Radio frequency (RF) interference from devices operating in the unlicensed 2.4-GHz and 5-GHz bands used by wireless LANs (WLANs) is a growing concern for organizations deploying indoor and outdoor wireless networks. A variety of RF devices are now available that can cause interference, including cordless phones, Bluetooth devices, cameras, paging systems, unauthorized access points, and clients in ad-hoc mode.
Organizations need a fast and efficient method to detect, classify, and locate sources of potential RF interference. Left unaddressed, RF interference can result in low data rates and throughput, lack of sufficient WLAN coverage, WLAN performance degradation, poor voice quality, and low end-user satisfaction. This, in turn, can lead to decreased network capacity, an increase in support calls, network downtime, rising operational costs, and potential security vulnerabilities from malicious interference.
Solution
The Cisco®Unified Wireless Network supports real-time spectrum intelligence for Wi-Fi networks. This industry-leading solution detects, classifies, and locates devices causing RF interference in the unlicensed 2.4-GHz and 5-GHz bands. For this solution, the Cisco Wireless Control System (WCS) works in conjunction with Cisco Spectrum ExpertTMWi-Fi to provide visibility into non-Wi-Fi interference sources that may cause wireless performance degradation. When the source of the interference is determined, customers can remove, move, shield, adjust, or replace the interference source. This helps organizations troubleshoot the wireless network to determine the root causes of interference problems and optimize network performance.
Cisco introduced RF spectrum intelligence capabilities with Cisco Unified Wireless Network Software Release 4.1. Additional enhancements are delivered in Cisco Unified Wireless Network Software Release 4.2. To implement the full Cisco Spectrum Intelligence solution, organizations must be running Cisco WCS Software Release 4.2 or later and add a Cisco WCS Spectrum Intelligence license (Cisco Product ID: WCS-ADV-SI-SE-10) and one or more Cisco Spectrum Expert Wi-Fi 3.2 or later (Cisco Product ID: AIR-CSCO-SE-WIFI-C).
Organizations can improve coverage, capacity, quality of service, and security of wireless networks when RF interference is quickly detected and mitigated. With the Cisco Spectrum Intelligence solution, organizations can identify and resolve RF problems more efficiently, resulting in an enhanced user experience and lowered operational costs.
Features
The Cisco Unified Wireless Network includes the following features to support identification, classification, and location of devices causing RF interference in the unlicensed 2.4-GHz and 5-GHz bands.
Cisco WCS Receipt of Non-Wi-Fi Interference Alarms from Cisco Spectrum Expert
Cisco WCS can be configured to receive non-Wi-Fi interference device traps (alarms) from Cisco Spectrum Expert when a new device that is causing interference is discovered by Cisco Spectrum Expert (Figure 1). Cisco WCS can be configured to enable the reception of a trap from Cisco Spectrum Expert, issue an interference alarm, configure the severity of the alarm, and associate the alarm with a specific access point. Users can set trap filters and threshold values within Cisco Spectrum Expert so that traps are generated only for significant interference events (Figure 2). A historical view of all identified interferers is available.
Figure 2. Cisco WCS Display of Non-Wi-Fi Interference Alarm from Cisco Spectrum Expert
Real-Time Interference Monitoring of Multiple Cisco Spectrum Expert
Up to 10 Cisco Spectrum Expert tools can simultaneously interface with Cisco WCS to monitor RF interference. This allows organizations to easily detect ongoing and intermittent RF problems by placing one or more Cisco Spectrum Expert tools at local or remote locations. Real-time troubleshooting of RF problems is simplified because RF data can be collected and analyzed from multiple remote, static, or mobile Cisco Spectrum Expert tools at problem locations. Placing sensors at problem locations helps organizations improve visibility into the RF environment and deliver optimized application performance (Figure 3). Sensors can be easily managed (added/deleted) from Cisco WCS. Sensors are displayed as a client device, if connected wirelessly, on the Cisco WCS floor map (Figure 4). Detected interferer types are displayed on the WCS (Figure 5).
Figure 3. Cisco Spectrum Expert Monitoring on Cisco WCS Dashboard
Figure 4. Cisco Spectrum Expert on Cisco WCS Floor Map
Figure 5. Cisco WCS Display of Detected Interferer Types
Streamlined Searches of Interfering Devices
Searches for devices causing interference can be performed based on a variety of interferer properties and parameters (Figure 6). Interference information can then be graphed and integrated with existing Cisco WCS information for more comprehensive and sophisticated reporting, improved network performance, and enhanced network security.
Figure 6. Cisco WCS Interferer Search
Approximate Location of Interfering Devices
The approximate location of interferers can be determined by locating the Cisco Spectrum Expert with Cisco WCS, displaying the affective range of the sensors, and correlating this with the suspected interferer. This capability helps organizations more quickly find and mitigate devices causing RF interference by viewing displayed alarms and alerts (Figure 4).
Once a device is located, organizations can enforce "controlled wireless" zones by not allowing select interferers in specific zones.
Simplified Cisco Spectrum Expert Configuration
Each Cisco Spectrum Expert includes a configuration tool that simplifies the setup and operation of the sensor with Cisco WCS (Figure 7).
Figure 7. Cisco Spectrum Expert Configuration
Benefits
Benefits of using the Cisco Spectrum Intelligence solution include:
• Improved network performance and coverage because RF interference is quickly detected and mitigated
• Increased network security through quick detection of RF-level denial-of-service (DoS) attacks, nonsecure clients such as Bluetooth data bridging devices, and more accurate rogue RF device identification
• Lowered operational costs through centralized management of all RF interference, faster problem resolution times, decreased support calls, and simplified support of remote end users
• More efficient RF troubleshooting that allows organizations to quickly determine if RF interference is the cause of a WLAN problem
• Optimization of the WLAN by isolating interference from network or client problems and determining the root causes of interference problems
• Delivery of a robust wireless network foundation for mobility services and applications
Solution Components
• Cisco Unified Wireless Network
• Cisco Aironet® access points
• Cisco wireless LAN controllers
• Cisco Wireless Control System (WCS) running Software Release 4.2 or later (recommended)1
• One or more Cisco Spectrum Expert Wi-Fi 3.2 or later (recommended)1-Cisco product ID: AIR-CSCO-SE-WIFI-C
Summary
The Cisco Spectrum Intelligence solution delivers a comprehensive platform that helps organizations easily detect, classify, and locate RF interference sources. This solution supports rapid RF environment troubleshooting, simplifies Wi-Fi deployment, reduces operational costs, and enhances the user experience on the Cisco Unified Wireless Network.
To learn more about the Cisco Spectrum Expert Wi-Fi, visit:
1To implement all of the features noted in this document, Cisco WCS must be running Cisco Unified Wireless Network Software Release 4.2 or later and Cisco Spectrum Expert Wi-Fi must be running Cisco Spectrum Expert Release 3.2 or later. Cisco WCS receipt of non-Wi-Fi interference alarms from Cisco Spectrum Expert sensors can be implemented when Cisco WCS is running Cisco Unified Wireless Network Software Release 4.1.
2Cisco WCS receipt of non-Wi-Fi interference alarms from Cisco Spectrum Expert can be implemented without a Cisco WCS Spectrum Intelligence license when Cisco WCS is running Cisco Unified Wireless Network Software Release 4.1.
