Session6 Deployment Scenarios HSPA WiMAX[1]

Deployment Scenarios Deployment Scenarios

(LTE, HSPA + (LTE, HSPA + WiMAXWiMAX))

ITU/BDT Arab Regional Workshop on “Wireless

Broadband Internet Access in Rural Areas”

Damascus

October 10-12 2010

Sami Tabbane

Cellular Cellular

networks networks

2

networks networks

fundamentalsfundamentals

Cellular network fundamentalsCellular network fundamentals

3

• Main issue: How accommodate the maximum number of

mobile subscribers with a limited resource of bad quality

and out of control?

4 4 propagation basic phenomenaspropagation basic phenomenas

DiffractionDiffraction

4

Réflexion Réfraction

DiffusionScattering

ReflectionRefraction

3D Rayleigh environment3D Rayleigh environment

5

Cellular architectureCellular architecture

• Frequency reuse:

- More capacity,

- More coverage.C

I1 f1

f1

.. < > ^ ... . . .

6

.. < > ^ ... . . .

.. < > ^ ... . . .

.. < > ^ ... . . .

. . .

I2

I3

f1

f1

Multiple access methodsMultiple access methods

• FDMA and TDMA: Concentration of the interference on

some channels.f

.

.

.

fi

f

t f1

.

.

.

fj

1 2 3 4 5 6 1 2 3 4 5

Intervalle de temps ou time slot Time slot

7

• CDMA: interference is

spread over all the channels.

Fréquences

Temps

Codes/Puissance

t

f1 t 1 2 3 4 5 6 1 2 3 4 5

Trame TDMA

Power/Code

Time

Frequencies

Reuse cluster: TDMA/FDMA and Reuse cluster: TDMA/FDMA and

CDMACDMA

frequencyfrequencyfrequencyfrequency

8TDMATDMA DSDS--CDMACDMA

CDMA reuse cluster: multiple CDMA reuse cluster: multiple

access interferenceaccess interference

DownlinkDownlink

9TDMATDMA DSDS--CDMACDMA

1. UMTS main 1. UMTS main

proceduresprocedures

10

proceduresprocedures

UMTS Radio Functionalities (1)UMTS Radio Functionalities (1)

� The UE scans all RF channels in

WCDMA and searches for the

strongest cell signal on each

carrier.

2. Manual mode

1.

2.

Idle mode: PLMN selection

carrier.

� The UE displays those PLMNs

that are allowed as well as those

that are not allowed based on the

strongest signal cell on each

frequency.

� The user can select a PLMN

manually from the list

3.

1.

f1

f2

•

•

fn

Strongest cell

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8x 107

-40

-20

0

20

40

60

80

Frequency

Po

wer

Sp

ect

rum

Mag

nitu

de (

dB

)

PLMN APLMN BPLMN DPLMN E

11

Initiate Cell Synchronization

P-CCPCH

(PSC + SSC + BCH)

UE monitors Primary SCH code, detects peak in matched filter output

Idle mode: search process


Slot Synchronization Determined ------>

UE monitors Secondary SCH code, detects SCG and frame start time offset

Frame Synchronization and Code Group Determined ------>

UE determines Scrambling Code by correlating all possible codes in group

Scrambling Code Determined ------>

UE monitors and decodes BCH data

BCH data, Super-frame synchronization determined ------>

UE adjusts transmit timing to match timing of BS + 1.5 Chips

Cell Synchronization complete

Idle mode behavior: Cell search procedure12

Squal = Qqualmeas- qQualMin > 0

Srxlev = Qrxlevmeas – qRxLevMin – Pcompensation > 0

Where Pcompensation = max(maxTxPowerul – P;0)

Cell selection process


� qQualmin: sent in the broadcast information and indicates the

minimum required quality value. The UE measures the received

quality, “Qqualmeas”; on the CPICH (CPICH Ec/N0) and

calculates Squal.

� qRxLevMin: sent in the system information and indicates the

minimum required signal strength. The UE measures the received

signal Code Power (CPICH RSCP) and obtains Srxlev

13

� maxTxPowerful: the maximum transmission power during

random access on the RACH. Value sent in the system

information.

