Cisco Catalyst 9800 Series Wireless Controller Software Configuration Guide, Cisco IOS XE 26.x

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Cisco Catalyst 9800 Series Wireless Controller Software Configuration Guide, Cisco IOS XE 26.x

Cisco CleanAir

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Introduces Cisco CleanAir technology, describing key terminology, system components, and comparisons with Wi-Fi chip-based RF management. Explains persistent device handling, spontaneous interference, device merging, EDRRM and AQR update modes, high availability, and important operational considerations.


A Cisco CleanAir system is a wireless spectrum management solution that

  • identifies and monitors all users and interferers in the industrial, scientific, and medical (ISM) bands

  • provides real-time radio frequency (RF) visibility and actionable interference information, and

  • enables the network to automatically or manually respond to interference, improving wireless performance.

Table 1. Feature history for Cisco CleanAir

Release

Feature

Feature Information

Cisco IOS XE 17.13.1

EDRRM Support for 6 GHz Band Radio

The Event-Driven Radio Resource Management (EDRRM) is enabled in the 6 GHz band radio of AP.

Cisco CleanAir systems consist of CleanAir-enabled APs and a Cisco Catalyst 9800 Series Wireless Controller. The APs gather device information across the ISM bands, detect and evaluate interference sources, and forward this information to the controller. The controller manages the APs and displays detected interference devices.

For devices operating in the unlicensed band, Cisco CleanAir systems provide detailed information about device identity, interference impact, and recommended actions to mitigate issues. CleanAir simplifies RF management, allowing users to maintain optimal wireless performance without requiring deep RF expertise.

Components of Cisco CleanAir systems

Cisco CleanAir systems are comprised of several key hardware and software elements:

  • Cisco CleanAir-enabled APs: These devices actively scan the wireless spectrum for all active transmitters.

  • Wireless controllers: Cisco Catalyst 9800 Series Wireless Controller.

  • Management platforms: Provides centralized management and visualization of spectrum and interference data forwarded by the controllers.

How Cisco CleanAir systems detect and respond to interference

  1. Always-On spectrum awareness: Cisco CleanAir-enabled APs scan the industrial, scientific, and medical (ISM) bands, identifying and evaluating all radio devices that may cause interference.

  2. Unified control and interference intelligence: The controller controls the access points and displays the interference devices.

  3. Actionable insight for every interferer: For every device operating in the unlicensed band, Cisco CleanAir provides information about what it is, how it is impacting your wireless network, and what actions you or your network should take. It simplifies RF so that you do not have to be an RF expert.

Benefits of Cisco CleanAir systems

  • Simplifies spectrum management: Provides visibility into interference without requiring advanced RF expertise.

  • Improves network reliability: Automatically detects and resolves issues affecting Wi-Fi performance.

  • Supports advanced WLAN services: Ensures quality for voice over wireless and IEEE 802.11 operations by minimizing RF interference.

Detecting and mitigating interference

In a busy office environment, multiple devices such as microwave ovens, cordless phones, and Bluetooth devices operate in the 2.4-GHz and 5-GHz ISM bands. These can disrupt Wi-Fi communication. Cisco CleanAir systems detect these interferers, identify their impact, and automatically adjust wireless channels or prompt users to take corrective action.

A basic wireless LAN without CleanAir functionality cannot detect, identify, or respond to environmental interference in real time, meaning performance issues can go unnoticed and unresolved.

Cisco CleanAir systems function like air quality sensors in a smart building—they continuously monitor the environment, detect harmful agents, and trigger responses to ensure optimal conditions for all users.



Cisco CleanAir components

Summary

Cisco CleanAir technology uses a coordinated set of hardware and software components to detect, report, and address wireless interference. Each part of the system contributes to maintaining optimal air quality and reliable wireless performance.

The key components involved in the process are:

  • Cisco CleanAir-enabled AP: Collects information about Wi-Fi interference sources and processes it. The AP collects and sends the Air Quality Report (AQR) and Interference Device Report (IDR) to the controller .

