Tag: gsoc

Implementing Pop-Routing

Posted on by Gabriele Gemmi

Hi everyone!

I am Gabriele from the Ninux community. I am participating in GSoC 2016 for the first time and I am very glad I have been accepted as a Student for Freifunk. I am from Florence, Italy. Here I’m studying Computer Science, soon I will graduate and I hope to use the results of this project to write my bachelor thesis.

Four years ago, with others community networks’ enthusiasts we have funded Ninux Firenze[1], the fist Wireless Community Network in Florence where I had the chance to learn how these networks work and to meet many others people interested in this field. The network is constantly growing, and now it counts almost 20 nodes. In May ’14 I have been for the first time to Wireless Battle of the Mesh in Leipzig where I met the Freifunk community. For this GSoC I will work on a project called PopRouting[2]:

OONF (OLSRv2) is a link state routing protocol. It works sending periodical messages to his neighbors with the aim of transmitting information about topology changes. With these information each node of the network is able to calculate the paths to reach any other destination. These messages are periodically generated, based on the configuration parameter that regulates the sending interval. A short period will make the network react rapidly but it will also cause a large overhead due to control messages. Pop Routing is a recent technique that takes advantage of the knowledge of the network topology to find the optimal value for the OONF’s timers. Using Pop Routing every node computes the “betweenness centrality” of every other node and uses it to calculate the optimal trade-off between convergence and overhead for its timers. The algorithm has been developed at the UniTN and the algorithm to compute the BC in C++ is available as free software. My goal is to code a daemon (in C) that is able to calculate autonomously the BC of the network and push it to OONF using the telnet plugin.

In this month of community bonding I have been to Wireless Battle of the Mesh v9 in Oporto(PT). There I met the OONF developers and we discussed how to implement this inside OONF. I also gave a presentation on the project. After the Battlemesh I started working on the algorithm developed by UniTN and I made a C/C++ library out of it [3].

Today I will start coding for the GSoC, stay tuned and I will give you more updates soon.

 

Gabriel

 

[1]: http://firenze.ninux.org/

[2]: https://ans.disi.unitn.it/users/maccari/assets/files/bibliography/INFOCOM2016.pdf

[3]: https://github.com/gabri94/poprouting/tree/master/graph-parser

OpenWrt – poWquty (poWer quality): Computing and providing power quality information on OpenWrt routers.

Posted on by Neez El Sayed

Dear Freifunkers,

Please allow me to introduce the poWquty Project within Google Summer of Code 2016 at Freifunk.

The big picture behind this project relates to the energy production and consumption. Sustainable energy production and consumption are crucial for a prospering life on earth. The importance of energy led many theorists to even define the level of civilization by its energy profile. With the renewable energies shift the energy production paradigm from centralized to decentralized energy production which poses one of the next big challenges, which will influence the energy production in the future years.

From the big picture we move to the concrete case, increasingly faced when dealing with renewable energies: monitoring and control.
The emerging smart grids include an inherent need for communication for monitoring and control purposes in a more and more dynamic environment. One of the major challenges is monitoring the power quality parameters in a decentralized manner. In such case, decentralized information need to be retrieved and transported with the lowest latency possible. One way to solve this challenge could be to install expensive infrastructure to each point. The better way is to use wireless mesh infrastructure that could also serve this purpose.

Here where Freifunk comes in: The Freifunk mesh network is an outstanding example for a decentralized infrastructure that could be augmented with grid related functionalities to cope with future energy challenges. In order to use wireless mesh networks such as Freifunk for energy monitoring, we could use extra hardware that does the power measurements and use the wireless networks solely for transporting the information. The drawback of this is the need to install separate hardware. But, since all routers run on power, we could integrate the measurements into the router, which is the main goal of this project: to enable power quality measurements on OpenWrt.

Here is the initial plan how to do this. First we need to retrieve voltage samples from the power grid. For the beginning we will rely on an oscilloscope device that delivers the real time samples over a USB interface. This way voltage samples from the electric socket are retrieved at the router. With these voltage samples we can go ahead and calculate the power quality parameters, using moving window algorithms, fourrier transform, and z-transform to get the phase angle, the effective power, the frequency, and the harmonics. This calculation should be time, and memory efficient since it has to run on the OpenWrt embedded devices. Once these values are calculated we need to think about how we want to make them available for retrieval over IP networks.

