Optical data link: Difference between revisions
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This page covers technologies to link two places or buildings via an optical data link. |
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==Suitable places to use an optical link== |
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It may be useful in places where... |
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* Outdoor Wi-Fi is not permitted by a county's radio legislation. |
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* A line-of-sight link is possible. |
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* The two places to be linked are about 1.5 KM/1 Mile or less apart (with the Ronja system below). |
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* Cheap hardware is required. |
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* A system with no subscription-fee is required. |
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* There is only occasional dense fog. |
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==Example locations== |
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* School-to-school links in urban/suburban areas. |
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* School-to-school links between nearby villages. |
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* School to nearby ISP office link, where the phone lines don't support high-speed access. |
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* 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]]). |
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* Multi-stage optical links with relays from building-to-building to reach a school or village. |
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* Optical network involving many schools/buildings/houses and optionally, an ISP office. |
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* Across mountain valleys. |
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* Up a hill and down the other side using two systems. |
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==Technologies== |
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===Ronja cheap home-made optical link=== |
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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 [http://ronja.twibright.com/about.php 'Ronja About page'] describes the system (see text and the 4 .pdf files) and the [http://ronja.twibright.com/ 'Ronja Home page'] has the equipment details. The site has designs for Printed Circuit Boards. The software is free. |
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The system uses an LED and lens, not a laser, so is 'eye-safe'. There is one version using a visible red LED and another using an invisible infra-red LED. Both are invisible to anyone in the area who is not in the direct line between the two sender/receiver units. |
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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. |
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See [http://en.wikipedia.org/wiki/RONJA Wikipedia: RONJA] and [http://ronja.twibright.com/about.php Ronja About page] for more details and photos. |
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===Other systems=== |
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Please add any similar systems here. |
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--[[User:Ricardo|Ricardo]] 16:31, 23 August 2007 (EDT) |
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==== laser and aui ==== |
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old isa aui ethernet cards can be used with lasers to make super cheap optical networks as well. These lasers are common and I can't imagine them being much worse than LED's for safety. [[User:AaronPeterson|AaronPeterson]] 17:34, 23 December 2007 (EST) |
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[[Category:Hardware ideas]] |
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[[Category:Software ideas]] |
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[[Category:Network]] |
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[[Category:Internet]] |
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[[category:peripherals]] |
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Revision as of 20:07, 16 December 2008
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