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1 <?xml version="1.0" encoding="utf-8"?>
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3 <channel>
4 <title>Petter Reinholdtsen - Entries tagged mesh network</title>
5 <description>Entries tagged mesh network</description>
6 <link>http://people.skolelinux.org/pere/blog/</link>
7
8
9 <item>
10 <title>Dugnadsnett for alle, a wireless community network in Oslo, take shape</title>
11 <link>http://people.skolelinux.org/pere/blog/Dugnadsnett_for_alle__a_wireless_community_network_in_Oslo__take_shape.html</link>
12 <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Dugnadsnett_for_alle__a_wireless_community_network_in_Oslo__take_shape.html</guid>
13 <pubDate>Sat, 30 Nov 2013 10:10:00 +0100</pubDate>
14 <description>&lt;p&gt;If you want the ability to electronically communicate directly with
15 your neighbors and friends using a network controlled by your peers in
16 stead of centrally controlled by a few corporations, or would like to
17 experiment with interesting network technology, the
18 &lt;a href=&quot;http://www.dugnadsnett.no/&quot;&gt;Dugnasnett for alle i Oslo&lt;/a&gt;
19 might be project for you. 39 mesh nodes are currently being planned,
20 in the freshly started initiative from NUUG and Hackeriet to create a
21 wireless community network. The work is inspired by
22 &lt;a href=&quot;http://freifunk.net/&quot;&gt;Freifunk&lt;/a&gt;,
23 &lt;a href=&quot;http://www.awmn.net/&quot;&gt;Athens Wireless Metropolitan
24 Network&lt;/a&gt;, &lt;a href=&quot;http://en.wikipedia.org/wiki/Roofnet&quot;&gt;Roofnet&lt;/a&gt;
25 and other successful mesh networks around the globe. Two days ago we
26 held a workshop to try to get people started on setting up their own
27 mesh node, and there we decided to create a new mailing list
28 &lt;a href=&quot;http://lists.nuug.no/mailman/listinfo/dugnadsnett&quot;&gt;dugnadsnett
29 (at) nuug.no&lt;/a&gt; and IRC channel
30 &lt;a href=&quot;irc://irc.freenode.net/#dugnadsnett.no&quot;&gt;#dugnadsnett.no&lt;/a&gt; to
31 coordinate the work. See also the NUUG blog post
32 &lt;a href=&quot;http://www.nuug.no/news/E_postliste_og_IRC_kanal_for_Dugnadsnett_for_alle_i_Oslo.shtml&quot;&gt;announcing
33 the mailing list and IRC channel&lt;/a&gt;.&lt;/p&gt;
34 </description>
35 </item>
36
37 <item>
38 <title>Lets make a wireless community network in Oslo!</title>
39 <link>http://people.skolelinux.org/pere/blog/Lets_make_a_wireless_community_network_in_Oslo_.html</link>
40 <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Lets_make_a_wireless_community_network_in_Oslo_.html</guid>
41 <pubDate>Wed, 13 Nov 2013 21:00:00 +0100</pubDate>
42 <description>&lt;p&gt;Today NUUG and Hackeriet announced
43 &lt;a href=&quot;http://www.nuug.no/news/Bli_med___bygge_dugnadsnett_for_alle_i_Oslo.shtml&quot;&gt;our
44 plans to join forces and create a wireless community network in
45 Oslo&lt;/a&gt;. The workshop to help people get started will take place
46 Thursday 2013-11-28, but we already are collecting the geolocation of
47 people joining forces to make this happen. We have
48 &lt;a href=&quot;https://github.com/petterreinholdtsen/meshfx-node/blob/master/oslo-nodes.geojson&quot;&gt;9
49 locations plotted on the map&lt;/a&gt;, but we will need more before we have
50 a connected mesh spread across Oslo. If this sound interesting to
51 you, please join us at the workshop. If you are too impatient to wait
52 15 days, please join us on the IRC channel
