Sharing wireless internet access wirelessly

April 17, 2005 8:35 AM

My sister lives in a small town in NH that started offering free wireless access in the center of town. I'd like for her to be able to connect to the internet from her house, which is about .5 miles away from the antenna but with tall buildings (church steeples) in between. She has a desktop, her husband has a Centrino-equipped laptop, and I visit with a 802.11-able laptop. My brother-and-law and I are thinking of building a cantenna or the like and mounting it on the roof . But what do we attach the antenna to? All the routers/"access points" I've looked at so far assume a cable (ethernet) connection as input signal which is then output as wireless or ethernet or both. But we want to both receive and dispense wireless. I know there are "repeaters" that can do this but all the affordable ones I've studied only output using proprietary protocols, not 802.11(g), which would require buying proprietary equipment for all the computers in question. Any inexpensive solutions?
posted by TimeFactor to computers & internet (8 comments total)

High gain wireless antenna made from a cheap Chinese cooking utensil here.
posted by fourstar at 9:43 AM on April 17, 2005

... and I don't think what you are asking is possible without buying a router/access point. But you can pick one up on eBay cheap -- as in less than the cost of paying for Internet for one month.
posted by fourstar at 9:48 AM on April 17, 2005

if you have an old computer you can install linux and do pretty much anything wrt routing as long as buy enough network cards. but that's a lot of time and work.

i know 802 devices can work in a kind of peer-to-peer mode. can you exploit that somehow?

are you sure existing routers/access points won't do it? you need the nat+dhcp to work with the "external conxn" as a wireless rather than a cable conexn, but that's just a software limitation, i would guess. what's the "range extender mode" provided by this belkin router? that sounds like the kind of thing you want.
posted by andrew cooke at 10:02 AM on April 17, 2005

Actually...

You can buy a D-Link Wireless router or hub and configure it in "Bridge" mode. This reverses the direction of the traffic so that it takes the signal in via the wireless antenna and out the ethernet port. Then run that into a wireless router or another access point that's configured on a different channel with an antenna inside your house, and voila, you've got a relay.
posted by SpecialK at 11:13 AM on April 17, 2005

fourstar: The Chinese restaurant my sister and I met in last night to discuss this project had one of those strainers hanging from the kitchen wall. I was tempted to borrow it. But we have the antenna phase of the project worked out: first a parabolic cylinder because a working prototype can be made in a few minutes, then a downspout slotted waveguide if we need more gain.

andrew: are you sure existing routers/access points won't do it? you need the nat+dhcp to work with the "external conxn" as a wireless rather than a cable conexn, but that's just a software limitation, i would guess.

It seems like a software limitation to me as well, unless the hardware is specifically designed for limitation, which the repeaters I've looked at seem to be. I think I'll just have to buy something like the router you linked to, try it out, and return it if it can't do what I want. I've built Linux firewall/router boxes before (and have one in storage) but I'm just not interested in rolling-my-own for the sake of rolling-my-own anymore and would rather limit my tinkering to building the hardware (antenna).
posted by TimeFactor at 11:30 AM on April 17, 2005

SpecialK: sorry, I didn't see that you'd responded. Great! andrew's link suggests the Belkin router has a similar bridge mode but it isn't clear. But now that I know that such a thing exists I'm ready to proceed.
posted by TimeFactor at 11:34 AM on April 17, 2005

Inicdentally, Cringely's article from this week is about exactly this problem.
posted by Caviar at 2:26 PM on April 17, 2005

The Linksys WRT54G can take an external antenna, and be set up in bridge mode with third-party firmware.
posted by RikiTikiTavi at 3:11 PM on April 17, 2005