Welcome to Etherpad!

This pad text is synchronized as you type, so that everyone viewing this page sees the same text. This allows you to collaborate seamlessly on documents!

Get involved with Etherpad at http://etherpad.org
Wirelessness
( proposed by Roel Roscam Abbing + Dennis de Bel + Alejo Duque )

When speaking about invisible technologies radio is perhaps both the most invisible and yet the most present. At any given moment the air is filled signals ranging from cell phone packets, the chatter of bus drivers, commercial radio stations, wireless internet modems, airplane tracking signals, satellite broadcasts and much much more. The radio wave has interesting properties, signals can propagate across the earth, reach us from outerspace and transcend political borders. These signals, while physical and legistlated, are difficult to 'own' and in a way the 'hertzian space' can be interpreted as a commons, like the air we breathe and the water we drink. 

Radio now is  an 'old medium', it is unaffected by the  promises and expectations that  charactarize 'new media'. Utopias have  been replaced by (capitalist)  realisms and to a large extent radio has  left our space of imagination.  Alternative and subversive radio  practices have diminished, pirate radio  for example gave way to  internet streaming stations in many countries.  At the same time it is  radio technology that lies at the base of newer  developments and  concepts like the internet of things, smart cities,  distributed sensor  networks and their implied modes of governance. So  while they might no  longer lie at the focus of our attention, wireless  technologies still  have strings attached to them. 

What is made invisible or what is conciously not mapped can be read as a way to enforce control. Think of sea maps that don't include depth measurements, yet are available for a few. Common maps (or interfaces for that matter) represent powerstructures by emphazising some mechanisms and leaving out others. Making new maps can be a way to reveal them and open a space for critique or intervention. 


Possible approaches and connections

Radio spectrum walk
A city walk as one of the practical approaches into the subject. Scanning the spectrum while paying attention at the interplay between wireless technologies and architecture (antenna farms, towers etc), walking around and discovering what's on either side of the 'known' FM-spectrum, identifying that and coupling it to specific technologies or practices. The mapping could happen on site in the street as some sort of 'war chalking' exercise. Perhaps in collaboration with the data/network/film city track 2 

Building of micro transmitters
Based on the ideas of MicroFM by Tetsuo Kogawa (*). Building miniature transmitters to understand the physical basics of the transmission devices but also of transmission protocols. Using these transmitters to transmit data and get a feeling for the 'weight' of data.  Parts for the microFM transmitter could be bought beforehand but a more interesting approach would be to scavenged from e-waste during the city walk. Looking for the terniary logic in creating such devices from scraps and adhoc components could fit in what that track as well. After going from self-built transmitters we could look into other approaches such as PiFM to ex. 
(*) http://www.translocal.jp/radio/m cro/howtotx.html



Software defined radio (SDR)
The main idea behind SDR is that to replace components in radios that are traditionally hardware (such as filters, mixers and amplifiers) by software algorithms. An SDR thus receives 'everything' it can receive and sends that to the computer to be processed.
 SDR recently became popular and affordable through RTL-SDR. RTL-SDR uses DVB dongles based on RTL chips (http://www.rtl-sdr.com/ ) Depending on the chipsets SDR can receive roughly between 22mhz and 2200mhz.

Other SDR hardware: 
    HackRF( http://greatscottgadgets.com/hackrf/ ), 1 MHz to 6 GHz, receive and transmit(!), open hardware
    HackRF Blue ( http://hackrfblue.com/ ), Clone of HackRF
    BladeRF ( http://www.nuand.com/ ), 300mhz - 3.8 Ghz
    rad1o ( https://rad1o.badge.events.ccc.de/ ), 50 MHz - 4000 MHz
    
Buying hardware

Software for SDR

There are various programs to interface with SDR both GUI and non-gui:

GQRX
http://gqrx.dk/
a GUI receiver works great with on your favorite distro or OSX
apt-get install gqrx-sdr