  • Controller: Controls and configures CleanAir-capable access points, collects and processes spectrum data, provides user interfaces (GUI and CLI), and detects, merges, and mitigates interference devices. The controller also detects, merges, and mitigates interference devices using RRM TPC and DCA For details, see Interference Device Merging.

CleanAir technology ensures wireless networks remain reliable by automatically detecting sources of interference and providing tools for administrators to analyze and respond to RF threats.

Workflow

Figure 1. Cisco CleanAir Solution

These stages describe the operation of Cisco CleanAir components in the system.

  1. Configuration: Configures Cisco CleanAir capabilities on the APs.
  2. Detection: Cisco CleanAir-enabled APs continuously scan the wireless environment for interference sources and assess air quality.
  3. Reporting: APs generate reports such as Air Quality Reports (AQRs) and Interference Device Reports (IDRs), which summarize detected interference and air quality indexes.
  4. Aggregation: Wireless controllers collect AQRs and IDRs from all APs, process the data, and store it in relevant databases.
  5. Analysis and Response: Controllers use built-in mechanisms (like Radio Resource Management) to mitigate interference and maintain optimal RF conditions.
  6. Advanced Services: Cisco Spaces or CMX tracks interference devices over time and location, merges data from multiple controllers, and provides comprehensive threat detection with adaptive Wireless Intrusion Prevention System (WIPS).
  7. Specialized Troubleshooting (optional): For in-depth RF analysis, an administrator can connect a CleanAir-enabled AP directly to a PC running Cisco Spectrum Expert.

Result

The Cisco CleanAir system delivers end-to-end automated detection, analysis, and mitigation of wireless interference, enabling proactive network management and high-quality wireless performance.

Prerequisites for CleanAir

You can configure Cisco CleanAir only on CleanAir-enabled access points.

Only Cisco CleanAir-enabled access points in these access point modes can perform Cisco CleanAir spectrum monitoring:

  • Local : In this mode, each Cisco CleanAir-enabled access point radio provides air quality and interference detection reports for the current operating channel only. An AP measures air quality and interference only when it is not transmitting Wi-Fi frames. When channel utilization is high, CleanAir detects less interference.

  • FlexConnect : When a FlexConnect access point is connected to the controller, its Cisco CleanAir functionality is identical to local mode.

  • Monitor : When Cisco CleanAir is enabled in monitor mode, the access point provides air quality and interference detection reports for all monitored channels.

    • All : All channels

    • DCA : Channel selection governed by the DCA list

    • Country : All channels are legal within a regulatory domain


Restrictions for CleanAir

Access points in monitor mode do not transmit Wi-Fi traffic or 802.11 packets. They are excluded from radio resource management (RRM) planning and are not included in the neighbor AP list. IDR clustering depends on the device ’s ability to detect neighboring in-network APs. Correlating interference device detections from multiple APs is limited between monitor-mode APs.

CleanAir is not supported where the channel width is 160 MHz.


Difference between Spectrum Intelligence and Cisco CleanAir

Feature

Spectrum Intelligence

Cisco CleanAir

Noise identification

Reports broad, often vague RF noise without pinpointing sources

Precisely identifies interference type, source, potential impact to a WLAN

Noise measurement method

Relies on long-term averaging, which smooths out important details and reduces resolution of measurements

Captures real-time events with full granularity

Response style

Primarily reacts after interference is noticed

Enables proactive, context-aware mitigation allowing for intelligent, proactive decisions.

Transient interference handling

Averaging measurements reduces resolution of measurements, and disruptive signals do not appear to need mitigation.

Flags brief, spontaneous interference events immediately

Cisco CleanAir access points can detect and report severity of the interference .

Spectrum event-driven RRM is one such mitigation strategy.

Note

Spectrum event-driven RRM can be triggered only by Cisco CleanAir-enabled access points in local mode.


Persistence interference

A persistent device avoidance is a wireless interference mitigation feature that

  • identifies and continuously tracks intermittent interference sources such as microwave ovens,

  • maintains channel avoidance for affected APs even if the interference is not constantly present, and

  • automatically updates Radio Resource Management (RRM) whenever the interfering device or related access points are moved.

