The MAC Protocol Design Of Wsn With Sensors Non-Autonomous Moving And The Design Of Drift Trajectory Generation Algorithm

Wireless sensor network is made up of thousands of micro sensor nodes, and it is ad-hoc network that has a dynamic change topological structure. Because of its advantages such as low-cost, high monitoring accuracy and achieving long-distance message, it is highly put in use into environmental monitoring. This article proposed to apply WSN in debris flow monitoring, through deploying senor nodes in river bank and bed. On one hand, this system can forecast the arrival of debris flow. More importantly, we can achieve relative information. The information can form debris flow’s movement rule.This brings us to the question that traditional MAC protocol can not meet the demand of the WNS with sensors non-autonomous moving by debris flow. In debris flow environment, this paper proposed a MAC protocol design with sensors non-autonomous moving.The protocol has characteristics listed as follows:1. Sensors are non-autonomous mobile, receivers in river bank is cluster head, while other members are moving, this header manage their time slot, coordinate their time using for sending and receiving message and publish communication schedule.2. To response the arrival of debris flow, this paper proposed the priority mechanism, while a sensor node has a higher priority, the owner of current time slot must give up its slot, in this wav header can be informed the arrival of debris flow.3. Because this application is a early warning of debris flow and state monitoring, the protocol divide period into monitoring period and active period, in consider of energy conservation and prolonging system life cycle, monitoring period has sleeping phase.To increase network connectivity and develop MAC protocol performance, this paper also proposed a sensor drift track form algorithm. This algorithm is used to create nodes’ moving model, as a module of MAC protocol. Base on location and speed of sensor nodes drifting in river, the algorithm form a virtual track point by point.To test and verify, this paper use matlab as a simulation tool, collect the speed and direction generate by algorithm,compare the virtual trajectory and true trajectory, results shows that the virtual trajectory and true trajectory is matching in speed, direction distribution, they have internal consistency. To measure the match degree of virtual trajectory and true trajectory, this paper proposed rate of match as measure parameter, the higher the rate of match, the higher relevance of two trajectory sets, the rate of match can reach a steady value of 95%.