The Federal Communications Commission (FCC) just proposed up to 1200 MHz of spectrum for Wi-Fi use by unlicensed devices. These devices would operate in the 6 GHz band, more specifically 5.925-7.125 GHz.
There are incumbent users of the frequency space but Wi-Fi devices utilizing that frequency, used by Broadcast Auxilary Service and Cable Television Relay Service, would only be used indoor at low power.
Having up to 1200 MHz available for Wi-Fi is great news! It provides more spectrum to a finite resource that we’re beginning to see in the 5 GHz spectrum. With 5 GHz, we are now seeing congestion. We’re limited with the amount of non-overlapping channels. And we’re unable to fully utilize 80 MHz and 160 MHz channel widths.
If Wi-Fi received 1200 MHz worth of spectrum, there would be 59 x 20 MHz channels to select from! Even at wider channels, there will be 14 x 80 MHz channels and 7 x 160 MHz channels.
The industry may be able to see the increase in throughput with more non-overlapping channels at the network operators disposal.
This is a big step forward in the right direction. Wi-Fi needs the frequency space for unlicensed devices and for the industry to innovate further.
The earliest Cisco WLC version where Cisco CleanAir was released dates back to the 7.0 days. Sometime around the year 2010. Cisco CleanAir is always on within an AP, granted if it is Enabled in the WLC. There is a Spectrum Analysis Engine (SaGE) chip built into the AP. This is important to know because it doesn’t prevent the AP from serving clients. SaGE works alongside the Wi-Fi chip. There is no affect to client throughput or traffic.
To enhance Cisco RRM’s features, CleanAir plays a critical role in allowing RRM to change channels if persistent interference is detected. CleanAir will field the appropriate algorithms to help the WLC make changes to improve an environment.
Cisco CleanAir produces two important elements:
Interference Device Report
Air Quality Index
The Interference Device Report (IDR) provides information on detected interference. It will provide a class type, what band the interference was detected on and on what channel(s), the severity of the interference, it’s duty cycle, and the interference signature.
The Air Quality Index (AQI) provides a quality score, from 0 – 100%, with 100% being good. The index will display total channel power, total channel duty cycle, the power of the interferer and total interference duty cycle.
A benefit of using Cisco CleanAir is having the ability to troubleshoot the shared spectrum remotely and without any additional hardware. A CleanAir supported access point can be utilized for this purpose. Some things to keep in mind when using your CleanAir access point for troubleshooting interference:
There are three modes:
Local – The AP will continue to serve clients on its operating channel. But any spectrum monitoring is performed on that channel only.
Monitor – The AP doesn’t server any clients but provides full time scanning.
Spectrum Expert Connect – This is a dedicated spectrum sensor and doesn’t serve any clients.
In times when the best response is to use technical support hands to troubleshoot the issue, having a method of automatically mitigating an interference issue can be highly beneficial. It can cut time to resolution down and react faster than a support team that is reactionary.
What we’d like to see from CleanAir is the ability to tell an administrator whether any action needs to be performed. While interference and air quality is determined on any given channel, does it even matter? Are any users impacted negatively? A smarter system would be able to detect interference and provide exactly which users are having issues directly related to this interferer and what kind of impact that is. And a step further would be to automatically adjust the system to fix the problem.
We’ve included some images of Cisco CleanAir in action from within Spectrum Expert and Metageek Chanalyzer.