Wireless communication in Terril may be used to transfer information over short distances (say, a few meters as in television remote control) or long distances (like thousands or millions of kilometers for radio communications). It includes various types of fixed, mobile and portable two-way radios, cellular telephones, personal digital assistants and wireless networking. Other examples of wireless technology include garage door openers, wireless computer mice, keyboards, and headsets, cordless telephones and satellite television. They permit services that are impossible to implement with the use of wires, such as a long range communication. These services use some form of energy like radio frequency, infrared light, laser light, visible light, acoustic energy, etc, to transfer information without the use of wires.