1. TETRA Gateways and Repeaters
Kenneth Hubner
Regional Director Sepura

2. Introduction What is Direct Mode? Types of Direct Mode Equipment
Benefits of Direct Mode
Gateway and Repeater Applications

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
1. DM-MS Direct Mode capable TETRA terminal
Back-to-back (standard DMO operation)

5. Types of Direct Mode Equipment
1. DM-MS Direct Mode capable TETRA terminal
2. DM-REP Direct Mode Repeater
Repeater
DMO
DMO
DMO
DMO
Extends coverage between DMO terminals

6. Types of Direct Mode Equipment
1. DM-MS Direct Mode capable TETRA terminal
2. DM-REP Direct Mode Repeater
3. DM-GATE Direct Mode Gateway
TETRA
Network
TMO
DMO
TMO
DMO
Control Centre
Relays communication between DMO and TMO

7. Benefits of DMO Allows communication when network is not available
during network rollout
outside network coverage
during network capacity limitations
when a network fails
Allows communication on the boundary of network coverage
Predictable operation in poor signal strenght areas
Extending the network reach with the help of DMO Gateways
Allows communication when no monitoring is wanted
During covert use no monitoring from network might be wanted

8. Gateway and Repeater applications
Unpredictable coverage
In building coverage
Fallback operation
Location of remote users
Extending DMO coverage

9. Gateway and Repeater applications
1. Unpredictable coverage
When leaving 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
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. Gateway and Repeater applications
1. Unpredictable coverage
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. Gateway and Repeater applications
2. 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

12. Gateway and Repeater applications
3. Fallback Operation
Mobile Coverage
Handportable Coverage
Gateway

13. Gateway and Repeater applications
3. Fallback Operation
Mobile Coverage
Handportable Coverage
DMO User
Gateway

14. Gateway and Repeater applications
4. Location of remote users
Users out of coverage can report their position via built-in GPS receiver.
The position report can be sent in DMO to the gateway which can relay it
to TMO users or an operator.
TMO SDS
TETRA
Network
PEI SDS
Gateway
Position Report
TMO SDS
Position Report
DMO SDS
Position Report
Position Report
Mobile Data Terminal

15. Gateway and Repeater applications
5. Extending coverage
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

16. Gateway and Repeater applications
Summary
Direct Mode is 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

17. Any Questions?