Research On QoS-based Opportunistic Routing In Wireless Multi-hop Networks

Wireless multi-hop networks have unique properties such as self-organization, dynamic changes of the networks topology, multi-hop links, distributed computing, limited energy consumption, bad network environment and so on, so the design of wireless multi-hop networks faces enormous challenges. Especially, present quality of service assurance technologies cannot satisfy the needs of service, with the service of wireless multi-hop networks’constantly enriching. The quality of service(QoS) is mainly influenced by two contradictory factors, the validity and reliability of the networks. Traditional optimization methods focus on only one of them, but the other factor will be restrained. In addition, the traditional methods have not yet considered the characters of broadcasting and time-varying in wireless networks. So the quality of service is not very good. The quality of service assurance in wireless multi-hop networks is a research hotspot all the time.The thesis researches the problem of the quality of service assurance in wireless multi-hop networks, and the main contributions are as follows:First of all, the thesis builds a system model for wireless multi-hop network based on its application scenarios. Then an evaluation parameter is proposed through analyzing the factors influencing the quality of service in wireless multi-hop networks. These studies lay the foundation for the algorithm design and quality of service evaluation in later chapters.Second, the thesis analyzes opportunistic routing’s advantages compared to the traditional routing, through researching opportunistic routing in wireless multi-hop networks. Through studying the character of data forwarding’s uneven in wireless multi-hop networks conforms with the pareto distribution(20-80 principle), the thesis proposes an adaptive opportunistic routing(AOR) based on the status information in wireless networks. AOR can adaptively adjust the data transmission path in order to reduce the transmission delay and improve network throughput according to the wireless networks’status information. The simulation experiment results prove that AOR can provide lower transmission delay than traditional opportunistic routing.Third, inspired by the cross-layer cooperation, the thesis proposes QoS-aware Forward Error Correction cooperation with AOR(QFEC-AOR). With utilizing the status information of the wireless networks, QFEC-AOR can adaptively adjust the information transmission route and the anti-interference of data transmission to balance the validity and reliability of the networks. The simulation experiment results prove that QFEC-AOR can improve the quality of service effectively in wireless multi-hop networks.