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HUAWEI TECHNOLOGIES Co., Ltd.
www.huawei.com
HUAWEI Confidential
GSM Abis Dimensioning
HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 2
Traditional Transmission——Abis of TDM over E1
Abis E1 Dimension Principle for FullRate:
15 FR TRX per E1
S555 configuration: 1 BCCH per cell; 3 SDCCHs per cell; TCH channel = 5*8-1-3=36 Signaling : 1 RSL / TRX, 1 OML / Site, RSL or OML occupy one 16kbps timeslotTotal 16kbps channel required= 36*3+15+1=124= 124/4=31 64kpbs timeslot= 1 E1
HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 3
Abis E1 Dimension Principle for HalfRate:
About 13 100%HR TRX per E1
About (15-2*HR Ratio) TRX per E1
Traditional Transmission——Abis of TDM over E1
HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 4
Transmission Optimization——Abis of IP over E1
Abis Interface ThroughputAbis Interface Throughput
Control Plane Throughput
Control Plane Throughput
User Plane ThroughputUser Plane Throughput
T _Control PlaneT _Control Plane T _User PlaneT _User Plane
Abis throughput factors:Ø Signalling Overhead in control planeØgeneral consider signaling throughput is equal to 10% CS user throughput
Dimensioning Procedure:
HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 5
L1(PHY)
IP
UDP
MAC
RSL/OML
LAPD
Control PlaneControl Plane User PlaneUser Plane Payload (bits)
Payload ( MAC Layer)
264
Internal defined header
32
IP_UDP header 224
PPP header 56
Voice frame len / 20ms (bit)
576
IP
UDP
Transmission Optimization——Abis of IP over E1
Abis Interface Protocol Stack (IP over E1) Protocol Overhead in user plane-CS part
PPP
HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 6
Dimensioning Procedure - User Plane
Voice frame len / 20ms (bit) =Payload ( MAC Layer) + internal defined header + IP_UDP header + PPP header=576 bits
Voice frame len / 20ms (bit) =Payload ( MAC Layer) + internal defined header + IP_UDP header + PPP header=576 bits
INPUT• VAD Factor = 0.5• MAC Packet Size = 264 bits• Packet time = 20ms
• VAD Factor = 0.5• MAC Packet Size = 264 bits• Packet time = 20ms
Voice frame bit rate / UM channel(kbps)W/O Mux=voice frame len / 20ms (bit) * 50 * VAD / 1024=14.1kpbs
Voice frame bit rate / UM channel(kbps)W/O Mux=voice frame len / 20ms (bit) * 50 * VAD / 1024=14.1kpbs
Transmission Optimization——Abis of IP over E1
HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 7
Avg frame bit rate (kbps) with MUX=Mux total size*50*VAD factor/1024/Mux number=8.8kbps
Avg frame bit rate (kbps) with MUX=Mux total size*50*VAD factor/1024/Mux number=8.8kbps
Mux Total Size (bit) with MUX=8*(Payload ( MAC Layer)+56) + internal defined header + IP_UDP header + PPP header=2872
Mux Total Size (bit) with MUX=8*(Payload ( MAC Layer)+56) + internal defined header + IP_UDP header + PPP header=2872
Maximum MUX number = 8Maximum MUX number = 8
End of CS User Plane
Dimensioning Procedure - User Plane
Transmission Optimization——Abis of IP over E1
speech version(Code Scheme)
Payload in RLC/MAC layer (bit)
Avg frame bit rate(kbps)
FR 264 8.8
EFR 248 8.4
AMR-FR12.2 264 8.8
HR 120 5.2
AMR-HR7.95 176 6.6
CS-1 160 6.4
CS-2 240 8.4
CS-3 288 9.5
CS-4 400 12.3
MCS-1 176 6.8
MCS-2 224 8.0
MCS-3 296 9.7
MCS-4 352 11.1
MCS-5 448 13.5
MCS-6 592 17.0
MCS-7 896 24.4
MCS-8 1088 29.1
MCS-9 1184 31.4
HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 8
Example - Abis of IP over E1
CS channel bandwidth (Kbps)=(1-LCLS percentage)*Avg frame bit rate (kbps) with MUX for CS* Total voice number/BH=(1-10%)*8.8*84=665.28 kbpsPS channel bandwidth (Kbps)=Number of Activated PDCHs in Busy Hours*Avg frame bit rate (kbps) with MUX for PS=3*31.4=97.2kbpsSignaling bandwidth (Kbps)=10% *CS channel bandwidth (Kbps)=10%*665.28=66.53kbpsTotal Abis requirement (Kbps)=(CS channel bandwidth (Kbps)+ PS channel bandwidth (Kbps)+ Signaling bandwidth (Kbps))/Transmission Link Bandwidth Utilization=(665.28+97.2+66.53)/85%=975.31kbpsTotal Abis timeslot requirement (64Kbps)=Roundup (Total Abis requirement (Kbps)/ 64kbps,0)+1=Roundup(975.31/64,0)+1=17
Dimensioning Procedure Case study: supposed S444; 10% LCLS; 100% FR; 3 Activated MCS9 PDCHs; 85%Transmission Link Bandwidth Utilization
HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 9
Abis Dimensioning for S111 ConfigurationAssumption1: (1) S111; (2) 10% LCLS; (3) 20% HR; (4) 2 Activated MCS9 PDCHs;(5) 85%Transmission Link Bandwidth Utilization
Transmission Method Abis Bandwidth (Kbps)
Abis IP over FE/GE 379.62
Abis IP over E1/T1 326.32
Assumption2: (1) S111; (2) 10% LCLS; (3) 20% HR; (4) 2 Activated DAS-12 PDCHs (EDGE+);(5) 85%Transmission Link Bandwidth Utilization
Transmission Method Abis Bandwidth (Kbps)
Abis IP over FE/GE 494.47
Abis IP over E1/T1 402.89
Thank youwww.huawei.com