Indoor reception

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Under indoor reception is understood to mean the reception of radio services , such as mobile or broadcasting - and television programs within buildings (engl. Indoor ) using the self-existing in the device antennas .

The frequency-dependent attenuation on the radio signal by building components leads to lower signal field strengths within buildings. The building attenuation with indoor reception is taken into account as an additional summand in the power transmission balance . Typical attenuation values ​​at frequencies around 400  MHz are 10  dB for loose buildings and 20 dB for dense buildings. Concrete and precise values ​​depend heavily on the building materials used and the local conditions. In the case of complex building structures, the various influences for indoor reception can be shown in detailed supply plans; the field strength is recorded using special measuring receivers . In the building plan, the specific reception field strength is graphically displayed for each room and floor using various colors or numerical values. Wherever indoor reception is possible, outdoor reception is therefore always possible - except in rare special cases.

In the case of mobile communications, providers use the term network coverage to be able to make predictions where the reception conditions are still sufficient for the operation of the end device. Since the reception conditions in buildings are significantly worse, a distinction is made between outdoor network coverage, i.e. sufficient signal quality outdoors, and indoor network coverage when specifying the network coverage . As a rule, the forecast of indoor network coverage is not based on detailed measurements within buildings; instead, flat-rate and averaged attenuation values ​​are used for the signal strength in relation to the open space.

Where indoor reception is not possible, repeaters that require approval may be used, depending on the radio service . The areas of application here include cellular networks . Repeaters receive the signals in the outdoor area and forward them specifically to individual rooms in the building; analogously, signals from the indoor area are forwarded to the outdoor area via the repeater. In the case of digital broadcasting, the connection of an additional antenna is possible if an external antenna can be connected to the device. Indoor reception of satellite signals such as DVB-S is not uninterrupted due to the attenuation values ​​of conventional buildings and is therefore practically impossible. Contrary to various publications to the contrary, this also applies to signals from GPS satellites.

When operating local radio networks such as WLAN , outdoor reception , i.e. on the balcony or in the garden, is usually the problematic reception situation because the transmitter is located inside the building.

Web links

Individual evidence

  1. ↑ Radio network planning Tetron digital radio. Teron GmbH, company publication, accessed on March 7, 2014 .
  2. ↑ a b Thomas Riegler: Satellite reception behind glass: requirements for reception. In: DIGITAL television. Auerbach Verlag und Infodienste GmbH, Leipzig, July 27, 2011, accessed on March 6, 2014 (German).