Satellite phone

[[File:Iridium Satellite Phone.jpg|thumb|An Iridium satellite phone, late 1990s]]

A '''satellite phone''' (also called a '''satellite telephone''' or '''satphone''') is a type of [[mobile phone]] that connects to the [[public switched telephone network]] through orbiting [[satellite]]s instead of terrestrial [[cell site]]s. They function in areas without terrestrial network coverage but require line-of-sight to a satellite. Most support voice, text, and low-bandwidth data services.

== Uses == Satellite phones are used in areas where conventional communication infrastructure is unavailable or has been disrupted. Typical applications include maritime and aviation communication, remote expeditions, mining, logistics, and emergency response.<ref>{{cite web |date=28 August 2018 |title=Satellite phone: sectors where they are commonly used |url=https://axessnet.com/en/satellite-phone-know-the-5-sectors-that-use-them-the-most/ |access-date=13 January 2023 |website=Axessnet |language=en}}</ref>

== Equipment == Early handsets were large and required deployable antennas, while later models are comparable in size to ordinary [[smartphones]]. Fixed ship and vehicle installations use directional [[microwave]] antennas that track satellites automatically. Smaller systems may rely on [[Voice over Internet Protocol|VoIP]] over [[satellite internet]] links such as [[BGAN]] or [[VSAT]]. Indoor reception is limited and may require external antennas or repeaters. More recently, unmodified smartphones with no special support for satellite communication are also able to be used for ''direct-to-phone'' satellite telephony.<ref>{{Cite web |title=Spacex starlink direct-to-cell |url=https://www.spacex.com/updates#dtc-gen2-spectrum |archive-url=https://web.archive.org/web/20251104215903/https://www.spacex.com/updates |archive-date=2025-11-04 |access-date=2025-11-05 |website=SpaceX |language=en-US}}</ref><ref>{{Cite web |title=Wayback Machine |url=https://api.starlink.com/public-files/DIRECT_TO_CELL_FIRST_TEXT_UPDATE.pdf |archive-url=https://archive.today/20250908195912/https://www.spacex.com/updates%23dtc-gen2-spectrum |archive-date=8 September 2025 |access-date=2025-11-05 |website=api.starlink.com}}</ref>

[[File:Globalstar GSP-1600 satellite phone.jpg|thumb|Globalstar GSP-1600 satellite phone, 2024]]

== History == The first voice signals relayed via satellite were transmitted in 1958 using the experimental [[SCORE (satellite)|SCORE]] satellite, soon after the launch of [[Sputnik 1]]. [[MARISAT]] (1976) became the first dedicated mobile communications satellite and was later integrated into the [[Inmarsat]] organization, founded in 1979.<ref name="m714">{{cite web |last=Whalen |first=David J. |title=Communications Satellites: Making the Global Village Possible |website=NASA |date=30 November 2010 |url=https://www.nasa.gov/history/communications-satellites/ |access-date=28 September 2024}}</ref>

== Satellite networks == Satellite telephony systems operate mainly through two orbital types: [[geostationary orbit]] (GEO), about {{convert|35,786|km|mi}} above Earth, and [[low Earth orbit]] (LEO), about {{convert|640|to|1120|km|mi}}. The orbit determines coverage area, latency, and terminal design.

=== Geostationary systems === [[File:USNS Kingsport SYNCOM Call Kennedy-Balewa July 1963.png|thumb|Prime Minister Abubakar Tafawa Balewa speaking with President John F. Kennedy via the [[SYNCOM]] satellite, 1963]] GEO satellites appear fixed in the sky, allowing near-global coverage with few satellites. The long signal path introduces latency but supports higher data throughput than LEO networks. GEO service is reliable up to roughly 70° latitude; signal quality decreases near the poles or in obstructed terrain.

Notable GEO-based operators include: * [[ACeS]] – Indonesia-based operator active 2000–2014 * [[Inmarsat]] – Founded 1979, provides global coverage except polar regions * [[Thuraya]] – UAE-based, operating since 1997 across Europe, Africa, Asia, and Australia * [[MSAT]] / [[SkyTerra]] – North American operator offering mobile and fixed terminals * [[Terrestar]] – U.S. operator using geosynchronous orbit * [[Tiantong (Satellite)|Tiantong]] – Chinese GEO system for regional voice and messaging services

