Improvement of non-uniform node deployment mechanism for corona-based wireless sensor networks

The promising technology of Wireless Sensor Networks (WSNs), lots of applications have been developed for monitoring and tracking in military, commercial, and educational environments. Imbalance energy of sensors causes significant reduction in the lifetime of the network. In corona-based Wireless Sensor Networks (WSNs), nodes that are positioned in coronas near the sink drain their energy faster than others as they are burdened with relaying traffic come from distant coronas forming energy holes in the network. This situation shows significant effects on the network efficiency in terms of lifetime and energy consumption. The network may stop operation prematurely even though there is much energy left unused at the distant nodes. In this thesis, non-uniform node deployments and energy provisioning strategies are proposed to mitigate energy holes problem. These strategies concerns the optimal number of sensors required in each corona in order to balance the energy consumption and to meet the coverage and connectivity requirements in the network. In order to achieve this aim, the number of sensors should be optimized to create sub-balanced coronas in the sense of energy consumption. The energy provisioning technique is proposed for harmonizing the energy consumption among coronas by computing the extra needed energy in every corona. In the proposed mechanism, the energy required in each corona for balanced energy consumption is computed by determining the initial energy in each node with respect to its corona, and according to the corona load while satisfying the network coverage and connectivity requirements. The theoretical design and modeling of the proposed sensors placement strategy promise a considerable improvement in the lifetime of corona-based networks. The proposed technique could improve the network lifetime noticeably via fair balancing of energy consumption ratio among coronas about 9.4 times more than other work. This is confirmed by the evaluation results that have been showed that the proposed solution offers efficient energy distribution that can enhance the lifetime about 40% compared to previous research works

Low complexity energy-hole detouring scheme with energy harvesting

Energy problem is an important consideration in wireless sensor network. It is because sensor nodes in network use limited battery source which leads to limited lifetime. Also, sensor nodes in WSNs use multi-hop communication, so nodes near sink node transmit more data compared with farther nodes. These phenomenon results in energy hole problem which is critical to prolong lifetime of sensor network. So We proposed energy efficient and low complexity detouring scheme to prevent energy hole problem in advance. For better environment of WSN, energy harvesting technology is used in this work. Although the amount of energy charged by energy harvest sources is not always enough to meet the requirement of WSNs, proposed scheme can be good at lifetime of network. With this method, beginning time of energy hole can be postponed and it will network lifetime more extended