With the advancement of multimedia compression technology and wide deployment of wireless networks, there is an increasing demand especially for wireless multimedia communication services. The system design has many challenges, such as fading channels, limited radio resources of wireless networks, heterogeneity of multimedia content complexity, delay and decoding dependency constraints of multimedia, mixed-integer optimization, and trade-offs among multiuser service objectives. To overcome these challenges, dynamic resource allocation is a general strategy used to improve the overall system performance and ensure individual QoS. Specifically in this chapter, we consider two aspects of design issues: cross-layer optimization and multiuser diversity. We study how to optimally transmit multiuser multimedia streams, encoded by current and future multimedia codecs, over resource-limited wireless networks such as 3G cellular systems, WLANs, 4G cellular systems, and future WLAN/WMANs.

Introduction

Over the past few decades, wireless communications and networking have experienced an unprecedented growth. With the advancement in multimedia coding technologies, transmitting real-time encoded multimedia programs over wireless networks has become a promising service for such applications as video-on-demand and interactive video telephony. In most scenarios, multiple multimedia programs are transmitted to multiple users simultaneously by sharing resource-limited wireless networks.

The challenges for transmitting multiple compressed multimedia payloads (such as videos) over wireless networks in real time lie in several factors. First, wireless channels are impaired by detrimental effects such as fading and CCIs. Second, there are limited radio resources, such as bandwidth and power, in the wireless networks.