Optical data link

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Revision as of 18:40, 21 August 2007 by Ricardo (talk | contribs) (Added categories.)
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Scope

This page covers technologies to link two places or buildings via an optical data link.

Suitable places to use an optical link

It may be useful in places where...

  • Outdoor Wi-Fi is not permitted by a county's radio legislation.
  • A line-of-site link is possible.
  • The two places to be linked are about 1.5 KM/1 Mile or less apart (with the Ronja system below).
  • Cheap hardware is required.
  • A system with no subscription-fee is required.
  • There is only occasional dense fog.

Example locations

  • School-to-school links in urban/suburban areas.
  • School-to-school links between nearby villages.
  • School to nearby ISP office link, where the phone lines don't support high-speed access.
  • Commercial Building (Business, Radio station, etc) to ISP office link, where schools are allowed internet access and to pick up files on removable media (Sneakernet).
  • Multi-stage optical links with relays from building-to-building to reach a school or village.
  • Optical network involving many schools/buildings/houses and optionally, an ISP office.

Technologies

Ronja cheap home-made optical link

The Ronja (Reasonable Optical Near Joint Access) website describes how to build a 100 US Dollar optical data link to connect two buildings up to 1.4KM/0.87 Miles apart at 10Mbps. The 'Ronja About page' describes the system (see text and the 4 .pdf files) and the 'Ronja Home page' has the equipment details. The site has designs for Printed Circuit Boards. The software is free.

The system uses an infra-red LED and lens, not a laser, so is 'eye-safe' and invisible to anyone in the area.

The system uses cheap parts, but is labor-intensive for amateurs to build. There are enough OLPC schools for it to be worthwhile having some systems mass-produced.

Other systems

Please add any other systems here.

--Ricardo 16:05, 20 August 2007 (EDT)