5 Normal operation with successful outcome

3GPP42.069Release 17Stage 1TSVoice Broadcast Service (VBS)

5.1 Provision

The VBS is provided to be used by a service subscriber after prior arrangements with the service provider. The provision includes the assignment of group IDs to the service subscriber. A subscription shall not provide more than 50 group IDs to the service subscriber.

The service can be offered with two subscription options:

Subscription option	Value
– subscriber has the capability of initiating voice broadcast calls	No
	Yes;
– subscriber has the capability to initiate voice broadcast calls in case of roaming	No
	Yes.

5.2 Withdrawal

The VBS is withdrawn at the service provider’s request or for administrative reasons.

5.3 Network related service configuration

The network related service configuration defines the attributes of a particular voice broadcast call which shall be pre-registered in the network by the service provider. This is not related to one specific service subscriber.

The attributes of a particular broadcast call are group ID, group call area composition, a list of dispatcher identities to be connected to this area, a list of dispatchers allowed to initiate voice broadcast calls to this area, the broadcast call reference identity which shall be used in case of COLP (see subclause 7.3) and recipient identities to which an optional acknowledgement can be routed. Changes to the group call area composition shall be co-ordinated with the network operator.

5.4 Normal operation for voice broadcast call establishment

The VBS service shall be automatically initiated by the network when a calling service subscriber or calling dispatcher dials a particular short code or address at call set-up.

On successful initiation of the VBS, the voice broadcast call shall be established between the calling service subscriber or calling dispatcher and the destination subscribers. The destination subscribers are:

– all destination service subscribers at any time during the voice broadcast call with the corresponding active group ID when located in the group call area, where the group call area is uniquely defined by:

– the location (radio cell) of the calling service subscriber at invocation and group ID if the call is originated by a calling subscriber is a service subscriber;

– the addressed group call area if the call is originated by a calling dispatcher;

– the preregistered destination dispatchers related to that group call area and group ID.

The calling service subscriber or calling dispatcher shall be informed by the network with a suitable indication about the successful establishment of the voice broadcast call so that the user can start to speak.

The call can be released by the calling service subscriber or by the calling dispatcher or by the network (e.g. in case of a higher priority call) or by an entitled dispatcher predefined in the network.

Destination subscribers leaving the voice broadcast call for any reason shall not release the on going voice broadcast call.

5.5 Charging requirements

Normal event data according to 3GPP TS 32.005 shall be recorded as a network option related to calling subscriber or related to all VBS calls to one group ID in a specific group call area. . In addition data to be passed to the anchor MSC for charging purposes is the resources (i.e. cell identities) used during a call.

5.6 Security requirements

VBS shall be able to support over-the-air ciphering in order to provide confidentiality protection to group calls.

VBS ciphering is an operator’s option.

VBS shall provide means such that only a legitimate service subscriber is able to participate in a ciphered VBS call when the operator requires confidentiality protection for the group call. To include a subscriber into a ciphered voice group the required group data shall be stored on the USIM. Storing these group data on the USIM may be done e.g. during the USIM personalisation process or via OTA (over-the-air) provisioning.

A pre- Rel-6 VBS capable mobile shall be able to participate in an un-ciphered group call, if it is part of that group.