A cross impact methodology for the assessment of US telecommunications system with application to fiber optics development, volume 2

The appendices for the cross impact methodology are presented. These include: user's guide, telecommunication events, cross impacts, projection of historical trends, and projection of trends in satellite communications

Satellite-aided mobile communications limited operational test in the trucking industry

An experiment with NASA's ATS-6 satellite, that demonstrates the practicality of satellite-aided land mobile communications is described. Satellite communications equipment for the experiment was designed so that it would be no more expensive, when mass produced, than conventional two-way mobile radio equipment. It embodied the operational features and convenience of present day mobile radios. Vehicle antennas 75 cm tall and 2 cm in diameter provided good commercial quality signals to and from trucks and jeeps. Operational applicability and usage data were gathered by installing the radio equipment in five long-haul tractor-trailer trucks and two Air Force search and rescue jeeps. Channel occupancy rates are reported. Air Force personnel found the satellite radio system extremely valuable in their search and rescue mission during maneuvers and actual rescue operations. Propagation data is subjectively analyzed and over 4 hours of random data is categorized and graded as to signal quality on a second by second basis. Trends in different topographic regions are reported. An overall communications reliability of 93% was observed despite low satellite elevation angles ranging from 9 to 24 degrees

Space - Satellite Communication in the 70\u27s

Space-satellite communications of the 60s will not suffice for the 70s. A refinement must occur. International emphasis for operational satellite systems demands more sophisticated systems and equipments to handle the large number of new applications arising. Payloads must include gear for weather observations, communications, navigation, reconnaissance, early warning, public health safe-guarding, and nuclear test monitoring. What direction should the communications industry take to accomplish these things ? What technological support is needed? Now is the time to take an overall view of the entire space-satellite field. Engineering during the 60s devoted attention to brute force communication technology necessary to prove feasibility and reliability. This paper examines the initial evaluation criteria and experimental results for the three categories of systems comprising this field: Satellite Communications, Spacevehicle Contained Communications, and Ground-based Tracking and Telemetry Communications. The feasibility requirements established early in the 60s form the framework from which today\u27s technique and equipment trends have developed. See Figure 1. Studying these trends provides the clue to the special problems encountered in each of the above categories

Power requirements for commercial communications spacecraft

Historical data on commercial spacecraft power systems are presented and their power requirements to the growth of satellite communications channel usage are related. Some approaches for estimating future power requirements of this class of spacecraft through the year 2000 are proposed. The key technology drivers in satellite power systems are addressed. Several technological trends in such systems are described, focusing on the most useful areas for research and development of major subsystems, including solar arrays, energy storage, and power electronics equipment

Trends in the incidence of rain height and the effects on global satellite telecommunications

Satellite communications using millimetre waves, in Ka band and above, experience significant fading by rain. Strong attenuation is experienced between the ground station and a level known as the rain height, in ITU-R recommendations assumed to be 360 m above the zero-degree isotherm (ZDI). This paper examines NOAA NCEP/NCAR Reanalysis 1 data to identify changes in the ZDI height over the last 30 years. Near the equator and the poles the ZDI height has been approximately stable over this period. However, in mid-latitudes, different regions show trends of increasing or decreasing ZDI height. Over the economically important regions of North America, China and Western Europe, the ZDI height has shown an increasing trend with peak rates in the range of 8 to 10 metres per year. Given a twenty-year life-time of a satellite system, this could lead to a 10 to 20% increase in fade intensity from a similar rain event. The effect will be compounded by increasing trends in the incidence of heavy rain recently identified in UK data. These trends will need to be considered when designing new systems

Potential markets for advanced satellite communications

This report identifies trends in the volume and type of traffic offered to the U.S. domestic communications infrastructure and extrapolates these trends through the year 2011. To describe how telecommunications service providers are adapting to the identified trends, this report assesses the status, plans, and capacity of the domestic communications infrastructure. Cable, satellite, and radio components of the infrastructure are examined separately. The report also assesses the following major applications making use of the infrastructure: (1) Broadband services, including Broadband Integrated Services Digital Network (BISDN), Switched Multimegabit Data Service (SMDS), and frame relay; (2) mobile services, including voice, location, and paging; (3) Very Small Aperture Terminals (VSAT), including mesh VSAT; and (4) Direct Broadcast Satellite (DBS) for audio and video. The report associates satellite implementation of specific applications with market segments appropriate to their features and capabilities. The volume and dollar value of these market segments are estimated. For the satellite applications able to address the needs of significant market segments, the report also examines the potential of each satellite-based application to capture business from alternative technologies

SatNEx: A Network of Excellence Providing Training in Satellite Communications

YesSatellite communications represents a specialised area of telecommunications. While the development of satellite technology is relatively slow in comparison to wireless networks evolution, due to the need for high reliability, the services that satellites are able to offer are evolving at much the same pace as their terrestrial counterparts. It is within this context that the satellite communications network of excellence (SatNEx) has evolved its initiative, the aim being to serve the engineering community with the latest technological trends, while also providing a solid grounding in the fundamentals for those new to the subject area.European Commission Framework Programme

Satellite Communications in the Navy -A Look Back and A Look Forward

It is the purpose of this paper to review the Navy\u27s efforts in the field of Satellite Communications up to the present time, to indicate some of the problem areas, and to suggest some current and possible future trends. Most of the early Navy work in the 50 f s and early 60 f s involved use of passive satellites such as the moon, reflecting balloons and the like. The moon was used to bounce communications signals between places as far away as Washington and Hawaii. Since the early 1960\u27s emphasis has steadily shifted to the use of active satellites which receive, amplify, and re-transmit signals, thus providing a much stronger signal at the receiver than the extremely faint signals reflected from the surface of the moon. As better boosters have become available, large and sophisticated satellites can be put into high altitude orbits. There is a strong trend toward synchronous orbits which cause the satellite to appear motionless over a point on the equator. From such a vantage point a satellite can see over 40% of the earth\u27s surface. Although much early work was done independently by the services, the present programs are, for the most part, joint efforts within the Department of Defense. The Navy\u27s primary area of unique responsibility is in development of satellite communication terminals suitable for use aboard naval combatant type ships. Some difficult technical problems are involved such as finding suitable room for the antennas aboard crowded ships, electromagnetic interference with other systems, etc. Also, there are system problems to be worked out together with the other services such as best modulation methods, multiple access schemes, bandwidths and other important parameters. These problems are being solved. Satellite communications shows great promise of a major improvement in the Navy\u27s vital long distance communications

Space-Air-Ground Integrated 6G Wireless Communication Networks: A Review of Antenna Technologies and Application Scenarios

A review of technological solutions and advances in the framework of a Vertical Heterogeneous Network (VHetNet) integrating satellite, airborne and terrestrial networks is presented. The disruptive features and challenges offered by a fruitful cooperation among these segments within a ubiquitous and seamless wireless connectivity are described. The available technologies and the key research directions for achieving global wireless coverage by considering all these layers are thoroughly discussed. Emphasis is placed on the available antenna systems in satellite, airborne and ground layers by highlighting strengths and weakness and by providing some interesting trends in research. A summary of the most suitable applicative scenarios for future 6G wireless communications are finally illustrated