vation is that the sparsely populated municipality Pajalahas better signal strength in most of its roads despite thelow population density
e LTE signal strength in roads of Pajala is reported inFigure 9 Compared to Figure 8 a decrease in signal strengthis observed Although there is a dip in average signal strengthin LTE the performance at the user end is still better thanthat of GSM Unlike the histograms of residential areaswhere the absence of measurement (ldquoNo Datardquo) is almostzero the percentage of roads without measurement is biggeris is mainly due to the mode of measurement where themeasurements are taken by phones placed in mostly publicutility vehicles
43 Effect of Traffic Pattern In this subsection we quantifythe effect of 3G signal strength on users on roadsFigure 10(a) plots histogram of λ where λ λq1113966 1113967 for various3G operators in Jokkmokk With this approach the bestoperator can be identified Similarly Figure 10(b) plotshistogram of ϕ where ϕ ϕq1113966 1113967 for various 3G operators inJokkmokk While the latter gives the idea about temporalsignal quality experienced by an average user in car theformer shows the number of cars experiencing the signalstrength However both figures have more or less the samepattern
44 Quantifying the Coverage Poverty It is quite clear thatdifferent municipalities get affected in different levels A lowsignal strength in highly populated municipality will havehuge impact compared to a less populated area Figure 11analyzes average GSM signal strength of Telia on totalpopulation of municipalities While the position of circlesrepresents themean signal strength and percentage of peoplewithout service the radius of the circles in scatter plot shows
Table 2 Feature extraction
SI no Option Setting in algorithm1 Geometric predicate Intersect2 Mapping (join type) One-to-one3 Fields to add Signal strength
Mobile Information Systems 7
the population or total road length in respective munici-palities Figure 11(a) reports the percentage of populationwithout signal versus mean signal strength with GSM It is
clear that most of the users in residential areas enjoy fair-quality GSM signal Most of the populated municipalitieshave decent signal quality Also a very small percentage (less
002 0 0 0 004 208
25362812
3999
3940 0450
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
Dat
a
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 188
1117
2877
5455
285 0 0770
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 6 GSM coverage in residential areas (a) Coverage in residential areas of Lulea (b) 2G Coverage in residential areas of Pajala
0 0 005 342
2592
5237
1282 526
0 0 0 0160
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 02 215
1411
4055
18962333
0 0 0 070
25
50
of p
opul
atio
n
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 7 LTE coverage in residential areas (a) 4G coverage in residential areas of Lulea (b) 4G Coverage in residential areas of Pajala
072 0 0 0 213
1838
3635
2649
854 106 0
634
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 599
2526
3426
2127
276 0
1047
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 8 GSM coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
8 Mobile Information Systems
than 15) of residential area is not covered However onanalyzing signal strength on roads in Figure 11(b) a declinein signal strength is observed Although majority of mu-nicipalities get most of their roads under coverage area thereare municipalities like Overtornea where considerablefractions of roads are not covered
45 Signal Strength inUrban Suburban andRest of theArease effect of signal strength to users in residential areas inurban suburban and rest of the areas is reported in Fig-ure 12e term rest of the areas is used to denote residentialareas that do not fall under urban or suburban category eCDF of population is plotted against GSM signal strengthWhile GSM offers best signal strength in urban areas themedium and least signal strengths are observed in suburban
areas and rest of the areas respectively A fraction ofpopulation is under no coverage area of Tele2 and Telenor insuburban areas and rest of the areas However despite theregion classification Telia offers 1ndash4 dB better signal tousers It is also important to note that the results in Figure 12are based only on the available data We have not consideredareas without measurements for analysis
46 ComparisonwithAnother County GSM signal strengthsof two different counties in Sweden Norrbotten andOstergotland are compared in Figure 13 We compare thesignal strengths observed in urban and suburban areas ofboth counties From Figure 13(a) it is clear that despite ofthe county the signal strength in urban areas remains thesame However from 13(b) it can be observed that the user
02 0 276
1711
3728
2718
753051 0 0 0
743
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(a)
0 0 078
89
26813121
1816
3530 0 0
106
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(b)
Figure 9 LTE coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
Telia
0 0 1411131
3518 3448
1152025 009 0
5750
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
Tele2
0
3268
1631 152058
531 436 0 0 0576
0
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Telenor
01032 1448
24813089
867 5080 0 0
5760
25
C
arstimes
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
ndash140
ndash ndash
130
Signal strength (dBm)
(a)
Telia
0 0 1321196
3713 3348
991027 01 0 583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Tele2
0
3458
1722 155 1947
498 242 0 0 0583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0Telenor
01069 152
24863132
896314 0 0 0
5830
25
C
ars times
s
ndash60
ndash ndash5
0
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash90
ndash ndash8
0
ndash140
ndash ndash
130
Signal strength (dBm)
(b)
Figure 10 Effect of traffic pattern (a) Carstimes 100m (b) Carstimes sec
Mobile Information Systems 9
ARJEPLOG
ARVIDSJAUR
BODEN
GAumlLLIVARE
HAPARANDA
JOKKMOKKKALIX
KIRUNALULEAring PAJALA
PITEAringAumlLVSBYNOumlVERKALIX
OumlVERTORNEAring
0
05
1
15
p
opul
atio
n w
ith n
o sig
nal
ndash75 ndash74 ndash73 ndash72 ndash71 ndash70ndash76Mean signal strength (dBm)
(a)
ARJEPLOG
ARVIDSJAURGAumlLLIVARE
HAPARANDA JOKKMOKK
KALIX
KIRUNALULEAring
PAJALA
PITEAringAumlLVSBYN
OumlVERKALIX
OumlVERTORNEAring
0
1
2
3
4
5
6
7
ro
ad w
ith n
o sig
nal
ndash84 ndash83 ndash82 ndash81 ndash80 ndash79 ndash78 ndash77 ndash76ndash85Mean signal strength (dBm)
BODEN
(b)
Figure 11 Impact on of roadspopulation in Telia (a) Residence area (b) Roads
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Suburban
Urban
Rest of thearea
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
0
02
04
06
08
1
CDF
of p
opul
atio
n
Figure 12 Signal strength in urban suburban and rest of the areas
10 Mobile Information Systems
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
considered Swedish regulators have come up with new700MHz band that focuses on lesser coverage areas [6] Tothis end Swedish authorities and especially Norrbotten thenorthernmost county in Sweden wanted to identify andfocus on the areas with no or poor coverage [4] Neither thecoverage map from operators nor the location of base sta-tions was available to researchers To this end we generate acoverage map generated using crowd sourced measurementsacross Norrbotten
It is found in [7] that mobile coverage is directly linked tosocioeconomic performance erefore in this paper wemeasure the coverage poverty experienced by the peopleSeveral attempts have been done to calculate areas withoutcoverage [8 9] Effect of mobile coverage on railway networkin Norway is studied in [10] ese attempts however donot really give an idea of quality of service experienced by theusers erefore to quantify the quality of service thecoverage poverty experienced by (a) people living in theirapartments and (b) cars plying through the roads ofNorrbotten province of Sweden is mathematicallycalculated
e paper is organized as follows A review of techniquesused to analyze effect of signal strength in various conditionsis provided in Section 2 A detailed explanation of generatingcoverage map from crowd sourced measurements is pro-vided in Section 3 Section 4 is devoted to result analysiswhile conclusions are listed in Section 5
2 Coverage Maps from Scattered Samples
In this section we elaborate the methods by which the signalstrength over the populated areas and roads are analyzedusing measured signal strengths ere are different ways ofgenerating a coverage map and analyzing the signal strength(1) identifying BS and then calculating the signal strengthusing factors such as path loss [11] (2) finding base stationlocation frommanually measured signal strength at differentlocations [12ndash14] and (3) generating coverage map frommanually measured signal strength values Since the loca-tions of BS are not disclosed to public we resort to the thirdmethod where we use tens of millions of measurements togenerate coverage map With millions of measurements it ismore likely to get a predicted signal strength than resortingto earlier methods e signal strength measurements aretaken for different operators and radio access technology(RAT) at difference time instances which are then inter-polated to form rectangular zones depicting average signalstrength over that area However as we are only relying onavailable signal strength to generate coverage map we misslot of area as unmapped region
21 Generating Coverage Map e availability of mea-surements is limited to GPS coordinates on roads in generalis is because measurements are usually carried out bymobiles that are kept in the vehicles erefore practically itis impossible to measure signal strength throughout the areato be mapped and identify exact signal strength at thoselocations erefore we use the signal strength from the
available signal strength measurements to calculate signalstrength in the rest of the areas
In order to generate coverage map of various RATs andoperators it is important to separate the measured signalse measurement from mobile phones contains networktype info operator and signal strength based on which it ispossible to filter the point to corresponding sets that rep-resent different RATs and operators erefore for eachoperator sets of different RATs such as SLTE SUMTS SGSMcan be made Sets SLTE SUMTS and SGSM represent the sets ofmeasurements under LTE UMTS and GSM respectivelye subscripts to S represent different RATs
Interpolation techniques such as kriging and inverse dis-tance weighting [15] are widely used for obtaining coveragearea map using measured signal strengths Although differentversions of kriging such as ordinary kriging and universalkriging are popular for crowd sourced measurements acomputationally less complex algorithm is used here as weconsider large geographical area In [16 17] the authorscompare kriging with IDW algorithm and find that krigingprovides slightly better results compared to IDW However itis mentioned in [17] that the computational complexity forkriging is much higher which is not a great concern when thearea under study is small But as the area under study is largecomputationally simple IDW algorithm is preferred overkriging to generate coverage maps for all operators and RATs
IDW algorithm predicts the signal strength in locationswhere measured points are not available IDW algorithmmakes use of the fact that measurements in the near vicinitycontribute better than farther pointserefore bigger numberof measured signal strength makes the signal strength pre-diction more closer to a possible real measurement It is in-teresting to note that the IDW algorithm produces anaveraging effect on measurements that are isolated Howeverin case of crowded measurements the signal strength assignedto the polygon is affected not only by the measurements in itbut also by the measurements near to it
e output of IDW algorithm is a raster map made up ofa grid of pointsese points are located at the center of eachpixel which is the basic building block of the raster Togenerate a coverage map a signal strength value is assignedto each point in the grid based on the available signalstrength values e points in grid and measured point aremarked as blue and red dots respectively in Figure 1 Al-though the IDW algorithm does not limit the number ofpoints that are used in order to calculate the signal strengthof point in the grid since the points in the vicinity contributemore to the measurement we restrict the search to a circlewhere each point in the grid is the center of the search circle
e points in the grid are spaced at distance d which isalso the length of the edge of each raster (coverage map) cellUsing Toblerrsquos rule [18] the grid spacing d is taken as
d map scale2 times 1000
(1)
where map scale depends on where the points under studyare spread In effect the length of edges of raster is de-pendent on the distance of right-most left-most top-mostand bottom-most points among the available points
2 Mobile Information Systems
To generate the raster each pixel or spatial object musthold the value of an element from a set M erefore anobject O must have two properties
(a) A spatial extent Zi
(b) A function fO that assigns a value from setM to eachpoint in Zi
Considering the search radius r object O is defined as
O Zi MiΨr( 1113857 (2)
us object O is a tuple (Zi MiΨr) where Mi isin M andZi subeR2 e function fO Zi⟶ M whereM R ldquoNO SIGNALrdquo In effect the value fO(xi yi) re-flects the signal strength to be attributed to (xi yi) isin Zi edistance d between neighbouring points in a raster (xi yi)is obtained from equation (1) e signal strength Mi foreach point in raster at location (xi yi) is given as
Mi 1113936
xjyj( 1113857isinSSj xi minus xj1113872 1113873
2+ yi minus yj1113872 1113873
21113874 1113875
minus αΨr xj yj1113872 1113873
1113936xjyj( 1113857isinS
xi minus xj1113872 11138732
+ yi minus yj1113872 11138732
1113874 1113875minusα (3)
Ψr xj yj1113872 1113873fO xj yj1113872 1113873 fO xj yj1113872 1113873 if
xi minus xj1113872 11138732
+ yi minus yj1113872 11138732
1113969
lt r
0 if
x0 minus xj1113872 11138732
+ y0 minus yj1113872 11138732
1113969
gt r
⎧⎪⎪⎨
⎪⎪⎩(4)
where Sj isin S S R ldquoNO SIGNALrdquo and dij is theEuclidean distance between measured point j and point i inthe grid α denotes the distance exponent or power indexwhich is taken as 2 e characteristic function Ψr is definedas in equation (4) where r is the search radius Hence aftersuccessful implementation of (3) on SLTE SUMTS and SGSMwe get MLTE MUMTS and MGSM representing the coveragemap for LTE UMTS and GSM respectively
22 Coverage Specific Aspects To generate coverage map ofTelia Tele2 and Telenor for each LTE UMTS andGSM IDWalgorithm must be carried out to each ensemble of measure-ments dedicated to each of the above operators and RATs eIDW applied to each of these groups of measurements isexplained in Section 21 A simple IDW with all the mea-surements where rdquoNO SIGNALrdquo is also an entry will generatewrong results and therefore needs to be treated separately
d
(xi yi)
Points withmeasurement
r
Points in grid
Figure 1 Selecting points to run IDW algorithm
Mobile Information Systems 3
Here we formulate a coverage specific approach to gen-erate coverage map by taking into account both real signalmeasurements and points with no signal measurements ealgorithm is represented in Figure 2e first step is to separatepoints with valid signal measurements and points withoutsignal strengths and generate coverage map for each set eserasters or grids of points are then converted to polygons Nowthe difference between coveragemaps with validmeasurementsand no signal strengths is createdis output is thenmerged tothe coverage map with valid measurements
It is still possible to have polygons with more pointswithout signal strength and less points with valid mea-surements To address such situations a final step is re-quired at is the polygon is assigned rdquoNO SIGNALrdquowhen the number of points without valid measurements ismore even if there is a valid signal strength assigned to it Inthe absence of such situations the signal strength valueassigned to the final coverage polygon remains the same asthe one from the coverage map generated from validmeasurements
3 Practical Case Study
31 Measurements In order to generate raster we measurethe signal strengths of various operators and RATs with GPScoordinates and time stamps e measurement is made byusing set of mobile phones which are locked to specificoperators and RATse set of mobile phones is kept in a bagas shown in Figure 3 where each phone is locked to a singleoperator and RAT To this end three operators in Sweden arecompared where Tele2 and Telenor share the same infra-structure for 2G (GSM) and 4G (LTE) erefore each bagcontains 2 phones to measure 2G signal and 3 phones tomeasure 3G signal and again 2 phones to measure 4G signalwhich records measurements at regular intervals
We consider three operators Telia Tele2 and Telenorover the Norrbotten region which is the northernmostprovince in Sweden e mobile phones that measure signalstrengths are enclosed in a bag and are placed in vehicles andboats plying through the area under studyemobile phonescollect data namely GPS coordinates date time networktype signal strength operator cell identification code (CID)location area code (LAC) and eNode bid at regular intervalsIt is worth noting that themeasurements from various phonesin the bag are not time-synchronized
