Dynamic Radio Management (DRM)

Auto Channel Selection (ACS)

ACS provides an easy way to optimize channel arrangement based on the current situation in the field. ACS provides an optimal solution only if it is triggered on all APs in a deployment. Triggering ACS on a single AP or on a subset of APs provides a useful but suboptimal solution. Also, ACS only relies on the information observed at the time it is triggered. Once an AP has selected a channel, it remains operating on that channel until the user changes the channel or triggers ACS.

ACS can be triggered by one of the following events:

• A new AP registers with the controller and the AP Default Settings channel is Auto.
• A user selects Auto from the Request New Channel drop-down list on the Wireless AP‘s radio configuration tabs.
• A user selects Auto from the Channel drop-down list on the AP Multi-edit screen.
• If Dynamic Channel Selection (DCS) is enabled in active mode and a DCS threshold is exceeded.
• A Wireless AP detects radar on its current operating channel and it employs ACS to select a new channel.
• You can initiate ACS from the Channel Inspector Report. For more information, see Channel Inspector Report.
• ACS is supported for Sites in Cloud deployments. The ACS command is sent to the master AP and distributed. Each Site is considered an RF domain.
• Channel Plan — If ACS is enabled, you can define a channel plan for the AP. Defining a channel plan allows you to limit which channels are available for use during an ACS scan. For example, you may want to avoid using specific channels because of low power, regulatory domain, or radar interference. Select from the following options:

  Depending on the radio used, when defining a channel plan you can either create your customized channel plan by selecting individual channels or you can select a default 3 or 4 channel plan.

  You can use the channel plan to avoid transmission overlap on 40 MHz channels of the wireless 802.11n APs. To avoid channel overlap between wireless 802.11n APs that operate on 40 MHz channels, configure the channel plan for the 5 GHz radio band to use every other channel available.

  If using half of the available channels is not an option for your environment, do not configure a channel plan. Instead, allow ACS to select from all available channels. This alternate solution may contribute to increased congestion on the extension channels.

  

  Note

  ACS in the 2.4 GHz radio band with 40 MHz channels is not recommended due to severe co-channel interference.

Dynamic Channel Selection (DCS)

DCS allows a Wireless AP to monitor traffic and noise levels on the channel on which the AP is currently operating. DCS can operate in two modes:

• Monitor — When DCS is enabled in monitor mode and traffic or noise levels exceed the configured DCS thresholds, an alarm is triggered and an information log is generated. The DCS monitor alarm is used for evaluating the RF environment of your deployed APs.
• Active — When DCS is enabled in active mode and traffic or noise levels exceed the configured DCS thresholds, an alarm is triggered and an information log is generated. In addition, the AP ceases operating on the current channel and ACS is employed to select an alternate channel for the AP to operate on. DCS does not trigger channel changes on neighboring APs.
  

  Note

  If DCS is enabled, DCS statistics can be viewed in the Wireless Statistics by Wireless APs display. For more information, see Working with Reports and Statistics.

Auto Tx Power Control (ATPC)

ATPC guarantees your LAN a stable RF environment by automatically adapting transmission power signals according to the coverage provided by the APs. ATPC can be either enabled or disabled.

When you disable ATPC, you are given the option of automatically adjusting the Max Tx Power setting to match the Current Tx Power Level. In the case of AP Multi-edit, if you reply yes, then each individual AP's Max Tx Power setting is adjusted to correspond with its Current Tx Power Level in the database.