In -Network Computation in Wireless Sensor Networks

100 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006.Next, we study another important metric in sensor networks, which is network lifetime. We consider a formulation of maximizing network lifetime given the simple task of downloading different quantities of data over nodes with different energy levels. We reduce the problem of choosing lifetime optimal routes to a linear program, and derive closed form solutions for some simple regular network topologies. In the final part of the thesis, we consider the problem of clock synchronization over multihop networks, which is a specific instance of a network task requiring distributed computation. We analyze a clock synchronization approach which leads to a distributed vector estimation problem based on noisy estimates of clock differences of pairs of nodes which can directly exchange packets. We establish connections between the error variance of optimal least-squares clock synchronization and resistances in electrical networks. We propose and analyze the convergence time of a distributed iterative algorithm to compute the optimal estimates. We also propose ways of exploiting the network connectivity graph structure in order to speed up computation.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD