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Long-Range Networking
ink and several others sent in the latest Cringely column where he discusses creating a long-range 802.11b network using high-tech tools like a telescope and bribery. Sean Clifford sent in guide to creating your own long-range antenna: "Have some old PrimeStar hardware laying around? Do something useful with it by turning it into an IEEE 802.11 wireless networking antenna. This electrical engineering professor uses an Airport, but any access point should work fine." If you're at all interested in this sort of stuff, get involved with one of the community wireless networks springing up.
Apropos to community networks, I'd like to make a shameless plug for a GPL-compatible open source gateway and settlement system, downloadable from ftp://ftp.lanroamer.net/pub/lanroamer. The backend software will also be released under GPL later this weekend. There is obviously a business behind it, but the software and the ideas are relevant to this article in their own right. The basic idea is that whoever puts up an access point gets free use of the everyone else's access points and a significant share of share of the revenues from paying customers (expected cost to paying customers: $20-$25/month). We are in the process of setting up a sourceforge area for the software as well. Finally, if you're curious about future development direction, you might want to check out the current wish list, although completely different additions to this list and, better yet, contributed code are welcome.
At first when I read the summary of the article, I was thinking that he was going to somehow use those telescopes to actually DO the networking instead of just using them to find a house.
:)
In fact, I kept thinking this beyond the point where he was talking about street lights and stop lights.
I wonder, how feasible could such a system be? If I had a high powered light bulb (or some other convienent light source) that could switch on and off very rapidly, then at the other end of the "network" have a telescope with a CCD camera watching the light, as long as the telescope never moved, data could be sent at a rate equal to the speed at which the light could be toggled.
I can see a great number of potential obstacles to this which would make it difficult to use in a production environment. But it would be a cool hack nevertheless.
-Restil
Play with my webcams and lights here
Here is a Low Cost Wireless Network How-To.
It covers the technical details that the other wireless networking sites miss. It has amplifier ideas and schematics and external antenna mods using old MMDS dishes. It even has CGIs for preforming wireless link analysis.
Airport is ideal for this sort of project - the base stations are relatively inexpensive, and they can be easily configured without a Mac - one fellow wrote a Java-based configurator app. They also work with pretty much any wireless card out there, AFAIK. I also use a Linksys with mine for one of my Wintel boxes.
I took my Airport and added the Lucent range extender antenna (about $60), and simply dremeled my base station to accept the antenna mount. I've been using it for about a year and a half now, and it gives me an effective range of about a quarter mile (it helps that I mounted the whole rig on an outer wall upstairs in my house) when used with my iBook.
To go much farther you either need more power (which may tick off our friends at the FCC) or directional antennas, like Cringely used, with clear line-of-sight. You're subject to all limitations of the 2.4 GHz band, though, and a lot of current cordless phones run in that range - it can mess up 802.11 signals somewhat.
I stick to 900 MHz digital phones partly for that reason.
- -Josh Turiel
-- Josh Turiel
"2. Do not eat iPod Shuffle."
Oh man Ham radio operators have been using soup cans and other cans for feedhorns before commercial "experts" came in.
yes ther eis a reason for having everything over-engineered as you stated above.. It's for efficency.. This guy couldnt care less as long as he got 20Db gain... a real ham with a better source of soup cans and a 5 foot surplus spun aluminum dish could get 50-60db gain out of a properly sized soupcan.
Go buy a ARRL handbook, and the ARRL antenna handbook. learn about Dish antennas and how to do it in your garage as good as a multi-jillion dollar company with computer machined parts.
Do not look at laser with remaining good eye.
Tim Pozar's page The FCC's Part15 Rules and Regulation and 802.11b emissions in the ISM 2.4GHz Band discusses this and has links to the regulations and other useful references. Look for the section titled "Fixed, point-to-point paths and get even more power."