Research And Design Of Queue Management Mechanisms Of 10 Gigabit Coaxial Access System

With the implementation of the national strategy for broadband in China,accelerating the construction of indoor high-speed communication channels has become the key to the development of the information field.HINOC is a new broadband access solution with complete intellectual property rights developed for the characteristics of China's wired and coaxial networks.The HINOC3.0 under development will be able to reach 10 Gigabit access capabilities,comparable to international advanced coaxial access technologies performance.Since HINOC is a typical TDD/TDMA system,when data arrives at HINOC device,it must wait until the time slot allocated by the system arrives before it can be modulated onto the coaxial.Therefore,it is one of the important factors affecting the network performance to set a queue management suitable for 10 Gigabit bandwidth in HINOC MAC layer to manage and coordinate the data frames sent to different devices.Based on the in-depth study of current HINOC technology,this thesis proposes a simple queue management method based on dynamic threshold.Aiming at the disadvantage that the queue management method based on dynamic threshold will waste a certain amount of cache resources,two queue management methods based on virtual threshold design are proposed: a queue management method based on service level agreements to set virtual thresholds designed for scenarios where users have differentiated bandwidth guarantee needs,and a queue management method based on user historical captains setting virtual thresholds designed for scenarios where users have a uniform bandwidth rate.In order to verify the effectiveness of the queue management method proposed in this thesis,these three queue management methods are designed and implemented based on the MAC layer simulation platform,and a variety of scenarios are designed to simulate and analyze the performance of these three queue management methods.The simulation results show that the queue management method based on dynamic threshold adjusts the threshold of the cache shared area of each priority queue through the threshold rebound and backpressure mechanism according to the queue length,has the advantages of high cache utilization rate and can effectively reduce the high priority data packet loss rate when the cache resources are tight;The queue management which set different virtual thresholds based on service level agreements has the advantages of high cache utilization rate,almost not discarding high priority data when the cache is tight,and can provide excess bandwidth services to some users as much as possible while ensuring all users purchased bandwidth;the queue management method which set the virtual threshold based on the historical threshold of the queue calculates the virtual threshold of each queue in real time according to the historical length of each queue,has the advantages of high cache utilization rate,almost not discarding high priority data when the cache resources are tight,being able to guarantee the normal cache use of uniform services at the same priority rate as much as possible when the cache resources are tight and restraining the impact of burst services at the same priority to the normal services.The three queue management methods proposed in this thesis are designed for the actual working scenarios of the 10 Gigabit coaxial access system,and have reference value for the research of the queue management of the 10 Gigabit coaxial access system.