Unlike the integrated
antenna models, the external antenna model units have four primary RP-TNC
connectors on top of the device and an additional four RF connectors as well as
digital via a new smart antenna connector.
Figure 8. Smart antenna
connector is an integrated feature of the "E/P" series products
When the smart
antenna connector is not used, the AP 2800 and AP 3800 "E/P" series function
much like an AP 3700 where both the 2.4–GHz FRA radio and the integrated 5–GHz
radio share the top RP-TNC connectors in a dual band mode.
This is sometimes
referred to as Dual Radiating Element (DRE) or dual band mode.
However, once the
smart antenna connector is inserted, the access point senses the presence of
the new connector/antenna and automatically switches the FRA (XOR radio) from
the top connector that was previously in 2.4 GHz/5 GHz DRE mode to the smart
connector port. This allows the top connectors for the 5 GHz radio serving
clients and the FRA radio is now free (regardless of mode) to use the smart
connector for RF communications.
The flexibility to do
this allows many different types of modes, from discrete single band operation
(SRE) to DRE operation. The ability to change the antenna controls (sending
different bands 2.4 GHz and 5 GHz out of different ports in SRE and/or DRE
mode) is sometimes referred to as Cisco "Flexport" and was first introduced in
the AP-1530 series.
Figure 9. Antenna control
(default) and with smart antenna connector installed
The role of the XOR
radio is selected in software, and the modes are Band, Client Serving or
Monitor mode. This can be set manually or automatically if RRM control is
Figure 10. FRA (XOR) radio
defaults to 2.4 GHz Client serving but is selectable in software
If you change the
band from 2.4 GHz to 5 GHz then you must have 100–MHz separation.
Figure 11. Error when
channels are set too close
If the antenna has a
smart antenna connector it allows the AP to sense what type of antenna is
installed and configure the AP accordingly.
Using the smart
antenna connector to RP-TNC adapter AIR-CAB002-DART-R the FRA (XOR) radio can
now be used in many applications as the RF system on the FRA (XOR) radio will
now use the four external RP-TNC connectors for a wide variety of application
Figure 12. Cisco Smart
Antenna Adapter AIR-CAB002-DART-R
The smart RF antenna
connector sometimes referred to as a DART carries the digital signals (18 mins)
as well as the four analog RF ports from the XOR radio.
The term DART is an
Amphenol trademark name for this type of connector.
Unlike the internal
models, the smart connector allows both antenna systems to be located away from
each other enabling deployments that cannot be done with the internal model.
For example, the creation of two 5–GHz Macro cells is now possible in addition
to separating the 5–GHz cells into different areas (think inside/outside) or
different coverage areas in a factory or stadium.
customer requirements dictate that 2.4–GHz RF operation be on one set of
antennas and 5 GHz on a completely different set of antennas, and that is also
Figure 13. Smart antenna
cable adapter and the Cisco external Omni antenna
Since both sets of
antennae can be physically spaced apart, many new RF design opportunities
become available allowing for many different types of new and unique
directional deployments (think hospital room and a long hallway) with one AP
Any combination of
Micro and Macro cell deployments
antennas, two different 5–GHz coverage cells can be done with 1 AP
(factory and warehouse deployments) can use back to back 6 dBi Patch antennas
AP using 2x 5–GHz
radio can double the coverage with the addition of one antenna
and other locations can double capacity on existing Ethernet cable plan
One access point
can support both indoor and outdoor deployments
Access point can
serve 5–GHz clients while performing full 2.4 & 5–GHz wireless monitor
When using the smart
antenna connector and dual 5–GHz mode the caveats are:
Figure 14. Example using
"E/P" version to create two macro cells can be supported
Channels must not
be closer than 100–MHz
not be mounted so that energy from one antenna is directed into another
Ideally if one
antenna is Omni then 6 ft or 2 meter physical separation
Antennas may be
closer if used in Micro cell (very low power) is used
Any combination of
Micro/Macro can be used as long as physical isolation exists
SSIDs must be the
same (this may change in later releases)