Real-time resource availability signaling in IP multimedia subsystem networks

IP Multimedia Subsystem (IMS) allows the use of unlicensed, non-dedicated and nondeterministic access networks for delivering IP multimedia services. Providing end-to-end Quality-of-Service (QoS) for resource demanding real-time services (e.g. real-time multimedia) over such networks is a challenging task due to varying resource availability of the network and the end-devicei during a single sessionii. A common solution to this problem is adapting service quality and type according to availability of system resources, which requires end-to-end monitoring and signaling of resource availability during a single session. This paper presents an extension of the IMS architecture for real-time resource availability monitoring and signaling. The novelty of the proposed extension is twofold. It takes into account uncontrolled access networks with no resource reservation on the one hand, and end devices on the other. Two system architecture components are introduced for monitoring and signaling of the real-time resource availability in both networks (e.g. bandwidth, buffer space), and end-devices (e.g. battery, CPU, memory, storage), namely a Resource Manager (RM) and a Resource Availability Server (RAS). Our solution does not require any modifications of the IMS architecture and can be implemented as a plug-in

Multimedia streaming adaptation IMS-networks

Introduction Multimedia services such as video, gaming and music marked the close of the last century and have become inextricably linked with our lives in the current century. The success and popularity of these services was fuelled by the explosive expansion of the Internet and the furious penetration of broadband networks. In particular, the use of multimedia streaming services on portable devices has been popular whenever both the content and the perceived delivery quality have met the expectations of end users. This chapter of the book does not address content aspects of multimedia streaming services. Such matters are left to media gurus and other researchers. Rather, this chapter focuses on the delivery quality of multimedia streaming services. Particular attention is paid to quality adaptation techniques intended to improve end users' experience of such services. Our scope includes heterogeneous networks and devices. The solutions presented are applicable to the telecommunications industry

Real-time resource availability signaling in IP multimedia subsystem networks

ABSTRACT IP Multimedia Subsystem (IMS

Per-GOP Bitrate Adaptation for H.264 Compressed Video Sequences

In video transmission over packet data networks, it may be desirable to adapt the coding rate according to bandwidth availability. Classical approaches to rate adaptation are bitstream switching, requiring the storage of several pre-coded versions of a video, or layered (scalable) video coding, which has coding efficiency and/or complexity penalties. In this paper we propose a new GOP-level rate adaptation scheme for a single stream, variable target bitrate H.264 encoder; this allows each group of pictures (GOP) to be encoded at a specified bitrate. We first compare the performance of the standard H.264 rate control algorithm with the proposed one in the case of constant target bitrate. Then, we present results on how close the new technique can track a specified per-GOP target bitrate schedule. Results show that the proposed approach can obtain the desired target rates with less than 5% error