Allied Telesis AT-WA7501 - Manual (Page 62)

Chapter 2: Installing the Access Points
62
Stacked Antenna Positioning for Dual Radio Access Points
As an alternative to the physical separation of omni antennas, you can
mount them along a single axis to minimize the antenna-to-antenna
coupling.
Differences in Antenna Diversity Among 802.11b and 802.11a Radios
Antenna diversity works differently for 802.11b radios than for the 802.11a
radio. Currently, the 802.11g radio with software release 2.2 does not
support antenna diversity.
Antenna Diversity for 802.11b
Antenna diversity lets you attach two antennas to one radio to increase the
odds of receiving a better signal on either of the antennas. The 802.11b
radio features antenna diversity. If you are using antenna diversity,
placement of the antennas is critical because each antenna has a
particular function. Antennas placed too close together may cause
interference with each other. Antennas placed too far apart may not be
able to establish two-way communications with other radios.
Access Point
Primary antenna
for Radio 1
All four antennas
are mounted along
a single axis.
Secondary antenna
for Radio 1
Secondary antenna
for Radio 2
Primary antenna
for Radio 2