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Freifunk mit Ubiquiti UniFi AP

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Freifunk.net

Inhalt

Was ist Freifunk.net?

Die Initiative Freifunk.net ist ein nicht-komerzielles, gemeinschaftliches Projekt vieler Freiwilliger, die sich zum Ziel gesetzt haben ein unabhängiges und dezentrales WLAN-Netzwerk aufzubauen, welches von Jederman frei zugänglich, unzensiert und anonym verwendet werden kann und außerdem die Netzneutralität wahrt. Die Initiative ist dabei in lokalen Freifunk-Communities organisiert, welche in jeder größeren und kleineren Stadt anzutreffen sind.

Das Freifunk-Netz erstreckt sich bereits über ganz Deutschland und wächst mit jedem Unterstützer ein Stückchen weiter. Ob auch in deiner Nähe schon ein Freifunk-Zugangspunkt ist, über den du ohne Anmeldung einen freien Internet-Zugang bekommen kannst, erfährst du auf der Freifunk-Karte!

Mitmachen darf jeder! Zum Unterstützen der Idee tritt man am besten mit seiner lokalen Freifunk-Community in Kontakt. Dort kann man sich informieren und austauschen und im Regelfall auch einen eigenen, vorkonfigurierten Freifunk-Router ab 20€ beziehen. Schau also einfach vorbei, z.B. bei Freifunk-München!

Freifunk verbindet!

Freifunk Technik

Freifunk ist als Mesh-Netzwerk konzipiert. Das bedeutet, dass sich benachbarte Freifunk-Router (Knoten) automatisch miteinander verbinden. Netzwerk-Pakete werden dann auf ihrem Weg vom Benutzer (z.B. Smartphone) von Knoten zu Knoten weitergeleitet bis sie ihr Ziel (z.B. Wikipedia) erreichen. Um auch in Situationen in denen keine benachbarten Freifunk-Knoten in Reichweite sind einen Zugang zum Freifunk-Netz zu bekommen, betreiben die Freifunk Communities VPN-Gateways. Isolierte Knoten können so über den privaten Internetzugang des Knoten-Betreibers eine verschlüsselte VPN-Verbindung zum restlichen Freifunk-Netz herstellen. Vom VPN-Gateway aus kann – über eine Verbindung ins Ausland – auch das Internet erreicht werden. Auf diese Weise wird geschickt das rechtliche Problem der deutschen Störerhaftung umgangen.

Auf Freifunk-Routern läuft eine speziell angepasste Version der freien OpenWrt Firmware, namens Gluon. Gluon stellt dabei eine stark vereinfachte Web-Oberfläche bereit, welche zum Einrichten und Konfigurieren eines Freifunk-Knotens verwendet werden kann. Außerdem enthält Gluon einen Autoupdater, welcher den eigenen Freifunk-Knoten immer automatisch auf den aktuellen Softwarestand updatet. Für erfahrene Benutzer gibt es zusätzlich die Möglichkeit sich per SSH auf dem Router einzuloggen, um den vollen Funktionsumfang von OpenWrt auszunutzen.

Unterstützte Hardware

Durch die OpenWrt Basis der Freifunk Firmware “Gluon” gibt es eine breite Auswahl an unterstützen Routern. Zu den geläufigsten Modellen zählen Router der Firmen TP-Link und Ubiquiti Networks. Welche Router im einzelnen unterstützt werden erfährt man auf der Website der lokalen Freifunk-Community. Wegen eines sehr guten Preis-Leistungs-Verhältnisses (Preis < 20€) erfreut sich der Router “TP-Link TL-WR841N” zur Zeit sehr großer Beliebtheit.

Ubnt UniFi APIch habe mich für meinen ersten Freifunk-Knoten für das Modell “Ubiquiti UniFi AP Long Range” (Ubnt UAP-LR) entschieden. Dieser bietet eine sehr gute Reichweite von bis zu 180m, eine leichte Verkabelung dank Stromversorgung über das Netzwerkkabel und wird offiziell von meiner Freifunk-Community (Freifunk-München) unterstützt. Die Freifunk Installation und Konfiguration dieses Routers möchte ich im folgenden exemplarisch für “Freifunk-München” erläutern.

