FortiWLC – Automatic Radio Resource Provisioning (ARRP)

Automatic Radio Resource Provisioning (ARRP)

By using the ARRP feature, each AP scans all channels and provides the scan details to the controller. The controller uses this information to select and allocate the best available channel per radio. By default, this feature is disabled.

  • Supported only on 11ac APs.
  • Once enabled, the virtual cell is not available for 11ac APs.
  • Non-11ac APs will continue to work as configured and will not be affected by auto channel feature.
  • The APs will reboot to the newly allocated channel after both initial planning and dynamic channel change.
  • If the ARRP is disabled, all 11ac APs will reboot to default channels.

Automatic Radio Resource Provisioning (ARRP)

Configuring Using WebUI

To enable this feature, go to Configuration > Wireless > ARRP and in the configuration tab, enable the Auto Channel option.

  • Planning Channel: Once enabled, the respective radios of all APs are set to the channels selected for radio 1 and radio 2. In the above screenshot, the planning channel is set to 1 / 20MHz for radio 1 and 149/40MHz for radio 2. Based on the report received by all APs, the controller allocates the optimum channel. DFS channels are not available to be set as planning channel.
  • Auto Power: The auto power functionality is applied only after channel allocation irrespective of when the auto power option was enabled. When enabled, the controller will determine the optimum power level between neighbouring (by channel) 11ac APs. The auto power option can be enabled and applied only when ARRP feature is enabled.
  • Freeze: The option is applied after the initial planning phase. When this option is disabled, the 11ac APs perform a periodic scan (at the end of every minute) on their allocated channels. This is used to determine the quality of the channel. If the quality of the channel crosses the threshold limit (based on three consecutive scans), it sends a request for change of channel. If enabled, the periodic scan is disabled and the 11ac APs remain in allocated channels irrespective of the channel quality.
  • If this option is disabled, the radio interface settings cannot be modified.
  • Timer State and Timer: This option is available only when the Freeze option is disabled. If Timer State is Off, channel scanning occurs every one minute continuously. To avoid frequent channel change, you can set the channel scan interval to happen at the end of 15

Automatic Radio Resource Provisioning (ARRP)

minutes. With this, channel scan is scheduled for once in 15 mins. In each scan cycle sampling is done for 10 iterations i.e. for 10 mins.

  • DFS: By default scanning and allocation of DFS channel is disabled during the planning phase. If enabled, the APs can scan DFS channels and they can be allocated DFS channels.
  • DFS option must be selected when the ARRP is enabled. Enabling DFS after enabling Auto RF will require re-planning of channel allocation for all APs
  • REPLAN: This option is to be used if a new AP is added to the network after the initial planning is complete.

The AP-Radio Interfaces tab lists all APs with its operating frequency and transmit-power respectively.

Configuring Using CLI
  • Use the show arrp‐config command to view the current settings

MC‐4200‐AC‐MCA(15)# show arrp‐config MCA Global Settings

Enable/Disable Auto Channel : enable Radio 1 Channel             : 11 Radio 1 Channel Width       : 20‐mhz Radio 2 Channel             : 48 Radio 2 Channel Width       : 20‐mhz

Auto Power on/off           : off

Freeze yes/no               : No

Timer State on/off          : on

Timer                       : 15

Dfs on/off                  : on

  • Use the show arrp‐ap‐radio‐interface command to view the list of APs and their operating frequency and power values.

MC‐4200‐AC‐ARRP(15)# show arrp‐ap‐radio‐interface

AP ID AP Name Radio1 oper ch Radio2 oper ch Radio1 Transmit Power (dBm) Radio2 Transmit Power (dBm)

  • AP‐3 6              36             24                            23

Automatic Radio Resource Provisioning (ARRP)

  • AP‐4 1              36             24                            23 6     AP‐6     6              40             24                            23 13    AP‐13    1              36             24                            23 17    AP‐17    1              36             24                            23 19    AP‐19    6              36             10                            13 20    AP‐20    6              36             24                            23

ARRP radio interfaces(7 entries)

  • Use the arrp global command followed by one of the following options to configure and use the ARRP feature

‐auto‐power ‐ To enable or disable auto allocation of transmit power

‐dfs ‐ To enable or disable the use of DFS channels in planning

‐disable ‐ To disable ARRP   

‐Enable ‐ To enable ARRP

‐Freeze‐ To enable or disable dynamic channel scanning

‐radio1‐channel‐planning‐ To specify channel for initial planning

‐radio2‐channel‐planning‐ To specify channel for initial planning

‐replan‐ To perform re‐planning if a new AP has joined network

‐timer‐state‐ Enable or disable to avoid frequent channel change

‐timer‐value‐ To specify the time interval for the dynamic channel scan

  • If disabled, existing vCell profiles will be pushed to all 11ac APs irrespective of whether the AP was part of the vCell profile before auto channel feature was enabled. Native cell profiles will remain unchanged.
  • As part of auto power functionality, the Tx power levels on the AP is not increased back to default values if the neighboring AP which this AP earlier reported as having high power goes down.

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