This European Telecommunications Standard (ETS) defines the requirements for the transceiver of the pan-european digital mobile cellular and personal communication systems operating in the 900 MHz and 1800 MHz band (GSM 900 and DCS 1800). Requirements are defined for two categories of parameters: - those that are required to provide compatibility between the radio channels, connected either to separate or common antennas, that are used in the system. This category also includes parameters providing compatibility with existing systems in the same or adjacent frequency bands. - those that define the transmission quality of the system. This ETS defines RF characteristics for the Mobile Station (MS) and Base Station System (BSS). The BSS will contain either Base Transceiver Stations (BTS) or microcell base transceiver stations (micro-BTS). The precise measurement methods are specified in GSM 11.10 and 11.20. Unless otherwise stated, the requirements defined in this ETS apply to the full range of environmental conditions specified for the equipment (see Annex D). In this ETS some relaxations are introduced for GSM 900 mobile stations which fulfil the following conditions: - pertain to power class 4 or 5 (see section 4.1.1); - have a total weight less than 200 g (excluding battery); - have a volume less than 500 cm3 (excluding battery). In this standard these mobile stations are referred to as small MS. Mobile stations may operate on more than one of the frequency bands specified in section 2. These mobile stations, defined in GSM 02.06, are refered to as Multi band mobile stations in this standard. Multi band mobile stations shall meet all requiremwnts for each of the bands supported. The relaxation on GSM 900 for a small MS are also va0id for a multi band MS if it complies with the definition of a small MS. The RF characteristics of repeaters are defined in Annex E of this ETS. Annex D and E are the only sections of this ETS applicable to repeaters. Annex E does not apply to the MS or BSS.