A key point in building a CommunityNetwork is to make our members extend the network in order to use it. This will help us avoid the "tragedy of the commons" and continue to provide access which is useful to everyone. Right now there is a shortage of known good, and free, ways to do this. SamChurchill has compiled a list of applications and hardware which do all or part of this job.
Mesh Networks http://www.meshnetworks.com/ will use a PCMCIA cards http://www.wirelessweek.com/index.asp?layout=story&articleid=CA154415&spaced to connect to another device, such as a Compaq iPAQ handheld, enabling the latter to be used for voice over Internet protocol, data and even video. Working together, the devices route IP traffic to its intended destination.
Radiant Networks http://www.radiantnetworks.com/ has a mesh architecture which links around obstacles by branching through the neighborhood. http://www.commsdesign.com/features/OEG20010802S0017 It works in congested cities and suburban/rural environments.
Bob Cringely http://www.pbs.org/cringely/pulpit/pulpit20010712.html points out that http://www.nwr.nokia.com/ Nokia has a rooftop solution that finds its own route. Nokia is working with the IEEE 802.16 committee on http://wirelessman.org/tg4/contrib/802164c-01_39.pdf 5.8 Ghz Mesh networks.
Wave Wireless http://www.wavewireless.com/products/mapperindexzzz.cfm?ID=p18 devices act as both the Customer Premises Equipment (CPE) and a repeater for other devices in the area. Non-Line-Of-Sight happens through dynamic routing. http://www.shorecliffcommunications.com/magazine/volume.asp?vol=19&story=177 Smart antennas may aid NLOS.
e-tenna http://www.etenna.com/flexscan.html can be self-installing and self-aligning. http://www.beamreachnetworks.com/brn/index.html Beam Reach says adaptive beamforming can get 20 dB gain over a typical ODFM system.
Navini http://www.navini.com/pages/solutions/solution.htm promises broadband at half the cost of DSL. Navini http://www.broadbandweek.com/news/010709/print/010709_wireless_ant.htm combines adaptive phased array smart antenna technology with digital beam forming and http://www.broadbandgateways.com/news/NewsReleases/scrollnavini.htm 802.11b in the home.
Portland State is researching https://www.fastlane.nsf.gov/servlet/showaward?award=0196043 in Wireless Ad Hoc Networks in research papers http://www.ics.uci.edu/~atm/adhoc/paper-collection/papers.html
Adoptive beamforming http://www.3com.com/other/pdfs/infra/corpinfo/en_US/50306401.pdf and http://mevard.www.media.mit.edu/projects/Davis-Net/ ad-hoc networks of 802.11 cells may create city-wide networks competitive to 3G cellular.
By combining OFDM, spatial diversity (two antennas), Adaptive beam forming (phased array antennas) and frequency or time division multiplexing with QOS (why not), some wireless startups believe you can deliver non-line of sight wireless cheaper and faster than DSL and Cable Modems. I want to believe them.