Building Penetration Loss

The building penetration loss is the power attenuation that an electromagnetic wave undergoes as it propagates from outside a building towards one or several places inside this building. This parameter is generally calculated by comparing the external field and the field present in different parts of the building where the receiver is located.

The value of the building penetration loss is influenced by a number of different physical parameters, whose effects intermingle most of the time. Among these different parameters the following are traditionally distinguished:

- the near environment : a distinction is drawn between districts with high towers more or less separated from each other and more traditional districts with buildings of average height,

- the reception depth in buildings: the amplitude of the field decreases as the mobile moves from the front of the building towards a room located inside it, while the influence of the inhomogeneities decreases as the penetration depth inside a building increases. Waves penetrate more easily through window panes than through brick walls. Accordingly, the paths followed by radio waves will be more or less attenuated, and might even be occulted.

- the incidence angle, which determines the reflection and transmission coefficients at a surface,

- the frequency,

- the nature of the materials : Table 6.1 presents numerical values of the attenuation of electromagnetic waves obtained for different types of materials at the 17 and 60 GHz frequencies and in horizontal (H) and vertical (V) polarisations respectively (Fiacco 1998). Further detail on this subject can be found in the final report by the RACE Mobile Broadband System project (RACE-MBS R2067 1999).

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