� P: the UE maximum output power according to its class

Cell selection process


• Qqualmeas

• Qrxlevmeas P-CCPCH

CPICH

• qQualmin

• qRxLevMin

• maxPowerul

Idle mode behavior: Cell selection process 14

In order to always camp on the best cell the UE performs the cell

reselection procedure in the following cases:

� When the cell on which it is camping is no longer suitable.

� When the UE, in “camped normally” state, has found a better

Cell reselection process


S q u a l > 0 (o n ly W C D M A ce lls )

S rx le v > 0

� When the UE, in “camped normally” state, has found a better

neighboring cell than the cell on which it is camping.

� When the UE is in limited service state on an acceptable cell.

When the UE triggers a cell reselection evaluation process, it

performs ranking of cells that fulfill the following criteria:

15

Cells are ranked according to the R criteria:

R(serving) =Qmeas(s) + qHyst(s)

R(neighbor) = Qmeas(n) - qoffset(s,n)



�Qmeas is the quality value of the received signal.

�Qmeas may be derived from the averaged CPICH Ec/No or

CPICH RSCP for WCDMA cells.

�Qmeas uses the averaged received signal level for GSM cells.

CPICH RSCP is always used as a measurement quantity when

WCDMA cells are compared with GSM cells. 16

Qmeas(n)qHyst(s)

R(n)

Quality



Qmeas(s)

qoffset(s) R(s)

R(n)

treSelection

Cell reselection

time

Idle mode behavior: Cell reselection procedure

17

� Cell reselection criteria are used for intra-frequency, inter-frequency

and inter-RAT cells.

� Decision on when measurements on intra-frequencies should be

performed is made using the parameter sIntraSearch in relation to



performed is made using the parameter sIntraSearch in relation to

Squal.

If Squal > sIntraSearch the UE does not need to perform

intrafrequency measurements.

If Squal ≤ sIntraSearch the UE performs intrafrequencymeasurements.

If the sIntraSearch is not sent to the serving cell, the UE

performs intrafrequency measurements.

18

RRM algorithms implementationRRM algorithms implementation

UEUE

19

- Power control

- Quality measurements

- Measurement report

- Packet scheduling

- Load control

- Fast power control

- Rate adaptation

- H-ARQ, MIMO

- Admission control

- Load control

- HO control

- Outer loop power

control

UEUE Node BNode B RNCRNC

From the UE point of view, the WCDMA cells are divided into Active,

Monitored, and Detected Sets.

i. The Active Set: The radio links involved in the handover

ii. The Monitored Set: The neighbors of the Active Set cells, are

Softer Handover process


explicitly measured for handover (can contain both intra-frequency

and GSM neighboring cells).

iii. The Detected Set: The UE is also required to detect intra-frequency

cells that are not in the Active or Monitored Sets

� The active set size is configured by operator using

“maxActiveSet” parameter (from 2 � 4 cells) 20

Parameters and constraintsParameters and constraints

• Parameters:

– CDMA technology with new engineering

rules,

– Deployment strategy with existing 2G and

21

– Deployment strategy with existing 2G and

2,5 G networks.

• Radio constraints:

– Services segmentation and related QoS,

– Coverage/services tradeoff.

CDMA planning principlesCDMA planning principles• Issues:

- Band shared among all active connections � Separation

between Radio planning – Dimensioning not possible,

- Coverage and capacity are linked together,

- The capacity depends on the traffic distribution and the

base stations location.

22

base stations location.

CDMA advantages:

- no a-priori limitation of the capacity as in TDMA �

Soft capacity,

- capacity allocation done according to C/I (bandwidth

allocation if SIRmin ≤ SIR).

