openwifi/doc/app_notes/ap-client-two-sdr.md

NOTE the terminal session mentioned in the following text can also be setup via USB-UART instead of Ethernet.

• Power on two SDR boards. Call one board "AP board" and the other "client board". On each board, the TX and RX antenna should vertical/orthogonal to each other as much as possible to gain a good TX/RX isolation.

• Connect a computer to the AP board via Ethernet cable. The computer should have static IP 192.168.10.1. Open a terminal on the computer, and then in the terminal:

  ssh root@192.168.10.122
  (password: openwifi)
  cd openwifi
  ./fosdem.sh
  (It will create a WiFi AP by hostapd program with config file: hostapd-openwifi.conf)
  (Wait for the script completed)
  cat /proc/interrupts
  (Execute the "cat ..." command for several times)
  (You should see the number of "sdr,tx_itrpt1" grows, because it sends the "openwifi" beacon periodically)
  

• Connect another computer to the client board via Ethernet cable. The computer should have static IP 192.168.10.1. Open a terminal on the computer, and then in the terminal:

  ssh root@192.168.10.122
  (password: openwifi)
  service network-manager stop
  cd openwifi
  ./wgd.sh
  (Wait for the script completed)
  ifconfig sdr0 up
  iwlist sdr0 scan
  (The "openwifi" AP should be listed in the scanning results)
  wpa_supplicant -i sdr0 -c wpa-openwifi.conf
  

  If wpa-openwifi.conf is not on board, please create it with this content.

• Now the client is trying to associate with the AP. You should see like:

  root@analog:~/openwifi# wpa_supplicant -i sdr0 -c wpa-openwifi.conf 
  Successfully initialized wpa_supplicant
  sdr0: CTRL-EVENT-SCAN-STARTED 
  sdr0: SME: Trying to authenticate with 66:55:44:33:22:8c (SSID='openwifi' freq=5220 MHz)
  sdr0: Trying to associate with 66:55:44:33:22:8c (SSID='openwifi' freq=5220 MHz)
  sdr0: Associated with 66:55:44:33:22:8c
  sdr0: CTRL-EVENT-CONNECTED - Connection to 66:55:44:33:22:8c completed [id=0 id_str=]
  

  The AP board terminal should print like:

  ...
  sdr0: STA 66:55:44:33:22:4c IEEE 802.11: authenticated
  sdr0: STA 66:55:44:33:22:4c IEEE 802.11: associated (aid 1)
  sdr0: AP-STA-CONNECTED 66:55:44:33:22:4c
  sdr0: STA 66:55:44:33:22:4c RADIUS: starting accounting session 613E16DE-00000000
  

  If not, please adjust antenna/distance and re-run the commands on the client side.

• After association is done, in another terminal of client (DO NOT terminate wpa_supplicant in the original client terminal!):

  dhclient sdr0
  (Wait for it completed)
  ifconfig sdr0
  (Now you should see the IP address like 192.168.13.x allocated by AP)
  ping 192.168.13.1
  (Ping the AP)
  

  Now the communication link should be already setup between the AP and the client.