A closed room environment is viewed as a lossy cavity,
characterized by possibly a line of sight (LOS) component and
diffuse scattering parts from walls and internal obstacles. A theory
used in acoustics and reverberation chambers is applied for the
electromagnetics case, and main issues related to measurement
systems and antennas characteristics are discussed. The goal of this
paper is the assessment of the reverberation time in an environment
with different measurement systems. From the reverberation time
one can derive the absorption area and hence the absorption cross
section for humans in realistic environments.