Differences

This shows you the differences between two versions of the page.

--- wireless_mesh [2014/10/18 12:19] – created samer
+++ wireless_mesh [2014/10/19 22:03] (current) – [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>
+Due to the compatibility problems of the USB WLAN adapters, it is preferable to configure the corresponding radio interface in AP mode and leave the internal chipset of the MR3020 router in ad-hoc mode.
+</WRAP>
+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, ...