WCDMA systems specificities (1)WCDMA systems specificities (1)• Main features and constraints:

− Node B power: shared among the N connected mobiles,

− Noise maximum power: 10 dB,

− Transmission power: between 6 and 10 dB,

− Transmission power on each level: depends on propagationconditions and activated service,

− Mobiles distribution in the cell: if the mobiles are close to the

23

− Mobiles distribution in the cell: if the mobiles are close to theNode B, capacity can be up to 10 times that of when the mobileare far from the Node B,

− Cell breathing: access management achieved by call admissioncontrol based on the noise rise and load control,

− Power control is fundamental for the UL: outer loop to adjust the target power according to the BER estimation and fast power control against fast fading. Fast power control � continuoustransmission on the radio interface, packet transmission at layer 2.

Relation between power and service bitrate

Pr

Voice service

Pr

Pe

Power

level of the

Power transmitted by

the Node B

WCDMA systems specificities (2)WCDMA systems specificities (2)

24

Pr

Email service

PrVideo service

level of the

signals

received by

the mobiles

3. UMTS networks 3. UMTS networks

planning planning processprocess

25

planning planning processprocess

UMTS planning processUMTS planning processMultiservice

offered traffic

Traffic analysis

Required channel number for the

26

WCDMA link budget

Cell number

Required channel number for the

considered configuration

Maximum cell range

Number of carriers per cell

Nominal PlanningNominal PlanningNominal PlanningNominal Planning� Based on the result of network dimension, preliminary design

present Information of theoretical sites including following:

� Site coordinates.

� Engineering parameters such as Antenna height, azimuths and tilts.

� Radio parameters such as scrambling code ,transmit power of

different channels , etc.different channels , etc.

27

• Simulation

– Unlike GSM network, in CDMA coverage and capacity are too inter-

related to be predicted accurately. Monte Carlo simulation is used to

evaluate the performance of a radio network.

WCDMA simulationWCDMA simulation

– Monte Carlo is a static simulation

During Monte Carlo simulation, the performance of the network is analyzed over

various instances in time (snapshot), where UEs are in statistically determined

places with the given traffic model. The ability of each terminal to make its

connection to the network is calculated through an iterative process.

Setup Setup

networknetwork

DesignDesign

Run PilotRun Pilot

Field Field

StrengthStrength

PredictionPrediction

PilotPilot

LevelLevel

OK?OK?

RNP Input & RNP Input &

EquipmentEquipment

configurationconfiguration

YESYES

NONO

Traffic model Traffic model

& forecast& forecast

Simulation flowSimulation flow--chartchart

Run Run

UMTSUMTS

TrafficTraffic

simulationsimulation

Make predictionsMake predictions

(Services)(Services)

PerformancePerformance

RequirementsRequirements

Fulfilled?Fulfilled?

Neighbors Neighbors

planning&planning&

Scrambling code Scrambling code

allocationallocation

Neighborhood Neighborhood

planning criteriaplanning criteria

Scrambling code Scrambling code

allocation criteriaallocation criteria

OutputOutput

parametersparameters

YESYES

NONO

29

Simulation outputSimulation output

• Simulation output：– Pilot coverage (Ec, Ec/Io) in the

target areas

– Best server plot

– Coverage probability distribution of each service

– Access failure distribution and – Access failure distribution and statistic of each service

– Continuous coverage areas of each service

– Cell load distribution of downlink and uplink

– Pilot pollution distribution

– Soft handover areas statistic of each service

• For each theoretical site, a physical site will be acquired in this phase

through following steps:

Define search areas

Site ranking

Identify candidate sites

Site SurveySite Survey

A3rd

D1st

Site ranking

Site acquisition

� A suitable physical site

� Give adequate radio coverage.

� Have connectivity into the transmission network.

� Be politically acceptable to the local community.

� Have power nearby, good access and a co-operative owner.

C2nd B - Unsuitable

31

Verification by system simulationVerification by system simulation

• It is an iterative process to

verify the final design until all

the requirements are fulfilled

Coverage predictionCoverage prediction

RNP

Planning

results

Are requirements

Fulfilled?

Traffic distributionSystem simulation

32

4. CDMA link 4. CDMA link

budgetbudget

33

budgetbudget

Link budgetLink budget

First dimensioning realized according to

the coverage: compute cell size for the

most constraining services.

