Base Station Positioning in Single-Tiered Wireless Sensor Networks

In wireless sensor networks, sensor nodes collect data from the surrounding environment and transfer it to the base station. If a sensor node cannot communicate with the base station directly, it needs to select one of the senor nodes that it can communicate with and transfer the data to it. The above process will go on until the data arrive at the base station. It may cause too many relays during the process in which the data are transferred to the base station. Some nodes may quickly run out of energy and cause the entire wireless network to fail. We build a breadth-first search spanning tree which is rooted in base station according to the connected relation between the sensor nodes and the base station. When sensor nodes transfer the data to the base station, the data follow the path between the node and root in the spanning tree towards the base station. This algorithm guarantees the number of relays in the process and the total energy consumption of the wireless sensor network are the least. Thus the choice of the base station position is vital to the energy consumption of the whole wireless sensor network. This paper proposes an algorithm for the base station placement that finds the optimal base station position by using computation geometry according to the relative relation between the senor nodes. In contrast to the grid computing we are familiar, this algorithm greatly reduces the computing time required by finding the optimal position of base station.