A European standard for packet-mode mobile data

An activity has been set up to develop a public standard for trunked radio and mobile data systems. The standards being developed are generically known as TETRA, standing for trans-European trunked radio. The ETSI is responsible for defining the TETRA standard. TETRA is really a family of standards. One branch of the family is a set of radio and network interface standards for trunked voice (and non-optimised data) services; the other branch is an air-interface standard optimised for providing classic wide-area packet data services at mobile access points, allowing a packet data network to be built with both fixed and mobile subscribers and supporting standard network access protocols. The paper gives an overview of the TETRA mobile data standard at its current stage of development. It discusses the general service requirements for the network, then concentrates on the design of the lower layers of the air-interface protocol itself