For the purposes of the present document, the following terms and definitions apply:
Network operator:
Entity which provides the network operating elements and resources for the execution of the VBS.
Service provider:
Entity which offers the VBS for subscription. The network operator may be the service provider.
Service subscriber:
Mobile subscriber which subscribes to the VBS.
Voice broadcast call:
An instance of the VBS initiated by a VBS subscriber. This term is used synonymously with the term "VBS call".
Group identification (group ID):
A numerical classification. The maximum number of group Ids which can be defined in one PLMN depends on the maximum number of group call areas defined in this PLMN. The maximum number of group Ids and group call areas shall be 108, Service subscriber shall be provided with one or up to 50 group Ids.
Dispatcher:
Particular fixed line or mobile users are identified within the network as dispatchers. Dispatchers shall receive all voice broadcast calls to a certain group ID in a group call area (this shall be done automatically by the network). In addition they can initiate voice broadcast calls to a group ID in a group call area.
Dispatchers shall be connected to a voice broadcast call by means of standard links via radio or via an ISDN. They shall be called by their MSISDN or ISDN number, respectively. When dispatchers initiate voice broadcast calls, they shall call a particular MSISDN number which is related to a group ID and group call area. Dispatchers using the GSM network can be located outside of this group call area.
The identities of the dispatchers are exclusively predefined in the network by the service provider. There may be none, one or more dispatchers involved in a particular voice broadcast call.
As a mandatory network requirement, configuration of up to 5 dispatchers shall be supported. Optionally, up to a maximum of 20 dispatchers may be configured for a particular group call reference.
Destination service subscriber:
Service subscriber to which the VBS call is directed.
Calling service subscriber:
Service subscriber which originates the VBS call.
Calling dispatcher:
Dispatcher which originates the VBS call.
Destination dispatcher:
Pre-registered dispatcher to which the VBS call is directed.
Destination subscriber:
Destination dispatcher(s) and/ or destination service subscriber(s) to which the VGCS call is directed.
Group call area:
Predefined area composed of one or a cluster of cells, to which a particular VBS call is distributed. The maximum number of group call area Ids which can be defined in one PLMN depends on the maximum number of group Ids defined in this PLMN. The maximum number of group Ids and group call areas combined shall be 108, The composition of a group call area is predefined in the network by the service provider. Changing of cell allocations in the network due to operational reasons will need an adaptation of the group call area definition. The group call area may include cells of more then one MSC area and cells of more than one PLMN.
Originator-to-dispatcher information:
Information sent by the service subscriber originating a voice group call to the network during call setup for distribution to the dispatchers to be attached to the group call during call setup.
Listener:
see Listening service subscriber
Listening service subscriber:
Service subscriber who is listening to an ongoing voice group call.
Abbreviations used in the present document are listed in
TR 21.905.