The Research On Routing Protocol Of Agricultural Environmental Monitoring System Based On Wir Eless Sensor Networks

Wireless sensor network technology integrated four main technologies: microelectronics technology, wireless communication technology, embedded computing technology and sensor technology, this technology provides a new technology for data information collection, processing and transmission in practical applications. Wireless sensor network which have characteristics suck as environmental adaptability, self-organizing, dynamic adaptability, application correlation etc, that makes this technology can satisfy the different application needs. From military field, space exploration, radiation detection, flood warning, farmland management etc field to household appliances automation, patient real-time monitoring etc field can realize through wireless sensor network technology.At present our country agriculture is in the key period of transformation from tra- ditional to modem agriculture, the development of information technology and appli- cation provides the revolutionary role for it. Thereinto, the sensing technology and intelligent information processing is important means that ensure correct quantitative gain agricultural information .This method is compensated for the shortcomings of previous data monitoring . Because of farmland environment is provided with broad monitoring area , High real-time , Bad environmental and long experimental cycle, the permanence of The sensor node power supply would be a higher requirement.If one node can't work on due to no power,especially the pivotal node,the datas of farmland environment monitoring system would be unreal.Therefore,the key of choosing the routing-protocol is how to equilibrium the power cnsumption,in order to extend the lease of the system.This paper put forward one routing algorithm base on energy equilibrium,accrding to the practical application of farmland environment monitoring system,on the basis of Analysis and comparison of the existing wireless sensor network routing protocol.The primary researches and innovation linculding the following aspects:(1) Using cluster-heads rotation mechanism. The cluster-heads selecting is not periodically rotation,but into consideration on the remaining energy of the cluster-heads and select the codes have a certain amount of surplus energy as cluster- heads. After the construction of cluster,setting a energy threshold in the cluster in order to realize the cluster-heads rotation mechanism.Comparing the left power of the cluster-head with the energy threshold,if the power is less, the new choosing about the cluster-head will beging.Only the left power of the other nodes is not less than the energy threshold,they could be the cluster-heads.Of course,if the left power of the cluster-head is more than energy threshold,the change is not required.(2) We adopt TDMA to communicate in the cluster.The senor nodes are primarily in charge of the real-time monitoring of the environmental information and senting the data to cluster-heads.Every code entirely sents data to the cluster-heads.However,the data of the nodes only transport one by one.So one slot table is necessary which assigns different time for the transmission of every node in the cluster.If the data of one node is transporting, the other nodes can shut down their wireless transceivers so as to save the power.(3) During the clusters, the transmission will adopt the multi-hop mode.Considering the monitoring area of farmland are vaster,the energy consumption of the long distance from clusters to base station is more.That can lead to use the power up.Therefore,the transmission routing among the cluster should be built firstly before transporting data to base station.The data will be transported down the routing until arrive the base station on level.