e two GSM phones measure broadcast channel (BCCH)and the signal strength measured in GSM is the received signalstrength indicator (RSSI) e 3G RAT used in the phones isuniversal mobile telecommunications system (UMTS) whichis a wideband code divisionmultiple access (WCDMA) systemerefore the mobile phones dedicated to measuring 3Gsignals measure the received power on one code over theprimary common pilot channel (CPICH)is value is referredto as the received signal code power (RSCP) e 4G RAT isalso known as the long-term evolution (LTE) standard whichuses time-frequency resource block with varying channel size(from 14 to 20MHz) erefore the useful power is con-tributed by different resource blocks which is measured asreference signal received power (RSRP)
e 2G and 3G phones are locked to 2G and 3G RATrespectively is means that the mobile phone cannotperform handover operation from 3G to 2Gwhen it has poorsignal strength However the 4G mobile phones are notlocked to RATs and as a result they switch RATfrom LTE toUMTS and then fromUMTS to GSM based on the measuredsignal strength In other words the phones that measureLTE signals provide RSRP values in fewer areas even thoughthere are RSRP values when phone switches to other RATsfrom LTE
e number of measurements received per munici-pality is given in Table 1 In this paper we study thedistribution of signal strength over residential areas androads e population and road lengths associated witheach of the municipalities are listed in the table enumber of measurements per municipality consists of threeRATs and three operators e population map consideredfor analysis is a 1 km times 1 km polygon shape file provided by[19] e road data is given by [20] which provides in-formation about number of vehicles moving through thatparticular road
32 Framework to Analyze the Quality of Service With themeasurements in hand this section lays the framework toanalyze the distribution of signal strength over residentialareas and roads For this purpose we use two sets of polygonfiles population and road as a base layer that extracts signalstrength from the superimposed coverage map While thefirst helps us to study the effect in static users the latterprovides insight into the coverage for mobile users Furtherwe define different levels from LTE UMTS and GSM signalstrength with which the quality of service enjoyed by theusers can be easily identified e algorithm used for clas-sification of user levels is mentioned in Figure 4e fact thatLTE UMTS and GSM offer better service in the respectiveorder is used for forming the algorithm While RSRPgtminus80 dBm is an excellent signal strength in LTEminus90 dBm lt RSRP lt minus80 dBm offers poorer performancethan the former [21]erefore we assign the former as level1 and the latter as level 2 Following the pattern we assignhigher levels to the LTE and lower levels to UMTS [21] as thedata rate decreases in UMTS compared to LTE is patternis repeated in GSM as well [22]
Note that the points labelled No Signal and NULL arenot considered while assigning levels till level 12 whereNo Signal represents a situation where UEs did not receiveany signal whereas NULL considers a scenario wherepolygon does not have a signal strength to map to Level 13 isused to represent the signal strength that is lesser than theminimum required signal strength for a reliable commu-nication A scenario where the UE cannot make call in any ofthe RAT is considered in level 14 e difference betweenlevel 13 and level 14 is that connection is not possible in level14 while connection may be possible with possible chance ofdisconnection in level 13 [21 23] For example if the deviceunder test has LTE signal strength below minus100 dBm UMTSsignal strength below minus85 dBm and GSM signal strengthbelow minus110 dBm the signal strength values in mobile
4 Mobile Information Systems
phones fall below the minimum recommended signalstrength [21 23] Such a situation is possible in level 13Meanwhile if all devices are not getting any signal from thebase station we assign level 14 which is the worst situationamong all Level 15 does not represent the quality of thesignal as it houses the regions where the measurementcampaign was not performed
321 Framework to Analyze Effects in Residential AreasIn this subsection we study the effect of signal strength onusers in residential areas Figure 5 demonstrates the ex-traction of signal strength from the coverage mape upperlayer is the coverage map which holds the signal strengthvalue e lower layer which is population map in thiscontest extracts signal strength from the overlapping cov-erage map and adds the signal strength value Mk to eachpolygon of the population or road map
In order to extract Mk from an overlapping coveragemap each polygon uses the settings in Table 2 which isexecuted using QGIS a free geographic information
Figure 3 Measurement setup by IQMTEL Sweden
Go to polygon 1
Do nothing
No
Yes
Unprocessedpolygon
No
Points withvalid signal
strength
Pointswithout signal
strength
Inputmeasurements
(points)
Separate points with andwithout signal strengths
Run IDWalgorithm
Run IDWalgorithm
Combine thecoverage maps by
UNION
Outputcoverage map
CNoSig = count of points without measurement in polygonCM = count of points with measurement in polygon
Yes
Assign signal strength ofoutput polygon to
ldquoNO_SIGNALrdquo
If CNoSiggtCM
Figure 2 Algorithm to generate coverage map
Table 1 Measurements across municipalities of Norrbotten
SIno Municipality No of
measurementsArea(km2) Population Road
(km)1 Alvsbyn 708191 17904 8256 53012 Arjeplog 887558 144983 2903 72013 Arvidsjaur 1826754 60857 6490 101994 Boden 2409219 42771 28373 87595 Haparanda 378870 168067 9851 28466 Jokkmokk 2089506 9332 5132 79637 Kalix 940068 193144 16240 65278 Lulea 4603223 18503 78160 7679 Pajala 1821622 206423 6157 1004510 Pitea 3883938 21558 41932 919611 Gallivare 3070680 29139 18023 976612 Kiruna 2315800 25157 23233 730113 Overkalix 325123 81037 3409 521714 Overtornea 671210 32461 4582 5561
Mobile Information Systems 5
system (GIS) software at is the polygon in populationor road map considers those signal strengths from theoverlapping coverage map when the polygon in coveragemap intersects with it In case the population or road mappolygon intersects with multiple polygons of the cov-erage map the algorithm selects one random valueamong them thereby creating a one-to-one mappingwith each polygon in population or road map and signalstrength value
322 Framework to Analyze Effects in Roads Since theroads can stretch to few kilometers and assigning signalstrength to each line is impossible we split the linesrepresenting roads to segments of 100m or less for ab-sorbing information from overlapping coverage map Forexample a road whose length is 1050 km is divided into10 units each of 100m and one unit of length 50m econtribution of the unit of length x where xlt 100m istaken as x100 while calculating total number of segments
Level 3
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SLTE lt ndash90dBm
Level 4
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SUMTS gt ndash60dBm
Level 15
SLTE isin ldquoNULLrdquo ANDSUMTS isin ldquoNULLrdquo AND
SGSM isin ldquoNULLrdquo
Level 10
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SLTE lt ndash100dBm
Level 9
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SGSM lt ndash85dBm
Level 2
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash90dBm lt SLTE lt ndash80dBm
Level 5
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash75dBm lt SUMTS lt ndash60dBm
Level 14
SLTE isin ldquoNo Signalrdquo ANDSUMTS isin ldquoNo Signalrdquo AND
SGSM isin ldquoNo Signalrdquo
Level 11
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash95dBm lt SUMTS lt ndash85dBm
Level 8
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SGSM lt ndash70dBm
Level 1
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SLTE gt ndash80dBm
Level 6
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SUMTS lt ndash75dBm
Level 13
SLTE notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSLTE lt ndash100dBm AND
SUMTS notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSUMTS lt ndash85dBm AND
SGSM notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSGSM lt ndash110dBm AND
Level 12
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SGSM lt ndash100dBm
Level 7
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SGSM gt ndash70dBm
Figure 4 Assigning signal levels
Coverage map
Polygon (population road map)Mk
Zk
Figure 5 Extracting signal strength from coverage map
6 Mobile Information Systems
in a particular level Signal strength value is extractedfrom overlapping coverage map of each RAT SLTE SUMTSand SGSM and is assigned to each line segment As a resultin addition to signal strength value the line segmentobject also carries the length of each segment e linesegment extracts signal strength value from overlappedcoverage map (M) with the settings shown in Table 2 As aresult each line segment object q is a tuple (Zq Mq lq)where lq is the length of the line segment q
Furthermore to analyze the performance of variousoperators to users on road we define two variables λq andϕq e basic logic here is that the coverage poverty expe-rienced by 100 cars in 1 km is the same as that of 1 car in100 km erefore to quantify the coverage poverty wemultiply the number of cars moving through segment q withlq Also to incorporate smaller road segments we normalizethe product by length erefore we define λ for segment q
λq number of cars through q times lq
100 (5)
Since different roads have speed limits we must add thisfactor into consideration as the vehicle stays on road formore time in poor coverage areas erefore we defineanother parameter
ϕq λq times 3600
1000 (6)
where the numerator specifies the speed in (kmhr) and toconvert it to (ms) and we multiply the term by 36 esetwo variables quantify the coverage poverty of absence ofcoverage to the users
4 Data Analysis
41 Signal Strength across Residential Areas inMunicipalitiesHistogram of signal strength is analyzed for various RATsand operators For the ease of comparison we consider LTEby Telia in Lulea and Pajala a comparatively densely pop-ulated municipality and a sparsely populated municipalityrespectively Further the histogram of GSM signal strengthis plotted and compared with that of LTE
Figure 6 shows histogram of GSM signal strength wherethe height of each bar shows the percentage of people fallingin the respective slot Both municipalities have maximumnumber of people in minus70 dBm to minus60 dBm range for GSMAlso the range is the same for most of the municipalities
From Figure 7 we can see that the behaviour in LTE issimilar to that of GSM but majority of people fall inminus100 dBm to minus90 dBm range Most of the municipalitiesshow similar behaviour It is visible that there is a shift inmostly used signal strength in GSM and LTE at is fromFigure 4 it is known that minus70 dBm to minus60 dBm range in RSSI
is an excellent GSM signal strength and minus100 dBm tominus90 dBm LTE signal strength offers only fair service to theusers On the contrary the quality of service offered by LTEfor signal strength from minus100 dBm to minus90 dBm is still betterthan GSM signal strength of minus70 dBm to minus60 dBm
42 Signal Strength across Roads in MunicipalitiesFigure 8 shows the histogram of signal strength for TeliaGSM For fair comparison of histograms generated forresidential areas we consider the same municipalitiesLulea and Pajala Unlike residential areas where bothmunicipalities have maximum number of people inminus70 dBm to minus60 dBm range for GSM roads of thesemunicipalities have maximum number of people inminus90 dBm to minus80 dBm and minus80 dBm to minus70 dBm rangesrespectively It is observed that this shift is common formost of the municipalities Another interesting obser-vation is that the sparsely populated municipality Pajalahas better signal strength in most of its roads despite thelow population density
e LTE signal strength in roads of Pajala is reported inFigure 9 Compared to Figure 8 a decrease in signal strengthis observed Although there is a dip in average signal strengthin LTE the performance at the user end is still better thanthat of GSM Unlike the histograms of residential areaswhere the absence of measurement (ldquoNo Datardquo) is almostzero the percentage of roads without measurement is biggeris is mainly due to the mode of measurement where themeasurements are taken by phones placed in mostly publicutility vehicles
43 Effect of Traffic Pattern In this subsection we quantifythe effect of 3G signal strength on users on roadsFigure 10(a) plots histogram of λ where λ λq1113966 1113967 for various3G operators in Jokkmokk With this approach the bestoperator can be identified Similarly Figure 10(b) plotshistogram of ϕ where ϕ ϕq1113966 1113967 for various 3G operators inJokkmokk While the latter gives the idea about temporalsignal quality experienced by an average user in car theformer shows the number of cars experiencing the signalstrength However both figures have more or less the samepattern
44 Quantifying the Coverage Poverty It is quite clear thatdifferent municipalities get affected in different levels A lowsignal strength in highly populated municipality will havehuge impact compared to a less populated area Figure 11analyzes average GSM signal strength of Telia on totalpopulation of municipalities While the position of circlesrepresents themean signal strength and percentage of peoplewithout service the radius of the circles in scatter plot shows
Table 2 Feature extraction
SI no Option Setting in algorithm1 Geometric predicate Intersect2 Mapping (join type) One-to-one3 Fields to add Signal strength
Mobile Information Systems 7
the population or total road length in respective munici-palities Figure 11(a) reports the percentage of populationwithout signal versus mean signal strength with GSM It is
clear that most of the users in residential areas enjoy fair-quality GSM signal Most of the populated municipalitieshave decent signal quality Also a very small percentage (less
002 0 0 0 004 208
25362812
3999
3940 0450
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
Dat
a
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 188
1117
2877
5455
285 0 0770
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 6 GSM coverage in residential areas (a) Coverage in residential areas of Lulea (b) 2G Coverage in residential areas of Pajala
0 0 005 342
2592
5237
1282 526
0 0 0 0160
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 02 215
1411
4055
18962333
0 0 0 070
25
50
of p
opul
atio
n
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 7 LTE coverage in residential areas (a) 4G coverage in residential areas of Lulea (b) 4G Coverage in residential areas of Pajala
072 0 0 0 213
1838
3635
2649
854 106 0
634
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 599
2526
3426
2127
276 0
1047
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 8 GSM coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
8 Mobile Information Systems
than 15) of residential area is not covered However onanalyzing signal strength on roads in Figure 11(b) a declinein signal strength is observed Although majority of mu-nicipalities get most of their roads under coverage area thereare municipalities like Overtornea where considerablefractions of roads are not covered
45 Signal Strength inUrban Suburban andRest of theArease effect of signal strength to users in residential areas inurban suburban and rest of the areas is reported in Fig-ure 12e term rest of the areas is used to denote residentialareas that do not fall under urban or suburban category eCDF of population is plotted against GSM signal strengthWhile GSM offers best signal strength in urban areas themedium and least signal strengths are observed in suburban
areas and rest of the areas respectively A fraction ofpopulation is under no coverage area of Tele2 and Telenor insuburban areas and rest of the areas However despite theregion classification Telia offers 1ndash4 dB better signal tousers It is also important to note that the results in Figure 12are based only on the available data We have not consideredareas without measurements for analysis
46 ComparisonwithAnother County GSM signal strengthsof two different counties in Sweden Norrbotten andOstergotland are compared in Figure 13 We compare thesignal strengths observed in urban and suburban areas ofboth counties From Figure 13(a) it is clear that despite ofthe county the signal strength in urban areas remains thesame However from 13(b) it can be observed that the user
02 0 276
1711
3728
2718
753051 0 0 0
743
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(a)
0 0 078
89
26813121
1816
3530 0 0
106
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(b)
Figure 9 LTE coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
Telia
0 0 1411131
3518 3448
1152025 009 0
5750
