2G GSM Architecture BTS BSC MSC TRAU GMSC FUNCTION

GSM NETWORK ARCHITECTURE MS Mobile Station Base Transceiver Station BTS Base Station Controller BSC Transcoding Adaptation Unit TRAU Main Switching Center MSC Gateway Main Switching Center GMSC VLR Visitor Location register HLR Home Location register AUC Authentication unit Center EIR Equipment Identity Register OMC /R for Radio OMC /S For Switching