Desert Storm: air assault communications

The development of the US Army's 101st Airborne Division (Air Assault) Signal Battalion's command and control communications system from base-camp communications system into a system that provided division offensive communications which spanned more than 1000 miles and supported air assault ground and air combat offense operations in Iraq during Operations Desert Shield and Desert Storm is discussed. The forward operating base used the AN/TRC-170 multichannel tropospheric scatter communication system as the backbone and multichannel tactical satellite communication as the pivotal means for follow-on movement. The systems deployed by the battalion for base camp communications, covering force communications, and offensive communications are described     

Tactical military communications

The evolution of Army tactical communications systems, starting with the formation of the Signal Corps in 1856, is outlined. The use of mobile subscriber equipment (MSE), the single channel ground and airborne radio system (SINCGARS), and the maneuver control system (MCS), among others, to support American troops in Operation Desert Storm is described, and a representative sample of signal unit employment is presented. The fundamental goals of near-term efforts at the Army Signal Center to complete the planned Army tactical command and control (ATCCS) architecture, to enhance the integration of the systems composing that architecture, to prepare for and maintain compatibility with developments in the strategic environment, sustaining base, and tactical user community are discussed     

US Air Force communications in Desert Storm

The US Central Command Air Forces' (USCENTAF) communications network for Operations Desert Shield and Desert Storm is described. The Central Command Air Forces network utilized 27 SatCom terminals, 27 automatic switches, and 27 terrestrial links and had the responsibility of providing air traffic services across six countries at 24 locations handling 350000 flight operations. The system complexity and air traffic operations, satellite transmission system, terrestrial transmission system, and voice switched network are discussed     

The point of the spear [command and control communication system]

The command and control communication system that supported the 24th Infantry Division (Mechanized) during their charge into Iraq in Operation Desert Storm is discussed. The three primary types of communications used were the tactical telephone network, single channel radios, and hard copy or message traffic. Background on the communication systems is presented, and planning for the operation and deployment of the command and control communication system, including command post configurations, are described     

CAPS地面站天线跟踪卫星

地面站是卫星导航通信系统中必不可少的重要组成部分,具备接收、发射信号,监控卫星以及与地面通信网络通信交换等功能,地面站的大天线对星跟踪是卫星通信开展的基础。针对卫星地面站的重要性,介绍了CAPS(中国区域定位系统)位于北京的卫星通信地面站天线对星跟踪系统,利用该天线对准亚太I号卫星时的方位角、俯仰角以及系统AGC电平值分析了亚太I号卫星的运动轨迹,亚太I号卫星的漂移幅度在不断的增大。     

The rapid deployment digital satellite network

The ground mobile forces (GMF) satellite digital multichannel radio, which provided the US Marine Corps with the primary transmission links for its switched backbone during Operations Desert Shield and Desert Storm, is discussed. Reliable and highly mobile, the multichannel terminals provided clear and consistent digital pipelines for the Marine Corps circuit switched network and were rapidly deployed on military HWMMV vehicles. The GMF multichannel radios use the defense satellite communication system (DSCS) II and III super-high-frequency (SHF) wideband satellites as retransmission platforms enabling them to be operated theater-wide with no limit on transmission link distance. The deployment and installation of GMF assets in support of the 1st Marine Expeditionary Force during Desert Shield/Desert Storm, including the minimization of outage time due to Sun passage through the radio beam, are described     

SATELLITE-ENHANCED PERSONAL COMMUNICATIONS EXPERIMENTS

Users of future generation wireless information services will have diverse needs for voice, data, and potentially even video communications in a wide variety of circumstances. For users in dense, inner-city areas, low power personal communications services (PCS) technology should be ideal. Vehicular-based users travelling at high speeds will need high-power cellular technology. For users in remote or inaccessible locations, or for applications that are broadcast over a wide geographic area, a satellite technology would be the best choice. Packet data networks provide an excellent solution for users requiring occasional small messages, whereas circuit switched networks provide more economical solutions for larger messages. To provide ubiquitous personal communications service, it is necessary to capitalize on the strength of each wireless technology and network to create one seamless internetwork including both current and future wired and wireless networks. As an initial step in exploring the opportunities afforded by the merging of satellite and terrestrial networks, Bellcore and JPL conducted several experiments. These experiments utilized Bellcore's experimental personal communications system (including several messaging applications with adaptations to wireless networks), NASA's advanced communications technology satellite (ACTS), JPL's ACTS mobile terminal, and various commercial data networks (such as the wireline Internet and the RAM wireless packet data network). Looking at loss of bits, packets and higher layer blocks (over the satellite-terrestrial internetworks with mobile and stationary users under various conditions) our initial results indicate that the communication channel can vary dramatically, even within a single network. We show that these conditions necessitate powerful and adaptive protocols if we are to achieve a seamless internetworking of satellite and terrestrial networks.     