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
Tele2
0
3268
1631 152058
531 436 0 0 0576
0
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Telenor
01032 1448
24813089
867 5080 0 0
5760
25
C
arstimes
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
ndash140
ndash ndash
130
Signal strength (dBm)
(a)
Telia
0 0 1321196
3713 3348
991027 01 0 583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Tele2
0
3458
1722 155 1947
498 242 0 0 0583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0Telenor
01069 152
24863132
896314 0 0 0
5830
25
C
ars times
s
ndash60
ndash ndash5
0
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash90
ndash ndash8
0
ndash140
ndash ndash
130
Signal strength (dBm)
(b)
Figure 10 Effect of traffic pattern (a) Carstimes 100m (b) Carstimes sec
Mobile Information Systems 9
ARJEPLOG
ARVIDSJAUR
BODEN
GAumlLLIVARE
HAPARANDA
JOKKMOKKKALIX
KIRUNALULEAring PAJALA
PITEAringAumlLVSBYNOumlVERKALIX
OumlVERTORNEAring
0
05
1
15
p
opul
atio
n w
ith n
o sig
nal
ndash75 ndash74 ndash73 ndash72 ndash71 ndash70ndash76Mean signal strength (dBm)
(a)
ARJEPLOG
ARVIDSJAURGAumlLLIVARE
HAPARANDA JOKKMOKK
KALIX
KIRUNALULEAring
PAJALA
PITEAringAumlLVSBYN
OumlVERKALIX
OumlVERTORNEAring
0
1
2
3
4
5
6
7
ro
ad w
ith n
o sig
nal
ndash84 ndash83 ndash82 ndash81 ndash80 ndash79 ndash78 ndash77 ndash76ndash85Mean signal strength (dBm)
BODEN
(b)
Figure 11 Impact on of roadspopulation in Telia (a) Residence area (b) Roads
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Suburban
Urban
Rest of thearea
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
0
02
04
06
08
1
CDF
of p
opul
atio
n
Figure 12 Signal strength in urban suburban and rest of the areas
10 Mobile Information Systems
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
To generate the raster each pixel or spatial object musthold the value of an element from a set M erefore anobject O must have two properties
(a) A spatial extent Zi
(b) A function fO that assigns a value from setM to eachpoint in Zi
Considering the search radius r object O is defined as
O Zi MiΨr( 1113857 (2)
us object O is a tuple (Zi MiΨr) where Mi isin M andZi subeR2 e function fO Zi⟶ M whereM R ldquoNO SIGNALrdquo In effect the value fO(xi yi) re-flects the signal strength to be attributed to (xi yi) isin Zi edistance d between neighbouring points in a raster (xi yi)is obtained from equation (1) e signal strength Mi foreach point in raster at location (xi yi) is given as
Mi 1113936
xjyj( 1113857isinSSj xi minus xj1113872 1113873
2+ yi minus yj1113872 1113873
21113874 1113875
minus αΨr xj yj1113872 1113873
1113936xjyj( 1113857isinS
xi minus xj1113872 11138732
+ yi minus yj1113872 11138732
1113874 1113875minusα (3)
Ψr xj yj1113872 1113873fO xj yj1113872 1113873 fO xj yj1113872 1113873 if
xi minus xj1113872 11138732
+ yi minus yj1113872 11138732
1113969
lt r
0 if
x0 minus xj1113872 11138732
+ y0 minus yj1113872 11138732
1113969
gt r
⎧⎪⎪⎨
⎪⎪⎩(4)
where Sj isin S S R ldquoNO SIGNALrdquo and dij is theEuclidean distance between measured point j and point i inthe grid α denotes the distance exponent or power indexwhich is taken as 2 e characteristic function Ψr is definedas in equation (4) where r is the search radius Hence aftersuccessful implementation of (3) on SLTE SUMTS and SGSMwe get MLTE MUMTS and MGSM representing the coveragemap for LTE UMTS and GSM respectively
22 Coverage Specific Aspects To generate coverage map ofTelia Tele2 and Telenor for each LTE UMTS andGSM IDWalgorithm must be carried out to each ensemble of measure-ments dedicated to each of the above operators and RATs eIDW applied to each of these groups of measurements isexplained in Section 21 A simple IDW with all the mea-surements where rdquoNO SIGNALrdquo is also an entry will generatewrong results and therefore needs to be treated separately
d
(xi yi)
Points withmeasurement
r
Points in grid
Figure 1 Selecting points to run IDW algorithm
Mobile Information Systems 3
Here we formulate a coverage specific approach to gen-erate coverage map by taking into account both real signalmeasurements and points with no signal measurements ealgorithm is represented in Figure 2e first step is to separatepoints with valid signal measurements and points withoutsignal strengths and generate coverage map for each set eserasters or grids of points are then converted to polygons Nowthe difference between coveragemaps with validmeasurementsand no signal strengths is createdis output is thenmerged tothe coverage map with valid measurements
It is still possible to have polygons with more pointswithout signal strength and less points with valid mea-surements To address such situations a final step is re-quired at is the polygon is assigned rdquoNO SIGNALrdquowhen the number of points without valid measurements ismore even if there is a valid signal strength assigned to it Inthe absence of such situations the signal strength valueassigned to the final coverage polygon remains the same asthe one from the coverage map generated from validmeasurements
3 Practical Case Study
31 Measurements In order to generate raster we measurethe signal strengths of various operators and RATs with GPScoordinates and time stamps e measurement is made byusing set of mobile phones which are locked to specificoperators and RATse set of mobile phones is kept in a bagas shown in Figure 3 where each phone is locked to a singleoperator and RAT To this end three operators in Sweden arecompared where Tele2 and Telenor share the same infra-structure for 2G (GSM) and 4G (LTE) erefore each bagcontains 2 phones to measure 2G signal and 3 phones tomeasure 3G signal and again 2 phones to measure 4G signalwhich records measurements at regular intervals
We consider three operators Telia Tele2 and Telenorover the Norrbotten region which is the northernmostprovince in Sweden e mobile phones that measure signalstrengths are enclosed in a bag and are placed in vehicles andboats plying through the area under studyemobile phonescollect data namely GPS coordinates date time networktype signal strength operator cell identification code (CID)location area code (LAC) and eNode bid at regular intervalsIt is worth noting that themeasurements from various phonesin the bag are not time-synchronized
e two GSM phones measure broadcast channel (BCCH)and the signal strength measured in GSM is the received signalstrength indicator (RSSI) e 3G RAT used in the phones isuniversal mobile telecommunications system (UMTS) whichis a wideband code divisionmultiple access (WCDMA) systemerefore the mobile phones dedicated to measuring 3Gsignals measure the received power on one code over theprimary common pilot channel (CPICH)is value is referredto as the received signal code power (RSCP) e 4G RAT isalso known as the long-term evolution (LTE) standard whichuses time-frequency resource block with varying channel size(from 14 to 20MHz) erefore the useful power is con-tributed by different resource blocks which is measured asreference signal received power (RSRP)
e 2G and 3G phones are locked to 2G and 3G RATrespectively is means that the mobile phone cannotperform handover operation from 3G to 2Gwhen it has poorsignal strength However the 4G mobile phones are notlocked to RATs and as a result they switch RATfrom LTE toUMTS and then fromUMTS to GSM based on the measuredsignal strength In other words the phones that measureLTE signals provide RSRP values in fewer areas even thoughthere are RSRP values when phone switches to other RATsfrom LTE
e number of measurements received per munici-pality is given in Table 1 In this paper we study thedistribution of signal strength over residential areas androads e population and road lengths associated witheach of the municipalities are listed in the table enumber of measurements per municipality consists of threeRATs and three operators e population map consideredfor analysis is a 1 km times 1 km polygon shape file provided by[19] e road data is given by [20] which provides in-formation about number of vehicles moving through thatparticular road
32 Framework to Analyze the Quality of Service With themeasurements in hand this section lays the framework toanalyze the distribution of signal strength over residentialareas and roads For this purpose we use two sets of polygonfiles population and road as a base layer that extracts signalstrength from the superimposed coverage map While thefirst helps us to study the effect in static users the latterprovides insight into the coverage for mobile users Furtherwe define different levels from LTE UMTS and GSM signalstrength with which the quality of service enjoyed by theusers can be easily identified e algorithm used for clas-sification of user levels is mentioned in Figure 4e fact thatLTE UMTS and GSM offer better service in the respectiveorder is used for forming the algorithm While RSRPgtminus80 dBm is an excellent signal strength in LTEminus90 dBm lt RSRP lt minus80 dBm offers poorer performancethan the former [21]erefore we assign the former as level1 and the latter as level 2 Following the pattern we assignhigher levels to the LTE and lower levels to UMTS [21] as thedata rate decreases in UMTS compared to LTE is patternis repeated in GSM as well [22]
Note that the points labelled No Signal and NULL arenot considered while assigning levels till level 12 whereNo Signal represents a situation where UEs did not receiveany signal whereas NULL considers a scenario wherepolygon does not have a signal strength to map to Level 13 isused to represent the signal strength that is lesser than theminimum required signal strength for a reliable commu-nication A scenario where the UE cannot make call in any ofthe RAT is considered in level 14 e difference betweenlevel 13 and level 14 is that connection is not possible in level14 while connection may be possible with possible chance ofdisconnection in level 13 [21 23] For example if the deviceunder test has LTE signal strength below minus100 dBm UMTSsignal strength below minus85 dBm and GSM signal strengthbelow minus110 dBm the signal strength values in mobile
4 Mobile Information Systems
phones fall below the minimum recommended signalstrength [21 23] Such a situation is possible in level 13Meanwhile if all devices are not getting any signal from thebase station we assign level 14 which is the worst situationamong all Level 15 does not represent the quality of thesignal as it houses the regions where the measurementcampaign was not performed
321 Framework to Analyze Effects in Residential AreasIn this subsection we study the effect of signal strength onusers in residential areas Figure 5 demonstrates the ex-traction of signal strength from the coverage mape upperlayer is the coverage map which holds the signal strengthvalue e lower layer which is population map in thiscontest extracts signal strength from the overlapping cov-erage map and adds the signal strength value Mk to eachpolygon of the population or road map
In order to extract Mk from an overlapping coveragemap each polygon uses the settings in Table 2 which isexecuted using QGIS a free geographic information
Figure 3 Measurement setup by IQMTEL Sweden
Go to polygon 1
Do nothing
No
Yes
Unprocessedpolygon
No
Points withvalid signal
strength
Pointswithout signal
strength
Inputmeasurements
(points)
Separate points with andwithout signal strengths
Run IDWalgorithm
Run IDWalgorithm
Combine thecoverage maps by
UNION
Outputcoverage map
CNoSig = count of points without measurement in polygonCM = count of points with measurement in polygon
Yes
Assign signal strength ofoutput polygon to
ldquoNO_SIGNALrdquo
If CNoSiggtCM
Figure 2 Algorithm to generate coverage map
Table 1 Measurements across municipalities of Norrbotten
SIno Municipality No of
measurementsArea(km2) Population Road
(km)1 Alvsbyn 708191 17904 8256 53012 Arjeplog 887558 144983 2903 72013 Arvidsjaur 1826754 60857 6490 101994 Boden 2409219 42771 28373 87595 Haparanda 378870 168067 9851 28466 Jokkmokk 2089506 9332 5132 79637 Kalix 940068 193144 16240 65278 Lulea 4603223 18503 78160 7679 Pajala 1821622 206423 6157 1004510 Pitea 3883938 21558 41932 919611 Gallivare 3070680 29139 18023 976612 Kiruna 2315800 25157 23233 730113 Overkalix 325123 81037 3409 521714 Overtornea 671210 32461 4582 5561
Mobile Information Systems 5
system (GIS) software at is the polygon in populationor road map considers those signal strengths from theoverlapping coverage map when the polygon in coveragemap intersects with it In case the population or road mappolygon intersects with multiple polygons of the cov-erage map the algorithm selects one random valueamong them thereby creating a one-to-one mappingwith each polygon in population or road map and signalstrength value
322 Framework to Analyze Effects in Roads Since theroads can stretch to few kilometers and assigning signalstrength to each line is impossible we split the linesrepresenting roads to segments of 100m or less for ab-sorbing information from overlapping coverage map Forexample a road whose length is 1050 km is divided into10 units each of 100m and one unit of length 50m econtribution of the unit of length x where xlt 100m istaken as x100 while calculating total number of segments
Level 3
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SLTE lt ndash90dBm
Level 4
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SUMTS gt ndash60dBm
Level 15
SLTE isin ldquoNULLrdquo ANDSUMTS isin ldquoNULLrdquo AND
SGSM isin ldquoNULLrdquo
Level 10
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SLTE lt ndash100dBm
Level 9
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SGSM lt ndash85dBm
Level 2
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash90dBm lt SLTE lt ndash80dBm
Level 5
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash75dBm lt SUMTS lt ndash60dBm
Level 14
SLTE isin ldquoNo Signalrdquo ANDSUMTS isin ldquoNo Signalrdquo AND
SGSM isin ldquoNo Signalrdquo
Level 11
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash95dBm lt SUMTS lt ndash85dBm
Level 8
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SGSM lt ndash70dBm
Level 1
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SLTE gt ndash80dBm
Level 6
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SUMTS lt ndash75dBm
Level 13
SLTE notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSLTE lt ndash100dBm AND
SUMTS notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSUMTS lt ndash85dBm AND
SGSM notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSGSM lt ndash110dBm AND
Level 12
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SGSM lt ndash100dBm
Level 7
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SGSM gt ndash70dBm
Figure 4 Assigning signal levels
Coverage map
Polygon (population road map)Mk
Zk
Figure 5 Extracting signal strength from coverage map
6 Mobile Information Systems
in a particular level Signal strength value is extractedfrom overlapping coverage map of each RAT SLTE SUMTSand SGSM and is assigned to each line segment As a resultin addition to signal strength value the line segmentobject also carries the length of each segment e linesegment extracts signal strength value from overlappedcoverage map (M) with the settings shown in Table 2 As aresult each line segment object q is a tuple (Zq Mq lq)where lq is the length of the line segment q
Furthermore to analyze the performance of variousoperators to users on road we define two variables λq andϕq e basic logic here is that the coverage poverty expe-rienced by 100 cars in 1 km is the same as that of 1 car in100 km erefore to quantify the coverage poverty wemultiply the number of cars moving through segment q withlq Also to incorporate smaller road segments we normalizethe product by length erefore we define λ for segment q
λq number of cars through q times lq
100 (5)
Since different roads have speed limits we must add thisfactor into consideration as the vehicle stays on road formore time in poor coverage areas erefore we defineanother parameter
ϕq λq times 3600
1000 (6)
where the numerator specifies the speed in (kmhr) and toconvert it to (ms) and we multiply the term by 36 esetwo variables quantify the coverage poverty of absence ofcoverage to the users
4 Data Analysis
41 Signal Strength across Residential Areas inMunicipalitiesHistogram of signal strength is analyzed for various RATsand operators For the ease of comparison we consider LTEby Telia in Lulea and Pajala a comparatively densely pop-ulated municipality and a sparsely populated municipalityrespectively Further the histogram of GSM signal strengthis plotted and compared with that of LTE
Figure 6 shows histogram of GSM signal strength wherethe height of each bar shows the percentage of people fallingin the respective slot Both municipalities have maximumnumber of people in minus70 dBm to minus60 dBm range for GSMAlso the range is the same for most of the municipalities
From Figure 7 we can see that the behaviour in LTE issimilar to that of GSM but majority of people fall inminus100 dBm to minus90 dBm range Most of the municipalitiesshow similar behaviour It is visible that there is a shift inmostly used signal strength in GSM and LTE at is fromFigure 4 it is known that minus70 dBm to minus60 dBm range in RSSI
