blog/data/2013-10-11-mesh-network-oslo.txt

   1 Title: Oslo community mesh network - with NUUG and Hackeriet at Hausmania
   2 Tags: english, nuug, freedombox, mesh network
   3 Date: 2013-10-11 14:10
   4
   5 <p>Wireless mesh networks are self organising and self healing
   6 networks that can be used to connect computers across small and large
   7 areas, depending on the radio technology used.  Normal wifi equipment
   8 can be used to create home made radio networks, and there are several
   9 successful examples like
  10 <a href="http://www.freifunk.net/">Freifunk</a> and
  11 <a href="http://www.awmn.net/">Athens Wireless Metropolitan Network</a>
  12 (see
  13 <a href="http://en.wikipedia.org/wiki/List_of_wireless_community_networks_by_region#Greece">wikipedia
  14 for a large list</a>) around the globe.  To give you an idea how it
  15 work, check out the nice overview of the Kiel Freifunk community which
  16 can be seen from their
  17 <a href="http://freifunk.in-kiel.de/ffmap/nodes.html">dynamically
  18 updated node graph and map</a>, where one can see how the mesh nodes
  19 automatically handle routing and recover from nodes disappearing.
  20 There is also a small community mesh network group in Oslo, Norway,
  21 and that is the main topic of this blog post.</p>
  22
  23 <p>I've wanted to check out mesh networks for a while now, and hoped
  24 to do it as part of my involvement with the <a
  25 href="http://www.nuug.no/">NUUG member organisation</a> community, and
  26 my recent involvement in
  27 <a href="https://wiki.debian.org/FreedomBox">the Freedombox project</a>
  28 finally lead me to give mesh networks some priority, as I suspect a
  29 Freedombox should use mesh networks to connect neighbours and family
  30 when possible, given that most communication between people are
  31 between those nearby (as shown for example by research on Facebook
  32 communication patterns).  It also allow people to communicate without
  33 any central hub to tap into for those that want to listen in on the
  34 private communication of citizens, which have become more and more
  35 important over the years.</p>
  36
  37 <p>So far I have only been able to find one group of people in Oslo
  38 working on community mesh networks, over at the hack space
  39 <a href="http://hackeriet.no/">Hackeriet</a> at Husmania.  They seem to
  40 have started with some Freifunk based effort using OLSR, called
  41 <a href="http://oslo.freifunk.net/index.php?title=Main_Page">the Oslo
  42 Freifunk project</a>, but that effort is now dead and the people
  43 behind it have moved on to a batman-adv based system called
  44 <a href="http://meshfx.org/trac">meshfx</a>.  Unfortunately the wiki
  45 site for the Oslo Freifunk project is no longer possible to update to
  46 reflect this fact, so the old project page can't be updated to point to
  47 the new project.  A while back, the people at Hackeriet invited people
  48 from the Freifunk community to Oslo to talk about mesh networks.  I
  49 came across this video where Hans Jørgen Lysglimt interview the
  50 speakers about this talk (from
  51 <a href="https://www.youtube.com/watch?v=N2Kd7CLkhSY">youtube</a>):</p>
  52
  53 <p><iframe width="420" height="315" src="https://www.youtube.com/embed/N2Kd7CLkhSY" frameborder="0" allowfullscreen></iframe></p>
  54
  55 <p>I mentioned OLSR and batman-adv, which are mesh routing protocols.
