Content for TS 26.114 Word version: 18.8.0

0… 3… 4… 5… 6… 6.2.3… 6.2.5… 6.2.7… 6.2.10… 7… 7.5… 8… 9… 10… 10.2.1.6… 10.2.2… 10.3… 10.4… 11… 12… 12.3… 12.7… 13a… 16… 16.5… 17… 18… 19… A… A.3… A.4… A.5… A.10… A.14… A.15… B… C… C.1.3… C.1.3.5 C.2… D E… E.18… E.31… G… K… L… M… N… O… P… P.3 Q… R… S… T… U… V… W… X… Y… Y.6… Y.6.4… Y.6.5… Y.7…

Q.1 General Q.2 Procedure for computing the bandwidth Q.3 Computation of RTP payload size Q.4 Detailed computation
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Q Computation of b=AS for EVS |R12| p. 421

Q.1 General p. 421

This Annex contains examples of computing b=AS for EVS Primary mode when ptime=20, and ptime=40. In these examples, it is assumed that no extra bandwidth is allocated for redundancy.

Q.2 Procedure for computing the bandwidth p. 421

The bandwidth is calculated using the following procedure when no extra bandwidth is allocated for redundancy:

Calculate the size of the RTP payload, see below.
Calculate the size of the IP packets by taking the RTP payload size (in bytes) and adding the IP/UDP/RTP overhead: 20 bytes for IPv4; 40 bytes for IPv6; 8 bytes for UDP; 12 bytes for RTP.
Convert the IP packet size to bits.
Calculate the required bit-rate (bps) given the packet size and the packet rate: 50 packets per second for 1 frame per packet; 25 packets per second for 2 frames per packet.
The b=AS bandwidth is then calculated by converting the required bit-rate to kbps and rounding to the nearest higher integer value.

If the SDP includes multiple codecs and/or configurations, the bandwidth is calculated for each configuration and the b=AS bandwidth is set to the highest of the bandwidths.

Q.3 Computation of RTP payload size p. 421

When the b=AS bandwidth is computed, it is assumed that the codec is using the highest allowed bit-rate for each frame.

The RTP payload size for the 2 bytes header-full payload format and 1 frame/packet is calculated from the following components:

8 bits for the codec mode request (CMR)
8 bits for the table of content (ToC)
N bits for the speech frame (size depends on bit-rate)
No padding in the end of the RTP payload is needed since each item is already an integer number of octets

The RTP payload size for the 2 bytes header-full payload format and 2 frames/packet is calculated from the following components:

8 bits for the codec mode request (CMR)
16 bits for the table of content (ToC)
N bits for the speech frame (size depends on bit-rate)
No padding in the end of the RTP payload is needed since each item is already an integer number of octets

Q.4 Detailed computation p. 422

The Tables below give a detailed description of the bandwidth computation. The b=AS bandwidth is not defined for SID.

For each codec mode, b=AS value of EVS AMR-WB IO mode is the same as the b=AS value of AMR-WB in octet-aligned mode. See clause K.4.

Table Q.1: Computation of b=AS for EVS Primary mode (IPv4, ptime=20)

Mode	7.2	8	9.6	13.2	16.4	24.4	32	48	64	96	128	SID
Bits per speech frame	144	160	192	264	328	488	640	960	1280	1920	2560	48
Speech frame size (bytes)	19	20	24	33	41	61	80	120	160	240	320	6
CMR and ToC (bits)	16	16	16	16	16	16	16	16	16	16	16	16
RTP payload (bits)	168	176	208	280	344	504	656	976	1296	1936	2576	64
RTP header (bits)	96	96	96	96	96	96	96	96	96	96	96	96
UDP header (bits)	64	64	64	64	64	64	64	64	64	64	64	64
IPv4 header (bits)	160	160	160	160	160	160	160	160	160	160	160	160
Total bits per 20 ms	488	496	528	600	664	824	976	1296	1616	2256	2896	384
Total bit-rate (kbps)	24.4	24.8	26.4	30	33.2	41.2	48.8	64.8	80.8	112.8	144.8	19.2
AS (kbps)	25	25	27	30	34	42	49	65	81	113	145	N/A

Table Q.2: Computation of b=AS for EVS Primary mode (IPv6, ptime=20)

Mode	7.2	8	9.6	13.2	16.4	24.4	32	48	64	96	128	SID
Bits per speech frame	144	160	192	264	328	488	640	960	1280	1920	2560	48
Speech frame size (bytes)	19	20	24	33	41	61	80	120	160	240	320	6
CMR and ToC (bits)	16	16	16	16	16	16	16	16	16	16	16	16
RTP payload (bits)	168	176	208	280	344	504	656	976	1296	1936	2576	64
RTP header (bits)	96	96	96	96	96	96	96	96	96	96	96	96
UDP header (bits)	64	64	64	64	64	64	64	64	64	64	64	64
IPv6 header (bits)	320	320	320	320	320	320	320	320	320	320	320	320
Total bits per 20 ms	648	656	688	760	824	984	1136	1456	1776	2416	3056	544
Total bit-rate (kbps)	32.4	32.8	34.4	38	41.2	49.2	56.8	72.8	88.8	120.8	152.8	27.2
AS (kbps)	33	33	35	38	42	50	57	73	89	121	153	N/A

