Topic
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.
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28 Jul 2008
TL;DR: This cutting-edge book presents state-of-the-art solutions from leading researchers active in the field to address the QoS issues for different wireless multimedia applications.
Abstract: The recent rapid advances in wireless technologies have created a demand for high quality multimedia applications and services. These advanced multimedia applications give rise to a new set of challenges in providing Quality of Service (QoS) when delivering these services over wireless networks. The Handbook of Research on Wireless Multimedia: Quality of Service and Solutions highlights and discusses the underlying QoS issues that arise in the delivery of real-time multimedia services over wireless networks. This cutting-edge book presents state-of-the-art solutions from leading researchers active in the field to address the QoS issues for different wireless multimedia applications.
13 citations
01 Jan 2007
TL;DR: In this article, the authors propose an approach to IMS policy control based on session policies that achieve transparent end-to-end session establishment between IMS terminals, which can be applied transparently to SIP dialogs between terminals and modified on the fly without tearing down ongoing dialogs.
Abstract: This article proposes an approach to IMS policy control based on session policies that achieve transparent end-to-end session establishments between IMS terminals. The article identifies drawbacks in the current IMS policy control methodology, discusses how these drawbacks may negatively influence the potential of IMS to provide innovative services, and describes how the new approach overcomes these drawbacks. Our proposal offers modularity and scalability properties that enable operators to establish policies and modify existing ones without major changes in the IMS core. Thus, policies can be applied transparently to SIP dialogs between terminals and modified on the fly without tearing down ongoing dialogs. The article also discusses a test bed implementation that worked as a proof-of-concept.
13 citations
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29 Jun 2016
TL;DR: In this article, the authors proposed a voice calling method, which comprises the following steps of determining whether a signal radio voice call continuity (SRVCC) call forwarding instruction is received or not after a calling request of an IP multimedia subsystem IMS is initiated, falling back to a 3G network or a 2G network while determining that the SRVCC call forwarding instructions is received.
Abstract: The invention provides a voice calling method, a voice calling device and a terminal, wherein the voice calling method comprises the following steps of: determining whether a signal radio voice call continuity (SRVCC) call forwarding instruction is received or not after a voice calling request of an IP multimedia subsystem IMS is initiated; falling back to a 3G network or a 2G network while determining that the SRVCC call forwarding instruction is received; judging whether configuration information of a current cell supports a circuit switch (CS) domain service or not according to the SRVCC call forwarding instruction; and if so, directly executing a CS voice call, otherwise, initiating a location registration process LAU in the current cell. By means of the technical scheme of the invention, the problem that the CS voice call is failed in the event that a 4G network only supports a PS service after being subjected to SRVCC call forwarding and falling back to a 3G or 2G network can be avoided; the calling success rate is increased; and the user experience in the voice calling process is improved.
13 citations
01 Jan 2002
TL;DR: This thesis considers design options and solutions for this model, and evaluates performance through live conferences with real conferees, finding the speaker selection of the new conference model to be transparent, and strongly preferred the resulting speech quality to that of a centralized IP-based conference bridge.
Abstract: Traditional telephone conferencing has been accomplished by way of a centralized conference bridge. An Internet Protocol (IP)-based conference bridge is subject to speech distortions and substantial computational demands due to the tandem arrangement of high compression speech codecs. Decentralized architectures avoid the speech distortions and delay, but lack strong control and have a key dependence on silence suppression for endpoint scalability. One solution is to use centralized speaker selection and forwarding, and decentralized decoding and mixing. This approach eliminates the problem of tandem encodings and maintains tight control, thereby improving the speech quality and scalability of the conference. This thesis considers design options and solutions for this model, and evaluates performance through live conferences with real conferees. Conferees found the speaker selection of the new conference model to be transparent, and strongly preferred the resulting speech quality to that of a centralized IP-based conference bridge.
13 citations
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03 Nov 2010Abstract: Methods and apparatus for inter-device session transfer between devices operating according to different protocols are disclosed. The session may be a multimedia session supported by. Session Initiation Protocol (SIP) and the H.323 standard. The devices may include a SIP Client or an H.323 Client. The SIP Client may be an IMS-based SIP Client. An InterWorking Function (IWF) may support a session transfer from a SIP Client to an H.323 Client or from an H.323 Client to a SIP Client. A Media Gateway Control Function (MGCF) may support a session transfer from an Internet Protocol (IP) Multimedia Subsystem (IMS)-based SIP Client to an H.323 Client or from an H.323 Client to an IMS-based SIP Client.
13 citations