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--- wireless_mesh [2014/10/18 12:19] – created samer
+++ wireless_mesh [2014/10/19 22:01] – [4- Configuring the Wireless Nodes with B.A.T.M.A.N] samer
@@ Line 5: / Line 5: @@
 ===== -- Hardware Requirements =====
+Mesh networking performance is directly related to the number of available radio channels. Particularly, a mesh node with one wireless LAN chipset is able to transmit and receive on a single channel. As a result, a wireless mesh network rarely can fully exploit the aggregate bandwidth available in the radio spectrum provisioned by the standards. For a scientific explanation of this problem, please refer to this [[http://www.ecsl.cs.sunysb.edu/multichannel/ | research team page]].
+In order to overcome this problem, we implement in this project low cost multi-channel mesh devices consisting of a wireless router with an additional WLAN adapter. A typical equipment list that can be used for implementing the project is presented in the following:
   * TP-Link [[http://www.tp-link.com/en/products/details/?model=TL-MR3020#spec | MR3020]] wireless router.
   * USB WLAN adapter based on the [[http://www.amazon.com/niceEshop-Wireless-802-11-Adapter-Antenna/dp/B008IZQCGK/ref=pd_bxgy_pc_img_y | Ralink RT5370]] chipset.
   * Raspberry Pi [[http://www.element14.com/community/community/raspberry-pi | Model B]].
-===== -- Software Requirements =====
+===== -- Installing the Wireless Nodes =====
+Make sure you have the [[http://downloads.openwrt.org/attitude_adjustment/12.09/ar71xx/generic/openwrt-ar71xx-generic-tl-mr3020-v1-squashfs-factory.bin | attitude adjustment]] release of OpenWRT on your TP-LINK MR3020. For more information on how to flash the firmware on your router and take basic control, please refer to [[makerfaire | this article]].
+Start by updating the package list and installing the necessary packages for the USB WLAN adapter.
+<code bash>
+root@MeshNode:~# opkg update
+root@MeshNode:~# opkg install kmod-rt2800-lib kmod-rt2800-usb kmod-rt2x00-lib kmod-rt2x00-usb
+</code>
-http://downloads.openwrt.org/attitude_adjustment/12.09/ar71xx/generic/openwrt-ar71xx-generic-tl-mr3020-v1-squashfs-factory.bin
+[{{ :mr3020-wifi-adapter.jpg?nolink&300 | Figure 1. MR3020 with WLAN adapter }}]
-opkg update
-opkg install kmod-rt2800-lib kmod-rt2800-usb kmod-rt2x00-lib kmod-rt2x00-usb
-root@OpenWrt:/# wifi detect
+Plug the WLAN adapter on the USB port of your routeur and verify that is detected:
+<code bash>
+root@MeshNode:~# wifi detect
 config wifi-device  radio2
         option type     mac80211
@@ Line 35: / Line 47: @@
         option ssid     OpenWrt
         option encryption none
+</code>
-wifi detect > /etc/config/wireless
-root@OpenWrt:/# vi /etc/config/wireless
+Now, copy the detected WiFi modules into the wireless configuration of your MR3020.
+<code bash>
+root@MeshNode:~# wifi detect > /etc/config/wireless
+</code>
+Your wireless configuration file should be similar to the following:
+<file autoconf /etc/config/wireless>
 config wifi-device  radio0
         option type     mac80211
@@ Line 74: / Line 92: @@
         option ssid     OpenWrt2
         option encryption none
+</file>
-root@OpenWrt:/# wifi up
+Check that both antennas are working:
+<code bash>
+root@MeshNode:~# wifi up
 Configuration file: /var/run/hostapd-phy0.conf
 Using interface wlan0 with hwaddr f8:d1:11:bd:62:ce and ssid "OpenWrt1"
 Configuration file: /var/run/hostapd-phy1.conf
 Using interface wlan1 with hwaddr 00:e0:4c:81:88:8a and ssid "OpenWrt2"
+</code>
+<WRAP info>
+The USB WLAN adapter does not seem to be supported in the latest Barrier Breaker relaease of OpenWRT. Additional packages are installed correctly but the adapter is not detected as a WLAN module.
