Re: [gentoo-user] looking for wireless technology
On Saturday 12 November 2005 23:51, Willie Wong wrote: On Sun, Nov 13, 2005 at 11:02:09AM +0600, El Nino wrote: i have a 128kbps Internet connection to my home now i want give access to my college friends to it. (i already have two running squid+firewall gentoo servers) I'm looking for wireless technology to do this. all friends are within 1km. A noble pursuit, but I doubt it could be done easily... AFAIK IEEE802.11 is mostly reliable only for clients within 100 meters. Unless you live on the top of a hill with wide open space all around you for kilometers, I doubt you'd get coverage all the way out of 1 kilometer. And if someone happened to be using wireless on neighboring frequency bands to the one you are using, and if that someone happened to be physically closer to your friend than you are, there's almost no hope in establishing a connection... Actually, my brother works for a company in Virginia that is doing wireless ethernet over distances this great or greater. I doubt the technology they use will be cheap enough for this application, though. Of course, you could mean wireless other than 802.11, but I don't think IP over carrier pigeons or bongo drums[1] would do you much good either. If you have line-of-sight, you might be able to make do with a pair of directional antennae set up in the right way, and you might need a way of increasing the power output of the antennae. Any such modifications, however, is surely ILLEGAL in most civilized municipalities. The long-range wireless guys who have been doing stuff like this all have ham licenses, and are allowed quite a bit more power from their devices then us lowly consumers Best W can anyone give me a solution to do this? all advices are warmly welcome... [1] http://arstechnica.com/news.ars/post/20030929-2886.html -- This one's a bitummm...graphic? Lagrangian Mechanics with Differential Equations is like masturbating. You do what works and what makes you feel good. ~DeathMech, Some Student. P-town PHY 205 Sortir en Pantoufles: up 21:59 -- John Jolet Your On-Demand IT Department 512-762-0729 www.jolet.net [EMAIL PROTECTED] -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] looking for wireless technology
On Nov 13, 2005, at 5:51 am, Willie Wong wrote: If you have line-of-sight, you might be able to make do with a pair of directional antennae set up in the right way, and you might need a way of increasing the power output of the antennae. Any such modifications, however, is surely ILLEGAL in most civilized municipalities. The long-range wireless guys who have been doing stuff like this all have ham licenses, and are allowed quite a bit more power from their devices then us lowly consumers I think you're mistaken here. 802.11 is on an unregulated part of the frequency spectrum, so ham radio operators have no more rights when operating in it than the rest of us. 802.11 is perfectly achievable over distances of a kilometer, providing line of sight is available, and legally. The requirement is not to emit more than a certain signal strength (about 18dB or 20dB, I think) but signal strength is a product of transmitter power and amplification caused by the aerial. A very directional aerial amplifies the signal lots, but if you combine this with a low-power transmitter then you can still creep in under the legal signal strength. One might ask, but if I'm transmitting 20dB with a low-power directional aerial, that gives me the same range as 20dB using a non-directional aerial (like the rubber-jacketed kind that are supplied with wireless cards) at high-power but this doesn't take into account receive attenuation. The directional aerial at the OTHER end will pick up the signal more clearly - it's listening in only one direction and effectively amplifies that signal for the receiver. Instructions for building directional aerials are posted widely on the net, and the OP will be able to find them easily with a bit of searching (check out the Seattle Wireless Guerilla Wireless websites) but it's harder to find wireless cards that will transmit at low enough power to make them (legally) useful. Last time I checked I could only find the expensive Cisco Aeronet (??) kit to be documented as being used in this way; I suspect there's not much available in Linux-compatible 54G kit out there. When I looked at doing this line-of-sight was a bigger hurdle. Stroller. -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] looking for wireless technology
On Sun, Nov 13, 2005 at 03:18:16PM +, Stroller wrote: On Nov 13, 2005, at 5:51 am, Willie Wong wrote: If you have line-of-sight, you might be able to make do with a pair of directional antennae set up in the right way, and you might need a way of increasing the power output of the antennae. Any such modifications, however, is surely ILLEGAL in most civilized municipalities. The long-range wireless guys who have been doing stuff like this all have ham licenses, and are allowed quite a bit more power from their devices then us lowly consumers I think you're mistaken here. 802.11 is on an unregulated part of the frequency spectrum, so ham radio operators have no more rights when operating in it than the rest of us. My bad. Somehow I thought 802.11 is regulated, which, of course, on hindsight, is completely stupid. Barring that, there are still transmission power limits by local governments. 