- Uplink: MAPL, cell size determination,

34

- Uplink: MAPL, cell size determination,

- Downlink: Link budget balancing to

determine the BS power. BS power shared

by all the channels (common and traffic).

Link Budget parameters (1)Link Budget parameters (1)

Load factor and noise rise

• Noise rise level of noise increase due to the increase

of the load in the cell.

Noise rise is related to the load factor which measures

the load of each link (uplink or downlink).

35

the load of each link (uplink or downlink).

� Noise rise is important if the capacity and this the load

authorized in the cell is important (then reduced cell

size).

�Urban areas: large noise rise,

� Rural areas: reduced noise rise.

The more the noise rise, the smaller the cell radius but the higher the potential traffic carried in the cell.

� Noise Rise = Traffic Margin.


Wideband interference

Narrowband interferenceUplink channel loading

Downlink channel interference

Coverage

and

capacity

36

NoiseDownlink channel interference capacity

Noise Rise

Capacity

Lp (dB) = Pt (dBm) + Gt (dBi) – Pr (dBm) + Gr (dBi)

= EIRP (dBm) – Pr (dBm) + Gr (dBi)

EIRP depends on the UL or DL.

UL/DL link budgetUL/DL link budget

Uplink (UL) Downlink (DL)

EIRP (dBm) = EIRP (dBm) =

37

PTx (dBm) – Lu (dB) + Gt (dBi) PTx (dBm) – Lc (dB) + Gt (dBi)

PTx: transmission power,

Gt: antenna gain,

Lu: body loss (voice: [3, 10],

data: [0, 3]).

PTx: transmission power,

Gt: antenna gain,

Lc: feeder losses.

Noise rise versus number of subscribers per cell


6

8

10

12

No

ise

Ris

e (d

B)

38

0

2

4

6

0 10 20 30 40 50 60

Nombre d'abonnés / cellule

No

ise

Ris

e (d

B)

Number of subscribers per cell

UL power budget (example for 144 kb/s data service)UL power budget (example for 144 kb/s data service)

Value Formula

Transmitter

P: MS Tx Power (dBm) 23

MAG: MS Tx Antenna Gain (dBi) 0

BL: Body Loss (dB) 3

PIRE: MS EIRP (dBm) 20 EIRP= P+MAG-BL

Receiver

FM: Fade Margin (dB) 5,4 FM = 0,675*SD (RC=90%, SD=8dB)

39


IM: Interference Margin (dB) 3 IM = 10log(1/1-loading)

PL: Pathloss (dB) 0 Dense Urban = 20 dB

BAG: BTS Antenna Gain (dBi) 16

BCL: BTS Cable Loss (dB) 3

SHG: Soft HO Gain (dB) 2

TM: Total Margin (dB) -6,6 TM=FM+IM+PL-BAG+BCL-SHG

S: BTS Rx Sensitivity (dBm) -115

UL_PL: UpLink Path Loss (dB) 141,6 UP_PL = EIRP-TM-S

DL DL linklink budgetbudgetValue Formula

Transmitter

P: BTS Tx Power (dBm) 29 Power allocated to the pilot channel

BAG: BTS Tx Antenna Gain (dBi) 16

BCL: BTS Cable Loss (dB) 3

PIRE: BTS EIRP (dBm) 42 PIRE = P+BAG-BCL

Receiver


40


IM: Interference Margin (dB) 3 IM = 10log(1/1-loading)

PL: penetration loss (dB) 0 Dense urban = 20 dB

MAG: MS Antenna Gain (dBi) 0

SHG: Soft HO Gain (dB) 2

TM: Total Margin (dB) 9,4 TM=FM+IM+PL-MAG+BL-SHG

S: MS Rx Sensitivity (dBm) -110

DL_PL: DownLink Path Loss (dB) 142,6 UP_PL = PIRE-TM-S

5. 5. LoadLoad factor and factor and

noise noise riserise

41

noise noise riserise

Uplink: Mpole

Pole capacityPole capacity

Uplink limited capacity: uplink Mpole values

42

Uplink: Noise Rise

Uplink interference degrade the RBS sensitivity with a

margin of BIUL ,calculated as following

Noise riseNoise rise

Where Q is the system load: Q = + +M1

Mpole

M2

Mpole

Mn

Mpole

M1,…. Mn are the number of users on services 1 … n

43

Uplink: Noise RiseUplink: Noise Rise

RB

S S

ensitiv

ity

System load (Q)

