Wireless networks allow computers to communicate without physical connections by using radio waves or infrared light. They provide mobility by freeing devices from the location constraints of wired networks. Wireless networks can be broadly categorized as fixed wireless networks, which support limited mobility of hardware within an area like a neighborhood, and mobile wireless networks, which enable full mobility and access to data from anywhere using devices like smartphones and PDAs. Common wireless technologies used include cellular networks, wireless local area networks, satellite communications, and Public Safety LTE wireless networks.