IP Multimedia Subsystem

About: IP Multimedia Subsystem is a research topic. Over the lifetime, 4398 publications have been published within this topic receiving 43698 citations.

SIP Multicast-Based Mobile Quality-of-Service Support over Heterogeneous IP Multimedia Subsystems

Abstract: The Universal Mobile Telecommunications System (UMTS) all-IP network supports IP multimedia services through the IP multimedia subsystem (IMS). This paper proposes a mobile quality-of-service (QoS) framework for heterogeneous IMS interworking. To reduce the handoff disruption time, this framework supports the IMS mobility based on the concept of session initiation protocol (SIP) multicast. In our approach, the mobility of a user equipment (UE) is modeled as a transition in the multicast group membership. With the concept of dynamic shifting of the multicast group's members, the flow of actual data packets can be switched to the new route as quickly as possible. To overcome mobility impact on service guarantees, UEs need to make QoS resource reservations in advance at neighboring IMS networks, where they may visit during the lifetime of the ongoing sessions. These locations become the leaves of the multicast tree in our approach. To obtain more efficient use of the scarce wireless bandwidth, our approach allows UEs to temporarily exploit the inactive bandwidths reserved by other UEs in the current IMS/access network. Analytic and simulation models are developed to investigate our resource reservation scheme. The results indicate that our scheme yields comparable performance to that of the previously proposed channel assignment schemes.

Trends in multimedia applications and the network models to support them

Abstract: Leading corporations and federal agencies are beginning to recognize the great potential of multimedia applications. IBM and Apple have announced major commitments to develop equipment and software for multimedia applications. Current trends in multimedia applications are examined. A summary of the network implications in view of broadband ISDN (B-ISDN) is included. Multimedia database systems; audio, video, and graphics multimedia mail; teleconferencing; video extension to the X window (VEX); and an audio server under development at Olivetti Research Center (VOX) are outlined. Handling multimedia requests, distributed computing and shared resources, media conversion, and issues of network design are discussed. >

Cross-Layer Mobility Management based on Mobile IP and SIP in IMS

Abstract: IP multimedia subsystem ( IMS ) is a new network architecture for providing multimedia service in the next generation wireless networks, 3GPP has chosen session initiated protocol ( SIP ) to be the signaling protocol in IMS. At present, IMS can only support nomadic mobility but not seamless mobility. So a new solution is required to support seamless mobility in IMS. In this paper, we proposed a new cross-layer mobility management solution based on the integration of Mobile IP and SIP. In our proposed solution, we introduce a cross-layer module between home agent and S-CSCF, which can realize information exchange between network layer and application layer. Through the cross-layer module, the binding update message received by home agent can be translated and forwarded to S-CSCF to trigger the registration procedure in IMS. So the signaling between mobile node and home network can be reduced dramatically. Finally, we analyzed our proposed three mobility management solutions theoretically and made simulations based on our analysis. The simulation results demonstrated that the cross-layer mobility management solution brings smaller handoff delay and lower signaling overhead to the network than the other two solutions. So we can conclude that cross-layer mobility management solution can provide better mobility management for real-time service in IMS and achieve good scalability.

System and method for VoIP call transfer using instant message service in an IP multimedia subsystem

Abstract: The Instant Messaging capability of an IP multimedia subsystem is utilized to support call transfer service for VoIP users. A call transfer request from a first VoIP user to a second VoIP user is sent to the IP multimedia subsystem in a predetermined non-standard SIP communication. The IP multimedia subsystem invokes Instant Messaging service in response to the predetermined non-standard SIP communication, and Instant Messaging service is then utilized to support the call transfer dialogue.

Conversational IP multimedia security

Abstract: With the introduction of 3G systems multimedia applications over wireless will become widely available to the general public. One such application will be peer-to-peer conversational multimedia communication in which voice, video, still pictures and other media can be used simultaneously and in an interactive way. However, in an all IP environment it is important to have high quality and efficient security services to protect the traffic against eavesdropping and manipulations. In particular, end-to-end security is considered attractive. This paper investigates the security requirements that emerge from conversational IP multimedia applications in heterogeneous environments, with special emphasis on the requirements stemming from the wireless access. The design and the design goals of both SRTP, a security protocol for protection of media traffic, and multimedia Internet keying (MIKEY), a key management protocol specially developed for those environments, are also described.