to jood: Why you wrote “thus 1 TRX = 2.5 E1 ts” ? if you have 1 TRX per cell then you have to set BCCH at TS=0 on Air int, so first 2 bits in firtst TS on E1 is free of traffic channels, so you may put LAPD link in those 2 bits,
so 1 TRX = 2 TS
Alex
http://www.dx200.biz