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Reputation: 1017
How to Calculate and Expand the Bandwidth for FACH
1. For high FACH Congestion after expand 2 nd SCCPCH we can expand FACH Bandwidth by re-config the SCCPCH Parameter, how the new bandwidth for FACH is calclated and what parameter involved?
2. How to expand FACH bandwidth from 36K to 72K?
I. For high FACH Congestion after expand 2nd SCCPCH we can expand FACH Bandwidth by re-config the SCCPCH Parameter . how the new bandwidth for FACH is calclated and what parameter involved.
---- RLCSize/ TFsNumber/ TbNumber1/ TbNumber2/ TbNumber3 shall involved to calculate the bandiwidth for FACH.
For example, below is the script for expansion FACH bandwidth.
Because TFsNumber = D3, so TbNumber3 refered, it equal to 2.
ADD UFACHDYNTFS: CellId=XXXX, TrChId=5, RLCSize=360, TFsNumber=D3, TbNumber1=0, TbNumber2=1, TbNumber3=2;
In the configuration, RLCSize* TbNumber(TFsNumber) = 360*2=720bit, so 720bit can be send per TTI, => 720bit/8=90byte can be send per TTI.
We know the TTI = 10 ms, so the bandwidth is 90*100(1s=1000ms, 100=1000ms/1 TTI) = 9000byte/s = 9 kbytes/s
If there is no expansion for FACH bandwidth, the bandwidth should be 360*1/8*100=45*100=4.5kbytes/s
II. How to expand FACH bandwidth from 36K to 72K?
1 Description
1)Change the slot format from D8(SF64) to D10(SF32) to support higher bit rate.
2)Add three new TFC(4,5,6)
3)Increase the max FACH power to +3dB to optimize the RRC failures brought by decreased SF gain.
Remember to use the old value when making rollback script.
4) Set TbNumber3=2 for user plane, to support format of 2*360
5) The script for cell without CBS is different with cell with CBS
2 Activation script for cell without CBS DEA UCELL: CellId=51058;
DEA USCCPCH: CellId=51058, PhyChId=9;
RMV UFACHLOCH: CellId=51058, TrChId=4;
RMV UFACHDYNTFS: CellId=51058, TrChId=4, RLCSize=168;
RMV UFACHDYNTFS: CellId=51058, TrChId=5, RLCSize=360;
RMV UFACH: CellId=51058, TrChId=4;
RMV UFACH: CellId=51058, TrChId=5;
RMV USCCPCH: CellId=51058, PhyChId=9;
ADD USCCPCHBASIC: CellId=51058, PhyChId=9, SCCPCHOffset=70, ScrambCode=0, STTDInd=FALSE, PO1=8, CTFCSize=BIT4, PilotSymbolExist=NOT_EXISTS, SlotFormat=D10, TFCIpresence=EXISTS, MultiplexPos=FLEXIBLE, MbmsChInd=COMMON;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=0;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=1;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=2;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=3;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=4;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=5;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=6;
ADD UFACH: CellId=51058, PhyChId=9, TrChId=4, TTI=T10, RateMatchingAttr=220, ToAWS=35, ToAWE=10, MaxFachPower=30, MaxCmchPi=D15, MinCmchPi=D14, SigRbInd=TRUE, ChCodingType=CONVOLUTIONAL, CodingRate=D1/2;
ADD UFACH: CellId=51058, PhyChId=9, TrChId=5, TTI=T10, RateMatchingAttr=130, ToAWS=35, ToAWE=10, MaxFachPower=30, MaxCmchPi=D13, MinCmchPi=D0, SigRbInd=FALSE, ChCodingType=TURBO;
ADD UFACHDYNTFS: CellId=51058, TrChId=4, RLCSize=168, TFsNumber=D3, TbNumber1=0, TbNumber2=1, TbNumber3=2;
