scope:

This Recommendation defines mechanisms/auxiliary functions for a signal processing network equipment (SPNE) designed for the use in the circuit switched part of a network (mobile, fixed and hybrid). The SPNE addressed in this Recommendation is a physical entity that contains one or more of the following signal processing functions (SPFs) optimized for speech quality, acoustic echo control, electric echo cancellation, noise reduction and automatic level control. The SPNE can be designed as stand-alone equipment or can be integrated in some other network equipment. The SPNE provides the SPFs permanent associated to the circuits or arranged in a pool. Depending on where in the network the SPNE is going to be provided, the mechanisms/auxiliary functions identified in this Recommendation include appropriate interfaces to allow external control of the SPFs and the support of in-band signalling such as tandem free operation (TFO) and of services such as high speed circuit switched data (HSCSD).