UniFi Router flashen

Nach dem Auspacken und Anschließen des UniFi AP ans lokale Heim-Netzwerk bekommt dieser per DHCP automatisch eine IP-Adresse zugewiesen (<UAP-IP>), welche in der Web-Oberfläche des privaten Internet-Routers (z.B. FritzBox) nachgeschaut werden kann. Mit einem Linux-Computer erfolgt die Installation der Freifunk Firmware (Gluon) auf dem UniFi AP danach in 3 einfachen Schritten:

  1. Via SSH in die original Software des UAP einloggen: 
    ssh ubnt@<UAP-IP> #(Passwort: ubnt)
  2. UniFi Factory-Firmware der lokalen Freifunk-Community ins /tmp Verzeichnis des Routers downloaden, z.B.: 
    cd /tmp
wget http://firmware.ffmuc.net/stable/factory/gluon-ffmuc-v2015.2-ubiquiti-unifi.bin
  3. Freifunk-Firmware auf den Router flashen: 
    fwupdate.real -m gluon-ffmuc-v2015.2-ubiquiti-unifi.bin -d

Nachdem das Kommando ‘fwupdate.real’ erfolgreich ausgeführt wurde, gibt es das Wort “Done” aus und der Router kann vom Strom-/Netzwerkkabel und vom Heim-Netzwerk (am PoE-Adapter) getrennt werden. (Quelle)

UniFi Router konfigurieren

Anstelle vom Heim-Netzwerk (z.B. FritzBox) sollte der Router jetzt direkt mit dem eigenen Computer verbunden werden. Nachdem das Strom-/Netzwerkkabel wieder angesteckt wurde startet der UniFi AP die neu installierte Freifunk-Firmware im Setup/Config-Mode. Alternativ erreicht man den Config-Mode durch drücken der Reset-Taste für ca. 3 Sekunden. Den Config-Mode kann man daran erkennen, dass die grüne LED des Routers blinkt (ca. 1x pro Sekunde).

Gluon Web UIIm Config-Mode hat der UAP die IP-Adresse 192.168.1.1 und betreibt einen DHCP-Server, so dass der eigene Computer automatisch eine IP-Adresse aus dem Bereich 192.168.1.x/24 zugewiesen bekommen sollte. Alternativ kann dem eigenen Computer auch manuell eine IP-Adresse aus diesem Bereich gegeben werden (z.B. 192.168.1.100). Steht die Verbindung zwischen Computer und Router, kann die Gluon Web-Oberfläche auf http://192.168.1.1 erreicht werden.

Die Gluon Web-Oberfläche stellt verschiedene Felder zum Konfigurieren des Knoten bereit (Name, Kontakt, Geo-Koordinaten, Bandbreitenlimitierung, …) und ist weitgehend selbsterklärend. Nach abschließen der Konfiguration muss der Router nochmals neu gestartet werden. Auch kann er nun wieder mit dem lokalen Heim-Netzwerk verbunden werden, so dass er ggf. übers Internet eine Verbindung zum Freifunk-VPN-Gateway herstellen kann. Der Router startet nun in den Normal-Mode: Die grüne LED leuchtet dauerhaft.

Für erfahrene Benutzer gibt es zusätzlich zum Normal-Mode und Config-Mode auch noch den Failsafe-Mode. Dieser kann erreicht werden wenn im Bootvorgang des Routers mehrfach die Reset-Taste gedrückt wird. Im Failsafe-Mode blinkt die grüne LED sehr schnell (schneller als 1x pro Sekunde). In diesem Modus sind alle Services deaktiviert und der Router ist nur per Telnet/SSH auf 192.168.1.1 zu erreichen.
(Quelle 1, Quelle 2, Quelle 3)

Viel Spaß mit eurem eigenen Freifunk-Knoten!

What’s New in the Linux Network Stack?

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Recently, I attented a seminar at university and created a paper named “What’s New in the Linux Network Stack?”. As the content of my paper might be of interest to some people in the community, I decided to publish it here.

Abstract
In this paper, interesting features of the Linux kernel’s network stack are analyzed, which were introduced during the development cycles from Linux v3.7 to Linux v3.16. Special attention is given to the low-latency device polling, introduced in Linux v3.11, the netfilter’s SYNPROXY target, introduced in Linux v3.12 and the new Nftables framework, introduced in Linux v3.13. At the end a trend is presented, which shows the direction in which the Linux network stack is evolving.

What's New in the Linux Network Stack

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Feel free to study, improve and build upon my work as desired! Feedback is welcome.

