SSH ETS 300 392-11-20:1999 ed.1

Terrestrial Trunked Radio (TETRA); Voice plus Data (V+D); Part 11: Supplementary services stage 2; Sub-part 20: Discreet Listening (DL)

Scope

This European Telecommunication Standard (ETS) specifies the stage 2 description of the Supplementary Service Discreet Listening (SS-DL) for the Terrestrial Trunked Radio (TETRA). The SS-DL supplementary service discreet listening allows a user to monitor calls involving specified TETRA subscribers, either individuals or groups, or specified circuit mode basic services, or a specified combination of both. Man-Machine Interface and charging principles are outside this ETS. As an implementation option, this SS-DL may either result in a forced call clear or an intrusion in an existing call.