Research On Error Control And Topology Control In Wireless Sensor Networks

Wireless sensor networks (WSN) is an emerging area of computer science, driven by advances in MEMS micro-sensors, wireless networking, and embedded processing. WSN is constructed by small, low-cost and low-power sensor nodes deployed in large quantity, and it is self-organized network in wireless multi-hop mode. WSN can be used in environmental monitoring, military applications, medical treatment and so on.The power of sensor nodes supplied by batteries is high-limited and not easy to complement. Therefore, the most important issue in WSN is saving energy and prolonging network lifetime through power-efficient strategy.The main research contents and innovations in this dissertation are as follows:(1) Error control strategy for wireless sensor networks is studied on the view of energy efficiency. A BCH/CRC mixed Error-control code algorithm proposed in this dissertation combines the strongpoint of BCH and CRC code. When no error happens in transmission, only CRC check is executed, while complicated BCH code is avoided, so the processing energy of sensor node is saved. When some error happens, BCH code is executed to check error and data packets retransmission is avoided, so consumed energy in transmission is mitigated. BCH/CRC mixed Error-control code algorithm can efficiently save sensor nodes energy in channel with high or low BER (bit error rate), therefore its performance is better than ARQ and FEC in energy efficiency. With its strongpoint, BCH/CRC mixed Error-control code algorithm is feasible to use in WSN where energy is constrained and BER is varied .(2) DRNG (Directed Relative Neighborhood Graph) is a localized topology control algorithm for heterogeneous wireless sensor networks with non-uniform transmission range. It is proved that the network topology generated by DRNG preserves connectivity, bi-directionality and energy efficiency. But DRNG has high computation complexity when the antenna pattern is isotropic. In this dissertation, a modified DRNG algorithm is proposed to mitigate the complication of DRNG. The analyze results show that the modified DRNG algorithm reduces the number of visible neighbor nodes needed to confirm and the range of searching middle node in confirmation of neighbor nodes. So the modified DRNG algorithm improves the implement efficiency and saves the processing energy of sensor nodes.