This research paper describes the design and implementation of the Consultative Committee for Space Data Systems (CCSDS) standards REF _Ref401069962 \r \h \* MERGEFORMAT [1] for Space Data Link Layer Protocol (SDLP). ...This research paper describes the design and implementation of the Consultative Committee for Space Data Systems (CCSDS) standards REF _Ref401069962 \r \h \* MERGEFORMAT [1] for Space Data Link Layer Protocol (SDLP). The primer focus is the telecommand (TC) part of the standard. The implementation of the standard was in the form of DLL functions using C++ programming language. The second objective of this paper was to use the DLL functions with OMNeT++ simulating environment to create a simulator in order to analyze the mean end-to-end Packet Delay, maximum achievable application layer throughput for a given fixed link capacity and normalized protocol overhead, defined as the total number of bytes transmitted on the link in a given period of time (e.g. per second) divided by the number of bytes of application data received at the application layer model data sink. In addition, the DLL was also integrated with Ground Support Equipment Operating System (GSEOS), a software system for space instruments and small spacecrafts especially suited for low budget missions. The SDLP is designed for rapid test system design and high flexibility for changing telemetry and command requirements. GSEOS can be seamlessly moved from EM/FM development (bench testing) to flight operations. It features the Python programming language as a configuration/scripting tool and can easily be extended to accommodate custom hardware interfaces. This paper also shows the results of the simulations and its analysis.展开更多
针对星地、星间复杂空间链路之间的高效数据传输需求,融合国际空间数据系统咨询委员会(Consultative Committee for Space Date System, CCSDS)与传输控制协议(Transmission Control Protocol, TCP)/互联网协议(Internet Protocol, IP)...针对星地、星间复杂空间链路之间的高效数据传输需求,融合国际空间数据系统咨询委员会(Consultative Committee for Space Date System, CCSDS)与传输控制协议(Transmission Control Protocol, TCP)/互联网协议(Internet Protocol, IP),基于物理层、数据链路层、网络层、传输层、应用层协议模型,提出了空间链路统一传输协议总体设计方案。针对不同空间链路协议差异导致的数据交互复杂问题,数据链路层采用统一空间数据链路协议,实现异构空间链路多业务混合传输;网络层采用封装数据包和IPoC(IP over CCSDS)协议承载IP数据,便于统一寻址;应用层采用空间数据包协议。通过数据链路层传输帧信道复用、网络层IP数据包复用与聚合、应用层空间数据包聚合,在不同通信协议层面实现了不同应用数据的融合传输。在地面测试系统中模拟星地、星间通信场景,验证了所提出的空间链路网络协议格式和数据传输服务的有效性。展开更多
In this paper, we present a stochastic model for data in a Wireless Sensor Network (WSN) using random field theory. The model captures the space-time behavior of the underlying phenomenon being observed by the network...In this paper, we present a stochastic model for data in a Wireless Sensor Network (WSN) using random field theory. The model captures the space-time behavior of the underlying phenomenon being observed by the network. We present results regarding the size and spatial distribution of the regions of the network that sense statistically extreme values of the underlying phenomenon using the theory of extreme excursion regions. These results compliment many existing works in the literature that describe algorithms to reduce the data load, but lack an analytical approach to evaluate the size and spatial distribution of this load. We show that if only the statistically extreme data is transmitted in the network, then the data load can be significantly reduced. Finally, a simple performance model of a WSN is developed based on a collection of asynchronous M/M/1 servers that work in parallel. We derive several performance measures from this performance model. The presented results will be useful in the design of large scale sensor networks.展开更多
