Research On Aggregation Tree Routing Protocol For Wireless Sensor Networks

Wireless sensor networks (WSNs) are composed of many sensor nodes. The nodes have such abilities as information collection, data storage and forwarding, calculation and data processing, and wireless communication capability, and they organize themselves into a distributed network system in a multi-hop self-organizing way. The application of WSNs involved in the field is very common, e.g., military defense, environmental monitoring, biological and medical treatment, emergency rescue, disaster relief, commercial application, etc. As a result, many researchers have been attracted to research deeply in this field. Because of the limited energy and the finite storage capability of nodes in WSNs, the issues on how to maximize the network energy balance and guarantee the data transmission reliability, as well as to research on routing with the premise of high efficiency transmission have become hotspots in WSNs. However, the routing protocol design, considering multiple constraints such as network life cycle, delay, reliability, energy balance, etc., has been proved to be a NP-Hard problem. Therefore, how to maximize approximate optimal values has important theoretical and practical significance of research on WSNs.The routing protocol is mainly responsible for routing discovery and maintenance, to ensure that packets can be transmitted timely and effectively from the collection nodes to the sink ones in one hop or multi hops. Obviously, routing protocol design will directly affect the quality of the network life cycle, reliability, delay, packet loss rate etc. So it is very important to design an efficient routing protocol for WSNs.This paper consists of the following:(1) The prevailing research of the routing protocol on WSNs are reviewed, and introduced the system structure, protocol stack, key issues of WSNs. Then introduced the basic concept, characteristics, the design requirements and classification of routing protocol in the detail. And presented seven kinds of typical routing protocols, analyzing and comparing from considering whether it has energy conservation, data merge, extendibility, robustness, supports Quality of Service, etc.(2) Described briefly the collection tree protocol, and analyzed the current scholars improved protocol which has the disadvantages. Then this paper proposed an improved I-CTP protocol, in which data communication path is indicated by the expected values of transmission and considering the residual energy of next hop neighbor nodes in the transmission process in order to realize the energy consumption of the dynamic network. The simulation results show that, the improved I-CTP protocol can reduce the transmission delay, improve the network energy balance, and prolong the network life cycle.(3) In order to ensure reliability in packets transmission, introduced the reliability factors. Under the premise of reliability, further analyzed the structures of data frame packets and routing frame packets and then introduced transmission delay, ATT. Conclusively, put forward the QRE-CTP routing protocol, as it ensured reliability premise, satisfying the minimum transmission delay, and considering the remaining energy of nodes at the same time. The protocol selected the next hop path by considering three factors such as the quality of links, transmission delay, and the node residual energy synthetically, resulting in reducing the packet loss rate effectively and improving network life cycle.