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2003
A fully articulated shipboard satellite antenna system operating at Ka-band (30/20 GHz) was designed, developed, and tested by engineers from the Naval Research Laboratory (NRL), NASA's Glenn Research Center, and a number of industry partners. A series of tests conducted in October of 1998 on Lake Michigan (in the Chicago area), using NASA's Advanced Communications Technology Satellite (ACTS), achieved an unparalleled full-duplex data rate transmission of 45 megabits per second (Mbps) between a moving vessel at sea and a fixed-earth station. Network and application layer tests were run concurrently with the data rate transmission trials, examining TCP/IP file transfers, video and voice transfer technologies, and Asynchronous Transfer Mode (ATM) networking techniques. This demonstration, called the Shipboard ACTS Ka-band Experiment (SHAKE), utilized a combination of commercialoff-the-shelf (COTS) and government hardware and clearly illustrated the viability of high data rate (HDR) Ka-band systems for ship-to-shore communications. Understanding of how emerging satellite services can best be used to meet Naval requirements, and how the Navy can best be positioned to use these emerging services was a critical component of this work. Underlying networking, protocol, terminal, and bandwidth-ondemand issues, combined with variable bit rate service and HDR capabilities, present challenges not typically addressed in current Naval SATCOM systems.
For ships at sea. satellites provide the only option for high data rate (HDR), long haul communications. Furthermore the demand for HDR satellite communications (SATCOM) for military and commercial ships. and other offshore platforms is increasing. Presently the bulk of this maritime HDR SATCOM connectivity is provided via C-band and X-band. However, the shipboard antenna sizes required to achieve a data rate of, say T 1 (1.544 Mbps) with present C-/X-band SATCOM systems range from seven to ten feet in diameter. This limits the classes of ships to which HDR services can be provided to those which are large enough to accommodate the massive antennas. With its high powered K/Ka-band spot beams, the National Aeronautics and Space Administration's (NASA) Advanced Communications Technology Satellite (ACTS) was able to provide T I and higher rate services to ships at sea using much smaller shipboard antennas. This paper discusses three shipboard HDR SATCOM demonstrations that were con...
Zenodo (CERN European Organization for Nuclear Research), 2001
The U.S. Navy (USN) Challenge Athena (CA) program, which provides two-way shipboard satellite communications (SATCOM) at data rates up to 1.544 Mbps (T1), utilizes the C-band frequencies: 5,925-6,425 MHz earth-tospace and 3,700-4,200 MHz space-to-earth. The International Telecommunication Union (ITU) has allocated Cband for the Fixed Satellite Service (FSS) and the point-topoint, line-of-sight microwave links of the Fixed Service (FS) on a co-primary basis throughout the world. CA is best described as a broadband Maritime Mobile Satellite Service (MMSS), a subset of the Mobile Services (MS). However, there is no ITU MS, let alone MMSS, allocation in C-band. Therefore, from a regulatory perspective, CA's operation must be done on a not-to-interfere basis, without protection from electromagnetic interference (EMI) caused by incumbent users of the band (i.e., the FS and FSS). But the USN is not alone with requirements for broadband services that must be provided throughout the oceans. Earth stations on vessels ("ESVs" as they are referred to in the ITU) are also widely used by the cruise ship and offshore oil industries. Therefore, delegates representing several broadband maritime SATCOM service providers are cooperating with FS delegates in ITU Radiocommunication Bureau (ITU-R) Working Party 4-9S to study the potential for interference from ESVs and to develop ITU-R Recommendations for ESV use of FS/FSS shared frequency bands. This paper discusses WP 4-9S' ESV-on-FS interference avoidance studies, which are currently being conducted in preparation for World Radiocommunication Conference 2003 (WRC-2003). The methods described herein could be adapted to other situations where Mobile Satellite Service (MSS) transmissions might interfere with FS and FSS systems.
2009
This article describes the architecture of two broadband satellite communication systems using a very small aperture terminal which have been installed on two Spanish oceanographic research vessels. The potential use, equipment and their characteristics are studied and compared. Analysing four parameters (jitter, round time trip, package loss and throughput), system configuration has been modified from the launch until the final optimization in order to improve TCP/IP based communications. The hardware selection is fundamental to the successful implantation of the systems, which has to guarantee the quality of satellite services. Satellite channels can affect TCP/IP protocols, but these difficulties were overcome with correct system configuration. Despite the service being operated correctly, several tests had to be done periodically to improve it and check the satellite service conditions. After the optimization of equipment configuration and network parameters on VSAT links of both vessels, effective and stable links have been obtained for Web navigation and VPN communication.
—The Advanced Communications Technology Satellite (ACTS) was conceived at the National Aeronautics and Space Administration (NASA) in the late 1970's as a follow-on program to ATS and CTS to continue NASA's long history of satellite communications projects. The ACTS project set the stage for the C-band satellites that started the industry, and later the ACTS project established the use of Ku-band for video distribution and direct-to-home broadcasting. ACTS, launched in September 1993 from the space shuttle, created a revolution in satellite system architecture by using digital communications techniques employing key technologies such as a fast hopping multibeam antenna, an on-board baseband processor, a wide-band microwave switch matrix, adaptive rain fade compensation, and the use of 900 MHz transponders operating at Ka-band frequencies. This paper describes the lessons learned in each of the key ACTS technology areas, as well as in the propagation investigations.