GnuRadio + GnuRadio Companion
http://gnuradio.org
Set of libraries  for doing SDR. GQRX is built on top of it. 
C++ with a lot of python bindingings

GnuRadio Companion is a visual programming (think: pure data) tool to control the SDR on a pretty low level.
The software allows to use 'blocks' of standard signal processing functions and connect them together. The blocks are then 'compiled' to a python script.
These blocks can also be modified or expanded easily withing the GRC by just writing more python to them. It's a very easy way to create GUI SDR programs.
Some examples: https://github.com/argilo/sdr-examples



http://kmkeen.com/rtl-demod-guide/index.html

Decoding

Increasingly 

MINIMODEM
http://www.whence.com/minimodem/

MULTIMON NG
https://github.com/EliasOenal/multimon-ng

FLDIGI
http://www.w1hkj.com/FldigiHelp-3.22/index.html

SIGMIRA
http://www.saharlow.com/technology/sigmira/

Calibratring your SDR
https://github.com/steve-m/kalibrate-rtl

Radio is data

but also possible with HackRF 

If you 





Links:
            http://civicpaths.uscannenberg.org/the-dark-side-of-diy-makerspaces-and-the-long-weird-history-of-diy-hobbyists-military-funding/  


Miscellanea :
    1-16 of 86,622,181 results for "wireless"  - Amazon.com
    
    Military view on 'the commons'
"The  Origins of Command United States command of the commons—maritime and  otherwise —is predicated upon core military capabilities. The first is  an open-ocean anti-submarine capability, maintenance of which is “key to  maintaining command of the sea.” Second is the military use of space  for reconnaissance, navigation, and communication purposes. Third is the  ability to launch precision-guided weaponry against an adversary?s  military forces from airplanes flying above 15,000 feet. The fourth  encompasses the ability to organize and command military forces  operating around the world via the Unified Command Plan. Underwriting  all  of this is a global network of bases and p"

http://newamerica.net/sites/newamerica.net/files/policydocs/Lalwani.%20Shifrinson.%20Whither%20Command%20of%20the%20Commons.%20Choosing%20Security%20Over%20Control%202.0.pdf



----- the same, just in MD:

#Wirelessness
( proposed by Roel Roscam Abbing + Dennis de Bel + Alejo Duque )

When speaking about invisible technologies radio is perhaps both the most invisible and yet the most present. At any given moment the air is filled signals ranging from cell phone packets, the chatter of bus drivers, commercial radio stations, wireless internet modems, airplane tracking signals, satellite broadcasts and much much more. The radio wave has interesting properties, signals can propagate across the earth, reach us from outerspace and transcend political borders. These signals, while physical and legistlated, are difficult to 'own' and in a way the 'hertzian space' can be interpreted as a commons, like the air we breathe and the water we drink. 

Radio now is  an 'old medium', it is unaffected by the  promises and expectations that  charactarize 'new media'. Utopias have  been replaced by (capitalist)  realisms and to a large extent radio has  left our space of imagination.  Alternative and subversive radio  practices have diminished, pirate radio  for example gave way to  internet streaming stations in many countries.  At the same time it is  radio technology that lies at the base of newer  developments and  concepts like the internet of things, smart cities,  distributed sensor  networks and their implied modes of governance. So  while they might no  longer lie at the focus of our attention, wireless  technologies still  have strings attached to them. 

What is made invisible or what is conciously not mapped can be read as a way to enforce control. Think of sea maps that don't include depth measurements, yet are available for a few. Common maps (or interfaces for that matter) represent powerstructures by emphazising some mechanisms and leaving out others. Making new maps can be a way to reveal them and open a space for critique or intervention. 

