E.1 General
26.1143GPPIP Multimedia Subsystem (IMS)Media handling and interactionMultimedia telephonyRelease 18TS
This annex contains examples with mappings of SDP parameters to QoS parameters [64] for MTSI.
The bitrates used in these QoS examples for MBR and GBR for MBR=GBR bearers and for MBR for MBR>GBR bearers are based on the highest bitrates possible with the codecs, profiles and levels defined in Clause 5.2. The bitrates used for GBR for MBR>GBR bearers are chosen to still give usable quality levels.
The ‘a=bw-info’ attributed defined in Clause 19 can be used to provide additional bandwidth information for the setting of MBR and GBR and also to align the resource allocation end-to-end, see also Clauses 6.2.5 and 6.2.7.
The bearer setup also depends on the outcome of the SDP offer-answer negotiation. The QoS profiles shown below assume that both end-points agree on using the codecs and bitrates as described in each respective example.
The QoS Class Identifier (QCI) [90] and 5G QoS Indentifier (5QI) [176] are used to describe the packet forwarding treatment for different media types. The table below gives a few examples for how the QCI/5QI can be set for different media types.
Table E.0: Example mapping between media type and QCI.
|
Media |
Bearer type |
QCI/5QI |
|
Speech |
Dedicated GBR bearer |
1 |
|
Video (conversational) |
Dedicated GBR bearer |
2 |
|
Video (non-conversational) |
Dedicated GBR bearer |
4 |
|
Dedicated non-GBR bearer or default non-GBR bearer |
6, 8 or 9 |
|
|
Real-time text |
Dedicated non-GBR bearer or default non-GBR bearer |
6, 8 or 9 |
|
Data channel |
Dedicated GBR or non-GBR, or default non-GBR bearer |
71, 72, 73, 74, 76, or 9 |
This mapping assumes that the QCIs are used as described in TS 23.203, Table 6.1.7, [90] for LTE access, and 5QIs as described in TS 23.501, Table 5.7.4-1 [176] for NR access.
.