Update: This paper is now formally released in the “Proceedings of the Seminars Future Internet (FI) and Innovative Internet Technologies and Mobile Communications (IITM)”, which can be found here: DOI: 10.2313/NET-2015-03-1

Introducing OpenPhoenux Neo900

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openphoenux-logoThe latest device in the OpenPhoenux open hardware familiy is the Neo900, the first true successor to the Nokia N900. The Neo900 is a joint project of the Openmoko veteran Jörg Reisenweber and the creators of the GTA04/Letux2804 open hardware smartphone at Golden Delicious Computers. Furthermore, it is supported by the N900 Maemo5/Fremantle community, the Openmoko community and the OpenPhoenux community, who are working together to get closer to their common goal of providing an open hardware smartphone, which is able to run 100% free and open source software, while being independent of any big hardware manufacturer.

OpenPhoenux Neo900
OpenPhoenux Neo900

With the big ecosystem of free and open Maemo5/Fermantle applications, the hacker friendly N900, which provides an excelent hardware keyboard, the variety of free operating systems of the Openmoko community (SHR, QtMoko, Replicant, …) and the experience in designing and producing open hardware devices of the OpenPhoenux community (e.g. GTA04), they want to bring the best of all worlds together in one single device, the Neo900.

The Neo900 is meant to be an upgraded N900, with a newly designed and more powerfull motherboard, which is based upon the existing and tested OpenPhoenux GTA04 design. Together with the nice housing of the N900 (e.g. slider, hardware keyboard, big screen, …), this is trying to get “the hackers most beloved device”. In the same spirit of the OpenPhoenux community, which created unique cases for their GTA04 devices out of aluminium, wood or 3D printing, there is also an effort to build an aluminium housing for the N900, which might lead to personalized and self-produced cases for the Neo900 in the future and thus the independence of spare parts of N900 smartphones.

n900-cover1 n900-cover2

Due to the fact that the Neo900’s new motherboard is very similar to the GTA04, it is possible to reuse most of the low level software stack like development tools, the Bootloader and the Linux Kernel from the GTA04 project, with just minor modifications applied. This will speed up the software development process of this new open hardware platform a lot!

To fund the development and prototyping of this new open hardware device, which is made in Germany, a crowdfunding campain has been started a few days ago, in order to collect 25.000€ (which is by now already halfway reached!). Depending on the outcome of this fundraising the project might be able to provide better hardware specs than the following minimum keyfeature set:

  • TI DM3730 CPU (OMAP3 ARM Cortex A8) with 1+ GHz
  • 1GB RAM, 512MB NAND flash, 32+ GB eMMC, Micro-SD-Reader
  • 3.75G module for UMTS/CDMA; 4G (LTE) optional
  • USB 2.0 OTG High Speed
  • GPS+GLONASS, WLAN, Bluetooth
  • Accelerometer, barometric Altimeter, Magnetometer, Gyroscope
  • VGA (front) + 5MP (rear) camera

DSC01773 DSC01774

If you want to see the N900 to live on, help the independet open hardware community to succeed, or are looking for a new, hacker friendly smartphone, you should consider to support the fundraising with a donation. If you donate 100€ or more, your donation will also serve as a rebate for a finished device, once they are ready.

[Update 2013-11-04] The goal of 25.000€ is now reached, less than a week after the fundraiser started! Thanks to everybody who donated and spread the word and thus helped to make that happen. If you want to qualify for the rebate on the finished device, it is still possible to donate.

Let the OpenPhoenux fly on!

Youtube

Determining Interaction Geometry with Ultrasound Sensors

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Just recently I finalized my Bachelor’s Thesis in Computer Science at the Technical University of Munich. The thesis is licensed under the Creative Commons CC-BY-SA 3.0 Unported license and is now available for download.

Abstract
In this thesis I present an ultrasound tracking system, which works infrastructure less and is based on mobile phones. I present the software and hardware, which is needed for this system to work. Then I describe the experiment I conducted to collect data of the system’s performance. Afterwards, this data gets evaluated in a way that it is compared to a high precision reference data set, which was already used to determine interaction geometry. Next, I discuss the system’s and experiment’s limitations and suggest some concrete improvements. Finally I conclude on the possibilities to determine interaction geometry, using the data my ultrasonic tracking system is able to collect and propose some future work in this area.

determining-interaction-geometry-with-ultrasound-sensors

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The corresponding software is licensed under the MIT license and is available for download as well: software.tar.bz2

Feel free to study, improve and build upon my work as desired! Feedback is welcome.

Categories Me

OpenPhoenux LinuxTag 2013 Impressions

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LinuxTag-Logo
The LinuxTag 2013 is over, and I want to share some brief impressions I got during our stay in Berlin.