## Possible approaches and connections
#### Radio spectrum walk
A city walk as one of the practical approaches into the subject. Scanning the spectrum while paying attention at the interplay between wireless technologies and architecture (antenna farms, towers etc), walking around and discovering what's on either side of the 'known' FM-spectrum, identifying that and coupling it to specific technologies or practices. The mapping could happen on site in the street as some sort of 'war chalking' exercise. Perhaps in collaboration with the data/network/film city track 2 

#### Building of micro transmitters

Based on the ideas of MicroFM by [Tetsuo Kogawa]( http://www.translocal.jp/radio/m cro/howtotx.html). Building miniature transmitters to understand the physical basics of the transmission devices but also of transmission protocols. Using these transmitters to transmit data and get a feeling for the 'weight' of data.  Parts for the microFM transmitter could be bought beforehand but a more interesting approach would be to scavenged from e-waste during the city walk. Looking for the terniary logic in creating such devices from scraps and adhoc components could fit in what that track as well. After going from self-built transmitters we could look into other approaches such as PiFM to ex.



## Radio tools

### Software defined radio (SDR)
The main idea behind SDR is that to replace components in radios that are traditionally hardware (such as filters, mixers and amplifiers) by software algorithms. An SDR thus receives 'everything' it can receive and sends that to the computer to be processed.

SDR recently became popular and affordable through RTL-SDR. RTL-SDR uses DVB dongles based on [RTL chips]( http://www.rtl-sdr.com/ ) Depending on the chipsets SDR can receive roughly between 22mhz and 2200mhz.

**Other SDR hardware**
- [HackRF]( http://greatscottgadgets.com/hackrf/ ), 1 MHz to 6 GHz, receive and transmit(!), open hardware
- [HackRF Blue]( http://hackrfblue.com/ ), Clone of HackRF
- [BladeRF]( http://www.nuand.com/ ), 300mhz - 3.8 Ghz
- [rad1o]( https://rad1o.badge.events.ccc.de/ ), 50 MHz - 4000 MHz
    
**Buying hardware**
if you wish to buy one of the RTL-SDR dongles make sure the DVB device has one of the chipsets listed [here]( http://sdr.osmocom.org/trac/wiki/rtl-sdr)

### Software for SDR
There are various programs to interface with SDR both GUI and non-gui:
##### [GQRX]( http://gqrx.dk/)
a GUI receiver that is easily installed on your favorite distro or OSX. Uses The Waterfall as a way to visually represent activity on the radio spectrum. (apt-get install gqrx-sdr)

##### [GnuRadio + GnuRadio Companion]( http://gnuradio.org)

GnuRadio is a set of libraries for doing SDR. GQRX is built on top of it. Mostly C++ but with a with a lot of python bindingings

**GnuRadio Companion** is a visual programming tool (think: pure data / maxmsp interface) to control the SDR on a pretty low level. The software allows to use 'blocks' of standard signal processing functions and connect them together. The blocks are then 'compiled' to a python script.
These blocks can also be modified or expanded easily withing the GRC by just writing more py thon to them. It's a very easy way to create specific/custom GUI SDR programs.
Some examples: https://github.com/argilo/sdr-examples



#### The Waterfall

[]( http://farm6.staticflickr.com/5520/9300199921_4c0ce4e4a4_z.jpg)
The typical interface for SDR is the so-called waterfall, which is a visual representation of a slice of the spectrum. It represents the signal to noise ratio on the spectrum, plotted in in time. Usually representing blue as the noise floor and any peaks in signals als yellow/ red that scroll down. That allows to one to visually discover signals, even after they have stopped transmitting, rathter than having to be tuned in at the right time to hear them.

There are however some downsides to the Waterfall, the slice of spectrum that you can plot is limited to the native bandwith of the SDR receiver (in the case of RTL-SDR this is usually around 8mhz). Also the amount of time that gets visualized is rather limited, around 20 seconds so its also easy to 'miss' transmissions if you didn't see them in time. 

#### The Commandline

There are some command line tools for SDR. Most of these only produce I/Q datasets which can then be piped into either sound players or plotting software.

Some examples include:
- rtl_power,