53 &lt;a href=&quot;irc://irc.freenode.net/%23nuug&quot;&gt;#nuug on irc.freenode.net&lt;/a&gt;
54 right away. :)&lt;/p&gt;
55 </description>
56 </item>
57
58 <item>
59 <title>Running TP-Link MR3040 as a batman-adv mesh node using openwrt</title>
60 <link>http://people.skolelinux.org/pere/blog/Running_TP_Link_MR3040_as_a_batman_adv_mesh_node_using_openwrt.html</link>
61 <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Running_TP_Link_MR3040_as_a_batman_adv_mesh_node_using_openwrt.html</guid>
62 <pubDate>Sun, 10 Nov 2013 23:00:00 +0100</pubDate>
63 <description>&lt;p&gt;Continuing my research into mesh networking, I was recommended to
64 use TP-Link 3040 and 3600 access points as mesh nodes, and the pair I
65 bought arrived on Friday. Here are my notes on how to set up the
66 MR3040 as a mesh node using
67 &lt;a href=&quot;http://www.openwrt.org/&quot;&gt;OpenWrt&lt;/a&gt;.&lt;/p&gt;
68
69 &lt;p&gt;I started by following the instructions on the OpenWRT wiki for
70 &lt;a href=&quot;http://wiki.openwrt.org/toh/tp-link/tl-mr3040&quot;&gt;TL-MR3040&lt;/a&gt;,
71 and downloaded
72 &lt;a href=&quot;http://downloads.openwrt.org/snapshots/trunk/ar71xx/openwrt-ar71xx-generic-tl-mr3040-v2-squashfs-factory.bin&quot;&gt;the
73 recommended firmware image&lt;/a&gt;
74 (openwrt-ar71xx-generic-tl-mr3040-v2-squashfs-factory.bin) and
75 uploaded it into the original web interface. The flashing went fine,
76 and the machine was available via telnet on the ethernet port. After
77 logging in and setting the root password, ssh was available and I
78 could start to set it up as a batman-adv mesh node.&lt;/p&gt;
79
80 &lt;p&gt;I started off by reading the instructions from
81 &lt;a href=&quot;http://wirelessafrica.meraka.org.za/wiki/index.php?title=Antoine&#39;s_Research&quot;&gt;Wireless
82 Africa&lt;/a&gt;, which had quite a lot of useful information, but
83 eventually I followed the recipe from the Open Mesh wiki for
84 &lt;a href=&quot;http://www.open-mesh.org/projects/batman-adv/wiki/Batman-adv-openwrt-config&quot;&gt;using
85 batman-adv on OpenWrt&lt;/a&gt;. A small snag was the fact that the
86 &lt;tt&gt;opkg install kmod-batman-adv&lt;/tt&gt; command did not work as it
87 should. The batman-adv kernel module would fail to load because its
88 dependency crc16 was not already loaded. I
89 &lt;a href=&quot;https://dev.openwrt.org/ticket/14452&quot;&gt;reported the bug&lt;/a&gt; to
90 the openwrt project and hope it will be fixed soon. But the problem
91 only seem to affect initial testing of batman-adv, as configuration
92 seem to work when booting from scratch.&lt;/p&gt;
93
94 &lt;p&gt;The setup is done using files in /etc/config/. I did not bridge
95 the Ethernet and mesh interfaces this time, to be able to hook up the
96 box on my local network and log into it for configuration updates.
97 The following files were changed and look like this after modifying
98 them:&lt;/p&gt;
99
100 &lt;p&gt;&lt;tt&gt;/etc/config/network&lt;/tt&gt;&lt;/p&gt;
101
102 &lt;pre&gt;
103
104 config interface &#39;loopback&#39;
105 option ifname &#39;lo&#39;
106 option proto &#39;static&#39;
107 option ipaddr &#39;127.0.0.1&#39;
108 option netmask &#39;255.0.0.0&#39;
109
110 config globals &#39;globals&#39;
111 option ula_prefix &#39;fdbf:4c12:3fed::/48&#39;
112
113 config interface &#39;lan&#39;
114 option ifname &#39;eth0&#39;
115 option type &#39;bridge&#39;
116 option proto &#39;dhcp&#39;
117 option ipaddr &#39;192.168.1.1&#39;
118 option netmask &#39;255.255.255.0&#39;
119 option hostname &#39;tl-mr3040&#39;