The LinuxTag is a nice and well organized FOSS exhibition in Germany, attracting more than 10.000 visitors during 4 days.

We gave a talk about the OpenPhoenux project at the 2nd evening and had about 60 listeners. Some of them got very interested and followed us to the booth afterwards. For everyone who couldn’t participate, the slides are available online: Slides.pdf

We shared a booth with some other “Linux & Embedded” projects, namely: OpenEmbedded, Ethernut, Nut/OS, Oswald/Metawatch. Our Booth was professionally looking and I think we got quite some people interested in the project. Basically we had a constant flow of people at the booth during our 3 days stay and the overall feedback was rather positive!

OpenPhoenux LinuxTag 2013 (1) OpenPhoenux LinuxTag 2013 (2) OpenPhoenux LinuxTag 2013 (3)

We got interviewed by the “GNU funzt!” team, as well. The (german) video is now available on Youtube (OpenPhoenux interview is starting at 5:00):


All in all it was a very nice stay in Berlin. I especially enjoyed meeting and chatting with guys who already owned a GTA04. It looks like the community is growing again!

Links:

OpenPhoenux FOSDEM Impressions

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CIMG0210FOSDEM 2013 is over and I had a really nice time again at Brussels, together with the OpenPhoenux/GTA04 team. It was especially nice to meet some people from our community in person and discuss interesting ideas with them.

Furthermore, it was great to meet people, who didn’t know about neither OpenPhoenux nor Openmoko, having cool ideas, which the OpenPhoenux GTA04 open hardware plattform would enable them to do.

We even got interviewed by Sam – a moviemaker, ceating a movie called “Year of Open Source” about living in a free software/hardware world for (at least) one year.

As stated, I had a nice time and I’m looking forward to meeting with the OpenPhoenux community soon again. Now, as a picture says more than 1000 words, here are some photographs from our FOSDEM booth:

Update: Now there is a video available as well.

OpenPhoenux at FOSDEM 2013

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openphoenux-logo
The team of OpenPhoenux presented the development process of the open hardware and free software powered mobile plattform “GTA04” at FOSDEM 2011 and 2012, including working prototypes and preview-boards for developers.

OpenPhoenux-3704Now, that the OpenPhoenux has taken off to reach a broader audience, we’ll show off all the open hardware (prototypes of new products and finished devices) at FOSDEM 2013. We hope you’re already eager to have your hands on the latest and greatest open mobile handhelds, which will be presented at our booth!

All of those are based on the GTA04 open mobile plattform, whose latest revision GTA04-A5 is ready and waiting for pre-orders to finance the next production run.

In addition, there are still a few complete GTA04 (revision A4) smartphone units on stock at the Openmoko reseller Pulster.eu. Contact him for further information.

Those are all great hardware projects for Linux/FOSS enthusiasts and freedom lovers! But the World of OpenPhoenux is not limited to hardware gadgets, but is connected to several other open mobile and communication projects, as well:

SHR    

So, if you’re visiting FOSDEM this year and are interested in open mobile communications it is a must to drop by the “World of OpenPhoenux”-booth (No. 3) in building AW, right next to Jolla/Sailfish, Hackable Devices/MakerBot, Enlightenment and more!

We’re looking forward to meet you there, answer your questions and demo the devices to you!

AW_stands

Reconsider ancient wisdom…

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“If you have an apple and I have an apple and we exchange these apples then you and I will still each have one apple. But if you have an idea and I have an idea and we exchange these ideas, then each of us will have two ideas.”

— George Bernard Shaw

Openmoko/OpenPhoenux GTA04 jumps off

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Table of Contents

gta04+pcblayout

The Story

All started off after Openmoko Inc. began to ship the Openmoko Neo 1973 (GTA01) and Neo Freerunner (GTA02) in 2007, which are fully open source smartphones. A dream became true for many open source lovers and technology enthusiasts at that time.

Sadly, Openmoko Inc. canceled their efforts for an open smartphone in 2009. But due to their openness (schematics, hardware specifications, software) it was possible for enthusiasts from the Openmoko community, with great support from Golden Delicious Computers (one of the german Openmoko distributors), to develop a new and modern open smartphone – the OpenPhoenux GTA04.

