User's Manual

435 | Adaptive Radio Management (ARM) Dell Networking W-Series ArubaOS 6.4.x| User Guide
the client has a good RSSIfrom the 5 Ghz radio, the controller will attempt to steer the client to the 5 Ghz
radio, as long as the 5 Ghz RSSI is not significantly worse than the 2.4 GHz RSSI, and the APretains a
suitable distribution of clients on each of its radios.
The client match feature is enabled through the AP's ARM profile. Although default client match settings are
recommended for most users, advanced client match settings can be configured using rf arm-profile commands in
the command-line interface.
ARM Coverage and Interference Metrics
ARM computes coverage and interference metrics for each valid channel, and chooses the best performing
channel and transmit power settings for each AP’s RF environment. Each AP gathers other metrics on their
ARM-assigned channel to provide a snapshot of the current RF health state.
The following two metrics help the AP decide which channel and transmit power setting is best.
l Coverage Index: The AP uses this metric to measure RF coverage. The coverage index is calculated as x/y,
where “x” is the AP’s weighted calculation of the Signal-to-Noise Ratio (SNR) on all valid APs on a specified
802.11 channel, and “y” is the weighted calculation of the Dell AP's SNR the neighboring APs see on that
channel.
To view these values for an AP in your current WLAN environment, issue the CLI command show ap arm
rf-summary ap-name <ap-name>, where <ap-name> is the name of an AP for which you want to view
information.
l Interference Index: The AP uses this metric to measure co-channel and adjacent channel interference. The
Interference Index is calculated as a/b//c/d, where:
l Metric value “a” is the channel interference the AP sees on its selected channel.
l Metric value “b” is the interference the AP sees on the adjacent channel.
l Metric value “c” is the channel interference the AP’s neighbors see on the selected channel.
l Metric value “d” is the interference the AP’s neighbors see on the adjacent channel.
To manually calculate the total Interference Index for a channel, issue the CLI command show ap arm rf-
summary ap-name <ap-name>, then add the values a+b+c+d.
Each AP also gathers the following additional metrics, which can provide a snapshot of the current RF health
state. View these values for each AP using the CLI command show ap arm rf-summary ip-addr <ap ip
address>.
l Amount of Retry frames (measured in %)
l Amount of Low-speed frames (measured in %)
l Amount of Non-unicast frames (measured in %)
l Amount of Fragmented frames (measured in %)
l Amount of Bandwidth seen on the channel (measured in kbps)
l Amount of PHY errors seen on the channel (measured in %)
l Amount of MAC errors seen on the channel (measured in %)
l Noise floor value for the specified AP
Configuring ARM Profiles
ARM profile settings are divided into two categories: Basic and Advanced. The Basic ARM settings include
ARM scanning checkbox and general configuration parameters such as channel and power assignments and
minimum and maximum allowed EIRP values. Most network environments do not require any changes to the