is an excellent GSM signal strength and minus100 dBm tominus90 dBm LTE signal strength offers only fair service to theusers On the contrary the quality of service offered by LTEfor signal strength from minus100 dBm to minus90 dBm is still betterthan GSM signal strength of minus70 dBm to minus60 dBm
42 Signal Strength across Roads in MunicipalitiesFigure 8 shows the histogram of signal strength for TeliaGSM For fair comparison of histograms generated forresidential areas we consider the same municipalitiesLulea and Pajala Unlike residential areas where bothmunicipalities have maximum number of people inminus70 dBm to minus60 dBm range for GSM roads of thesemunicipalities have maximum number of people inminus90 dBm to minus80 dBm and minus80 dBm to minus70 dBm rangesrespectively It is observed that this shift is common formost of the municipalities Another interesting obser-vation is that the sparsely populated municipality Pajalahas better signal strength in most of its roads despite thelow population density
e LTE signal strength in roads of Pajala is reported inFigure 9 Compared to Figure 8 a decrease in signal strengthis observed Although there is a dip in average signal strengthin LTE the performance at the user end is still better thanthat of GSM Unlike the histograms of residential areaswhere the absence of measurement (ldquoNo Datardquo) is almostzero the percentage of roads without measurement is biggeris is mainly due to the mode of measurement where themeasurements are taken by phones placed in mostly publicutility vehicles
43 Effect of Traffic Pattern In this subsection we quantifythe effect of 3G signal strength on users on roadsFigure 10(a) plots histogram of λ where λ λq1113966 1113967 for various3G operators in Jokkmokk With this approach the bestoperator can be identified Similarly Figure 10(b) plotshistogram of ϕ where ϕ ϕq1113966 1113967 for various 3G operators inJokkmokk While the latter gives the idea about temporalsignal quality experienced by an average user in car theformer shows the number of cars experiencing the signalstrength However both figures have more or less the samepattern
44 Quantifying the Coverage Poverty It is quite clear thatdifferent municipalities get affected in different levels A lowsignal strength in highly populated municipality will havehuge impact compared to a less populated area Figure 11analyzes average GSM signal strength of Telia on totalpopulation of municipalities While the position of circlesrepresents themean signal strength and percentage of peoplewithout service the radius of the circles in scatter plot shows
Table 2 Feature extraction
SI no Option Setting in algorithm1 Geometric predicate Intersect2 Mapping (join type) One-to-one3 Fields to add Signal strength
Mobile Information Systems 7
the population or total road length in respective munici-palities Figure 11(a) reports the percentage of populationwithout signal versus mean signal strength with GSM It is
clear that most of the users in residential areas enjoy fair-quality GSM signal Most of the populated municipalitieshave decent signal quality Also a very small percentage (less
002 0 0 0 004 208
25362812
3999
3940 0450
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
Dat
a
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 188
1117
2877
5455
285 0 0770
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 6 GSM coverage in residential areas (a) Coverage in residential areas of Lulea (b) 2G Coverage in residential areas of Pajala
0 0 005 342
2592
5237
1282 526
0 0 0 0160
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 02 215
1411
4055
18962333
0 0 0 070
25
50
of p
opul
atio
n
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 7 LTE coverage in residential areas (a) 4G coverage in residential areas of Lulea (b) 4G Coverage in residential areas of Pajala
072 0 0 0 213
1838
3635
2649
854 106 0
634
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 599
2526
3426
2127
276 0
1047
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 8 GSM coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
8 Mobile Information Systems
than 15) of residential area is not covered However onanalyzing signal strength on roads in Figure 11(b) a declinein signal strength is observed Although majority of mu-nicipalities get most of their roads under coverage area thereare municipalities like Overtornea where considerablefractions of roads are not covered
45 Signal Strength inUrban Suburban andRest of theArease effect of signal strength to users in residential areas inurban suburban and rest of the areas is reported in Fig-ure 12e term rest of the areas is used to denote residentialareas that do not fall under urban or suburban category eCDF of population is plotted against GSM signal strengthWhile GSM offers best signal strength in urban areas themedium and least signal strengths are observed in suburban
areas and rest of the areas respectively A fraction ofpopulation is under no coverage area of Tele2 and Telenor insuburban areas and rest of the areas However despite theregion classification Telia offers 1ndash4 dB better signal tousers It is also important to note that the results in Figure 12are based only on the available data We have not consideredareas without measurements for analysis
46 ComparisonwithAnother County GSM signal strengthsof two different counties in Sweden Norrbotten andOstergotland are compared in Figure 13 We compare thesignal strengths observed in urban and suburban areas ofboth counties From Figure 13(a) it is clear that despite ofthe county the signal strength in urban areas remains thesame However from 13(b) it can be observed that the user
02 0 276
1711
3728
2718
753051 0 0 0
743
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(a)
0 0 078
89
26813121
1816
3530 0 0
106
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(b)
Figure 9 LTE coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
Telia
0 0 1411131
3518 3448
1152025 009 0
5750
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
Tele2
0
3268
1631 152058
531 436 0 0 0576
0
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Telenor
01032 1448
24813089
867 5080 0 0
5760
25
C
arstimes
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
ndash140
ndash ndash
130
Signal strength (dBm)
(a)
Telia
0 0 1321196
3713 3348
991027 01 0 583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Tele2
0
3458
1722 155 1947
498 242 0 0 0583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0Telenor
01069 152
24863132
896314 0 0 0
5830
25
C
ars times
s
ndash60
ndash ndash5
0
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash90
ndash ndash8
0
ndash140
ndash ndash
130
Signal strength (dBm)
(b)
Figure 10 Effect of traffic pattern (a) Carstimes 100m (b) Carstimes sec
Mobile Information Systems 9
ARJEPLOG
ARVIDSJAUR
BODEN
GAumlLLIVARE
HAPARANDA
JOKKMOKKKALIX
KIRUNALULEAring PAJALA
PITEAringAumlLVSBYNOumlVERKALIX
OumlVERTORNEAring
0
05
1
15
p
opul
atio
n w
ith n
o sig
nal
ndash75 ndash74 ndash73 ndash72 ndash71 ndash70ndash76Mean signal strength (dBm)
(a)
ARJEPLOG
ARVIDSJAURGAumlLLIVARE
HAPARANDA JOKKMOKK
KALIX
KIRUNALULEAring
PAJALA
PITEAringAumlLVSBYN
OumlVERKALIX
OumlVERTORNEAring
0
1
2
3
4
5
6
7
ro
ad w
ith n
o sig
nal
ndash84 ndash83 ndash82 ndash81 ndash80 ndash79 ndash78 ndash77 ndash76ndash85Mean signal strength (dBm)
BODEN
(b)
Figure 11 Impact on of roadspopulation in Telia (a) Residence area (b) Roads
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Suburban
Urban
Rest of thearea
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
0
02
04
06
08
1
CDF
of p
opul
atio
n
Figure 12 Signal strength in urban suburban and rest of the areas
10 Mobile Information Systems
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
Here we formulate a coverage specific approach to gen-erate coverage map by taking into account both real signalmeasurements and points with no signal measurements ealgorithm is represented in Figure 2e first step is to separatepoints with valid signal measurements and points withoutsignal strengths and generate coverage map for each set eserasters or grids of points are then converted to polygons Nowthe difference between coveragemaps with validmeasurementsand no signal strengths is createdis output is thenmerged tothe coverage map with valid measurements
It is still possible to have polygons with more pointswithout signal strength and less points with valid mea-surements To address such situations a final step is re-quired at is the polygon is assigned rdquoNO SIGNALrdquowhen the number of points without valid measurements ismore even if there is a valid signal strength assigned to it Inthe absence of such situations the signal strength valueassigned to the final coverage polygon remains the same asthe one from the coverage map generated from validmeasurements
3 Practical Case Study
31 Measurements In order to generate raster we measurethe signal strengths of various operators and RATs with GPScoordinates and time stamps e measurement is made byusing set of mobile phones which are locked to specificoperators and RATse set of mobile phones is kept in a bagas shown in Figure 3 where each phone is locked to a singleoperator and RAT To this end three operators in Sweden arecompared where Tele2 and Telenor share the same infra-structure for 2G (GSM) and 4G (LTE) erefore each bagcontains 2 phones to measure 2G signal and 3 phones tomeasure 3G signal and again 2 phones to measure 4G signalwhich records measurements at regular intervals
We consider three operators Telia Tele2 and Telenorover the Norrbotten region which is the northernmostprovince in Sweden e mobile phones that measure signalstrengths are enclosed in a bag and are placed in vehicles andboats plying through the area under studyemobile phonescollect data namely GPS coordinates date time networktype signal strength operator cell identification code (CID)location area code (LAC) and eNode bid at regular intervalsIt is worth noting that themeasurements from various phonesin the bag are not time-synchronized
e two GSM phones measure broadcast channel (BCCH)and the signal strength measured in GSM is the received signalstrength indicator (RSSI) e 3G RAT used in the phones isuniversal mobile telecommunications system (UMTS) whichis a wideband code divisionmultiple access (WCDMA) systemerefore the mobile phones dedicated to measuring 3Gsignals measure the received power on one code over theprimary common pilot channel (CPICH)is value is referredto as the received signal code power (RSCP) e 4G RAT isalso known as the long-term evolution (LTE) standard whichuses time-frequency resource block with varying channel size(from 14 to 20MHz) erefore the useful power is con-tributed by different resource blocks which is measured asreference signal received power (RSRP)
e 2G and 3G phones are locked to 2G and 3G RATrespectively is means that the mobile phone cannotperform handover operation from 3G to 2Gwhen it has poorsignal strength However the 4G mobile phones are notlocked to RATs and as a result they switch RATfrom LTE toUMTS and then fromUMTS to GSM based on the measuredsignal strength In other words the phones that measureLTE signals provide RSRP values in fewer areas even thoughthere are RSRP values when phone switches to other RATsfrom LTE
e number of measurements received per munici-pality is given in Table 1 In this paper we study thedistribution of signal strength over residential areas androads e population and road lengths associated witheach of the municipalities are listed in the table enumber of measurements per municipality consists of threeRATs and three operators e population map consideredfor analysis is a 1 km times 1 km polygon shape file provided by[19] e road data is given by [20] which provides in-formation about number of vehicles moving through thatparticular road
32 Framework to Analyze the Quality of Service With themeasurements in hand this section lays the framework toanalyze the distribution of signal strength over residentialareas and roads For this purpose we use two sets of polygonfiles population and road as a base layer that extracts signalstrength from the superimposed coverage map While thefirst helps us to study the effect in static users the latterprovides insight into the coverage for mobile users Furtherwe define different levels from LTE UMTS and GSM signalstrength with which the quality of service enjoyed by theusers can be easily identified e algorithm used for clas-sification of user levels is mentioned in Figure 4e fact thatLTE UMTS and GSM offer better service in the respectiveorder is used for forming the algorithm While RSRPgtminus80 dBm is an excellent signal strength in LTEminus90 dBm lt RSRP lt minus80 dBm offers poorer performancethan the former [21]erefore we assign the former as level1 and the latter as level 2 Following the pattern we assignhigher levels to the LTE and lower levels to UMTS [21] as thedata rate decreases in UMTS compared to LTE is patternis repeated in GSM as well [22]
Note that the points labelled No Signal and NULL arenot considered while assigning levels till level 12 whereNo Signal represents a situation where UEs did not receiveany signal whereas NULL considers a scenario wherepolygon does not have a signal strength to map to Level 13 isused to represent the signal strength that is lesser than theminimum required signal strength for a reliable commu-nication A scenario where the UE cannot make call in any ofthe RAT is considered in level 14 e difference betweenlevel 13 and level 14 is that connection is not possible in level14 while connection may be possible with possible chance ofdisconnection in level 13 [21 23] For example if the deviceunder test has LTE signal strength below minus100 dBm UMTSsignal strength below minus85 dBm and GSM signal strengthbelow minus110 dBm the signal strength values in mobile
4 Mobile Information Systems
phones fall below the minimum recommended signalstrength [21 23] Such a situation is possible in level 13Meanwhile if all devices are not getting any signal from thebase station we assign level 14 which is the worst situationamong all Level 15 does not represent the quality of thesignal as it houses the regions where the measurementcampaign was not performed
321 Framework to Analyze Effects in Residential AreasIn this subsection we study the effect of signal strength onusers in residential areas Figure 5 demonstrates the ex-traction of signal strength from the coverage mape upperlayer is the coverage map which holds the signal strengthvalue e lower layer which is population map in thiscontest extracts signal strength from the overlapping cov-erage map and adds the signal strength value Mk to eachpolygon of the population or road map
In order to extract Mk from an overlapping coveragemap each polygon uses the settings in Table 2 which isexecuted using QGIS a free geographic information
Figure 3 Measurement setup by IQMTEL Sweden
Go to polygon 1
Do nothing
No
Yes
Unprocessedpolygon
No
Points withvalid signal
strength
Pointswithout signal
strength
Inputmeasurements
(points)
Separate points with andwithout signal strengths
Run IDWalgorithm
Run IDWalgorithm
Combine thecoverage maps by
UNION
Outputcoverage map
CNoSig = count of points without measurement in polygonCM = count of points with measurement in polygon
Yes
Assign signal strength ofoutput polygon to
ldquoNO_SIGNALrdquo
If CNoSiggtCM
Figure 2 Algorithm to generate coverage map
Table 1 Measurements across municipalities of Norrbotten
SIno Municipality No of
measurementsArea(km2) Population Road
(km)1 Alvsbyn 708191 17904 8256 53012 Arjeplog 887558 144983 2903 72013 Arvidsjaur 1826754 60857 6490 101994 Boden 2409219 42771 28373 87595 Haparanda 378870 168067 9851 28466 Jokkmokk 2089506 9332 5132 79637 Kalix 940068 193144 16240 65278 Lulea 4603223 18503 78160 7679 Pajala 1821622 206423 6157 1004510 Pitea 3883938 21558 41932 919611 Gallivare 3070680 29139 18023 976612 Kiruna 2315800 25157 23233 730113 Overkalix 325123 81037 3409 521714 Overtornea 671210 32461 4582 5561
Mobile Information Systems 5
system (GIS) software at is the polygon in populationor road map considers those signal strengths from theoverlapping coverage map when the polygon in coveragemap intersects with it In case the population or road mappolygon intersects with multiple polygons of the cov-erage map the algorithm selects one random valueamong them thereby creating a one-to-one mappingwith each polygon in population or road map and signalstrength value
322 Framework to Analyze Effects in Roads Since theroads can stretch to few kilometers and assigning signalstrength to each line is impossible we split the linesrepresenting roads to segments of 100m or less for ab-sorbing information from overlapping coverage map Forexample a road whose length is 1050 km is divided into10 units each of 100m and one unit of length 50m econtribution of the unit of length x where xlt 100m istaken as x100 while calculating total number of segments
Level 3
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SLTE lt ndash90dBm
Level 4
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SUMTS gt ndash60dBm
Level 15
SLTE isin ldquoNULLrdquo ANDSUMTS isin ldquoNULLrdquo AND
SGSM isin ldquoNULLrdquo
Level 10
