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.

XML-Driven Framework for Policy-Based QoS Management of IMS Networks

Abstract: Policy Based Network Management (PBNM) simplifies the administration and management of communication networks. However due to the wide variety of policy representation forms, interoperability between different entities of PBNM systems becomes a concern. The Common Open Policy Service (COPS), which was standardized for policy control between a Policy Decision Function (PDF) and Policy Enforcement Point (PEP) had considerable shortfalls in efficiency and flexibility - its successor the Diameter protocol exhibits interoperability shortfalls. An XML-based policy provisioning solution presents great modeling capabilities that may overcome these shortfalls. The IP multimedia subsystem has adopted PBMN as the mechanism for resource and admission control. This paper reviews an XML- driven architecture for policy control of DiffServ networks, and explores the incorporation of the proposed architecture into the IMS framework to perform policy control and enforcement. Proof of concept results of the XML-based policy control architecture are presented alongside design requirements for using it as an alternative to diameter for IMS policy control.

Presence service in IMS.

Abstract: This paper describes the presence service, which is located in the IP multimedia subsystem. This service allows making many applications for different groups of people. The paper describes differences between a network without the service and with the service. The biggest change is an increased number of transmitted messages. The presence uses some part of the IP multimedia subsystem control layer, which is shown in communication between the user and the server. The paper deals with the number of generated messages depending on the behaviour of the users. This is described by a mathematical model using discrete Markov chains.

Unified ims supplementary services signaling across circuit and packet domains

Abstract: The present invention provides a method for signaling between an IP Multimedia Subsystem (IMS) and a multi-mode terminal using concise primitives to support the use of IMS-based services while the multi-mode terminal is attached to either the packet switched (PS) domain or to the circuit switched (CS) domain, or moves between these domains. The present invention enables the maintenance of services state in only the IMS and in the multi-mode terminal, thus avoiding the creation or transfer of services state information as the multi-mode terminal moves between the PS and CS domains.

Dispatch Network with IMS Integration

Abstract: A wireless communications system includes a radio network facilitating wireless communications with a wireless subscriber unit, a dispatch application server providing dispatch communications services to the subscriber unit via the radio network, and an IP Multimedia Subsystem (IMS) infrastructure including a Proxy-Call Session Control Function (P-CSCF) and a Serving-CSCF (S-CSCF) The P-CSCF notifies the dispatch application server of subscriber unit registration events, allowing the dispatch application server to provide dispatch communications services without initiating a separate registration process Dispatch communications are routed between the wireless subscriber unit and dispatch application server through the P-CSCF, bypassing the S-CSCF of the IMS infrastructure

Terminal-Centric Location Services for the IP Multimedia Subsystem

Abstract: Location-based services in 3G and beyond networks depend on high-accuracy location data. Today's 2G and 3G access networks determine user location in a network-centric manner. The accuracy of these location mechanisms depends on the radio infrastructure near the user's geographical position and is typically limited to hundreds or thousands of meters. This precision is inadequate for typical location-based services like city maps or route planners. In this paper we present a terminal-centric location enabler that integrates seamless with the existing IP Multimedia Subsystem presence architecture and interoperates with network-centric location mechanisms. We argue that the user terminal itself, equipped with location sources like GPS receivers, can determine the geographical position with an optimum of accuracy. In consequence, the user terminal should be used as the primary source for location information. We extend the existing and well-known concept of presence by defining location as a type of presence information that is of interest to users. Terminal-based triggers and filters reduce the amount of traffic on the air interface and enable a scalable location architecture. We present the implementation of a J2ME-based mobile terminal prototype, which uses GPS as location source and interfaces with IMS location services.