Reseach Of A Hybrid Energy Balanced Loop-free Routing Protocol For Wireless Sensor Networks

As a new technology which will change the human interactions with the physical world, WSNs(Wireless sensor networks) have been developed for a wide range of civil and military applications, such as environmental monitoring, traffic control, battle field surveillance, public security, smart home and so on. The development of IOT(Internet of Thing) pushes WSNs forward froming a big-scale, commercialized, organized one.Wireless sensor nodes are usually powered by limited batteries, so constrained energy is a prominent feature in WSNs. How to effectively optimize the energy consumption of sensor nodes to extend the network lifespan is one key step to make WSNs into practical applications. Routing algorithm plays an important role in improving network efficiency, extending the network lifespan, and it’s also an important research topic point in our paper. The primary studies are listed as followed:1. Analyzing the development situation, research focus, aspects of our work need to be improved and the difficult issue still unresolved in WSNs. Determine the practical significance of our research, and make a bald predictions about the application effect of this scheme proposed by us.2. Some typical energy-efficient protocols such as Mini-Hops、EBRP、MAP、AEAP, have shown good energy efficiency and data transmission efficiency. Despite their good performance, they have defects in energy-balanced. These schemes typically use the lowest energy consumption path for data transmission. But the usage of the same routes for data transmission repeatedly causes the nodes on the path to run out of their energy, and induces an unbalanced energy distribution among sensor nodes, which eventually results in network partitioning and significantly narrows the network lifespan. Hence, balancing energy consumption among sensor nodes is critical to WSNs routing protocols design.3. Based on the thorough study of typical energy-balanced protocols such as EBRP、MAP、AEAP, we propose a new energy-balanced routing protocol called HEBR(A Hybrid Energy Balanced Loop-Free Routing Protocol for Wireless Sensor Networks) by constructing a mixed 3-dimension field in terms of depth, energy density and residual energy. In HEBR, we ensure data packets always move forward by restricting the next-hop candidate set to parent nodes and sibling nodes and use different coefficients to weight residual energy and energy density to forward packets through dense energy area and protect the nodes with low energy, including routing loops detection and elimination mechanism and redundant hops removement method which can further strengthen our protocol.4. Comparisons and analysis experiments are made by Matlab for HEBR with other protocols. Simulation results show that HEBR protocol attains better energy balance among nodes with limited transmission delay and longer lifespan. Compared with Mini-hops, HEBR algorithm stretches the network lifespan by 68.72%, solving the problem called energy hole. And in terms of data transmission delay, the average hops needed to forward a data packet to the sink of HEBR is 6.5, while EBRP needs more hops about 9.1 to transmit a packet, so the HEBR protocol avoids a waste of energy and the increase of transmission delay. Therefore, we conclude that HEBR protocol is a more effective energy-balanced routing protocol for WSNs.