| Recent years have witnessed a growing interest in the applications of Wireless Sensor Networks (WSNs). Most notable among these applications are those operating in hostile environments space exploration, border protection, combat field reconnaissance, and search and rescue. Due to the harsh surroundings, WSNs may suffer from a large scale damage that causes many nodes to fail simultaneously and the network to get partitioned into multiple disjoint segments and its services become very limited. In such a case, restoring the network connectivity is very important in order to avoid negative effects on the applications. Linking disjoint segments may not be feasible through coordinated repositioning of some set of nodes as the scope of the damage is so wide that cannot be determined. One of the viable solutions for federating damaged WSNs is to deploy additional resources, i.e. relay nodes, to form inter-segment multi-hop paths.;In this dissertation, we tackle technical challenges related to the federation of segmented WSNs. We present a set of effective techniques that for repairing the damaged WSN using the least number of relay nodes (RNs) as well as maintaining some desirable topology features such as robustness against failures, network coverage and balanced traffic load. The correctness and time-complexity of all proposed approaches are analyzed and their performance is validated through extensive simulation experiments. |
