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XXI Meeting of COM/CITEL will be held in Washington, DC, USA from December 7 to 9, 2009 |
Report
of Collection of VSAT Network Applications in the Americas(Document submitted by the presidency of the work group on very small aperture terminals (VSAT) in the Americas )
The globalization of economies, the need to offer international quality services, and technological and organizational reconversion processes occurring around the world under competitive conditions never seen before, have a unique impact on the telecommunications sector.
The need to satisfy new markets in the short term and, at a competitive cost as compared to other telecommunication service options, has strengthened VSAT networks.
Technological developments have made it possible to overcome limitations above all in the area of satellite applications. Developments and innovations in this area bring us continually closer to a convergence of technologies.
Experience indicates that applications of these networks cannot be separated from those of other telecommunications systems, given that they work together, and are complementary services.
This report includes a collection of VSAT network applications in the Americas as established at the XI CITEL Meeting, which was held in Lima, Perú, from September 16 to 20, 1998. At such meeting it was agreed that VSAT networks working grouping the Americas should compile all VSAT network applications in the Americas, using as a reference the document on VSAT networks - which was submitted by said group for the consideration of the Administrations in August 1995.
Since the first artificial satellites were launched at the end of the 1950´s and the beginning of the 1960´s, one of the initial applications that emerged was the implementation of voice links. Satellite transmissions then had great success, which led to a new generation of smaller satellite stations that could be rapidly implemented and installed at a lower cost, thereby providing greater facilities to users. This frame of reference established a new concept that was later materialized with the implementation of the VSAT stations.
Several technical and legal limitations had to be overcome during this process, until at the end of 1983, the first interactive VSAT systems were introduced in North America. Commercial Operations were initiated during the second half of 1985, and became the second generation of VSAT networks.
The third generation appeared in 1987, with the following characteristics:
VSAT networks constitute a step forward in adaptation the supply of service offered by telecommunication operators via satellite, to the specific needs of businesses.
They are easily installed at users facilities, regardless of how far and remote they might be. This is possible due to their small size, and given that the only requirements are being in the satellites line of sight, beam coverage, and use of Transmission/Reception plan.
VSAT network characteristics include the following:
The space component is comprised of a geostationary satellite, amplifying and changing reception frequencies, providing bandwidth and power electromagnetic resources, which are clearly subject to technical and legal limitations.
The land component consists of a central station or Hub and remote VSAT stations.
The Hub has the function of centralizing, switching, and adapting communications and managing satellite resources by means of fixed allocation, or on demand communication channels, generating network signaling, network supervision and control, remote station configuration, statistical accounting and generation of reports corresponding to the access, traffic, alarms, maintenance parameters, etc. These latter functions are usually concentrated within a network independent management center, which is a facility linked to the network Hub by the operating entities.
These are satellite communication services which make it possible to control access to communication channels, allowing dynamic channel allocation in station pairs, and the creation of mesh networks.
For these services, a control channel allows stations to request the allocation of a pair of frequencies to communicate with any other stations in the network. Once the communication is concluded, the channel is free to be reused by any other station pairs.
The antennae in these stations are characterized by their small diameter (0.7 to 2.8 m) and the fact that the system can operate in C, Ku and Ka bands.
TDM/TDMA services provide communications between a central location and multiple remote locations in what is called star topology. This star topology involves a shared earth station, called HUB, and various remote stations, called VSAT.
From the central location it is possible to monitor and control the operation of all the parts in the system. These services can operate in the C, Ku and Ka bands.
In this location, all equipment is redundant and antenna diameter of the HUB varies from 5.9 to 9 m. Voice, data and video channels to be transported to remote stations are sent to this location.
Since 1995, VSAT network applications in the Americas can be summarized as follows:
Satellite telecommunication techniques through earth stations offer the public a series of services ranging from high capacity international public telephony to private commercial services, some of which are discussed below:
At present, main banking and finance institutions of the major cities in Latin American use VSAT networks extensively for data and voice transmission.
The VSAT networks connect the database centers reliably with the different agencies and branches. Therefore the capacity for reinstallation and configuration is very important for these institutions.
An important application of satellite networks is the broadcasting systems, which permits one-way data or highly reliable audio transmissions.
This is an extremely useful application in the industry of news and stock market information distribution.
These networks send bulletins and continually update information on stock prices and capital markets in the main decision-making centers.
VSAT networks also have applications for the retail environment or points of sale, such as supermarket chains, fast food chains, drugstores and stores that constantly control sales and operations for each branch.
The use of these networks is very important in the area of car sales. Car sales representatives around the world use the VSAT network to receive information on orders,inventory restocking, consultations with the manufacturing plants and administrative operations.
Data gathered from the SCADA system can be transmitted to a database control center and processes can be controlled from a distance.
A typical case is that of the oil industry in drilling areas. It is also commonly used to oversee polyducts. In production of crude oil and its derivatives can be associated with national distribution and consumption, thanks to automation systems interconnected from a great distance via TDM/TDMA VSAT services.
The increase of LAN networks at the corporate level and the facilities offered to users requires an interconnection of these networks, often covering large distances.
Satellite communication systems make this connection possible, thereby allowing information transfer, shared use of distributed resources and remote access to data base servers.
Videoconferencing allows corporations with branches in different geographic locations to meet without the costs or risks of participant travel.
This saves time, which is key to the success of modern companies. In addition to the transmission of images and voices it is possible to send digitized documents.
The VSAT system can have a better cost-effective relationship for data and voice connectivity than the traditional system using the public network of PSTN switching.
With an adequate design, the VSAT system can have a superior perfomance measured in error-free seconds and availability than the PSTN transport system.
Multicast videoconferencing (one or various sites):
Information and database access: Internet, e-mail, electronic news, hotline services, etc.
Information superhighways are becoming the focus of communications for the next century.
Coverage beyond the PSTN system.
Speedy installation.
Low operation and maintenance costs.
Easy reconfiguration and expansion.
Network interface flexibility.
Used to bypass the PSTN in countries with deficient land networks.
Department stores: inventory control, prices, advertising, etc.
Reservation Systems: Hotel chains, Travel Agencies, Car Rental Agencies, etc.
Finance and banking sector.
Credit and debit card authorizations: Points of sale and ATM’s.
Supervising systems: Monitoring and SCADA.
Lottery agencies.
Stock markets.
Distance education and training: P-P, P-MP.
There are other videoconferencing applications, such as seminars and courses, which allow all participants to be included.
SCADA applications, designed for the acquisition of remote data control in non-serviced locations.
Within this market segment, environmental applications to obtain data information on water and air quality, are being implemented using space satellites with coverage for the Americas.
Environmental applications of the VSAT network also include fire detection through infrared sensors and video cameras, to determine hot spots on geographic location.
Tele Medicine applications via satellite will permit the diagnostic of x-rays by major hospitals for smaller health centers lacking radiologists. This service will greatly improve health services and will reduce medical costs.
In the field of airport infrastructure and air navigation the application offers the service of data collection from secondary radar in remote places and transmission to air traffic control center via satellite. This process will improve air traffic control infrastructure.Telephony demand in rural areas in developing countries will be quickly met through VSAT networks due to the availability and cost competitiveness of these networks.
Tele Education is a cutting-edge application for the countries in the Americas that aspire to develop and offer these services.
Audio signal distribution for radio stations.
News distribution from the agencies to their clients.
Supervision and control of oil pipeline infrastructure.
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