Hello my name is Karel Kulhavy and I'll talk about my project Ronja. Ronja is
an open source optical wireless point to point link for Ethernet network.

I have brought some pieces of the device. Please circulate them in the
audience.

--- Slide Technical data ----

Ronja differs from the familiar WiFi in the carrier frequency - 480,000 GHz
which is red light, or 340,000 GHz, which is infrared light. Ronja can be
plugged into a network card or a switch, runs at 10Mbps full duplex and doesn't
degrade under 100% load. The typical bit error rate is better than 1 bit in a
billion and ping round trip less than 1 millisecond.  Ronja has a range of 1.4
km. 

--- Slide Features ---

Unlike WiFi, Ronja can be chained practically indefinitely without running into
problems with packetloss or delay. We tried chaining two Ronjas on total
distance of 500 meters and watched a DVD rip movie through Samba in real time.
We didn't notice any glitch. We also tried to use HTTP, ssh and FTP when Ronja
was 100% loaded for 8 hours when backing up a 36GB hard disk. We didn't notice
any slowdown.

However, Ronja fails in a dense fog and requires a stable mount like a wall,
railing or mast.

--- Slide a link consists of... ---

One link consists of four magnifying glasses, four smoke pipes, various steel
parts, and 426 inexpensive electronic components. The most expensive electronic
part, a crystal oscillator, costs 1 dollar 20 cents. One link requires material
worth 300 dollars and 70 hours of time.

--- Slide User friendly ---

The parts and construction methods are selected to be Do-It-Yourself friendly.
No special purpose integrated circuits are used, the most sophisticated chip
used is a 12-bit binary counter. The end user doesn't need to understand
electronics. He downloads a file from the Internet, sends it to any printed
circuit board factory and gets a board through the post. Detailed, easy to
understand instructions on the website lead him to an installed wireless link
that should work on the first try.

--- Slide History etc. ---

The development started in 1998. First a 115kbps device was developed. On
Christmas 2001, a 10Mbps version was released, becoming the fastest of this
kind in the world. Subsequently, Ronja had been slashdotted twice. Ronja has
been installed in 153 registered installations worldwide. The closest one is in
Lausanne, Switzerland. In Slovakia, a student dormitory with 1000 students was
connected to the Internet with a Ronja over 900 meters.

Ronja has been published on an IEEE conference and North Carolina State
University has developed an experimental underwater link based on Ronja.

--- Slide Free Software ---

Only free software is used for Ronja development. Qcad and BRL-CAD are used for
the mechanics. Gschem, PCB, Gerbv and Gnucap cater for electronic design and
simulation. Gnuplot and GNU R process physical data. Gimp, Sodipodi, Autotrace
and ImageMagick are used for graphical works. GNU Make, Subversion and Rsync
build and archive the source and synchronize the website content.

--- Slide Continuing Development ---

The ongoing development focuses on bugfixes and releases of unreleased parts of
design.  After that I would like to increase the range, and then increase the
speed to 100Mbps and 1Gbps.

--- Slide Thank You For Attention ---

Thank you for your attention. Now I am prepared to answer questions.