IR Infrared

Infrared radiation, or simply infrared or IR, is electromagnetic radiation (EMR) with longer wavelengths than those of visible light, and is therefore invisible, although it is sometimes loosely called infrared light. IR data transmission is employed in short-range communication among computer peripherals and personal digital assistants.


IrDA refers to a complete set of protocols for wireless infrared communications. The main reason for using IrDA had been wireless data transfer over the “last one meter” using point-and-shoot principles. Thus, it has been implemented in portable devices such as mobile telephones, laptops, cameras, printers, and medical devices. Main characteristics of this kind of wireless optical communication is physically secure data transfer, line-of-sight (LOS) and very low bit error rate (BER) that makes it very efficient.

  • IrPHY (Infrared Physical Layer Specification)
  • IrLAP (Infrared Link Access Protocol)
  • IrLMP (Infrared Link Management Protocol))
  • Tiny TP (Tiny Transport Protocol)
  • IrLAN (Infrared Local Area Network)
  • IrSimple

IrDA was popular on PDAs, laptops and some desktops from the late 1990s through the early 2000s. However, it has been displaced by other wireless technologies such as Wi-Fi and Bluetooth, favored because they don’t need a direct line of sight and can therefore support hardware like mice and keyboards. It is still used in some environments where interference makes radio-based wireless technologies unusable.

An attempt was made to revive IrDA around 2005 with IrSimple protocols by providing sub-1-second transfers of pictures between cell phones, printers, and display devices. IrDA hardware was still less expensive and didn’t share the same security problems encountered with wireless technologies such as Bluetooth. For example, some Pentax DSLRs (K-x, K-r) incorporated IrSimple for image transfer and gaming.