scope:

This European Telecommunication Standard (ETS) defines the Trans-European Trunked Radio (TETRA) system Direct Mode Operation (DMO). It specifies the basic air interface, the inter-working between DM groups via Direct Mode Repeaters (DM-REP), and inter-working with the TETRA voice plus Data (V+D) system via Direct Mode Gateways (DM-GATE). 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 DM-REP air interface and contains the specifications, where applicable, of the physical, data link and network layers according to the ISO model.

The specifications contained herein apply to a DM-REP as a stand-alone unit and also to the DM-REP portion of a Direct Mode Repeater/Gateway (DM-REP/GATE) combined implementation.The specification also covers the operation of a DM-MS with a DM-REP.

The protocol for a DM-MS operating through a DM-REP is specified in clauses 5 through 8, 10 and 11. Much of this protocol is defined in the form of a "delta document" relative to the specification provided in ETS 300 396-2 [3] and ETS 300 396-3 [4] FOR DIRECT MS-MS operation. These clauses define where the protocol in parts 2 and 3 applies without change, or where it applies with the specified amendments, replacements or additions. Where no reference to parts 2 or 3 exists, the sub clause should be regarded as independent.

The protocol for the DM-REP is specified in clauses 9 and 12.

The normative annexes mainly specify the parameter values used in the protocol.