Research On Improved Localization Algorithm Of Wireless Sensor Network Node Based On OMNeT++

Wireless sensor networks extend people’s ability to obtain information, and connect physical information of the objective world and transmission network together. It will provide people the most direct, effective and real information in the next generation network. And it has very broad application prospects, which will give us a ubiquitous and intelligent network world. In wireless sensor networks, the location information is essential for monitoring activities. So the uncertainty of its nodes location may bring about challenges to the whole sensor networks. Therefore, determine the location of the incident and get nodes’ location messages is one of the most basic functions, which plays a pivotal role in the effective application of the wireless sensor network.The easiest way to obtain the location information of the nodes is installing Global Positioning System(GPS) on each sensor node. However, the GPS system not only has high cost of hardware and power consumption, but also does not have extensive adaptability to the environment. Therefore, the positioning algorithm has become an effective solution for wireless sensor network node localization. The localization algorithm based on non-ranging has become research focus because of no additional hardware, high positioning accuracy and extensive adaptability to the environment. In this paper, the classical localization algorithm DV-Hop is studied and the causes of the Dv-Hop algorithm error are analyzed. It is found that the exit of solitary nodes is an important factor affecting the positioning accuracy. And the trilateration used in calculating the unknown node, which is an important reason to affect the positioning accuracy because of the poor stability and low calculation accuracy used in it.Modified method is proposed for the two important reasons caused by positioning error of the above Dv-Hop algorithm. Firstly, determine the unknown nodes which are closer to the anchor nodes by RSSI ranging method, then upgrade them to anchor nodes thereby so that increase the number of anchor nodes and reduce the error because of distance. Secondly calculate the position of the unknown nodes by the free search algorithm rather than the trilateration algorithm.OMNET++ simulation shows that the improved algorithm is superior to the traditional algorithm, it improves in positioning coverage scale and the stability of network location and reduces the positioning error rate.