Infrared (IR) remote control devices enable consumers to control electronic equipment, like televisions, DVD players and stereos without touching the component. Instead, a hand-held control unit beams a light signal to a receiver on the equipment. There are as many protocols for infrared remote control as there are electronics manufacturers.
Phillips has its RC-5, RC-6, RC-MM and RECS80 protocols for the infrared remote controls it manufactures. JVC, Panasonic, ITT, NEC, Sharp, Daewoo, Matsushita and JCC all have their own proprietary protocols. Nokia has its NRC17 protocol, and Sony has its SIRC protocol. The difference between various protocols is that they use different code tables.
All of the proprietary protocols have much in common. They all operate by flashing a Light Emitting Diode (LED) at "near Infrared." In all cases, the wavelength of the light emitted is between 850 and 950nm (nanometres). The devices require a line of sight with the sensor, which is situated on the front of the controlled device. The light pulses a digital code. Each code represents a required instruction.
The Infrared Data Association (IrDA) was formed to promote Infrared capabilities and create more complicated data exchange. The growth and acceptance of these standards was drastically reduced by the creation of Bluetooth and Wi-Fi, two wireless standards that do not require the direct line-of-sight IR requires.