120 option ip6assign &#39;60&#39;
121
122 config interface &#39;mesh&#39;
123 option ifname &#39;adhoc0&#39;
124 option mtu &#39;1528&#39;
125 option proto &#39;batadv&#39;
126 option mesh &#39;bat0&#39;
127 &lt;/pre&gt;
128
129 &lt;p&gt;&lt;tt&gt;/etc/config/wireless&lt;/tt&gt;&lt;/p&gt;
130 &lt;pre&gt;
131
132 config wifi-device &#39;radio0&#39;
133 option type &#39;mac80211&#39;
134 option channel &#39;11&#39;
135 option hwmode &#39;11ng&#39;
136 option path &#39;platform/ar933x_wmac&#39;
137 option htmode &#39;HT20&#39;
138 list ht_capab &#39;SHORT-GI-20&#39;
139 list ht_capab &#39;SHORT-GI-40&#39;
140 list ht_capab &#39;RX-STBC1&#39;
141 list ht_capab &#39;DSSS_CCK-40&#39;
142 option disabled &#39;0&#39;
143
144 config wifi-iface &#39;wmesh&#39;
145 option device &#39;radio0&#39;
146 option ifname &#39;adhoc0&#39;
147 option network &#39;mesh&#39;
148 option encryption &#39;none&#39;
149 option mode &#39;adhoc&#39;
150 option bssid &#39;02:BA:00:00:00:01&#39;
151 option ssid &#39;meshfx@hackeriet&#39;
152 &lt;/pre&gt;
153 &lt;p&gt;&lt;tt&gt;/etc/config/batman-adv&lt;/tt&gt;&lt;/p&gt;
154 &lt;pre&gt;
155
156 config &#39;mesh&#39; &#39;bat0&#39;
157 option interfaces &#39;adhoc0&#39;
158 option &#39;aggregated_ogms&#39;
159 option &#39;ap_isolation&#39;
160 option &#39;bonding&#39;
161 option &#39;fragmentation&#39;
162 option &#39;gw_bandwidth&#39;
163 option &#39;gw_mode&#39;
164 option &#39;gw_sel_class&#39;
165 option &#39;log_level&#39;
166 option &#39;orig_interval&#39;
167 option &#39;vis_mode&#39;
168 option &#39;bridge_loop_avoidance&#39;
169 option &#39;distributed_arp_table&#39;
170 option &#39;network_coding&#39;
171 option &#39;hop_penalty&#39;
172
173 # yet another batX instance
174 # config &#39;mesh&#39; &#39;bat5&#39;
175 # option &#39;interfaces&#39; &#39;second_mesh&#39;
176 &lt;/pre&gt;
177
178 &lt;p&gt;The mesh node is now operational. I have yet to test its range,
179 but I hope it is good. I have not yet tested the TP-Link 3600 box
180 still wrapped up in plastic.&lt;/p&gt;
181 </description>
182 </item>
183
184 <item>
185 <title>Teaching vmdebootstrap to create Raspberry Pi SD card images</title>
186 <link>http://people.skolelinux.org/pere/blog/Teaching_vmdebootstrap_to_create_Raspberry_Pi_SD_card_images.html</link>
187 <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Teaching_vmdebootstrap_to_create_Raspberry_Pi_SD_card_images.html</guid>
188 <pubDate>Sun, 27 Oct 2013 17:00:00 +0100</pubDate>
189 <description>&lt;p&gt;The
190 &lt;a href=&quot;http://packages.qa.debian.org/v/vmdebootstrap.html&quot;&gt;vmdebootstrap&lt;/a&gt;
191 program is a a very nice system to create virtual machine images. It
192 create a image file, add a partition table, mount it and run
193 debootstrap in the mounted directory to create a Debian system on a
194 stick. Yesterday, I decided to try to teach it how to make images for
195 &lt;a href=&quot;https://wiki.debian.org/RaspberryPi&quot;&gt;Raspberry Pi&lt;/a&gt;, as part
196 of a plan to simplify the build system for
197 &lt;a href=&quot;https://wiki.debian.org/FreedomBox&quot;&gt;the FreedomBox
198 project&lt;/a&gt;. The FreedomBox project already uses vmdebootstrap for
199 the virtualbox images, but its current build system made multistrap
200 based system for Dreamplug images, and it is lacking support for
201 Raspberry Pi.&lt;/p&gt;
202
203 &lt;p&gt;Armed with the knowledge on how to build &quot;foreign&quot; (aka non-native
204 architecture) chroots for Raspberry Pi, I dived into the vmdebootstrap
