When designing the AP 2800 and AP 3800 Cisco wanted to bring the very best technology into the
device. A trade-off was made to support dual 5
–
GHz 160 MHz rather than the extra spatial stream, as
the additional spatial stream provides little real benefit.
In order to maintain a good 4-SS link, one needs n+1 antennas (meaning you cannot beam-form a 4-ss
client when the maximum number of antennas is 4. Additionally, there are few, if any, 4-SS clients
because the battery requirements of such a client are prohibited or limited to devices such as PCI card
or other "plugged in devices".
So while it may seem like MU-MIMO 4 spatial streams is an advantage, MU-MIMO 4 Spatial streams
seems like an advantage, MU-MIMO operation is for the most part limited to three 1-SS users or 1-SS
and one 2-SS user. The benefit is only there when you have a single 4-SS client, which is a very small
benefit.
Cisco has for years developed products using 3-SS as we use our 4
th
antenna to beam-form using
ClientLink to maintain a robust 3-SS signal over a greater distance than what could be reasonably
maintained without transmit beam-forming (TxBF).
Cost sensitive customers who don't require advanced features such as Cisco ClientLink, CleanAir, 160
MHz operation, FRA, mGig can certainly use the AP 1850 and gain 4-SS, but it will not outperform the
AP 2800 and AP 3800.
8
How Does AUTO-Link Aggregation (LAG) work with the AP 2800 and AP 3800?
Both the 2800 and 3800 support LAG across their primary ethernet interfaces and AUX ports. This would
provide 2Gbps of uplink to the access point. When operating in LAG, the 3800's multigigabit port will
operate as a single GE port.
The following Cisco switching series support LAG with the APs:
•
Catalyst 3850 / all models (non
–
Converged Access mode)
•
Catalyst 3650 / all models (non
–
Converged Access mode)
•
Catalyst 4500/Sup
‐
8E
•
Catalyst 6500/Sup 720 or newer
9
What is ClientLink 4.0? How is it different from IEEE 802.11ac Wave-2 beam
–
forming?
ClientLink 4.0 is a beamforming capability built into Cisco Aironet
®
wireless LAN access points. When
the access point (AP) concentrates signals toward the receiving client, that client is better able to "hear"
the AP's transmission, so throughput is greater. ClientLink also enhances performance in the uplink
(client-to-AP) direction, so that the AP can also better hear the client communications. The result improves
performance in both directions.
By comparison, many competing 802.11ac-capable APs offer uplink-only enhancements, from client to
access point. Many 802.11ac-capable AP suppliers also base their downlink enhancements on the optional
transmit beamforming (TxBF) feature in 802.11ac, which requires TxCBF support in the client device
to operate.
Cisco ClientLink technology is unique in offering both uplink and downlink performance improvements,
and it does not require any special capabilities in the client device to work.
ClientLink works with all client technologies. It makes sure each client type always operates at the best
possible rate, as determined by the 802.11 access technology supported, network conditions, and the
distance of the client from the Wi-Fi AP. ClientLink helps to maintain maximum client rates.
Cisco Aironet Series 2800/3800 Access Point Deployment Guide
61
Frequently Asked Questions (FAQ's)
Содержание aironet 2800 series
Страница 6: ...Cisco Aironet Series 2800 3800 Access Point Deployment Guide 2 Overview ...
Страница 50: ...Cisco Aironet Series 2800 3800 Access Point Deployment Guide 46 AP 2800 and AP 3800 Powering Options ...
Страница 54: ...Cisco Aironet Series 2800 3800 Access Point Deployment Guide 50 AP 3800 and Multigigabit Ethernet mGig ...
Страница 62: ...Cisco Aironet Series 2800 3800 Access Point Deployment Guide 58 Related References Previous Deployment Guides ...
