| The recent advancements in micro electronic systems and smart sensing material have enabled the manufacturing of miniature and smart wireless sensors. Sensors are used for detecting physical phenomena such as temperature, pressure, sound, light, electromagnetic field, vibration, gas leaks, etc...In practice, the surveillance of critical areas requires the placement of sensors such that several criteria are satisfied, for example, coverage, connectivity, energy dissipation, cost...etc. This thesis deals with finding the optimal placement of wireless sensors and signal relays in 2-D or 3-D space. The relays receive signals from the sensors and re-transmit them to other relays all the way to a central processing node. A bi-objective integer linear program (ILP) is designed to find the locations of the sensors and the relays while minimizing the total network cost and the total network power consumption simultaneously. The ILP locates the sensors such that all critical points are covered by their minimum criticality. The relays are placed so that the network connectivity is guaranteed. A space partitioning heuristic method is designed to overcome the expensive computational time of the ILP and provide nearoptimal solutions. Solved examples are presented to show the output and performance of both the ILP and the heuristic method.;Keywords: optimization, integer linear program, sensors, relays, wireless sensors network, space partitioning heuristic. |
