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Features
Version 1.0
20th Oct 2005
List of Features
1. Dynamic Power Control
2. HCSDedicated
Idle
3. Multi Band UL/OL (Single BCCH)
4. Half Rate
5. TCC
IRC
1. BTS Dynamic Power Control
BTS Dynamic Power Control
Introduction:With the Dynamic BTS Power Control feature, the output power of a Base Transceiver Station (BTS) can be controlled to maintain a desired received signal strength and quality in the mobile station (MS) during a connection.
Thus reducing the over all interference level in the network.
General:Dynamic BTS Power Control is performed for Traffic Channels (TCH) as well as for Stand Alone Dedicated Control Channels (SDCCH).
Power control of the SDCCH is enabled with the switch SDCCHREG.
All time slots on the BCCH frequency are transmitted on full power.
Algorithm (I)
Consists of 4 stages
9702718
Preparation ofinput data
Filtering ofmeasure-ments
Calculation of power order
Send power order (REGINTDL)
Every SACCH period
Algorithm (II): Stage 1 – Preparation of input data
At SACCH period k, the output power used by the BTS (TRU) is given by the equation below:
BTS (TRU) output power (k) (dBm) = BSPWRT – 2 * PL used (1)Where PL used = 0-15
All signal strength and quality measurements are compensated before the filtering according to the equations below:
SS_COMP = SS TCH + 2 * PL used (2)
Q_COMP = RxQual (dB) + 2 * PL used (3)
Algorithm (III):Stage 2 – Filtering of measurements
The filtering for both signal strength and quality is done with exponential non-linear filters.
SS FILTERED (k) = b * SS_COMP(k) + a * SS FILTERED (k-1) (4)
If SS_COMP(k) < SS FILTERED (k-1)then L = SSLENDL
else L = SSLENDL * UPDWNRATIO / 100
Algorithm (IV):Stage 2 – Filtering of measurements (cont)
Quality filtering is performed in the same way as for signal strength.
Q FILTERED (k) = b * Q_COMP(k) + a * Q FILTERED (k-1) (5)
If Q_COMP(k) < Q FILTERED (k-1)
then L = QLENDL
else L = QLENDL * UPDWNRATIO / 100
Algorithm (V): Stage 3 – Calculation of power order
The basic power orders for regulation (pu1 and pu2) are given by the following expression:
pui (dB) = ai * (SSDESDL – SS FILTERED ) + bi * (QDESDL_dB - Q FILTERED ) (6)
i = 1, 2Where the parameters ai and bi are defined as follows:
a1 = LCOMPDL / 100 (pathloss compensation)
b1 = QCOMPDL / 100 (quality compensation)
a2 = 0.3 (pathloss compensation, serve as a limitation for regulation close to noise floor)
b2 = 0.4 (quality compensation, serve as a limitation for regulation close to noise floor)
QDESDL [dtqu]
0 10 20 30 40 50 60 70
rxqual 0 1 2 3 4 5 6 7C/ I [dB] 23 19 17 15 13 11 8 4
QDESDL expressed in C/ I is called QDESDL_dB which is the value used in the calculations
Chart (I): Stage 3 – Calculation of power order
Base station output power and MS signal strength versus path loss. Quality is not taken into account.
20 dB regulation with LCOMPDL = 10
SSDESDL = -75
BTS output power versus RxQual. Signal strength is not taken into account.
QDESDL = 30
20 dB regulation with QCOMPDL = 60
20 dB regulation with QCOMPDL = 60
Chart (II): Stage 3 – Calculation of power order
Algorithm (VI): Stage 3 – Calculation of power order (cont)
The resulting power order is called the unconstrained power order, pu.
pu = max(pu1, pu2) (7)
Note:Dynamic power range limitation is applied if the unconstrained power order, pu is outside the dynamic range:The highest allowed power order is zero (0). This corresponds full power according to BSPWRT.The lowest allowed power order is given by maximum of
(a) –30, BSPWRT – (Minimum BTS output power (H/W limit))(b) BSTXPWR – BSPWRMIN.
