| The research-results comprised in this thesis address the lifetime problem in large-scale wireless sensor networks. The proposed methodologies target the efficient handling of the information load from a two-fold perspective: (1) by providing load-balancing, and (2) by reducing the information load altogether, as two correlated dimensions of the lifetime problem: the energy balancing dimension, and the energy efficiency dimension respectively. We propose several methodologies to address each dimension of the problem. First, we propose and analyze the lifetime performance enhancement provided by the Multi-Pole Field Persistent Routing (MP-FPR) protocol, which contains an alternate path routing methodology that provides rich path diversities and quality of service (QoS) semantics. A thorough security evaluation of MP-FPR protocol is performed and adequate authentication, integrity and other specific security defense mechanisms are identified and analyzed. Subsequently, we address the energy efficiency in tracking application domains, by proposing distributed variants of poly-line simplification algorithms for the purpose of reducing the trajectory representation of a moving target. In the same context, multiple buffer management policies are studied. Lastly, a new methodology that incorporates tracking epoch semantics into the tracking process is presented, namely the Sampling Look-Ahead Selection (SLS) methodology, for reducing the number of tracking principals required to adequately cover the trajectory of a moving target. |