Now we come to the Code: The goal of the project is to create an OpenWrt package which ensures three functionalities:
1-    Retrieving sample data from the measurement device
2-    Calculating power quality parameters form the retrieved samples
3-    Provisioning of the calculated parameters for retrieval

This project is intended to strengthen the role of open software in the uprising smart grids by providing some essential functionalities, communication devices need to have in the context of smart grids, especially in regard to the future role of the home routers in the future energy solutions.

More updates on this will follow in the next weeks.

Cheers,

Neez

GSoC: A new configuration system for OpenWrt/LEDE

Posted on by NeoRaider

Hi,
I’m Matthias (aka NeoRaider), and this year, I’ll participate in the Google Summer of Code for the Freifunk project.

The goal of my project is to develop an alternative to the UCI configuration system, as UCI has a number of issues that make it cumbersome to use in some situations.

One of the basic issues of UCI that affects many Freifunk (or generally community mesh) firmwares is the upgrade behaviour. Mesh firmwares usually contain elaborate default configurations, which set up network interfaces and other things to allow participating in a mesh without deep knowledge of the setup.

But this setup needs to change from time to time, as the firmware is upgraded. In the Gluon firmware framework, we usually solve this by providing upgrade scripts which modify the configuration after flashing the firmware. Writing these script is often a tedious task, and the scripts easily break when the configuration differs too much from the expected one.

But the ability to change the configuration is important for many Freifunk users: They want to change the role of ethernet ports, WLAN settings, and a lot more. But UCI doesn’t provide information how a setting was changed: if a script encounters an unexpected value, it can’t find out if it is an old default value, or was changed by the user. This often leads to a difficult choice for the script author: either to overwrite the value unconditionally, maybe disregarding voluntary configuration changes, or not to overwrite it, rendering communities unable to change certain configuration during upgrades.

My project aims at solving this by saving the user configuration independently of the defaults provided by packages. This way, a package upgrade can change the default values, but explicit user configuration will not be affected.

Another issue is that the upgrade scripts are usually part of the packages that bring the configuration. Removing a package will leave the configuration behind, which is usually a good thing (for users which know about this and may be interested in the the old config), but for mostly-automatic upgrades, old configuration may accumulate, which can quickly become problematic on devices with very limited flash.

I plan to fix this by basing the new configuration system on schema definitions, which specify which configuration options and values are valid. The schema will probably be based on JSON, as there are already lots of existing systems for defining JSON schemas, which may be used for my project or at least serve as inspiration. This will also finally provide real datatypes for the configuration and make things more consistent (finally no more 1/true/on/yes/0/false/off/no booleans!). If we want too keep the package/section/option organization of UCI, or rather allow defining schemas for any JSON structure, is still a subject of debate.

Instead of going into detail even more in this post, I’ll provide a link to my Gitlab project: https://gitlab.com/neoraider/ece

Design documents, examples for configuration and schemas, and first code will start to appear there very soon Laughing

DynaPoint – A dynamic access point validator and creator

Posted on by Tobias Ilte

Hi everybody,

 

I am Tobias, a Computer Science student at the TU-Berlin. I am glad to have the opportunity to participate at GSoC for Freifunk this year.

 

My project aims at making the handling with access points in OpenWrt/LEDE easier. The goal is defined as follows: Find an easily configurable solution (with reasonable defaults) for making the wireless access SSID in OpenWrt/LEDE dependent on a set of network conditions.

 

What does that mean? Consider the following example. You have a wireless access point with SSID “Freifunk”. Suddenly for whatever reason the AP looses Internet connectivity without anyone noticing it. When users now connect to this AP, expecting a working Internet connection, they get frustrated, because they can’t check their emails or surf the Internet.

 

With DynaPoint I want to develop a daemon, which regularly monitors the Internet connectivity. When it’s lost, the SSID will automatically be changed. In this example it could be changed to “Freifunk-offline”. When Internet connectivity is re-established, the SSID would automatically be changed back to “Freifunk”.

