The Research On Routing Algorithms Based On Position Information In Sensor Networks

Wireless integrated sensor networks, which include collecting, managing data and communication, are used more and more widely for its low cost and convenient deployment. Nowadays the research concenrning each aspect of sensor networks is fairly active. Routing algorithm is one of key problems in sensor networks and this thesis have researched routing algorithm emphatically based on position.This thesis puts forward the concept of key nodes and divides different routing algorithms into two kinds, active and passive selection. Through suitable measures, we compare and analyze those characters. Flooding has low complexity, but its energy expenditure is too high. In order to resolve this problem, this thesis proposes a new algorithm based on limited flooding. Theoretic analysis and simulation results show that new algorithm can balance the complexity and energy expenditure effectively. Since the aim of forwarding the packets isn't too clear in the above algorithms, this thesis proposes another algorithm, curve-based routing algorithm (CBR), combining source-based routing and greedy forwarding strategy. Theoretic analysis indecates CBR is distributed and has low complexity. Furthmore, simulation results prove the validity of greedy forwarding strategy and the character of balancing energy expenditure of nodes. In order to resolve the problem of data redundancy and energy waste when all nodes, whose density is too large, work together, this thesis proposes an energy-saved algorithm which combines density control and the structure of grid. The new algorithm only selects some nodes to work and others to sleep which will be wakened to replace dead nodes at approprate time. Simulation results show the method of selecting working nodes is effective and can reduce the number of working nodes. Aiming at the requirement of security, this thesis researches the attack to sensor networks and protecting measures and then proposes a secure routing algorithm based on multipath. The new algorithm synthesizes those proposed method of encryption, authentication and integrality-validation and provides additional security using multipah. Theoretic analysis and simulation results show that new algorithm can provide security to some degree and high probability to ensure at least a correct copy to the destination when part of nodes have been attacked and invalidated.