=== Low Earth orbit systems === [[File:Satellite telephony RD-TD diagram.png|thumb|Simplified satellite telephony link diagram]] LEO satellites orbit Earth every 70–100 minutes. Continuous service requires constellations of dozens of satellites, as each satellite remains visible for only several minutes.<ref>{{cite web |title=Delay/Disruption-Tolerant Network Testing Using a LEO Satellite |url=http://personal.ee.surrey.ac.uk/Personal/L.Wood/publications/uk-dmc-dtn-saratoga-testing-estc-2008.pdf |archive-url=https://web.archive.org/web/20160304104010/http://personal.ee.surrey.ac.uk/Personal/L.Wood/publications/uk-dmc-dtn-saratoga-testing-estc-2008.pdf |archive-date=4 March 2016 |publisher=NASA |access-date=1 June 2022}}</ref>

Major operators: * [[Globalstar]] – 48 active satellites covering most land areas; depends on ground gateways within view of satellites * [[Iridium Communications|Iridium]] – 66 active near-polar satellites with inter-satellite links providing global coverage<ref>{{cite web |title=Iridium Communications Network and Satellite Coverage |url=https://www.roadpost.com/iridium-satellite-network |access-date=1 June 2022 |website=Roadpost USA}}</ref>

Both systems launched in the late 1990s, experienced bankruptcy, and were later restructured. Typical data speeds range from 2.4 to 9.6 kbit/s.

=== Emerging hybrid networks === In 2022, [[T-Mobile US]] and [[SpaceX]] announced a partnership using second-generation [[Starlink]] satellites to provide limited mobile coverage via existing [[LTE (telecommunication)|LTE]] spectrum.<ref>{{cite web |date=13 September 2022 |title=T-Mobile and Starlink satellite connectivity explained |url=https://www.androidauthority.com/t-mobile-starlink-satellite-connectivity-3207661/ |access-date=10 January 2023 |website=Android Authority}}</ref><ref>{{cite news |date=25 August 2022 |title=SpaceX and T-Mobile plan satellite-to-phone coverage |work=Ars Technica |url=https://arstechnica.com/science/2022/08/forget-5g-wireless-spacex-and-t-mobile-want-to-offer-zero-g-coverage/ |access-date=26 August 2022}}</ref>

[[AST SpaceMobile]] is developing a [[3GPP]]-compliant space network linking standard smartphones to satellites in areas lacking terrestrial coverage.<ref>{{cite news |title=AST SpaceMobile's prototype satellite makes first 5G connection |url=https://spacenews.com/ast-spacemobiles-prototype-satellite-makes-first-5g-connection/ |access-date=22 January 2024 |website=SpaceNews}}</ref> In 2024, [[Iridium Communications|Iridium]] announced “Project Stardust”, a planned 5G non-terrestrial service for messaging and [[Internet of things|IoT]] devices.<ref>{{cite web |title=Iridium unveils Project Stardust |url=https://investor.iridium.com/2024-01-10-Iridium-Unveils-Project-Stardust-Developing-the-Only-Truly-Global,-Standards-Based-IoT-and-Direct-to-Device-Service |access-date=22 January 2024 |website=Iridium Communications}}</ref>

== Numbering == {{See also|Global Mobile Satellite System|International Networks (country code)}} Satellite phone networks use special international numbering codes. [[Inmarsat]] numbers use +870. Historical codes +871–+874 were phased out in 2008.<ref name="Inmarsat">{{cite web |title=Dialling codes – customer support |url=http://www.inmarsat.com/Support/Calling/Dialling_codes.aspx |url-status=dead |archive-url=https://web.archive.org/web/20110322141333/http://www.inmarsat.com/Support/Calling/Dialling_codes.aspx |archive-date=22 March 2011 |access-date=7 April 2011 |publisher=Inmarsat}}</ref> LEO networks such as Iridium and Globalstar use ranges within +881, while smaller regional systems use +882 for international networks.

== Cost == Satellite communication remains significantly more expensive than terrestrial mobile service due to launch and maintenance costs. Used handsets typically cost a few hundred US dollars; new models and broadband terminals several thousand. Service fees often include a monthly base charge and per-minute rates higher than cellular equivalents.<ref>{{cite web |title=Satellite Phone Rentals and Sales |url=http://www.allroadcommunications.com/products/ |archive-url=https://web.archive.org/web/20110219005954/http://allroadcommunications.com/products/ |archive-date=19 February 2011 |access-date=7 April 2011}}</ref>

== Legal restrictions == Some governments restrict or require licences for satellite-phone use because the devices connect directly to foreign networks. Restrictions apply in countries including China, India, Myanmar, North Korea, and Russia, generally citing national security or spectrum management concerns.<ref>{{cite news |date=8 November 2017 |title=Countries where satellite phones are banned or restricted |url=https://blog.telestial.com/2017/11/08/countries-where-satellite-phones-banned-or-restricted/ |access-date=13 November 2017 |work=Telestial Blog}}</ref>