100 %

44

Downlink: MDownlink: Mpolepole

γ: Downlink C/I targetγ: Downlink C/I target

ε: C/I compensation term for fast fading

α: Non orthogonality factor

nAS: Typical size set

b: Number of active links

κ: Fraction of user in soft/softer handover

GSHO: Soft HO gain

GDTX: DTX gain 45

Downlink: MDownlink: Mpolepole

Downlink limited capacity: Downlink Mpole values

46

Noise RiseNoise Rise• Noise Rise = - 10log10(1 – nul).

• Value used as interference margin in the calculation of the link budget. Increases with transmission bitrate and the number of communications.

�Capacity of the system defined by the pole capacity. Corresponds to the case where nul reaches1.

47

Corresponds to the case where nul reaches1.

�Pole capacity never reached as it assumes infinite mobile transmission powers.

� In practice: Maximum WCDMA cell load between 40 and 70 %.

�Example: Load between 20 and 50 % � noise rise = 2 dB.

Downlink: Noise RiseDownlink: Noise Rise

Downlink interference degrade the UE sensitivity

with a margin of BIDL ,calculated as following ;

Where

� Lsa = Lpmax + Bpc + BLNF + LBL + LBPL + Lj – Ga

� Nt: thermal noise power density (-174 dbm/Hz)

� Nf: Noise figure

Where

48

Cell breathingCell breathing

RBS

Q = Qmax = 60 %

Q = 0 % (no traffic)

Cell breathing phenomena

RBS

49

Cell breathing phenomenaCell breathing phenomena

50

Case 1 : 10 users Case 2 : 20 users

-10 < C/I < -5 dB -15 < C/I < -10 dB

-15 < C/I < -50 dB cells

Capacity, cell radius and Capacity, cell radius and noise risenoise rise

R

Charge de la cellule = 20 % de

la capacité maximum

Niveau d’interférence = y dB

R et R’ sont les rayons des

Cell load = 20% of the

maximum capacity

Interference level = y dB

R and R’: cell

radiuses in the 2 load

51

R

R’

Charge de la cellule = 50 % de

la capacité maximum

Noise Rise = 2 dB

Niveau d’interférence = y + 2 dB

R

R et R’ sont les rayons des

cellu les dans les deux

situations de charge

radiuses in the 2 load

conditions

Cell load = 50% of the

maximum capacity

Interference level = y + 2 dB

6. Coverage and 6. Coverage and

servicesservices

52

servicesservices

Coverage and services (1) Coverage and services (1) Link budget Service throughput

Relation between coverage and service throughput

53Yellow = 12.2 kbps – Orange = 64 kbps - Red= 384 kbps

Coverage and services (2) Coverage and services (2)

54Blue = 144 kbps – Red = 384 kbps

Traffic location and BS capacityTraffic location and BS capacity

< >^

...

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...

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..

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...

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55

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..

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...

. ..

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. ..

..

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...

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..

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..

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...

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Benefits for locating the sites close to Benefits for locating the sites close to hot spotshot spots

− Minimises the power on downlink channels;

− Reduction in the number of mobiles in softhandover and increase in the BS averagecapacity;

− Reduction of the interference on the uplink;

− Increase of BS capacity: terminals close to the

56

− Increase of BS capacity: terminals close to theBS require less power and thus minimise the DLinterference. Furthermore, mobiles connected toneighbour base stations de base being far fromcurrent one, inter-cell interference is low, andthus increasing the capacity of the neighbour BSon the UL.