205 code and adjusted it to be able to build armel images on my amd64
206 Debian laptop. I ended up giving vmdebootstrap five new options,
207 allowing me to replicate the image creation process I use to make
208 &lt;a href=&quot;http://people.skolelinux.org/pere/blog/A_Raspberry_Pi_based_batman_adv_Mesh_network_node.html&quot;&gt;Debian
209 Jessie based mesh node images for the Raspberry Pi&lt;/a&gt;. First, the
210 &lt;tt&gt;--foreign /path/to/binfm_handler&lt;/tt&gt; option tell vmdebootstrap to
211 call debootstrap with --foreign and to copy the handler into the
212 generated chroot before running the second stage. This allow
213 vmdebootstrap to create armel images on an amd64 host. Next I added
214 two new options &lt;tt&gt;--bootsize size&lt;/tt&gt; and &lt;tt&gt;--boottype
215 fstype&lt;/tt&gt; to teach it to create a separate /boot/ partition with the
216 given file system type, allowing me to create an image with a vfat
217 partition for the /boot/ stuff. I also added a &lt;tt&gt;--variant
218 variant&lt;/tt&gt; option to allow me to create smaller images without the
219 Debian base system packages installed. Finally, I added an option
220 &lt;tt&gt;--no-extlinux&lt;/tt&gt; to tell vmdebootstrap to not install extlinux
221 as a boot loader. It is not needed on the Raspberry Pi and probably
222 most other non-x86 architectures. The changes were accepted by the
223 upstream author of vmdebootstrap yesterday and today, and is now
224 available from
225 &lt;a href=&quot;http://git.liw.fi/cgi-bin/cgit/cgit.cgi/vmdebootstrap/&quot;&gt;the
226 upstream project page&lt;/a&gt;.&lt;/p&gt;
227
228 &lt;p&gt;To use it to build a Raspberry Pi image using Debian Jessie, first
229 create a small script (the customize script) to add the non-free
230 binary blob needed to boot the Raspberry Pi and the APT source
231 list:&lt;/p&gt;
232
233 &lt;p&gt;&lt;pre&gt;
234 #!/bin/sh
235 set -e # Exit on first error
236 rootdir=&quot;$1&quot;
237 cd &quot;$rootdir&quot;
238 cat &amp;lt;&amp;lt;EOF &gt; etc/apt/sources.list
239 deb http://http.debian.net/debian/ jessie main contrib non-free
240 EOF
241 # Install non-free binary blob needed to boot Raspberry Pi. This
242 # install a kernel somewhere too.
243 wget https://raw.github.com/Hexxeh/rpi-update/master/rpi-update \
244 -O $rootdir/usr/bin/rpi-update
245 chmod a+x $rootdir/usr/bin/rpi-update
246 mkdir -p $rootdir/lib/modules
247 touch $rootdir/boot/start.elf
248 chroot $rootdir rpi-update
249 &lt;/pre&gt;&lt;/p&gt;
250
251 &lt;p&gt;Next, fetch the latest vmdebootstrap script and call it like this
252 to build the image:&lt;/p&gt;
253
254 &lt;pre&gt;
255 sudo ./vmdebootstrap \
256 --variant minbase \
257 --arch armel \
258 --distribution jessie \
259 --mirror http://http.debian.net/debian \
260 --image test.img \
261 --size 600M \
262 --bootsize 64M \
263 --boottype vfat \
264 --log-level debug \
265 --verbose \
266 --no-kernel \
267 --no-extlinux \
268 --root-password raspberry \
269 --hostname raspberrypi \
270 --foreign /usr/bin/qemu-arm-static \
271 --customize `pwd`/customize \
272 --package netbase \
273 --package git-core \
274 --package binutils \
275 --package ca-certificates \
276 --package wget \
277 --package kmod
278 &lt;/pre&gt;&lt;/p&gt;
279
280 &lt;p&gt;The list of packages being installed are the ones needed by
281 rpi-update to make the image bootable on the Raspberry Pi, with the
282 exception of netbase, which is needed by debootstrap to find