+</WRAP>
+===== -- Configuring the Wireless Nodes with B.A.T.M.A.N=====
+Start by installing the B.A.T.M.A.N package on your router:
+<code bash>
+root@MeshNode:~# opkg install kmod-batman-adv
+</code>
+Modify your wireless configuration to activate a mesh interface in ad-hoc mode on radio0, an interface in AP mode on radio1, as in the following:
+<file autoconf /etc/config/wireless>
+config wifi-device 'radio0'
+      option type 'mac80211'
+      option macaddr 'f8:d1:11:bd:62:ce'
+      option hwmode '11ng'
+      option htmode 'HT20'
+      list ht_capab 'SHORT-GI-20'
+      list ht_capab 'SHORT-GI-40'
+      list ht_capab 'RX-STBC1'
+      list ht_capab 'DSSS_CCK-40'
+      option txpower '27'
+      option country 'US'
+      option channel '9'
+config wifi-iface 'wmesh'
+      option device 'radio0'
+        option mode 'adhoc'
+        option ssid 'mesh'
+        option encryption 'none'
+        option network 'mesh'
+        option ifname 'adhoc0'
+        option bssid 'f8:d1:11:bd:62:ce'
+config wifi-device 'radio1'
+      option type 'mac80211'
+      option channel '5'
+      option macaddr '00:e0:4c:81:88:8a'
+      option hwmode '11ng'
+      option htmode 'HT20'
+      list ht_capab 'GF'
+      list ht_capab 'SHORT-GI-20'
+      list ht_capab 'SHORT-GI-40'
+      list ht_capab 'RX-STBC1'
+config wifi-iface
+        option device 'radio1'
+        option mode 'ap'
+        option ssid 'tinode1'
+        option encryption 'none'
+        option network 'tinet'
+</file>
+<WRAP info>
+Very few USB WLAN adapters work in ad-hoc mode, thus it is preferable to configure the corresponding radio interface in AP mode and the internal chipset of the MR3020 router in ad-hoc mode.
+</WARP>
+Use the following network configuration:
+<file autoconf /etc/config/network>
+config interface 'loopback'
+      option ifname 'lo'
+      option proto 'static'
+      option ipaddr '127.0.0.1'
+      option netmask '255.0.0.0'
+config interface 'lan'
+      option type 'bridge'
+      option proto 'static'
+      option ipaddr '192.168.1.66'
+      option netmask '255.255.255.0'
+      option gateway '192.168.1.1'
+      list dns '192.168.1.1'
+      list dns '8.8.8.8'
+      option _orig_ifname 'eth0 wlan0 wlan1'
+      option _orig_bridge 'true'
+      option ifname 'eth0'
+config interface 'mesh'
+      option ifname 'adhoc0'
+      option mtu '1528'
+      option proto 'batadv'
+      option mesh 'bat0'
+config interface tinet
+      option ifname   bat0
+      option type     bridge
+      option proto    static
+      option ipaddr   11.11.11.1
+      option netmask  255.255.255.0
+</file>
+Make sure that ''bat0'' interface is declared in ''/etc/config/batman-adv'' as in the following:
+<file autoconf /etc/config/batman-adv>
+config 'mesh' 'bat0'
+      option 'interfaces' 'mesh'
+      option 'aggregated_ogms'
+      option 'ap_isolation'
+      option 'bonding'
+      option 'fragmentation'
+      option 'gw_bandwidth'
+      option 'gw_mode'
+      option 'gw_sel_class'
+      option 'log_level'
+      option 'orig_interval'
+      option 'vis_mode'
+      option 'bridge_loop_avoidance'
+</file>
+Activate the DHCP server on you acces point interface ''tinet'':
+<code bash>
+config dhcp
+      option start '100'
+      option leasetime '12h'
+      option limit '150'
+      option interface 'tinet'
+</code>
+Reboot your router, ...