C band (IEEE)

The C band is a designation by the Institute of Electrical and Electronics Engineers (IEEE) for a portion of the electromagnetic spectrum in the microwave range of frequencies ranging from 4.0 to 8.0 gigahertz (GHz).^[1] However, the U.S. Federal Communications Commission C band proceeding and auction, designated 3.7–4.2 GHz as C band.^[2] The C band is used for many satellite communications transmissions, some cordless telephones, as well as some radar and weather radar systems.

The C band contains the 5.725 - 5.875 GHz ISM band allowing unlicensed use by low power devices, such as garage door openers, wireless doorbells, and baby monitors. A very large use is by the high frequency (5.2 GHz) band of Wi-Fi (IEEE 802.11a) wireless computer networks. These are the most widely used computer networks in the world, used to allow laptops, smartphones, printers and TVs to connect to the internet through a wireless router in home and small office networks, and access points in hotels, libraries, and coffee shops.