TETRA is mainly used by professional users (law enforcement and commercial or public services) is a topology similar to the GSM. Are two ways terminals can be used: TMO and DMO. Trunking Mode Operation (TMO) is deploying an entire network mesh cellular topology, each MS (Mobile Station) is managed by the MSC (Mobile Subscriber Center) component. However, deploying such as topology is very costly and complex, require advanced technical bits of knowledge. Direct Mode Operation (DMO) allows two MS to interact in the absence of a network. 

As TMO is dedicated and suitable for professional services, DMO can be easily implemented for amateur use. Repeater mode allows setting up a TETRA terminal to act as a repeater, works on the same frequency (both uplink and downlink) receive on slot 1 and transmit on slot 3.

Countries in Europe where TETRA mode is used:

  • Austria
  • Belgium (1)
  • Denmark
  • France (F1ZPQ)
  • The Netherlands
  • Romania (2)


  1. A repeater is expected to be installed by end of 2019 in Bruxelles
  2. DMO used in YO8