Modified largest weighted delay first （M-LWDF） is a typical packet scheduling algorithm for supporting hybrid real-time services over wireless networks. However, so far, there is little literature available regardin...Modified largest weighted delay first （M-LWDF） is a typical packet scheduling algorithm for supporting hybrid real-time services over wireless networks. However, so far, there is little literature available regarding the theoretic analysis of M-LWDF fairness. This paper gives a theoretic analysis of M-LWDF fairness, which shows that M-LWDF fairness is related to channel condition, packet＇s arrival process and the ratio of quality of service （QoS） requirements of different service queues. Given service QoS requirements and other parameters related to channel model and packet＇s arrival process, the fairness is merely related to the ratio of the number of users in the service queues. Based on the analysis, an enhanced M-LWDF algorithm （EM-LWDF） is proposed and demonstrated in this paper. EM-LWDF is strictly designed in light of the fairness criteria of QoS requirements, so its fairness is almost not related to the ratio of the number of users in the service queues, and the theoretical value of fairness index is equal to 1. Simulation results validate the theoretic analysis and show the effectiveness of EM-LWDF in improving fairness.展开更多
长期演进系统(long term evolution,LTE)中的分组调度算法需要满足一定的QoS。针对最大权值时延优先算法(modified large weighted delay first,M-LWDF)在用户公平性方面的缺陷,提出了基于线性优先级和非线性优先级的M-LWDF算法,以达到...长期演进系统(long term evolution,LTE)中的分组调度算法需要满足一定的QoS。针对最大权值时延优先算法(modified large weighted delay first,M-LWDF)在用户公平性方面的缺陷,提出了基于线性优先级和非线性优先级的M-LWDF算法,以达到提升用户公平性的目的。仿真结果表明,所提出的算法能够在牺牲少量系统吞吐量的情况下,较大程度地改善用户公平性和业务的丢包率。展开更多
基金supported by the National Natural Science Foundation of China (60972068)the Basic Application Research Program of Chongqing Education Committee of China (KJ090502,KJ100517)+1 种基金the Graduate Innovation Program of Chongqing University of China (200904B1A0010306)the Youth Program Foundation of Chongqing University of Posts and Telecommunications of China (A2008-28)
文摘Modified largest weighted delay first （M-LWDF） is a typical packet scheduling algorithm for supporting hybrid real-time services over wireless networks. However, so far, there is little literature available regarding the theoretic analysis of M-LWDF fairness. This paper gives a theoretic analysis of M-LWDF fairness, which shows that M-LWDF fairness is related to channel condition, packet＇s arrival process and the ratio of quality of service （QoS） requirements of different service queues. Given service QoS requirements and other parameters related to channel model and packet＇s arrival process, the fairness is merely related to the ratio of the number of users in the service queues. Based on the analysis, an enhanced M-LWDF algorithm （EM-LWDF） is proposed and demonstrated in this paper. EM-LWDF is strictly designed in light of the fairness criteria of QoS requirements, so its fairness is almost not related to the ratio of the number of users in the service queues, and the theoretical value of fairness index is equal to 1. Simulation results validate the theoretic analysis and show the effectiveness of EM-LWDF in improving fairness.
文摘长期演进系统(long term evolution,LTE)中的分组调度算法需要满足一定的QoS。针对最大权值时延优先算法(modified large weighted delay first,M-LWDF)在用户公平性方面的缺陷,提出了基于线性优先级和非线性优先级的M-LWDF算法,以达到提升用户公平性的目的。仿真结果表明,所提出的算法能够在牺牲少量系统吞吐量的情况下,较大程度地改善用户公平性和业务的丢包率。