The power order is then converted to power level PL used representation and transmitted to the BTS:
PL used = Int (-pu/2) [0-15] (8)
Algorithm (VIII):Stage 4 – Send power order
When a power order is sent it takes REGINTDL SACCH periods before the next power order can be sent.
If this power order differs from the previous one, it is sent.
If it does not differ from the previous one, a new order is calculated every SACCH period until a different power order is obtained. Then, that order is sent and REGINTDL SACCH periods must elapse before a new order can be sent again.
List of related Parameters
ParameterCurrent Value Range Unit Brief Discription
SSDESDL -90 -110 to -47 dBm Desired value for RxLev that the regulation will aim in the regulation processQDESDL 30 0 to 70 dtqu Desired value for RxQual that the regulation will aim in the regulation process
LCOMPDL 5 0 to 100 % Pathloss compensationQCOMPDL 55 1 to 100 % Quality compensationREGINTDL 1 1 to 10 SACCH Period Minimum Time Between power ordersSSLENDL 3 3 to 15 SACCH Period Signal strength filter length (averaging)QLENDL 3 1 to 20 SACCH Period Quality filter length (averaging)
SDCCHREG OFF ON, OFF Enables power control on the SDCCHBSPWRMIN -20 -20 to +50 dBm Minimum BTS output power. (ie. 47-20 = 27dBm)BSTXPWR 0 to 80 dBm BTS output power on the TCH frequencies
UPDWNRATIO 200 100 to 700 % Ratio between up and down regulation speedSTEPLIMDL OFF ON, OFF Down regulation can be limited to 2 dB per SACCH
Current/Default Settings
1
11
21
31
41
51
61
01
23
45
67
0
2
4
6
8
10
12
Regulation (dB)
RXLev
RXQual
10-12
8-10
6-8
4-6
2-4
0-2
SSDESDL
QDESDL
LCOMPDL
QCOMPDL
-90
30
5
55
Example of Settings (I)
1
11
21
31
41
51
61
01
23
45
67
0
5
10
15
20
Regulation (dB)
RXLev
RXQual
15-20
10-15
5-10
0-5
SSDESDL
QDESDL
LCOMPDL
QCOMPDL
-90
30
10
55
Example of Settings (II)
1
11
21
31
41
51
61
01
23
45
67
0
5
10
15
20
Regulation (dB)
RXLev
RXQual
15-20
10-15
5-10
0-5
SSDESDL
QDESDL
LCOMPDL
QCOMPDL
-90
30
5
60
Example of Settings (III)
1
11
21
31
41
51
61
01
23
45
67
0
5
10
15
20
25
Regulation (dB)
RXLev
RXQual
20-25
15-20
10-15
5-10
0-5
SSDESDL
QDESDL
LCOMPDL
QCOMPDL
-90
30
10
60
2. HCS - Hierarchical Cell Structure
HCS - Hierarchical Cell Structure Hierarchical Cell Structures (HCS) is a way of displacing the cell borders.
HCS cells can be given priority over stronger cellsHCS provides the required logical function to distribute the traffic between cells HCS Use Up to eight layers (in up to eight bands)
Layer 1 has higher priority than Layer 2, Layer 3, Layer 4, ...Layer 2 has higher priority than Layer 3, Layer 4, Layer 5, ...
