AP 2800 and AP 3800
Powering Options
With each advance in
wireless technology, access points are increasing in the number of radios,
processing power and memory. In 2001 the AP-350 Access Point had one 2.4 GHz
radio and processor requiring only 6 Watts of power. These early PoE access
points would fully function using the earlier 802.3af (15.4W) powering systems
developed in 2000-2003.
Figure 1. Early AP-350
used 6 Watts-Newer AP 3800 requires 802.3at or PoE+
Later PoE standards
have since emerged with 802.3at providing up to 30 Watts at the Power Sourcing
Equipment (PSE). Many of Cisco's previous access points such as the AP-1850 and
AP-3700 worked best with the higher power sources 802.3at and PoE+ but would
function with "reduced functionality" if powered by the older 802.3af 15.4W
powering systems.
With the introduction
of the XOR radio along with more advanced features, it simply is not feasible
to run these higher performance access points on the older legacy 802.3af
(15.4W) powering systems. Customers who have such older systems should upgrade
to 802.3at (30W) PoE equipment or systems that support uPoE for best
performance or use a different power source such as a mid-span injector or
local power supply. Note: If the AP2800 and AP 3800 are powered from an 802.3af
power source the LED will cycle though the colors and the radios will be
disabled.
Performance requires
power as the AP 2800 and AP 3800 have much more advanced features such as:
-
Dedicated
microprocessor and memory for each radio band
-
Dual core
processor to manage access point and Ethernet functionality
-
Additional XOR
radio and antenna switching circuitry, pushing transceiver count to 12 radios
-
Cisco CleanAir
silicon for complete spectrum analysis and interference detection
-
Cisco ClientLink
powerful (legacy .11a/g/n and .11ac Wave 1 beamforming)–improving older client
connectivity and performance; IEEE specification is limited to only TxBF on
802.11ac Wave-2 clients
-
Additional
(auxiliary) Ethernet port, USB and advanced radio functions such as 160 MHz /
Dual XOR
-
Support for smart
antenna functionality (WSM monitor mode and enhanced location)
-
802.3bz (NBASE-T)
mGig Ethernet support (AP 3800)
-
Future hardware
expandability using modular technology (AP 3800)
Understanding
different types of PoE powering standards:
-
Cisco
Pre-standard PoE - Original implementation 6-7 Watts (2000-2001)*
-
Cisco
Pre-standard PoE - upgraded to negotiate up to 10-15 Watts via CDP (2001-2003)
-
IEEE 802.3af PoE
mechanism that supplies power up to 15.4W (July 2003)*
-
IEEE 802.3at PoE
mechanism that supplies up to 30W (2009)*
-
UPoE Cisco method
of Universal Power over Ethernet that supplies power up to 60W (2014)*
Note |
The * indicates
these are approximate dates and PoE is defined as the maximum power required at
the source.
|
Cisco AP 2800 and AP
3800 easily function with 802.3at powering systems and for advanced features
like module support (AP 3800) Cisco UPoE can be used.
Figure 2. AP 2800 and AP
3800 requires an 802.3at or better PoE source
If an 802.3at or
better power source is not available, the following Cisco mid-span injectors
may be used.
Figure 3. Low cost
802.3at GbE injector for AP 2800 and AP 3800 (if mGig is not
required)
An additional
mid-span injector capable of 802.3bz (known as mGig / N-BASE-T).
Figure 4. Planned
Mid-Span Injector
Note |
The Cisco AP 2800
does not support a local power supply; however the AP 3800 does have a new high
wattage supply that can be used in applications where a PoE source is
unavailable.
|
Figure 5. White power
supply and cord
Figure 6. AIR-PWR-50
mechanicals - Spare part # AIR-PWR-50=
Note |
The following
Mid-Span devices are not compatible with the AP 2800 AP 3800:
-
Mid-Span
Injectors–AIR-PWRINJ, AIR-PWRINJ2, AIR-PWRINJ3, AIR-PWRINJ4 and AIR-PWRINJ5
-
Local power
supplies–AIR-PWR-A, AIR-PWR-B and AIR-PWR-C
|