E.2 Bi-directional speech (AMR12.2, IPv4, RTCP and MBR=GBR bearer)
26.1143GPPIP Multimedia Subsystem (IMS)Media handling and interactionMultimedia telephonyRelease 18TS
The bitrate for AMR 12.2 including IP overhead (one AMR frame per RTP packet, using bandwidth efficient mode) is 28.8 kbps which is rounded up to 29 kbps. IPv4 is also assumed.
Table E.1: QoS mapping for bi-directional speech (AMR 12.2, 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 speech services |
|
Transfer delay (ms) |
130 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) |
31 |
The total bit-rate of AMR12.2 including IP/UDP/RTP overhead and 5 % for RTCP. |
|
Maximum bitrate for uplink (kbps) |
31 |
The same as the guaranteed bitrate. |
|
Guaranteed bitrate for downlink (kbps) |
31 |
The total bit-rate of AMR12.2 including IP/UDP/RTP overhead and 5 % for RTCP. |
|
Maximum bitrate for downlink (kbps) |
31 |
The same as the guaranteed bitrate |
|
Allocation/Retention priority |
subscribed value |
Indicates the relative importance to other radio access bearers. It should be the next lower value to the priority of the signalling bearer. |
|
Source statistics descriptor |
‘speech’ |