== Security == Modern satellite phone systems encrypt voice traffic, but earlier proprietary algorithms (GMR-1, GMR-2) were shown to have cryptographic weaknesses.<ref>{{cite journal |last1=Driessen |first1=Benedikt |last2=Hund |first2=Ralf |last3=Willems |first3=Carsten |last4=Paar |first4=Christof |last5=Holz |first5=Thorsten |year=2012 |title=Don't Trust Satellite Phones: A Security Analysis of Two Satphone Standards |journal=2012 IEEE Symposium on Security and Privacy |url=http://www.ieee-security.org/TC/SP2012/papers/4681a128.pdf |access-date=28 April 2013 |archive-url=https://web.archive.org/web/20130518162622/http://www.ieee-security.org/TC/SP2012/papers/4681a128.pdf |archive-date=18 May 2013}}</ref> For sensitive communication, additional encryption or secure satellite services are used.

== Role in disaster response == Satellite phones are valuable when terrestrial networks fail during natural disasters or conflicts. They have supported communication following events such as major earthquakes, hurricanes, and power outages.<ref>{{cite web |title=Preparing for Hurricane Season with Satellite Phones |url=http://www.prlog.org/10862989-when-affected-by-hurricanes-satellite-phones-ensure-safe-and-reliable-communication.html |archive-url=https://web.archive.org/web/20120924235730/http://www.prlog.org/10862989-when-affected-by-hurricanes-satellite-phones-ensure-safe-and-reliable-communication.html |archive-date=24 September 2012 |access-date=7 April 2011}}</ref> Because each satellite beam serves large regions, capacity remains limited during widespread emergencies.

== Dual connectivity smartphones == In the 2020s, some smartphones gained satellite connectivity for emergency use. [[Thuraya]] introduced the X5 Touch (2018) combining satellite and cellular communication.<ref>{{cite web |title=Thuraya X5 Touch brochure |url=https://www.thuraya.com/-/media/thuraya/rebranded/x5-touch-brochure.pdf |archive-url=https://web.archive.org/web/20240626121949/https://www.thuraya.com/-/media/thuraya/rebranded/x5-touch-brochure.pdf |archive-date=26 June 2024 |access-date=23 November 2024}}</ref> [[Apple Inc.|Apple]] added emergency satellite messaging with the [[iPhone 14]] (2022) and roadside assistance in the [[iPhone 15]] (2023).<ref>{{cite news |date=16 November 2022 |title=iPhone 14 adds SOS via satellite |url=https://www.washingtonpost.com/technology/2022/11/15/iphone-satellite-sos/ |work=The Washington Post |access-date=13 September 2023}}</ref> Such services typically support text-based communication and limited emergency data.

=== Notable dual-mode phones === * 2018 – Thuraya X5 Touch, first android and gsm satellite phone, external antenna * 2021 – Thuraya XT Lite, external antenna * 2022 – Apple iPhone 14, internal antenna, [[Globalstar]] * 2022 – Huawei Mate 50 Series, internal antenna, [[BeiDou]] * 2023 – Motorola Defy 2, internal antenna, Bullitt Satellite, [[Skylo]] for satellite messaging * 2023 – Apple iPhone 15 * 2023 – Huawei P60 Series, internal antenna, [[Tiantong (satellite)|Tiantong]] for calling * 2023 – Xiaomi 14 Pro Titanium Edition, internal antenna, Tiantong * 2024 – Thuraya Skyphone, Android smartphone with a massive pull-out/retractable antenna * 2024 – vivo X100 Ultra, internal antenna * 2024 – Huawei Pocket 2, first internal antenna [[Clamshell_design#Popularity|flip phone style]] [[foldable smartphone]] * 2024 – Oppo Find X7 Ultra Satellite Edition, internal antenna

== See also == {{Portal|Telephones}} * [[Broadband Global Area Network]] * [[Mobile-satellite service]] * [[Satellite internet]] * [[Telecommunications]]

== References == {{Reflist}}

== External links == {{Commons category|Satellite phones}} * [https://globalcomsatphone.com/history-of-the-handheld/ History of the handheld satellite phone] (GlobalCom, 2018) * [https://web.archive.org/web/20070710100616/http://www.ee.surrey.ac.uk/Personal/L.Wood/constellations/ University of Surrey – Satellite constellations overview] * [https://www.satellitephonefaq.com/ Satellite phone FAQ] (technical overview)

[[Category:Satellite telephony|*]] [[Category:Emergency communication]] [[Category:Mobile phones]] [[Category:Mobile telecommunications]]