1、引言现代化浪潮席卷各个领域,以计算机通讯控制为基础的应用系统成为工业生产中的主力军。Windows 操作系统及可视化编程语言工具的出现,使得开发通讯类应用系统的上位机软件的过程,变得相对简单且系统功能强大。本文以8路 COM 端口...1、引言现代化浪潮席卷各个领域,以计算机通讯控制为基础的应用系统成为工业生产中的主力军。Windows 操作系统及可视化编程语言工具的出现,使得开发通讯类应用系统的上位机软件的过程,变得相对简单且系统功能强大。本文以8路 COM 端口通讯为例,探讨了VB6.0中的工业用多路通讯的机理;并将本人据此实现且实际应用的上位机程序作为贯穿全文的说明材料予以论述。2、问题描述系统采用'一对多(8)展开更多
Today's Internet architecture provides only "best effort" services,thus it cannot guarantee quality of service(QoS) for applications.Software Defined Network(SDN)is a new approach to computer networking ...Today's Internet architecture provides only "best effort" services,thus it cannot guarantee quality of service(QoS) for applications.Software Defined Network(SDN)is a new approach to computer networking that separates control plane and forwarding planes,and has the advantage of centralized control and programmability.In this paper,we propose HiQoS that provides QoS guarantees using SDN.Moreover,HiQoS makes use of multiple paths between source and destination and queuing mechanisms to guarantee QoS for different types of traffic.Experimental results show that our HiQoS scheme can reduce delay and increase throughput to guarantee QoS.Very importantly,HiQoS recovers from link failure very quickly by rerouting traffic from failed path to other available path.展开更多
A distributed QoS (quality of service) -aware source-specific multicast routing protocol—DQSSMR is proposed to increase the successful join ratio and lower the overhead of the control message in QoS required multicas...A distributed QoS (quality of service) -aware source-specific multicast routing protocol—DQSSMR is proposed to increase the successful join ratio and lower the overhead of the control message in QoS required multicast routing. By an improved searching strategy, the cost of message control is reduced and the successful join ratio is increased. The network load is balanced due to the distributed routing operation and the scalability is enhanced further because of the usage of SSM (source- specific multicast) service model in DQSSMR. The analysis results indicate that DQSSMR performs as expected.展开更多
It is necessary for an MC-CDMA uplink receiver to employ MUD (multiuser detection) in a frequency selective fading channel. After analyzing the algorithm of PIC(parallel interference cancellation) MUD, a novel MUD sch...It is necessary for an MC-CDMA uplink receiver to employ MUD (multiuser detection) in a frequency selective fading channel. After analyzing the algorithm of PIC(parallel interference cancellation) MUD, a novel MUD scheme, Soft-PIC (soft parallel interference cancellation) is proposed. Based on the reliability of each detected user signal in the former stage, this Soft-PIC detection scheme substitutes a soft decision of the variable for the hard decision in PIC scheme. Compared with the PIC scheme, it can reconstruct the interference signals more accurately and eliminate MAI(multiple access interference) in a more efficient way.PIC is one of the most practical schemes in numerous multiuser detection technologies. However, Soft-PIC as an improved PIC scheme deserves further study.展开更多
文摘1、引言现代化浪潮席卷各个领域,以计算机通讯控制为基础的应用系统成为工业生产中的主力军。Windows 操作系统及可视化编程语言工具的出现,使得开发通讯类应用系统的上位机软件的过程,变得相对简单且系统功能强大。本文以8路 COM 端口通讯为例,探讨了VB6.0中的工业用多路通讯的机理;并将本人据此实现且实际应用的上位机程序作为贯穿全文的说明材料予以论述。2、问题描述系统采用'一对多(8)
基金supported partly by NSFC(National Natural Science Foundation of China)under grant No.61371191 and No.61472389
文摘Today's Internet architecture provides only "best effort" services,thus it cannot guarantee quality of service(QoS) for applications.Software Defined Network(SDN)is a new approach to computer networking that separates control plane and forwarding planes,and has the advantage of centralized control and programmability.In this paper,we propose HiQoS that provides QoS guarantees using SDN.Moreover,HiQoS makes use of multiple paths between source and destination and queuing mechanisms to guarantee QoS for different types of traffic.Experimental results show that our HiQoS scheme can reduce delay and increase throughput to guarantee QoS.Very importantly,HiQoS recovers from link failure very quickly by rerouting traffic from failed path to other available path.
文摘A distributed QoS (quality of service) -aware source-specific multicast routing protocol—DQSSMR is proposed to increase the successful join ratio and lower the overhead of the control message in QoS required multicast routing. By an improved searching strategy, the cost of message control is reduced and the successful join ratio is increased. The network load is balanced due to the distributed routing operation and the scalability is enhanced further because of the usage of SSM (source- specific multicast) service model in DQSSMR. The analysis results indicate that DQSSMR performs as expected.
文摘It is necessary for an MC-CDMA uplink receiver to employ MUD (multiuser detection) in a frequency selective fading channel. After analyzing the algorithm of PIC(parallel interference cancellation) MUD, a novel MUD scheme, Soft-PIC (soft parallel interference cancellation) is proposed. Based on the reliability of each detected user signal in the former stage, this Soft-PIC detection scheme substitutes a soft decision of the variable for the hard decision in PIC scheme. Compared with the PIC scheme, it can reconstruct the interference signals more accurately and eliminate MAI(multiple access interference) in a more efficient way.PIC is one of the most practical schemes in numerous multiuser detection technologies. However, Soft-PIC as an improved PIC scheme deserves further study.
