Optimum Routing in Wireless Sensor Networks with Random Node Locations

Due to the unsupervised nature of wireless sensor networks (WSNs), intensive communications are required among the selected nodes to reach a consensus and synchronize prior to entering an Optimum Routing (OR) procedure. Directivity of the proposed OR technique is analyzed and an extension of the technique to a multi-ring case is presented. It is shown that the sidelobe peaks can be considerably decreased if the nodes are selected from multiple concentric rings. Location and intersensor distance estimations are important functions for the operation of wireless sensor networks, especially when protocols can benefit from the distance information prior to network deployment. The maximum OR thatcan be covered in a given number of hops in a sensor network is one such parameter related with coverage area, delay, and minimum OR transmission energy consumption estimations. In randomly deployed sensor networks, intersensor distances are random variables. Hence, their evaluations require probabilistic methods, and distance models should involve investigation of distancedistribution functions. Current literature on analytical modeling of the maximum distance distribution is limited to 1D networks using the Gaussian pdf. However, determination of the maximum OR distribution in 2D networks is a quite complex problem. Furthermore, distance distributions in 2D networks are not accurately modeled by the Gaussian pdf. Hence, we propose a greedy method of distance maximization and evaluate the distribution of the obtained OR through analytical approximations and simulations.