scope:

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

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

SS-BOC is invoked for outgoing 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.

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 implementation 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 [3].