Boundary Recognition Algorithm In Location-free Wireless Sensor Networks

Wireless sensor networks (WSNs) comprise a group of millimeter-sized, well-equippedMEMS device, This micro-device includes sensors, a wireless transmitter and receiver, thepower supply, they are covered in a physical geographical area to monitor the area. thenetwork has a calculation processing capability, The sensor networks using micro sensornodes to obtain information between network nodes with automatic organization andcoordination ability to work within the network by way of wireless communications, Thesensor networks using micro sensor nodes to obtain information between network nodes withautomatic organization and coordination ability to work within the network by way ofwireless communications, Compared with traditional single large sensor or wired sensornetworks, with high accuracy, flexibility, high reliability, economy and good advantage.Wireless sensor network boundary detection is one of wireless sensor network applicationsservices support application technology, In some WSN applications, recognizing boundarynodes is important for topology discovery, geographic routing, tracking and guiding.In this paper, we study the problem of identifying the boundary nodes of a WSN. In aWSN, close-by nodes can establish direct communications with their neighbors and have theability to estimate distances to nearby nodes, but not necessarily the true distances. Ourobjective is to fnd the boundary nodes by using only the connectivity relation and neighbordistance information without any other knowledge of node locations.We propose a heuristic algorithm to fnd the boundary nodes which are connected in aboundary cycle of a location-free, low density, randomly deployed WSN. We develop the keyideas of our boundary detection algorithm in the centralized scenario and extend these ideas tothe distributed scenario. The distributed implementation is more realistic for real WSNs,especially for sparse networks when all local information cannot be collected very well due to sparse connectivity. In addition, the distributed implementation can tolerate faults byrecomputing the boundary locally when a boundary node is faulty. The article also presents anew distributed algorithms about wireless sensor network boundary detect, combiningknowledge of geometry and topology, based on the expansion of the polygon directed treesurrounded detection algorithm, the algorithm have no limits for the density of the networknodes, the simulation results show that the algorithm can effectively avoid the error detection,the occurrence of undetected cases, discrimination method is simple and accurate, greatlyimproving the wireless sensor network edge detection efficiency and accuracy.After the article in the knowledge of geometry and topology of the premise of combiningknowledge presents a wireless sensor network edge detect new distributed algorithms, basedon the expansion of the polygon directed tree surrounded detection algorithm, the algorithmfor the density of the network nodes no limits, simulation the results show that the algorithmcan effectively avoid the error detection, the occurrence of undetected cases, discriminationmethod is simple and accurate, greatly improving the wireless sensor network edge detectionefficiency and accuracy.