| Summary: | 博士 === 淡江大學 === 資訊工程學系博士班 === 104 === In wireless sensor networks (WSNs), the deployment and communication issues are very important and have received much attention in the last decade. This thesis mainly proposes efficient deployment and communication algorithms for improving the operating efficiencies of the wireless sensor networks.
First of all, the goal of developing a deployment algorithm is to deploy sensors in a given monitoring region in a way of low hardware cost and high coverage quality. In recent years, several mechanisms were developed for robot to deploy sensors efficiently. Their performances highly depend on the obstacles since their results are always inefficient when the Dead-End problem is encountered. Therefore, it has been the key challenge for developing a robot deployment mechanism to overcome the Dead-End problem and satisfy the full coverage requirement by using minimal number of sensors. This study proposes an Impasse-aware robot deployment algorithm, called IAD. The proposed IAD mainly consists of basic deployment rules and Dead-End handling rules. The basic deployment rules try to use minimal number of sensors such that the full coverage purpose can be achieved. Moreover, the proposed Dead-End handling rules can efficiently deal with the Dead-End problem. Extensive experiment studies show that our proposed IAD has better performance than existing robot deployment mechanisms in terms of coverage ratio, energy efficiency, deployment path length as well as required stack space.
In addition to investigating the deployment issue, this thesis also investigates the communication issues in WSNs. The Multi-channel media access control (MAC) protocols can increase wireless network capacities. The rendezvous problem is the most frequently encountered challenge in developing multi-channel MAC protocols. Some studies have assumed that each device is equipped with one additional antenna; however, this increases the hardware cost. Other studies have divided the timeline of each channel into several beacon intervals. All stations are awake simultaneously on a predefined channel to enable rendezvous opportunities; however, this leads to low bandwidth utilization. This thesis also presents an efficient staggered multichannel MAC protocol (SMC-MAC) for ad hoc networks. By using a single antenna, the proposed SMC-MAC applies a staggered channel model with a home channel concept for exploiting multi-channel bandwidth resources. Performance results reveal that the proposed SMC-MAC outperforms existing multi-channel MAC protocols in terms of network throughput, control packet collision ratio, packet delay time, packet discarding, packet loss ratio, control overhead, and robustness.
In summary, this thesis proposes robot deployment algorithm and MAC protocols for improving the efficiencies of the WSNs. Extensive experiment studies show that our proposed IAD has better performance than existing robot deployment mechanisms in terms of coverage ratio, energy efficiency, deployment path length as well as required stack space. In addition, the performance results reveal that the proposed SMC-MAC outperforms existing multi-channel MAC protocols in the network throughput, control packet collision ratio, packet delay time, packet discarding, packet loss ratio, control overhead, and robustness.
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