Digital Cellular Telecommunications System (Phase 2+); Base Station Controller - Base Transceiver Station (BSC - BTS) Interface; General Aspects (GSM 08.51 Version 8.0.0 Release 1999)
The present document is an introduction to the 08.5X - 08.6X series of GSM Technical Specifications and deals with the definition of the base station controller (BSC) to base transceiver station (BTS) interface defined inside the base station system (BSS) for the GSM system. These Technical Specifications define the basic interface with some identified options requiring further elaboration. The BSC-BTS interface is mandatory within GSM only if the BSC and the BTS are not colocated.