1. TETRA Gateway and Repeater Applications for Voice and Data
Steve Barber
Market Development Manager
Sepura Limited

2. Introduction What is Direct Mode?
Types of Direct Mode Equipment DM-REP
Types of Direct Mode Equipment DM-GATE
Typical applications of DMO Services?

3. What is Direct Mode ?
Direct Mode is direct communication between two or more TETRA terminals without the use of a network infrastructure.

4. Types of Direct Mode equipment
DM-MS Direct Mode capable TETRA Terminal
Back-to-back (standard DMO operation)

5. Types of Direct Mode equipment
DM-REP Direct Mode Repeater
Repeater
DMO
DMO
DMO
Extends coverage between DMO terminals

6. Types of Direct Mode equipment
DM-GATE Direct Mode Gateway
DMO
TMO
Gateway
TETRA
Network
Gateways and repeaters will interact intelligently with other Gateway and repeater terminals operating within range. When switched into Gateway mode will monitor for other Gateways…………..
If a conflict is found they will stay in a monitoring state when:
DMO channel is occupied or reserved
Presence signal is detected from another Gateway
When the conflict disappears will become active as a Gateway.
Control Centre
Relays communication between DMO and TMO

7. Infrastructure Limitations for Gateways
To support individual call types DM-GATE must register DM-Gate users with the SwMI
No network infrastructure supports this registration operation
Hence SwMI sees DM-GATE as just another terminal on the system
Cannot address individual calls (voice or SDS) to the intended user

8. Benefits of DMO
Operation outside of the coverage of a TETRA Infrastructure
Predictable operation in poor signal strength areas
Covert use, no monitoring from the network can take place
Communications when there are capacity limitations on a network
Communication when a network fails
DMO Gateway extends the operational reach of a network
DMO economic solution to coverage at edge of network or rural areas
Enhanced coverage during network roll-out

9. Applications of Gateways and Repeaters
Unpredictable Coverage
When users leave a vehicle, handportable coverage may not be predictable:
Operating in built up areas
Roaming into public buildings (shopping centres etc.)
Operating near large metallic structures
Operating in a rural environment
Switching into DMO provides some predictable guidelines to
follow for coverage planning
Using a Repeater will allow coverage area to be extended
Using a Gateway will allow handportable operation in DMO,
whilst still enabling communications with trunked mode users.

10. Applications of Gateways and Repeaters
Using DMO in this way can be useful for:
Police officers when operating on foot after leaving a
vehicle
Fire crews using the appliance as a gateway or
repeater on the fire ground
Ambulance Crews leaving the vehicle to attend to
patients
Transportation users when parked in depots use
Gateway for communications to Trunked mode users

11. Applications of Gateways and Repeaters
Workflow Management
Data messaging (SDS) can be received by a gateway and forwarded on to DMO users
Mobile Data terminals can also be kept informed of data transactions
TETRA
Network
TMO SDS
Gateway
PEI SDS
Mobile Data Terminal
DMO SDS

12. Applications of Gateways and Repeaters
Mobile data terminals can be used to “Page” Direct mode users, depending upon the circumstances it detects:
Receipt of message from TMO
Vehicle battery flat warning
Return to Vehicle
TETRA
Network
Gateway
PEI SDS
No Network Coverage
DMO SDS
Mobile Data Terminal

13. Applications of Gateways and Repeaters
Location of Remote Users – Manage Resource in DMO
Users out of coverage of the network can report their current position to either their vehicle or to an operator via TMO and to their vehicle
Alarm indications can report the position of the originator
TETRA
Network
TMO SDS
PEI SDS
Gateway
Position Report
Position Report
DMO SDS
Position Report
Mobile Data Terminal

14. Applications of Gateways and Repeaters
In Building Coverage
Large buildings such as power stations, storage buildings and metallic structured buildings may have no TMO coverage
A Gateway, can be used to allow
DMO communications within the
building, and a link to TMO users
Outside of the building
TMO
TETRA Infrastructure
Gateway
DMO
DMO User
Underground Bunker

15. Applications of Gateways and Repeaters
Fallback operation
DMO User
Gateway
Mobile Coverage
Handportable Coverage

16. Applications of Gateways and Repeaters
Provide coverage between two geographically separated sites when there is no network coverage available
Site B
Site A
DMO
DMO
Repeater
DMO User
DMO User

17. Summary
Direct Mode provides a complementary service to Trunked Mode operation
Utilisation of DMO Gateways and Repeaters provides:
Network extension capabilities
Predictability of coverage for working practices
Workflow Management
Location and management of DMO users from network Control Centres
Fallback scenarios, when base station sites fail
DMO must be classed as an essential service in Public Safety, Transportation and Utility networks

18. Kamsa hamnida Any Questions?