Cisco Catalyst 9800 Series Wireless Controller Software Configuration Guide, Cisco IOS XE 26.1.x

Cisco ISE systems

Updated: April 10, 2026

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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 ISE system is a wireless spectrum management solution that

proactively monitors and manages challenges caused by interference in a shared wireless spectrum
uses Cisco CleanAir-enabled access points and controllers to detect and analyze native and foreign interference sources, and
enables both manual and automated remediation to optimize wireless network operation.

Table 1. Feature history for 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.

Components of Cisco ISE 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, , and .
Management platforms: provide centralized management and visualization of spectrum and interference data forwarded by the controllers.

How Cisco CleanAir systems detect and respond to interference

Always-On spectrum awareness: Cisco ISE-enabled APs scan the industrial, scientific, and medical (ISM) bands, identifying and evaluating all radio devices that may cause interference.
Unified control and interference intelligence: The controller controls the access points and displays the interference devices.
Actionable Insight for Every Interferer: For every device operating in the unlicensed band, Cisco ISE 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 ISE 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.

Wireless LAN systems use unlicensed 2.4-GHz and 5-GHz ISM bands, which are also shared by devices such as microwave ovens, cordless phones, and Bluetooth equipment. These non-Wi-Fi devices can disrupt network services including voice-over-wireless and IEEE 802.11 communications. Cisco CleanAir systems detect such interference and help mitigate its effects.

Table 2. Cisco CleanAir-related terms
Term	Description
AQI	Air Quality Index. The AQI indicates air quality based on RF interference. An AQI of zero is considered poor, and an AQI greater than eighty-five is considered good.
AQR	Air Quality Report. An AQR shows total interference from all sources, including major categories. The system sends an AQR every 15 minutes and every 30 seconds in Rapid mode.
DC	Duty Cycle. Indicates the percentage of time your device uses the channel.
EDRRM	Event-Driven RRM. When needed, EDRRM enables your access point to skip normal RRM intervals and immediately change channels.
IDR	Interference Device Reports that an AP sends to the controller .
ISI	Interference Severity Index. The ISI is an indicator of the severity of the interference.
RSSI	Received Signal Strength Indicator. RSSI measures the power in a received signal. It indicates the level detected by an access point from an interfering device.

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

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

Configuration: Configures Cisco CleanAir capabilities on the APs.
Detection: Cisco CleanAir-enabled APs continuously scan the wireless environment for interference sources and assess air quality.
Reporting: APs generate reports such as Air Quality Reports (AQRs) and Interference Device Reports (IDRs), which summarize detected interference and air quality indexes.
Aggregation: Wireless controllers collect AQRs and IDRs from all APs, process the data, and store it in relevant databases.
Analysis and Response: Controllers use built-in mechanisms (like Radio Resource Management) to mitigate interference and maintain optimal RF conditions.
Advanced Services: MSE tracks interference devices over time and location, merges data from multiple controllers, and provides comprehensive threat detection with adaptive Wireless Intrusion Prevention System (WIPS).
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
SE-Connect : Use this mode to connect Spectrum Expert on a Microsoft Windows XP or Vista PC to a Cisco CleanAir-enabled access point and display detailed spectrum data. The application connects directly to the AP and bypasses the device. In SE-Connect mode, the AP does not provide Wi-Fi, RF, or spectrum data; it does not serve clients. Use this mode only for remote troubleshooting. You can have up to three active Spectrum Expert connections.

Only Cisco Catalyst 3850 and Switches can function as Mobility Agents.

Cisco Catalyst 3850 Switches, and Cisco 5760 Wireless LAN Controllers can function as Mobility Controllers.

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.

In the 4800 AP, slot 1 is dedicated to 5 GHz and cannot be moved to monitor mode. Slot 0 is an XOR slot and can be set to monitor mode, 2.4 GHz, or 5 GHz. Slot 2 is dedicated to monitor mode and will operate in 5 GHz. When AP monitor mode is enabled, slot 2 is disabled because a monitor radio is already available for both 2.4 and 5 GHz. The 3700 AP has dedicated 2.4 GHz (slot 0) and 5 GHz (slot 1) radios.

Do not connect APs in SE connect mode directly to any physical port on the controller.

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

Difference between Wi-Fi chip-based RF Management and Cisco CleanAir


Feature	Wi-Fi Chip–Based RF Management	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.

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