The use and general aspects of the A-bis interface are given in GSM 08 .51. This Global System for Mobile communications Technical Specification ( GTS) gives the principle basis for the rest of the specifications spec ifying the interface between the Base Station Controller (BSC), and th e Base Transceiver Station (BTS), with its transceivers (TRX). These c omponents together form the Base Station System (BSS). (The interface between MSC and the BSS is specified in GSM 08.01 to 08.20.) The intention with this interface is to get a unified way of connectin g remotely located BTSs/TRXs to a BSC allowing for the interconnection of BSCs and BTSs/TRXs from different manufacturers. In order to keep the BTS as simple as possible, BTS contains only thos e functions which have to reside close to the radio interface.