The layers can be distributed over the HCS bands in a variety of combinations as long as their order is maintained
Result:Move the handover border from the signal strength border to a new handover border controlled by the band threshold ,i.e, larger service area
Benefits:Fully utilizing the radio capacity, by adjusting the effective cell coverageOffering sufficient quality, smaller cells might provide better quality even is not stronger
HCS - Layer and Band parametersMain Controlling Parameters:
HCSBANDTHR: decides if the cell should be prioritized over stronger cells from other HCS bandsLAYERTHR: decides if the cell should be prioritized over stronger cells in the same HCS band
For each cellLAYERTHR: Signal strength threshold LAYERHYST: Hysteresis
For each bandHCSBANDTHR: Signal strength thresholdHCSBANDHYST: Hysteresis
For serving cell, the band threshold isHCSBANDTHR-HCSBANDHYSTLAYERTHR-LAYERHYST
For neighboring cells, the band threshold is HCSBANDTHR+HCSBANDHYSTLAYERTHR+LAYERHYST
HCS - Algorithm
HCS band evaluation rearranges the candidate list in Locating according to the priority rules
In general, the cells that have met the sufficient signal strength level
(better than band or layer threshold) will be evaluated by HCS ranking
cells in HCS ranking (i.e. prioritized cells) will be placed on top of the list that does not meet HCS criteria (i.e. non-prioritized cells).
Ranking for prioritized cells: the lower the layer, the higher priority & the higher in the ranking
Ranking for non-prioritized cells: based on basic ranking
HCS - AlgorithmBasic ranking list are re-sorted by HCS algorithmMust fulfill the following to be qualified as candidate in HCS band evaluation:
Neighboring cells:SS > HCSBANDTHRn + HCSBANDHYSTn
Serving cell: SS > HCSBANDTHRs – HCSBANDHYSTs
Else => non-prioritized cells(sorted last in final list according to basic ranking)
If strongest within the own band => HCS ranking listCells not strongest in band => next criteria; must fulfill:
Neighboring cells:SS >= LAYERTHRn + LAYERHYSTn
Serving cell:SS >= LAYERTHRs – LAYERHYSTs
Else => non-prioritized cellsStrongest cells from each layer => HCS ranking list (The rest of cells are non-prioritized & sorted last in final list according to basic ranking)At most only one cell from each layer prioritized for HCS rankingPrioritized cells for HCS ranking are sorted in ascending layer numbering order
HCS - Example
HCS Band
HCS Layer
HCS Layer Discription
HCS BandThr
HCS BandHyst
Layer ThrLayer Hyst
Band 3 Layer2 Inbuilding sites -105 2 -85 2Band 3 Layer3 Micro hotspots -105 2 -70 2Band 3 Layer5 Micro coldspots -105 2 -90 2Band 3 Layer6 Macro cells -105 2 -105 2Band 3 Layer7 Umbrella (High Sites) -105 2 -105 2
-90dBm (serving cell)
-88dBm
Layer 7
Layer 3
Layer 2
Layer 5
-68dBm
-70dBm (serving cell)
-83dBm
-85dBm (serving cell)
-70dBm (serving cell)
-83dBm
-83dBm
-68dBm
Layer 6
-105dBm (serving cell)
-103dBmUmbrella Sites
Macro Cell
900 Micro Cold spot
900 Micro Hot Spot
1800 Micro Hot Spot
Inbuilding 900/1800
85dBm (serving
cell)
HCS - Fast Moving Mobiles
To prevent fast moving mobiles from doing HO to lower layer cells, a penalty is used
PSSTEMP - SS penalty valuePSSTEMP =0, (0 – 63 dB)
PTIMTEMP - SS penalty durationPTIMTEMP = 0, (0 – 600 sec)
FASTMSREG - activates the registration of fast moving MSsFASTMSREG = OFF
THO - time interval to measure the number of HOTHO = 30sec, (range 10 - 100 sec)
NHO - the number of inter-cell HOs ( during THO ) which labels an MS as fast.
NHO = 3, (range 2 -10 HOs)
9702900
HCS – Idle Mode
Normal Cell Selection: the MS will try to select the most suitable cell to camp on.
A cell is considered suitable if:it belongs to the selected PLMN,
it is not barred
it does not belong to a location area included in the list of "forbidden location areas for roaming",
another PLMN than the home PLMN.
the cell selection criterion is fulfilled.
Cell Selection Criterion: While in idle mode, the MS continuously calculates the cell selection quantity, C1.
