The present document defines the stage 1 specifications of the Supplementary Service Late Entry (SS-LE) for the
Trans-European Trunked Radio (TETRA). Stage 1 is an overall service description from the users point of view but
does not deal with the details of the human interface itself.
The present document specifies the service description of the supplementary service and the procedures to be expected
with successful and unsuccessful outcomes. In addition the present document specifies the interactions with other
TETRA supplementary services and interworking considerations.
Charging principles are outside the scope of the present document.
The SS-LE allows radio users to be informed of and, if they are concerned, to join an already existing multipoint speech
or data call.