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
分组数据汇聚协议(packet data convergence protocol,PDCP)层在LTE协议栈中实现对数据的加密、完整性保护、头压缩等功能。为了实现PDCP层在协议栈中的整体功能,分析了PDCP层总体功能流程、数据单元结构,重点研究了无线承载映射到无线...分组数据汇聚协议(packet data convergence protocol,PDCP)层在LTE协议栈中实现对数据的加密、完整性保护、头压缩等功能。为了实现PDCP层在协议栈中的整体功能,分析了PDCP层总体功能流程、数据单元结构,重点研究了无线承载映射到无线链路控制(radio link control,RLC)确认模式下的数据接收机制、连接重建中PDCP的重建处理和状态报告的使用,设计出PDCP层相关的消息序列图。通过分析发现,上述新机制既能保证数据在PD-CP中按序处理,又能避免数据的丢失和重复收发。展开更多
5G引入分组数据汇聚协议复制(packet data convergence protocol duplication,PD)功能以解决超可靠低时延通信应用场景的通信需求。为实现PD功能,设计基于5G双连接架构的PD协议栈架构、动态控制PD激活与去激活机制和应用PD的切换过程。...5G引入分组数据汇聚协议复制(packet data convergence protocol duplication,PD)功能以解决超可靠低时延通信应用场景的通信需求。为实现PD功能,设计基于5G双连接架构的PD协议栈架构、动态控制PD激活与去激活机制和应用PD的切换过程。通过建立PD的性能评估模型,仿真分析结果表明,在小区边缘,PD在满足可靠性和时延要求的同时比单链路减少30%的无线资源占用,在用户设备移动过程中,PD满足高可靠低时延需求并提高了2%的无线资源利用率。PD能够在不增加无线接入网复杂性的情况下,同时满足1-10-5的可靠性和1ms的时延需求。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.
文摘分组数据汇聚协议(packet data convergence protocol,PDCP)层在LTE协议栈中实现对数据的加密、完整性保护、头压缩等功能。为了实现PDCP层在协议栈中的整体功能,分析了PDCP层总体功能流程、数据单元结构,重点研究了无线承载映射到无线链路控制(radio link control,RLC)确认模式下的数据接收机制、连接重建中PDCP的重建处理和状态报告的使用,设计出PDCP层相关的消息序列图。通过分析发现,上述新机制既能保证数据在PD-CP中按序处理,又能避免数据的丢失和重复收发。
文摘5G引入分组数据汇聚协议复制(packet data convergence protocol duplication,PD)功能以解决超可靠低时延通信应用场景的通信需求。为实现PD功能,设计基于5G双连接架构的PD协议栈架构、动态控制PD激活与去激活机制和应用PD的切换过程。通过建立PD的性能评估模型,仿真分析结果表明,在小区边缘,PD在满足可靠性和时延要求的同时比单链路减少30%的无线资源占用,在用户设备移动过程中,PD满足高可靠低时延需求并提高了2%的无线资源利用率。PD能够在不增加无线接入网复杂性的情况下,同时满足1-10-5的可靠性和1ms的时延需求。
