The multi-part deliverable EN 300 396 defines the TErrestrial Trunked RAdio (TETRA) Direct Mode Operation
(DMO). It specifies the basic air interface, 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.
The present document applies to the TETRA DMO Gateway (DM-GATE) air interface and contains the specifications
of the physical, Data Link Layer (DLL) and the network layer according to the ISO model.
The specifications contained herein apply to a gateway, both as a standalone unit (DM-GATE) and also to a Direct
Mode Repeater/Gateway (DM-REP/GATE) combined implementation. In the case of a combined implementation the
repeater part of the gateway may be either a type 1A repeater, operating on a single RF carrier, or a type 1B repeater,
operating on a pair of duplex-spaced RF carriers. They also cover the operation of a Direct Mode Mobile Station
(DM-MS) with the gateway.
NOTE: The specifications for a Direct Mode type 1 repeater (either type 1A DM-REP or type 1B DM-REP) are
provided in EN 300 396-4 [4].
The protocol for a DM-MS operating through a gateway is specified in clauses 5 through 8, 14 and 15. Much of this
protocol is defined in the form of a "delta document" relative to the specification provided in EN 300 396-2 [2] and
EN 300 396-3 [3] for direct MS-MS operation. These clauses define where the protocol in EN 300 396-2 [2] and
EN 300 396-3 [3] applies without change, or where it applies with the specified amendments, replacements or additions.
Where no reference to EN 300 396-2 [2] or EN 300 396-3 [3] exists, the clause should be regarded as independent.
The protocol for the gateway is specified in clauses 9 to 13, 16 and 17.
The normative annex mainly specifies the parameter values used in the protocol.