Research On Routing Protocol For Virtual Backbone In Wireless Sensor Networks

The technology of Wireless sensor networks integrates the technology of data gathering, data proceeding and data communication. It is widely used in environment and military monitoring, earthquake and weather forecast, and exploration for underground and outer space. Because of the uncertainty the outer environment, we need to dispose thousands of sensor nodes which can collaborate with others to complete the task in the region. So the research of large scale of wireless sensor networks becomes more and more popular. And the technology of wireless sensor networks has been regarded as the most important technology in the future.Usually, the sensor nodes are sprinkled in the air on the monitoring region. They compose the network by self-organized pattern. The sensor nodes transmit the sensor data to Sink nodes by multi-hop relay manner. And finally, the Sink nodes transmit the data to the data center by internet. The wireless sensor network is different form former networks. Firstly, the density of the sensor nodes in the network is as high as 100 nodes per square meter, so it is impossible to allocate the global ID for every node. Secondly, the power level, memory capacity and the capability of computing of the sensor nodes are limited. As the ad hoc networks, wireless sensor networks have not backbone and the topology of the networks changes much more. So the traditional routing protocols are not suitable for wireless sensor networks. We must research new routing protocols for wireless sensor networks.We must construct the backbone before using routing protocols transmit data. But as we known, the number of sensor nodes in wireless sensor network is very large. So how to form an appropriate backbone becomes an important problem. Backbone routing protocols can be classified as proactive protocols and reactive protocols. The proactive protocols perform better than reactive protocols in large number and data transmitting continuously networks. Proactive protocols can also be classified as layer selection, spinning-tree selection and CDS selection. LEACH is a typical proactive layer selection protocol. Based on LEACH protocol, this paper proposes an advanced backbone protocol named PRBN.This paper analyzes the LEACH protocol and proposes a new idea that building multi-hop backbone to transmit the data periodically. The procedure of building a backbone can be followed by two phase. It calls the first phase backbone-node selection phase. There is a new backbone-node selection strategy introducing two rules which make the distribution of the key-node more appropriately. The backbone-expand phase is the second phase. The backbone will be supplement and becomes an connectively multi-hop backbone. And the procedure of building the route is just the procedure of the selection of the father nodes. Every nodes can connects a backbone-node and transmit the data. This paper simulates the new protocol using NS2. The results certify that the new protocol enlarge the scale of the wireless sensor networks, that the connectivity of the network and the distribution of the key-nodes are improved, that the consumption is also very low which prolong the life time of the network. So the new protocol is appropriate for wireless sensor networks which transmit the data continuously.