This TS specifies the Radio Frequency (RF) test methods and conformanc e requirements for GSM 900 and DCS 1800 Base Station Systems (BSS)s. T hese have been derived from, and are consistent with, the core GSM spe cifications specified in the requirements reference subclause of each test. For each test, two conformance requirements are specified: - essential conformance requirements; - complete conformance requirements. Essential conformance requirements are those which are required: a) to ensure compatibility between the radio channels in the same cell ; b) to ensure compatibility between cells, both co-ordinated and uncoor dinated; c) to ensure compatibility with existing systems in the same or adjace nt frequency bands; d) to verify the important aspects of the transmission quality of the system. Essential conformance requirements are sufficient to verify the perfor mance of the equipment for radio type approval purposes, in countries where this is applicable. Complete conformance requirements may be tested to verify all aspects of the performance of a BSS. These requirements are intended to be use d by manufacturers and operators to allow conformance and acceptance t esting to be performed in a consistent manner; the tests to be perform ed should be agreed between the parties. In some tests there are separate requirements for micro-BTS and BTS. I f there is no separate requirement for a micro-BTS, the requirements f or the BTS apply to a micro-BTS. In this TS, the reference point for RF connections (except for the mea surement of mean transmitted RF carrier power) is the antenna connecto r, as defined by the manufacturer. This TS does not apply to repeaters or RF devices which may be connected to an antenna connector of a BSS .