Study And Implementation On Encoding And Decoding Algorithm Of Data Collecting Protocol In Wireless Sensor Networks Deployed In Harsh Environments

In recent years, with the development of computer technology, network technology,embedded technology and wireless communication technology, Wireless Sensor Networks(WSN)develops rapidly. Wireless sensor networks are usually deployed randomly in the area where the environment is relatively harsh, such as deployed in the forest to monitor forest fire, in the battlefield to monitor enemy's situation.Because of these monitoring areas are in bad condition,the sensor nodes may be faced with unpredictable failures or sudden death. Considering the above problem, how to safely and efficiently deliver sensed data to the sink is a critical and challenging problem in such systems.Now the application of encoding technology in WSNs can improve the efficiency of data collection. Because of the fountain code are a kind of rateless code and their encoding and decoding algorithm are simple, they are very suitable to be used in WSNs. Growth Codes can effectively improve data persistence of the Zero-Configuration network. But the decoding speed of GCP is not enough, So a distributed data gathering protocol GC-BP is proposed for the large-scale distributed network that decodes the complex code set of the iterative decoder by two confidence decoding,and the simulation results show that it can effectively improve the collection rate of the data. GCP in the sparse network will cause uneven data distribution. So we propose a new distributed data gathering protocol RGC-GE that sort the neighbor node number, and then select the neighbor node for data exchange. Finally, we simulate RGC-GE with other protocols, the simulation results show that the RGC-GE protocol can effectively improve the reliability of data in sparse network.