AirLive WHB-5854A - Manual (Page 43)

AirLive WHB-5854A Wireless Outdoor Bridge
43
For example, the wireless link between the building A and the building B
is located three miles (4.8 km) away. There is a tree-covered hill in the
mid-way. From the table above, it can be seen that for a three-mile link and
the object clearance required at the mid-point is 5.4 m (17.6 ft). The
tree-covered hill height is at an elevation of 17 m (56 ft), so the antennas
linkage on both sides need to be at least 22.4 m (73 ft) high. The building A
is six stories high or 20 m (66 ft), so the mast or pole with 2.4 m (7.9 ft) must
be constructed on its roof to meet the required antenna height. The building
B is only three stories high or 9 m (30 ft) but it is located at an elevation that is
12 m (39 ft) higher than the building A. A mast or pole is required to mount
an antenna at the required height 1.4 m(4.6ft) on the roof of building B.
6.3.2 ANTENNA TYPES
Each antenna must have the FCC-approved for use with the bridge.
The antennas provide omnidirectional, directional, or diverse coverage and
support various communication distances. Antennas are available with
different gain ratings and coverage areas. The following figure is to show
you one of these combinations, for example; the Bridge comes with the
omnidirectional Antenna.
Picture 26 The Bridge with the omnidirectional antenna
6.3.3 Antenna Cable
An antenna cable introduces signal losses in the antenna system for
both the transmitter and receiver. To reduce signal loss, you should
minimize the cable length and use only low-loss antenna cable to connect
your radio device to the antenna.