283 /etc/hosts with the minbase variant. I really wish there was a way to
284 set up an Raspberry Pi using only packages in the Debian archive, but
285 that is not possible as far as I know, because it boots from the GPU
286 using a non-free binary blob.&lt;/p&gt;
287
288 &lt;p&gt;The build host need debootstrap, kpartx and qemu-user-static and
289 probably a few others installed. I have not checked the complete
290 build dependency list.&lt;/p&gt;
291
292 &lt;p&gt;The resulting image will not use the hardware floating point unit
293 on the Raspberry PI, because the armel architecture in Debian is not
294 optimized for that use. So the images created will be a bit slower
295 than &lt;a href=&quot;http://www.raspbian.org/&quot;&gt;Raspbian&lt;/a&gt; based images.&lt;/p&gt;
296 </description>
297 </item>
298
299 <item>
300 <title>A Raspberry Pi based batman-adv Mesh network node</title>
301 <link>http://people.skolelinux.org/pere/blog/A_Raspberry_Pi_based_batman_adv_Mesh_network_node.html</link>
302 <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/A_Raspberry_Pi_based_batman_adv_Mesh_network_node.html</guid>
303 <pubDate>Mon, 21 Oct 2013 11:40:00 +0200</pubDate>
304 <description>&lt;p&gt;The last few days I have been experimenting with
305 &lt;a href=&quot;http://www.open-mesh.org/projects/batman-adv/wiki&quot;&gt;the
306 batman-adv mesh technology&lt;/a&gt;. I want to gain some experience to see
307 if it will fit &lt;a href=&quot;https://wiki.debian.org/FreedomBox&quot;&gt;the
308 Freedombox project&lt;/a&gt;, and together with my neighbors try to build a
309 mesh network around the park where I live. Batman-adv is a layer 2
310 mesh system (&quot;ethernet&quot; in other words), where the mesh network appear
311 as if all the mesh clients are connected to the same switch.&lt;/p&gt;
312
313 &lt;p&gt;My hardware of choice was the Linksys WRT54GL routers I had lying
314 around, but I&#39;ve been unable to get them working with batman-adv. So
315 instead, I started playing with a
316 &lt;a href=&quot;http://www.raspberrypi.org/&quot;&gt;Raspberry Pi&lt;/a&gt;, and tried to
317 get it working as a mesh node. My idea is to use it to create a mesh
318 node which function as a switch port, where everything connected to
319 the Raspberry Pi ethernet plug is connected (bridged) to the mesh
320 network. This allow me to hook a wifi base station like the Linksys
321 WRT54GL to the mesh by plugging it into a Raspberry Pi, and allow
322 non-mesh clients to hook up to the mesh. This in turn is useful for
323 Android phones using &lt;a href=&quot;http://servalproject.org/&quot;&gt;the Serval
324 Project&lt;/a&gt; voip client, allowing every one around the playground to
325 phone and message each other for free. The reason is that Android
326 phones do not see ad-hoc wifi networks (they are filtered away from
327 the GUI view), and can not join the mesh without being rooted. But if
328 they are connected using a normal wifi base station, they can talk to
329 every client on the local network.&lt;/p&gt;
330
331 &lt;p&gt;To get this working, I&#39;ve created a debian package
332 &lt;a href=&quot;https://github.com/petterreinholdtsen/meshfx-node&quot;&gt;meshfx-node&lt;/a&gt;
333 and a script
334 &lt;a href=&quot;https://github.com/petterreinholdtsen/meshfx-node/blob/master/build-rpi-mesh-node&quot;&gt;build-rpi-mesh-node&lt;/a&gt;
335 to create the Raspberry Pi boot image. I&#39;m using Debian Jessie (and
336 not Raspbian), to get more control over the packages available.