A new satellite communication system integrated into publicswitched networks-DYANET

A system concept of a common alternative routing system is proposed for reducing total network costs by integrating satellite communications into public-switched networks, where satellite systems carry overflow traffic from terrestrial systems through common satellite channels. This concept has been realized by a satellite communication system called DYANET (dynamic channel assigning and routing satellite aided digital networks), which provides trunk circuits in combination with terrestrial systems. The key technologies developed for DYANET are a centralized network control system and a transponder hopping demand assignment TDMA (time-division multiple-access) system, to assure single-hop connection and to use satellite channel efficiently. The authors describe the system concept and configuration, the network control system, and the results of its commercial use     

An introduction to I2C and SPI protocols

Today, at the low end of the communication protocols we fi nd the inter-integrated circuit (I2C) and the serial peripheral interface (SPI) protocols. Both protocols are well suited for communications between integrated circuits for slow communication with on-board peripherals. The two protocols coexist in modern digital electronics systems, and they probably will continue to compete in the future, as both I2C and SPI are actually quite complementary for this kind of communication.     

Miniaturized reverse modulation loop of a CQPSK 120 Mbit/s modemfor spacecraft applications

The design and performance of a miniaturized reverse modulation loop (RML) for a 120 Mbit/s coherent quadrature phase shift keying (CQPSK) modem for onboard satellite applications are presented. Analysis of time delays within the RML circuit indicates that any differential time-delay errors can adversely affect the associated BER and should be minimized. The RML circuit, consisting of a modulator, demodulator, and comparator circuit, has been fabricated using quasi-monolithic techniques with dimensions of 1.65×4 cm. The relative phase for all four states of the modulator is in close agreement with design values of 90°±1° over a 200 MHz bandwidth at 3.95 GHz. The demodulator and comparator circuits of the RML have successfully recovered a 120 Mbit/s bit stream. The RML circuit is capable of recovering higher bit rates because of relatively uniform amplitude and phase performance over the 3.7- to 4.2 GHz communications satellite band     

标校卫星地面应用系统方案设计

卫星标校技术采用低轨卫星搭载标校载荷为地面测控设备标定系统误差,由于国内标校卫星发展较晚,相关研究主要集中于地面具体型号测控设备的卫星标校方法,缺少标校卫星地面系统研究以及真实卫星数据和试验验证手段。针对国内首个标校卫星型号“天平”一号卫星地面应用系统,设计了系统工作模式,提出了标校卫星任务规划方法,并对精密定轨调度和标校数据处理业务流程进行了分析设计。标校卫星地面应用系统面向标校用户提供测控设备标校服务,并为后续研究提供真实卫星数据和试验验证平台。     

Redundancy design for the Vela spacecraft

Various redundancy tradeoffs with respect to weight, power, reliability, and testing ability are discussed for the Vela spacecraft. The types of redundancy considered were complete circuit (such as quads), standby automatic switchable, standby command switchable, and fully automatic. Complete circuit redundancy was rejected because of weight and power limitations. Standby automatic switchable redundancy was rejected because of possible failure modes and complexity of the automatic detection circuits. Fully automatic redundancy was applied to those portions of the system where a failure would cause loss of the mission. Standby command switchable redundancy was applied to those portions of the system where a failure could be detected and corrected by command switching. The final redundant system is compared with a nonredundant system to indicate the additional weight and power required to accomplish the redundancy design.     

Mobility management protocols for next-generation all-IP satellite networks [architectures and protocols for mobility management in all-IP mobile networks]

To provide ubiquitous terrestrial Internet coverage mobility and Internet-based access to data generated by satellites, there is a strong desire to integrate the terrestrial Internet and satellite networks. This requires satellites that are based on IP for communications. Rotation of low Earth orbit satellites around the Earth results in communicating with different ground stations over time, and requires mobility management protocols for seamless communication between the Internet and satellite networks. In this article we provide a comprehensive summary and comparison of state-of-the-art research on mobility management schemes for satellite networks. The schemes are based on network and transport layers for managing host and network mobility. This article clearly indicates the aspects that need further research and which mobility management schemes are the best candidates for satellite networks.     