Student RaIg MacDonald, 3 UCSB scientists, 10 UCSB undergrads, 7 UCSB grad students, UCSB 1 sci. each from SDSU, U. of So. Carolina and OSU, 3 foreign observers (1 UABC, 2 CICESE), 2 UABC grad students, 3 SIO technicians, 1 SDSU technician. Multi-Diciplinary (2-Wheeler, OSU OSU-7 scientists, 11 technicians, 3 grad students. 1 WHOI ship) ________________ scientist, 2 WHOI technicians, 2 SIO technicians. 'Show-and-Tell CAL-Goericke, SIO Various politicos, scientists and techs to who-and-tell, etc.incl. COFI
2018
This paper presents a review of high bandwidth maritime communication technologies. High bandwidth maritime communication technologies can broadly be divided into two main areas - commercially available systems and research based systems. A detailed review of the current technology in each area is undertaken. Several commercially available systems use satellite communications technologies. A number of these systems are reviewed and bandwidth, latency and cost comparisons are made. Point to point links, another commercially available technology, is also discussed and similar criteria are used for their comparison, including range and bandwidth. As well as commercially available technologies, several novel methods of maritime communications are reviewed that are current research topics in the marine communications field. Many of these show interesting possibilities, such as evaporation ducting and tropospheric scatter. The main mode of operation of each technology is discussed, and th...
It is tricky to predict the future, especially in the maritime communications market -what are the future demands? Which technologies will be available? How will the regulatory bodies think in the future? Within this paper, the recent development towards future satellite requirements and technologies will be spotlighted. Four use case scenarios are in the focus here, namely: e-navigation, Arctic communications, autonomous ships, and evolution of GMDSS.
MILCOM 2012 - 2012 IEEE Military Communications Conference, 2012
During last year's MILCOM event (MILCOM 2011), McLain et al [1] presented a paper that provided a comprehensive comparison of Ku, commercial Ka and military Ka-band efficiencies against a number of parameters; including terminal size, regulatory restrictions, and performance in the presence of rain. This comparison showed that each band has its strengths and weaknesses, depending on the application for which it is being used (aeronautical, maritime, land based), terminal size, and operational environment (mobile and fixed). This paper provides an expanded comparison of Ku and Kaband, focusing on operational aspects and other key considerations; including coverage resilience, operational flexibility, regulatory impacts and potential regulatory changes that would improve commercial Ka-band performance, as well as the use of hybrid (multi-band) systems to further improve performance when operating in adverse weather conditions.
2021
This project was initiated in 2017 within the framework of the Spanish national research program, funded by the ministry of economics, industry and competitiveness. The scope of this project is focused on the design of ground terminals for the new generation of high-throughput satellites operating in the Ka band (from 19 to 31 GHz). These satellites have been conceived to provide high-data rate services in areas not covered by terrestrial networks, such as remote areas, war or natural disasters zones, ships or aircrafts. This
Defence Science Journal, 1993
Recent years have seen a phenomenal growth in the field of satellite communications. Satcom systems offer many advantages for military applications which include wide area coverage, rapid deployment, flexible networking and long range service ...
Acta Astronautica, 1992
Almtraet-The NASA Advanced Communications Technology Satellite (ACTS) provides high risk technologies having the potential to dramatically enhance the capabifities of the satellite communications industry. This experimental satellite, which will be launched by NASA in 1992, will furnish the technology necessary for providing a range of services. Utilizing the ACTS very high gain hopping spot beam antennas with on-board muting and processing, Very Small Aperture Terminal (VSAT) digital networks which provide on-demand, full mesh connectivity, 1.544 Mbps services with only a single hop can be estabfished. Each individual 64 kbpe voice or data circuit from a VSAT is routed by the satellite to any location on the network. Secondly, the high gain spot beams make possible voice and data aeronautical commtmication in the large frequency bandwidth which exists at 30/20 GHz. The high gain spot bemm also make feasible personal communications for low data rate services utilizing Ultra Small Aperture Terminals (USAT). Finally, the high gain spot beam antenna at Ka-band permits wide area, flexible networks providing 1 Gbps services between modest-size Earth terminals. This service is being considered in the U.S. for such applications as interconnecting supercomputers. This paper provides an overview of the ACTS and discusses the value of its technology for these communication applications including the spacecraft (S/C) weight per unit circuit for providing these services by ACTS technologies as compared to present-day satellites. For some of these services, the ACTS technologies may have more mediate application internationally rather than within the U.S.
IEEE Communications Magazine, 1999
he Space Program Office and Communication Technology Division of the NASA Glenn Research Center have been working with the United States satellite communication industry over the past 16 years to develop advanced communication and networking technologies to improve commercial satellite communications. With the recent explosion of the Internet and the enormous business opportunities available to communication system providers, great interest has developed in using commercial protocols over satellite networks. NASA Glenn has been addressing five major areas of concern regarding broadband satellite communications using commercial protocols: quality of service (QoS), interoperability, routing, traffic management, and protocol bandwidth efficiency.
