The dynamic characteristics of eplicit control protocol (XCP) were investigated with single bottleneck on the microscopic time-scale. Analysis and simulation results show that the bandwidth utilization of an XCP bottl...The dynamic characteristics of eplicit control protocol (XCP) were investigated with single bottleneck on the microscopic time-scale. Analysis and simulation results show that the bandwidth utilization of an XCP bottleneck link converges to 1 at exponential rate, persistent congestion cannot occur at the bottleneck link, and throughput of an arbitrary subset of XCP flows at the bottleneck link converges to its fair share in exponential rate. The XCP has high bandwidth utilization and good fairness properties.展开更多
阐述五轴机床的RTCP(Real-time Transport Control Protocol)和非RTCP功能原理,研究双转台五轴机床的编程及加工机制。通过实验研究五轴RTCP及非RTCP后处理关键参数定制方法,使用NX后处理构造器建立后处理程序。利用Ver⁃icut平台进行零...阐述五轴机床的RTCP(Real-time Transport Control Protocol)和非RTCP功能原理,研究双转台五轴机床的编程及加工机制。通过实验研究五轴RTCP及非RTCP后处理关键参数定制方法,使用NX后处理构造器建立后处理程序。利用Ver⁃icut平台进行零件仿真加工,分析和比较加工结果,验证所提出的后处理器的正确性。研究结果为相关从业人员提供参考。展开更多
This paper chiefly introduces the model of Video Conferencing System, H.323 standard of ITU- T and RTP/RTCP protocol, and realizes a WAN- Oriented Video Conferencing System—VCSW (Video Conferencing System on WAN). In...This paper chiefly introduces the model of Video Conferencing System, H.323 standard of ITU- T and RTP/RTCP protocol, and realizes a WAN- Oriented Video Conferencing System—VCSW (Video Conferencing System on WAN). In VCSW, RTP/RTCP pro- tocol is used for transporting media data and video conference on WAN can be established, so VCSW has abroad application scope. This paper stresses analyzing RTP/RTCP protocol, realizes it and modifies some details of it according to our device condition: re- duces some fields of RTP and RTCP header, removes some information managed by RTP/RTCP. Consequently in testing of lab, good effect is achieved.展开更多
Distributed underwater acoustic sensor networks(UASNs)are envisioned in real-time ocean current velocity estimation.However,UASNs at present are still dominated by post-processing partially due to the complexity of on...Distributed underwater acoustic sensor networks(UASNs)are envisioned in real-time ocean current velocity estimation.However,UASNs at present are still dominated by post-processing partially due to the complexity of on-line detection for travel times and lack of dedicated medium access control(MAC)protocols.In this study,we propose a dedicated MAC protocol package for real-time ocean current velocity estimation using distributed UASNs.First,we introduce the process and requirements of ocean current velocity estimation.Then,we present a series of spatial reuse time division multiple access(TDMA)protocols for each phase of real-time ocean current field estimation using distributed UASNs,followed by numerical analysis.We divide UASNs into two categories according to their computing ability:feature-complete and feature-incomplete systems.The feature-complete systems that have abundant computing ability carry out the presented MAC protocol package in three phases,whereas the feature-incomplete ones do not have enough computing ability and the presented MAC protocol package is reduced to two phases plus an additional downloading phase.Numerical analysis shows that feature-complete systems using mini-slot TDMA have the best real-time performance,in comparison with feature-incomplete systems and other feature-complete counterparts.Feature-incomplete systems are more energy-saving than feature-complete ones,owing to the absence of in-network data exchange.展开更多
基金The National Natural Science Foundation of China (No. 60503049)
文摘The dynamic characteristics of eplicit control protocol (XCP) were investigated with single bottleneck on the microscopic time-scale. Analysis and simulation results show that the bandwidth utilization of an XCP bottleneck link converges to 1 at exponential rate, persistent congestion cannot occur at the bottleneck link, and throughput of an arbitrary subset of XCP flows at the bottleneck link converges to its fair share in exponential rate. The XCP has high bandwidth utilization and good fairness properties.
文摘阐述五轴机床的RTCP(Real-time Transport Control Protocol)和非RTCP功能原理,研究双转台五轴机床的编程及加工机制。通过实验研究五轴RTCP及非RTCP后处理关键参数定制方法,使用NX后处理构造器建立后处理程序。利用Ver⁃icut平台进行零件仿真加工,分析和比较加工结果,验证所提出的后处理器的正确性。研究结果为相关从业人员提供参考。
基金Approval No. of the National Natural ScienceFund: 60573182
文摘This paper chiefly introduces the model of Video Conferencing System, H.323 standard of ITU- T and RTP/RTCP protocol, and realizes a WAN- Oriented Video Conferencing System—VCSW (Video Conferencing System on WAN). In VCSW, RTP/RTCP pro- tocol is used for transporting media data and video conference on WAN can be established, so VCSW has abroad application scope. This paper stresses analyzing RTP/RTCP protocol, realizes it and modifies some details of it according to our device condition: re- duces some fields of RTP and RTCP header, removes some information managed by RTP/RTCP. Consequently in testing of lab, good effect is achieved.
基金This work was supported by the National Natural Science Foundation of China(No.61531017)the Science and Technology Bureau of Zhoushan(No.2018C41029)the Science and Technology Department of Zhejiang Province(Nos.2018R52046 and LGG18F010005).
文摘Distributed underwater acoustic sensor networks(UASNs)are envisioned in real-time ocean current velocity estimation.However,UASNs at present are still dominated by post-processing partially due to the complexity of on-line detection for travel times and lack of dedicated medium access control(MAC)protocols.In this study,we propose a dedicated MAC protocol package for real-time ocean current velocity estimation using distributed UASNs.First,we introduce the process and requirements of ocean current velocity estimation.Then,we present a series of spatial reuse time division multiple access(TDMA)protocols for each phase of real-time ocean current field estimation using distributed UASNs,followed by numerical analysis.We divide UASNs into two categories according to their computing ability:feature-complete and feature-incomplete systems.The feature-complete systems that have abundant computing ability carry out the presented MAC protocol package in three phases,whereas the feature-incomplete ones do not have enough computing ability and the presented MAC protocol package is reduced to two phases plus an additional downloading phase.Numerical analysis shows that feature-complete systems using mini-slot TDMA have the best real-time performance,in comparison with feature-incomplete systems and other feature-complete counterparts.Feature-incomplete systems are more energy-saving than feature-complete ones,owing to the absence of in-network data exchange.
