S band

The S band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a part of the microwave band of the electromagnetic spectrum covering frequencies from 2 to 4 gigahertz (GHz). Thus it crosses the conventional boundary between the UHF and SHF bands at 3.0 GHz. The S band is used by airport surveillance radar for air traffic control, weather radar, surface ship radar, and some communications satellites, especially those satellites used by NASA to communicate with the Space Shuttle and the International Space Station. The 10 cm radar short-band ranges roughly from 1.55 to 5.2 GHz. The S band also contains the 2.4–2.483 GHz ISM band, widely used for low power unlicensed microwave devices such as cordless phones, wireless headphones (Bluetooth), wireless networking (WiFi), garage door openers, keyless vehicle locks, baby monitors as well as for medical diathermy machines and microwave ovens (typically at 2.495 GHz). India's regional satellite navigation network (IRNSS) broadcasts on 2.483778 to 2.500278 GHz. The largest use of this band is by WiFi networks; the IEEE 802.11b and 802.11g standards use the 2.4 GHz section of the S band. These are the most widely used computer networks in the world, used globally in home and small office networks to link desktop and laptop computers, tablet computers, smartphones, smart TVs, printers, and smart speakers together and to a wireless router to connect them to the Internet, and in wireless access points in public places like coffee shops, hotels, libraries and airports to provide the public Internet access for mobile devices. Mobile Services are operated in the 2.3 GHz to 2.6 GHz range, specifically between the 2300 - 2400 MHz band and the 2500 - 2690 MHz band. Spectrum in the 3.55 - 3.7 GHz band has been auctioned off in the United States to be used for CBRS services and spectrum between 3.45 - 3.55 GHz and 3.7 - 3.98 GHz has been auctioned off by the FCC for 5G although this spectrum is referred to as C Band by the agency.