Patent ID: 7764953
Filing Date: 2010-07-27
Classification: H04M,H04W

Abstract:
1. A method for speech Codec negotiation in a communication system, comprising: receiving, by a mobile switching center emulation in the communication system, an originating call signal from a calling user, the originating call signal carrying a number of a called mobile station; obtaining a latest speech Codec list used by the called mobile station from a database storing mobile station information in accordance with the number of the called mobile station; obtaining, by the mobile switching center emulation, a speech Codec list supported by the calling user; and determining a speech Codec to be used in a communication between the calling user and the called mobile station, in accordance with the speech Codec list supported by the calling user and the latest speech Codec list used by the called mobile station; wherein obtaining the speech Codec list supported by the calling user comprises: requesting, by the mobile switching center emulation, the calling user to send the speech Codec list supported by the calling user through an Assignment Request message; receiving, by the mobile switching center emulation, the speech Codec list supported by the calling user returned by the calling user through an Assignment Complete message; and wherein when the called mobile station performs a voice communication, the speech Codec list used by the called mobile station is stored in the database, and only a latest speech Codec list used by the mobile station is stored; wherein the step of determining a speech Codec to be used in a communication between the calling user and the called mobile station comprises: obtaining speech Codecs in an intersection set between the latest speech Codec list used by the called mobile station and the speech Codec list supported by the calling user; and choosing the speech Codec to be used in the communication between the calling user and the called mobile station from the intersection set, wherein when the intersection set between the latest speech Codec list used by the called mobile station and the speech Codec list supported by the calling user contains a speech Codec preferred by the calling user or the called mobile station, the speech Codec is chosen in precedence.