Support Support Downloads Knowledge Base Juniper Support Portal Community

Knowledge Base

Search our Knowledge Base sites to find answers to your questions.

Ask All Knowledge Base Sites All Knowledge Base Sites JunosE Defect (KA)Knowledge BaseSecurity AdvisoriesTechnical BulletinsTechnotes Sign in to display secure content and recently viewed articles

[WLA] What does the AP do when its radio is enabled in a regulatory domain requiring DFS?



Article ID: KB25042 KB Last Updated: 17 Jul 2012Version: 1.0

This article describes the behavior that radio 2 (5GHz) of an AP has when it is enabled and configured to use a channel from the UNII-2, UNII-3 and UNII-3extended.



When an 11a radio is enabled in a regulatory domain that requires DFS, it does not transmit anything for 60 seconds. This is called the initial channel check.

A. If no radar is detected during the initial channel check, then the radio's transmitter is enabled at the end of 60 seconds.

B. If the radar is detected during the 60 second initial channel check, it does the following:
  1. The AP sends a syslog to the wireless controller indicating that radar has been detected.

  2. The AP reports a 'radar detected' status to the wireless controller for this AP.

  3. The AP sends a notification to clients that it has detected radar on the current channel.

  4. The AP ceases/does not start transmitting on the current channel.

  5. The AP starts a 30 minute timer, called the quiet period timer.

  6. The AP continues monitoring the current channel for radar.
Comment on this article > Affected Products Browse the Knowledge Base for more articles related to these product categories. Select a category to begin.

Getting Up and Running with Junos

Getting Up and Running with Junos Security Alerts and Vulnerabilities Product Alerts and Software Release Notices Problem Report (PR) Search Tool EOL Notices and Bulletins JTAC User Guide Customer Care User Guide Pathfinder SRX High Availability Configurator SRX VPN Configurator Training Courses and Videos End User Licence Agreement Global Search