Siemens SCALANCE W788-1PRO Operating Instructions Manual page 263

Transmit Power in IEEE 802.11g Mode (2.4 GHz)
Transmit Power in IEEE 802.11a/h Mode (5 GHz)
Specifying Power in dBi
If power is specified in dBi, the reference variable is the transmit power of an
isotropic antenna or unipole. Such a (hypothetical) antenna radiates energy from a
central point uniformly in all directions.
From the directional radiation of a real antenna, a dBi value is obtained known as
the antenna gain. This term is misleading in as far as no energy is gained by an
antenna in the physical sense. The higher radiation of a passive antenna results
solely from the concentration of radiation in a certain direction. In other spatial
segments, there is accordingly less power.
Operating Instructions SCALANCE W78x
C79000-G8976-C184-07
Data rate [Mb/s]
6
9
12
18
24
36
48
54
Data rate [Mb/s]
6
9
12
18
24
36
48
54
Appendix
P 0 [dBm]
17
17
17
17
17
13
11
10
P 0 [dBm]
17
17
17
17
17
13
11
10
263