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SLTE lt ndash100dBm
Level 9
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SGSM lt ndash85dBm
Level 2
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash90dBm lt SLTE lt ndash80dBm
Level 5
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash75dBm lt SUMTS lt ndash60dBm
Level 14
SLTE isin ldquoNo Signalrdquo ANDSUMTS isin ldquoNo Signalrdquo AND
SGSM isin ldquoNo Signalrdquo
Level 11
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash95dBm lt SUMTS lt ndash85dBm
Level 8
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SGSM lt ndash70dBm
Level 1
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SLTE gt ndash80dBm
Level 6
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SUMTS lt ndash75dBm
Level 13
SLTE notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSLTE lt ndash100dBm AND
SUMTS notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSUMTS lt ndash85dBm AND
SGSM notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSGSM lt ndash110dBm AND
Level 12
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SGSM lt ndash100dBm
Level 7
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SGSM gt ndash70dBm
Figure 4 Assigning signal levels
Coverage map
Polygon (population road map)Mk
Zk
Figure 5 Extracting signal strength from coverage map
6 Mobile Information Systems
in a particular level Signal strength value is extractedfrom overlapping coverage map of each RAT SLTE SUMTSand SGSM and is assigned to each line segment As a resultin addition to signal strength value the line segmentobject also carries the length of each segment e linesegment extracts signal strength value from overlappedcoverage map (M) with the settings shown in Table 2 As aresult each line segment object q is a tuple (Zq Mq lq)where lq is the length of the line segment q
Furthermore to analyze the performance of variousoperators to users on road we define two variables λq andϕq e basic logic here is that the coverage poverty expe-rienced by 100 cars in 1 km is the same as that of 1 car in100 km erefore to quantify the coverage poverty wemultiply the number of cars moving through segment q withlq Also to incorporate smaller road segments we normalizethe product by length erefore we define λ for segment q
λq number of cars through q times lq
100 (5)
Since different roads have speed limits we must add thisfactor into consideration as the vehicle stays on road formore time in poor coverage areas erefore we defineanother parameter
ϕq λq times 3600
1000 (6)
where the numerator specifies the speed in (kmhr) and toconvert it to (ms) and we multiply the term by 36 esetwo variables quantify the coverage poverty of absence ofcoverage to the users
4 Data Analysis
41 Signal Strength across Residential Areas inMunicipalitiesHistogram of signal strength is analyzed for various RATsand operators For the ease of comparison we consider LTEby Telia in Lulea and Pajala a comparatively densely pop-ulated municipality and a sparsely populated municipalityrespectively Further the histogram of GSM signal strengthis plotted and compared with that of LTE
Figure 6 shows histogram of GSM signal strength wherethe height of each bar shows the percentage of people fallingin the respective slot Both municipalities have maximumnumber of people in minus70 dBm to minus60 dBm range for GSMAlso the range is the same for most of the municipalities
From Figure 7 we can see that the behaviour in LTE issimilar to that of GSM but majority of people fall inminus100 dBm to minus90 dBm range Most of the municipalitiesshow similar behaviour It is visible that there is a shift inmostly used signal strength in GSM and LTE at is fromFigure 4 it is known that minus70 dBm to minus60 dBm range in RSSI
is an excellent GSM signal strength and minus100 dBm tominus90 dBm LTE signal strength offers only fair service to theusers On the contrary the quality of service offered by LTEfor signal strength from minus100 dBm to minus90 dBm is still betterthan GSM signal strength of minus70 dBm to minus60 dBm
42 Signal Strength across Roads in MunicipalitiesFigure 8 shows the histogram of signal strength for TeliaGSM For fair comparison of histograms generated forresidential areas we consider the same municipalitiesLulea and Pajala Unlike residential areas where bothmunicipalities have maximum number of people inminus70 dBm to minus60 dBm range for GSM roads of thesemunicipalities have maximum number of people inminus90 dBm to minus80 dBm and minus80 dBm to minus70 dBm rangesrespectively It is observed that this shift is common formost of the municipalities Another interesting obser-vation is that the sparsely populated municipality Pajalahas better signal strength in most of its roads despite thelow population density
e LTE signal strength in roads of Pajala is reported inFigure 9 Compared to Figure 8 a decrease in signal strengthis observed Although there is a dip in average signal strengthin LTE the performance at the user end is still better thanthat of GSM Unlike the histograms of residential areaswhere the absence of measurement (ldquoNo Datardquo) is almostzero the percentage of roads without measurement is biggeris is mainly due to the mode of measurement where themeasurements are taken by phones placed in mostly publicutility vehicles
43 Effect of Traffic Pattern In this subsection we quantifythe effect of 3G signal strength on users on roadsFigure 10(a) plots histogram of λ where λ λq1113966 1113967 for various3G operators in Jokkmokk With this approach the bestoperator can be identified Similarly Figure 10(b) plotshistogram of ϕ where ϕ ϕq1113966 1113967 for various 3G operators inJokkmokk While the latter gives the idea about temporalsignal quality experienced by an average user in car theformer shows the number of cars experiencing the signalstrength However both figures have more or less the samepattern
44 Quantifying the Coverage Poverty It is quite clear thatdifferent municipalities get affected in different levels A lowsignal strength in highly populated municipality will havehuge impact compared to a less populated area Figure 11analyzes average GSM signal strength of Telia on totalpopulation of municipalities While the position of circlesrepresents themean signal strength and percentage of peoplewithout service the radius of the circles in scatter plot shows
Table 2 Feature extraction
SI no Option Setting in algorithm1 Geometric predicate Intersect2 Mapping (join type) One-to-one3 Fields to add Signal strength
Mobile Information Systems 7
the population or total road length in respective munici-palities Figure 11(a) reports the percentage of populationwithout signal versus mean signal strength with GSM It is
clear that most of the users in residential areas enjoy fair-quality GSM signal Most of the populated municipalitieshave decent signal quality Also a very small percentage (less
002 0 0 0 004 208
25362812
3999
3940 0450
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
Dat
a
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 188
1117
2877
5455
285 0 0770
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 6 GSM coverage in residential areas (a) Coverage in residential areas of Lulea (b) 2G Coverage in residential areas of Pajala
0 0 005 342
2592
5237
1282 526
0 0 0 0160
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 02 215
1411
4055
18962333
0 0 0 070
25
50
of p
opul
atio
n
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 7 LTE coverage in residential areas (a) 4G coverage in residential areas of Lulea (b) 4G Coverage in residential areas of Pajala
072 0 0 0 213
1838
3635
2649
854 106 0
634
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 599
2526
3426
2127
276 0
1047
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 8 GSM coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
8 Mobile Information Systems
than 15) of residential area is not covered However onanalyzing signal strength on roads in Figure 11(b) a declinein signal strength is observed Although majority of mu-nicipalities get most of their roads under coverage area thereare municipalities like Overtornea where considerablefractions of roads are not covered
45 Signal Strength inUrban Suburban andRest of theArease effect of signal strength to users in residential areas inurban suburban and rest of the areas is reported in Fig-ure 12e term rest of the areas is used to denote residentialareas that do not fall under urban or suburban category eCDF of population is plotted against GSM signal strengthWhile GSM offers best signal strength in urban areas themedium and least signal strengths are observed in suburban
areas and rest of the areas respectively A fraction ofpopulation is under no coverage area of Tele2 and Telenor insuburban areas and rest of the areas However despite theregion classification Telia offers 1ndash4 dB better signal tousers It is also important to note that the results in Figure 12are based only on the available data We have not consideredareas without measurements for analysis
46 ComparisonwithAnother County GSM signal strengthsof two different counties in Sweden Norrbotten andOstergotland are compared in Figure 13 We compare thesignal strengths observed in urban and suburban areas ofboth counties From Figure 13(a) it is clear that despite ofthe county the signal strength in urban areas remains thesame However from 13(b) it can be observed that the user
02 0 276
1711
3728
2718
753051 0 0 0
743
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(a)
0 0 078
89
26813121
1816
3530 0 0
106
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(b)
Figure 9 LTE coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
Telia
0 0 1411131
3518 3448
1152025 009 0
5750
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
Tele2
0
3268
1631 152058
531 436 0 0 0576
0
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Telenor
01032 1448
24813089
867 5080 0 0
5760
25
C
arstimes
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
ndash140
ndash ndash
130
Signal strength (dBm)
(a)
Telia
0 0 1321196
3713 3348
991027 01 0 583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Tele2
0
3458
1722 155 1947
498 242 0 0 0583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0Telenor
01069 152
24863132
896314 0 0 0
5830
25
C
ars times
s
ndash60
ndash ndash5
0
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash90
ndash ndash8
0
ndash140
ndash ndash
130
Signal strength (dBm)
(b)
Figure 10 Effect of traffic pattern (a) Carstimes 100m (b) Carstimes sec
Mobile Information Systems 9
ARJEPLOG
ARVIDSJAUR
BODEN
GAumlLLIVARE
HAPARANDA
JOKKMOKKKALIX
KIRUNALULEAring PAJALA
PITEAringAumlLVSBYNOumlVERKALIX
OumlVERTORNEAring
0
05
1
15
p
opul
atio
n w
ith n
o sig
nal
ndash75 ndash74 ndash73 ndash72 ndash71 ndash70ndash76Mean signal strength (dBm)
(a)
ARJEPLOG
ARVIDSJAURGAumlLLIVARE
HAPARANDA JOKKMOKK
KALIX
KIRUNALULEAring
PAJALA
PITEAringAumlLVSBYN
OumlVERKALIX
OumlVERTORNEAring
0
1
2
3
4
5
6
7
ro
ad w
ith n
o sig
nal
ndash84 ndash83 ndash82 ndash81 ndash80 ndash79 ndash78 ndash77 ndash76ndash85Mean signal strength (dBm)
BODEN
(b)
Figure 11 Impact on of roadspopulation in Telia (a) Residence area (b) Roads
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Suburban
Urban
Rest of thearea
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
0
02
04
06
08
1
CDF
of p
opul
atio
n
Figure 12 Signal strength in urban suburban and rest of the areas
10 Mobile Information Systems
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
phones fall below the minimum recommended signalstrength [21 23] Such a situation is possible in level 13Meanwhile if all devices are not getting any signal from thebase station we assign level 14 which is the worst situationamong all Level 15 does not represent the quality of thesignal as it houses the regions where the measurementcampaign was not performed
321 Framework to Analyze Effects in Residential AreasIn this subsection we study the effect of signal strength onusers in residential areas Figure 5 demonstrates the ex-traction of signal strength from the coverage mape upperlayer is the coverage map which holds the signal strengthvalue e lower layer which is population map in thiscontest extracts signal strength from the overlapping cov-erage map and adds the signal strength value Mk to eachpolygon of the population or road map
In order to extract Mk from an overlapping coveragemap each polygon uses the settings in Table 2 which isexecuted using QGIS a free geographic information
Figure 3 Measurement setup by IQMTEL Sweden
Go to polygon 1
Do nothing
No
Yes
Unprocessedpolygon
No
Points withvalid signal
strength
Pointswithout signal
strength
Inputmeasurements
(points)
Separate points with andwithout signal strengths
Run IDWalgorithm
Run IDWalgorithm
Combine thecoverage maps by
UNION
Outputcoverage map
CNoSig = count of points without measurement in polygonCM = count of points with measurement in polygon
Yes
Assign signal strength ofoutput polygon to
ldquoNO_SIGNALrdquo
If CNoSiggtCM
Figure 2 Algorithm to generate coverage map
Table 1 Measurements across municipalities of Norrbotten
SIno Municipality No of
measurementsArea(km2) Population Road
(km)1 Alvsbyn 708191 17904 8256 53012 Arjeplog 887558 144983 2903 72013 Arvidsjaur 1826754 60857 6490 101994 Boden 2409219 42771 28373 87595 Haparanda 378870 168067 9851 28466 Jokkmokk 2089506 9332 5132 79637 Kalix 940068 193144 16240 65278 Lulea 4603223 18503 78160 7679 Pajala 1821622 206423 6157 1004510 Pitea 3883938 21558 41932 919611 Gallivare 3070680 29139 18023 976612 Kiruna 2315800 25157 23233 730113 Overkalix 325123 81037 3409 521714 Overtornea 671210 32461 4582 5561
Mobile Information Systems 5
system (GIS) software at is the polygon in populationor road map considers those signal strengths from theoverlapping coverage map when the polygon in coveragemap intersects with it In case the population or road mappolygon intersects with multiple polygons of the cov-erage map the algorithm selects one random valueamong them thereby creating a one-to-one mappingwith each polygon in population or road map and signalstrength value
322 Framework to Analyze Effects in Roads Since theroads can stretch to few kilometers and assigning signalstrength to each line is impossible we split the linesrepresenting roads to segments of 100m or less for ab-sorbing information from overlapping coverage map Forexample a road whose length is 1050 km is divided into10 units each of 100m and one unit of length 50m econtribution of the unit of length x where xlt 100m istaken as x100 while calculating total number of segments
Level 3
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SLTE lt ndash90dBm
Level 4
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SUMTS gt ndash60dBm
Level 15
SLTE isin ldquoNULLrdquo ANDSUMTS isin ldquoNULLrdquo AND
SGSM isin ldquoNULLrdquo
Level 10
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SLTE lt ndash100dBm
Level 9
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SGSM lt ndash85dBm
Level 2
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash90dBm lt SLTE lt ndash80dBm
Level 5
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash75dBm lt SUMTS lt ndash60dBm
Level 14
SLTE isin ldquoNo Signalrdquo ANDSUMTS isin ldquoNo Signalrdquo AND
SGSM isin ldquoNo Signalrdquo
Level 11
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash95dBm lt SUMTS lt ndash85dBm
Level 8
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SGSM lt ndash70dBm
Level 1
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SLTE gt ndash80dBm
Level 6
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SUMTS lt ndash75dBm
Level 13
SLTE notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSLTE lt ndash100dBm AND
SUMTS notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSUMTS lt ndash85dBm AND
SGSM notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSGSM lt ndash110dBm AND
Level 12
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SGSM lt ndash100dBm
Level 7
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SGSM gt ndash70dBm
Figure 4 Assigning signal levels
Coverage map
Polygon (population road map)Mk
Zk
Figure 5 Extracting signal strength from coverage map
6 Mobile Information Systems
in a particular level Signal strength value is extractedfrom overlapping coverage map of each RAT SLTE SUMTSand SGSM and is assigned to each line segment As a resultin addition to signal strength value the line segmentobject also carries the length of each segment e linesegment extracts signal strength value from overlappedcoverage map (M) with the settings shown in Table 2 As aresult each line segment object q is a tuple (Zq Mq lq)where lq is the length of the line segment q
Furthermore to analyze the performance of variousoperators to users on road we define two variables λq andϕq e basic logic here is that the coverage poverty expe-rienced by 100 cars in 1 km is the same as that of 1 car in100 km erefore to quantify the coverage poverty wemultiply the number of cars moving through segment q withlq Also to incorporate smaller road segments we normalizethe product by length erefore we define λ for segment q
λq number of cars through q times lq
100 (5)
