VSAT

VSATs are used by car dealerships affiliated with manufacturers such as Ford and General Motors for transmitting and receiving sales figures and orders, as well as for receiving internal communications, service bulletins, and interactive distance learning courses from manufacturers. The Astra2Connect has an all-in-one OMT/BUC/LNA that looks like a QUAD LNB in shape and size which mounts on a regular TV sat mount.

Ku Band VSATs make up the vast majority of sites in use today for data or telephony applications. The largest VSAT network (more than 12,000 sites) was deployed by Hughes Network Systems, Spacenet and MCI for the US Postal Service. Other large VSAT network users in the USA include Walgreens Pharmacy, Dollar General, Wal-Mart, CVS, Riteaid, Yum! Brands (Taco Bell, Pizza Hut, Long John Silver s and other Quick Service Restaurant chains),Intralot, GTECH, GI Terminal http://gitech.in and SGI for lottery terminals.

Annual VSAT service revenues were $3.88 billion (source: www.comsys.co.uk). Most VSAT networks are configured in one of these topologies: Advantages Disadvantages Advances in technology have dramatically improved the price/performance equation of FSS (Fixed Service Satellite) over the past five years. VSATs are also used for transportable, on-the-move (utilising phased array antennas) or mobile maritime communications. The first commercial VSATs were C band receive-only systems by Equatorial Communications using spread spectrum technology.

As of December 2004, the total number of VSATs ordered stood at over 1 million, with nearly 650,000 in service. These services are used across the world as a means of delivering broadband Internet access to locations which cannot get less expensive broadband connections such as ADSL or cable internet access; usually remote or rural locations. Nearly all VSAT systems are now based on IP, with a very broad spectrum of applications.

A Very Small Aperture Terminal (VSAT), is a two-way satellite ground station with a dish antenna that is smaller than 3 meters. VSAT specific training includes: Satellite radio · Relay satellite · Transponder · Satellite Internet access · Very small aperture terminal · Satellite phone · List of communications satellite firsts · List of communication satellite companies · Earth station · Satellite dish · more.. .

These systems are applicable for providing various high-quality services because they create efficient communication systems, both for residential and business users. All the outdoor parts on the dish are collectively called the ODU (Outdoor Unit), i.e. FSS satellite systems provide various applications for subscribers, including: telephony, fax, television, high speed data communication services, Internet access, Satellite News Gathering (SNG), Digital Audio Broadcasting (DAB) and others.

New VSAT systems are coming online using Ka band technology that promise higher bandwidth rates for lower costs. FSS satellite systems currently in orbit have a huge capacity with a relatively low price structure. Most VSAT antennas range from 75 cm to 1.2 m.

As a consequence it is only 500 mW compared with the normal 2W, thus is poorer in rain. Modern VSAT systems are a prime example of convergence, and hence require skills from both the RF and IP domains. Equatorial later developed a C band (4/6 GHz) 2 way system using 1 m x 0.5 m antennas and sold about 10,000 units in 1984-85. In 1985, Schlumberger Oilfield Research co-developed the world s first Ku band (12-14 GHz) VSATs with Hughes Aerospace to provide portable network connectivity for oil field drilling and exploration units.

VSATs access satellites in geosynchronous orbit to relay data from small remote earth stations (terminals) to other terminals (in mesh configurations) or master earth station hubs (in star configurations). VSATs are most commonly used to transmit narrowband data (point of sale transactions such as credit card, polling or RFID data; or SCADA), or broadband data (for the provision of Satellite Internet access to remote locations, VoIP or video). OMT to split signal between BUC and LNB.

Data rates typically range from 56 Kbit/s up to 4 Mbit/s. More than 30,000 60 cm antenna systems were sold in the early 1980s.

The IDU is effectively a Modem, usually with ethernet port and 2 x F-connectors for the coax to BUC(Transmit) and from LNB (Receive). The FordStar network, used by Ford and its local dealers, is an example of this. VSAT technology is also used for two-way satellite Internet providers such as Hughes Network Systems, StarBand and WildBlue in the United States; and ASTRA2Connect across Europe.