Aerohive HiveAP 20, Руководство по развертыванию

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Deployment Guide 55
H
IVE
AP 340 P
RODUCT
O
VERVIEW
Using MIMO with Legacy Clients
In addition to supporting up to 300-Mbps throughput per radio for 802.11n clients, MIMO (Multiple In, Multiple Out)
can improve the reliability and speed of legacy 802.11a/b/g client traffic. When an 802.11a/b/g access point does
not receive acknowledgement that a frame it sent was received, it resends that frame, possibly at a somewhat
lower transmission rate. If the access point must continue resending frames, it will continue lowering its
transmission rate. As a result, clients that could get 54-Mbps throughput in an interference-free environment might
have to drop to 48- or 36-Mbps speeds due to multipath interface. However, because MIMO technology makes better
use of multipath, an access point using MIMO can continue transmitting at 54 Mbps, or at least at a better rate than
it would in a pure 802.11a/b/g environment, thus improving the reliability and speed of 802.11a/b/g client traffic.
Although 802.11a/b/g client traffic can benefit somewhat from an 802.11n access point using MIMO, supporting such
legacy clients along with 802.11n clients can have a negative impact on 802.11n client traffic. Legacy clients take
longer to send the same amount of data as 802.11n clients. Consequently, legacy clients consume more airtime than
802.11n clients do, causing greater congestion in the WLAN and reducing 802.11n performance.
By default, the HiveAP 340 supports 802.11a/b/g clients. You can restrict access only to clients using the IEEE
802.11n standard. By only allowing traffic from clients using 802.11n, you can increase the overall bandwidth
capacity of the access point so that there will not be an impact on 802.11n clients during times of network
congestion. To do that, enter the following command:
radio profile <string> 11n-clients-only
You can also deny access just to clients using the IEEE 802.11b standard, which has the slowest data rates of the
three legacy standards, while continuing to support 802.11a and 802.11g clients. To do that, enter the following
command:
no radio profile <string> allow-11b-clients
By blocking access to 802.11b clients, their slower data rates cannot clog the WLAN when the amount of wireless
traffic increases.