Cisco Catalyst IR8140 Heavy Duty Series Hardware Installation Manual page 68

Antenna Installation Best Practices
Follow these guidelines to ensure the best possible performance:
• Keep antennas away from electrical and signal cable clutter. Metal conductors inside cables may block
antenna view of the base station. Additionally, unshielded (and even shielded cables in some cases) may
radiate signals that interfere with RF signal reception.
• It is recommended that all cellular antennas for the IR8140H are oriented vertically to ensure polarization
match. While polarization of the signal may change as it is reflected from obstructions, when the view
is unobstructed - vertical polarization is optimal.
• For a deployment with both WPAN module and LTE/5G module, you must choose IRMH-LTEA-EA-900
or IRMH-LTE-MNA-900 (with 900MHz WPAN co-existence filter) as the LTE/5G module. It is
recommended that you install the LTE/5G module in UIM slot 3 when the WPAN module is installed
in slot 1. For module slot locations, see
when using the antenna ANT-5G-MP-OUT-N on both WPAN and LTE modules.
For increased isolation and better WPAN/LTE performance, you can choose 10ft cables and either
ANT-5G-OMNI-OUT-N or any of the available multi-element antenna solutions (for example,
ANT-4-5G4-O).
• For optimal MIMO performance, space cellular Main and Aux antennas apart by at least 17 inches (43
cm). At the lowest LTE frequency of 700 MHz, 17 inches represents 1 wavelength. Spacing of half (or
0.5) wavelength or 8.5 inch (22.5cm) results in good MIMO performance.
• Spacing Main and Aux LTE antennas less than 8.5 inches may result in significantly reduced MIMO
performance.
• Spacing antennas too close to each other (e.g. 3 inches) results in antennas significantly detuning from
their original designed performance due to increased antenna coupling.
• Wherever possible, mount the IR8140H router with the UIM module and antenna where the cellular base
station or tower are within sight and without physical obstructions. Barriers along the line of sight between
the router and the local base station will degrade the wireless radio signals. Install the IR8140H, UIM
modules and antennas above floor level in office environments or near the ceiling for better performance
because most obstructions tend to be near the 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 the 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
• 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
• Avoid mounting the antenna next to a column or vertical support that could create a shadow zone and
reduce the coverage area.
Cisco Catalyst IR8140 Heavy Duty Series Router Hardware Installation Guide
52
coverage.
penetration.
Module Installation Locations, on page
Antenna Selection and Installation
45. This is applicable