The cell selection criterion is satisfied if C1 > 0 . C1 = (received signal level - ACCMIN ) - max(CCHPWR - P, 0)
HCS – Idle Mode
Cell Reselection: In order to control the traffic distribution between cells, to favor certain cells in idle mode similarly as in dedicated mode, by HCS.
For example, in a microcell environment there can be a need for controlling the cell reselection rate especially for fast moving mobiles.
For these purposes, additional cell reselection parameters, CRO, TO and PT, are broadcasted on the BCCH of each cell.
The cell reselection process employs a cell reselection quantity C2
HCS – Idle Mode Cell Reselection Algorithm and Parameters
C2 is calculated as follows: C2 = C1 + CRO – TO * H (PT – T) for: PT<>31
C2 = C1 – CRO for: PT=31
T is a timer and CRO, TO and PT are parameters.
CRO: Cell reselection offset. Defines an offset to encourage or discourage MSs to select the cell while it is camping on another cell (0 – 63, 2dB steps)
TO: Temporary offset during PT (0 – 7, 10dB steps)
PT: Defines penalty time (duration) for which TO is applied. (0 – 31, 10 or 20sec intervals, )
HCS parameters
Macro/Micro Settings, example
Parameter Default Recommended Value Unitvalue value range
LAYER 6/2 1 to 8
LAYERTHR 105/70 150 to 0 -dBm
HCSBAND 3 1 to 8
HBANDTHR 105 150 to 0 -dBm
LAYERHYST 2 2 0 to 63 dB
HCSBANDHYST 2 2 0 to 63 dB
PSSTEMP 0 0 0 to 63 dB
PTIMTEMP 0 0 0 to 600 s
FASTMSREG OFF ON, OFF
THO 30 10 to 100 s
NHO 3 2 to 10
HCS Flowchart
A, B, C, D, E, F, G
>Band threshold?
>Layer threshold?
Strongest in band?
Strongest in layer?
HCS Ranking (Layer Ranking)
A,B,C
Basic Ranking
D,E,F,G
Basic Ranking list
No (E)No (B,D,E,F)
No (D, F)
No (G)
Yes (B)
Yes (B, D, F)
Yes (A, C)
Yes (A, B, C, D, E, F)
HCS flowchart
Hierarchical Cell Structure Trial/Example
Investigate Cell Dragging Affects Under HCS Test the functionality of the feature
Slow HO out of Micro HCS Cells
Trial Settings: BTS Power Control Active:
Layerthr=70 (Layer 3 & 5), LayerHyst=2
BTS Power Control Inactive:Layerthr=70 (Layer 3 & 5), LayerHyst=2
BTS Power Control
- 72 dBm
BTS Pwr Ctrl ON: RxLev=-72 – PC Reg – AveDelay = -72 – 10 – 3 = -85 (dBm)BTS Pwr Ctrl OFF: RxLev=-72– AveDelay = -72– 3 = -75 (dBm)
MYA1 - BTS Pwr Ctrl Active
HO Out
HO Out
HO Out
HO Out
MYA1 - BTS Pwr Ctrl Inactive
HO Out
HO Out
HO Out
HO Out
MYA1 - BTS Pwr Ctrl Active (RxQual)
MYA1 - BTS Pwr Ctrl Active (RxQual/RxLev)
MYA1 - BTS Pwr Ctrl Inactive (RxQual)
MYA1 - BTS Pwr Ctrl Inactive (RxQual/RxLev)
3. Multi Band UL/OL (Single BCCH)
General Description
In a multi band cell it is possible to configure two (or three) different frequency bands in a cell with only one BCCH
The BCCH is configured to one of the frequency bands
While TCH resources could be in the other frequency band, provide more capacity to be used for traffic.
