共查询到20条相似文献,搜索用时 110 毫秒
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优先级队列(PQ)算法虽然能够保证高优先级业务的服务质量,但低优先级业务的性能较差,整体性能不佳,公平性较低。针对这些不足,提出优先级与带宽需求相结合的调度算法(PRQ),在优先级调度的基础上,使用带宽需求对调度概率进行调整,提高低优先级业务的调度概率,进而改善其服务质量,同时改善整体性能,提高公平性。仿真结果表明,PRQ算法能够显著改善低优先级业务的性能和整体性能,公平性较PQ算法高。 相似文献
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随着通信技术、计算机技术的迅猛发展,向用户提供视音频和数据服务业务,实现交互式全数字多媒体通信是技术发展的必然。以HFC信道和CM为主,论述DTV信道中交互数据服务业务的传送。 相似文献
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A cross-layer scheduling algorithm with QoS support in wireless networks 总被引:13,自引:0,他引:13
Scheduling plays an important role in providing quality of service (QoS) support to multimedia communications in various kinds of wireless networks, including cellular networks, mobile ad hoc networks, and wireless sensor networks. The authors propose a scheduling algorithm at the medium access control (MAC) layer for multiple connections with diverse QoS requirements, where each connection employs adaptive modulation and coding (AMC) scheme at the physical (PHY) layer over wireless fading channels. Each connection is assigned a priority, which is updated dynamically based on its channel and service status; the connection with the highest priority is scheduled each time. The authors' scheduler provides diverse QoS guarantees, uses the wireless bandwidth efficiently, and enjoys flexibility, scalability, and low implementation complexity. Its performance is evaluated via simulations. 相似文献
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A new approximation of fair queuing called Comensating Round Robin(CRR)ia presented in this paper.The algorithm uses packet-by-packet scheduler with a compensating measure.It achieves good fairness in terms of throrghput ,requires onlyO(1)time complexity to process a packet ,and is simple enough to be implemented in hardware.After the performances are analyzed ,the fairness and is simple enough to be implemented in hardware.After the performances are that the CRR can effectively isolate the effects of contending sources. 相似文献
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A scheduling algorithm for QoS support in IEEE802.11 networks 总被引:2,自引:0,他引:2
This article presents a scheduling algorithm for the IEEE 802.11e hybrid coordination function under definition by the IEEE 802.11e task group. HCF can be used to provide IP quality of service guarantees in IEEE802.11e infrastructure WLANs. The enhanced distributed coordination function is mainly used for data transmission without QoS guarantees, but can also be used to decrease the transmission delay of QoS-sensitive traffic. Scheduling of queued packets follows a delay-earliest-due-date algorithm. The proposed algorithm is compatible with the link adaptation mechanisms implemented in commercial WLANs, as it limits the amount of time during which the stations control the wireless medium. The performance of the algorithm is evaluated through computer simulation and compared with the reference scheduler presented by the IEEE 802.11e task group. 相似文献
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Tan Wei Zhang Zhizhong Luo Yunhan Wang Sheng Li Lemin 《电子科学学刊(英文版)》2006,23(5):656-660
A new scheduling algorithm, which aims to provide proportional and controllable QoS (Quality of Service) in terms of burst loss probability for OBS (Optical Burst Switching) networks, is proposed on the basis of a survey of QoS schemes in current OBS networks. With simulations, performance analysis and comparisons are carried out in detail. The results show that, in the proposed scheme, burst loss probabilities are proportional to the given factors and the control of QoS performance can be achieved with better performance. This scheme will be beneficial to the OBS network management and the tariffpolicy making. 相似文献
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适用于HFC网络的碰撞解决算法 总被引:5,自引:0,他引:5
回顾了HFC网络DOCSIS标准中采用的碰撞解决算法,通过计算机仿真比较了各种退避窗口设置的性能差异,在此基础上提出了基于负荷大小和FIFO首传规则的动态碰撞解决算法,并以仿真结果验证其性能,获得了较佳的性能参数。 相似文献
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DOCSIS协议已经成为HFC网络上传输IP数据事实上的全球标准,以DOCSIS协议为基础并充分考虑到用户的优先级水平,提出一种交互式视频点播(I-VOD)的实现原理,为VOD业务和宽带Ca-ble Modem业务的融合提供了一种思路。 相似文献
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HFC双向网络中CM宽带接入技术研究与实现 总被引:1,自引:0,他引:1
Cable Modem接入技术是当前实现"三网合一"和解决信息高速公路"最后1 km"高速宽带接入技术的最佳解决方案之一.详细介绍了当前HFC网络中Cable Modem接入技术的理论基础--DOCSIS协议标准,提出了交互式HFC双向网络中的Cable Modem接入技术解决方案,设计、制作并调试了以TMS320C5402,AD9853和AD8348为核心,符合ITU-T协议标准的全双工Cable Modem. 相似文献
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介绍S—CDMA技术的原理,简要比较在HFC网络中应用的3种多址技术,即频分多址FDMA、时分多址TDMA和码分多址CDMA,主要讨论应用于CATV网络的S—CDMA传输技术,并对其抗噪干扰性能进行分析。 相似文献