Terrestrial Trunked Radio (TETRA), a European standard for a trunked radio system, is a professional mobile radio and two-way transceiver specification.

The main advantages of TETRA over other technologies (such as GSM) are: 

  • The much lower frequency used gives longer range, which in turn permits very high levels of geographic coverage with a smaller number of transmitters, thus cutting infrastructure costs.
  • During a voice call, the communications are not interrupted when moving to another network site. This is a unique feature, which dPMR networks typically provide, that allows a number of fall-back modes such as the ability for a base station to process local calls. So called 'mission critical' networks can be built with TETRA where all aspects are fail-safe/multiple-redundant.