Topology Control And Its Applications In Wireless Sensor Networks

Wireless sensor network (WSN) is composed of a large number of sensor nodes, and by way of self-organization, which is used to connect the physical world, information world and the human. Since WSN is suffered from stringent energy constraints, energy saving has always been the core issue and a major challenge. Topology control technology is used to solve problems in building network topology by self-organization, which is one of the important technologies to reduce inter-node communication interference, reduce the network energy consumption and prolong the network life. Several topology control algorithms, sleeping scheduling strategies, and converge-cast protocols are proposed in this thesis in order to satisify the needs in different design purposes and the application demands under the limit of sensor node energy capacity and the condition of high density deployment. The main research works and achievements are summarized as follows:In the field of topology control, the Connected Dominating Set (CDS) based Virtual Backbone (VB) is a well-known high efficient topology control structure. Based on CDS, the Induced Trees of the Crossed Cube (ITCC) is defined in this thesis. The unique Fibonacci characteristic is employed to design the distributed Induced Trees of the Crossed Cube (CDS-ITCC-G*). Moreover, by combining the Crossed Cube and the well expending Ring structure, the Crossed Cube Ring based k-CDS Construction Algorithm (CCRA) is proposed conditional on the support of the k-CDS fault tolerance, the k-connectivity from the k-Crossed Cube, and the fragileness of Wireless Sensor Network. Giving the target tracking as the object, the theory and the experimental results indicate that our proposed method is capable to produce the optimal CDS and k-CDS.On the other hand, the sleeping scheduling method is an important technique for the energy saving. It allows parts of the redundant sensor nodes to fall into the sleeping mode and actives only partial of the sensor nodes in the whole network. Two sleeping scheduleing strategies are proposed in this thesis:The first strategy aims for achieving the maximum coveragy and the connectivity. It transforms the problem of finding the maximum network life time into the problem of finding the maximum Connected Dominating Partition. The Schedule scheme-ITCC based partition algorithm (IPAS) is proposed in this thesis. The theory and simulation analysis indicates that the IPAS is capable to find the upper bound of the CDP and is available to extend the life time of the network. Moreover, Dec-Partially Observable Markov Decision Process based Sleep Scheduling Scheme (Dec-POP-S3) is proposed to solve the issue of the target tracing. The theoretical proof is given in the thesis and the upper bound of the reward is revealed. The numerical analysis shows that the maximum reward can be obtained by applying Dec-POP-S3 in the network.In addition, the maximum coding number is the important index of forwarding rate in Converge-east. However, the time delay is unavoidable when the coding number increases on the coding node. Since the acceptable delay time must be constrained in a feasible range, the balance between the coding number and the caused time delay is an issue need to be considered in the Coverage-cast network. To satisfy the demand mentioned above, the Coverage-cast Scheme based on data Rate Prediction (CSRP) is proposed in this thesis. The theory provides and the simulation result indicates that the suboptimal balance point can be found by CSRP with high coding number and the data lossless condition.