This flag indicates whether the 802.11 interface is
connected to an external antenna and/or the attenuator
and configured with the resultant gain or not.
If the interface has an external antenna and/or an
attenuator connected to it and has been configured
with the resultant gain, the value of this object
is 'true'.
This object, when 'false', indicates that both the
external antenna and the attenuator are physically
disconnected from the 802.11 interface. Also,
the query to the object cDot11AntennaResultantGain
returns the default gain corresponding to the PHY
type of that 802.11 interface when this object's
value is 'false'.