Terrestrial Trunked Radio (Tetra)

This chapter presents Terrestrial Trunked Radio (TETRA), another narrowband Land Mobile Radio (LMR) technology that provides voice and low‐speed data communication capabilities for critical communication systems. It discusses TETRA's technical specifications, network architecture, interfaces and protocols, and services. The standardization process and its future are also discussed. The TETRA architecture features a number of standardized interfaces and allows vendor proprietary interfaces. TETRA specifies two types of air interfaces corresponding to the two fundamental operations involving the base stations and mobile stations. The terminal equipment interface (TEI) is used to exchange data between a mobile station and terminal equipment. Two different types of data services are offered by TETRA: Short Data Services (SDS) and Packet Data Services (PDS). The chapter briefly discusses TETRA standards that specify a relatively comprehensive set of features related to the user and network security. Compared to Project 25 based devices and equipment, TETRA‐based devices and equipment seem to be more cost‐effective.