TG stands for Transceiver Group. It is a group of mutually synchronized Transceivers. One TG is connected to one E1 on Abis. One site has one or more TG’s.
DIP is the digital path on ABIS/A. RBLT stands for “RTS A-Bis interface Line Terminal”. It is the ABIS interface on BSC. Every TG corresponds to one RBLT.