S band: Difference between revisions

The '''S band''' is a designation by the [[Institute of Electrical and Electronics Engineers]] (IEEE) for a part of the [[microwave]] [[radio band|band]] of the [[electromagnetic spectrum]] covering [[frequency|frequencies]] from 2 to 4&nbsp;[[gigahertz]] (GHz). Thus it crosses the conventional boundary between the [[Ultra high frequency|UHF]] and [[Super high frequency|SHF]] bands at 3.0&nbsp;GHz. The S band is used by [[airport surveillance radar]] for [[air traffic control]], [[weather radar]], surface ship [[radar]], and some [[communications satellite]]s, especiallyparticularly [[Tracking and Data Relay Satellite System|those satellites used]] by [[NASA]] to communicate with the [[Space Shuttle]] and the [[International Space Station]]. The 10&nbsp;cm [[radar]] short-band ranges roughly from 1.55 to 5.2&nbsp;GHz. The S band also contains the 2.4–2.483&nbsp;GHz [[ISM band]], widely used for low power unlicensed microwave devices such as [[cordless phone]]s, wireless headphones ([[Bluetooth]]), [[wireless networking]] (WiFi), [[garage door opener]]s, [[keyless entry|keyless vehicle locks]], [[baby monitor]]s as well as for medical [[diathermy]] machines and [[microwave oven]]s (typically at 2.495&nbsp;GHz). India's regional satellite navigation network ([[IRNSS]]) broadcasts on 2.483778 to 2.500278&nbsp;GHz.<ref>{{cite web |url=https://www.isro.gov.in/sites/default/files/irnss_sps_icd_version1.1-2017.pdf |title=Indian Regional Navigational Satellite System Signal In Space Interface Control Document for Standard Positioning Service |date=August 2017 |website=[[Indian Space Research Organization]] |access-date=8 February 2019 |archive-date=12 November 2020 |archive-url=https://web.archive.org/web/20201112023003/https://www.isro.gov.in/sites/default/files/irnss_sps_icd_version1.1-2017.pdf |url-status=dead }}</ref>

In May 2009, [[Inmarsat]] and [[Solaris Mobile]] (a joint venture between [[Eutelsat Communications|Eutelsat]] and [[SES S.A.(company)|SES]] ([[EchoStar Mobile]])) were each awarded a 2×15&nbsp;MHz portion of the S band by the [[European Commission]].<ref>{{cite web |url=http://europa.eu/rapid/pressReleasesAction.do?reference=IP/09/770 |title=Press release - European Commission paves the way for European mobile satellite services |date=14 May 2009 |website=[[Europa.eu]] |access-date=1 April 2018}}</ref> The two companies are allowed two years to start providing pan-European MSS services for 18 years. Allocated frequencies are 1.98 to 2.01&nbsp;GHz for Earth to space communications, and from 2.17 to 2.2&nbsp;GHz for space to Earth communications.<ref>{{cite web |url=http://www.erodocdb.dk/docs/doc98/Official/Pdf/6262008EC.pdf |title=Decision No 626/2008/EC of the European Parliament and of the Council of 30 June 2008 on the selection and authorisation of systems providing mobile satellite services (MSS) |website=[[European Communications Office]] |access-date=1 April 2018 |url-status=dead |archive-url=https://web.archive.org/web/20170630060054/http://www.erodocdb.dk/docs/doc98/Official/Pdf/6262008EC.pdf |archive-date=30 June 2017}}</ref> The Eutelsat [[W series (satellites)|W2A]] satellite was launched in April 2009 and is located at 10° East.

[[IndoStar-1]] was the world's first commercial communications satellite to use S-band frequencies for broadcast, which efficiently penetrate the atmosphere and provide high-quality transmissions to small-diameter 80 cm antennas in regions that experience heavy rainfall such as Indonesia. SimilarA performance is not economically feasible with comparablesimilar Ku- or C-band DTHreception satelliteperformance systemsrequires sincegreater moretransmission power is requiredor inmuch theselarger bandsdish to penetrate the moist atmosphere.

In the United States, the 3.55 to 3.7&nbsp;GHz band is becoming shared spectrum under rules adopted by the [[Federal Communications Commission]] in April 2015 as a result of the [[National Broadband Plan (United States)]]. The biggest user of CBRS ([[Citizens Broadband Radio Service]]) spectrum is the [[United States Navy]].<ref>{{cite journal |title=CBRS Spectrum Could Open Windows of Opportunity for Cable Ops |last=Baumgartner |first=Jeff |journal=[[Broadcasting & Cable]] |date=October 23, 2017 |page=18}}</ref><ref>{{cite news |url=https://www.networkworld.com/article/3180615/mobile-wireless961402/faq-what-in-the-wireless-world-is-cbrs.html |title=FAQ: What in the wireless world is CBRS? |last=Brown |first=Bob |work=Network World |date=March 14, 2017 |access-date=January 11, 2018}}</ref> Cable companies are planning to use the band for [[wireless broadband]] in rural areas, with [[Charter Communications]] beginning tests of the service in January 2018.<ref>{{cite journal |title=Charter Puts Wireless Broadband to the Test |last=Baumgartner |first=Jeff |journal=Broadcasting & Cable |date=February 5, 2018 |page=22}}</ref>