Font Size: a A A

Research On Key Technologies Of Routing Protocol For Wireless Sensor Networks

Posted on:2010-07-09Degree:DoctorType:Dissertation
Country:ChinaCandidate:X ZhangFull Text:PDF
GTID:1118330332978702Subject:Communication and Information System
Abstract/Summary:PDF Full Text Request
In recent years, the rapid development in low power wireless communication, microsensor, in conjunction with the significant progress in distributed signal processing, ad hoc networks protocols, and pervasive computing have made wireless sensor networks (WSNs) a new technological vision. WSN is formed by large amounts of micro sensor nodes networking in ad hoc manner which collaboratively gather and deliver information from the objective area automatically. Routing protocol is the key technology of WSN for information gathering and collaboration among sensors.Routing protocol design differs from that in traditional wireless networks because of the limitation of network resource as well as the spectial traffic characteristics and various user demands in WSN. In this thesis, key problems in WSN routing protocol design are investigated including energy efficiency, bandwidth efficiency and transmission reliability. Main research fruits are summarized as follows:1. An Optimal Relay Ratio based Cooperative Routing (ORRCR) strategy is proposed to maximize the network lifetime of WSN in fading channel and under many-to-one traffic pattern which combins forwarding and cooperative transmission modes together. By quantitative analysis of the relationship of network lifetime and relay ratio, network lifetime maximization problem is transformed to relay ratio optimization. High nonlinear characteristic of this problem makes it difficult to obtain optimal solution directly. Through analysis on relationship between network lifetime maximization and equal energy consumption between nodes, important conclusions are reached that "network lifetime is maximized with all nodes and some nodes have equal energy consumption" which simplify the above optimization problem greatly. Distributed routing protocol DORRCR is proposed based on optimal relay ratio. It achieves longer network lifetime.2. A bandwidth resource efficient Collaborative QoS Rouing (CQR) strategy is proposed. The key of CQR is to jointly optimize path selections of multiple flows so as to overcome the bandwidth fragment problem resulted from path optimization focusing on one data flow. The problem is summarized as multi-commodity problem. But because of space coupling characteristic of path selection within multiple flows in wireless channel, classical algorithms can't work. Interfered Link Set oriented bandwidth resource decomposition is proposed to transform the routing optimization of multiple flows to optimization of resource decomposition vector and the optimal solution is obtained in centralized manner with subgradient optimization method. Because the centralized algorithm is of high computation complexity and is hard to be directly used in WSN, Local Traffic Migration based CQR protocol is proposed; through quantitative analysis of relationship of topology knowledge and local traffic migration success probability, key parameter is optimized. LTM_CQR achieves higher bandwidth efficiency comparing to existed protocol.3. Alice-Bob coding structure is studied in network coding aware routing algorithm. The condition under which paths of different traffics form Alice-Bob coding structures (AB condition, for short) is analyzed and series characteristic of two neighboring coding structure along one path is proved; A centralized Network Coding based Best effort Coupling Routing (NCBCR) algorithm is proposed, which adjusts paths of different data flows based on the AB condition and series characteristic to form as many as possible coding structures. NCBCR outperforms traditional aloghrithms by reducing end to end transmissions.4. A Virtual Multipath Reliable routing protocol is proposed. VMR doesn't send specialized probing packet for reliability information of wireless link; instead, it sends data packets along possible paths and gather path reliability information at the same time. Interval estimation is used to evaluate quality of the paths and bad path filter method is proposed to dynamically choose the optimal path(s). Simulation shows that VMR outperforms reliable routing protocol AODV_ETX in both energy efficiency and reliability.
Keywords/Search Tags:Wireless Sensor Network, routing protocol, network lifetime, bandwidth, reliability
PDF Full Text Request
Related items