- Fixed Service Satellite
Fixed Service Satellite (or FSS), is the official classification (used chiefly in North America) for
geostationary communications satellites used for broadcast feeds for television and radio stations and networks, as well as for telephonyand data communications.
FSS satellites have also been used for
Direct-To-Home(DTH) satellite TV channels in North America since the late 1970s. This role has been mostly supplanted by direct broadcast satellite(DBS) television systems starting in 1994when DirecTVlaunched the first DBS television system. However, FSS satellites in North America are also used to relay channels of cable tv networks from their originating studios, to local cable headends and to the operations centers of DBS services (such as DirecTV and Dish Network) to be re-broadcasted over their DBS systems.
FSS satellites were the first geosynchronous communications satellites launched in space (such as Intelsat 1 (
Early Bird), Syncom 3, Anik 1, Westar 1, Satcom 1and Ekran) and new ones are still being launched and utilized to this day.
FSS satellites operate in either the
C band(from 3.7 to 4.2 GHz) or the FSS Ku bands (from 11.45 to 11.7 and 12.5 to 12.75 GHz in Europe, and 11.7 to 12.2 GHz in the United States).
FSS satellites operate at a lower power than DBS satellites, requiring a much larger dish than a DBS system, usually 3 to 8 feet for Ku band, and 12 feet or larger for C band (compared to 18 to 24 inches for DBS dishes). Also, unlike DBS satellites which use
circular polarizationon their transponders, FSS satellite transponders use linear polarization.
Systems used to receive television channels and other feeds from FSS satellites are usually referred to as
TVRO(Television Receive Only) systems, as well as being referred to as big-dish systems (due to the much larger dish size compared to systems for DBS satellite reception), or, more pejoratively, BUD, or big ugly dishsystems.
Star Choicesatellite TV service relies on FSS satellite technology in the Ku band. Primestarin the USA used Ku transponders on an FSS satellite as well for its delivery to subscribing households, until Primestar was acquired by DirecTVin 1999.
FSS and the rest of the world
The term of Fixed Service Satellite is chiefly a North American one, and is seldom used outside of the North American continent. This is because most satellites used for direct-to-home television in Europe, Asia, and elsewhere have the same high power output as DBS-class satellites in North America, but use the same linear polarization as FSS-class satellites.
Dish Network and FSS
The DiSH Network satellite TV service also relies on FSS satellite technology in the Ku band to provide the necessary additional capacity to handle local channels required by FCC must-carry rules and make room for HDTV resolution. The recently-introduced
SuperDishsystem receives circularly-polarized DBS 12.7 GHz from both 110-degree (the Echostar 8& 10 satellites) and 119-degree (the Echostar 7satellite) orbital locations as well as linearly-polarized FSS 11.7 GHz from either the 121-degree ( Echostar 9) or 105-degree ( AMC 15) orbital locations depending on consumer choice. Dish has started using 118.7-degree ( AMC-16-FSS) on their Dish 500+ and Dish 1000+ dishes. It has an oval LNB called a DP DBS/FSS Dual Band. This LNB will receive both the 119-degree and 118.7-degree satellites.
While the original DiSH Network satellites use circular polarity at 12.7 GHz, the newer Intelsat 13/Echostar 9 satellite at 121-degrees uses the older FSS technology to broadcast local channels and international packages such as the Chinese Great Wall TV Package. As a result, newer DiSH Network receivers are designed to receive both circular and linearly-polarized signals at two different intermediate frequencies from up to 5 different orbital locations.
The SuperDish has three low-noise block downconverters to accommodate the three satellites and two different technologies. SuperDish comes in two configurations: SuperDiSH 121 is for international programming (but is no longer in use) and SuperDiSH 105 is intended for high definition and for those customers in areas whose local channels are only available on the 105-degree satellite. As with other FSS technologies these signals are much lower power and as a result the SuperDiSH is a very large and lopsided appendage. However, since the SuperDiSH is under 1-meter in width it cannot be banned by homeowners' associations.
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