Every day, I have 30 minutes of time to waste on a train, going from Haarlem to Amsterdam or vice versa, a 15-minute trip. Sometimes, I open up a laptop to write a few more lines of code or play some gridwars or whatever. Most of the times, I’ll also have a look at the wireless networks around. It always surprises me how many there are these days.

So the past few days I’ve been lugging a MacBook Pro around, and I’ve noticed it’s very good at sniffing out wireless beacons. My TiBook will usually only show only one or two networks where the macbook will pick up on 6 or 7.

I’ve described two dots. Now let’s connect them.

I figured it was time to run KisMAC on the macbook while on the train from Amsterdam to Haarlem. I’ve actually done this before when I was still using a PowerBook G3 with a PCMCIA wifi card, but didn’t really pick up on anything. I think I found about 5 networks that day. This time was a little different.

Some stats:
Between Amsterdam Central Station and Haarlem, there are at least 110 wireless networks, reachable from inside a moving train. Of those, 33 are on channel 1, and 38 are on channel 11. 17 are on channel 6, 8 are on channel 13, 7 on channel 7, 6 on channel 3 and one on channel 8. The other channels don’t see any action. 17 networks use WPA encryption. 37 use WEP. The remainder is unencrypted. 30 seem to be set to their defaults.

This was with an active scan, as KisMAC does not yet support passive scanning on intel macs. That means hidden networks do not show. I think I might repeat this experiment later with a non-pro MacBook. It has even better wifi reception thanks to its entirely non-metal case.

Scan results as a Netstumbler text file.

Update:

Tried it on a MacBook non-pro too. As I thought, it does slightly better: it comes up with 286 networks. Contrast that to my TiBook which picks up on a whopping 15 networks.