Research On Reliable Routing Mechanism With Load-aware Consideration In Hybrid Optical-wireless Broadband Access Networks

Hybrid Optical-Wireless Broadband Access Networks(HOWBAN)is one of the most efficient solutions for "last mile" access,which combines the high-bandwidth,high-speed of passive optical networks and flexible networking,seamless coverage,mobile access of wireless mesh networks.However,the front-end wireless mesh networks with self-healing and strong volatility network state,the back-end passive optical networks can be remotely covered,but the tree topology is poor robustness,therefore,HOWBAN takes time to commercial.How to overcome the volatility state of the wireless domain,the sudden burst of optical domain and other defects that need to select a reliable path for data forwarding and can recover the faulty in time.Therefore,designing efficient initial routing strategies and backup routing strategies for coping with failures are critical to optimizing network performance and improving the user experience.Firstly,the fundamental and research status quo of HOWBAN are introduced,then the main routing mechanisms and their performance on reliable transmission are emphatically analyzed and compared.Secondly,how to select a low-congestion,high-quality initial route,a data forwarding strategy with node load awareness that considering the factors of node congestion and link continuity is proposed.By estimating the cache queue length and link signal to noise ratio to quantify the routing criteria for cross-domain transport paths,then use the entropy theory to calculate network state parameter weights and adaptively select the reliable transmission path.Numerical results shows,the proposed initial routing strategy can effectively improve the efficiency of data forwarding,and optimize the performance of load balancing and transmission delay.Thirdly,for the problem of service recovery after network failure,this thesis considers the choice of protection path in the perspective of optimizing the utilization of backup resources,a backup routing policy with connection availability constraints and low bandwidth consumption is proposed.By comparing the required path availability and the available probability of the initial route,constructs a conditional constraint model which classify the protection by different constraints according to the demand satisfaction of wireless domain and optical domain,to meet the needs of connections and the goal of optimize backup resource utilization,efficiently select protection resources for the initial route by the way of gradual optimization.Numerical results shows,the proposed backup routing strategy can improve the recovery rate of failures,backup resource utilization and throughput.Lastly,the research works of this thesis are concluded and the future works are presented.