Lee, up here in NoCat land (West Sonoma county), we're in a bit of a different situation geographically in that we're not residental but rural. However, we had the same goals when we started building a free wireless network and then built an internet co-op on top of that network.
I can tell you what hasn't worked: We made the mistake of building relay nodes with multiple radios in the same box. That doesn't work. The higher power the card, the more interference, and at some nodes we had two 200mw cards in the same box. That doesn't work. If you need multiple radios at one location, you need to physically separate the radios by at least 4 feet. If you have external directional antennas, those should be separated by as much space as you can spare LMR-400 cable. We've also made the mistake of oversubscribing client radios to a single access point, and the fact that all of these shots are directional antennas pointed at a sector just makes the progblem worse. Finally, we've really oversubscribed our single DSL line. I was a board member of the co-op (http://www.wscicc.org) and gave up for various personal reasons, but also because I couldn't convince anyone else that 384k up is insufficient for the number of users we had. As far as the backhaul goes, my idea was this: Soekris Net4521 Prism-based card to serve as 802.11b access point Atheros-based MiniPCI card (the only kind with pigtail connector) to serve as 802.11a backhaul Pebble running on the soekris - latest pebble has madwifi drivers for the Atheros card Costwise here, you're talking about $260 for the Soekris, 30-100 for the Prism card depending on what milliwattage you want, and 70-100 for the Atheros card, plus antennas and cable. So one of these is going to run around $500. I'm pretty sure that's cheaper than Canopy, Trango or the others. Then again, if these Proxim 802.11a access points can be made to bridge, you could do something super cheap: Linksys WRT54G to serve as the 802.11b/g AP - you could use the Sveasoft firmware and run WDS between multiple Linksys units to expand your range without running DSL Proxim 802.11a bridge for backhaul Antennas That should get your cost down significantly. We haven't tested either of these configurations but want to, as we now have some donated 5ghz antennas we can use for testing, and a couple of the WRT54G units, and I'm going to get some of those Proxim units too if they're still available. Roger Weeks --- Lee Barken <[EMAIL PROTECTED]> wrote: > Let me see if I can ask our question another way-- > > Our goal is to provide free wireless access to residential > neighborhoods > in San Diego (and hopefully provide a model for other cities). Our > first > "node" was easy-- we ran a DSL line (with the blessing of our > ISP, Speakeasy) to a nice omni antenna on the roof and let the > neighborhood play. To expand the network, we went to another nearby > rooftop and used a combination of an ethernet bridge feeding directly > to > an additional AP. We followed this pattern for a few more locations > with > several other locations on the drawing board. (Think hub and spoke). > > Sounds great, right? > > Well, the problem isn't the client access method (802.11b to the > clients). > The problem is the backhaul (in our case, also 802.11b). Given the > enormous "clutter" in the 2.4GHz band, we're finding it increasingly > difficult to build reliable links between our rooftops. > > What next? > > We're aware of many commercially available solutions-- Alvarion, > Motorola > (Canopy), Trango and many others produce quality products that work > well > in enterprise deployments. Unfortunately, our primary consideration > is > *cost*. Oh, and also, we're geeks, so um... we like to build stuff > (long > live Soekris!) :-) On the other hand, we're also concerned about > reliability (a solution that costs 5 dollars, but needs to be > rebooted > every 15 minutes doesn't help us much either). > > Collectively, we're asking for creative ideas for backhaul options. > What > works? What doesn't? What can we learn from each other? > > We are considering: > > - Alternate polarization for our backhaul antennas (horizontal? > circular?) > - Using 802.11a or other 5GHz options > - Using 802.11b, but adding amps and "blasting through" > - Using FHSS systems in 2.4GHz (such as breezenet pro.11 or raylink) > - WiMax (down the road?) > > Any thoughts? Ideas? > > BTW- Mike and I will be at the Broadband Wireless World (San Diego) > conference tomorrow... If you happen to be attending, please contact > me > offlist and maybe we can meet up? :-) > > Thanks, > -Lee > San Diego Wireless Users Group > http://www.sdwug.org > http://www.socalfreenet.org > > > -- > general wireless list, a bawug thing <http://www.bawug.org/> > [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless __________________________________ Do you Yahoo!? Yahoo! Mail SpamGuard - Read only the mail you want. http://antispam.yahoo.com/tools -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