针对航天测控领域中上行遥控业务的协议体系选择与可靠性设计问题,在对我国现行国军标技术指标要求与现有航天测控系统天地基遥控技术特点进行归纳梳理的基础上,基于空间段信息传输无线链路特点与CCSDS(Consultative Committee for Spac...针对航天测控领域中上行遥控业务的协议体系选择与可靠性设计问题,在对我国现行国军标技术指标要求与现有航天测控系统天地基遥控技术特点进行归纳梳理的基础上,基于空间段信息传输无线链路特点与CCSDS(Consultative Committee for Space Data Systems,空间数据系统咨询委员会)标准规范,研究给出了适用于我国航天测控任务的空间段遥控协议体系与可靠性措施,利用梳理统计方法对上行遥控体制进行了数学建模分析,并与CCSDS给出的应用算例进行了对比分析。分析结果表明,所涉及的上行遥控体制与CCSDS标准规范的工作效能基本相当,能够满足我国航天任务上行遥控任务使用需求。展开更多
文摘This research paper describes the design and implementation of the Consultative Committee for Space Data Systems (CCSDS) standards REF _Ref401069962 \r \h \* MERGEFORMAT [1] for Space Data Link Layer Protocol (SDLP). The primer focus is the telecommand (TC) part of the standard. The implementation of the standard was in the form of DLL functions using C++ programming language. The second objective of this paper was to use the DLL functions with OMNeT++ simulating environment to create a simulator in order to analyze the mean end-to-end Packet Delay, maximum achievable application layer throughput for a given fixed link capacity and normalized protocol overhead, defined as the total number of bytes transmitted on the link in a given period of time (e.g. per second) divided by the number of bytes of application data received at the application layer model data sink. In addition, the DLL was also integrated with Ground Support Equipment Operating System (GSEOS), a software system for space instruments and small spacecrafts especially suited for low budget missions. The SDLP is designed for rapid test system design and high flexibility for changing telemetry and command requirements. GSEOS can be seamlessly moved from EM/FM development (bench testing) to flight operations. It features the Python programming language as a configuration/scripting tool and can easily be extended to accommodate custom hardware interfaces. This paper also shows the results of the simulations and its analysis.
文摘针对星地、星间复杂空间链路之间的高效数据传输需求,融合国际空间数据系统咨询委员会(Consultative Committee for Space Date System, CCSDS)与传输控制协议(Transmission Control Protocol, TCP)/互联网协议(Internet Protocol, IP),基于物理层、数据链路层、网络层、传输层、应用层协议模型,提出了空间链路统一传输协议总体设计方案。针对不同空间链路协议差异导致的数据交互复杂问题,数据链路层采用统一空间数据链路协议,实现异构空间链路多业务混合传输;网络层采用封装数据包和IPoC(IP over CCSDS)协议承载IP数据,便于统一寻址;应用层采用空间数据包协议。通过数据链路层传输帧信道复用、网络层IP数据包复用与聚合、应用层空间数据包聚合,在不同通信协议层面实现了不同应用数据的融合传输。在地面测试系统中模拟星地、星间通信场景,验证了所提出的空间链路网络协议格式和数据传输服务的有效性。
文摘In this paper, we present a stochastic model for data in a Wireless Sensor Network (WSN) using random field theory. The model captures the space-time behavior of the underlying phenomenon being observed by the network. We present results regarding the size and spatial distribution of the regions of the network that sense statistically extreme values of the underlying phenomenon using the theory of extreme excursion regions. These results compliment many existing works in the literature that describe algorithms to reduce the data load, but lack an analytical approach to evaluate the size and spatial distribution of this load. We show that if only the statistically extreme data is transmitted in the network, then the data load can be significantly reduced. Finally, a simple performance model of a WSN is developed based on a collection of asynchronous M/M/1 servers that work in parallel. We derive several performance measures from this performance model. The presented results will be useful in the design of large scale sensor networks.
文摘针对航天测控领域中上行遥控业务的协议体系选择与可靠性设计问题,在对我国现行国军标技术指标要求与现有航天测控系统天地基遥控技术特点进行归纳梳理的基础上,基于空间段信息传输无线链路特点与CCSDS(Consultative Committee for Space Data Systems,空间数据系统咨询委员会)标准规范,研究给出了适用于我国航天测控任务的空间段遥控协议体系与可靠性措施,利用梳理统计方法对上行遥控体制进行了数学建模分析,并与CCSDS给出的应用算例进行了对比分析。分析结果表明,所涉及的上行遥控体制与CCSDS标准规范的工作效能基本相当,能够满足我国航天任务上行遥控任务使用需求。
