A METHOD AND COMMUNICATION SYSTEM FOR THE CS DOMAIN USER ACCESSING THE IMS DOMAIN

摘要

A method for the CS domain user accessing the IMS domain comprises: the AGCF entity maps the CS domain signaling message forwarded by MSC/VLR to the signaling message of SIP, and transmits the signaling message to the AGCF entity of the IMS domain; the AGCF entity maps the signaling message of SIP transmitted from the IMS domain to CS domain to the signaling message of the CS domain, and transmits to MSC/VLR. The present invention also discloses a communication and an AGCF entity. Comparing with the prior art, the invention makes less workload of the upgrade and the reconstruction for the present capacity network, and applies to the users of the R99 CS domain and CS domain that the version is before R99 to access the IMS domain.