Conversational voice and audio services are among the most important ones in 3GPP mobile business. Switch from narrowband to wideband speech audio with AMR-WB is an important improvement step for these services. In order to keep high value in such services, Rel-10 and the new EPS system give an opportunity for a next major step in voice and audio enhancement, particularly for very high audio quality suited to the increasing mixed music/speech content.
The Evolved Packet System (EPS) is an evolution of the 3GPP architecture to a higher-data-rate, lower-latency packet-optimized system that supports various radio-access technologies. The EPS architecture has been optimized for mobile broadband services, in particular enriched and new multimedia services. The EPS system is an enabler for providing conversational services with very high audio quality, including enhanced voice and mixed content quality.
This document aims at studying use cases which may benefit from improved audio quality for EPS services and examining the need for enhanced codecs. The related system and service requirements are discussed.
This study defines and analyses the new use cases in the environment of EPS and its future services. It evaluates how much the newly defined requirements are met by the already available codecs in 3GPP releases prior to Rel-10. Potential new requirements for voice codecs are elaborated in due course.
Specifically, the objective of this study item is to:
Identify service and system requirements,
Identify high level requirements,
Assess the existing codecs in respect to identified requirements,
Define a strategy for EPS voice codec(s) standardization,
Identify some use cases for enhanced voice and mixed content conversational multimedia service for EPS (see Annex A).
Starting from Rel-8 timeframe, MTSI as a conversational multimedia service is provided over EPS. MTSI is the main service for which the enhancements are targeted. This does not however exclude the enhanced service requirements from being later adopted to other services where such enhancements are needed and are found suitable.