ITU-T P.311 PDF

This Recommendation provides audio performance requirements and test methods for digital handset and headset telephones capable of transmitting an audio bandwidth extending beyond the conventional telephony bandwidth of 300 Hz to 3400 Hz, to a bandwidth of approximately 100 Hz to 8000 Hz. Such telephones are known as wideband audio telephones, and will make use of digital encoding schemes such as in [ITU-T G.722]. IP terminals may support other coding algorithms. Wideband audio telephones are expected to be used in new services such as high quality audio conferencing, video conferencing and multimedia applications.

The requirements listed in this Recommendation are primarily applicable to telephones using ITU-T G.722 encoding at 64 kbit/s, but should also be used as the basis of requirements for other wideband audio encoding schemes. This is still under study in ITU-T.

Conventional telephone band (300 Hz-3400 Hz) digital handset telephones using encoding according to [ITU-T G.711] and [ITU-T G.726] are covered by [ITU-T P.310].