A Data-based Cross-layer Forwarding Protocol For Wireless Sensor Networks

Sensor nodes are the basic unit of wireless sensor networks, due to the small size and energy resources, computing power and communication capabilities are very limited, thus reducing power consumption is an important issue in the design of wireless sensor network protocol.This thesis firstly analyzes the topology control algorithms, routing protocols, MAC protocols, and cross-layer protocols designed to study the status quo of wireless sensor network. Using cross-layer design idea, integrating the routing protocols and MAC protocols together to achieve information exchange each other, a data-based cross-layer forwarding protocol is proposed in WSN. In this protocol, the transmission of data is not established in the strict sense of end-to-end routing, but according to the current state of the network, solving synchronously the path generation and the using of channel. In other words, according to the locating, residual energy of nodes to determine the degree of forwarding priority, the sending node choose a node as the forwarding node which forwarding priority is max, and dynamically generate the next hop forwarding path, in order to adapted to data-centric and dynamic topology characteristics of WSN.For event-driven sensor network, nodes do not have to remain in the active situation in the absence of detected events. The introduction of wake up and sleep mechanism of nodes in sensor networks, so that the node's wireless communication module is turned off in the most of the time, thus significantly reducing node power consumption, to achieve energy-saving purposes. On the other hand, according to the node residual energy adaptive to change its position in the network, let nodes of maximize the residual energy to undertake the forwarding, thus the energy of nodes can effectively be balanced in the network, and the network lifetime can effectively be extended, too.The simulation results show that the protocol is well in a balanced network of energy and prolong the effective life cycle.