ADD UFACHDYNTFS: CellId=51058, TrChId=5, RLCSize=360, TFsNumber=D3, TbNumber1=0, TbNumber2=1, TbNumber3=2;
ADD UFACHLOCH: CellId=51058, TrChId=4, SDUDiscardTimer=T10, MaxPduSize=20;
ACT USCCPCH: CellId=51058, PhyChId=9;
ACT UCELL: CellId=51058;
Nine transmission format (168 is signaling plane, 360 is user plane)
0: 0*168, 0*360
1: 1*168, 0*360
2: 2*168, 0*360
3: 0*168, 1*360
4: 1*168, 1*360
5: 2*168, 1*360
6: 0*168, 2*360
3 Rollback script for cell without CBS DEA UCELL: CellId=51058;
DEA USCCPCH: CellId=51058, PhyChId=9;
RMV UFACHLOCH: CellId=51058, TrChId=4;
RMV UFACHDYNTFS: CellId=51058, TrChId=4, RLCSize=168;
RMV UFACHDYNTFS: CellId=51058, TrChId=5, RLCSize=360;
RMV UFACH: CellId=51058, TrChId=4;
RMV UFACH: CellId=51058, TrChId=5;
RMV USCCPCH: CellId=51058, PhyChId=9;
ADD USCCPCHBASIC: CellId=51058, PhyChId=9, SCCPCHOffset=70, ScrambCode=0, STTDInd=FALSE, PO1=8, CTFCSize=BIT4, PilotSymbolExist=NOT_EXISTS, SlotFormat=D8, TFCIpresence=EXISTS, MultiplexPos=FLEXIBLE, MbmsChInd=COMMON;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=0;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=1;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=2;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=3;
ADD UFACH: CellId=51058, PhyChId=9, TrChId=4, TTI=T10, RateMatchingAttr=220, ToAWS=35, ToAWE=10, MaxFachPower=10, MaxCmchPi=D15, MinCmchPi=D14, SigRbInd=TRUE, ChCodingType=CONVOLUTIONAL, CodingRate=D1/2;
ADD UFACH: CellId=51058, PhyChId=9, TrChId=5, TTI=T10, RateMatchingAttr=130, ToAWS=35, ToAWE=10, MaxFachPower=10, MaxCmchPi=D13, MinCmchPi=D0, SigRbInd=FALSE, ChCodingType=TURBO;
ADD UFACHDYNTFS: CellId=51058, TrChId=4, RLCSize=168, TFsNumber=D3, TbNumber1=0, TbNumber2=1, TbNumber3=2;
ADD UFACHDYNTFS: CellId=51058, TrChId=5, RLCSize=360, TFsNumber=D2, TbNumber1=0, TbNumber2=1;
ADD UFACHLOCH: CellId=51058, TrChId=4, SDUDiscardTimer=T10, MaxPduSize=20;
ACT USCCPCH: CellId=51058, PhyChId=9;
ACT UCELL: CellId=51058;
Four transmission format (168 is signaling plane, 360 is user plane)
0: 0*168, 0*360
1: 1*168, 0*360
2: 2*168, 0*360
3: 0*168, 1*360
4 Activation script for cell with CBS DEA UCELL: CellId=51058;
DEA USCCPCH: CellId=51058, PhyChId=9;
DEA UCELLCBS: CellId=51058;
RMV UCTCH: CellId=51058, FachId=4;
RMV UFACHLOCH: CellId=51058, TrChId=4;
RMV UFACHDYNTFS: CellId=51058, TrChId=4, RLCSize=168;
RMV UFACHDYNTFS: CellId=51058, TrChId=5, RLCSize=360;
RMV UFACH: CellId=51058, TrChId=4;
RMV UFACH: CellId=51058, TrChId=5;
RMV USCCPCH: CellId=51058, PhyChId=9;
ADD USCCPCHBASIC: CellId=51058, PhyChId=9, SCCPCHOffset=70, ScrambCode=0, STTDInd=FALSE, PO1=8, CTFCSize=BIT4, PilotSymbolExist=NOT_EXISTS, SlotFormat=D10, TFCIpresence=EXISTS, MultiplexPos=FLEXIBLE, MbmsChInd=COMMON;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=0;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=1;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=2;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=3;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=4;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=5;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=6;
