Access5830™ User Manual
19
Site Selection
Proper site selection for your AP will help ensure a successful deployment. Site selection will depend on a
wide variety of factors, but from the radio’s performance standpoint, please consider the following:
•
Path from AP to SU should provide unobstructed line-of-sight, thus it is advisable to place AP as
high as possible on a tall building or tower.
•
Ethernet cable limit is 100 M from Ethernet device (router, switch) to radio.
•
Radios require grounding for optimal performance
•
AP provides sector coverage of 60 degrees.
•
Consider nearby sources of interference that could degrade performance of radio. Mount radios as
far from sources of interference as possible.
Site Survey
Both the AP and SU provide a powerful on-board site survey tool. This tool will tell you if there is
interference present in the 5.8 GHz or 5.3 GHz band.
The survey command is accessible from the Telnet command line in both the AP and SU. In order to use
the survey command, the radio must be in opmode “OFF”. The survey can be performed for any specified
amount of time (in seconds) and for either the horizontal or vertical polarization.
Prior to performing the site survey, place the radio in the installation spot, and aim the radio in the desired
direction.
An example of the site survey command is as follows:
ssurvey 30 h
This command will perform the site survey for 30 seconds for the horizontal polarization.
After the specified period, the results of this command will provide you with a listing of each frequency
within the band (in 2 Mhz increments), the average signal received, and the maximum signal received
during the survey period.
In general you will be looking for frequencies with signal strength of –85 dBm or lower. If interference is
present on various channels, it is recommended that you chose clean channels or alternate polarizations for
your deployment. If it is not possible to use a clean channel/polarization combination, there are various
methods available to mitigate the affects of interference. These methods include the use of the RFRX
THRESHOLD settings, or the use of external shields on the AP
Channel Planning
For installations involving co-location of APs, channel planning is of paramount importance. For
maximum AP co-location quantities, it is important to assign frequencies of maximum spacing and
alternating polarizations for adjacent APs. Use of the 5.3 spectrum as well as the 5.8 spectrum will allow
maximum co-location potential. For very dense deployments of multiple APs, it may be necessary to use
the optional AP Shielding kit in order to mitigate interference from nearby APs.
Various AP channel plans can be implemented and many of the factors will depend on the unique
circumstances at each particular site. See
www.trangobroadband.com
for additional information on
channel planning schemes.