wireless: rewrite chapter

- Update examples on Wireless Acceess-Point (WAP)
- Add example on Wireless Station (Wi-Fi client)

docs/interfaces/wireless.rst

@@ -1,29 +1,58 @@
+.. _wireless:
+
 Wireless Interfaces
 -------------------
-.. _interfaces-wireless:
 
-Wireless, for example WiFi 802.11 b/g/n, interfaces allow for connection to
-WiFi networks or act as an access-point.
-If your device is configurable it will appear as `wlan` in `show interfaces`.
+:abbr:`WLAN (Wireless LAN)` interface provide 802.11 (a/b/g/n/ac) wireless
+support (commonly referred to as Wi-Fi) by means of compatible hardware. If your
+hardware supports it, VyOS supports multiple logical wireless interfaces per
+physical device.
+
+There are three modes of operation for a wireless interface:
+
+* :abbr:`WAP (Wireless Access-Point)` provides network access to connecting
+  stations if the physical hardware supports acting as a WAP
+  
+* A station acts as a Wi-Fi client accessing the network through an available
+  WAP
+
+* Monitor, the system passively monitors any kind of wireless traffic
+
+If the system detects an unconfigured wireless device, it will be automatically
+added the configuration tree, specifying any detected settings (for example,
+its MAC address) and configured to run in monitor mode.
 
 To be able to use the wireless interfaces you will first need to set a
 regulatory domain with the country code of your locaion.
 
-.. code-block:: sh
+.. option:: set system wifi-regulatory-domain DE
 
-  set system wifi-regulatory-domain SE
+   Configure system wide Wi-Fi regulatory domain. A reboot is required for this
+   change to be enabled.   
 
-An example on how to set it up as an access point:
+Configuring Access-Point
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+The following example creates a WAP. When configuring multiple WAP interfaces,
+you must specify unique IP addresses, channels, Network IDs commonly refered
+to as :addr:`SSID (Service Set Identifier), and MAC addresses.
+
+The WAP in this example has the following characteristics:
+* IP address ``192.0.2.1/24``
+* Network ID (SSID) ``TEST``
+* WPA passphrase ``12345678``
+* Use 802.11n protocol
+* Wireless channel ``1``
 
 .. code-block:: sh
 
-  set interfaces wireless wlan0 address '192.168.99.1/24'
+  set interfaces wireless wlan0 address '192.0.2.1/24'
   set interfaces wireless wlan0 type access-point
   set interfaces wireless wlan0 channel 1
-  set interfaces wireless wlan0 ssid '<your ssid>'
+  set interfaces wireless wlan0 ssid 'TEST'
   set interfaces wireless wlan0 security wpa mode wpa2
   set interfaces wireless wlan0 security wpa cipher CCMP
-  set interfaces wireless wlan0 security wpa passphrase '<your passphrase>'
+  set interfaces wireless wlan0 security wpa passphrase '12345678'
 
 Resulting in
 
@@ -32,24 +61,57 @@ Resulting in
   interfaces {
     [...]
     wireless wlan0 {
-          address 192.168.99.1/24
+          address 192.0.2.1/24
           channel 1
           mode g
           security {
               wpa {
                   cipher CCMP
                   mode wpa2
-                  passphrase "<your passphrase>"
+                  passphrase "12345678"
               }
           }
-          ssid "<your ssid>"
+          ssid "TEST"
           type access-point
       }
   }
   system {
     [...]
-    wifi-regulatory-domain SE
+    wifi-regulatory-domain DE
   }
 
 To get it to work as a access point with this configuration you will need
-to set up a DHCP server to work with that network.
+to set up a DHCP server to work with that network. You can - of course - also
+bridge the Wireless interface with any configured bridge (:ref:`bridge`) on
+the system.
+
+Configuring Wireless Station
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The example creates a wireless station (commonly referred to as Wi-Fi client)
+that accesses the network through the WAP defined in the above example. The
+default physical device (``phy0``) is used.
+
+.. code-block:: sh
+
+  set interfaces wireless wlan0 type station
+  set interfaces wireless wlan0 address dhcp
+  set interfaces wireless wlan0 ssid Test
+  set interfaces wireless wlan0 security wpa
+
+Resulting in
+
+.. code-block:: sh
+
+  interfaces {
+    [...]
+    wireless wlan0 {
+      address dhcp
+      security {
+        wpa {
+          passphrase "12345678"
+        }
+      }
+      ssid TEST
+      type station
+	}