E.21 Bi-directional video (H.264 AVC level 1.2, IPv4, RTCP and MBR>GBR bearer)
26.1143GPPIP Multimedia Subsystem (IMS)Media handling and interactionMultimedia telephonyRelease 18TS
The video bandwidths used for defining MBR and GBR are assumed to be 384 kbps and 192 kbps, respectively. The IPv4 overhead is 20 kbps (assuming 15fps and 4 IP packets per frame) for MBR and 10 kbps (assuming 15 fps and 2 IP packets per frame) for GBR, resulting in 404 kbps and 202 kbps, respectively. The transfer delay for video is different from other media. The applicable H.264 profile level can be derived from the "profile-level-id" MIME parameter signalled within the SDP "a=fmtp" attribute. H.264 receivers can request to receive only a lower bandwidth than depicted in this example via the SDP "b:AS" parameter.
Table E.22: QoS mapping for bi-directional video (H.264 AVC level 1.2, IPv4, RTCP and MBR>GBR bearer)
|
Traffic class |
Conversational class |
Notes |
|
Delivery order |
No |
The application should handle packet reordering. |
|
Maximum SDU size (octets) |
1400 |
Maximum size of IP packets |
|
Delivery of erroneous SDUs |
No |
|
|
Residual BER |
10-5 |
Reflects the desire to have a medium level of protection to achieve an acceptable compromise between packet loss rate and speech transport delay and delay variation. |
|
SDU error ratio |
7*10-3 |
A packet loss rate of 0.7 % per wireless link is in general sufficient for video services |
|
Transfer delay (ms) |
170 ms |
Indicates maximum delay for 95th percentile of the distribution of delay for all delivered SDUs between the UE and the PS domain during the lifetime of a bearer service. Permits the derivation of the RAN part of the total transfer delay for the radio access bearer. This attribute allows RAN to set transport formats and H-ARQ/ARQ parameters such as the discard timer. |
|
Guaranteed bitrate for uplink (kbps) |
208 |
The total bit-rate of a video codec (running at 192 kbps) adding IP/UDP/RTP overhead (assumed to be 10 kbps) and RTCP (RS:0 and RR:5000 used in clause A.6 adds 2.5kbps). The value is then rounded up to nearest multiple of 8 kbps. It is up to MTSI implementations or network policies to use higher GBR values. |
|
Maximum bitrate for uplink (kbps) |
408 |
The total bit-rate of a video codec (running at 384 kbps) adding IP/UDP/RTP overhead (assumed to be 20 kbps) and RTCP (RS:0 and RR:5000 used in clause A.6 adds 2.5kbps). The value is then rounded up to nearest multiple of 8 kbps. If downlink SDP contains a lower b:AS bandwidth modifier value, this should be used instead. |
|
Guaranteed bitrate for downlink (kbps) |
208 |
The total bit-rate of a video codec (running at 192 kbps) adding IP/UDP/RTP overhead (assumed to be 10 kbps) and RTCP (RS:0 and RR:5000 used in clause A.6 adds 2.5kbps). The value is then rounded up to nearest multiple of 8 kbps. It is up to MTSI implementations or network policies to use higher GBR values. |
|
Maximum bitrate for downlink (kbps) |
408 |
The total bit-rate of a video codec (running at 384 kbps) adding IP/UDP/RTP overhead (assumed to be 20 kbps) and RTCP (RS:0 and RR:5000 used in clause A.6 adds 2.5kbps). The value is then rounded up to nearest multiple of 8 kbps. If uplink SDP contains a lower b:AS bandwidth modifier value, this should be used instead. |
|
Allocation/Retention priority |
subscribed value |
Indicates the relative importance to other radio access bearers. It should be the same or next lower value to the priority of a Conversational bearer with source statistics descriptor ‘speech’. |
|
Source statistics descriptor |
‘unknown’ |