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Cisco Aironet Series 1700/2700/3700 Access Point Deployment Guide
Cisco Aironet Series 3700 Access Point
Figure 78
A Peek Inside the AP 3700 Showing Conductive Gasket and Dual-Band Antenna Design
Power Over Ethernet and the AP 3700
The AP 3700 with integrated 802.11ac wave-1 radio is designed to run from Power over Ethernet (PoE) sources, local power,
or via mid-span or power injector. If the AP 3700 is powered by PoE and the source is 802.3af (15.4 Watts) the AP will come
up and fully function in a 3x3:3 mode, for enhanced performance additional power sources such as 802.3at, enhanced PoE,
Cisco PoE Injector-4, or local power may be used. With additional power (greater than 15.4W) supplied, the 3700 will shift
into the 4x4:3 mode.
Tip
Modes such as 4x4:3 implies 4 receivers and 4 transmitters capable of 3 spatial streams.
This enhances performance by allowing the AP to beamform to 3-ss clients (Clientlink 3.0). It also guarantees an “extra”
receiver to help decode weak client signals for better uplink as well as downlink performance.
Cisco understands the need that some customers have to stay in the .3af (15.4 power budget). If the customer has lower PoE
requirements and still wishes to use the AP 3700 and say the WSSI module, the AP 3700 will still function with the module
but in a 2x2:2 mode with the module enabled.
Also, smaller controllers, for example the Cisco 2500 series controller, support the lower 15.4W PoE specification native and
given that it is a smaller controller it should be fine. However, it is suggested that higher sources of power (either locally or
PoE)) should be used when the highest throughput is required.
Note
A Cisco PWR-INJ4 PoE injector could also be used, but avoid the PWR-INJ5 because it has only 15.4 W.
In order to determine if the AP 3700 is running at high PoE power or reduced (15.4W) power, one can check the controller and
easily determine this.