| In our research, we study data forwarding in WSN. The main parameters that affect the operation of data forwarding from sensor nodes to sink are identified. Based on our study of the existing protocols, we propose a framework to forward data from sensor nodes to sink. A cross layer design methodology is adopted in designing our framework. Our framework aims at maximizing network lifetime. The proposed framework is called a Generalized Energy-Efficient Time-Based communication protocol (GET). In GET, any node can communicate with the sink directly, and an energy efficient tree is constructed from all nodes toward the sink. Based on this tree, a TDMA schedule is built to forward data from all nodes to the sink. GET is validated using different network configurations and it shows good improvements compared with EAD and LEACH. Moreover, An Energy Efficient Data Communication Protocol (EEDS) which is a special case of GET is proposed. In EEDS, only the nodes that are close to sink can communicate with it directly. In addition, we generalize the Energy-Aware Data Centric Routing (EAD) such that any node can communicate with the sink directly. The new protocol is called EADGeneral. Extensive simulation experiments show that EADGeneral outperforms EAD. Moreover, we proposed Information-Entropy based metric to measure the throughput in WSN. In the new metric, we defined the throughput as the amount of information delivered to the sink. The proposed metric yields a better understanding of the operation of the WSN application. Finally, to explore the optimal solutions that can be produced assuming global information, we formulate EEDS with an integer linear programming (ILP) model. We proposed four cost functions for the ILP model. We used LINGO solver to solve our model. The results obtained by solving the ILP model under the first cost function are compared with the results obtained by simulation. Moreover, optimal solutions using different cost functions for different network configuration are compared. |
