Dual Radio Operation" Section; External Antennas" Section - Cisco Aironet 1520 Series Hardware Installation Manual

Chapter 1 Overview
R E V I E W D R A F T — C I S C O C O N F I D E N T I A L
Dual Radio Operation
The access point supports 2.4-GHz and 5-GHz radios using external antennas (see
The LAP1522 model supports simultaneous dual-radio operation using a 2.4-GHz 802.11b/g radio and
a 5-GHz 802.11a radio.The 5-GHz radio can operate in either the upper industrial, scientific and medical
(ISM) 5.8-GHz band or the public safety 4.9-GHz band. The 5-GHz radio supports one antenna and is
used for backhaul operations to the controller.
The 4.9-GHz band requires a license and can only be used by qualified public safety operators as defined
Note
in section 90.20 of the FCC rules.
The 2.4-GHz radio supports two or three antennas for multi-input, single output (MISO) operation. The
access point uses two or three receivers to support maximum ratio combining (MRC) to enhance receiver
performance. MRC is a technique that combines the signals from multiple receivers in a manner to
optimize the signals. MRC can provide up to 3 dB of increased receive signal strength with two receive
antennas or up to 5 dB with three antennas.
External Antennas
The access point supports up to three N-type radio frequency (RF) antenna connectors on the top of the
unit and two on the bottom of the unit. The number of active antenna connectors depends upon the access
point configuration (see
supports multiple 2.4-GHz antennas for MISO operation, but only one 5-GHz antenna.
When using the optional Cisco compact omnidirectional antennas, the 2.4- and 5-GHz antennas connect
directly to the access point. The Cisco omnidirectional antennas use vertical polarization.
Only trained and qualified personnel should be allowed to install, replace, or service this equipment.
Warning
Statement 1030
The access point has been designed to operate with the antennas listed below and with a maximum gain
of 8 dBi for 2.4 GHz and 17 dBi for 5 GHz. Antennas not in this list or with a higher gain are strictly
prohibited for use with the access point. The required antenna impedance is 50 ohms.
To reduce potential radio interference to other users, the antenna type and its gain should be chosen so
that the equivalent isotropically radiated power (E.I.R.P.) is not more than required for successful
communication.
For directly mounted antennas, you must not add weatherproofing around the antenna connectors
Caution
because the antenna drain holes might be blocked and damage the antenna.
OL-12632-03
Antenna Connector Locations, page
Cisco Aironet 1520 Series Outdoor Mesh Access Point Hardware Installation Guide
Hardware Features
"External
1-5). All access point configurations
Antennas").
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