337 Unfortunately a huge binary blob need to be inserted into the boot
338 image to get it booting, but I&#39;ll ignore that for now. Also, as
339 Debian lack support for the CPU features available in the Raspberry
340 Pi, the system do not use the hardware floating point unit. I hope
341 the routing performance isn&#39;t affected by the lack of hardware FPU
342 support.&lt;/p&gt;
343
344 &lt;p&gt;To create an image, run the following with a sudo enabled user
345 after inserting the target SD card into the build machine:&lt;/p&gt;
346
347 &lt;p&gt;&lt;pre&gt;
348 % wget -O build-rpi-mesh-node \
349 https://raw.github.com/petterreinholdtsen/meshfx-node/master/build-rpi-mesh-node
350 % sudo bash -x ./build-rpi-mesh-node &gt; build.log 2&gt;&amp;1
351 % dd if=/root/rpi/rpi_basic_jessie_$(date +%Y%m%d).img of=/dev/mmcblk0 bs=1M
352 %
353 &lt;/pre&gt;&lt;/p&gt;
354
355 &lt;p&gt;Booting with the resulting SD card on a Raspberry PI with a USB
356 wifi card inserted should give you a mesh node. At least it does for
357 me with a the wifi card I am using. The default mesh settings are the
358 ones used by the Oslo mesh project at Hackeriet, as I mentioned in
359 &lt;a href=&quot;http://people.skolelinux.org/pere/blog/Oslo_community_mesh_network___with_NUUG_and_Hackeriet_at_Hausmania.html&quot;&gt;an
360 earlier blog post about this mesh testing&lt;/a&gt;.&lt;/p&gt;
361
362 &lt;p&gt;The mesh node was not horribly expensive either. I bought
363 everything over the counter in shops nearby. If I had ordered online
364 from the lowest bidder, the price should be significantly lower:&lt;/p&gt;
365
366 &lt;p&gt;&lt;table&gt;
367
368 &lt;tr&gt;&lt;th&gt;Supplier&lt;/th&gt;&lt;th&gt;Model&lt;/th&gt;&lt;th&gt;NOK&lt;/th&gt;&lt;/tr&gt;
369 &lt;tr&gt;&lt;td&gt;Teknikkmagasinet&lt;/td&gt;&lt;td&gt;Raspberry Pi model B&lt;/td&gt;&lt;td&gt;349.90&lt;/td&gt;&lt;/tr&gt;
370 &lt;tr&gt;&lt;td&gt;Teknikkmagasinet&lt;/td&gt;&lt;td&gt;Raspberry Pi type B case&lt;/td&gt;&lt;td&gt;99.90&lt;/td&gt;&lt;/tr&gt;
371 &lt;tr&gt;&lt;td&gt;Lefdal&lt;/td&gt;&lt;td&gt;Jensen Air:Link 25150&lt;/td&gt;&lt;td&gt;295.-&lt;/td&gt;&lt;/tr&gt;
372 &lt;tr&gt;&lt;td&gt;Clas Ohlson&lt;/td&gt;&lt;td&gt;Kingston 16 GB SD card&lt;/td&gt;&lt;td&gt;199.-&lt;/td&gt;&lt;/tr&gt;
373 &lt;tr&gt;&lt;td&gt;Total cost&lt;/td&gt;&lt;td&gt;&lt;/td&gt;&lt;td&gt;943.80&lt;/td&gt;&lt;/tr&gt;
374
375 &lt;/table&gt;&lt;/p&gt;
376
377 &lt;p&gt;Now my mesh network at home consist of one laptop in the basement
378 connected to my production network, one Raspberry Pi node on the 1th
379 floor that can be seen by my neighbor across the park, and one
380 play-node I use to develop the image building script. And some times
381 I hook up my work horse laptop to the mesh to test it. I look forward
382 to figuring out what kind of latency the batman-adv setup will give,
383 and how much packet loss we will experience around the park. :)&lt;/p&gt;
384 </description>
385 </item>
386
387 <item>
388 <title>Oslo community mesh network - with NUUG and Hackeriet at Hausmania</title>
389 <link>http://people.skolelinux.org/pere/blog/Oslo_community_mesh_network___with_NUUG_and_Hackeriet_at_Hausmania.html</link>
390 <guid isPermaLink="true">http://people.skolelinux.org/pere/blog/Oslo_community_mesh_network___with_NUUG_and_Hackeriet_at_Hausmania.html</guid>
391 <pubDate>Fri, 11 Oct 2013 14:10:00 +0200</pubDate>
392 <description>&lt;p&gt;Wireless mesh networks are self organising and self healing
393 networks that can be used to connect computers across small and large
394 areas, depending on the radio technology used. Normal wifi equipment
395 can be used to create home made radio networks, and there are several
396 successful examples like
397 &lt;a href=&quot;http://www.freifunk.net/&quot;&gt;Freifunk&lt;/a&gt; and
398 &lt;a href=&quot;http://www.awmn.net/&quot;&gt;Athens Wireless Metropolitan Network&lt;/a&gt;
399 (see
400 &lt;a href=&quot;http://en.wikipedia.org/wiki/List_of_wireless_community_networks_by_region#Greece&quot;&gt;wikipedia
401 for a large list&lt;/a&gt;) around the globe. To give you an idea how it
402 work, check out the nice overview of the Kiel Freifunk community which
403 can be seen from their
404 &lt;a href=&quot;http://freifunk.in-kiel.de/ffmap/nodes.html&quot;&gt;dynamically
405 updated node graph and map&lt;/a&gt;, where one can see how the mesh nodes
406 automatically handle routing and recover from nodes disappearing.
