On Cost-Effective Routing Schemes for Wireless Networks

• Main Authors: Ming-CheChen, 陳銘哲
• Other Authors: Hui-Tang Lin
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/05921772808958334919

博士 === 國立成功大學 === 電腦與通信工程研究所 === 103 === This dissertation is aimed at addressing critical issues of designing cost-effective routing protocols in order to enhance different performances (i.e., decreasing communication cost for improving energy-saving performance, reducing end-to-end delay cost for increasing throughput performance) over various wireless networks (i.e., Wireless Sensor Networks (WSNs), and Wireless Mesh Networks (WMNs)). WSNs make possible many new applications in a wide range of application domains. Many of these applications are based on a many-to-many communication paradigm in which multiple sensor nodes send their sensed data to multiple sinks. To support these many-to-many applications, this dissertation proposes an energy-efficient transport protocol in which each source sensor evaluates the multicast costs of various potential multicast trees between it and the destination sinks and then selects the tree with the minimum communication overhead. The simulation results demonstrate that the proposed multicast routing algorithm yields a significant reduction in the total energy consumption, and therefore enables a notable improvement in the network lifetime. Spillages of pollutants such as oil or biochemical materials at sea have the potential to damage not only the offshore environments, but also the regional economy. In order to monitor spilled pollutions in the real-time, continuous, and energy-efficient fashions, this dissertation develops an aquatic-pollution detection and tracking scheme, designated as AquaView, based on a WSN deployed over an offshore region (i.e., a Waterborne Wireless Sensor Network (WWSN)) to track the moving boundary of a pollution spill such that cleanup operation can be effectively monitored and controlled. In evaluating the boundary tracking performance of AcquaView, a 3D Floating Mobility Model (3D FMM) is used to simulate the movement of the sensor nodes floating on the ocean surface. The numerical results confirm that the 3D FMM model accurately reproduces the statistical features of the ocean current, wind and surface wave effects on the 3D trajectories of the sensor nodes. Moreover, it is shown that AquaView achieves a significantly improvement in a satisfactory boundary estimation performance and a low communication cost. Anypath routing has been proposed as a means of enhancing the performance of WMNs by exploiting the inherent broadcasting and spatial diversity properties of a wireless medium. Previous studies have focused on the problem of identifying an appropriate forwarding set at each node based on the packet delivery ratios of the wireless links within the network. However, the schemes proposed in these studies may result in a significant degradation of the throughput performance since they ignore the potential Expected Packet Transmission Time (EPTXT) overhead incurred by the nodes in contending for the shared channel resources in order to transmit a packet to its forwarding set. Accordingly, this dissertation proposes an analytical model for estimating the end-to-end delay of a node in delivering a packet to a given destination via its forwarding set based on the EPTXT of the node and G/D/1 queueing theory. A Cross-layer Anypath Routing (CAR) scheme is then proposed for determining the most suitable forwarding set at each node based on an Expected Time of Anypath Transmissions (ETATX) metric, as determined by the EPTXT of each node along the anypath and the packet delivery ratios of the corresponding links. The numerical results confirm that the proposed analytical model provides an accurate estimation of the end-to-end delay performance of a node in transmitting a packet along an anypath to the destination in light load regime. Moreover, it is shown that compared with existing anypath routing schemes, CAR results in a lower end-to-end packet forwarding delay, and therefore increases the throughput at each node.