IMS (IP Multimedia Subsystem) is a 3GPP standard that was developed to support multimedia services over IP-based networks. The key points are:
- IMS was specified by 3GPP to support the evolution from circuit-switched to packet-switched networks and provide multimedia services using SIP.
- Standards bodies like ETSI, IETF, and 3GPP collaborated on IMS to develop specifications for NGN networks using SIP and Internet protocols.
- IMS aims to be compatible with Internet standards to provide access independence and interoperability. It uses SIP for session control and supports multimedia services like voice, video, and messaging over IP networks.