BTS contain three main level (as cards).
1) Antenna coupling level, diff name for it from diff vendor(ANT or CDU……) but mainly it contain (tx combiner+duplexer tx/rx+ rx spliter+ rx,tx filter+ LNA+VSWR detection)
2) TRX level (coder & decoder+channel coding & decoding + VSWR supervission + modulation schame (GMSK or 8PSK)and each trx contain 8Ts)each module is integrated with differ feature(HR,FR,EFR,FH,diversity & some ciphering algorithm)& also handling radio signaling link protocol.
3) Base station function level (it mainly performed by central prosesing unit(SUMA or DXU ….as the vendor define)SO it Generating the clock (internal or syncoronise with external clock), Hndling A-bis TX, Ensuring O&M, Handling OML,Qmux(transimission protocol..& some else control function as the vendor.
# the configuration of TRX may extended up to 12/12/12 for each sectors.