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
   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:</p>
  51
  52 <p><iframe width="420" height="315" src="https://www.youtube.com/embed/N2Kd7CLkhSY" frameborder="0" allowfullscreen></iframe></p>
  53
  54 <p>I mentioned OLSR and batman-adv, which are mesh routing protocols.
  55 There are heaps of different protocols, and I am still struggling to
  56 figure out which one would be "best" for some definitions of best, but
  57 given that the community mesh group in Oslo is so small, I believe it
  58 is best to hook up with the existing one instead of trying to create a
  59 completely different setup, and thus this have decided to focus on
  60 batman-adv for now.  It sure help me to  know that the very cool
  61 <a href="http://www.servalproject.org/">Serval project in Australia</a>
  62 is using batman-adv as their meshing technology when it create a self
  63 organizing and self healing telephony system for disaster areas and
  64 less industrialized communities.  Check out this cool video presenting
  65 that project:
  66
  67 <p><iframe width="560" height="315" src="https://www.youtube.com/embed/30qNfzJCQOA" frameborder="0" allowfullscreen></iframe></p>
  68
  69 <p>According to the wikipedia page on
  70 <a href="http://en.wikipedia.org/wiki/Wireless_mesh_network">Wireless
  71 mesh network</a> there are around 70 competing schemes for routing
  72 packets across mesh networks, and OLSR, B.A.T.M.A.N. and
  73 B.A.T.M.A.N. advanced are protocols used by several free software
  74 based community mesh networks.</p>
  75
  76 </p>The batman-adv protocol is a bit special, as it provide layer 2
  77 (as in ethernet ) routing, allowing ipv4 and ipv6 to work on the same
  78 network.  One way to think about it is that it provide a mesh based
  79 vlan you can bridge to or handle like any other vlan connected to your
  80 computer.  The required drivers are already in the Linux kernel at
  81 least since Debian Wheezy, and it is fairly easy to set up.  A
  82 <a href="http://www.open-mesh.org/projects/batman-adv/wiki/Quick-start-guide">good
  83 introduction</a> is available from the Open Mesh project.  These are
  84 the key settings needed to join the Oslo meshfx network:</p>
  85
  86 <table>
  87 <tr><th>Setting</th><th>Value</th></tr>
  88 <tr><td>Protocol / kernel module</td><td>batman-adv</td></tr>
  89 <tr><td>ESSID</td><td>meshfx@hackeriet</td></tr>
  90 <td>Channel / Frequency</td><td>11 / 2462</td></tr>
  91 <td>Cell ID</td><td>02:BA:00:00:00:01</td>
  92 </table>
  93
  94 <p>The reason for setting ad-hoc wifi Cell ID is to work around bugs
  95 in firmware used in wifi card and wifi drivers.  (See a nice post from
  96 VillageTelco about
  97 "<a href="http://tiebing.blogspot.no/2009/12/ad-hoc-cell-splitting-re-post-original.html">Information
  98 about cell-id splitting, stuck beacons, and failed IBSS merges!</a>
  99 for details.)  When these settings are activated and you have some
 100 other mesh node nearby, your computer will be connected to the mesh
 101 network and can communicate with any mesh node that is connected to
 102 any of the nodes in your network of nodes. :)</p>
 103
 104 <p>My initial plan was to reuse my old Linksys WRT54GL as a mesh node,
 105 but that seem to be very hard, as I have not been able to locate a
 106 firmware supporting batman-adv.  If anyone know how to use that old
 107 wifi access point with batman-adv these days, please let me know.</p>
 108
 109 <p>If you find this project interesting and want to join, please join
 110 us on IRC, either channel
 111 <a href="irc://irc.freenode.net/#oslohackerspace">#oslohackerspace</a>
 112 or <a href="irc://irc.freenode.net/#nuug">#nuug</a> on
 113 irc.freenode.net.</p>
 114
 115 <p>While investigating mesh networks in Oslo, I came across an old
 116 research paper from the university of Stavanger and Telenor Research
 117 and Innovation called
 118 <a href="http://folk.uio.no/paalee/publications/netrel-egeland-iswcs-2008.pdf">The
 119 reliability of wireless backhaul mesh networks</a> and elsewhere
 120 learned that Telenor have been experimenting with mesh networks at
 121 Grünerløkka in Oslo.  So mesh networks are also interesting for
 122 commercial companies, even though Telenor discovered that it was hard
 123 to figure out a good business plan for mesh networking and as far as I
 124 know have closed down the experiment.  Perhaps Telenor or others would
 125 be interested in a cooperation?</p>