To scan for available wireless networks in your environment, use the scan() method. It takes the network interface name as only parameter and returns an array of Net_Wifi_Cell objects.

You get an array of local wireless interfaces via the getSupportedInterfaces() method.

A cell object looks like this:

Net_Wifi_Cell {
  cell      => string(2) "01"
  mac       => string(17) "00:03:C9:44:34:2C"
  ssid      => string(8) "<hidden>"
  mode      => string(6) "master"
  channel   => int(1)
  encryption=> bool(false)
  frequency => NULL
  protocol  => string(13) "IEEE 802.11bg"
  rate      => float(54)
  rates     => array(12) {
    0   => float(1)
    1   => float(2)
    2   => float(5.5)
    3   => float(6)
  }
  rssi      => string(3) "-39"
  beacon    => int(336)
  quality   => string(6) "90/100"
}