Power Saving in Wireless Multimedia Streaming to Mobile Devices

Wireless networks are becoming a part of everyday life for many people. When a mobile device has wireless LAN capability, multimedia content can be streamed over a wireless network to that device. However, a major disadvantage of all mobile devices is their limited battery lifetime. Multimedia streaming puts extra pressure on the battery, causing it to discharge faster. In some cases, streaming tasks cannot be completed purely because the battery of the device becomes fully discharged, which causes significant user dissatisfaction. This chapter describes adaptive buffer power save mechanism (AB-PSM), a novel power saving wireless communication solution that enables an increase in battery lifetime during mobile multimedia streaming.

Buffer Control Techniques for QoS Provisioning in Wireless Networks

This chapter introduces the network buffer control techniques as a mean to provide QoS. This problem has been extensively studied in the context of wirelined networks; however, the proliferation of wireless networks and the introduction of multimedia applications has significantly changed the characteristics of the traffic mix that flows on the network. The objective of this chapter is to create a new methodology for automatically adapting the various buffer thresholds such that the network exhibits optimal or near optimal performance even as network conditions change. The behavior of the network (generally a discrete event system—DES) is approximated by that of a stochastic fluid model (SFM); then using infinitesimal perturbation analysis (IPA) we obtain sensitivity estimators of the performance measure(s) of interest with respect to the control parameter. These estimators are easy to compute using data observed from the DES’s sample path. Finally, the computed estimators are used in stochastic approximation algorithms to adjust the thresholds.

Cross-Layer Radio Resource Management Protocols for QoS Provisioning in Multimedia Wireless Networks

This chapter introduces the cross layer design for resource allocation over multimedia wireless networks. Conventional layered packet scheduling and call admission control schemes are presented and a number of cross-layered protocols that are recently proposed are investigated. The chapter highlights the QoS improvement and the performance gain obtained while considering the interlayer dependencies concept for various real-time and non-real-time applications. The authors hope that this chapter will assist in the understanding of the cross layering and its enhancement of the layered design for QoS provisioning in future multimedia wireless networks.

Scheduling and Access Control for Wireless Connections with Throughput Guarantees

Emerging wideband code division multiple access (WCDMA) data services will likely require resource allocation to ensure that throughput targets are met. Scheduling and access control can both be key components in this task. In this chapter, we introduce a two-layer scheduler and connection access controller that attempts to balance efficiency with fairness. We first propose a scheduler that takes advantage of variations in the wireless channel—both channel fluctuations in time for each user, and channel variations among multiple users at a particular time. By mixing a max-min policy with a policy of serving users with relatively good channels, the scheduler can achieve individual average throughput targets in a manner that encourages system efficiency. We then propose a two-layer algorithm that offers targeted throughput for interactive nomadic data streams, such as video or music streaming. The design purpose is to provide users with service differentiation, which lays the groundwork for network optimization in terms of capacity or utility, and can be easily extended to revenue maximization. Upon the request of a data stream connection, a target throughput is negotiated between the user and the network/base station. The network attempts to achieve the throughput targets over the duration of each individual connection by maximizing a system objective based on users’ satisfaction that is represented by a utility function. We assume that a users’ utility function depends not only on the throughput target but also on final achieved throughput. The algorithm integrates connection access control and resource allocation per connection request with rate scheduling on a per frame basis adaptive to slow fading. Through numerical analysis, the proposed joint scheduler and connection access controller is shown to achieve the design goals.

Transport Protocols and QoS for Wireless Multimedia

This chapter introduces the QoS issues and support in transport protocols for wireless multimedia transmission. After an overview of the transport layer functionalities in a transmission and the multimedia characteristics, conventional transport layer protocols: transmission control protocol (TCP), and user datagram protocol (UDP) are described. In this chapter, some of the proposed modifications to these protocols in order to improve multimedia transmission quality in wireless networks are also summarized. Particulary, UDP Lite, TCP friendly rate control protocol (TFRC), and real-time transport protocol (RTP)--real-time transport control protocol (RTCP) are mentioned. Finally, the chapter is concluded with some discussions on the current trends in transport protocols for wireless multimedia transmission and on some of the ongoing research issues.

PQoS Assessment Methods for Multimedia Services

The concept of PQoS, although in general it deals with the user satisfaction with a specific delivered/ requested service, is in practice significantly differentiated by the nature of each delivered service. This chapter reviews various existing PQoS assessment methods for video, VoIP, online games, and Web services that have been published in the literature. It then moves beyond the current PQoS assessment methods and presents novel techniques for predicting the PQoS of a multimedia service.

Broadband Satellite Multimedia Networks

Nowadays there is an increasing need of broadband communication anytime, anywhere for users that expect to receive multimedia services with support of quality of service. In such a scenario, the aim of this chapter is to present the possibility of the satellite option that is particular attracting to bridge the digital divide in those areas where terrestrial solutions are unfeasible or too expensive. This chapter provides first a survey of the ETSI standardization framework for satellite networks. Then, resource management schemes for both forward and return link are described. Finally a suitable case study is provided for the integration of a DVB-S/DVB-RCS satellite system interconnected with a WiFi segment for local coverage; examples and results permit to understand different resource management implications.

End-to-End Support for Multimedia QoS in the Internet

An increasing demand for multimedia data delivery coupled with reliance in best-effort networks, such as the Internet, has spurred interest on effective quality of service (QoS) management for multimedia streams. Since today’s multimedia applications are expected to run in physically heterogeneous environments composed of both wired and wireless components, we assess the efficiency of transport-layer solutions for multimedia traffic in heterogeneous networks. In order to quantify the performance on media delivery, we investigate the multimedia application requirements vs. the QoS provided by the underlying network. The chapter also provides means for the perceptual QoS assessment of voice and video streams. In the sequel, we describe some representative end-to-end congestion control schemes, identifying the mechanisms that are most suitable for multimedia traffic. Our analysis is complemented with conclusive performance studies which quantify video delivery, within the context of transport protocol support and efficiency.

Multimedia Services Provision in MANETs

This chapter introduces the principal characteristics of MANETs and shows how these particularities may affect both QoS conditions and QoS management/provisioning systems, and therefore the capabilities of MANETs for properly providing multimedia services. After a deep analysis of different QoS mechanisms at different layers, the authors claim that QoS management cannot be handled only at the network layer or by applying some QoS-aware routing protocols. In fact, any end-to-end QoS provision architecture will demand QoS control mechanisms and information exchange among all the layers. A clear understanding of different proposals aimed at coping with QoS requirements at different layers will not only provide researchers with valuable information for designing better multimedia capable MANETs, but will also assist them in evaluating the need for a unified cross-layer approach in order to optimize the performance of analyzed protocols.

Radio Resource Management Strategies for HSDPA-Enhanced UMTS Networks

This chapter gives an overview of the background and functionality of the high speed downlink packet access (HSDPA), and provides insights into the radio resource management of integrated UMTS/HSDPA networks. The high speed downlink packet access (HSDPA) is part of the evolution of the universal mobile telecommunication system (UMTS). It is often referred to as 3.5G system, in contrast to UMTS, which is a third generation system. The authors introduce aspects of radio resource management specific to the HSDPA like channel-aware scheduling and radio resource sharing strategies. Furthermore, the impact of radio resource management on the quality of service is analyzed and it is shown that the selection of an RRM strategy is an integral part of the network planning and deployment process