scope:

The present document defines the stage 3 specification of the Barring of Incoming Call (BIC) supplementary service for the Terrestrial Trunked Radio (TETRA).

SS-BIC supplementary service enables barring restrictions for incoming services, e.g. calls, to be set. SS-BIC specifies the definition, interrogation and operation of the supplementary service. The Switching and Management Infrastructure (SwMI) applies the SS-BIC definitions when an incoming service is requested for the restricted user. The SS-BIC actions are defined for the SwMI, for the Mobile Station (MS) and for the Line Station (LS). The SS-BIC information flows may be delivered over the Inter System Interface (ISI).

SS-BIC is invoked for incoming services within one TETRA system or for services that extend over ISI to several TETRA systems.

Man-Machine Interface (MMI) and charging principles are outside the scope of the present document.

Signalling in packet data service is outside the scope of the present document.

According to ITU-T Recommendation I.130 [7], supplementary service stage 3 specification is preceded by the stage 1 and the stage 2 specifications of the service. Stage 1 describes the functional capabilities from the user's point of view. Stage 2 defines the functional behaviour in terms of functional entities and information flows. Stage 3 gives a precise description of the Supplementary Service from the protocol point of view. It defines the protocol for the service and the encoding rules for the information flows. It defines the processes for the functional entities and their behaviour. The described protocols and behaviour apply to the SwMI, for the MS and for the LS and may be applied over the ISI between TETRA systems. Aspects relating to all supplementary services are detailed in EN 300 392-9 [5].