GE GFK-2489 - Manual (Page 136)

GFK-2489 Chapter 6 Installation 6-3
6
Site Selection
Suitable installation sites should provide:
▪ Protection from direct weather exposure
▪ A source of adequate and stable primary power
▪ Suitable entrances for antenna, interface or other required cabling
▪ Antenna location that provides as unobstructed a transmission path as possible in the
direction of the associated station(s)
These requirements can be quickly determined in most cases. A possible exception is the last
item—verifying that an unobstructed transmission path exists. Radio signals travel primarily
by line of sight, and obstructions between the sending and receiving stations affect system
performance. If you are not familiar with the effects of terrain and other obstructions on radio
transmission, the discussion below provides helpful background.
Conducting a Site Survey
If you are in doubt about the suitability of the radio sites in your system, it is best to evaluate
them before a permanent installation is begun. This can be done with an on-the-air test (the
preferred method); or indirectly, using path-study software.
An on-the-air test is preferred because it allows you to see firsthand the factors involved at an
installation site and to directly observe the quality of system operation. Even if a computer
path study was conducted earlier, this test should be done to verify the predicted results.
The test can be performed by first installing a radio and antenna at the proposed AP station
site (one per system). Then visit the remote site(s) with a transceiver and a hand-held
antenna. (A PC with a network adapter can be connected to each radio in the network to
simulate data during this test using the
PING
command.)
With the hand-held antenna positioned near the proposed mounting spot, a technician can
check for synchronization with the AP station (shown by a lit LINK LED on the front panel) and
measure the reported RSSI value using the
RADIO RSSI=
command. If adequate signal
strength cannot be obtained, it may be necessary to mount the station antennas higher, use
higher gain antennas, select a different site, or consider installing a repeater station.