407 There is also a small community mesh network group in Oslo, Norway,
408 and that is the main topic of this blog post.&lt;/p&gt;
409
410 &lt;p&gt;I&#39;ve wanted to check out mesh networks for a while now, and hoped
411 to do it as part of my involvement with the &lt;a
412 href=&quot;http://www.nuug.no/&quot;&gt;NUUG member organisation&lt;/a&gt; community, and
413 my recent involvement in
414 &lt;a href=&quot;https://wiki.debian.org/FreedomBox&quot;&gt;the Freedombox project&lt;/a&gt;
415 finally lead me to give mesh networks some priority, as I suspect a
416 Freedombox should use mesh networks to connect neighbours and family
417 when possible, given that most communication between people are
418 between those nearby (as shown for example by research on Facebook
419 communication patterns). It also allow people to communicate without
420 any central hub to tap into for those that want to listen in on the
421 private communication of citizens, which have become more and more
422 important over the years.&lt;/p&gt;
423
424 &lt;p&gt;So far I have only been able to find one group of people in Oslo
425 working on community mesh networks, over at the hack space
426 &lt;a href=&quot;http://hackeriet.no/&quot;&gt;Hackeriet&lt;/a&gt; at Husmania. They seem to
427 have started with some Freifunk based effort using OLSR, called
428 &lt;a href=&quot;http://oslo.freifunk.net/index.php?title=Main_Page&quot;&gt;the Oslo
429 Freifunk project&lt;/a&gt;, but that effort is now dead and the people
430 behind it have moved on to a batman-adv based system called
431 &lt;a href=&quot;http://meshfx.org/trac&quot;&gt;meshfx&lt;/a&gt;. Unfortunately the wiki
432 site for the Oslo Freifunk project is no longer possible to update to
433 reflect this fact, so the old project page can&#39;t be updated to point to
434 the new project. A while back, the people at Hackeriet invited people
435 from the Freifunk community to Oslo to talk about mesh networks. I
436 came across this video where Hans Jørgen Lysglimt interview the
437 speakers about this talk (from
438 &lt;a href=&quot;https://www.youtube.com/watch?v=N2Kd7CLkhSY&quot;&gt;youtube&lt;/a&gt;):&lt;/p&gt;
439
440 &lt;p&gt;&lt;iframe width=&quot;420&quot; height=&quot;315&quot; src=&quot;https://www.youtube.com/embed/N2Kd7CLkhSY&quot; frameborder=&quot;0&quot; allowfullscreen&gt;&lt;/iframe&gt;&lt;/p&gt;
441
442 &lt;p&gt;I mentioned OLSR and batman-adv, which are mesh routing protocols.
443 There are heaps of different protocols, and I am still struggling to
444 figure out which one would be &quot;best&quot; for some definitions of best, but
445 given that the community mesh group in Oslo is so small, I believe it
446 is best to hook up with the existing one instead of trying to create a
447 completely different setup, and thus I have decided to focus on
448 batman-adv for now. It sure help me to know that the very cool
449 &lt;a href=&quot;http://www.servalproject.org/&quot;&gt;Serval project in Australia&lt;/a&gt;
450 is using batman-adv as their meshing technology when it create a self
451 organizing and self healing telephony system for disaster areas and
452 less industrialized communities. Check out this cool video presenting
453 that project (from
454 &lt;a href=&quot;https://www.youtube.com/watch?v=30qNfzJCQOA&quot;&gt;youtube&lt;/a&gt;):&lt;/p&gt;
455
456 &lt;p&gt;&lt;iframe width=&quot;560&quot; height=&quot;315&quot; src=&quot;https://www.youtube.com/embed/30qNfzJCQOA&quot; frameborder=&quot;0&quot; allowfullscreen&gt;&lt;/iframe&gt;&lt;/p&gt;
457
458 &lt;p&gt;According to the wikipedia page on
459 &lt;a href=&quot;http://en.wikipedia.org/wiki/Wireless_mesh_network&quot;&gt;Wireless
460 mesh network&lt;/a&gt; there are around 70 competing schemes for routing
461 packets across mesh networks, and OLSR, B.A.T.M.A.N. and
