ABSTRACT

IP multimedia subsystem (IMS) is an architectural framework for delivering multimedia services standardized by the Third-Generation Partnership (3GPP/3GPP2) in late 1999. IMS enables multimedia and voice services to be delivered in a well-structured manner. It facilitates services integration over disparate networks, including the Internet and cellular networks. IMS enables advanced services such as email, video conference, presence, chat, push to talk (PTT), and IPTV to become widely available to the users.