T.1 General
26.1143GPPIP Multimedia Subsystem (IMS)Media handling and interactionMultimedia telephonyRelease 18TS
T.1.1 Introduction
This annex gives a few examples of media portions from possible SDP offers and answers involving an MSMTSI client and/or MSMTSI MRF. It is not feasible to cover all possible variants of different communication scenarios and MSMTSI capabilities and hence these examples should be regarded as just a few examples of many possible alternatives. For brevity, these examples do not make use of all functionality (like robustness etc) or list all codecs that could be used in a real SDP offer/answer, and for the same reason also limits the number of supported streams compared to what could be used in a real SDP offer/answer.
T.1.2 Quality of Service examples
This clause describes how the QoS bandwidth is reserved for MMCMH sessions based on the codec and bandwidth information in the SDP answer, the number of conference participants, and the topology of the multi-party session.
When determining the QoS bandwidth to reserve for the MMCMH session, the SDP answer is examined for the following:
– When simulcast is included, the bandwidth reserved for the transmission of the media (on either the uplink or downlink) is enough to cover the simulcast. If multiple media formats are sent concurrently then the reserved bandwidth is enough to carry the sum of their bandwidth requirements. If media formats are sent alternatively, then the reserved bandwidth is enough to carry the bandwidth requirements of the highest codec rate that can be used.
– If multiple active media lines are included, the reserved bandwidth is enough to carry the sum of the bandwidth requirements of each active media line.
Table T.0 provides examples of the QoS bandwidth that could be reserved for the example SDP answers listed in the rest of this Annex.
Table T.0: Example QoS bandwidth reservations for example SDP answers
|
Table in Annex which has the example SDP answer |
Uplink GBR (kbps) |
Uplink MBR (kbps) |
Dowlink GBR (kbps) |
Downlink MBR (kbps) |
Comments |
|
T.2 |
452.5 |
452.5 |
Assumed PCC chose symmetric QoS for DL |
||
|
T.3 |
2105 |
2590 |
Assumed PCC chose symmetric QoS for DL |
||
|
T.4 |
1865 |
1865 |
Estimating QoS for MSMTSI terminal’s links, assumed PCC chose symmetric QoS for DL |
||
|
T.6 |
118 |
118 |
133.5 |
133.5 |
Can not assume symmetric because simulcast is on uplink. Assuming GBR= MBR for speech, but can set GBR lower if PCRF looks at codec-specific parameters and determines the lowest operating rate of the codecs |
|
T.9 |
118 |
118 |
194 |
194 |
Can not assume symmetric because simulcast is on uplink. Assuming GBR= MBR for speech, but can set GBR lower if PCRF looks at codec-specific parameters and determines the lowest operating rate of the codecs |
|
T.10 |
118 |
118 |
133.5 |
133.5 |
Can not assume symmetric because simulcast is on uplink. Assuming GBR= MBR for speech, but can set GBR lower if PCRF looks at codec-specific parameters and determines the lowest operating rate of the codecs |