VoIP Voice and Fax Signal Processing

9.3 WIDEBAND VOICE SUMMARY

Wideband telephones are not widely available currently. Several conference phones are available in wideband, but they are expensive. It may take some time to get these phones at the right price. With VoIP expanding in scope through various convergence operations of IMS, FMC, and other extensions, wideband may gain more access to users. Deployment boxes are incorporating the wideband-capable hardware devices, and they can work with simple software configurations.

The IP phone is a single channel processing system with three-way conferencing. The processing power should be sufficient with wideband. In VoIP adapters, one to four channels are used. It is required to cater to extra voice processing in these devices. The wideband total voice chain is expected to consume about 50% to 100% more processing depending on the codec. The codecs like G.729.1, and G.722.2 take more processing power. The waveform-based G.722 takes lower processing than does the narrowband G.729A codec. In the process of an end-to-end call, if the narrowband codec is used at any intermediate stage, there is no real benefit of using wideband. An end-to-end wideband call is the way to exceed PSTN voice quality. It is expected that wideband voice coexists with several multimedia services through an IP network.

VoIP Voice and Fax Signal Processing, by Sivannarayana NagireddiCopyright © 2008 by John Wiley & Sons, Inc.