Power and Quality of Service Trade-offs in Wireless Networks
Friday, August 10, 2001 - 10:00am - 11:00am
In wireless networks, physical layer quantities, such as the transmission rate and power, can be dynamically controlled in response to changing channel conditions and user demands. Such techniques can impact not only physical layer performance but also various network level quality of service metrics. We will discuss some models which take into account both physical layer concerns as well as some higher layer service metrics. Initially we consider a single user communicating over a wireless channel; the emphasis here is on understanding how to allocate physical layer resources in response to channel fading. Assume arriving data for the user is buffered until it is transmitted and the user's quality of service is related to the buffer delay. In this setting we study the trade-off between the user's average transmission power and the resulting quality of service. Our focus is on understanding these trade-offs in various asymptotic regimes. We also discuss some multi-user situations, where the allocation of resources between users becomes important.