EGDE - Enhanced Data rates for GSM Evolution

(E)GPRS Network Infrastructure

How to calculate what

• No. of EGPRS resources used in 1 sector * No. of sectors : 2 x 3

• No. of time slot/sector * no of time slot used for EDAP :- 2 * 3 = 6

• So total time slots per site 6 + 6 = 12

• 1 NSEI support 256 time slot with upgrade % as 10 so total no of time slots which can be equipped is 256 - 10% of 256 = 230.4 ~ 230

• So no. of sites per NSEI is 230/12 = 19.16 ~ 19

• So no NSEI required / BSC : 100 / 19 = 5.2 +1 (for future use) ~ 6

• 2 NSEI supports 1 BCSU so no. of PCU required : 6/2 = 3

• No. of NSEI required is equivalent to the no. of Gb link = 3

• On 1 E1 we can get 31x64 = 1984 , so access rate can be given by 1 E1 = 1984/ access rate (256) = 1984 / 256 ~ 7

Transmission requirement for EGPRS coding schemes in Abis interface

EDGE modulations

EDAP utilization

• 6 EGPRS RTSLs (Dedicated + Default territory)

• 50 % utilization assumed (3 Data Erlangs traffic)

• On average 3 RTSLs used

• RTSLs use MCS7 (44.8 kbit/s) with average C/I=13dB and throughput 30kbit/s

• Effective data rate factor excluding retransmissions over the air-interface is 30/44.8 ~ 0.7

• Slave group utilization is 0.7*0.5= 0.35

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