What Is Infrared Networking and How Does It Work?

IR technology preceded Bluetooth and Wi-Fi for transferring files

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In its prime during the 1990s, infrared (IR) technology allowed computers and other electronic devices to communicate via short-range wireless signals. Using IR, computers could transfer files and other digital data bidirectionally as long as both devices were equipped with an IR sensor. The infrared transmission technology used in computers was similar to that used in consumer-oriented TV remote control units. Since then, the much faster and far more versatile Bluetooth and Wi-Fi technologies replaced IR.

Installation and Usage

Computer infrared network adapters both transmit and receive data through ports on the rear or side of a device. Infrared adapters were installed in many laptops and personal hand-held devices. In Microsoft Windows, infrared connections were created through the same method as other local area network connections.

Infrared networks were designed to support direct two-computer connections only, and those were created temporarily as the need arose. Extensions to infrared technology, however, supported more than two computers and semipermanent networks.

Infrared in Windows Vista

IR Range

Infrared communications span only short distances. When networking two infrared devices, they must be within a few feet of each other. Unlike Wi-Fi and Bluetooth technologies, infrared network signals cannot penetrate walls or other obstructions and work only within a direct line of sight. Anything that blocks that direct line between two IR devices also blocks IR communication.


Infrared technology used in local networks exists in three forms that are recognized by the Infrared Data Association (IrDA):

  • IrDA-SIR: Slow-speed infrared that supports data rates up to 115 Kbps.
  • IrDA-MIR: Medium-speed infrared that supports data rates up to 1.15 Mbps.
  • IrDA-FIR: High-speed infrared that supports data rates up to 4 Mbps.

Other Uses for Infrared Technology

Although IR no longer plays a role in transferring files from one computer to another, it is still a valuable technology in other fields. Among them are:

  • Night vision: Infrared amplifies light in low-light situations.
  • Art history: IR technology is used to peek through layers of paint on works of art to see what lies beneath.
  • Heating: Infrared generates and conducts heat, so it's popular in saunas, restaurant food-warming stations, and cooking appliances such as grills.
  • Thermography: IR technology determines the relative temperature of objects.
  • Weather forecasting: IR technology is used by weather satellites to determine temperature and cloud formations.