Monday, 20 June 2011

What Is IrDA?

What Is IrDA?


This is an acronym for Infrared Data Association. The group has been in existence since 1993, helping to set communications standards in a very specific field – infrared technology for communication over small distances. But even in this seemingly limited field there is a lot of activity for organizations like IrDA.

Infrared devices have improved considerably through the years. One of the original uses was with TV remote control units that sent the beam in one direction – to the television set. IrDA has been part of the program that set new standards for devices that work in both directions. New uses include: digital cameras, cell phones, wireless printers etc.

Two factors have combined to make infrared devices inexpensive – reduction in size and mass-manufacturing techniques. One of the standards set in this area of technology is distance for infrared devices to cover – three feet. In practice, however, some reach up to 10 feet. Signals may travel quite a bit faster in the near future, though some are now equal to the speed of a parallel printer port. IrDA speeds range from 9600 bps to 4 Mbps.

IrDA specifications include IrPHY (Infrared Physical Layer Specification), which is the foundation for standards in this area. Requirements are set for distance, modulation, speed and angle. Above this basic guideline are Infrared Link Access Protocol or IrLAP and Infrared Link Management Protocol or IrLMP. The IrLAP standards are similar to protocols used for finding and connecting computers, but apply to IrDA devices. IrLMP includes methods for discovering data channels, among other information.

IrDA has also set optional protocol descriptions for IrDA devices that may work with a LAN (local area network). Among these optional standards are those that cover data interference and use of cell phones and the personal digital assistant (PDA). Uses include paying for everyday services such as mass transportation.

If this isn’t enough to explain what IrDA is, think of the organization as helping create a structure for efficient radio communication, but in a specific area. The devices using IrDA standards use a tightly focused beam of light in a narrow spectrum. Compared to the speed of some electronic signals, infrared devices communicate in the range of trillions of hertz. *Hertz is the standard used for measuring cycles per second.

Some of the more common uses for infrared are: laptop computer connection to other devices; PDAs; digital cameras; cell phones. The user of a laptop computer might send a document to a nearby printer without having to connect by USB or other cable. Personal calendar and business schedule information may be transferred from one computer to another, possibly from a PDA to a computer.

To ensure that these connections work well, organizations such as IrDA must set minimum standards, allowable standards and protocols for specific connections. Manufacturers must construct microchips specifically for infrared devices, basing their design on standards from groups such as IrDA. Technology may allow devices to communicate over distances of more than 10 feet. In some uses, connections may be made up to a mile away.

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