Coverage/capacity versus distance (2)Coverage/capacity versus distance (2)

57

HSDPA capacity limitsHSDPA capacity limits

58

2. OFDMA 2. OFDMA

planning (LTE planning (LTE

59

planning (LTE planning (LTE

and and WiMAXWiMAX))

OFDM planning OFDM planning principlesprinciples

• Main principles as FDMA/TDMA

• Evaluate the propagation constraints

• Estimate the traffic potential• Estimate the traffic potential

• Combine coverage and traffic

capacities with 2G/3G existing ones

60

PrinciplePrincipleTypes of equipments Environment

Subscribers distribution

Choice of the most robust profile

System capacity

Link budget

Traffic model

Prediction margin

Propagation model

Propagation environmentmargin environment

Max(BS1, BS2)

Estimated cost

Number: BS1 Number: BS2

Economic profitability?No

yes61

OperatorOperator SLASLA

– Scheduling QoS

– Logical Data Pipe

– Protocol Overhead Factor

– COT/MSTR– COT/MSTR

– Additional QoS

– f(LF*OSR, MSTR)

– Maximum Sustained Traffic Rate (MSTR)

– Load Factor per Customer (calculated or user input)

– Over-Subscription Ratio (OSR)

– Data Delay Distribution (Latency)62

Configuration of the offered QoSConfiguration of the offered QoS

63

Example of service configurationExample of service configuration

• If the used

traffic user is

not knows, the

load factor is

defined by the

operator64

Services Services exampleexample

VoIP (downlink/uplink)

1. Consumer UGS 32K/32K

2. SME UGS 64K/64K

MSTR (downlink/uplink)

1. Consumer nrtPS 64K/64K1. Consumer nrtPS 64K/64K

2. Consumer ertPS 256K/256K

3. Consumer nrtPS 512K/128K

4. Consumer nrtPS 1M/256K

5. SME rtPS 512K/512K 6. SME nrtPS 1M/256K

7. SME nrtPS 2M/512K 8. VPN ertPS 512K/512K

9. VPN ertPS 1M/1M 10. VPN ertPS 2M/2M

65

Traffic evolution during the dayTraffic evolution during the day

66

Subscribers distributionSubscribers distribution

67

Radio environment characterisationRadio environment characterisation

68

User terminal characterisationUser terminal characterisation

69

Radio interface configurationRadio interface configuration

70

Propagation model constraintsPropagation model constraints

• Indoor and outdoor prediction together,

• Takes into account the RF canyons (streets, roads,

…),

• Propagation parameters reusable in similar cells

• Average error less than 0,5 dB for calibrated cells • Average error less than 0,5 dB for calibrated cells

calibrees and and less than 2 dB for non

calibrated cells,

• Standard deviation of less than 7 dB for calibrated

cells and less than 9 dB for non calibrated cells.

71

Modulation/Modulation/codingcoding impact (1)impact (1)

72

Modulation/Modulation/codingcoding impact (2)impact (2)

73

BitrateBitrate/coverage relation (1) /coverage relation (1) BPSK: SNR = 6 dB

QPSK: SNR = 6 dB

16-QAM: SNR = 6 dB

64-QAM: SNR = 6 dB

Gross

Modulation Coding

Gross

bitrate

(kb/s)

Sensitivity

(dBm)

Normalized

range

Normalized

area%

QPSK 1/2 D1 S1 R1 Z1 P1

QPSK 3/4 D2 S2 R2 Z2 P2

16-QAM 1/2 D3 S3 R3 Z3 P3

16-QAM 3/4 D4 S4 R4 Z4 P4

64-QAM 2/3 D5 S5 R5 Z5 P5

64-QAM 3/4 D6 S6 1 1 P674

BitrateBitrate/coverage relation (2) /coverage relation (2)

75

Coverage simulation (1)Coverage simulation (1)

• Multi-sector coverage, 3 sectors, 3 carriers, 2,8

b/s/Hz/cell, 22.5Mb/s/sector76

Coverage simulation (2)Coverage simulation (2)

• Multi-sector coverage, 6 sectors, 6 carriers, 2,8

b/s/Hz/cell, 22.5Mb/s/sector77

Traffic modelTraffic modelSubscribers classes Offered services

DL bitrate

(kb/s)

UL bitrate

(kb/s)

Contention

factor

QoS

class

Residential

(basic services)

