E.32 Bi-directional speech (EVS 24.4, IPv4, RTCP and MBR=GBR bearer)
26.1143GPPIP Multimedia Subsystem (IMS)Media handling and interactionMultimedia telephonyRelease 18TS
The bit-rate for EVS 24.4 including IP overhead (one EVS frame per RTP packet, using Header-Full format) is 41.2 kbps which is rounded up to 42 kbps. IPv4 is assumed.
Table E.33: QoS mapping for bi-directional speech (EVS 24.4, 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 bit-rate for uplink (kbps) |
44 |
The total bit-rate of EVS 24.4 including IP/UDP/RTP overhead and 2000 bps for RTCP. |
Maximum bit-rate for uplink (kbps) |
44 |
The same as the guaranteed bit-rate. |
Guaranteed bit-rate for downlink (kbps) |
44 |
The total bit-rate of EVS 24.4 including IP/UDP/RTP overhead and 2000 bps for RTCP. |
Maximum bit-rate for downlink (kbps) |
44 |
The same as the guaranteed bit-rate. |
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’ |
NOTE: Residual BER and SDU error ratio of EVS are for further study.