mensi.ch

I recently had the chance to play around with a LaserBit Wireless Cable. It is very easy to use: I just acts like a straight LAN cable and comes with RJ45 connectors. Setting it up is pretty simple in theory: fix each transceiver on something and point them at each other; alignment however is quite tricky over large distances because you can’t actually see the laser; it’s IR. We had quite some trouble with our ~600m setup but finally managed to establish a stable link. It only held for one day though as one end was attached to a large tent; obviously not the best thing but our only option. We previously tried to use 2.4Ghz helix antennas (~14db gain) and standard WLAN, but it failed miserably at about 200m due to several obstacles and a little hill.

The whole setup: (internet access for a camp)

We got ADSL from a nearby farm, attached an ADSL modem and a WRT54GL accesspoint which provided coverage for an AP in client mode attached to one end of the Wireless Cable. The other end was at the top of a tent, attached to another WRT54GL, which provided covergage for the camp. Another WRT widened the range (per WDS) and had a printer attached.

It was an interesting project, however it was never used at its intended purpose; sometimes the laser had to be realigned, sometimes the ADSL connection dropped (the farm itself was quite abroad, so the line quality wasn’t that great…)