To correctly locate MSs, the network has to be aware of the differences in propagation between the bands
Differences in propagation
For the CS traffic, the BSC compensates for the difference, by applying a frequency band group offset, defined by a cell parameter FBOFFS
RxLev = RxLev + FBOFFS.FBOFFS = Propagation (Delta) + EiRPBCCH - EiRPnon-BCCH
Propagation Delta (free space) between GSM900 & 1800 is ~7dBDepending on the environment Propagation difference could be much larger ~10dB is a typical conservative value used
ParametersThe Main controlling parameters should be planned and optimized so they define as accurately as possible the coverage border of the OL
SCTYPE: Identifies the subcell type UL/OLLOL: Pathloss threshold.LOLHYST: Hysteresis for pathloss.TAOL: Timing advance threshold.TAOLHYST: Hysteresis for timing advance. FBOFFS: frequency band group offsetMBCRAC: Defines the way that GPRS/EGPRS MS frequency band capabilities are handled:
0 MS frequency capability is considered when allocating channels for TBF transfers. If not available, only the BCCH frequency band is available. 1 All GPRS/EGPRS MSs are assumed to be capable of both frequency bands.
Other ParametersBSPWR: The BTS output power at the reference point for the BCCH frequencyBSTXPWR: The BTS output power at the reference point for the Non-BCCH frequencies with in a cell. Set per Subcell
Algorithm
Subcell Changes:
UL to OLSS>BSPWR(UL)-LOL+LOLHYST
OL to ULSS_non-BCCH <BSTXPWR(OL) -LOL-LOLHYST-FBOFFS),
BSTXPWRBCCH 40 SS > BSTXPWRBCCH - LOL + LOLHYSTBSTXPWRNON-BCCH 40 SS > -74
LOL 117LOLHYST 3FBOFFS 9
BSTXPWRNON-BCCH - LOL - LOLHYSTSS < BSTXPWRNON-BCCH - LOL - LOLHYST - FBOFFS
SS < -89
Input Parameter Value UnderLay to Overlay (900 to 1800)
SS + FBOFFS <Overlay to UnderLay (1800 to 900)
4. Half Rate
Dynamic Half Rate
Dynamic Half Rate Allocation may allocate Dual Rate capable MS in high load situations.
It is important that the allocation of a channel is done efficiently for a new connection so that high utilization of channels is obtained while good speech quality is maintained for the existing connections
Dynamic Mode Adaptation increases the capacity by changing the mode for ongoing connections from Full Rate to Half Rate
Half Rate connections are packed and Full Rate Channels are therefore released.
If the speech quality for a Half Rate MS becomes unacceptably low the system may upgrade the MS to Full Rate if certain conditions are met
What is Half Rate
idle
idleFR FR FR FR HRHR
1 2 3 4 5 6 7 8
FR FR
idleFR
1 2 3 4 5 6 7 8
FR FR HRHR FR HR
HRidle
idleFR FR FR FR idleFR FR FR FR HRHRHRHR
1 2 3 4 5 6 7 8
FR FR
idleFR
1 2 3 4 5 6 7 8
FR FR HRHRHRHR FR HR
HRHRHR
FR Gross TCH rate = (2*57 Bits/1 Normal Burst) * (1 Normal Burst/ Traffic Frame) *(24 Traffic Frames/26 –Frame Multiframe)
/(120 mSec/26-frame MultiFrame) = 22.8 kbps
HR Gross TCH Rate = (2*(57/2)Bits/1 Normal Burst) * (1 Normal Burst/ Traffic Frame) * (24 Traffic Frames/26 –Frame Multiframe) /
(120 mSec/26-frame MultiFrame) = 11.4 kbps
Half Rate Main Controlling Parameters (I)DHA: is used to turn the feature Dynamic Half Rate Allocation ON or OFF. The parameter is set per cell.DTHNAMR: is the threshold parameter for non AMR HR but DR capable MS:s at channel allocation below which a DR capable MS will be allocated on a HR channel. The parameter expresses the ratio between idle and de-blocked TCH:s in percent and is set per cell.
DMQB is used to switch ON or OFF the quality based channel rate switching from HR to FR. The parameter is set per cell. DMQBNAMR: (45) is the threshold triggering a switch from a HR channel to a FR if the filtered value of either rxqual_dl or rxqual_ul expressed in dtqu units for a non AMR DR capable MS is exceeding this threshold. The higher value of the parameter the poorer radio quality is accepted before switching to FR. The parameter is set per cell and is given in dtqu.