Technical Specifications

DSC00972

  • 1GHz ARM Cortex-A8 processor (DM3730)
  • PowerVR integrated graphics (SGX530)
  • 2.8” resistive VGA touchscreen
  • HSDPA 3G modem (Option GTM601)
  • 512MB RAM
  • 1GB internal memory & SDHC card slot (up to 32GB)
  • WLAN, Bluetooth, GPS, FM Transceiver
  • Accelerometer, Compass, Gyroscope, Barometric Altimeter
  • USB 2.0 OTG port, 2.5mm headset port, GPS antenna port, video out

Prototypes & First production run (2012)

om_beagle_hybrid
Golden Delicious Computers and the enthusiasts from the Openmoko community started off with the idea of stuffing a BeagleBoard into a Neo Freerunner case and connecting an USB UMTS dongle to it – this was the first prototype GTA04A1, announced in late 2010 and presented at OHSW 2010 and FOSDEM 2011.

Next, they started to integrate all of this onto a single PCB of the same size as the Neo 1973/Freerunner boards, so it could fit into their cases, use their batterys, antennas, speakers, buttons and touchscreens. This board was then called GTA04A2 – the second prototype, which had quite some problems. A redesign of that prototype resulted to the GTA04A3 “Early-Adpoter” boards, which were shipped to about 20 develpoers, enabling them to start with software development for the platform.
LinuxTag12The next step was to reach out to the people by presenting the project on other conventions like the FOSDEM 2012, Openmobility 2012, Linuxwochen 2012 and the LinuxTag 2012, to produce bigger batches of GTA04s. To finance the first production run of the GTA04A4 (which includes some more fixes over the GTA04A3) Goldelico collected pre-orders from interested people from the Openmoko community. They were able to collect about 250 pre-orders and were thus able to start the first big OpenPhoenux production run.

GTA04 Boards in vapour phase soldering machine
GTA04 Boards in vapour phase soldering machine
Unfortunately, “mass”-production turned out not to be an easy task. Goldelico had to find, analyse and solve a lot of problems within the production line and especially in the soldering process, which took a lot of time. Because of all the troubles the people who pre-ordered in the beginning had to wait about 1 year to finally get their devices. At the end of 2012 all problems were solved and the “Group-Tour” had successfully finished. The GTA04 team is very happy to have reached that big milestone. Now that there are about 300 GTA04s (A3+A4) out in the wild, the interest in the Linux/FOSS community seems to be growing for our project. To satisfy that growing demand Goldelico will happily produce more GTA04s of revision A5 (which will include some minor fixes over the A4).

“Now as we have finally learned everything about mass production […], it is time to kick-start the next [production run].” (Dr. Schaller, Golden Delicious Computers)

Next production run (2013) – Out now!

DSC01512To finance the 2nd production run of about 200 more GTA04 boards Goldelico started to collect pre-orders just recently. The production should run smoothly that time, as there were no big changes and the process is known. Production will start in march 2013 and the boards should ship shortly after that.

If you’re interested in pre-ordering one of those new A5 boards, check out the Handheld-Linux store. If you’re interested in getting a complete “Letux 2804” unit (GTA04 board build into an Openmoko Freerunner case) now you can get it from the first OpenPhoenux reseller Pulster.eu (stock is limited!).

OpenPhoenux ecosystem

openphoenux
While preparing the next revision of the GTA04 and solving production problems, the guys at Goldelico started to experiment with other GTA04 powered devices. So it is no secret, that there is already an open GTA04 tablet prototype (Letux 7004) and the ready to use GTA04 professional PDA (Letux 3704), which can be used e.g. in logistics (RFID), measurement (GPS) or guiding tasks (big sunlight readable screen & long lasting battery).
The software for the GTA04 is already in a good shape as well. Besides the Debian (squeeze) hardware-validation image, there is the Debian based QtMoko distribution and the FSO based SHR distribution, which makes the GTA04 useable as a daily phone. Furthermore, a port of Replicant (fully open source Android) is in the works. All in all the GTA04 owners in the OpenPhoenux community seem to be satisfied with their devices, so is Nikolaus Schaller from Goldelico:

“[…] I enjoy every day to be member of this OpenPhoenux community. Let’s make the OpenPhoenux fly to new levels next year!” (Dr. Schaller, Golden Delicious Computers)

I really appreciate to see our community grow again and can just second Nikolaus’ sentence. I wish the community a successful year 2013, in which we can satisfy a lot of free software enthusiasts and freedom lovers needs. OpenPhoenux – Free your phone!

Some more Goodies

There are still some more goodies in the pipeline… So stay tuned!


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