【資料名稱】：Adaptive Multi Rate Wide Band High Definition Voice

【資料作者】：AMR-WB Presentation

【資料日期】：2012-12-20

【資料語(yǔ)言】：英文

【資料格式】：PPT

【資料目錄和簡(jiǎn)介】：

Adaptive Multi Rate Wideband (AMR-WB) is a speech and channel codec for full rate GERAN channels and UTRAN defined by 3GPP and ITU-T, with four different codec types.

By adapting the codec rate to the radio conditions the speech quality is enhanced. At low C/I, a large amount of channel coding is applied and less speech coding. When the C/I increases the speech coding is increased and the channel coding is decreased.

AMR-WB requires support in all network nodes, that is MSC/MGw, BSC, BTS and MS. AMR-WB is supported when all TRXs within one channel group are AMR-WB capable.
The AMR WB gives a clearly improved speech quality for mobile-to-mobile calls compared to FR, EFR and AMR NB coded speech. A prerequisite for the improved speech quality is that TFO or TrFO are used for the call. With TFO/TrFO the speech frames are sent transparently between the UEs without any transcoding in the CN. TFO still requires transcoding hardware, while TrFO eliminates even that need.