RONJA

User Controlled Technology Optical Datalink

Karel 'Clock' Kulhavy

1998: Experiments with IrDA 115.200 Baud

2005:

10Mbps

1.4km range

Full duplex

Red or infrared

User Controlled Technology (UCT)

A project of Twibright Labs

Range

Transmission by ordinary (infra)red light

Rain, snow OK

1.4km range @4km visibility

Stable, given by white noise from Sun

Transmitter

LED from car brake light (cost 1$)

13cm lens (3$)

17mW of red light

Unconditionally eye safe

4m spot @ 1km

Material and time cost

100$ for one device total material cost

Most expensive components:

Electronic 1.20$ (16MHz crystal oscillator)

Mechanic 4$ (smoke pipe 1 meter)

Optic 2-15$ (130mm loupe)

70 hours building time for average Joe

Much less hours with careful planning

Most time spend on searching for tools and parts

Advantages

No interference

No spectrum regulation

No electrosmog

Difficult eavesdropping

Smooth throughput

Full duplex

No packetloss

Disadvantages

Dropouts on fog (no problem for ordinary usage)

Mount requirements

PtP topology only

Mechanics: 10-20kg

Support

"I have populated more than 20 Twisters and I have to say all worked on the first try." (Petr Seliger, Ronja mailing list)

Adhere to the guide -> works on the 1st try

Doesn't work -> bug -> report to Ronja ML

Bugs have priority to features

“Ronja is a really robust device. It runs [on our 800m link] even if you cover 95% of the lens with a paper. That will be useful when a fog comes.”	http://bakulak.czfree.net/news.html

Can't wait even in thick fog?

Special SW requirements

Immediate dropout detection

Ronja + WiFi backup

Modularity

3 different models (AUI, RJ45, red, infrared)

6 electronic modules (2RX, 2TX, 2interf.)

7 mechanic modules (6 consoles + 1 holder)

2 optical modules (90mm and 130mm heads)

1 Ronja = RX+TX+interface+optical head+holder+console+cabling

1 link=2 Ronjas

PC or switch (managed)

Mechanical mounting

Holder with fine and rough alignment

5 types of console

Chimney

Parallel

Perpendicular

Mast

Corner

Boards

Twister, TX

Download *.zip, e-mail to fabhouse, get boards by post.

Standardized format accepted by all fabhouses

No thinking required to order

SMD miniaturization

Already done on another Twibright Labs project – I2C2P

The same toolchain as Ronja

Easily solderable by layman with $20 soldering gun

Cheaper, faster to build than TMD

Freedom

DIY for laymen

Step-by-step guide

Minimum skills required

Various operations can be ordered

Complete source codes online under GPL

Only free software tools used on development

Anyone can do his own fork if he doesn't like it

Advanced free software tools

3D modelling BRL-CAD

2D modelling QCad

Schematics, boards: gEDA

250MB of source tree

2 hours make time

Installations

102 registered installations

57 km total length

9 different countries

Installation peculiarities

1.7km longest (Poruba, CZ)

1.3/0.4km analogue retranslation (Běhařovice, CZ)

990m student dormitory, 1000 students (SK)

Prague: 21 links in one community network (CZFree.NET)

21 installations in Prague CZFree.NET

Continuous community network

Attempt for independent last-mile infrastructure

Covers whole Prague

Mostly WiFi

Ronja solves interference

Postindustrial nature

Widespread availability of raw material resources

Byproduct of globalized consumerism

Ronja can exploit IKEA EMU 0507/0518 box

Drilling templates speed up manufacture

“It's not anymore about the product. Now it's about the attitude.” (Stacy Peralta, Dogtown and Z-Boys, 2001)

Lucasvo holding prototype of bugfixed parallel console

Social aspects of UCT

Age or education show not to be important for users or developer (I got no EE school)

Breaks barriers

Lot of fun with friends in the garage

Modern autistic computer-addict lifts his ass from the computer and becomes a human again

Consumption and power replaced by creativity

Humanistic aspects of UCT

No more automaton conformist consumerism

Both user and developer:

in control of the product

treated as fellow human, not exploited

individuality is respected (mailing list)

More effective learning of technical subject than in school

Project bottleneck

90% of delopment cost is time

Est. 80% done by me, 20% by other developers

Time dedication of main developer (=me)

Currently ~1 hour/day

8 hours/day would be optimal

New developers slow in beginning (low usability of free software tools, lack of experience)

Project future

3.0km range with Fogtown TX (right)

100Mbps

2$ cheap laser pointer measured BW of 1GHz

Ideal for 1Gbps!

Welding the Fogtown prototype

TheEnd

References

http://ronja.twibright.com Ronja website

K.Banke, C. Houghton: A Cheap and Simple Experimental Wide-Band Laser Link,http://www.earthsignals.com/add_CGC/hr/Wb_Laser.doc

http://twibright.com Twibright Labs website

What about historic urban zones?

Ronja can be concealed

Behind a window

Behind a chimney

Ronja is smaller than a satellite dish

How to make multipoint with Ronja?

More Ronjas have to be installed in one place

No interference occurs

Definition of UCT

UCT is Free Software concept generalized to technology

4 essential freedoms (taken from Stallman):

The freedom to use the device as you wish

The freedom to study the source documents and change it to implement what you wish

The freedom to manufacture and sell the device

The freedom to publish modified versions

Ronja Optical Datalink

2005-06-04T16:40:55