For example, if a microwave oven operates in a break room only for a few minutes at a time, Cisco CleanAir identifies the microwave as an interference source, locates the affected portion of the band and APs most severely affected, and directs RRM to avoid those channels persistently. Even if the microwave is not active all day, the system maintains avoidance as long as the device is periodically detected. If you move either the microwave oven or the surrounding access points, the algorithm updates RRM automatically

Classes of persistent interference sources

Certain devices, once detected, are likely to remain in place and may cause ongoing interference. Cisco CleanAir can bias the affected channel in Radio Resource Management (RRM) so that CleanAir “remembers” the potential for interference. See Radio Resource Management White Paper.

These device classes qualify as persistent interference sources:

  • Microwave ovens

  • Outdoor Ethernet bridges

  • WiMax fixed and mobile devices

  • Motorola Canopy systems

Special case: Bluetooth devices

Bluetooth devices are detected and reported as interference only when actively transmitting. They often enter power-save modes, so interference may only be noticed during active streaming of data or voice.

Persistent devices detection

CleanAir-capable Monitor Mode AP collects information about persistent devices on all configured channels and store the information in controller . Local or Bridge mode AP detects interference devices on the serving channels only.


Persistent device avoidance

When a Persistent Device (PD) is detected in the CleanAir module, it is reported to the RRM module on the MA. This information is used in the channel selection by the subsequent EDRRM Event Driven RRM (ED-RRM) signal sent to the RRM module.


Spontaneous interference

Spontaneous interference is interference that appears suddenly on a network and may jam one or more channels. With Cisco CleanAir spectrum, event-driven RRM, you can set a threshold for air quality, abbreviated as AQ. If air quality drops below this threshold, the system immediately changes the affected AP’s channel. Although most RF management systems avoid interference, they require time for information to spread before channels update. Cisco CleanAir uses AQ measurements to continually check the spectrum and can switch channels within 30 seconds.

For example, if your AP detects interference from a device such as a video camera, it switches channels within 30 seconds after the interference begins. Cisco CleanAir also helps you identify and locate the interference source so you can take permanent steps to resolve the issue later.


EDRRM and AQR update mode

An EDRRM and AQR update mode is a wireless network feature set that
  • enables APs experiencing severe interference (“in distress”) to bypass normal RRM intervals and immediately change channels,

  • requires CleanAir technology for monitoring and reporting classified interference devices, and

  • provides fast action and remote configuration through control messages and local spectrum management.

  • EDRRM (Event Driven Radio Resource Management): A function that allows an AP to react instantly to excessive interference by changing channels immediately instead of waiting for scheduled RRM intervals.

  • AQR (Air Quality Reporting) update mode: A process by which CleanAir APs monitor air quality and report classified interference devices every 15 minutes; when interference causes substantial air quality degradation, EDRRM is triggered.

If a classified interference device severely degrades the air quality on an active channel, EDRRM triggers an immediate channel change so that no clients are stranded on an unusable channel.
Think of a city’s scheduled traffic lights as the normal RRM intervals, allowing cars (data) to move in an orderly, timed way. Normally, everyone waits for the green light, moving only at the set intervals. EDRRM is like having an emergency override for ambulances (APs in distress): if there’s a medical emergency (severe interference), the control center can change the lights to green immediately—regardless of the normal schedule—so the ambulance can take an alternate, clear route (new channel). Air Quality Reporting (AQR) acts like real-time traffic cameras detecting and reporting sudden blockages (classified interference devices) so that the emergency override can be triggered if road conditions (channel quality) deteriorate unexpectedly.

Restrictions for EDRRM and AQR update mode

  • EDRRM is not enabled by default; you must first enable CleanAir and then enable EDRRM.

  • If an interfering device is operating on an active channel and causes enough AQ degradation to trigger an EDRRM, then no clients will be able to use that channel or the AP. You must remove the AP from the channel.