TETRA Communications

TETRA (Terrestrial Trunked Radio) is the most robust technology for commercial radio systems having been developed specifically for government agencies and the emergency services i.e. mission critical communications.

How does TETRA work?

In conventional systems a separate channel is allocated to each user group (e.g. cleaning, security etc.) and users have to manually switch frequency to change groups. The disadvantage of this is that while one channel is busy and has radio users waiting another may be unused. TETRA overcomes this issue by automatically allocating channels. This is obviously a major advantage for users with a large number of users.

The success and market uptake of TETRA in a wide range of sectors outside its original target has attracted many manufacturers and suppliers of products and services creating healthy competition and making TETRA more price competitive and economically viable for an increasing range of applications.


TETRA has much to recommend it:

Technology developed for the most challenging mission critical applications

TETRA, which was the first digital radio technology, has been proven in some of the most challenging applications in the world offering scale, security and high-quality communications.


TETRA supports terminal registration, authentication and encryption.


TETRA can communicate in direct-mode operation (DMO) or trunked-mode operation (TMO). In direct mode operation (DMO) radios can maintain communication when the network is not available, i.e. when two radio users are out of range they can still talk to each other. When connected to the network radios in DMO can act as a relay for other radios that are out of range.

Fast data advanced apps

TETRA radios can process data applications while simultaneously receiving or sending voice calls, making better use of the spectrum.

Specially designed apps can

  • Combine a geographical information system, voice recording and radio dispatch
  • Issue visual alerts, swiftly delivering images to TETRA radios and Java-enabled devices
  • Access to multiple databases


TETRA uses a lower frequency than alternatives, which gives longer range, increasing coverage and reducing the number of transmitters required, thus cutting infrastructure costs.

 Full duplex calling

TETRA enables users to talk exactly as they would on a mobile device with both parties able to speak simultaneously.


Single site, multiple site or regional networks are all possible. A TETRA fully trunked multi-site system can accommodate over 100 radio users, equivalent to a DMR Tier III fully trunked multi-site system.

 Open-standard technology

TETRA is an open-standard, multi-vendor technology so you can mix and match products from different suppliers and create a system to suit your needs. The success of TETRA has created a strong base of application developers who are able to provide a wide variety of applications for use with TETRA.

Easy to licence

Currently obtaining a TETRA licence is a straightforward process and pricing is comparable to analogue and digital licences, which are sometimes difficult to obtain, especially in London.

In addition to the above TETRA shares key features of DMR alternatives, including remote network management, roaming between sites, repeater data interface and dispatcher software.

There are also some considerations in choosing TETRA:


TETRA is not compatible with analogue or other DMR systems. Uptake of TETRA requires investment in a completely new system.


The range of TETRA radios operating in peer to peer (DMO) mode is less than that of DMR or analogue.

The best radio systems are those that meet the organisation’s requirements, whilst it is important to anticipate likely future requirements adding unnecessary complexity or over specifying tends to only add to costs.