Plenary lecture 1: traffic monitoring and rate allocation in sensor networks
Titsa P. Papantoni-Kazakos · 2009
Wireless sensor networks are special purpose structures: their architectures and operations are designed to satisfy pre-specified signal processing objectives. Thus, the overall performance of a wireless sensor network is determined by the satisfaction of the performance criteria that are pertinent to the undertaken signal processing objective. Signal processing objectives are classified as either detection among finite hypotheses, or parameter estimation or estimation of the acting data generating process, and the pertinent performance criteria include decision/estimation accuracy and conve4rgence rate, where detection/estimation accuracy is generally monotonically increasing with the number of observation data processed. When time constraints are imposed on high accuracy detection/estimation, the consequence is increased required overall data rates. At the same time, in wireless sensor networks, observation data are collected and processed by life-limited nodes, whose life -span is a function of the data rates they process. Thus, required overall data rates, in conjunction with rate-dependent node life-spans, necessitate networkarchitecture and network-operations adaptations, so that the nodes' survivability limitations do not interfere with the required network overall performance. Since the network-architecture and network-operations adaptations are functions of the acting data rates, it is eminent that data rates be monitored and that rate changes be detected accurately and rapidly. In this talk, we consider a wireless sensor network whose architecture consists of micro-sensors, microsensor clusters and a backbone network of cluster-heads and a fusion center. The network's purpose is to execute a signal processing operation, while honoring the time constraints and the performance requirements imposed by the application and while adhering to the limited life-spans of the sensors and the cluster-heads. Data rates are time-varying in such a network, mainly due to expiring life-limited nodes. We focus on the problem of dynamic rate allocation, facilitated by a rate monitoring higher level protocol. We present a rate monitoring algorithm and study the stability of the rate allocation/rate monitoring coupled system.