随着卫星通信技术的日益发展,系统内部多信道并存的现象越来越普遍,信道间传输的业务容易引起相互干扰,单纯运用传统路由器很难完成系统中不同信道间的业务完整隔离;同时,多信道卫星通信系统网络拓扑结构复杂,易引起控制混乱等问题。针...随着卫星通信技术的日益发展,系统内部多信道并存的现象越来越普遍,信道间传输的业务容易引起相互干扰,单纯运用传统路由器很难完成系统中不同信道间的业务完整隔离;同时,多信道卫星通信系统网络拓扑结构复杂,易引起控制混乱等问题。针对这些问题,提出一种基于虚拟局域网(Virtual Local Area Network,VLAN)的多信道卫星通信地面系统的设计方法。该方法充分利用网络划分VLAN技术的隔离性和安全性特征,结合多信道通信技术使用多个信道同时传输业务的特征,提升特征维度,实现高效、可靠的多信道卫星通信,具有易于硬件实现的特点,提高网络通信的吞吐量。展开更多
The use of Global Navigation Satellite Systems (GNSS) for positioning has revolutionized the way location data is be- ing collected. The NAVigation System with Time And Ranging Global Positioning System (GPS), which i...The use of Global Navigation Satellite Systems (GNSS) for positioning has revolutionized the way location data is be- ing collected. The NAVigation System with Time And Ranging Global Positioning System (GPS), which is a principal component of the global navigation satellite system (GNSS);is a satellite-based radio navigation system that provides positions of points of interest and time information to users. GPS positional accuracy can be improved by using differential corrections obtained through a technique called Differential GPS (DGPS), which is known to provide the most accurate positioning results. Differential correction can be applied in real time at the data collection phase or in the of- fice, at the post-processing phase. DGPS is generally used for positioning purposes through static or kinematics GPS surveys. In static GPS surveys, one receiver is placed at a point whose coordinates are known and the other receiver is placed over a point whose coordinates are desired. In kinematic surveys, one receiver remains at one point (base station) normally with known coordinates, and the other receiver (rover) moves from point to point in the project area. Kinematic surveys in which points positions are computed on-the-fly (OTF) are known as real-time kinematic (RTK). RTK surveys provide real-time locations of points of interest needed in many applications. Positioning with wide-area GNSS networks is basically based on the DGPS and RTK concepts. Observables from a network of a finite number of GPS receivers over an area are processed by a server at a central location (network server) and made available to the users of the network later or in real-time through radio-based, satellite, or wireless communications. This article provides a review of the concept and application of positioning with wide-area GNSS networks.展开更多
软件定义网络(Software Defined Netrork,SDN)技术在医院网络中的应用已经取得了显著进展,为医疗信息化和服务提供了强大的支持。讨论了传统医院网络架构所面临的多项挑战,包括内外网边界隔离、网络安全问题、业务复杂场景等,并探讨了SD...软件定义网络(Software Defined Netrork,SDN)技术在医院网络中的应用已经取得了显著进展,为医疗信息化和服务提供了强大的支持。讨论了传统医院网络架构所面临的多项挑战,包括内外网边界隔离、网络安全问题、业务复杂场景等,并探讨了SDN如何应对这些挑战以及如何改善医院网络的性能和安全性。具体而言,SDN技术通过多网融合,使用虚拟扩展局域网(Virtual Extensible Local Area Network,VXLAN)实现逻辑隔离,简化了网络配置和管理,同时确保了网络的安全性。除此以外,SDN引入了虚拟安全资源池和网络功能虚拟化(Network Functions Virtualization,NFV)技术,实现了跨网流量的安全访问和高效管理。SDN的网络智能和运维简化使医院能够更好地适应不同业务场景,提高了网络的灵活性和可管理性。总之,SDN技术在医院网络中的应用为医院信息化带来了新的可能性,同时提出了未来进一步改进和发展的方向。展开更多
文摘随着卫星通信技术的日益发展,系统内部多信道并存的现象越来越普遍,信道间传输的业务容易引起相互干扰,单纯运用传统路由器很难完成系统中不同信道间的业务完整隔离;同时,多信道卫星通信系统网络拓扑结构复杂,易引起控制混乱等问题。针对这些问题,提出一种基于虚拟局域网(Virtual Local Area Network,VLAN)的多信道卫星通信地面系统的设计方法。该方法充分利用网络划分VLAN技术的隔离性和安全性特征,结合多信道通信技术使用多个信道同时传输业务的特征,提升特征维度,实现高效、可靠的多信道卫星通信,具有易于硬件实现的特点,提高网络通信的吞吐量。
文摘The use of Global Navigation Satellite Systems (GNSS) for positioning has revolutionized the way location data is be- ing collected. The NAVigation System with Time And Ranging Global Positioning System (GPS), which is a principal component of the global navigation satellite system (GNSS);is a satellite-based radio navigation system that provides positions of points of interest and time information to users. GPS positional accuracy can be improved by using differential corrections obtained through a technique called Differential GPS (DGPS), which is known to provide the most accurate positioning results. Differential correction can be applied in real time at the data collection phase or in the of- fice, at the post-processing phase. DGPS is generally used for positioning purposes through static or kinematics GPS surveys. In static GPS surveys, one receiver is placed at a point whose coordinates are known and the other receiver is placed over a point whose coordinates are desired. In kinematic surveys, one receiver remains at one point (base station) normally with known coordinates, and the other receiver (rover) moves from point to point in the project area. Kinematic surveys in which points positions are computed on-the-fly (OTF) are known as real-time kinematic (RTK). RTK surveys provide real-time locations of points of interest needed in many applications. Positioning with wide-area GNSS networks is basically based on the DGPS and RTK concepts. Observables from a network of a finite number of GPS receivers over an area are processed by a server at a central location (network server) and made available to the users of the network later or in real-time through radio-based, satellite, or wireless communications. This article provides a review of the concept and application of positioning with wide-area GNSS networks.
文摘软件定义网络(Software Defined Netrork,SDN)技术在医院网络中的应用已经取得了显著进展,为医疗信息化和服务提供了强大的支持。讨论了传统医院网络架构所面临的多项挑战,包括内外网边界隔离、网络安全问题、业务复杂场景等,并探讨了SDN如何应对这些挑战以及如何改善医院网络的性能和安全性。具体而言,SDN技术通过多网融合,使用虚拟扩展局域网(Virtual Extensible Local Area Network,VXLAN)实现逻辑隔离,简化了网络配置和管理,同时确保了网络的安全性。除此以外,SDN引入了虚拟安全资源池和网络功能虚拟化(Network Functions Virtualization,NFV)技术,实现了跨网流量的安全访问和高效管理。SDN的网络智能和运维简化使医院能够更好地适应不同业务场景,提高了网络的灵活性和可管理性。总之,SDN技术在医院网络中的应用为医院信息化带来了新的可能性,同时提出了未来进一步改进和发展的方向。
