Title: Oslo community mesh network - with NUUG and Hackeriet at Hausmania
Tags: english, nuug
Date: 2013-10-11 17:10

<p>Wireless mesh networks are self organising and self healing
networks that can be used to connect computers across small and large
areas, depending on the radio technology used.  Normal wifi equipment
can be used to create home made radio networks, and there are several
successful examples like
<ahref="http://www.freifunk.net/">Freifunk</a> and
<ahref="http://www.awmn.net/">Athens Wireless Metropolitan Network</a>
(see
<ahref="http://en.wikipedia.org/wiki/List_of_wireless_community_networks_by_region#Greece">wikipedia
for a large list) around the globe.  A nice overview of the Kiel
Freifunk community can be seen from their
<ahref="http://freifunk.in-kiel.de/ffmap/nodes.html">dynamically
updated node graph and map</a>, where one can see how the mesh notes
automatically handle routing and recover from nodes disappearing.
There is also a small community mesh network group in Oslo, Norway,
and that is the main topic of this blog post.</p>

<p>I've wanted to check out mesh networks for a while now within the
<ahref="http://www.nuug.no/">NUUG member organisation</a> community,
but my recent involvement in
<ahref="https://wiki.debian.org/FreedomBox">the Freedombox project</a>
finally lead me to give it some priority, as I suspect a Freedombox
should use mesh networks to connect neighbours and family when
possible, given that most communication between people are between
those nearby (as shown for example by research on Facebook
communication patterns).  It also allow people to communicate without
a central hub to tap into to control and listen in on the private
communication of citizens, which have become more and more important
over the years.</p>

<p>So far I have only been able to find one group of people in Oslo
working on community mesh networks, over at the hack space
<ahref="http://hackeriet.no/">Hackeriet</a> at Husmania.  They seem to
have started with some Freifunk based effort using OLSR, called
<ahref="http://oslo.freifunk.net/index.php?title=Main_Page">the Oslo
Freifunk project</a>, but this effort seem to be dead and the people
behind it have moved on to a batman-adv based system called
<ahref="http://meshfx.org/trac">meshfx</a>.  Unfortunately the wiki
site for the Oslo Freifunk project is no longer possible to update, so
the project page can't be updated to point to the new project.  The
people at Hackeriet have already invited people from the Freifunk
community to Oslo to talk about mesh networks, and I came across this
video where Hans Jørgen Lysglimt interview the speakers about their
talk:</p>

<p><iframe width="420" height="315" src="https://www.youtube.com/embed/N2Kd7CLkhSY" frameborder="0" allowfullscreen></iframe></p>

<p>I mentioned OLSR and batman-adv, which are mesh routing protocols.
There are heaps of different protocols, and I am still struggling to
figure out which one would be "best" for some definitions of best, but
given that the community mesh group in Oslo is so small, I believe it
is best to hook up with the existing one instead of trying to create a
completely different setup, and thus this have decided to focus on
batman-adv for now.  It sure help to know that the very cool
<ahref="http://www.servalproject.org/">Serval project in Australia</a>
is using batman-adv as their meshing technology when it create a self
organizing and self healing telephony system for disaster areas and
less industrialized communities.  Check out this cool video presenting
that project:

<p><iframe width="560" height="315" src="https://www.youtube.com/embed/30qNfzJCQOA" frameborder="0" allowfullscreen></iframe></p>

<p>According to the wikipedia page on
<ahref="http://en.wikipedia.org/wiki/Wireless_mesh_network">Wireless
mesh network</a> there are around 70 competing schemes for routing
packets across mesh networks, and OLSR, B.A.T.M.A.N. and
B.A.T.M.A.N. advanced are protocols used by several free software
based community mesh networks.</p>

</p>The batman-adv is a bit special, as it provide layer 2 (as in
ethernet ) routing, allowing ipv4 and ipv6 to work on the same
network.  One way to think about it is that it provide a mesh vlan you
can bridge to or handle like any other vlan on your computer.  The
required drivers are already in the Linux kernel at least since Debian
Wheezy, and it is fairly easy to set up.  A
<ahref="http://www.open-mesh.org/projects/batman-adv/wiki/Quick-start-guide">good
introduction</a> is available from the Open Mesh project.  These are
the key settings needed to join the Oslo meshfx network:</p>

<table>
<tr><th>Setting</th></th>Value</th></tr>
<tr><td>Protocol / kernel module</td><td>batman-adv</td></tr>
<tr><td>ESSID</td><td>meshfx@hackeriet</td></tr>
<td>Channel / Frequency</td><td>11 / 2462</td></tr>
<td>Cell ID</td><td>02:BA:00:00:00:01</td>
</table>

<p>The reason for setting ad-hoc wifi Cell ID is to work around bugs
in wifi card firmware and drivers.  (See a nice post from VillageTelco
about
"<ahref="http://tiebing.blogspot.no/2009/12/ad-hoc-cell-splitting-re-post-original.html">Information
about cell-id splitting, stuck beacons, and failed IBSS merges!</a>
for details.)  When these settings are activated and you have some
other mesh node nearby, your computer will be connected to the mesh
network and can communicate with any mesh node that is connected to
any of the nodes in your network of nodes. :)</p>

<p>My initial plan was to reuse my old Linksys WRT54GL as a mesh node,
but that seem to be very hard, as I have not been able to locate a
firmware supporting batman-adv.  If anyone know how to use that old
wifi access point with batman-adv these days, please let me know.</p>

<p>If you find this project interesting and want to join, please join
us on IRC, either channel
<ahref="irc://irc.freenode.net/#oslohackerspace">#oslohackerspace</a>
or <ahref="irc://irc.freenode.net/#nuug">#nuug</a> on
irc.freenode.net.</p>

<p>While investigating mesh networks in Oslo, I came across an old
research paper from the university of Stavanger and Telenor Research
and Innovation called
<ahref="http://folk.uio.no/paalee/publications/netrel-egeland-iswcs-2008.pdf">The
reliability of wireless backhaul mesh networks</a> and elsewhere
learned that Telenor have been experimenting with mesh networks at
Grünerløkka in Oslo.  So mesh networks are also interesting for
commercial companies, even though Telenor discovered that it was hard
to figure out a good business plan for mesh networking and as far as I
know have closed down the experiment.  Perhaps Telenor or others would
be interested in a cooperation?</p>