Since different roads have speed limits we must add thisfactor into consideration as the vehicle stays on road formore time in poor coverage areas erefore we defineanother parameter
ϕq λq times 3600
1000 (6)
where the numerator specifies the speed in (kmhr) and toconvert it to (ms) and we multiply the term by 36 esetwo variables quantify the coverage poverty of absence ofcoverage to the users
4 Data Analysis
41 Signal Strength across Residential Areas inMunicipalitiesHistogram of signal strength is analyzed for various RATsand operators For the ease of comparison we consider LTEby Telia in Lulea and Pajala a comparatively densely pop-ulated municipality and a sparsely populated municipalityrespectively Further the histogram of GSM signal strengthis plotted and compared with that of LTE
Figure 6 shows histogram of GSM signal strength wherethe height of each bar shows the percentage of people fallingin the respective slot Both municipalities have maximumnumber of people in minus70 dBm to minus60 dBm range for GSMAlso the range is the same for most of the municipalities
From Figure 7 we can see that the behaviour in LTE issimilar to that of GSM but majority of people fall inminus100 dBm to minus90 dBm range Most of the municipalitiesshow similar behaviour It is visible that there is a shift inmostly used signal strength in GSM and LTE at is fromFigure 4 it is known that minus70 dBm to minus60 dBm range in RSSI
is an excellent GSM signal strength and minus100 dBm tominus90 dBm LTE signal strength offers only fair service to theusers On the contrary the quality of service offered by LTEfor signal strength from minus100 dBm to minus90 dBm is still betterthan GSM signal strength of minus70 dBm to minus60 dBm
42 Signal Strength across Roads in MunicipalitiesFigure 8 shows the histogram of signal strength for TeliaGSM For fair comparison of histograms generated forresidential areas we consider the same municipalitiesLulea and Pajala Unlike residential areas where bothmunicipalities have maximum number of people inminus70 dBm to minus60 dBm range for GSM roads of thesemunicipalities have maximum number of people inminus90 dBm to minus80 dBm and minus80 dBm to minus70 dBm rangesrespectively It is observed that this shift is common formost of the municipalities Another interesting obser-vation is that the sparsely populated municipality Pajalahas better signal strength in most of its roads despite thelow population density
e LTE signal strength in roads of Pajala is reported inFigure 9 Compared to Figure 8 a decrease in signal strengthis observed Although there is a dip in average signal strengthin LTE the performance at the user end is still better thanthat of GSM Unlike the histograms of residential areaswhere the absence of measurement (ldquoNo Datardquo) is almostzero the percentage of roads without measurement is biggeris is mainly due to the mode of measurement where themeasurements are taken by phones placed in mostly publicutility vehicles
43 Effect of Traffic Pattern In this subsection we quantifythe effect of 3G signal strength on users on roadsFigure 10(a) plots histogram of λ where λ λq1113966 1113967 for various3G operators in Jokkmokk With this approach the bestoperator can be identified Similarly Figure 10(b) plotshistogram of ϕ where ϕ ϕq1113966 1113967 for various 3G operators inJokkmokk While the latter gives the idea about temporalsignal quality experienced by an average user in car theformer shows the number of cars experiencing the signalstrength However both figures have more or less the samepattern
44 Quantifying the Coverage Poverty It is quite clear thatdifferent municipalities get affected in different levels A lowsignal strength in highly populated municipality will havehuge impact compared to a less populated area Figure 11analyzes average GSM signal strength of Telia on totalpopulation of municipalities While the position of circlesrepresents themean signal strength and percentage of peoplewithout service the radius of the circles in scatter plot shows
Table 2 Feature extraction
SI no Option Setting in algorithm1 Geometric predicate Intersect2 Mapping (join type) One-to-one3 Fields to add Signal strength
Mobile Information Systems 7
the population or total road length in respective munici-palities Figure 11(a) reports the percentage of populationwithout signal versus mean signal strength with GSM It is
clear that most of the users in residential areas enjoy fair-quality GSM signal Most of the populated municipalitieshave decent signal quality Also a very small percentage (less
002 0 0 0 004 208
25362812
3999
3940 0450
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
Dat
a
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 188
1117
2877
5455
285 0 0770
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 6 GSM coverage in residential areas (a) Coverage in residential areas of Lulea (b) 2G Coverage in residential areas of Pajala
0 0 005 342
2592
5237
1282 526
0 0 0 0160
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 02 215
1411
4055
18962333
0 0 0 070
25
50
of p
opul
atio
n
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 7 LTE coverage in residential areas (a) 4G coverage in residential areas of Lulea (b) 4G Coverage in residential areas of Pajala
072 0 0 0 213
1838
3635
2649
854 106 0
634
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 599
2526
3426
2127
276 0
1047
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 8 GSM coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
8 Mobile Information Systems
than 15) of residential area is not covered However onanalyzing signal strength on roads in Figure 11(b) a declinein signal strength is observed Although majority of mu-nicipalities get most of their roads under coverage area thereare municipalities like Overtornea where considerablefractions of roads are not covered
45 Signal Strength inUrban Suburban andRest of theArease effect of signal strength to users in residential areas inurban suburban and rest of the areas is reported in Fig-ure 12e term rest of the areas is used to denote residentialareas that do not fall under urban or suburban category eCDF of population is plotted against GSM signal strengthWhile GSM offers best signal strength in urban areas themedium and least signal strengths are observed in suburban
areas and rest of the areas respectively A fraction ofpopulation is under no coverage area of Tele2 and Telenor insuburban areas and rest of the areas However despite theregion classification Telia offers 1ndash4 dB better signal tousers It is also important to note that the results in Figure 12are based only on the available data We have not consideredareas without measurements for analysis
46 ComparisonwithAnother County GSM signal strengthsof two different counties in Sweden Norrbotten andOstergotland are compared in Figure 13 We compare thesignal strengths observed in urban and suburban areas ofboth counties From Figure 13(a) it is clear that despite ofthe county the signal strength in urban areas remains thesame However from 13(b) it can be observed that the user
02 0 276
1711
3728
2718
753051 0 0 0
743
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(a)
0 0 078
89
26813121
1816
3530 0 0
106
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(b)
Figure 9 LTE coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
Telia
0 0 1411131
3518 3448
1152025 009 0
5750
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
Tele2
0
3268
1631 152058
531 436 0 0 0576
0
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Telenor
01032 1448
24813089
867 5080 0 0
5760
25
C
arstimes
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
ndash140
ndash ndash
130
Signal strength (dBm)
(a)
Telia
0 0 1321196
3713 3348
991027 01 0 583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Tele2
0
3458
1722 155 1947
498 242 0 0 0583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0Telenor
01069 152
24863132
896314 0 0 0
5830
25
C
ars times
s
ndash60
ndash ndash5
0
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash90
ndash ndash8
0
ndash140
ndash ndash
130
Signal strength (dBm)
(b)
Figure 10 Effect of traffic pattern (a) Carstimes 100m (b) Carstimes sec
Mobile Information Systems 9
ARJEPLOG
ARVIDSJAUR
BODEN
GAumlLLIVARE
HAPARANDA
JOKKMOKKKALIX
KIRUNALULEAring PAJALA
PITEAringAumlLVSBYNOumlVERKALIX
OumlVERTORNEAring
0
05
1
15
p
opul
atio
n w
ith n
o sig
nal
ndash75 ndash74 ndash73 ndash72 ndash71 ndash70ndash76Mean signal strength (dBm)
(a)
ARJEPLOG
ARVIDSJAURGAumlLLIVARE
HAPARANDA JOKKMOKK
KALIX
KIRUNALULEAring
PAJALA
PITEAringAumlLVSBYN
OumlVERKALIX
OumlVERTORNEAring
0
1
2
3
4
5
6
7
ro
ad w
ith n
o sig
nal
ndash84 ndash83 ndash82 ndash81 ndash80 ndash79 ndash78 ndash77 ndash76ndash85Mean signal strength (dBm)
BODEN
(b)
Figure 11 Impact on of roadspopulation in Telia (a) Residence area (b) Roads
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Suburban
Urban
Rest of thearea
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
0
02
04
06
08
1
CDF
of p
opul
atio
n
Figure 12 Signal strength in urban suburban and rest of the areas
10 Mobile Information Systems
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
system (GIS) software at is the polygon in populationor road map considers those signal strengths from theoverlapping coverage map when the polygon in coveragemap intersects with it In case the population or road mappolygon intersects with multiple polygons of the cov-erage map the algorithm selects one random valueamong them thereby creating a one-to-one mappingwith each polygon in population or road map and signalstrength value
322 Framework to Analyze Effects in Roads Since theroads can stretch to few kilometers and assigning signalstrength to each line is impossible we split the linesrepresenting roads to segments of 100m or less for ab-sorbing information from overlapping coverage map Forexample a road whose length is 1050 km is divided into10 units each of 100m and one unit of length 50m econtribution of the unit of length x where xlt 100m istaken as x100 while calculating total number of segments
Level 3
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SLTE lt ndash90dBm
Level 4
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SUMTS gt ndash60dBm
Level 15
SLTE isin ldquoNULLrdquo ANDSUMTS isin ldquoNULLrdquo AND
SGSM isin ldquoNULLrdquo
Level 10
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SLTE lt ndash100dBm
Level 9
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash100dBm lt SGSM lt ndash85dBm
Level 2
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash90dBm lt SLTE lt ndash80dBm
Level 5
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash75dBm lt SUMTS lt ndash60dBm
Level 14
SLTE isin ldquoNo Signalrdquo ANDSUMTS isin ldquoNo Signalrdquo AND
SGSM isin ldquoNo Signalrdquo
Level 11
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash95dBm lt SUMTS lt ndash85dBm
Level 8
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SGSM lt ndash70dBm
Level 1
SLTE notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SLTE gt ndash80dBm
Level 6
SUMTS notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash85dBm lt SUMTS lt ndash75dBm
Level 13
SLTE notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSLTE lt ndash100dBm AND
SUMTS notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSUMTS lt ndash85dBm AND
SGSM notin ldquoNULLrdquo ldquoNo Signalrdquo ANDSGSM lt ndash110dBm AND
Level 12
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
ndash110dBm lt SGSM lt ndash100dBm
Level 7
SGSM notin ldquoNo Signalrdquo ldquoNULLrdquoAND
SGSM gt ndash70dBm
Figure 4 Assigning signal levels
Coverage map
Polygon (population road map)Mk
Zk
Figure 5 Extracting signal strength from coverage map
6 Mobile Information Systems
in a particular level Signal strength value is extractedfrom overlapping coverage map of each RAT SLTE SUMTSand SGSM and is assigned to each line segment As a resultin addition to signal strength value the line segmentobject also carries the length of each segment e linesegment extracts signal strength value from overlappedcoverage map (M) with the settings shown in Table 2 As aresult each line segment object q is a tuple (Zq Mq lq)where lq is the length of the line segment q
Furthermore to analyze the performance of variousoperators to users on road we define two variables λq andϕq e basic logic here is that the coverage poverty expe-rienced by 100 cars in 1 km is the same as that of 1 car in100 km erefore to quantify the coverage poverty wemultiply the number of cars moving through segment q withlq Also to incorporate smaller road segments we normalizethe product by length erefore we define λ for segment q
λq number of cars through q times lq
100 (5)
Since different roads have speed limits we must add thisfactor into consideration as the vehicle stays on road formore time in poor coverage areas erefore we defineanother parameter
ϕq λq times 3600
1000 (6)
where the numerator specifies the speed in (kmhr) and toconvert it to (ms) and we multiply the term by 36 esetwo variables quantify the coverage poverty of absence ofcoverage to the users
4 Data Analysis
41 Signal Strength across Residential Areas inMunicipalitiesHistogram of signal strength is analyzed for various RATsand operators For the ease of comparison we consider LTEby Telia in Lulea and Pajala a comparatively densely pop-ulated municipality and a sparsely populated municipalityrespectively Further the histogram of GSM signal strengthis plotted and compared with that of LTE
Figure 6 shows histogram of GSM signal strength wherethe height of each bar shows the percentage of people fallingin the respective slot Both municipalities have maximumnumber of people in minus70 dBm to minus60 dBm range for GSMAlso the range is the same for most of the municipalities
From Figure 7 we can see that the behaviour in LTE issimilar to that of GSM but majority of people fall inminus100 dBm to minus90 dBm range Most of the municipalitiesshow similar behaviour It is visible that there is a shift inmostly used signal strength in GSM and LTE at is fromFigure 4 it is known that minus70 dBm to minus60 dBm range in RSSI
is an excellent GSM signal strength and minus100 dBm tominus90 dBm LTE signal strength offers only fair service to theusers On the contrary the quality of service offered by LTEfor signal strength from minus100 dBm to minus90 dBm is still betterthan GSM signal strength of minus70 dBm to minus60 dBm
42 Signal Strength across Roads in MunicipalitiesFigure 8 shows the histogram of signal strength for TeliaGSM For fair comparison of histograms generated forresidential areas we consider the same municipalitiesLulea and Pajala Unlike residential areas where bothmunicipalities have maximum number of people inminus70 dBm to minus60 dBm range for GSM roads of thesemunicipalities have maximum number of people inminus90 dBm to minus80 dBm and minus80 dBm to minus70 dBm rangesrespectively It is observed that this shift is common formost of the municipalities Another interesting obser-vation is that the sparsely populated municipality Pajalahas better signal strength in most of its roads despite thelow population density
e LTE signal strength in roads of Pajala is reported inFigure 9 Compared to Figure 8 a decrease in signal strengthis observed Although there is a dip in average signal strengthin LTE the performance at the user end is still better thanthat of GSM Unlike the histograms of residential areaswhere the absence of measurement (ldquoNo Datardquo) is almostzero the percentage of roads without measurement is biggeris is mainly due to the mode of measurement where themeasurements are taken by phones placed in mostly publicutility vehicles
43 Effect of Traffic Pattern In this subsection we quantifythe effect of 3G signal strength on users on roadsFigure 10(a) plots histogram of λ where λ λq1113966 1113967 for various3G operators in Jokkmokk With this approach the bestoperator can be identified Similarly Figure 10(b) plotshistogram of ϕ where ϕ ϕq1113966 1113967 for various 3G operators inJokkmokk While the latter gives the idea about temporalsignal quality experienced by an average user in car theformer shows the number of cars experiencing the signalstrength However both figures have more or less the samepattern
44 Quantifying the Coverage Poverty It is quite clear thatdifferent municipalities get affected in different levels A lowsignal strength in highly populated municipality will havehuge impact compared to a less populated area Figure 11analyzes average GSM signal strength of Telia on totalpopulation of municipalities While the position of circlesrepresents themean signal strength and percentage of peoplewithout service the radius of the circles in scatter plot shows
Table 2 Feature extraction
SI no Option Setting in algorithm1 Geometric predicate Intersect2 Mapping (join type) One-to-one3 Fields to add Signal strength
Mobile Information Systems 7
the population or total road length in respective munici-palities Figure 11(a) reports the percentage of populationwithout signal versus mean signal strength with GSM It is
clear that most of the users in residential areas enjoy fair-quality GSM signal Most of the populated municipalitieshave decent signal quality Also a very small percentage (less
