1 Framework for defining Circuit Bearer Services

22.0023GPPCircuit Bearer Services (BS) supported by a Public Land Mobile Network (PLMN)TS

Bearer Services are described by attributes, which are intended to be independent. These attributes are described and defined in TS 22.001 [2]. They are grouped into four categories:

i) Information transfer attributes, which characterize the network capabilities for transferring information from a user access point in a PLMN to a user access point in another network. (Refer to TS 22.001 [2] ).

ii) Access attributes, which describe the means for accessing network functions or facilities as seen at the access point in the PLMN (see TS 22.001 [2]).

iii) Interworking attributes, which describe properties of the terminating network and its access point. The terminating network may include another PLMN or the originating PLMN.

iv) General attributes, which deal with the service in general.

Figure 1 shows the relation between the groups of attributes and their fields of applicability.

NOTE 1: A transit network may not exist for a Bearer Service.

NOTE 2: Communication may be established from either end.

NOTE 3: The information transfer and access attributes of a Bearer Service relate to a direct peer-to-peer communication of:

– TE to TE;

– TE to a network gateway (supporting, for example, PSTN interworking); or

– network gateway to a TE.

Figure 1: Relation between the groups of attributes and fields of applicability

The following table lists the individual attributes in each of the four groups. The Bearer Service definitions in this specification are based on the "Minimal Set" of attributes.

Table 1: List of Bearer Service attributes

		Minimal
		Set
Information Transfer Attributes
	Information Transfer Mode	X
	Information Transfer Rate	X
	Information Transfer Capability	X
	Establishment of Communication	X
	Symmetry	X
	Communication Configuration	X
	Data Compression
Access Attributes
	Access Channel and Rate
	Signalling Access Protocols
	Information Access Protocols
	Information Access Structure	X
	Information Access Rate	X
Interworking Attributes
General Attributes
	Supplementary Services Provided
	Quality of Service	X
	Operational and Commercial

Attributes that are not part of the minimal set provide further technical detail and are required to fully define the use of each Bearer Service.

See specifications [4], [5], [6], [7] for information about the Signalling Access Protocols, Information Access Protocols and related access attributes.

Supplementary services are defined in TS 22.004 [3].

Intercommunication is required with services in the PSTN, ISDN and other PLMNs. The capabilities that describe the Interworking Attributes are described in specifications [8] to [9] and [15].