A17.5.6 Indoor-outdoor propagation

The use of the spherical diffraction model for indoor-outdoor propagation introduces the following additional terms

Median path loss

The median path loss is increased by the attenuation due to external walls (L_ew):

Variation in path loss

Variation in path loss is already taken into account in the SD model, through the calculation of the equivalent earth radius. Thus additional variation due to uncertainty concerning materials and relative location of the transmitter and receiver is reflected by an additional lognormal distribution trial using the above defined s_add.