Web browsing,

Email,

Chatt

128

14

4

80

14

4

20:1

20:1

20:1

BE

BE

BE

Residential

(supplementary

services)

Web browsing,

Email,

VoIP,

Jeux interactifs

256

14

128

85

128

14

128

85

20:1

20:1

4:1

5:1

BE

BE

rtPS

rtPSservices)

Jeux interactifs 85 85 5:1 rtPS

SME

Web browsing,

Email,

FTP

256

14

1000

128

14

0

20:1

20:1

1:1

BE

BE

nrtPS

Large

enterprises

Web browsing,

Email,

FTP,

Videoconference

VPN

512

14

1000

384

2000

128

14

0

384

312

10:1

20:1

1:1

5:1

1:1

BE

BE

nrtPS

rtPS

nrtPS

Note: the contention factor may change during the day 78

DL Dimensioning (1)DL Dimensioning (1)

Highest capacity required on the DL.

traffic per subscriber

TDL/subscriber = Σ DDLi* TCservice* G

TDL/subscriber : mean traffic per subscriber on the

DL (kb/s)

DDLi : mean bitrate for the service i

TCservice : service contention rate

G : Burstiness margin = Dcrête/Dmean

79

DL dimensioning (2)DL dimensioning (2)

Agreggated traffic for the area

DDL = τp * N * Σ τi(TDL/subscriber)i

τ : percentage of class i subscribersτi : percentage of class i subscribers

N : total number of subscribers

DDL : total bitrate for the area on the DL

(TDL/subscriber)i : total bitrate per class i subscriber.

80

Coverage areaCoverage area

Ri � covered area (hypothesis: hexagonal cells)

Z

RZ

QAM

ii

−

≈64

2

2

3.3

81

Hypothesis: users distributed on the differents profiles in the same

proportions as the normalized areas.

Mean gross bitrate per sector:

Dmean/sector = Σ Pi * Di

Pi : percentage users using modulation i

Di : gross bitrate for the modulation i

N : total number of used modulations.

Dimensioning (1)Dimensioning (1)

• Dimensioning for 16-QAM modulation availability in the cell:

• Mean gross bitrate per sector:

• If MAC header represents 10% of the real mean bitrate per

sector:

∑=

=N

iiimoy DPD

3sect/ *

82

DRmean/sect = 0,9*Dmean/sect

• Maximum number of users in the cell:

• Nusers: number users in the cell,

• DRmean/sect: mean capacity per cell (or sector),

• DDL: needs in traffic for the DL.

D

DN

DL

Rmoy

usagersMax

sect/

sect/ =−

Dimensioning (2)Dimensioning (2)

•Total number of sectors required:

Nsectors = Nusers_tot/Nmax-users/sector

•Nsectors: required cells or sectors number,

•Nusers-tot: maximum users number in the service

area,

83

area,

•Nmax-users/sector: maximum number of users per

sector.

•Total number of base stations:

N_BScapacity = Nsectors/Nsectors/BS

DL link budgetDL link budget

84

UL link budgetUL link budget

85

Protection ratiosProtection ratios

ModulationCoding

rate

Co-channel

interference

sensitivity

for BW=3,5

MHz

Adjacent

channel

interference

sensitivity for

BW=3,5 MHz

N+2 adjacent

channel sensitivity

for BW=3,5 MHz

BPSK1/2 4 -30 -46

3/4 6 -28 -443/4 6 -28 -44

QPSK1/2 7 -27 -43

3/4 10 -24 -40

16 QAM1/2 12 -22 -38

3/4 16 -18 -34

64 QAM2/3 21 -13 -29

3/4 22 -12 -2886

Modulation sensitivity for fixed Modulation sensitivity for fixed

WiMAXWiMAX

Modulation Coding Sensitivity (dBm)