462 B.A.T.M.A.N. advanced are protocols used by several free software
463 based community mesh networks.&lt;/p&gt;
464
465 &lt;p&gt;The batman-adv protocol is a bit special, as it provide layer 2
466 (as in ethernet ) routing, allowing ipv4 and ipv6 to work on the same
467 network. One way to think about it is that it provide a mesh based
468 vlan you can bridge to or handle like any other vlan connected to your
469 computer. The required drivers are already in the Linux kernel at
470 least since Debian Wheezy, and it is fairly easy to set up. A
471 &lt;a href=&quot;http://www.open-mesh.org/projects/batman-adv/wiki/Quick-start-guide&quot;&gt;good
472 introduction&lt;/a&gt; is available from the Open Mesh project. These are
473 the key settings needed to join the Oslo meshfx network:&lt;/p&gt;
474
475 &lt;p&gt;&lt;table&gt;
476 &lt;tr&gt;&lt;th&gt;Setting&lt;/th&gt;&lt;th&gt;Value&lt;/th&gt;&lt;/tr&gt;
477 &lt;tr&gt;&lt;td&gt;Protocol / kernel module&lt;/td&gt;&lt;td&gt;batman-adv&lt;/td&gt;&lt;/tr&gt;
478 &lt;tr&gt;&lt;td&gt;ESSID&lt;/td&gt;&lt;td&gt;meshfx@hackeriet&lt;/td&gt;&lt;/tr&gt;
479 &lt;td&gt;Channel / Frequency&lt;/td&gt;&lt;td&gt;11 / 2462&lt;/td&gt;&lt;/tr&gt;
480 &lt;td&gt;Cell ID&lt;/td&gt;&lt;td&gt;02:BA:00:00:00:01&lt;/td&gt;
481 &lt;/table&gt;&lt;/p&gt;
482
483 &lt;p&gt;The reason for setting ad-hoc wifi Cell ID is to work around bugs
484 in firmware used in wifi card and wifi drivers. (See a nice post from
485 VillageTelco about
486 &quot;&lt;a href=&quot;http://tiebing.blogspot.no/2009/12/ad-hoc-cell-splitting-re-post-original.html&quot;&gt;Information
487 about cell-id splitting, stuck beacons, and failed IBSS merges!&lt;/a&gt;
488 for details.) When these settings are activated and you have some
489 other mesh node nearby, your computer will be connected to the mesh
490 network and can communicate with any mesh node that is connected to
491 any of the nodes in your network of nodes. :)&lt;/p&gt;
492
493 &lt;p&gt;My initial plan was to reuse my old Linksys WRT54GL as a mesh node,
494 but that seem to be very hard, as I have not been able to locate a
495 firmware supporting batman-adv. If anyone know how to use that old
496 wifi access point with batman-adv these days, please let me know.&lt;/p&gt;
497
498 &lt;p&gt;If you find this project interesting and want to join, please join
499 us on IRC, either channel
500 &lt;a href=&quot;irc://irc.freenode.net/#oslohackerspace&quot;&gt;#oslohackerspace&lt;/a&gt;
501 or &lt;a href=&quot;irc://irc.freenode.net/#nuug&quot;&gt;#nuug&lt;/a&gt; on
502 irc.freenode.net.&lt;/p&gt;
503
504 &lt;p&gt;While investigating mesh networks in Oslo, I came across an old
505 research paper from the university of Stavanger and Telenor Research
506 and Innovation called
507 &lt;a href=&quot;http://folk.uio.no/paalee/publications/netrel-egeland-iswcs-2008.pdf&quot;&gt;The
508 reliability of wireless backhaul mesh networks&lt;/a&gt; and elsewhere
509 learned that Telenor have been experimenting with mesh networks at
510 Grünerløkka in Oslo. So mesh networks are also interesting for
511 commercial companies, even though Telenor discovered that it was hard
512 to figure out a good business plan for mesh networking and as far as I
513 know have closed down the experiment. Perhaps Telenor or others would
514 be interested in a cooperation?&lt;/p&gt;
515
516 &lt;p&gt;&lt;strong&gt;Update 2013-10-12&lt;/strong&gt;: I was just
517 &lt;a href=&quot;http://lists.alioth.debian.org/pipermail/freedombox-discuss/2013-October/005900.html&quot;&gt;told
518 by the Serval project developers&lt;/a&gt; that they no longer use
519 batman-adv (but are compatible with it), but their own crypto based
520 mesh system.&lt;/p&gt;
521 </description>
522 </item>
523
524 </channel>
525 </rss>