The Research Of Anti-Collision Algorithm And Routing Protocol Based On RFSN In Intelligent Public Transportation System

Radio Frequency Identification (RFID) is a non-contact automatic identification technology which is a two-way communication, identification and exchange of data. Wireless sensor networks (WSN) is a multi-hop ad hoc networks which is formed by a large number of wireless sensor nodes deployed in the detected region and contact by the way of wireless communication, able to sense the surrounding environment parameters, collect, fuse and transmit data. Technical characteristics of each RFID and WSN, bring an opportunity for the integration of them. It is important to develop a new type of RFSN network that integrating with RFID’s automatic identification technology and WSN’s collect the surrounding environment parameters.This topic based on the intelligent transportation system, combined RFID and WSN effectively, constructed the framework of system for the fusion network, carried out the research of tag anti-collision algorithm and network routing protocol, aiming at balancing load of the network and prolonging the life cycle of the network.According to the requirements of identification efficiency high and transmission data less of reader in RFSN network, this paper proposed an improved hybrid query tree anti-collision algorithm after analyzing the binary search algorithm. The algorithm is based on query tree algorithm and introduce a slot compensation mechanism, make a preprocessing before the tag was identified, which extracted the tag’s collision bits and form a nee ID sequence to reduce idle prefix number; through bitwise XOR on the label further divided into sub-sets to improve recognition efficiency.Wireless routing protocols in intelligent transportation system requires low energy consumption, load balancing, long life cycle of the network, so an improved Ant Colony Algorithm-Direction Diffusion was proposed. Introduced the ant colony algorithm, at the same time, in the data transfer phase, the probe packet is no longer flooding way to transfer, but build a gradient to guide probe packets forward according to the concentration of residual on the path and the test energy and hops of the node until they reach the sink node. This algorithm not only reduces energy consumption, but also balance load of the network.The simulation results show that the enhanced algorithms are feasible. Improved anti-collision algorithm based on RFSN networks has less amount of data in transmission, less idle prefix number and smaller identification delay compared with traditional QT algorithm, HQT algorithm and greatly improving the efficiency of the algorithm recognition. IACA-DD proposed algorithm, compared with the DD algorithm, ACA-DD algorithm, although the transmission delay is slightly larger, but well-balanced network complexity, reducing the energy consumption of sensor nodes to achieve a non-urban roads intermittent monitoring, reducing the number of replacement sensor node.