Additional information
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45
Calculation for 2.4 GHz: free space attenuation [dB] = 100 + 20log distance [km]
4.1.4
Propagation of the radio wave indoors
4.1.4.1
In an industrial hall
If the wireless unit is installed in an industrial hall, the conditions listed above basically apply.
The Fresnel zone will not be free there. However reflections on metal objects may promote
the propagation of radio waves.
The range of the wireless modules depends on their mounting location and/or the position
of their antennas.
In general the antenna should be free from other objects, so it can radiate well into the area.
It should, for example, not be touched by cables or be surrounded by a metal control
cabinet.
The reference value for the range within an industrial hall is up to 50 meters. The actual
range may considerably exceed or fall below this value. This variation depends on the
environment and the transmission power set. Large metal obstacles, such as walls or
machines, may limit the range in that direction. This is particularly true if they are
permanently located (static) between the wireless units.
The range can be limited by reducing the transmission power. Thus, only certain areas can
be covered, if desired.
A more exact estimation of the range can also be achieved by prior simulation. The
influence of the environment is then also taken into consideration. To do so, use the
350
90.9 dB
400
92.0 dB
450
93.1 dB
500
94.0 dB
550
94.8 dB
600
95.6 dB
650
96.3 dB
700
96.9 dB
750
97.5 dB
800
98.1 dB
850
98.6 dB
900
99.1 dB
950
99.6 dB
1000
100.0 dB
Table 4-2
Free space attenuation at 2.4 GHz
Distance in m
Attenuation at 2.4 GHz