The 802.11 protocol type of the client.
'dot11a' - The client is using 802.11a standard
to connect to the access point (AP)
'dot11b' - The client is using 802.11b standard
to connect to the access point (AP)
'dot11g' - The client is using 802.11g standard
to connect to the access point (AP)
'dot11n5' - The client is using 802.11n standard
with 5 GHz frequency to connect to
the access point (AP).
'dot11n24' - The client is using 802.11n standard
with 2.4 GHz frequency to connect to
the access point (AP)