Anchor Node Failure Based Localization Algorithm Research In Underwater Wireless Sensor Network

With the development of society, people explore more issues about nature. Ocean exploration is one of the most important part in nature exploitation. It is so difficult to explore under the water for the complex environment, so the underwater wireless sensor network makes it possible to explore under the water. But the complexity of underwater environment and so many uncertain factors make underwater exploration a huge challenge.Localization is an important part of underwater wireless sensor network. It makes data meaningless if node doesn’t know its location. Many situations possibly will make anchor node fail. Anchor nodes failure could reduce the localization coverage and localization accuracy. This paper puts forward a localization algorithm to reduce the effects of nodes failure. When nodes could not locate themselves they broadcast the messages which notify they can’t locate themselves. When located nodes received the messages they become reference nodes. Then they broadcast theirs location information to help the nodes which can’t locate. When the unknown nodes receive more than three location information they pick up the location information with higher accuracy to locate themselves. Then the localization reference nodes fade into ordinary nodes. According to the simulation, this algorithm can effectively improve the localization coverage and relieve the impact caused by anchor node failure.This paper makes localization experiments in underwater wireless sensor network based on ZigBee system. Except the process of system construction, this paper introduces the localization based on prediction in the condition of water flow and analyzes the data tested from the system. The result shows that the algorithm can reduce the localization frequency and save the energy.