Chapter 13 QoS Support in Multimedia Wireless Environments

Over the couple of years, there has been a strong proliferation in the use of multimedia wireless technology all over the world, creating new research and business opportunities for producers and consumers of these technologies. There are several reasons for this fast proliferation. First, wireless networking technologies such as cellular networks, wireless local area networking (WLAN) and Bluetooth are becoming an integral part of our communication environment. Second, new wireless devices such as cellular phones, PDAs, laptops are emerging to assist people in their lives. Third, multimedia applications became known, first in Internet environment, and now are embedded in wireless environments, due to (a) standardization of digital multimedia content such as MPEG-2, MPEG-4, H.263 and others, and (b) understanding of multimedia applications/and users behaviors under different networking conditions. This allows service providers to build larger scale known (from analog world) multimedia services such as video conferencing, video-on-demand, and offer them to larger population. Fourth, new hardware opportunities are appearing such as multi-frequency energy-efficient processors allowing for more efficient use of mobile devices. However, these new opportunities bring with them also various challenges. We will concentrate on addressing two major challenges. First, mobile devices running distributed multimedia applications and communicating over wireless networks must deal with scarce and variable resource allocations such as battery