Retrive. mac addresses of availble hot spots

Hello,

I am developing a locator device. On of its' required features is to be able to locate the device indoors using an online service that accepts a list of availble SSID in your area with their signal strength and MAC addresses.

Looking at the WiFi library I only see an option to retrive the SSID of the availble router.

Is there a diffrent library/shield or am I missing some feature?

Thanks alot Roman

For example:
The RX NV 171 module, as described in its’ datashhet:

2.6.14 scan
This command performs an active probe scan of access points on all 13 channels, where is an optional parameter representing the time in ms per channel. represents the optional parameter P, which causes the module to perform a passive scan, and list all access points it can see in passive mode. When you use this command, the module returns the MAC address, signal strength, SSID name, and security mode of the access points it finds.

Arduino Yun list nearby of access points' Address, Channel, signal strength as well ESSID.

iwlist wlan0 scan |grep 'Address:\|Channel:\|Quality\|ESSID'
Cell 01 - Address: 40:70:09:3F:A7:50
                    Channel:6
                    Quality=53/70  Signal level=-57 dBm
                    ESSID:"TG1672G52"
Cell 02 - Address: D8:50:E6:D7:EA:1E
                    Channel:8
                    Quality=70/70  Signal level=-20 dBm
                    ESSID:"ASUS"
...

http://forum.arduino.cc/index.php?topic=220440.msg1604651#msg1604651