So Cal Free Net.org

On Saturday, we did a site survey at a new location, the Hourglass Park Apartments at 9505 Gold Coast Drive, San Diego 92126.

The highlights of the survey are:

• Great signal propagation through the buildings. We were able to receive signals clear through the otherside of a complete building of units. This dramatically lowers the cost of deployment.
• Good roof access. The rooftops are flat and safe to work on. The only thing needed is a 24 ft ladder.
• Easy access to power. Existing open 'drainpipe' conduits are available to run Cat-5 cable from power in the utility closet on each building.
• Good community benefit. Apart from the benefits to the existing residents, nearby facing apartments will get good coverage too. Most fun, however, is the excellent coverage at the playground down the street. (Though not sitting in the bus stop shelter due to the metal grill wall - -65dBi outside the shelter, -85dBi inside, 6 inches away!)
• Bandwidth is readily available. As we discovered, both Time Warner cable internet and DSL are available and, judging by the 20 or so APs we found, many tenants already using broadband. This will save them $25-50 month when installed.
• There's almost 20 APs already in the complex. Fortunately most of them are on channel 6, with just a few on channel 1 or 11. For those interested in such things, about 1/2 had WEP enabled (including 3 2Wire APs) and, unusually, most did not have the default SSID. Perhaps there's a local geek tenant who helps with such things? We should be so lucky!

Our tentative solution is to mount four APs as shown by the red dots on the map. The bottom left AP will be the master AP equipped with an 802.11a omni antenna as well as a local 802.11b AP and downtilt omni. The others will have an 802.11a directional antenna to use for a backhaul and a local 802.11b AP.

Our cost guesstimate is about $1000 per AP (for a Metrix box, added 802.11a radio, 802.11a (or parabolic) and 802.11b antennas, tripod, cables, cat-5 cable etc). This is gear we've installed several times now, so we expect it to be a predictable installation (I'm learning never to say easy!).

We'll tie it all together with another box acting as the gateway and traffic shaper. We may also put a squid proxy cache there, to better utilize bandwidth. The two main contenders are a Soekris box running m0n0wall using its 'Wonder Shaper' settings and a separate squid box for caching, or a 4801 Soekris box with a hard disk running Mikrotik which has caching built-in.

At some point, we'd really like to move away from using Pebble in the nodes due to the relative complexities of configuration (think Linux vs web-browser), but although some great 802.11b radios exist, we haven't found an affordable (indoor or outdoor) 802.11a client and/or AP we can use. Hopefully soon...