Fixed DL gross

bitrate (Mb/s) –

3,5 MHz

Fixed net DL

bitrate (Mb/s) –

3,5 MHz

BPSK

1/2 -100 1,41 1,128

3/4 -98 2,12 1,696

QPSK

1/2 -97 2,82 2,256

3/4 -94 4,23 3,384

16 QAM

1/2 -91 5,54 4,512

3/4 -88 8,87 7,096

64 QAM

2/3 -83 11,29 9,032

3/4 -82 12,71 10,168

87

Coverage and throughput for fixed Coverage and throughput for fixed

WiMAXWiMAX

88

Bitrate and coverage for mobile Bitrate and coverage for mobile WiMAXWiMAX

Modulation CodingSensitivity

(dBm)

Mobile DL bitrate (Mb/s)

– 5 MHz

QPSK 1/8 -101 Below noise level

QPSK 1/2 -94 2,88

16 QAM 1/2 -88 5,58

89

CoverageCoverage and and bitratebitrate for mobile for mobile WiMAXWiMAX

90

Link budget and cell maximum radiusLink budget and cell maximum radiusLink budget � maximum cell radius for a given modulation

Simplified link budget

Power transmitted (dBm) Pe

Feeder cable losss (dB) Le

Antenna gain (dBi) Ge

EIRP(dBm) EIRP= P – Le – Ge

Propagation loss Lp

91

Propagation loss Lp

Penetration loss due to buildings and trees (dB) A1

Other losses (dB) A2

Mean pathloss (dB) Pm = Lp + A1 + A2

Receiving antenna gain Gr

Reception losses (dB) Lr

Receiver effective power Peff = EIRP+ Pm + Gr + Lr

Fading margin 10 dB

Reception sensitivity (modulation/coding) Sr

Margin (modulation) 0

Total capacity in number of cellsTotal capacity in number of cells

• Radius determined per link budget � number of

cells.

• Hypothesis: hexagonal cells .

R

SBSN Zone

couverture 2*6,2_ =

92

• Sarea: area to be covered in km,

• Rmax: maximum cell radius.

• Total BS number:

NBS = Max[N_BScapacity, N_BScoverage]

Rcouverture 2

max*6,2

Frequency reuseFrequency reuse

• High spectrum efficient modulations (64 QAM)

⇒ reuse factor ≥ 6 (6 in NLOS and 3 or 4 in

LOS).

• Less constraints for modulations 16 QAM or• Less constraints for modulations 16 QAM or

QPSK: similar performances for reuse factors <

6 (2 in NLOS).

• For all modulation schemes: lower reuse factors

⇒ fading margin reduction and then lower

ranges or or BER conditions improvement.

93

WiMAX fractional reuse (1)WiMAX fractional reuse (1)

94

• Reuse cluster size =1

• No frequency allocation required

• flexible reconfiguration

FractionnalFractionnal reusereuse cluster in cluster in WiMAXWiMAX

(2)(2)

95

4 sectors reuse cluster4 sectors reuse cluster

4 sectors, 2

carriers with

90° cross-polar

96

90° cross-polar

antennas.

Antennas

height: 30 m.

6 6 sectorssectors reusereuse clustercluster

6 sectors, 3

carriers 60°

cross-polar

antennas.

97

C/I and C/I and reusereuse

factorsfactors

98

FrequencyFrequency

plan 1: N=4, plan 1: N=4,

6060°° sectorssectors, ,

NLOS NLOS NLOS NLOS

conditions conditions

and LOS, 12 and LOS, 12

carrierscarriers

99

Frequency Frequency

plan 2: N=4, plan 2: N=4,

9090°° sectors, sectors,

NLOS NLOS

conditions conditions conditions conditions

and LOS, 8 and LOS, 8

carrierscarriers

100

ConclusionsConclusions

101

ConclusionsConclusions

Planning issues: Planning issues: integratingintegrating

new radio new radio systemssystems

Main drawbacks

CAPEX

- Buy systems separately

-Deploy systems separately

OPEX

- Operate systems separately- Operate systems separately

- Maintain systems separately

Performance

- Bad intersystem

coordination

- High intersystem

interference

Reliability

- Fault point & risk increasing

- Hard for trouble shooting

102

Single RAN solutionSingle RAN solution

Huawei single RAN solution 103

Documents

Session6 Deployment Scenarios HSPA WiMAX[1]