This Harmonized Standard specifies the technical characteristics to be provided by TETRA terminal equipment which is capable of connection to a Public Telecommunications Network (PTN) and which uses the TETRA technology. The objective of this Harmonized Standard is to ensure that no disturbance occurs to the PTN, and to ensure interworking btw. PTN and TETRA terminals and btw. TETRA terminal to TETRA terminal so that the communication can be routed successfully through the applicable network(s). The requirements in this Harmonized Standard apply together with the attachment requirements for the appropriate PTN and the requirement of any other applicable Harmonized Standard . It does not add or reduce the attachment requirements unless there is a particular effect on the network which is unique to TETRA. Note: appropriate PTN refers to Harmonized Standard for basic rate ISDN, Harmonized Standard for primary rate ISDN or national regulations (implemeting ETS 300 001) for PSTN. TETRA terminal equipment consists of several elements. This Harmonized Standard is structured to allow testing and approval of the individual elements as separate items. Because of the need for effective use of the radio frequency spectrum, the essential air interface characteristics shall be tested. For each essential requirement, a test is given including measurement methods. Requirements apply to the public network interface and the RF Air Interface of the equipment, which may be stimulated to perform the tests by additional equipment, if necessary. Terminal equipment may be subject to additional requirements in other applicable CTRs or Directives depending on the functionality (primary functions). This Harmonized Standard is based on the radio and protocol provisions of ETS 300 394. This document is a general Harmonized Standard for TETRA terminal equipment, however, only certain applications are subject to Directive 91/263/EEC and hence covered by a CTR. It is therefore necessary to check with the relevant CTR as to the applicability to specific applications.