Editing Satellite Internet access (section)

===Satellite===
Marketed as the centre of the new broadband satellite networks are a new generation of high-powered GEO satellites positioned {{convert|35786|km|mi}} above the equator, operating in K<sub>a</sub>-band (18.3–30&nbsp;GHz) mode.<ref>{{cite web|url=http://www.fcc.gov/encyclopedia/ka-band-permitted-space-station-list |archive-url=https://web.archive.org/web/20120421053243/http://www.fcc.gov/encyclopedia/ka-band-permitted-space-station-list |url-status=dead |archive-date=2012-04-21 |title=Ka-band Permitted Space Station List |publisher=Federal Communications Commission |date=2009-01-25 |access-date=2013-08-29 }}</ref> These new purpose-built satellites are designed and optimized for broadband applications, employing many narrow spot beams,<ref>{{Cite web| title=Satellite technology primer | url=http://www.dbsinstall.com/PDF/WildBlue/Wildblue_Satellite_Basics.pdf | archive-url=https://web.archive.org/web/20100714150832/http://www.dbsinstall.com:80/PDF/WildBlue/Wildblue_Satellite_Basics.pdf | archive-date=2010-07-14}}</ref> which target a much smaller area than the broad beams used by earlier communication satellites. This spot beam technology allows satellites to reuse assigned bandwidth multiple times which can enable them to achieve much higher overall capacity than conventional broad beam satellites. The spot beams can also increase performance and consequential capacity by focusing more power and increased receiver sensitivity into defined concentrated areas. Spot beams are designated as one of two types: subscriber spot beams, which transmit to and from the subscriber-side terminal, and gateway spot beams, which transmit to/from a service provider ground station. Note that moving off the tight footprint of a spotbeam can degrade performance significantly. Also, spotbeams can make the use of other significant new technologies impossible, including 'Carrier in [[Carrier wave|Carrier]]' modulation.

In conjunction with the satellite's spot-beam technology, a [[Transponder (satellite communications)|bent-pipe]] architecture has traditionally been employed in the network in which the satellite functions as a bridge in space, connecting two communication points on the ground. The term "bent-pipe" is used to describe the shape of the data path between sending and receiving antennas, with the satellite positioned at the point of the bend.
Simply put, the satellite's role in this network arrangement is to relay signals from the end user's terminal to the ISP's gateways, and back again without processing the signal at the satellite. The satellite receives, amplifies, and redirects a carrier on a specific radio frequency through a signal path called a transponder.<ref name="howsatcomworks">{{cite web|url=http://www.vsat-systems.com/satellite-internet/how-it-works.html |title=How broadband satellite Internet works |publisher=VSAT Systems |access-date=2013-08-29}}</ref>

Some satellite constellations in LEO such as [[Starlink]] and the proposed [[Telesat]] constellation will employ [[laser communication in space|laser communication]] equipment for high-throughput optical inter-satellite links. The interconnected satellites allow for direct routing of user data from satellite to satellite and effectively create a space-based [[optical mesh network]] that will enable seamless network management and continuity of service.<ref>{{cite web|title=Elon Musk is about to launch the first of 11,925 proposed SpaceX internet satellites — more than all spacecraft that orbit Earth today|url=http://www.businessinsider.com/spacex-starlink-microsat-launch-global-internet-2018-2?r=US&IR=T|website=Business Insider|access-date=15 April 2018}}</ref>

The satellite has its own set of antennas to receive communication signals from Earth and to transmit signals to their target location. These antennas and transponders are part of the satellite's "payload", which is designed to receive and transmit signals to and from various places on Earth. What enables this transmission and reception in the payload transponders is a repeater subsystem (RF (radio frequency) equipment) used to change frequencies, filter, separate, amplify and group signals before routing them to their destination address on Earth. The satellite's high-gain receiving antenna passes the transmitted data to the transponder which filters, translates and amplifies them, then redirects them to the transmitting antenna on board. The signal is then routed to a specific ground location through a channel known as a carrier. Beside the payload, the other main component of a communications satellite is called the bus, which comprises all equipment required to move the satellite into position, supply power, regulate equipment temperatures, provide health and tracking information, and perform numerous other operational tasks.<ref name="howsatcomworks" />