802.11 is perfectly achievable over distances of a kilometer, providing line of sight is available, and legally. The requirement is not to emit more than a certain signal strength (about 18dB or 20dB, I think) but Hum, you are probably more knowledgeable then I am, but I am sure there are both absolute power limits AND power density limits imposed by most governments? http://www.oreilly.com/catalog/802dot11/chapter/ch15.html of course, one presumably won't go hacking the transmitter to output more power than was set at the factory, which is probably close to the legal limit anyway. So one does need to only worry about power density. signal strength is a product of transmitter power and amplification caused by the aerial. A very directional aerial amplifies the signal lots, but if you combine this with a low-power transmitter then you can still creep in under the legal signal strength. If, you are in Europe, for example, to get reliable 1km coverage from the 66mW legal limit on the transmitting device, some simple math (or a quick search on the internet-what I did) says you need a 10-12dB gain from your antenna. You probably need a good Yagi or Parabolic for your antenna to get the required gain. And I would _hate_ to be the one having to set up the line-of-sight link between two parabolic antennae W -- (aikamuotojen k?ytt? aikamatkustuksessa) You can arrive (mayan arivan on-when) for any sitting you like without prior (late fore-when) reservation because you can book retrospectively, as it were when you return to your own time. (you can have on-book haventa forewhen presooning returningwenta retrohome.) Sortir en Pantoufles: up 1 day, 11:03 -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] looking for wireless technology
On Sun, 13 Nov 2005 00:51:12 -0500 Willie Wong wrote: On Sun, Nov 13, 2005 at 11:02:09AM +0600, El Nino wrote: i have a 128kbps Internet connection to my home now i want give access to my college friends to it. (i already have two running squid+firewall gentoo servers) I'm looking for wireless technology to do this. all friends are within 1km. A noble pursuit, but I doubt it could be done easily... AFAIK IEEE802.11 is mostly reliable only for clients within 100 meters. Unless you live on the top of a hill with wide open space all around you for kilometers, I doubt you'd get coverage all the way out of 1 kilometer. And if someone happened to be using wireless on neighboring frequency bands to the one you are using, and if that someone happened to be physically closer to your friend than you are, there's almost no hope in establishing a connection... What bollocks. 802.11 is capable of 5 km at least with a decent card and directional aerials. Directional aerials can be built from quite cheap materials like woks and other asian food implements, or you can buy commercial directional aerials. examples: http://homepages.paradise.net.nz/g.mckenzie/Radio%20Dish/Radio%20aerial.htm http://www.usbwifi.orcon.net.nz/ -- Nick Rout [EMAIL PROTECTED] -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] looking for wireless technology
Nick Rout wrote: What bollocks. 802.11 is capable of 5 km at least with a decent card and directional aerials. Directional aerials can be built from quite cheap materials like woks and other asian food implements, or you can buy commercial directional aerials. The world record is set at ~125 miles (~200km) using an un-amplified signal: http://www.engadget.com/entry/1234000970052590/ http://wireless.weblogsinc.com/entry/1234000407052562/ http://www.wifiworldrecord.com/ -- Jonathan Wright ~ [EMAIL PROTECTED] ~ www.djnauk.co.uk -- 2.6.13-gentoo-r3-djnauk-b2 AMD Athlon(tm) XP 2100+ up 7 days, 19 min, 3 users, load average: 0.96, 0.97, 0.75 -- cat /dev/random (because u never know, u may see something u like) -- People sometimes think I'm gay because I once played a gay in a movie. It's funny. Audiences don't think you're a murderer if you play a murderer, but they do think you're gay if you play a gay. ~ Perry King -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] looking for wireless technology
On Sun, Nov 13, 2005 at 11:02:09AM +0600, El Nino wrote: i have a 128kbps Internet connection to my home now i want give access to my college friends to it. (i already have two running squid+firewall gentoo servers) I'm looking for wireless technology to do this. all friends are within 1km. A noble pursuit, but I doubt it could be done easily... AFAIK IEEE802.11 is mostly reliable only for clients within 100 meters. Unless you live on the top of a hill with wide open space all around you for kilometers, I doubt you'd get coverage all the way out of 1 kilometer. And if someone happened to be using wireless on neighboring frequency bands to the one you are using, and if that someone happened to be physically closer to your friend than you are, there's almost no hope in establishing a connection... Of course, you could mean wireless other than 802.11, but I don't think IP over carrier pigeons or bongo drums[1] would do you much good either. If you have line-of-sight, you might be able to make do with a pair of directional antennae set up in the right way, and you might need a way of increasing the power output of the antennae. Any such modifications, however, is surely ILLEGAL in most civilized municipalities. The long-range wireless guys who have been doing stuff like this all have ham licenses, and are allowed quite a bit more power from their devices then us lowly consumers Best W can anyone give me a solution to do this? all advices are warmly welcome... [1] http://arstechnica.com/news.ars/post/20030929-2886.html -- This one's a bitummm...graphic? Lagrangian Mechanics with Differential Equations is like masturbating. You do what works and what makes you feel good. ~DeathMech, Some Student. P-town PHY 205 Sortir en Pantoufles: up 21:59 -- gentoo-user@gentoo.org mailing list