This way users as well as admins get informed about the state of an access point just by looking at the SSID.

 

To verify Internet connectivity the first obvious step would be to do a ping. For this purpose there already exists a package called pingcheck, which I am planning to use. Further steps could include DNS-Queries and HTTP-Downloads.

 

Speaking about easy configuration and reasonable defaults, I want to require as little configuration steps as possible, but also provide enough configuration options to be adjustable to different kind of setups. Ideally the configuration will also be possible via the LuCI web interface.

 

Until next time,

 

Tobias

SWOON: Simultaneous Wireless Organic Optimization within Nodewatcher

Posted on by David Marn

Hi everyone,

I will contribute to one of the Freifunk projects; nodewatcher, via Google Summer of Code this summer and I wanted to keep you updated on my progress as well as exchange thoughts about my ideas.

First of all, nodewatcher is an open source, modular community oriented platform used for network planning, node deployment, node monitoring and maintenance. nodewatcher was initially developed to be primarily used by the wlan slovenija project. With 1336 nodes, it’s really successful and a great example for community networks. As nodewatcher gets deployed elsewhere with even more nodes, it’s natural to ask ourselves if we can be smarter about allocating spectrum to our wireless nodes – these nodes are mostly inexpensive wireless routers but it’s natural to extend the meaning of the term to dedicated wireless access points (i.e. Unifi AP).

The theoretical foundation for this problem is fascinating by itself: Each node has a different amount of noise in each channel (the 2.4GHz band allows 3 non-overlapping channels where each channel is 20MHz wide) and each node wants to maximize its SNR (signal-to-noise ratio). I will term this as the greedy approach, which is already used in enterprise level devices. However, in an urban setting, nodes are close enough to each other for their signal to act as noise to other nodes. The greedy approach is no longer optimal as it bears a high price of anarchy. Instead, our goal is now to maximize the sum of channel capacities (under a power constraint). I will have to devise an algorithm to solve this problem and the algorithm does not seem trivial since the number of combinations is increasing exponentially with the number of nodes in the system. Even with only 10 nodes, we haveover 59000 possible allocations on 2.4GHz band and over 95 trillion on the 5GHz band.

Traditional networking literature tackles this optimization problem with Lagrange multipliers. An alternative is to look at approximate graph coloring schemes and compute chromatic numbers. I hope to experiment across various settings and approaches.
Over the course of the project, I hope to experiment with a real network which consists of at least 10 nodes and measure the improvements. One exciting thing about real life experiments is that nodewatcher was mostly used inside wlan slovenija’s network and I get to run it independently! This will probably allow me to fix some bugs on the way and contribute to nodewatcher in this aspect as well.

The algorithm will initally be developed as a nodewatcher module, but I hope to eventually port it to openwrt (possibly after the summer ends). The main difficulty is that nodewatcher can act as a central level planner, whereas the openwrt scenario requires negotiation among nodes. So it’s harder to convince a node to decrease its TX power to benefit other users. But imagine a network where nodes can communicate and achieve a socially optimal point of spectrum allocation! A glorious future awaits us.

Provide a cryptographic implementation for Qaul.net

Posted on by spacekookie

Hey there,

my name is Katharina (aka spacekookie) and I am one of the Google Summer of Code participants for Freifunk projects; qaul.net in particular.

I wanted to write up a short article on what it is I will be doing this summer, how I will do it and what I hope to achieve. This will be one of three articles published on this blog.

Qaul.net provides a mesh-wifi network for people to connect and share information to other people on the network. Like freifunk it uses the OLSR mesh routing library. But unlike freifunk it’s main goal isn’t to connect to the www-internet but rather create a network of it’s own on which people can communicate, share data and come together. No centralised infrastructure required.

Currently all traffic on qaul.net is sent in the clear which is…suboptimal. For one nothing said on the network is in any sense of the word “private”. On the other there is no way to verify identities. And that’s what my Summer of Code project is about.

The changes to the qaul.net code base required are quite extensive but with a bit of clever planning shouldn’t break too many things. The core thing required is an abstraction layer between user and network.

Currently a user gives their node a nickname and that’s then them. “Identify verification” (if you want to call it that Tongue Out) is done by checking IP addresses against nick-names. Man in the middle attacks are very easy in such a network and the only defense is the benevolence of its users.

