(Infrared Data Association, Walnut Creek, CA, www.irda.org) A membership organization founded in 1993 and dedicated to developing standards for wireless, infrared transmission systems between computers. With IrDA ports, a laptop or PDA can exchange data with a desktop computer or use a printer without a cable connection. IrDA requires line-of-sight transmission like a TV remote control. IrDA products began to appear in 1995. The LaserJet 5P was one of the first printers with a built-in IrDA port.
Speeds and Protocols
IrDA is made up of the IrDA Serial IR physical layer (IrDA-SIR), which provides a half-duplex connection of up to 115.2 Kbps. This speed allows the use of a low-cost UART chip; however, higher non-UART, high-speed extensions up to 4 Mbps for Fast Infrared (FIR) have also been defined. IrDA uses the Infrared Link Access Protocol (IrLAP), an adaptation of HDLC, as its data link protocol. The Infrared Link Management Protocol (IrLMP) is also used to provide a mechanism for handshaking and multiplexing of two or more different data streams simultaneously.
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