Terrestrial Trunked Radio (TETRA); Technical Requirements for Direct Mode Operation (DMO); Part 3: Mobile Station to Mobile Station (MS-MS) Air Interface (AI) Protocol
This European Telecommunications Standard (ETS) defines the TErrestrial Trunked RAdio (TETRA) Direct Mode Operation (DMO). It specifies the basic Air Interface (AI)@ the inter-working between Direct Mode (DM) groups via repeaters@ and inter-working with the TETRA Voice plus Data (V+D) system via gateways. It also specifies the security aspects in TETRA DMO@ and the intrinsic services that are supported in addition to the basic bearer and teleservices. This part applies to the TETRA DMO Mobile Station - Mobile Station (MS-MS) AI and contains the specifications of the Data Link Layer (DLL) and the network layer according to the ISO model. It establishes the services@ messages and protocols used for voice and circuit mode data calls and short data transfer@ starting with the upper layers; - it defines and specifies the protocol used by the layer 3 entity to communicate across the AI; - it defines and specifies the services and protocol used in the DLL. The normative annexes mainly specify the parameter values used in the protocol.