  56 There are heaps of different protocols, and I am still struggling to
  57 figure out which one would be "best" for some definitions of best, but
  58 given that the community mesh group in Oslo is so small, I believe it
  59 is best to hook up with the existing one instead of trying to create a
  60 completely different setup, and thus I have decided to focus on
  61 batman-adv for now.  It sure help me to  know that the very cool
  62 <a href="http://www.servalproject.org/">Serval project in Australia</a>
  63 is using batman-adv as their meshing technology when it create a self
  64 organizing and self healing telephony system for disaster areas and
  65 less industrialized communities.  Check out this cool video presenting
  66 that project (from
  67 <a href="https://www.youtube.com/watch?v=30qNfzJCQOA">youtube</a>):</p>
  68
  69 <p><iframe width="560" height="315" src="https://www.youtube.com/embed/30qNfzJCQOA" frameborder="0" allowfullscreen></iframe></p>
  70
  71 <p>According to the wikipedia page on
  72 <a href="http://en.wikipedia.org/wiki/Wireless_mesh_network">Wireless
  73 mesh network</a> there are around 70 competing schemes for routing
  74 packets across mesh networks, and OLSR, B.A.T.M.A.N. and
  75 B.A.T.M.A.N. advanced are protocols used by several free software
  76 based community mesh networks.</p>
  77
  78 <p>The batman-adv protocol is a bit special, as it provide layer 2
  79 (as in ethernet ) routing, allowing ipv4 and ipv6 to work on the same
  80 network.  One way to think about it is that it provide a mesh based
  81 vlan you can bridge to or handle like any other vlan connected to your
  82 computer.  The required drivers are already in the Linux kernel at
  83 least since Debian Wheezy, and it is fairly easy to set up.  A
  84 <a href="http://www.open-mesh.org/projects/batman-adv/wiki/Quick-start-guide">good
  85 introduction</a> is available from the Open Mesh project.  These are
  86 the key settings needed to join the Oslo meshfx network:</p>
  87
  88 <p><table>
  89 <tr><th>Setting</th><th>Value</th></tr>
  90 <tr><td>Protocol / kernel module</td><td>batman-adv</td></tr>
  91 <tr><td>ESSID</td><td>meshfx@hackeriet</td></tr>
  92 <td>Channel / Frequency</td><td>11 / 2462</td></tr>
  93 <td>Cell ID</td><td>02:BA:00:00:00:01</td>
  94 </table></p>
  95
  96 <p>The reason for setting ad-hoc wifi Cell ID is to work around bugs
  97 in firmware used in wifi card and wifi drivers.  (See a nice post from
  98 VillageTelco about
  99 "<a href="http://tiebing.blogspot.no/2009/12/ad-hoc-cell-splitting-re-post-original.html">Information
 100 about cell-id splitting, stuck beacons, and failed IBSS merges!</a>
 101 for details.)  When these settings are activated and you have some
 102 other mesh node nearby, your computer will be connected to the mesh
 103 network and can communicate with any mesh node that is connected to
 104 any of the nodes in your network of nodes. :)</p>
 105
 106 <p>My initial plan was to reuse my old Linksys WRT54GL as a mesh node,
 107 but that seem to be very hard, as I have not been able to locate a
 108 firmware supporting batman-adv.  If anyone know how to use that old
 109 wifi access point with batman-adv these days, please let me know.</p>
 110
 111 <p>If you find this project interesting and want to join, please join
 112 us on IRC, either channel
 113 <a href="irc://irc.freenode.net/#oslohackerspace">#oslohackerspace</a>
 114 or <a href="irc://irc.freenode.net/#nuug">#nuug</a> on
 115 irc.freenode.net.</p>
 116
 117 <p>While investigating mesh networks in Oslo, I came across an old
 118 research paper from the university of Stavanger and Telenor Research
 119 and Innovation called
 120 <a href="http://folk.uio.no/paalee/publications/netrel-egeland-iswcs-2008.pdf">The
 121 reliability of wireless backhaul mesh networks</a> and elsewhere
 122 learned that Telenor have been experimenting with mesh networks at
 123 Grünerløkka in Oslo.  So mesh networks are also interesting for
 124 commercial companies, even though Telenor discovered that it was hard
 125 to figure out a good business plan for mesh networking and as far as I
 126 know have closed down the experiment.  Perhaps Telenor or others would
 127 be interested in a cooperation?</p>
 128
 129 <p><strong>Update 2013-10-12</strong>: I was just
 130 <a href="http://lists.alioth.debian.org/pipermail/freedombox-discuss/2013-October/005900.html">told
 131 by the Serval project developers</a> that they no longer use
 132 batman-adv (but are compatible with it), but their own crypto based
 133 mesh system.</p>