002 0 0 0 004 208
25362812
3999
3940 0450
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
Dat
a
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 188
1117
2877
5455
285 0 0770
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 6 GSM coverage in residential areas (a) Coverage in residential areas of Lulea (b) 2G Coverage in residential areas of Pajala
0 0 005 342
2592
5237
1282 526
0 0 0 0160
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 02 215
1411
4055
18962333
0 0 0 070
25
50
of p
opul
atio
n
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 7 LTE coverage in residential areas (a) 4G coverage in residential areas of Lulea (b) 4G Coverage in residential areas of Pajala
072 0 0 0 213
1838
3635
2649
854 106 0
634
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 599
2526
3426
2127
276 0
1047
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 8 GSM coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
8 Mobile Information Systems
than 15) of residential area is not covered However onanalyzing signal strength on roads in Figure 11(b) a declinein signal strength is observed Although majority of mu-nicipalities get most of their roads under coverage area thereare municipalities like Overtornea where considerablefractions of roads are not covered
45 Signal Strength inUrban Suburban andRest of theArease effect of signal strength to users in residential areas inurban suburban and rest of the areas is reported in Fig-ure 12e term rest of the areas is used to denote residentialareas that do not fall under urban or suburban category eCDF of population is plotted against GSM signal strengthWhile GSM offers best signal strength in urban areas themedium and least signal strengths are observed in suburban
areas and rest of the areas respectively A fraction ofpopulation is under no coverage area of Tele2 and Telenor insuburban areas and rest of the areas However despite theregion classification Telia offers 1ndash4 dB better signal tousers It is also important to note that the results in Figure 12are based only on the available data We have not consideredareas without measurements for analysis
46 ComparisonwithAnother County GSM signal strengthsof two different counties in Sweden Norrbotten andOstergotland are compared in Figure 13 We compare thesignal strengths observed in urban and suburban areas ofboth counties From Figure 13(a) it is clear that despite ofthe county the signal strength in urban areas remains thesame However from 13(b) it can be observed that the user
02 0 276
1711
3728
2718
753051 0 0 0
743
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(a)
0 0 078
89
26813121
1816
3530 0 0
106
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(b)
Figure 9 LTE coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
Telia
0 0 1411131
3518 3448
1152025 009 0
5750
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
Tele2
0
3268
1631 152058
531 436 0 0 0576
0
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Telenor
01032 1448
24813089
867 5080 0 0
5760
25
C
arstimes
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
ndash140
ndash ndash
130
Signal strength (dBm)
(a)
Telia
0 0 1321196
3713 3348
991027 01 0 583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Tele2
0
3458
1722 155 1947
498 242 0 0 0583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0Telenor
01069 152
24863132
896314 0 0 0
5830
25
C
ars times
s
ndash60
ndash ndash5
0
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash90
ndash ndash8
0
ndash140
ndash ndash
130
Signal strength (dBm)
(b)
Figure 10 Effect of traffic pattern (a) Carstimes 100m (b) Carstimes sec
Mobile Information Systems 9
ARJEPLOG
ARVIDSJAUR
BODEN
GAumlLLIVARE
HAPARANDA
JOKKMOKKKALIX
KIRUNALULEAring PAJALA
PITEAringAumlLVSBYNOumlVERKALIX
OumlVERTORNEAring
0
05
1
15
p
opul
atio
n w
ith n
o sig
nal
ndash75 ndash74 ndash73 ndash72 ndash71 ndash70ndash76Mean signal strength (dBm)
(a)
ARJEPLOG
ARVIDSJAURGAumlLLIVARE
HAPARANDA JOKKMOKK
KALIX
KIRUNALULEAring
PAJALA
PITEAringAumlLVSBYN
OumlVERKALIX
OumlVERTORNEAring
0
1
2
3
4
5
6
7
ro
ad w
ith n
o sig
nal
ndash84 ndash83 ndash82 ndash81 ndash80 ndash79 ndash78 ndash77 ndash76ndash85Mean signal strength (dBm)
BODEN
(b)
Figure 11 Impact on of roadspopulation in Telia (a) Residence area (b) Roads
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Suburban
Urban
Rest of thearea
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
0
02
04
06
08
1
CDF
of p
opul
atio
n
Figure 12 Signal strength in urban suburban and rest of the areas
10 Mobile Information Systems
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
in a particular level Signal strength value is extractedfrom overlapping coverage map of each RAT SLTE SUMTSand SGSM and is assigned to each line segment As a resultin addition to signal strength value the line segmentobject also carries the length of each segment e linesegment extracts signal strength value from overlappedcoverage map (M) with the settings shown in Table 2 As aresult each line segment object q is a tuple (Zq Mq lq)where lq is the length of the line segment q
Furthermore to analyze the performance of variousoperators to users on road we define two variables λq andϕq e basic logic here is that the coverage poverty expe-rienced by 100 cars in 1 km is the same as that of 1 car in100 km erefore to quantify the coverage poverty wemultiply the number of cars moving through segment q withlq Also to incorporate smaller road segments we normalizethe product by length erefore we define λ for segment q
λq number of cars through q times lq
100 (5)
Since different roads have speed limits we must add thisfactor into consideration as the vehicle stays on road formore time in poor coverage areas erefore we defineanother parameter
ϕq λq times 3600
1000 (6)
where the numerator specifies the speed in (kmhr) and toconvert it to (ms) and we multiply the term by 36 esetwo variables quantify the coverage poverty of absence ofcoverage to the users
4 Data Analysis
41 Signal Strength across Residential Areas inMunicipalitiesHistogram of signal strength is analyzed for various RATsand operators For the ease of comparison we consider LTEby Telia in Lulea and Pajala a comparatively densely pop-ulated municipality and a sparsely populated municipalityrespectively Further the histogram of GSM signal strengthis plotted and compared with that of LTE
Figure 6 shows histogram of GSM signal strength wherethe height of each bar shows the percentage of people fallingin the respective slot Both municipalities have maximumnumber of people in minus70 dBm to minus60 dBm range for GSMAlso the range is the same for most of the municipalities
From Figure 7 we can see that the behaviour in LTE issimilar to that of GSM but majority of people fall inminus100 dBm to minus90 dBm range Most of the municipalitiesshow similar behaviour It is visible that there is a shift inmostly used signal strength in GSM and LTE at is fromFigure 4 it is known that minus70 dBm to minus60 dBm range in RSSI
is an excellent GSM signal strength and minus100 dBm tominus90 dBm LTE signal strength offers only fair service to theusers On the contrary the quality of service offered by LTEfor signal strength from minus100 dBm to minus90 dBm is still betterthan GSM signal strength of minus70 dBm to minus60 dBm
42 Signal Strength across Roads in MunicipalitiesFigure 8 shows the histogram of signal strength for TeliaGSM For fair comparison of histograms generated forresidential areas we consider the same municipalitiesLulea and Pajala Unlike residential areas where bothmunicipalities have maximum number of people inminus70 dBm to minus60 dBm range for GSM roads of thesemunicipalities have maximum number of people inminus90 dBm to minus80 dBm and minus80 dBm to minus70 dBm rangesrespectively It is observed that this shift is common formost of the municipalities Another interesting obser-vation is that the sparsely populated municipality Pajalahas better signal strength in most of its roads despite thelow population density
e LTE signal strength in roads of Pajala is reported inFigure 9 Compared to Figure 8 a decrease in signal strengthis observed Although there is a dip in average signal strengthin LTE the performance at the user end is still better thanthat of GSM Unlike the histograms of residential areaswhere the absence of measurement (ldquoNo Datardquo) is almostzero the percentage of roads without measurement is biggeris is mainly due to the mode of measurement where themeasurements are taken by phones placed in mostly publicutility vehicles
43 Effect of Traffic Pattern In this subsection we quantifythe effect of 3G signal strength on users on roadsFigure 10(a) plots histogram of λ where λ λq1113966 1113967 for various3G operators in Jokkmokk With this approach the bestoperator can be identified Similarly Figure 10(b) plotshistogram of ϕ where ϕ ϕq1113966 1113967 for various 3G operators inJokkmokk While the latter gives the idea about temporalsignal quality experienced by an average user in car theformer shows the number of cars experiencing the signalstrength However both figures have more or less the samepattern
44 Quantifying the Coverage Poverty It is quite clear thatdifferent municipalities get affected in different levels A lowsignal strength in highly populated municipality will havehuge impact compared to a less populated area Figure 11analyzes average GSM signal strength of Telia on totalpopulation of municipalities While the position of circlesrepresents themean signal strength and percentage of peoplewithout service the radius of the circles in scatter plot shows
Table 2 Feature extraction
SI no Option Setting in algorithm1 Geometric predicate Intersect2 Mapping (join type) One-to-one3 Fields to add Signal strength
Mobile Information Systems 7
the population or total road length in respective munici-palities Figure 11(a) reports the percentage of populationwithout signal versus mean signal strength with GSM It is
clear that most of the users in residential areas enjoy fair-quality GSM signal Most of the populated municipalitieshave decent signal quality Also a very small percentage (less
002 0 0 0 004 208
25362812
3999
3940 0450
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
Dat
a
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 188
1117
2877
5455
285 0 0770
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 6 GSM coverage in residential areas (a) Coverage in residential areas of Lulea (b) 2G Coverage in residential areas of Pajala
0 0 005 342
2592
5237
1282 526
0 0 0 0160
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 02 215
1411
4055
18962333
0 0 0 070
25
50
of p
opul
atio
n
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 7 LTE coverage in residential areas (a) 4G coverage in residential areas of Lulea (b) 4G Coverage in residential areas of Pajala
072 0 0 0 213
1838
3635
2649
854 106 0
634
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 599
2526
3426
2127
276 0
1047
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 8 GSM coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
8 Mobile Information Systems
than 15) of residential area is not covered However onanalyzing signal strength on roads in Figure 11(b) a declinein signal strength is observed Although majority of mu-nicipalities get most of their roads under coverage area thereare municipalities like Overtornea where considerablefractions of roads are not covered
45 Signal Strength inUrban Suburban andRest of theArease effect of signal strength to users in residential areas inurban suburban and rest of the areas is reported in Fig-ure 12e term rest of the areas is used to denote residentialareas that do not fall under urban or suburban category eCDF of population is plotted against GSM signal strengthWhile GSM offers best signal strength in urban areas themedium and least signal strengths are observed in suburban
areas and rest of the areas respectively A fraction ofpopulation is under no coverage area of Tele2 and Telenor insuburban areas and rest of the areas However despite theregion classification Telia offers 1ndash4 dB better signal tousers It is also important to note that the results in Figure 12are based only on the available data We have not consideredareas without measurements for analysis
46 ComparisonwithAnother County GSM signal strengthsof two different counties in Sweden Norrbotten andOstergotland are compared in Figure 13 We compare thesignal strengths observed in urban and suburban areas ofboth counties From Figure 13(a) it is clear that despite ofthe county the signal strength in urban areas remains thesame However from 13(b) it can be observed that the user
02 0 276
1711
3728
2718
753051 0 0 0
743
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(a)
0 0 078
89
26813121
1816
3530 0 0
106
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(b)
Figure 9 LTE coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
Telia
0 0 1411131
3518 3448
1152025 009 0
5750
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
Tele2
0
3268
1631 152058
531 436 0 0 0576
0
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Telenor
01032 1448
24813089
867 5080 0 0
5760
25
C
arstimes
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
ndash140
ndash ndash
130
Signal strength (dBm)
(a)
Telia
0 0 1321196
3713 3348
991027 01 0 583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Tele2
0
3458
1722 155 1947
498 242 0 0 0583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0Telenor
01069 152
24863132
896314 0 0 0
5830
25
C
ars times
s
ndash60
ndash ndash5
0
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash90
ndash ndash8
0
ndash140
ndash ndash
130
Signal strength (dBm)
(b)
Figure 10 Effect of traffic pattern (a) Carstimes 100m (b) Carstimes sec
Mobile Information Systems 9
ARJEPLOG
ARVIDSJAUR
BODEN
GAumlLLIVARE
HAPARANDA
JOKKMOKKKALIX
KIRUNALULEAring PAJALA
PITEAringAumlLVSBYNOumlVERKALIX
OumlVERTORNEAring
0
05
1
15
p
opul
atio
n w
ith n
o sig
nal
ndash75 ndash74 ndash73 ndash72 ndash71 ndash70ndash76Mean signal strength (dBm)
(a)
ARJEPLOG
ARVIDSJAURGAumlLLIVARE
HAPARANDA JOKKMOKK
KALIX
KIRUNALULEAring
PAJALA
PITEAringAumlLVSBYN
OumlVERKALIX
OumlVERTORNEAring
0
1
2
3
4
5
6
7
ro
ad w
ith n
o sig
nal
ndash84 ndash83 ndash82 ndash81 ndash80 ndash79 ndash78 ndash77 ndash76ndash85Mean signal strength (dBm)
BODEN
(b)
Figure 11 Impact on of roadspopulation in Telia (a) Residence area (b) Roads
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Suburban
Urban
Rest of thearea
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
0
02
04
06
08
1
CDF
of p
opul
atio
n
Figure 12 Signal strength in urban suburban and rest of the areas
10 Mobile Information Systems
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
the population or total road length in respective munici-palities Figure 11(a) reports the percentage of populationwithout signal versus mean signal strength with GSM It is
clear that most of the users in residential areas enjoy fair-quality GSM signal Most of the populated municipalitieshave decent signal quality Also a very small percentage (less
002 0 0 0 004 208
25362812
3999
3940 0450
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
Dat
a
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 188
1117
2877
5455
285 0 0770
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 6 GSM coverage in residential areas (a) Coverage in residential areas of Lulea (b) 2G Coverage in residential areas of Pajala
0 0 005 342
2592
5237
1282 526
0 0 0 0160
25
50
o
f pop
ulat
ion
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 02 215
1411
4055
18962333
0 0 0 070
25
50
of p
opul
atio
n
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 7 LTE coverage in residential areas (a) 4G coverage in residential areas of Lulea (b) 4G Coverage in residential areas of Pajala
072 0 0 0 213
1838
3635
2649
854 106 0
634
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(a)
0 0 0 0 0 599
2526
3426
2127
276 0
1047
0
25
50
o
f roa
ds
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash50
ndash ndash4
0
ndash60
ndash ndash5
0
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
No
data
No
signa
l
ndash120
ndash ndash
110
ndash110
ndash ndash
100
Signal strength (dBm)
(b)
Figure 8 GSM coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
8 Mobile Information Systems
than 15) of residential area is not covered However onanalyzing signal strength on roads in Figure 11(b) a declinein signal strength is observed Although majority of mu-nicipalities get most of their roads under coverage area thereare municipalities like Overtornea where considerablefractions of roads are not covered
45 Signal Strength inUrban Suburban andRest of theArease effect of signal strength to users in residential areas inurban suburban and rest of the areas is reported in Fig-ure 12e term rest of the areas is used to denote residentialareas that do not fall under urban or suburban category eCDF of population is plotted against GSM signal strengthWhile GSM offers best signal strength in urban areas themedium and least signal strengths are observed in suburban
