Cross Layer Design For Wireless Sensor Networks

Wireless sensor networks (WSN), is a novel technology which integrates the technologies of sensor, embedded computing, distributed information transaction and wireless communication. It is made up of lots of sensor nodes of which the character is self-organizing, mini-size, low cost and flexibility .Different kinds of nodes utilized in this network can cooperate to monitor sense and gather information of area they monitored. The data they gathered will be forwarded though multi-hop to the terminals and to be deeply dealt with. Wireless sensor networks implement the effective connectivity of the physical world, the computer world and human society, the characteristics of self-organizing; mini-size, low cost and flexibility give it a very broad perspective in many fields such as military, environment science, medical treatment, space exploration and business etc.In this paper, through analysis of the wireless sensor network protocol stack, an improved program is given, including the following two aspects:(1)A MAC protocol called ATMAC in which the duty cycle of nodes can be adjusted in accordance with traffic. In wireless sensor networks, based on famous TMAC protocol, low power energy consumption, low latency for target, ATMAC mainly adopts three options. First, adaptive and multi-level duty cycle is considered. The second is adaptive contention window. The third, Priority queue. All of these options can be utilized to save energy, minimize latency, increase output etc. Nodes can sleep more when traffic is low, while others referred in high flow can be involved in a relatively long time to be active to send or receive data, meanwhile, the duty cycle nodes adopted may vary in size. Simulation results show that new protocol exceed TMAC at the energy consumption, data delay and so on.(2) Traditional wireless network protocol can not apply to sensor networks directly. So many researchers proposed new protocol stack for wireless sensor networks. The design most scholars proposed is similar to TCP/IP protocol stack Hierarchy. There is a more strict separation of tasks between layers, making such a structure used in wireless sensor networks have some limitations. Energy is the major problem in wireless sensor networks, and how to make the network live more time to ensure that the network communication quality is the ultimate goal. In this paper, aimed to extend the network life-cycle, a wireless sensor network for cross-layer protocol design method CLEED was put forward. CLEED make use of the data sharing of application layer, network layer and MAC layer to control the sleep time of nodes more precisely. At the same time, with the data shared by routing protocol, the packet latency caused by sleep of nodes can be reduced in MAC protocol. Simulation result shows that, CLEED exceed traditional protocol stack in network performance, especially the energy and network life cycle.