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 technology allowed computing 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 the necessary IR sensor. The infrared transmission technology used in computers was similar to that used in consumer product remote control units. Infrared was replaced in modern computers by the much faster Bluetooth and Wi-Fi technologies.

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 handheld 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 when the need arose. However, extensions to infrared technology supported more than two computers and semi-permanent networks.

IR Range

Infrared communications span short distances. It is necessary to place two infrared devices within a few feet of each other when networking them. Unlike Wi-Fi and Bluetooth technologies, infrared network signals cannot penetrate walls or other obstructions and work only with a direct line of sight.


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 – fast speed infrared that supports data rates up to 4 Mbps

Other Uses for Infrared Technology

Although IR no longer plays a large role in transferring files from one computer to the next, 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 beneath layers of paint on artwork to see what lies beneath.
  • Heating. Infrared can generate and conduct heat. Infrared is popular in saunas and restaurant food-warming stations.
  • Thermography. IR technology determines the relative temperature of objects.
  • Weather forecasting. IR technology is used by weather satellites to determine temperature and cloud formations.