areas and rest of the areas respectively A fraction ofpopulation is under no coverage area of Tele2 and Telenor insuburban areas and rest of the areas However despite theregion classification Telia offers 1ndash4 dB better signal tousers It is also important to note that the results in Figure 12are based only on the available data We have not consideredareas without measurements for analysis
46 ComparisonwithAnother County GSM signal strengthsof two different counties in Sweden Norrbotten andOstergotland are compared in Figure 13 We compare thesignal strengths observed in urban and suburban areas ofboth counties From Figure 13(a) it is clear that despite ofthe county the signal strength in urban areas remains thesame However from 13(b) it can be observed that the user
02 0 276
1711
3728
2718
753051 0 0 0
743
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(a)
0 0 078
89
26813121
1816
3530 0 0
106
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(b)
Figure 9 LTE coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
Telia
0 0 1411131
3518 3448
1152025 009 0
5750
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
Tele2
0
3268
1631 152058
531 436 0 0 0576
0
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Telenor
01032 1448
24813089
867 5080 0 0
5760
25
C
arstimes
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
ndash140
ndash ndash
130
Signal strength (dBm)
(a)
Telia
0 0 1321196
3713 3348
991027 01 0 583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Tele2
0
3458
1722 155 1947
498 242 0 0 0583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0Telenor
01069 152
24863132
896314 0 0 0
5830
25
C
ars times
s
ndash60
ndash ndash5
0
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash90
ndash ndash8
0
ndash140
ndash ndash
130
Signal strength (dBm)
(b)
Figure 10 Effect of traffic pattern (a) Carstimes 100m (b) Carstimes sec
Mobile Information Systems 9
ARJEPLOG
ARVIDSJAUR
BODEN
GAumlLLIVARE
HAPARANDA
JOKKMOKKKALIX
KIRUNALULEAring PAJALA
PITEAringAumlLVSBYNOumlVERKALIX
OumlVERTORNEAring
0
05
1
15
p
opul
atio
n w
ith n
o sig
nal
ndash75 ndash74 ndash73 ndash72 ndash71 ndash70ndash76Mean signal strength (dBm)
(a)
ARJEPLOG
ARVIDSJAURGAumlLLIVARE
HAPARANDA JOKKMOKK
KALIX
KIRUNALULEAring
PAJALA
PITEAringAumlLVSBYN
OumlVERKALIX
OumlVERTORNEAring
0
1
2
3
4
5
6
7
ro
ad w
ith n
o sig
nal
ndash84 ndash83 ndash82 ndash81 ndash80 ndash79 ndash78 ndash77 ndash76ndash85Mean signal strength (dBm)
BODEN
(b)
Figure 11 Impact on of roadspopulation in Telia (a) Residence area (b) Roads
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Suburban
Urban
Rest of thearea
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
0
02
04
06
08
1
CDF
of p
opul
atio
n
Figure 12 Signal strength in urban suburban and rest of the areas
10 Mobile Information Systems
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
than 15) of residential area is not covered However onanalyzing signal strength on roads in Figure 11(b) a declinein signal strength is observed Although majority of mu-nicipalities get most of their roads under coverage area thereare municipalities like Overtornea where considerablefractions of roads are not covered
45 Signal Strength inUrban Suburban andRest of theArease effect of signal strength to users in residential areas inurban suburban and rest of the areas is reported in Fig-ure 12e term rest of the areas is used to denote residentialareas that do not fall under urban or suburban category eCDF of population is plotted against GSM signal strengthWhile GSM offers best signal strength in urban areas themedium and least signal strengths are observed in suburban
areas and rest of the areas respectively A fraction ofpopulation is under no coverage area of Tele2 and Telenor insuburban areas and rest of the areas However despite theregion classification Telia offers 1ndash4 dB better signal tousers It is also important to note that the results in Figure 12are based only on the available data We have not consideredareas without measurements for analysis
46 ComparisonwithAnother County GSM signal strengthsof two different counties in Sweden Norrbotten andOstergotland are compared in Figure 13 We compare thesignal strengths observed in urban and suburban areas ofboth counties From Figure 13(a) it is clear that despite ofthe county the signal strength in urban areas remains thesame However from 13(b) it can be observed that the user
02 0 276
1711
3728
2718
753051 0 0 0
743
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(a)
0 0 078
89
26813121
1816
3530 0 0
106
0
25
50
o
f roa
ds
ndash100
- ndash9
0
ndash130
- ndash1
20
ndash50
- ndash40
ndash60
- ndash50
ndash140
- ndash1
30
ndash90
- ndash80
ndash80
- ndash70
ndash70
- ndash60
No
data
No
signa
l
ndash120
- ndash1
10
ndash110
- ndash1
00
Signal strength (dBm)
(b)
Figure 9 LTE coverage on roads (a) Coverage on roads of Lulea (b) Coverage on roads of Pajala
Telia
0 0 1411131
3518 3448
1152025 009 0
5750
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
Tele2
0
3268
1631 152058
531 436 0 0 0576
0
25
C
ars times
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Telenor
01032 1448
24813089
867 5080 0 0
5760
25
C
arstimes
100
m
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
Dat
a
ndash140
ndash ndash
130
Signal strength (dBm)
(a)
Telia
0 0 1321196
3713 3348
991027 01 0 583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0
Tele2
0
3458
1722 155 1947
498 242 0 0 0583
0
25
C
ars times
s
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash60
ndash ndash5
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash90
ndash ndash8
0Telenor
01069 152
24863132
896314 0 0 0
5830
25
C
ars times
s
ndash60
ndash ndash5
0
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash50
ndash ndash4
0
No
Dat
a
ndash100
ndash ndash
90
ndash130
ndash ndash
120
ndash90
ndash ndash8
0
ndash140
ndash ndash
130
Signal strength (dBm)
(b)
Figure 10 Effect of traffic pattern (a) Carstimes 100m (b) Carstimes sec
Mobile Information Systems 9
ARJEPLOG
ARVIDSJAUR
BODEN
GAumlLLIVARE
HAPARANDA
JOKKMOKKKALIX
KIRUNALULEAring PAJALA
PITEAringAumlLVSBYNOumlVERKALIX
OumlVERTORNEAring
0
05
1
15
p
opul
atio
n w
ith n
o sig
nal
ndash75 ndash74 ndash73 ndash72 ndash71 ndash70ndash76Mean signal strength (dBm)
(a)
ARJEPLOG
ARVIDSJAURGAumlLLIVARE
HAPARANDA JOKKMOKK
KALIX
KIRUNALULEAring
PAJALA
PITEAringAumlLVSBYN
OumlVERKALIX
OumlVERTORNEAring
0
1
2
3
4
5
6
7
ro
ad w
ith n
o sig
nal
ndash84 ndash83 ndash82 ndash81 ndash80 ndash79 ndash78 ndash77 ndash76ndash85Mean signal strength (dBm)
BODEN
(b)
Figure 11 Impact on of roadspopulation in Telia (a) Residence area (b) Roads
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Suburban
Urban
Rest of thearea
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
0
02
04
06
08
1
CDF
of p
opul
atio
n
Figure 12 Signal strength in urban suburban and rest of the areas
10 Mobile Information Systems
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
ARJEPLOG
ARVIDSJAUR
BODEN
GAumlLLIVARE
HAPARANDA
JOKKMOKKKALIX
KIRUNALULEAring PAJALA
PITEAringAumlLVSBYNOumlVERKALIX
OumlVERTORNEAring
0
05
1
15
p
opul
atio
n w
ith n
o sig
nal
ndash75 ndash74 ndash73 ndash72 ndash71 ndash70ndash76Mean signal strength (dBm)
(a)
ARJEPLOG
ARVIDSJAURGAumlLLIVARE
HAPARANDA JOKKMOKK
KALIX
KIRUNALULEAring
PAJALA
PITEAringAumlLVSBYN
OumlVERKALIX
OumlVERTORNEAring
0
1
2
3
4
5
6
7
ro
ad w
ith n
o sig
nal
ndash84 ndash83 ndash82 ndash81 ndash80 ndash79 ndash78 ndash77 ndash76ndash85Mean signal strength (dBm)
BODEN
(b)
Figure 11 Impact on of roadspopulation in Telia (a) Residence area (b) Roads
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Telia 2GTele2 2GTelenor 2G
Suburban
Urban
Rest of thearea
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
0
02
04
06
08
1
CDF
of p
opul
atio
n
Figure 12 Signal strength in urban suburban and rest of the areas
10 Mobile Information Systems
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
gets 5 to 10 dB signal strength reduction when the usermoves from urban to suburban area
47 Effect of Roaming It is observed that some areas nearFinland are not getting service by Tele2 and Telenor
Although these areas are in Sweden Tele2 and Telenorswitch the call to another operator from Finland forminglarge areas without measurements from Tele2 and TelenorTelia on the other hand offers connectivity from SwedenFigure 14 shows the histogram of 3G signal strength in roadsof Overtornea It is seen that 70 of roads and 602 of
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1CD
F of
use
r pop
ulat
ion
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(a)
Telia NorrbottenTele2 NorrbottenTelenor Norrbotten
Telia OstergotlandTele2 OstergotlandTelenor Ostergotland
0
02
04
06
08
1
CDF
of p
opul
atio
n
ndash100 ndash90 ndash80 ndash70 ndash60 ndash50ndash110Signal strength (dBm)
(b)
Figure 13 Coverage in Norrbotten and Ostergotland (a) Ostergotland (urban) (b) Norrbotten (suburban)
Telia 3G over OumlVERTORNEAring
85 0 0 39
37225 189
14 04 0 0 730
25
50
75
100
o
f roa
ds
ndash120
ndash ndash
110
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
ndash70
ndash ndash6
0
ndash80
ndash ndash7
0
ndash90
ndash ndash8
0
No
data
No
signa
l
ndash110
ndash ndash
100
ndash130
ndash ndash
120
ndash140
ndash ndash
130
ndash100
ndash ndash
90
Tele2 3G over OumlVERTORNEAring
1090 0 17 38 66 62 08 0 0 0
70
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Telenor 3G over OumlVERTORNEAring
241
0 0 34 53 37 25 09 0 0 0
602
0
25
50
75
100
o
f roa
ds
ndash140
ndash ndash
130
ndash130
ndash ndash
120
ndash120
ndash ndash
110
ndash110
ndash ndash
100
ndash100
ndash ndash
90
ndash90
ndash ndash8
0
ndash80
ndash ndash7
0
ndash70
ndash ndash6
0
ndash60
ndash ndash5
0
ndash50
ndash ndash4
0
No
data
No
signa
l
Signal strength (dBm)
Figure 14 Histogram of 3G signal strength in roads of Overtornea
Mobile Information Systems 11
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
roads from Tele2 and Telenor are under rdquoNo Datardquo bin isis because there is no measurement from Tele2 and Telenorinmajority of roads and Tele2 and Telenor transfer the call toElisa a Finnish operator
48 Correlation with 700MHz Spectrumrsquos Focus AreasRecently 700MHz spectrum has been allocated to certainareas of focus [6] Figure 15 presents the correlation ofTeliarsquos coverage map developed using algorithm pre-sented in Figure 2 and focus areas of new 700MHzspectrum represented by rectangles Different coloursare assigned to each of the locations based on the signalquality from level 1 which is the best to level 14 which isthe worst A major portion of the focus area does notintersect with our map due to lack of measurements andis shown in dashed lines On comparing the focus areasprovided with our coverage map we found that 441 ofthe areas that are intersected with our map experiencepoor signal (below level 10) Around 547 of areas that
are intersected with our map experience below-averagesignal (level 8ndash9)
5 Conclusions
is paper has presented a framework for analyzing mobilesignal strength experienced by users Based on measuredsignal strength a coverage map has been made via IDWinterpolation Various analyses are carried out on signalstrength over residential areas and roads of NorrbottenFurther measurements are compared to those ofOstergotland and it was found that both municipalities havealmost similar measurements
By analyzing coverage across all 14 municipalities ofNorrbotten in contrast to the suspicion that rural areas havepoor signal strength we found that 2G and 4G providesatisfactory results However 3G fails to provide coverage insome areas is is worse in some areas resulting in morethan 50 of areas to be outside coverage area at some placesese areas aremostly near the Finland border which results
Level mapping1 Best2345
678910
8 8 8
8 8 8 8 8 8
8 8 8 8 8 8 8 8
8 8 8 8 8 8 8 8
9 9 12 12 12 12 12 12
9 9 12 12 12 12 12 12
15
15 15 15
15 1515
9 9 12 12 12 12 12 12 13 13 1313
9 9 12 12 12 12 12 12 13 1313
9 9 12 12 12 12 12 12 1313
9 9 12 12 12 12 12 12
12
12
12 12
1212
1212 12
13
9 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
13 13 13 13 13 13 13 13
1313 13 13 13 13 13 13 13
13 13 13 13 13 13 13
13
11121314 No signal15 No data
Oarjjelijsoarvaacutesj
Figure 15 Correlation with 700MHz spectrumrsquos focus area map
12 Mobile Information Systems
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13
in the fact that roaming and additional charges may beapplicable to the 3G user in these areas
Data Availability
e cellular coverage data used to support the findings ofthis study have not been made available yet as commercialinterests of the supplier prevent this
Conflicts of Interest
e authors declare that they have no conflicts of interest
Acknowledgments
e authors gratefully acknowledge the financial support forthis work from the Norrbotten County Council along withthe relentless efforts from Johanna Lindberg without whosesupport this paper would have not been writtene authorsalso thank here the people involved in the project full-tackning with financial support by Vinnova NorrbottenCounty Council and Vasterbotten County Council
References
[1] H Zhang N Liu X Chu K Long A-H Aghvami andV C M Leung ldquoNetwork slicing based 5G and future mobilenetworks mobility resource management and challengesrdquoIEEE Communications Magazine vol 55 no 8 pp 138ndash1452017
[2] ldquoTelia Company and Lule A University of Technology In-augurate 5G-Testbedrdquo 2019 httpswwwteliacompanycomennewsnews-articles20195g-testbed-lulea
[3] H D Gadi R V Murthy R Shanker and V NagadevaraldquoAntennae location methodology for a telecom operator inIndiardquo in IIM Bangalore Research Paper 454 2014
[4] J van de Beek ldquoMobile broadband access in Norrbottenrdquo2019 httpswwwnorrbottensepublikalgregioDigitaliseringmobile-broadband-access-in-norrbotten-KLAR-NYpdf
[5] S A Hadiwardoyo C T Calafate J-C Cano et al ldquoreedimensional uav positioning for dynamic uav-to-car com-municationsrdquo Sensors vol 20 no 2 p 356 2020
[6] ldquoAssignment decision to use radio transmitters in the 700MHz bandrdquo 2019 httpsptssesvdokumentbeslutradio2018tilldelningsbeslut-tillstand-att-anvanda-radiosandare-i-700-mhz-bandet---telia-sverige-ab
[7] P Koutroumpis and A Leiponen ldquoCrowdsourcing mobilecoveragerdquo Telecommunications Policy vol 40 no 6pp 532ndash544 2016
[8] D Baltrunas E Ahmed and A Kvalbein ldquoMeasuring thereliability of mobile broadband networksrdquo in Proceedings ofthe 2014 Conference on Internet Measurement Conferencepp 45ndash58 ACM Vancouver Canada November 2014
[9] J Ponce-Rojas S Vidal-Beltran M A Acevedo-Mosquedaand M Jimenez-Licea ldquoA geographic information systemapplied to coverage maps of 3g cellular communicationsnetworksrdquo Journal of Geographic Information System vol 03no 2 p 140 2011
[10] A Lutu Y R Siwakoti O Alay D Baltrunas andA Elmokashfi ldquoe good the bad and the implications ofprofiling mobile broadband coveragerdquo Computer Networksvol 107 pp 76ndash93 2016
[11] X Chen H Wu and T M Tri ldquoField strength prediction ofmobile communication network based on GISrdquo Geo-SpatialInformation Science vol 15 no 3 pp 199ndash206 2012
[12] L Sheynblat and T Wrappe ldquoMethod and apparatus fordetermining location of a base station using a plurality ofmobile stations in a wireless mobile networkrdquo US Patent7319878 2008
[13] W Riley R Girerd and Z Biacs ldquoUse of mobile stations fordetermination of base station location parameters in a wirelessmobile communication systemrdquo US Patent 7127257 2006
[14] H Wang S Xie K Li and M Ahmad ldquoBig data-drivencellular information detection and coverage identificationrdquoSensors vol 19 no 4 p 937 2019
[15] Z Zhou M Zhang Y Wang C Wang and M Ma ldquoAp-plication of Kriging algorithm based on ACFPSO in geo-magnetic data interpolationrdquo Mathematical Problems inEngineering vol 2019 Article ID 1574918 14 pages 2019
[16] M Molinari M-R Fida M K Marina and A PescapeldquoSpatial interpolation based cellular coverage prediction withcrowdsourced measurementsrdquo in Proceedings of the 2015ACM SIGCOMM Workshop on Crowdsourcing and Crowd-sharing of Big (Internet) Data pp 33ndash38 ACM London UKAugust 2015
[17] Z El-friakh A Voicu S Shabani L Simic and P MahonenldquoCrowdsourced indoor wi-fi REMs does the spatial inter-polation method matterrdquo in Proceedings of the 2018 IEEEInternational Symposium on Dynamic Spectrum Access Net-works (DySPAN) pp 1ndash10 IEEE Seoul South Korea October2018
[18] W Tobler ldquoMeasuring spatial resolutionrdquo in Proceedings ofthe International Workshop on Geographic Information Sys-tems vol 48 International Geographic Union Commissionon Geographical Information Beijing China 1987
[19] ldquoTotal Befolkning Per Rutardquo 2016 httpswwwscbsehitta-statistikregional-statistik-och-kartorgeodataoppna-geodatatotal-befolkning-per-ruta
[20] ldquoNorrbotten Trafikdatardquo 2017 httpswwwtrafikverketselastkajen
[21] ldquoMobile signal strength recommendationsrdquo 2018 httpswikiteltonikaltviewMobile_Signal_Strength_Recommendations
[22] E Leonard R Rainbow J Trindall et al Accelerating Pre-cision Agriculture to Decision Agriculture Enabling DigitalAgriculture in Australia Cotton Research and DevelopmentCorporation Narrabri Australia 2017
[23] ldquoElectronics communication committee reportrdquo 2016 httpsdocdbceptorgdownload494da92a-263aECCRep256pdf
Mobile Information Systems 13