5 Bearer Capabilities for UMTS Data Services

23.2023GPPCircuit switched data bearer servicesRelease 17TS

The UMTS bearer services are described by the PLMN BC-IE. Five services (or services categories) are currently distinguishable from the PLMN BC-IE in UTRAN Iu mode:

– Speech.

– Transparent Data for support of Multimedia.

– Transparent Data.

– Non-transparent Fax.

– Non-transparent data.

Four services (or services categories) are currently distinguishable from the PLMN BC-IE in GERAN Iu mode:

– Speech.

– Transparent Data for support of Multimedia.

– Transparent Data.

– Non-transparent data.

Speech is currently not in the scope of the present document.

Each UMTS bearer service is supported by a Radio Access Bearers (RAB). The RABs in turn are described by the QoS parameters. There may be one or several RAB candidates for supporting a UMTS bearer service. The possible candidates are described by a mapping of the BC-IE to RAB QoS described in subclause 5.2.

5.1 Bearer Capabilities for UMTS Data Services

5.1.1 Transparent Data

This service is distinguished by the following BC-IE parameters:

– ITC = UDI or 3.1 kHz audio or Other ITC = RDI.

– CE = transparent.

For this service the FNUR at the setup is restricted to:

– 64 kbit/s, in case ITC = UDI.

– 56 kbit/s in case ITC = UDI or Other ITC = RDI.

– 28,8 kbit/s, in case ITC = 3,1 kHz audio.

NOTE: ITU-T Recommendation V.90 [16] is not supported in transparent mode, because asymmetric user rates are not supported in transparent mode.

5.1.2 Non-Transparent Fax

This service is only applicable for UTRAN Iu mode. It is distinguished by the following BC-IE parameters:

– ITC = Fax Group 3 (ITU-T Recommandation T.30 [17]).

– CE = non-transparent.

WAIUR shall not be more than 28.8 kbit/s. The possible AIURs are limited to 14,4 kbit/s and 28,8 kbit/s.

5.1.3 NT Data

This service is distinguished by the following BC-IE parameters:

– ITC = UDI or 3.1 kHz audio or Other ITC = RDI.

– CE = non-transparent.

The possible AIURs in UTRAN Iu mode are limited to 14,4 kbit/s, 28,8 kbit/s and 57,6 kbit/s. For GERAN Iu mode the following AIURs are possible: 9,6 kbit/s, 14,4 kbit/s, 19,2 kbit/s, 28,8 kbit/s, 38,4 kbit/s, 43,2 kbit/s and 57,6 kbit/s.

5.1.4 Transparent Data for Support of Multimedia

This service is distinguished by the following BC-IE parameters:

– ITC = UDI or 3.1 kHz audio or Other ITC = RDI.

– CE = transparent.

– Other rate adaptation = H.223 and H.245.

For this service the FNUR at the setup is restricted to:

– 64 kbit/s, in case ITC = UDI.

– 56 kbit/s in case Other ITC = RDI.

– 33,6 kbit/s, in case ITC = 3,1 kHz audio.

– 32 kbit/s, in case ITC = UDI.

– 28,8 kbit/s, in case ITC = 3,1 kHz audio.

NOTE: Transmission rates 31.2 kbit/s and 28.8 kbit/s negotiated by the modems in a 3.1 kHz multimedia call may be used with a rate adaptation to 33.6 kbit/s between the UE and the IWF (see 3GPP TS 27.001 [14] and 3GPP TS 29.007 [15]). The negotiated values shall be provided by the MSC by way of a MODIFY message.

5.2 BC-IE to RAB QoS Mapping

Since UMTS bearer services are described by BC-IEs and RABs by QoS parameters, a mapping between the UMTS bearer services and the possible RABs that support them has to be specified. The QoS mapping is based on 3GPP TS 23.107 [10] and is specified in detail in 3GPP TS 27.001[14], annex B, subclause B.1.13.