DMQG: is used to switch the quality based channel rate switching from FR to HR channels ON or OFF. The parameter is set per cell.DMQGNAMR: (25-38) is the threshold triggering a switch from a FR channel to a HR if the filtered value of either rxqual_dl or rxqual_ul expressed in dtqu units for a non AMR DR capable MS is less than this threshold. The higher value of the parameter the poorer radio quality is accepted before switching to HR. The parameter is set per cell and is given in dtqu.Note: that to avoid a unstable situation this parameter should be strictly less than DMQBNAMR. Otherwise there is a potential risk of a "ping-pong" effect degrading the performance of the channel allocation algorithm.
DMSUPP: is the parameter controlling the activation of DYMA. It is set per cell. DMTHNAMR: (3-80) is the HR packing threshold parameter for non AMR but DR capable MS:s. Above this value FR channels will have precedence over HR channels in the allocation and below this value HR channels will have precedence over FR channels. The parameter expresses the ratio between idle and de-blocked TCH:s in percent and is set per cell.
Parameter for AMR HR capable MSsDTHAMRDMQBAMRDMQGAMR. DMTHAMR
Half Rate Main Controlling Parameters (II)
Parameter name Default value
Recommended value
Value range Unit
DHA OFF ON ON/OFF -
DMQB OFF ON ON/OFF -
DMQBAMR 50 50 0 to 100 dtqu
DMQBNAMR 45 45 0 to 100 dtqu
DMQG OFF ON ON/OFF -
DMQGAMR 35 35 0 to 100 dtqu
DMQGNAMR 30 30 0 to 100 dtqu
DMSUPP OFF ON ON/OFF -
DMTHAMR 20 20 0 to 100 %
DMTHNAMR 10 10 0 to 100 %
DTHAMR 30 30 0 to 100 %
DTHNAMR 15 15 0 to 100 %
Half Rate Parameters & Algorithm
Dynamic Half Rate Allocation main ParametersDHA
Dynamic Half Rate Allocation, = ON
DTHAMRDynamic HR Allocation threshold AMR capable mobiles [%]
DTHNAMRDynamic HR Allocation threshold for non-AMR-mobiles [%]
Half Rate Algorithm (I)
Must calculate DTHNAMR and DTHAMR based on the configuration of the cell ( 2TRX, 3 TRX, 4TRX, etc) Based on a “commercial” strategy as to when launch AMR HR and plain HR based on how many Timeslots are Idle before DHA actually “kicks-in”?? – How aggressive?DTHNAMR (Non-AMR Connections)= ( # Idle TS’s left in Cell when to Activate HR+1)/( Total # TS’s in the Cell)DTHAMR (ForAMR Connections)= ( # Idle TS’s left in Cell when to Activate HR+1+1)/( Total # TS’s in the Cell)Total TCH’s for Voice = (Total TS’s in Cell – ( BCCH TS - # SDCCH’s TS’s - # FPDCH’s(GPRS/EDGE)
# Idle TS’s for HR or for AMR HR depends on TCH CONG% stats cell by cell, the TCH Utilization % in the Cell, and the actual # TCH’s for Voice Traffic ( i.e. subtract the BCCH, the SDCCH/8’s and the dedicated FPDCH’s for GPRS/EDGE).In other Ericsson networks, this was based (conservatively) on a function (FUNCTION IDLE TS’s) which is a “look-up” table based on the # TCH’s for Voice Traffic and the TCH Utilization % for the cell at BH.
