Preface

The introduction of wireless communication is dramatically changing our lives. The ability to communicate anytime, anywhere increases our quality of lives and improves our business productivity. The recent technological developments that allow us to execute bandwidth-hungry multimedia applications over the wireless media add new dimensions to our ability to communicate. This opens an array of exciting opportunities in business, residential, healthcare, education, leisure, and many other areas. Wireless videoconferencing will connect us with business partners and family members. Remote video medical consultation will enhance care in rural areas and at the accident scene. Interactive games that include video and graphics with partners over the globe will add new dimensions not only to our leisure opportunities but also to provisioning of an effective remote learning environment.

Such opportunities are possible due to the recent technology developments in 1) user device miniaturization, which enables adequate computation power and display in small mobile handheld devices, and 2) provisioning of significantly broader wireless links for carrying multimedia traffic. Such broader links have been introduced in the wide-ranging wireless networks including very short-range personal wireless networks, short-range local area networks, and longer range metropolitan, cellular, and satellite networks. Because of nature of the wireless environment, these links are shared among many users executing multiple applications, each requiring different levels of quality of service (QoS) support. Therefore, each wireless network needs to incorporate bandwidth mediation policies that enable QoS support to the different multimedia applications. It is interesting to note that the wireless networks' standards do not provide the algorithms required for such bandwidth mediation policies. Such policies are the motivation for writing this book.

Wireless networks are described in numerous public domain documents produced by standard organizations in the U.S., Europe, Asia, and other continents whose members include hundreds of participants representing companies all over the world. These organizations include IEEE (Institute of Electrical and Electronics Engineers), ETSI (the European Telecommunications Standards Institute), and ITU (International Telecommunication Union). The fact that these standards are produced by such an impressive collaboration of participants and are public domain is the basis for making these standards a true, easy means for global communication. Next generations of wireless networks include Wireless Personal Area Networks (WPANs), Wireless Local Area Networks (WLANs), Wireless Metropolitan Area Networks (WMANs), and cellular and satellite networks (see Figure 1).

Figure 1. The Big Communication Puzzle

The provision of a quality experience for the end-users requires end-to-end QoS support in terms of bandwidth, delay, and delay jitter. In order to provide end-to-end QoS support, we need to provide QoS in the wide area network (the Internet) as well as in the wireless extensions (WPAN, WLAN, WMAN, and cellular and satellite networks).

This book is a comprehensive guide to understanding multimedia wireless networks. The book addresses the QoS problems and solutions, discussing the architecture, applications, and implementation of wireless networks, including a number of standards and proposed standards. In this book we introduce the basic QoS support mechanisms and the standards and standardization efforts in the aforementioned array of network technologies. We focus on describing the standards' signaling mechanisms that need to be incorporated in the bandwidth mediation policies developed by network designers. We hope that the reader will realize that the development of algorithms that provide QoS support for different multimedia applications is a very complex task. We also hope that the reader will understand the available signaling mechanisms for each one of the wireless standards. Using the knowledge base provided in this book the network developers can take the necessary steps into the development and implementation of QoS mechanisms within their target wireless networks.

This book is not intended to replace the standards' documents for any design purposes. Its sole intention is to help and simplify the introduction of such standards and to provide an easy tool for making an initial comparative analysis between the different approaches presented by the standards in supporting multimedia traffic. Since the standards contain hundreds and thousands of pages of detailed information, using our personal judgment, we had to omit significant details, which we felt are less useful. Thus, we strongly recommend that for a detailed analysis and design purposes, the reader should refer to the official standards' documents.

To the best of our knowledge, this is the first book that covers such a broad array of wireless networks with a focus on multimedia support. We certainly hope to continue and develop the presented topics further by including material that describes how network designers and operators use the tools provided by the standards for providing users with an enjoyable multimedia experience. Hence, we will appreciate your feedback and input via email to Aura Ganz (ganz@ecs.umass.edu).