Infrared (IR) wireless technology is a low-power, short-range wireless technology. IR transmits data using LEDs and receives data using photodiodes. IR wireless networks are globally unregulated. However, the Infrared Data Association (IrDA) defines the specifications for IR wireless communication. Figure 1 lists common IR characteristics.
Three common types of IR networks:
- Line of sight - The signal is transmitted only if there is a clear, unobstructed view between devices.
- Scatter - The signal is bounced off ceilings and walls.
- Reflective - The signal is sent to an optical transceiver and is redirected to the receiving device.
Setting up and configuring IR devices is simple. Many IR devices connect to the USB port on a laptop or desktop computer. When the computer detects the new device, Windows 7 installs the appropriate drivers. The installation is similar to setting up a LAN connection.
IR is a practical, short-range connection solution, but it has some limitations:
- IR light cannot penetrate ceilings or walls.
- IR signals are susceptible to interference and dilution by strong light sources, such as fluorescent lighting.
- Scatter IR devices can connect without the line of sight, but data transfer rates are lower and distances are shorter.
- IR distances should be 3 feet (1 m) or less when used for computer communications.
Before installing and configuring a device, make sure that IR is enabled in the BIOS by following these steps:
Step 1. Turn on the device to make it discoverable to Windows.
Step 2. Align the devices.
Step 3. When the devices are correctly aligned, an icon appears on the taskbar with a pop-up message.
Step 4. Click the pop-up message to display the Infrared dialog box.
Laptops without an internal IR device can connect a serial IR transceiver to a serial port or USB port. Figure 2 shows an internal IR port transceiver.
You can also access the Infrared dialog box in the Control Panel. You can configure the following settings:
- Infrared - Control how you are notified about an IR connection, and control how files are transferred.
- Image Transfer - Control how images are transferred from a digital camera.
- Hardware - Lists IR devices that are installed on the computer.