how many timeslots available in one E1 ?
32 TS
how many can be used to carry traffic ?
let’s say 26 TS available for traffic
and let’s say you are talking about the A interface, where there is only 1 channel per TS (1 channel = 64kb/s)
now we can say we have 30 TS will be used for BTS ,
every Trx take 2 TS from PCM + 0.5 TS for signaling to this TRX
the summation 2.5 TS related to 1Trx in BTS
now must do calculation how many TRX can carry for 1STM
30/2.5= 12 Trx..
for FR
12*8=96 TS
assume every 4 TRx per sector that mean 2 TS will be decrease for every sector (1BCCH+1SDCCH).
4*8-2=30 TS from Btable 20Erli ber sector