Half Rate Algorithm (II)Lets calculate now the parameters DTHNAMR and DTHAMR
DTHNAMR ( 1 TRX, 1 SDCCH/8 ) = 2/( 8 -1 -1 -1) = 2/5 = 0.4 = 40% , i.e. ( BCCH, 1 SDCCH/8, 1 FPDCH)DTHNAMR ( 2 TRX, 1 SDCCH/8 ) = 2/ ( 16 -1-1-1) = 2/13 = 0.1538 = 15.4%, i.e. ( BCCH, 1 SDCCH/8, 1 FPDCH)DTHNAMR ( 2 TRX, 2 SDCCH/8’s ) = 2/ ( 16 -1-2-1) = 2/12 = 0.1666 = 16.7%, i.e. ( BCCH, 2 SDCCH/8’s, 1 FPDCH)DTHNAMR ( 3 TRX, 2 SDCCH/8’s ) = 2/ ( 24 -1-2-1) = 2/20 = 0.10 = 10.0%, i.e. ( BCCH, 2 SDCCH/8’s, 1 FPDCH)DTHNAMR ( 4 TRX, 2 SDCCH/8’s ) = 2/ ( 32 -1-2-1) = 2/28 = 0.0714= 7.14%, i.e. ( BCCH, 2 SDCCH/8’s, 1 FPDCH)
Now what should be the strategy for AMR HR, should it have the same value as HR?, or if the % penetration of AMR HR MS’s in Maxis is high, should it be set at 1 TS higher than HR?Example:DTHNAMR ( 1 TRX, 1 SDCCH/8 ) = (2+1) /( 8 -1 -1 -1) = 3/5 = 0.6 = 60% , i.e. ( BCCH, 1 SDCCH/8, 1 FPDCH)So with this setting when there are 3 Idle TS’s in the 1 TRX cell, then AMR HR will be set first, although if you notice in the algorithm AMR HR takes priority over plain “HR” if the MS is AMR HR capable! – So AMR HR comes in the moment the # Idle TS’s is less < 60% compared to HR which will only be activated when the condition to be below the threshold of < 40% idle TS’s is met.
NOTE: These parameters ARE NOT STATIC, every week every cell must be checked with TCH UTILIZATION % or OCCUPANCY to see how many Idle TS’s should be considered based on Occupancy!.
Half Rate Algorithm –Function Idle Time Slots
Notice that for :For 1and 2 TRX ( # TCH’s) </= 16 . Idle TS’s = 2 regardless of Occupancy or TCH Utilization.For 3 TRX’s ( # TCH’s) </= 24. Idle TS’s =2 except when the cell has very high TCH Utilization , ie. OCCUPANCY >/= 90%.These settings are “conservative”. They can be changed for the needs of the Operator. Instead of “2” in the Look Up table, may want to try 3 or 4 which will activate DHA sooner.
Technical Description - Performance
Experiment 1b - Test Results
1.0
2.0
3.0
4.0
5.0
Conditions
MOS
Sel. Requir.
AMR-HR
EFR
FR
HR
No Errors
C/I=19 dB
C/I=16 dB
C/I=13 dB
C/I=10 dB
C/I= 7 dB
C/I= 4 dB
5. TCC
Transmitter Coherent Combining, TCC
Ericsson solution to improve Down Link
Enhance power output at ARP from 45.5 dBm to 48 dBm (63 W) from RBS 2206
Two combined transmitters working as one gives 6dB more output than two combined transmitters working as individuals
Antenna combining basic principle
Combine two TX signals onto one antenna (hybrid combining
Half of the power sum from TX1 and 2 will reach the antenna
The other half is dissipated as heath
PAA
PAB
C=0,5A+0,5B
D=0,5A+0,5B
Antenna combining special case
When the TX1 and TX2 signals are identical, then
This function is named TCC
PAA
PAA
C=A+A=2A
D=0
The power sum from TX1 and TX2 will reach the antenna
Nothing will be lost here.
TCC benefits
High output power with Maintained qualitycompensation for aging still remains
compensation for high temperature still remains
IM not applicable since same carrier used
noise is not correlated so no “TCC effect occurs” for noise
MTBF is unaffected (a booster adds problem to the system)
Flexibility since TCC is activated with SW commanddTRU can be reconfigured as normal combined or un-combined
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