2003
Abstract-The NASA Mars Reconnaissance Orbiter project and,the NASA Interplanetary Network,Directorate are collaborating to establish the first operational use of Ka- band,for telemetry,and,navigation,in a deep,space application. The objectives of the operational demonstration are to verify that the anticipated benefits of the higher carrier frequency can actually be realized under realistic operating conditions, and if possible to provide a significant enhancement,to scientific data return. We anticipate being able to demonstrate,Ka-band data rates in the range 0.5 , 4.0 Mbps,depending,on Earth-Mars distance. We,also anticipate demonstration,of significant improvements,in the accuracy of round-trip Doppler, ranging, and differenced differential one-way range (ADOR). The major open issues to be addressed in the the coming,year of design activities are: further characterization of weather statistics; selection of the operational methods,to manage,weather-induced uncertainties of link ...
2002
T h e NASA A d v a n c e d Communications Tech no logy Sat el lite (ACTS) operates at 20/30 GHz. It is scheduled for launch in the summer of 1993. The Army will experiment with ACTS to demonstrate new concepts and capabilities in support of Army AirLand Operations Doctrine. Although operating at commercial frequencies, there is much to be learned from ACTS in terms of quantifying and qualifying millimeter wavelength requirements. The role of next generation commercial satellites, and their relationship to the Military Satellite Communications (MILSATCOM) backbone, also bears investigation. One particular area of interest with ACTS is its ability to support communications on the move. The National Aeronautics and Space Administration (NASA), through the Jet Propulsion Laboratory (JPL), has already developed a commercially oriented ACTS Mobile Terminal (AMT). This vehicular terminal employs a mechanically-steered antenna, and can support either digital links up to 64 kbps or analog links. The Army has now contracted JPL to modify this terminal for Army demonstration purposes. The AMT hardware will be mounted on a High Mobility Multipurpose Wheeled Vehicle (HMMWV). In addition to providing standard baseline AMT capabilities, a coupling to a Single Channel Ground Air Radio System (SINCGARS) radio will enable secure command and control on the move. The rationale, design, features, and planned demonstration program for this Army AMT (AAMT) are discussed in this paper.
Signals and Communication Technology, 2008
In this paper we analyze the emergence of new system architectures and products that are able to deliver broadband services into mobile environments using Ku-band. In particular, we analyze the latest technological solutions that have been developed to cope with the stringent requirements of a mobile environment. Such solutions have brought broadband to environments such as business jets, commercial aircrafts, trains, and cars, which are today the new frontiers where broadband MSS can be offered.
IEEE Microwave Magazine, 2009
Current maritime systems are to a large extent based on legacy a nalog VHF radios for ship-to-shore communications near port waters, and relatively low bandwidth digital satellite communications (SatCom) for longrange ship-to-ship/shore communications. The cost of bandwidth f or Sat Com networks is expected to remain high due to the cost of launching satellites into orbit and also due to the stabilizers required for presently available on-board antennas. On the other hand, the legacy VHF system comprises low bandwidth radios incapable of supporting applications requiring high data rates. Unlike the terrestrial networks, advancement in maritime communication means is severely lagging behind its land counterpart. MARINTEK is the principle investigator of the MarCom project, a joint initiative between several national and international R&D institutions, Universities and Colleges, Public Authorities and Industry, funded by the industry itself and The Norwegian Research Council's MAROFF program, which is aiming at developing a novel digital communication system platform to ensure the proliferation of innovative mobile network applications presently being widely implemented on land-based wireless systems.
OCEANS 2009-EUROPE, 2009
Current maritime systems are to a large extent based on legacy analog VHF radios for ship-to-shore communications near port waters, and relatively low bandwidth digital satellite communications (SatCom) for long-range ship-toship and ship-to-shore communications. The cost of bandwidth for SatCom networks is expected to remain high due to the cost of launching satellites into orbit and also due to the stabilizers required for presently available on-board antennas. On the other hand, the legacy VHF system comprises low bandwidth radios incapable of supporting applications requiring high data rates. Unlike the terrestrial networks , advancement in maritime networks is severely lagging behind its land counterpart. MARINTEK is the principle investigator of the MarCom project, a joint initiative between several national and international R&D institutions, Universities and Colleges, Public Authorities and Industry, funded by the industry itself and The Norwegian Research Council's MAROFF program, and aiming at developing a novel digital communication system platform to ensure the proliferation of innovative mobile network applications presently being widely implemented on land-based wireless systems
2010
Current maritime systems are to a large extent based on legacy analog VHF radios for ship-to-shore communications near port waters, and relatively low bandwidth digital satellite communications (SatCom) for long-range ship-to-ship/shore communications. The cost of bandwidth for SatCom networks is expected to remain high due to the cost of launching satellites into orbit and also due to the stabilizers required for presently available on-board antennas. On the other hand, the legacy VHF system comprises low bandwidth radios incapable of supporting applications requiring high data rates. Unlike the terrestrial networks, advancement in maritime communication means is severely lagging behind its land counterpart.
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