How far does your laptop WiFi reach? Do you get 10, maybe 20 meters from your base station before the signal degrades? Wouldn't it be nice to get 500 meters? Or what about a whole kilometer, and that's with a stock laptop, not one modified with a directional antenna like the joe-cool BottleNet?
You soon shall with One Laptop Per Child. With their claim to be the first implementation of the emerging 802.11s standard, they are making Superman-sized leaps in connectivity using Marvell wireless firmware with full mesh functionality on the Children's Machine XO.
As Walter Bender reports in this week's OLPC Community News, James Cameron's continued wireless distance testing in rural Outback Australia with OLPC XO-1's is producing impressive WiFi connectivity results:
I've just completed a rural range test in ad-hoc mode, using two laptops, at a height above ground of 1.5 metres, over 1.26 kilometers line of sight.
These results are much better than the previous managed mode results, against my test access point. I suspect my access point lowered the previous results.
Both BTest-1 units were running OS build 225 with Q2B16 and Q2B19 firmware. One unit was placed at one end of a straight dirt road, 1.5m above ground, in open position with ears up. The second unit was walked down the test range.
At distance intervals, performance was analysed using iwconfig, ping -i 0.1, and arecord piped to aplay over ssh to listen to the wind on the microphone of the base unit at 8000 Hz. The results from on the second unit are:
- 200m, signal -72 dBm, noise -85 dBm, rate 11 Mb/s, all okay,
- 400m, signal -77 dBm, noise -89 dBm, rate 5.5 Mb/s, all okay,
- 600m, signal -84 dBm, noise -89 dBm, rate 1 Mb/s, all okay,
- 950m, signal -84 dBm, noise -85 dBm, rate 1 Mb/s, some ping loss,
- 1260m, signal -87 dBm, noise -89 dBm, rate 1 Mb/s, more ping loss.
Or as James Cameron succinctly concludes:
I'm sure these units would perform very well if stuck on a tower ... but I agree that isn't their purpose.Not their main purpose, but at a kilometer of connectivity per laptop, they will facilitate all kinds of purposes!