Zone based hybrid approach for clustering and data collection in wireless sensor networks

A wireless sensor network (WSN) is a collection of spatially distributed autonomous sensor nodes that can be used to monitor, among other things, environmental conditions. WSN sensor nodes are constrained by their limited energy supply, communication range and local computational capabilities. Data routing is an area that can be optimized to allow nodes to conserve energy, improving the network's overall lifetime. Though many routing protocols can be used, using a clustering protocol can play an important role in conserving WSN energy. Under this approach, the network is divided into multiple clusters. The leader of each cluster supervises data transmission to the base station (BS), after removing redundant data. In this paper, a new hybrid algorithm is proposed which incorporates both distributed and centralized algorithms for selection of the cluster head (CH). Under this algorithm, the CHs for first two rounds are selected by the BS, using a centralized algorithm. For the third round onwards, the CHs are selected by the previous cluster heads using a distributed algorithm. In most networks, sensor nodes have limited energy, so a mobile data collector (MDC) is used to collect information, reducing energy requirements. The MDC acts as an interface between the CHs and the BS. The transmission of data from the sensor nodes to the CH uses a proactive algorithm and the transmission from the mobile nodes to the BS uses a reactive algorithm. The BS divides the network into outer and inner zones. The outer zone is further divided into sectors. Each member node (MN) is assigned to a sector. The MN which has the most excess energy resources is used for transmission, to conserve energy and prolong the network life time.