10/10/03
Airespace AP External and Internal Antennas
90-100584-004
Airespace Product Guide
45
About Airespace AP External and Internal Antennas
Airespace AP External and Internal Antennas
Note:
Airespace APs must use the factory-supplied internal or external antennas to avoid
violating FCC requirements and voiding the user’s authority to operate the equipment. Refer
to
FCC Statements for Airespace APs
for detailed information.
The 1200 Airespace AP enclosure contains one 802.11a and/or one 802.11b/g radio and four (two
802.11a and two 802.11b/g) high-gain antennas, which can be independently enabled or disabled to
produce a 360-degree omnidirectional coverage area.
Also note that the wireless LAN operator can disable either one of each pair of the Airespace AP internal
antennas to produce a 180-degree sectorized coverage area. This feature can be useful, for instance,
for outside-wall mounting locations where coverage is only desired inside the building.
The following sections contain more information about Airespace AP internal and external antennas:
•
•
•
802.11a Internal Antenna Patterns
•
802.11b/g Internal Antenna Patterns
•
802.11a/b/g Internal Antenna Patterns
External Antenna Connectors
External Antenna Connectors
The AS-1200-A, AS-1200-BG, and AS-1200-ABG Airespace APs have male reverse-polarity TNC jacks
for installations requiring factory-supplied external directional or high-gain antennas. The external
antenna option can create more flexibility in Airespace AP and antenna placement.
Note that the 802.11b/g 2.4 GHz Left external antenna connector is associated with the internal Side A
antenna, and that the 2.4 GHz Right external antenna connector is associated with the internal Side B
antenna. When you have 802.11b/g diversity enabled, the Left external or Side A internal antennas are
diverse from the Right external or Side B internal antennas.
Also note that the 802.11a 5 GHz Left external antenna connector is separate from the internal
antennas, and adds diversity to the 802.11a transmit and receive path.
Finally, note that the AS-1200-A-int, AS-1200-BG-int, and AS-1200-ABG-int Airespace APs are not
equipped with external antenna jacks, and are used for installations requiring only internal Airespace
AP antennas.
Antenna Sectorization
Antenna Sectorization
Note that the Airespace System supports Antenna Sectorization, which can be used to increase the
number of clients and/or client throughput in a given air space. Installers can mount two Airespace APs
back-to-back and the Airespace System operator can disable the second antenna in both Airespace APs
to create a 360-degree coverage area with two sectors.
802.11a Internal Antenna Patterns
802.11a Internal Antenna Patterns
The 1200 Airespace AP can contain one 802.11a radio which drives two fully-enclosed high-gain
antennas which can provide a large 360-degree coverage area. The two internal antennas can be used
at the same time to provide a 360-degree (Omnidirectional) coverage area, or either antenna can be
disabled to provide a 180-degree (Sectorized) coverage area.
When equipped with an optional factory-supplied external antenna, the 802.11a radio supports receive
and transmit diversity between the internal antenna and the external antenna. The diversity function
provided by Airespace radios can result in lower multipath fading, fewer packet retransmissions, and
higher client throughput.
