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

• 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)
  iwconfig sdr0 essid openwifi
  

• Now the client is trying to associate with the AP. The AP board terminal should print like:

  ...
  sdr0: AP-STA-CONNECTED 66:55:44:33:22:58
  sdr0: STA 66:55:44:33:22:58 RADIUS: starting accounting session 1FF1C1B4-00000001
  

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

• After association is done, in the terminal of client:

  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.