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.

Voice and Internet Multimedia in UMTS Networks

Abstract: Voice telephony is the predominant service on today's cellular mobile networks, in terms of number of customers, revenues and network usage. However, it is difficult to predict how long this will be the case given the rising demand for new Internet multimedia services. It is therefore essential that 3rd generation (3G) mobile networks support a voice telephony service, but also that these networks are also capable of providing Internet multimedia services using the same technology. This paper provides an overview of how voice telephony is provided in the initial phase of the universal mobile telecommunications system (UMTS). It then describes how this is expected to evolve in later phases — so that voice telephony becomes one of a large number of multimedia services provided from a common Internet protocol-based mobile network.

Ims network system and data restore method

Abstract: A subscriber data restoring type IMS (IP Multimedia subsystem) network system includes a P-CSCF (Proxy Call Session Control Function) connected to a SIP (Session Initiation Protocol) terminal as a subscriber terminal via an access network; a S-CSCF (Serving Call Session Control Function) located within a service provision area of a provider to which the SIP terminal subscribes; and a HSS (Home Subscriber Server) storing user subscription information. The S-CSCF transmits a SIP RESET signal to the P-CSCF neighboring thereto when losing subscriber data acquired by registration processing; receives a SIP REGISTER signal transmitted by the P-CSCF in response to the SIP RESET signal; and performs re-registration processing according to the received SIP REGISTER signal to restore the lost subscriber data from the HSS.

OpenEPC: A Technical Infrastructure for Early Prototyping of NGMN Testbeds

Abstract: The challenging and ever increasing requirements of future applications demand new concepts for better control and management of network resources. The Third Generation Partnership Project (3GPP) introduced in their latest specifications the Evolved Packet Core (EPC) architecture for transparently unifying the parameters of different technologies, like the UMTS, WLAN, non-3GPP access technologies and a future Evolved Radio Access Network, called Long Term Evolution (LTE), with the use of multiple application platforms such as IP Multimedia Subsystem (IMS) and the Internet. This paper describes a testbed implementation of the Evolved Packet Core named OpenEPC which provides a reference implementation of 3GPP’s EPC developed by the Fraunhofer Institute FOKUS. OpenEPC is a set of software components offering advanced IP mobility schemes, policy-based QoS control, and integration with different application platforms in converging network environments. This initiative, in addition to fostering research and development, enables academic and industry researchers to rapidly realize state-of-the-art NGMN infrastructures and application testbeds.

Integrated management architecture for IP-based networks

Abstract: IP telephony will bring about a dramatic change in the way IP services are planned, provisioned, managed, and billed. In order to build and retain a strong customer base for these new services, service providers need to meet, if not exceed, the customer expectations set by today's traditional voice services. Acceptance of IP telephony will depend on the quality and efficiency with which service providers offer, deliver, and manage IP services. Installation, configuration, and activation must be rapid and error-free. Furthermore, customers will want direct control over the reconfiguration of services and real-time visibility into the impact change has on their operating costs. Once the service is activated, customers will want the provider to guarantee service quality as defined by industry standards. Corporate customers in particular will need to be assured that the provider is proactively monitoring performance to avoid problems and providing them visibility into the performance data collected. This article discusses an integrated management support system for IP-based networks illustrating the functions needed to support the unique challenges of managing VoIP services. An example of a service management system is also described.

System and method for inbound roaming in ip multimedia subsystem networks

Abstract: A system and method for enabling a UE to roam to a visited IMS-based network from a home network that does not have an IMS infrastructure. A visiting UE sends to an Intelligent Roaming Application Server (I-RAS) in the visited network, a first SIP Registration message that includes a SIP URI identifying the UE as a visitor from a home network that does not have an IMS infrastructure. The I-RAS rejects the registration, but includes a temporary TeI URI in the rejection message. The UE sends a second Registration message using the temporary TeI URI, which is forwarded to a Visited S-CSCF for authentication. The S-CSCF returns authentication vectors, which the UE uses to compute ciphering parameters and establish an IPSEC connection with a Visited P-CSCF. The UE then sends a third Registration message, which is accepted, and registration in the visited network is complete. The I-RAS acts as a pseudo Visited MSCΛ/LR and performs an update location procedure with the visiting UE's home network.