Research On Qos Promoting Method For Heterogeneous Flow Priority Distinction In 4G Network

With the development of LTE(Long Term Evolution)network,the transmission capacity of wireless network has been greatly improved.At the same time,the multimedia services become more and more diversified,such as VOIP,WEB,Video,etc.We need to distinguish different service priorities to provide QoS(Quality of Service)protection and it has become a new research hotspot in the industry.Besides considering the channel quality,we should take into account the QoS requirements of multimedia services.Therefore,we can provide QoS protection through distinguishing the flow priorities.Now,this method has been a hot issue on resource management.This thesis introduces the existing scheduling algorithm and active queue management method,also points out the shortcomings,further analysis and improvement.On this basis,the following results are obtained:In view of the current scheduling algorithm,a multi-priorities scheduling algorithm named MP-MLWDF(Multi-priorities Modified Largest Wait Delay First)is proposed,which is based on the priority of heterogeneous flows.Meanwhile,the MP-MLWDF can improve the throughput of whole system and the transmission quality of flows.Aiming at the deficiency of linear probability function,a concave probability function and a convex probability function are proposed to replace the traditional linear probability function.The queue dropping probability is set up according to the size of the average queue length,which improves the average throughput and reduces the number of forced packet drops.Based on the improvement of the active queue management algorithm,a priority-based queue management algorithm MP-SmRED(Multi-priorities Smart RED)is proposed,which can adjust the drop probability function dynamically according to the number of packets in different queues.The MP-SmRED can reduce the queue resource redundancy and improve the performance of queue management.