9
Cisco Multiband In-Building Omnidirectional Ceiling-Mount Antenna (3G-ANTM1916-CM)
OL-12658-01
Installation Notes
Installation Notes
This antenna is designed to be mounted indoors on a suspended ceiling track having either flush or
recessed mounted ceiling tiles.
In addition to the antenna orientation, the installation location of the Cisco 3G wireless HWIC plays a
significant role in determining overall network performance with respect to all the wireless clients.
Clients at the farthest coverage points might have 10 to 50 percent of the bandwidth available to clients
close to the antenna. Wireless network coverage in one area or location might need to be lowered to
improve the performance for clients in other areas or locations.
Because antennas both transmit and receive radio signals, their performance can be adversely affected
by the surrounding environment, including physical obstructions or radio frequency (RF) interference.
Follow these guidelines to ensure the best possible performance:
•
Mount the antenna to use its propagation characteristics. For best results, mount the antenna
horizontally at ceiling level near the center of the coverage area.
Note
The antenna must be mounted horizontally in order to maximize its omnidirectional
propagation characteristics. Mounting it vertically may noticeably decrease the antenna
range and overall performance.
•
Wherever possible, mount the 3G wireless HWIC and antenna where the wireless devices are within
sight and without physical obstructions. Barriers along the line of sight between client and HWIC
will degrade the wireless radio signals. The Cisco 3G wireless HWICs and antennas can be installed
above floor level in office environments or near the ceiling for better performance, because most
obstructions tend to be near floor level.
•
The density of the materials used in a building’s construction determines the number of walls the
signal must pass through while still maintaining adequate coverage. Consider the following before
choosing the location for installing your antenna:
–
Paper and vinyl walls have very little effect on signal penetration.
–
Solid and precast concrete walls limit signal penetration to one or two walls without degradation
of coverage.
–
Concrete and wood block walls limit signal penetration to three or four walls.
–
A signal can penetrate five or six walls constructed of drywall or wood.
–
A thick metal wall or wire-mesh stucco wall causes signals to reflect back and causes poor
penetration.
•
Avoid mounting the antenna next to a column or vertical support that could create a shadow zone
and reduce the coverage area.
•
Keep the antenna away from reflective metal objects such as heating and air-conditioning ducts,
large ceiling trusses, building superstructures, and major power cabling runs. If necessary, use an
extension cable to relocate the antenna away from these obstructions.
Caution
Install the HWIC and any antennas away from appliances that share the same frequency bands.
Microwave ovens, cordless telephones, and security monitors can temporarily interfere with wireless
performance.