A satellite data transmission antenna

A retrodirective satellite antenna for a broad bandwidth, satellite-to-ground data transmission link, is described. An information-collecting satellite which transmits its data in the direction of the ground receiver upon command, is considered. The satellite antenna described for this system is an active retrodirective antenna which utilizes the beam-forming characteristics of a phasing matrix. A signal from the ground station is received on a particular beam port of the matrix which corresponds to a particular beam-pointing direction. Control circuitry in the satellite activates a switching matrix and a transmitter so that the data-carrying signal is transmitted in the same direction from which the satellite is interrogated. Other retrodirective techniques in addition to the phasing-matrix antenna are evaluated in terms of their relative merit. The systems considered include the active Van Atta array, the automatic three-dimensional electronic scanning, antenna (ATHESA), the Luneberg lens and various other antenna array techniques.     

Commercial satellite communications experience

The operational Intelsat I (Early Bird) and Intelsat II satellites and associated earth stations that comprise the present commercial satellite communications system provide a capacity of close to 720 voice circuits between major earth stations. All but a limited portion of the inhabited globe is now within the line of sight of a commercial satellite relay. In addition, it is expected that by 1968, with the operation of Intelsat III, a truly global international satellite communications system will exist.     

A model for the handover traffic in low earth-orbiting (LEO) satellite networks for personal communications

The spectacular growth of cellular telephone networks has demonstrated the demand for personal communications. Communication systems based on low earth orbit (LEO) constellations of satellites seem to be an adequate approach to achieve a world-wide network. When defining the capacity in terms of satellite circuits, the network designer has to take into account the handover traffic. Unfortunately, in a LEO communication network where handover is most often due to the network nodes motion, handover traffic models for terrestrial cellular networks cannot be used. Hence specific models must be developed. This paper proposes an analytical model for the handover in LEO satellite networks. This model is applied to different network configurations and compared to discrete-time simulations. Simulation results agree with those obtained from the analytical model.     

The role of satellite communication in the ISDN era

Satellite communications can play an important role in provisioning the next-generation telecommunications services and networks, provided that the protocols specifying these services and networks are satellite-compatible. After a brief discussion of narrowband circuit and packet mode integrated service digital network (ISDN) services, the paper focuses on emerging standards in frame relay, broadband ISDN (BISDN) and universal personal telecommunications (UPT). The specific parameters and procedures of frame relay and BISDN protocols which are affected by a satellite delay are identified, and congestion and resource management functions for frame relay and BISDN are discussed in detail. Specific ground functions and possible on-board functions are identified as potential candidates for implementation via neural network technology. Finally, the implication of UPT standards on satellite networks is discussed.     

Next generation satellite systems for aeronautical communications

U.S. airspace is reaching its capacity with the current air traffic control (ATC) system. The number of flights is constantly rising and it is estimated to be over 58 million per year by 2005. The FAA has undertaken several projects to modernize the National Airspace System (NAS) to ensure the safety of the increasing number of flights. Of special importance is the modernization of the air–ground communications infrastructure, which is the heart of the ATC. The current plan in the modernization of the air–ground communications is to migrate from analog voice only system to integrated digital voice and data system. The next generation satellite systems can be an alternative to the terrestrial air–ground systems by their low propagation and transmission delays, global coverage, high capacity and free flight suitable characteristics. In this paper, we give an overview of the current and the future ATC architectures, describe the systems and the communications issues in these systems and develop a framework in which next generation satellite systems can be integrated to the future ATC systems. Copyright © 2004 John Wiley & Sons, Ltd.     

面向6G的卫星通信网络架构展望

分析和研究了未来6G卫星网络架构并提出了设想。首先介绍国内外星地融合的研究现状,结合6G网络的愿景、需求和6G网络架构的当前研究成果,总结了6G网络架构的技术特征;然后通过对人工智能（AI）在通信领域的研究和应用分析,以及AI在6G网络中关键作用的深入挖掘,提出了AI赋能的6G卫星通信网络总体架构、接入网架构及核心网架构的设想,同时提出了分阶段演进和分步骤实现的建设思路,最后对基于区块链的6G卫星通信网络韧性鲁棒机制进行了技术探讨。     

低轨卫星与5G-R融合网络架构设计

由于地面网络覆盖不均匀,信号质量不够稳定,无法实现铁路交通网络的全程、快速、实时监测,阻碍了我国铁路交通网络的快速发展。同时,低轨卫星通信与地面5G的融合成为热点,二者的融合能够使卫星网络作为地面网络的有效补充。当前星地融合较少用于5G-R技术场景中。本文梳理了铁路卫星通信以及星地融合网络的研究现状与发展趋势;分析了铁路通信系统中各业务的通信需求。在此基础上,提出低轨卫星与5G-R融合网络架构。在弥补铁路通信网络覆盖盲区的同时,提供大容量的信息回传,有效保障铁路交通的安全运行,实现铁路交通的信息化、智能化管理。