This Technical Basis for Regulation (TBR) specifies the technical requirements to be met by terminal equipment capable of connecting to a public telecommunications network. These requirements apply to terminals for Phase 2 of the public land mobile radio service, operating in the 900 MHz band with a channel separation of 200 kHz, utilising constant envelope modulation and carrying traffic channels according to the Time Division Multiple Access (TDMA) principle. This TBR specifies the requirements for GSM Telephony (speech) for the GSM900 version of the Global System for Mobile communications (GSM). For each test purpose and its corresponding conformance requirement, a reference is given to ETS 300 607-1 (GSM 11.10-1) [2]. The requirements apply to speech transmission. The measurement uncertainty is handled, as described in ETS 300 607-1 (GSM 11.10-1) [2]. This TBR covers the essential requirements of the Terminal Directive 91/263/EEC [1] Article 4g. Articles 4d, 4e, and 4f are covered by TBR 19. The Terminal Directive 91/263/EEC Articles 4a and 4b are covered by other directives, and, therefore, not by this TBR. In this TBR, there are no Electromagnetic Compatibility technical requirements in terms of the Terminal Directive 91/263/EEC, Article 4c. NOTE: Technical Requirements for EMC performance and testing of the equipment are covered by the relevant standards applicable to the EMC Directive 89/336/EEC, Annex A. Terminal equipment may be subject to additional requirements in other Common Technical Regulations (CTR) depending on the equipments functionality. ETS 300 607-1 (GSM 11.10-1) [2] constitutes the conformance test suite for GSM. The verification of the conformance requirements in this TBR is based on the tests described in this ref rence. The set of requirements in ETS 300 607-1 (GSM 11.10-1) [2] and the set of requirements in this TBR need not be identical. Some requirements only apply to specific types of mobile station (e.g. data tests only apply to mobile stations with a data facility). The TBR also indicates the specific test which shall be carried out for each mobile station type. An active accessory is covered by this TBR if it modifies the terminal performance in an aspect which affects conformance to essential requirements. NOTE: Only active devices are subject to this TBR. Accessories may be tested with specific terminals, and either approved for use with those terminals only, or may possibly be approved for use with a wider range of terminals, depending on the nature and effect of the accessory.