Issues in Wireless Access Broadband Networks

In this paper, we discuss the effect of wireless link characteristics and mobility in wireless access broadband networks, and how major differences between wireline and wireless transmission links introduce a new networking paradigm with difficult and interesting challenges. We show that these differences have a direct impact on the packet-level quality-of-service defined by the packet loss, delay and jitter statistics. Moreover, we examine a number of alternatives such as forward error correction, antenna diversity and retransmission schemes to combat the time varying nature and high bit error rate of the wireless link, as well as how much and in what way these schemes can improve the packet-level quality-of-service. We also show that routing, call admission control, and capacity allocation functions of wireless access broadband networks need to take mobility into account. These functions can be invoked in a re-active manner at every hand-off event, or they can be invoked in a pro-active manner at the call setup time instead of being invoked at every hand-off event. In addition, we discuss the trade-offs between these two call control schemes, and show that each of these schemes is associated with a major cost. To find a balance between the cost of these two call control schemes, we use a connection tree as a basis for routing, call admission control, and capacity allocation in wireless access broadband networks. Finally, we discuss a number of issues in traffic integration for wireless access broadband networks and how they differ from wireline broadband networks.