What I thus plan to do is introduce an abstraction layer between a node, routing and what a user sees. A “user identity” which can be shared between different nodes (but doesn’t have to be), something that can be written to an addressbook and is later on verifiably the same and will make users aware if their are being man-in-the-middled, which is now much easier to verify.

In addition to that I plan to introduce asymmetric encryted messages, completely transparent to the user. While qaul.net can flood a message acress the network that should be seen by as many people as possible, there should be the ability for two people on the network to talk to each other without anybody else knowing what they’re talking about.

What’s planned is something that resembles PGP. A users identify will be their master-private key fingerprint. From that each node gets a subkey-pair (public and private). The public key will be flooded into the network for people to use to write messages to that node. The private will be unique to the node. And when sending messages to another person people can either choose “all” which means that the messages is encrypted against all (non-revoked) public keys of the target identity or choose a specific node to talk to. This implementation also allows for mailing list style group discussions.

 

Through Google Summer of Code I hope to become a regular contributer to qaul.net as I am a big fan of the project ideas. I also hope that my contributions will make it a much safer place to communicate and share information on.

As already mentioned I will be updating this blog two more times: one around the half-way point of the project and one as a wrap-up of how it all went.

If you’re interested in reading more of my insane ramblings about the project, maybe micro updates and what not, check out my personal blog https://spacekookie.de or go directly to the GSOC category.

 

Until another day,

Katharina/ spacekookie

 

Freifunk beim Google Summer of Code

Posted on by Andreas Bräu

Google nutzt für viele seiner Dienste OpenSource-Software. Mit dem Google Summer of Code möchte sich Google bei der OpenSource-Gemeinde bedanken und fördert Studenten für ein von Mai bis August laufendes Projekt mit 5500 US$ – in diesem Jahr über 1100 Studenten aus aller Welt.

Im Jahr 2014 nahm Freifunk wieder am Google Summer of Code teil. Freifunk integriert dabei als Dachorganisation weltweit Initiativen wie guifi.net, ninux.org, wlan slovenija und LibreMesh aus Argentinien. Wir bekamen in diesem Jahr 9 Slots für Projekte, die Studenten in Deutschland, Frankreich, Italien, Spanien und Slowenien bearbeiteten. Die Projekte beschäftigten sich u.a. mit der Freifunk-API, Netzwerkprotokollen und Software zum Communitymanagement. Im Freifunkblog können Details zu den Projekten nachgelesen werden.

Den Abschluss des diesjährigen Google Summer of Code bildete der Mentors Summit, zu dem jede Organisation zwei Mentoren entsenden darf. Zur Feier des 10-jährige Bestehens waren auch Teilnehmer aus den vergangegen Jahren eingeladen und der Summit wurde um einen Tag verlängert.

Freifunk fun in USA

Auf dem Programm stand auch ein Ausflug, wo wir das echte Amerika kennenlernten und gemeinsam mit Teilnehmern aus China und Vietnam Basketball trainierten.

Mehr als 600 Teilnehmer aus aller Welt trafen sich in San Jose, Kalifornien, und wir hatten die Chance uns über unsere Projekte auszutauschen, neue Kontakte zu knüpfen und nicht zuletzt den 10. Google Summer of Code zu feiern. Als Überraschungsgast zum Jubiläumsempfang war Linus Torvalds geladen. In einem Treffen hatten wir die Gelegenheit, mit ihm über Freifunk zu sprechen.

Ideen für Projekte im Jahr 2015 können schon jetzt im Wiki eingetragen werden. Falls ihr Kontakte zu Universitäten oder Fachhochschulen habt, sprecht mit Dozenten, Studenten oder Lehrstuhlinhabern, um Unterstützung für Projekte im Sommersemester 2015 zu bekommen.

Links

Projektideen http://wiki.freifunk.net/Ideas

Fotos zum Mentor Summit: https://www.flickr.com/search/?tags=gsoc14

Linus Torvalds and Dirk Hohndel meetup with Freifunk Community at Google Reunion

Posted on by Mario Behling

Freifunk attendees had the chance to discuss Community Networks with Linus Torvalds and Dirk Hohndel from Intel at the Google Mentor Summit. Linus said, it was impressive to see the growth of community networks around the world and it is exciting to see so many people working on Linux for embedded devices.

