Study On Multicast, Routing And Location Management For Wireless Sensor Networks

Wireless sensor network (WSN) has been a new research area for some years. WSN consists of a large amount of wireless sensor nodes integrated with sensing, computing and communication modules. It senses information from physical world and transmits the messages to the users. The features of self-adaptive, ruin-resistant, easy deployment and low cost enable WSN to conduct many special applications, such as environment surveillance, multimedia service, smart homing and military application. To improve WSN's multicast performance, ensure its availibility and guarantee the fault-tolerance is. an important issue for mobile WSN. This thesis focuses on multicast routing, location management, quorum construction algorithms and delivery in ICWSN (Intermittently Connected Mobile Sensor Networks). The main contributions of the thesis are as follows:(1) A shared tree algorithm for bilaterally filtering multicastA bilaterally filtering multicast routing algorithm for multicast service is proposed for wireless multi-hop ad hoc networks, satisfying constraints such as end-to-end latency, bandwidth limit and node-stability. The proposed algorithm is based on MAODV, a shared-tree multicast algorithm, and can reduce the routing cost through bilaterally filtering the invalid and inefficient routing path. The simulation results show that the improved protocol reduces average routing cost and increase the stability for mobility of nodes.(2) A quorum based route repair for shared tree multicast in mobile WSNThe mobility of recipient in multicast process is easy to break away link between it with multicast tree. Some realtime applictions, however, require quick route repair to link recipient to multicast tree. We propose a quorum-based route repair for shared-tree muliticast. This scheme provides a mechanism of quick looking-up rendezvous point for recipient and establish route between it and multicast tree. Results obtained through simulations demonstrate that the algorithm reduces switch time and average routing cost.(3) Irregular Grid Quorum Based Location Management for Wireless Sensor NetworkLocation service provides position of mobile destination to source node so that position based routing can be applied. Several quorum-based location services have been proposed. We propose a novel irregular grid quorum based location service. In the proposed scheme, location databases are stored in the network nodes themselves, which form a self-organizing virtual backbone network. Quorum system is constructed on the virtual backbone network in conformity to irregular grid rule. Every mobile node will notify its location update information to irregular grid quorum system so that other hosts can obtain the other node's location through irregular grid quorum system. The simulation results show that our proposed location service leads to low switch time, and low control cost.(4) K-Anycast Quorum-based location management in wireless sensor networkWe present a novel algorithm for location management in wireless sensor network, which called K-anycast-based irregular grid quorum location management. K-anycast irregular grid quorum doesn't require the quorum construction process in initialization, but choose the fastest nodes as quorum elements according to irregular grid rule in routing phase. The simulation results show that KLGQ can not only reduce the cost of location service, but also support more failure on quorum systems.(5) Interest Region-Based Delivery in Intermittently Connected Mobile Sensor NetworksThe mobility of nodes in Intermittently Connected Mobile Sensor Networks is normally with "small world dynamics",and its movement is restricted with some "interest".This paper propose a interest region-based delivery mode,named IRBD (Interest Region-Based Delivery,which first deliver message duplications to regions with high spread utility value, and through intrest-oriented algorithm, drag duplication to regions with higher interest value. Our results show, with respect to both message delivery ratio and delay, our scheme outperforms others in deterministic rouging enviroment.