Client Band Steering; Radio Interfaces And Understanding Client Associations - Ap 3600 - Cisco Aironet 1700 Deployment Manual

Client Band Steering

In order to optimize client performance, 802.11ac clients are able to take advantage of ECBF (Explicit Compressed
Beam-Forming)–a IEEE 802.11ac standardized method of Beam-forming–similar in some ways to Cisco's ClientLink but
slightly different because the .11ac client needs to send "sounding information" to the AP and then the AP uses that sounding
information (from the client) to best send the signal back to the client using beam-forming.
ECBF only works with 802.11ac clients, Cisco ClientLink continues to be used with non-802.11ac
Note
clients to improve the overall performance of 802.11n and legacy clients resulting in an improved
performance with all clients rather than just 802.11ac clients. This helps maintain solid connections to
the AP without having to bounce clients off of the AP using other methods such as signal strength
causing needless roaming with the client who is not actually engaged in passing traffic.
It is a significant advantage to allow the module to service the 802.11ac clients while the integrated radio services the
non-802.11ac clients. Should the 802.11ac client require something the module radio does not support, (for example, Cisco
Client Extensions "CCX elements") the 802.11ac module will push the client to the integrated radio to service that request.

Radio Interfaces and Understanding Client Associations - AP 3600

As previously mentioned; the AP with module has three radio interfaces, "slots 0-2", and shares the same RF power
characteristics and SSIDs. This permits both radios to function as a "virtual" or "blended" radio, therefore; RRM controls both
the integrated radio and the module radio.
Given there is no "greenfield" 802.11ac mode, RRM, Rogue AP detection, and SI (Spectrum Intelligence) all continue to
function normally.
Figure 75 Understanding RF Radio Interfaces
Because 802.11ac is fairly new, having a dedicated module handling the VHT (Very High Throughput) requests makes it easy
to see which clients are connected at 802.11ac rates and which 802.11ac clients are actually connecting at 802.11n rates. This
is accomplished by observing the SLOT ID.
Cisco Aironet Series 1700/2700/3700 Access Point Deployment Guide
Cisco Aironet Series 3700 Access Point