ADD UFACH: CellId=51058, PhyChId=9, TrChId=4, TTI=T10, RateMatchingAttr=220, ToAWS=35, ToAWE=10, MaxFachPower=30, MaxCmchPi=D15, MinCmchPi=D14, SigRbInd=TRUE, ChCodingType=CONVOLUTIONAL, CodingRate=D1/2;
ADD UFACH: CellId=51058, PhyChId=9, TrChId=5, TTI=T10, RateMatchingAttr=130, ToAWS=35, ToAWE=10, MaxFachPower=30, MaxCmchPi=D13, MinCmchPi=D0, SigRbInd=FALSE, ChCodingType=TURBO;
ADD UFACHDYNTFS: CellId=51058, TrChId=4, RLCSize=168, TFsNumber=D3, TbNumber1=0, TbNumber2=1, TbNumber3=2;
ADD UFACHDYNTFS: CellId=51058, TrChId=5, RLCSize=360, TFsNumber=D3, TbNumber1=0, TbNumber2=1, TbNumber3=2;
ADD UFACHLOCH: CellId=51058, TrChId=4, SDUDiscardTimer=T10, MaxPduSize=20;
ACT USCCPCH: CellId=51058, PhyChId=9;
ACT UCELL: CellId=51058;
ADD UCTCH: CellId=51058, FachId=4;
ACT UCELLCBS: CellId=51058;
Nine transmission format (168 is signaling plane, 360 is user plane)
0: 0*168, 0*360
1: 1*168, 0*360
2: 2*168, 0*360
3: 0*168, 1*360
4: 1*168, 1*360
5: 2*168, 1*360
6: 0*168, 2*360
5 Rollback script for cell with CBS DEA UCELL: CellId=51058;
DEA USCCPCH: CellId=51058, PhyChId=9;
DEA UCELLCBS: CellId=51058;
RMV UCTCH: CellId=51058, FachId=4;
RMV UFACHLOCH: CellId=51058, TrChId=4;
RMV UFACHDYNTFS: CellId=51058, TrChId=4, RLCSize=168;
RMV UFACHDYNTFS: CellId=51058, TrChId=5, RLCSize=360;
RMV UFACH: CellId=51058, TrChId=4;
RMV UFACH: CellId=51058, TrChId=5;
RMV USCCPCH: CellId=51058, PhyChId=9;
ADD USCCPCHBASIC: CellId=51058, PhyChId=9, SCCPCHOffset=70, ScrambCode=0, STTDInd=FALSE, PO1=8, CTFCSize=BIT4, PilotSymbolExist=NOT_EXISTS, SlotFormat=D8, TFCIpresence=EXISTS, MultiplexPos=FLEXIBLE, MbmsChInd=COMMON;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=0;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=1;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=2;
ADD USCCPCHTFC: CellId=51058, PhyChId=9, CTFC=3;
ADD UFACH: CellId=51058, PhyChId=9, TrChId=4, TTI=T10, RateMatchingAttr=220, ToAWS=35, ToAWE=10, MaxFachPower=10, MaxCmchPi=D15, MinCmchPi=D14, SigRbInd=TRUE, ChCodingType=CONVOLUTIONAL, CodingRate=D1/2;
ADD UFACH: CellId=51058, PhyChId=9, TrChId=5, TTI=T10, RateMatchingAttr=130, ToAWS=35, ToAWE=10, MaxFachPower=10, MaxCmchPi=D13, MinCmchPi=D0, SigRbInd=FALSE, ChCodingType=TURBO;
ADD UFACHDYNTFS: CellId=51058, TrChId=4, RLCSize=168, TFsNumber=D3, TbNumber1=0, TbNumber2=1, TbNumber3=2;
ADD UFACHDYNTFS: CellId=51058, TrChId=5, RLCSize=360, TFsNumber=D2, TbNumber1=0, TbNumber2=1;
ADD UFACHLOCH: CellId=51058, TrChId=4, SDUDiscardTimer=T10, MaxPduSize=20;
ACT USCCPCH: CellId=51058, PhyChId=9;
ACT UCELL: CellId=51058;
ADD UCTCH: CellId=51058, FachId=4;
ACT UCELLCBS: CellId=51058;
Four transmission format (168 is signaling plane, 360 is user plane)
0: 0*168, 0*360
1: 1*168, 0*360
2: 2*168, 0*360
3: 0*168, 1*360
Last edited by mounir34; 2017-06-07 at 02:42 AM
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2017-06-07 02:31 AM
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Reputation: 1791
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Re: How to Calculate and Expand the Bandwidth for FACH
found on internet looks good.
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