Linus Torvalds, Mario Behling, Federico Capoano, Freifunk, Google Summer of Code

GSoC: Work on Freifunk API Query Client will go on

Posted on by Martin Tippmann

This is the final blogpost for my GSoC project for the Freifunk-API Query Client.

Goals
 
We want a comfortable tool to query all the Freifunk API files as there are nearly 100 communities all over Germany providing their data. There are already several applications like our community map, a common calendar, our feed aggrator or the community podcast collector. But it’s still hard to find communities by properties like routing protocols or focus topics.
 
Challenges
 
When we began this project we only planned to query the generated JSON data for the community in a browser and additionally provide query results via a webservice. But then we talked to several people and we heard about DeepaMehta with features like connectors to OpenStreetmap. So we did something what you don’t do normally: We changed our project goals before the midterm evaluations.
 
DeepaMehta is not just another database product, it provides a different way to store and handle data. It uses a graph to store connections between items and allows to modex complex datatypes and associations between them. We had to change our mind and had to learn a new kind of thinking. The API data is constantly evolving and changing and there a lot of cross-references in the data e.g. links to various nodemaps. We think the switch to DeepaMehta is useful because we can query the graph and add new relations and data without problems.

 
It’s difficult to handle different spec versions if you want to query all API files, because some fields changed, other fields were added to the specs or got another meaning. In an ideal world all communities update their files as soon as possible. But we all know, it will never happen like that. As a workaround we first focused on less fields, available in all versions.
 
What we got
 
We’re able to import communities from the API directory as a base entity. We also tried some different ways to import and store the specs, but we need some improvements here. By using the summarized API file, the import of our payload can be done via the DeepaMehta REST API.

The switch to DeepaMehta brought a lot of complexity to the project and I’m personally not happy my results at this point because I had trouble to spend enough time for the project. Additionally some basic problems like dealing with changing schema and data import are not really solved well at this point. The data is in DeepaMehta and can be queries with the included client but it’s not in a state where it’s usable for the community.

Overall the GSoC was an interesting experience for me. Through I’ve failed to set aside enough time for the tasks. The timely overlap with university lectures does not make it easier. So I can only recommend to know beforehand that you’ll have enough time to accomplish your goals. But the support from the Freifunk community was always great and helpful! As the project is not a state that can be considered ‘ready’ I’m continuing working on it.
 
Future Plans

I definitly want to finish the work at least to point where it can be used by the wider Freifunk community.

The default DeepaMehta client isn’t designated to query a lot of fields like our API provides. Here we need a new web based client to provide users an interface to select fields and get a proper response.

Work will continue on integrating the API data and DeepaMehta.

Repository: https://github.com/freifunk/query.api.freifunk.net

Final Blog Post: Netengine

Posted on by Alessandro Bucciarelli

Hi everybody, this is going to be my last blog post as a participant of GSOC2014. I’m very sad about this, those have been very hard worked months but very formative.

I improved both my coding skills but above all I have earned a work methodology thanks to my mentor Federico, who said to me to be more reflexive and to be more precise in what I do.

I have learnt some aspect of versioning (Git) I ignored before and learned much more on Python than I did by myself.

This is the “change log” of the last time period of the program: we developed a new backend, the HTTP backend. It aims to retrieve informations from the web admin interface of AirOS devices, that’s why we called it HTTP.

We wrote documentation about all the project, describing all the things an user should do both to contribute or use Netengine, trying to be as much more clear and to make it simpler as we could.

Unfortunately this is my last year as a student, no PhD on my way (for now), so I will not be eligible at all for next editions coming.

Greetings and thanks: I would like to thank Ninux , the community network I’ve worked with. I’ve had the possibility of joining their meetings, to talk a lot with every member and to be supported every time I had some problem about what I was doing.
Obviously my mentor Federico Capoano, Mario Behling from Freifunk who supervised projects.

For further questions on the project please visit https://github.com/ninuxorg/netengine or email us at ninuxdev@ml.ninux.org or read the docs!