as the same technical features as the AMR codec and improves voice quality by increasing the bandwidth (50-7000 Hz) for the audio signal. Several configurations (A, B, C) and several rates per configuration are defined: - configuration A: 6.6 kbps, 8.85 kbps and 12.65 kbps; - configuration B: 6.6kbps, 8.85 kbps, 12.65 kbps and 15.85 kbps; - configuration C: 6.6 kbps, 8.85 kbps, 12.65 kbps and 23.85 kbps. The SDP offer is more important because it must include the AMR and AMR-WB codecs and can propose, for each type of codec, both formats: - the values 97 and 99 of the Payload Type field correspond to the bandwidth-efficient format for AMR-WB and AMR codecs; - the values 98 and 100 of the payload type field correspond to the byte- aligned format for AMR-WB and AMR codecs. The values 97 and 98 of the payload type field are listed first because the AMR-WB codec has priority over the AMR codec. Service Profiles m=audio 49152 RTP/AVP 97 98 99 100 a=rtpmap : 97 AMR-WB/16000/1 a=rtpmap 98 AMR-WB/16000/1 a=fmtp: 98 octet-align=1 a=rtpmap : 99 AMR/8000/1 a=rtpmap : 100 AMR/8000/1 a=fmtp : 100 octet-align=1 5.2.2.3. EVS codec The EVS concept is a new family of codecs whose different types depend on the bandwidth of the audio signal: - Narrow band (NB), for an audio signal whose bandwidth is 300-3400 - Wide band (WB), for an audio signal whose bandwidth is 50-7000 Hz; - Super wide band (SWB), for an audio signal whose bandwidth is 50- 14000 Hz; - Full band (FB), for an audio signal whose bandwidth is 20-20000 Hz. The flow rates obtained have the following values: 5.9 kbps, 7.2 kbps, 8 kbps, 9.6 kbps, 13.2 kbps, 16.4 kbps, 24.4 kbps, 32 kbps, 48 kbps, 64 kbps, 96 kbps and 128 kbps. The rate for the NB type is in the range between 5.9 and 24.4 kbps. The rate for the WB type is in the range between 5.9 and 128 kbps. The rate for the SWB type is in the range between 9.6 and 128 kbps. The rate for the SWB type is in the range between 16.4 and 128 kbps. The NB-type and WB-type EVS codecs provide the following improvements compare