Integrated circuits, micro electromechanical systems and the development of communication theory led to the emergence of wireless sensor networks [4]. This wireless sensor network is composed of many sensor nodes self-powered. Each sensor node can be collected, simple computing environment data and to communicate with other nodes and the outside world. The sensor node characteristics of sensor networks make many
environmental interference and node failure caused by the change of the network topology; in general, most of the network node is fixed.
The majority of distributed MAC protocol uses carrier sense or collision avoidance mechanism and the use of additional signaling information to solve the hidden and exposed node problem. Competition is a random access MAC protocol based on nodes need to transmit data, using the wireless channel by means of competition. IEEE802.11 MAC protocol based on Carrier Sense Multiple Access with collision avoidance (Carrier Sensor Multiple Access with Collision Avoidance, CSMA/CA) is based on MAC protocol is a typical competition. Based on IEEES02.11 MAC protocol, the researchers put forward many sensors for sensor network contention based MAC protocol, S-MAC protocol, T-MAC protocol: for example, ARC-MAC protocol, Sift- MAC protocol, Wise-MAC protocol [5].
sensors can be made of high quality through collaborative work, and consists of a collection of good fault tolerance of the system. It is because of
these advantages, in recent years there have been many wireless sensor network applications based on distributed detection and rescue, emergency rescue and disaster relief, intelligent home furnishing such as chemical and biological weapons attacks, as is shown by equation 2.
Wireless sensor network architecture consists of
three main parts: the sensor node, terminal node (Sink) and object of observation. Sensor nodes scattered collection and observation of the object of related data observed in the region, and after coordination to deal with data transfer to Sink. Sink can realize the communication of sensor network
The network layer is responsible for routing lookup and packet transmission. Since a large
The use of radio frequency module, there are two problems to be paid attention to: the first is when the transmission is completed, must send the enable pin and transmit data pin is set to low level. Otherwise one will consume energy, on the other hand, the RF module will always send a single carrier frequency signal, the disturbance to the surrounding nodes work; second is the wireless transmission module to transmit state from the standby state, there are about
20 s between the delay. In the meantime, input module data cannot be sent correctly, so ready to send before, should be sent to set high in advance.
Wireless ad hoc networks (mobile Ad-Hoc network) are a kind of tens to hundreds of nodes by
number of nodes in a sensor network deployment group are random, so look at the mesh network of multi-hop routing is very difficult, when the node failure or redeployment route maintenance and repair (self-healing) will be equally difficult. In the past few years there has been a large number of can support distributed routing algorithm for ad hoc mullion network. In general, these routing algorithms can be pided into two categories: active (proactive) and passive (reactive). In a proactive routing protocol, all nodes in the network are often maintained a route between the source address and destination address list, regardless of the need of these routing.
multi-hop, mobile wireless communication network, dynamic peer-to-peer network. Its purpose is to ZigBee技术无线传感器网络英文文献和中文翻译(3):http://www.chuibin.com/fanyi/lunwen_206557.html