Network-Aware Distributed Algorithms: Challenges and Opportunities in Wireless Networks

Abstract

Wireless networks differ from typical wired networks in several significant ways.Wireless channel is a broadcast medium, resulting in interference between simultaneous transmissions on the wireless channel. Wireless channel conditions vary over time and space, making it necessary to adapt to the time-varying conditions. The wireless signals can propagate along different paths from a transmitter to a receiver, resulting in channel fading.

These characteristics of the wireless medium can degrade performance. However, the same characteristics also offer potential performance benefits. For instance, the broadcast nature of the wireless medium may allow the nodes to overhear transmissions intended for other hosts. Fading may degrade instantaneous performance of a given user when the channel is in fade, however,multi-user diversity schemes can exploit fading to improve performance. Many wireless communications mechanisms have been designed over the years to realize such performance benefits.

Not surprisingly, being aware of the underlying network characteristics can help improve performance of distributed algorithms as well. This talk introduces some simple examples of distributed algorithms that can benefit by paying attention to the wireless network characteristics, and describes some topics for future research.