Motorola MTM800 - 7 SDS - Short Data Services; 7.1 Short Data Bearer Service; 7.1.1 Transport Layer Services

SDS - Short Data Services 2-21
September 2008
Chapter 2 - MTM800 Product Information Manual 6866537D87-F
• Specific gateway and repeater: In this mode, the terminal will use only the gateway with the
specified gateway address for that talkgroup and/or a DMO repeater.
• Automatic gateway and repeater: In this mode, the terminal will use the first available
gateway for that talkgroup or a DMO repeater.
If either “specific gateway” or “automatic gateway” mode is chosen, and a suitable gateway is found,
all outgoing calls will be made via the gateway. If a suitable gateway is not found, or a call setup via
the gateway fails, the terminal will attempt to set up the call directly DM-MS to DM-MS.
If the terminal is idle (not involved in a call), it will follow incoming calls from either MS-MS or from a
suitable gateway no matter which gateway mode is chosen.
When the user is operating on a gateway or repeater, the terminal indicates this to the user.
Here is a typical situation where a DMO Gateway enlarges the system coverage:
Benefits:
❏ Increases coverage of a communication system, allowing terminals to operate outside the
normal TETRA system coverage.
❏ In building communication with the Talkgroup when the building is not in the coverage area of
the TETRA system.
7 SDS - Short Data Services
Terminals support Short Data Service (SDS) status and SDS User Defined Data Types 1, 2, 3 and 4
as well as the old SDS-TL standard.
The terminal in DMO supports Short Data Service (SDS) status and SDS User Defined Data Type 4,
both with and without SDS-TL.
7.1 Short Data Bearer Service
The terminal provides a short data bearer service for both internal and external applications.
7.1.1 Transport Layer Services
Terminal supports SDS Transport Layer services that provide end to end acknowledgments, delivery
report requests, message numbering etc. for SDS User Defined Data Type 4 messages. The
Transport Layer (TL) also provides SDS access for applications that do not request these services,
but use a Protocol Identifier.