User Manual

Dimensioning rules
Nortel Networks Confidential
5–8
PE/DCL/DD/0063
411–9001–063
Standard 12.07/EN September 2000
GSM/BSS V12
5.2.2 Dimensioning of radio and Abis interfaces
Table 5–1 determines the number of traffic channels (TCH) required per cell, with
an assumption of 25 mE/subscriber at peak time. The jam rate is 2% for the TCHs
and 10–3 for SDCCH.
Config. Standard cell Extended cell
LAPD
channels
Voice
time slot
PCM No.
Erlangs
TCH
Erlangs
TCH
O1 2.27 6 0.6 3 1 2 1
O2 8.20 14 2.23 6 1 4 1
O4 21.0 29 8.20 14 1 8 1
O8 48.7 59 21 29 1 16 1
S11 4.54 12 1.2 6 1 4 1
S44 42 58 16.4 28 1 16 1
S111 6.81 18 1.8 9 1 6 1
S222 24.6 42 6.69 18 1 12 1
S233 36.2 56 17.6 26 1 16 1
S224 37.4 57 12.7 26 1 16 1
S333 42 63 23.1 30 3 18 1
S444 63 87 24.6 42 3 24 1 (E1) or 2 (T1)
S555 81.9 108 34.5 54 3 30 2
S666 104 132 42 63 3 36 2
S777 126 153 52.5 75 3 42 2
S888 146 177 63 87 3 48 2 (E1) or 3 (T1)
111_111 13.62 36 – – 1 12 1
222_222 49.2 84 – – 2 24 1 (E1) or 2 (T1)
444_222 87.6 129 – – 3 36 2
444–444 126 174 – – 3 48 2 (E1) or 3 (T1)
555_333 123.9 171 – – 3 48 2
666_222 128.7 174 – – 3 48 2
Blockage rate: 2%, with full–speed TCU
With measurement pre–processing: 8 DRXs (or e–DRXs) / LAPD
Table 5–1 Dimensioning of radio and Abis interfaces