Wireless Infrared

Infrared Technology

As shown in Fig. 1.0, infrared radiation is the region of the electromagnetic spectrum between microwaves and visible light. In infrared communication an LED transmits the infrared signal as bursts of non-visible light. At the receiving end a photo-diode or photoreceptor detects and captures the light pulses, which are then processed to retrieve the information they contain. Some common applications of infrared technology are listed below.

      1. Augmentative communication devices
      2. Car locking systems
      3. Computers
        a. Mouse
        b. Keyboards
        c. Floppy disk drives
        d. Printers
      4. Emergency response systems
      5. Environmental control systems
        a. Windows
        b. Doors
        c. Lights
        d. Curtains
        e. Beds
        f. Radios
      6. Headphones
      7. Home security systems
      8. Navigation systems
      9. Signage
      10. Telephones
      11. TVs, VCRs, CD players, stereos
      12. Toys

Infrared technology offers several important advantages as a form of wireless communication. Advantages and disadvantages of IR are first presented, followed by a comparative listing of radio frequency (RF) advantages and disadvantages.

 

IR Advantages:

  1. Low power requirements: therefore ideal for laptops, telephones, personal digital assistants
  2. Low circuitry costs: $2-$5 for the entire coding/decoding circuitry
  3. Simple circuitry: no special or proprietary hardware is required, can be incorporated into the integrated circuit of a product
  4. Higher security: directionality of the beam helps ensure that data isn't leaked or spilled to nearby devices as it's transmitted
  5. Portable
  6. Few international regulatory constraints: IrDA (Infrared Data Association) functional devices will ideally be usable by international traveller’s, no matter where they may be.
  7. High noise immunity: not as likely to have interference from signals from other devices

    8.  

    IR Disadvantages:

  8. Line of sight: transmitters and receivers must be almost directly aligned (i.e. able to see each other) to communicate.
  9. Blocked by common materials: people, walls, plants, etc. can block transmission
  10. Short range: performance drops off with longer distances.
  11. Light, weather sensitive: direct sunlight, rain, fog, dust, pollution can affect transmission.
  12. Speed: data rate transmission is lower than typical wired transmission.

           
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Copyright © 1997 Derek Mc Donnell.
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Last updated 07-Apr-1998.		 email the webmaster with comments or problems