The range of your wireless devices can be affected when the
antennas are placed near metal surfaces and solid high-
density materials.
Range is also impacted due to "obstacles" in the signal path
of the radio that may either absorb or reflect the radio signal.
The listed ranges are typical values when used indoors in
"office environments" that can be described as follows:
In Open Office environments, antennas can "see" each
other, i.e. there are no physical obstructions between
them.
In Semi-open Office environments, work space is
divided by shoulder-height, hollow wall elements;
antennas are at desktop level.
In Closed Office environments, work space is separated
by floor-to-ceiling brick walls.
Card Specifications A-7