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.

Telephony endpoint routing in an ip multimedia subsystem

Abstract: The present invention provides a mechanism whereby a session established at a particular MGCF between a subscriber of a legacy network and a first user of a referral service can be replaced by another session to be established between the subscriber of the legacy network and a second user of the referral service without disturbing the sessions already established. Therefore, the present invention provides a new method and devices for generating an IMS Telephony Endpoint, which includes a first information field with a telephony Universal Resource Identifier identifying an originating or destination subscriber, as the case may be, and a second information field with information usable to identify the generating MGCF as the particular MGCF holding a session for such served subscriber. Such ITE is submitted towards the IMS and is included in a further referral service request involving such session so that the particular MGCF may be identified.

Method and apparatus supporting ip multimedia subsystem

Abstract: A method and apparatus for supporting multiple IMS networks includes an electronic device supporting multiple IMS networks. A modem receives communication services through an access network and multiple IMS networks including first and second IMS networks; and a communication control module includes a processor. The communication control module is configured to attach the electronic device to the access network on the basis of first identification information corresponding to the access network, register the electronic device in the first IMS network via the access network on the basis of second identification information corresponding to the first IMS network, and register the electronic device in the second IMS network via the access network on the basis of third identification information corresponding to the second IMS network.

Methods and apparatuses for p-cscf restoration based on ue capabilities

Abstract: The present invention faces the issue of UE enabled to communicate with an IP Multimedia Subsystem following protocol versions older than Release 9, and provides for an alternative P-CSCF restoration procedure. In this alternative P-CSCF restoration procedure, the UE submits to the IMS network UE capability information indicating that the UE is enabled to receive a list with one or more further available P-CSCF entities and to re-register in the IMS network with one of them; at least one entity of the IMS network stores this UE capability information; upon detecting unavailability of the P-CSCF entity to handle a terminating request towards the UE, the UE capability information is provided towards and access network entity; the access network entity determines based on the received UE capability information that the UE is enabled to receive a list with one or more further available P-CSCF entities, obtains the list with further available P-CSCF entities and submits said list to the UE; and the UE reregisters to a further P-CSCF entity selected from the list.

System and method for non-ims application service access over ip multimedia subsystem

Abstract: A system and method to enable mobile devices to access non-IMS application services over an IP Multimedia Subsystem (IMS) is described herein. In order to access a non-IMS application service via the IMS, messages in a format that are suitable for exchange with the non-IMS application service are encapsulated by the mobile device user agent into SIP messages. The SIP messages are then routed by the IMS to a services gateway. The services gateway extracts the application service messages from the SIP messages and provides the extracted messages to the appropriate application service. In this fashion, the mobile device is able to request services from an application service via SIP messaging, even if the requested application service does not support SIP messaging.

Enhancing End-to-End QoS for Multimedia Streaming in IMS-Based Networks

Abstract: Convergence of the emerging IP Multimedia Subsystem(IMS) includes unlicensed, nondedicated and nondeterministic hence uncontrollable. computer access, networks for IP multimedia services. It enables provision of resource demanding real-time services and multimedia communication raising new end-to-end Quality-of-Service (QoS) challenges, for which quality adaptation using resource management is proposed as a solution in this paper. This is an integrated solution taking both IMS and computer access networks into account as well as the two end-devices and the application servers (AS) involved in communication. The best user experience is targeted under real-time variation of available network (e.g. bandwidth, buffer space) and end-device (e.g. battery, CPU, memory, storage) resources throughout a session. The multimedia content is dynamically adapted to fit the resource availability variations, achieving maximum system (i.e. network and end-devices) resource utilization and enhanced QoS. The resource availability update signalling is carried over Session Initiation Protocol (SIP) during the session. This is work in progress.