AirLive WHB-5854A - Manual (Page 40)

AirLive WHB-5854A Wireless Outdoor Bridge
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6.2 Data Rate
According to the following table, you will have the idea about over what range the
AirLive WHB-5854a with what kind of antenna could operate under what data rate.
You might also know the relationship between the data rate and the maximum radio
range; for example, the bridge with 17dBi antenna could operate well under 6 Mbps
data rate within 17 KM.
Data Rate Maximum Distance
(17dBi Antenna)
Maximum Distance
(23dBi Antenna)
6 Mbps 17.72 KM 30.79KM
9 Mbps 16.82KM 29.36 KM
12 Mbps 16.07KM 28.07 KM
18 Mbps 14.64KM 25.60 KM
24 Mbps 11.66 KM 20.26 KM
36 Mbps 8.21 KM 16.85 KM
48 Mbps 3.72KM 12.23 KM
54 Mbps 1.84 KM 7.32 KM
Table 1 Evaluated Maximum Distance
6.3 Planning Radio Path
For the wireless communication, the Line-of-Sight (LOS) will be the major issue
over building up the wireless link. This evaluated procedure is to reduce the
obstructions and to avoid the multiple-path signal degrading the communication
quality.
The first requirement is the Line-of-Sight (LOS) between the both sides ’
Antennas. The radio line-of-sight concept is the area along the radio linking path
through which is the bulk of the radio signal power travels. The area is known as
the first Fresnel Zone of the radio link. For the radio link, it should avoid to be
affected by obstacles in this path, including the ground within 60% of the first
Fresnel Zone.
The following figure illustrates the concept of a good radio line-of-sight.