Avaya AP-4 User Manual page 367

Radio Specifications
In Open Office environments, antennas can "see" each other (no physical
obstructions between them). In Semi-open Office environments,
workspace is divided by shoulder-height, hollow wall elements; antennas
are at desktop level. In a Closed Office environment, solid walls and other
obstructions may affect signal strength.
The following tables show typical range values for various environments
for FCC-certified products (range may differ for products certified in
other regulatory domains).
Avaya Wireless AP-4/AP-5 User's Guide C-9