Table Q.3: Computation of b=AS for EVS Primary mode (IPv4, ptime=40)

Mode	7.2	8	9.6	13.2	16.4	24.4	32	48	64	96	128
Bits per speech frame	144	160	192	264	328	488	640	960	1280	1920	2560
Speech frame size (bytes)	18	20	24	33	41	61	80	120	160	240	320
CMR and ToC (bits)	24	24	24	24	24	24	24	24	24	24	24
RTP payload (bits)	312	344	408	552	680	1000	1304	1944	2584	3864	5144
RTP header (bits)	96	96	96	96	96	96	96	96	96	96	96
UDP header (bits)	64	64	64	64	64	64	64	64	64	64	64
IPv4 header (bits)	160	160	160	160	160	160	160	160	160	160	160
Total bits per 40 ms	632	664	728	872	1000	1320	1624	2264	2904	4184	5464
Total bit-rate (kbps)	15.8	16.6	18.2	21.8	25	33	40.6	56.6	72.6	104.6	136.6
AS (kbps)	16	17	19	22	25	33	41	57	73	105	137

Table Q.4: Computation of b=AS for EVS Primary mode (IPv6, ptime=40)

Mode	7.2	8	9.6	13.2	16.4	24.4	32	48	64	96	128
Bits per speech frame	144	160	192	264	328	488	640	960	1280	1920	2560
Speech frame size (bytes)	18	20	24	33	41	61	80	120	160	240	320
CMR and ToC (bits)	24	24	24	24	24	24	24	24	24	24	24
RTP payload (bits)	312	344	408	552	680	1000	1304	1944	2584	3864	5144
RTP header (bits)	96	96	96	96	96	96	96	96	96	96	96
UDP header (bits)	64	64	64	64	64	64	64	64	64	64	64
IPv6 header (bits)	320	320	320	320	320	320	320	320	320	320	320
Total bits per 40 ms	792	824	888	1032	1160	1480	1784	2424	3064	4344	5624
Total bit-rate (kbps)	19.8	20.6	22.2	25.8	29	37	44.6	60.6	76.6	108.6	140.6
AS (kbps)	20	21	23	26	29	37	45	61	77	109	141

Table Q.5: Computation of b=AS for EVS Primary mode (IPv4, ptime=20, dual-mono)

Mode	7.2	8	9.6	13.2	16.4	24.4	32	48	64	96	128
Bits per speech frame	144	160	192	264	328	488	640	960	1280	1920	2560
Speech frame size (bytes)	18	20	24	33	41	61	80	120	160	240	320
CMR and ToC (bits)	24	24	24	24	24	24	24	24	24	24	24
RTP payload (bits)	312	344	408	552	680	1000	1304	1944	2584	3864	5144
RTP header (bits)	96	96	96	96	96	96	96	96	96	96	96
UDP header (bits)	64	64	64	64	64	64	64	64	64	64	64
IPv4 header (bits)	160	160	160	160	160	160	160	160	160	160	160
Total bits per 20 ms	632	664	728	872	1000	1320	1624	2264	2904	4184	5464
Total bit-rate (kbps)	31.6	33.2	36.4	43.6	50	66	81.2	113.2	145.2	209.2	273.2
AS (kbps)	32	34	37	44	50	66	82	114	146	210	274

Table Q.6: Computation of b=AS for EVS Primary mode (IPv6, ptime=20, dual-mono)

Mode	7.2	8	9.6	13.2	16.4	24.4	32	48	64	96	128
Bits per speech frame	144	160	192	264	328	488	640	960	1280	1920	2560
Speech frame size (bytes)	18	20	24	33	41	61	80	120	160	240	320
CMR and ToC (bits)	24	24	24	24	24	24	24	24	24	24	24
RTP payload (bits)	312	344	408	552	680	1000	1304	1944	2584	3864	5144
RTP header (bits)	96	96	96	96	96	96	96	96	96	96	96
UDP header (bits)	64	64	64	64	64	64	64	64	64	64	64
IPv6 header (bits)	320	320	320	320	320	320	320	320	320	320	320
Total bits per 20 ms	792	824	888	1032	1160	1480	1784	2424	3064	4344	5624
Total bit-rate (kbps)	39.6	41.2	44.4	51.6	58	74	89.2	121.2	153.2	217.2	281.2
AS (kbps)	40	42	45	52	58	74	90	122	154	218	282