Optimising spectrum use with ML.

Pbee · January 15

Ever since the introduction of WiFi, we've seen a overcrowding and horrible overkill of repeaters and mesh systems flooding RF spectrum. So far none of the automatic channel selection methods being used in any AP/CPE really do work.

First, the firmware of all AP/CPE's should use the right channel deployment for the region in which the device is sold/in use. Zyxel still defaults all AP/CPE to the 3-channel deploymenton 2.4GHz, which is the US FCC norm, even if the device is manufactured specifically for the EU or other markets. This can be changed right away for Nebula and Standalone modes.

And the other idea might be one for the Wifi Alliance… we need a protocol, channel that enables the an automatic orchestration of channel selection multiple AP/CPE's in the direct area. I think local ML/AI can greatly help in this, since AI is perfect for finding patterns in channel use, transmission errors, signal strengths and so on. This can be used to determine all the right parameters for optimal wifi use.
Even though it sounds easier, we really don't need Cloud services for this. AP/CPE's and wifi clients within each-others reach could exchange RF data locally and let the AP's together decide using their ML/AI what is the best channel/power arrangement on that moment. This could greatly improve wifi, especially for consumer equipment, but professional equipment can benefit just as much since we see a lot of small IT companies making the same consumer errors when installing wifi.
Current automatic channel selection in current AP's just doesn't work.

Zyxel_Tina · January 16

Hi @Pbee,

Thanks for your input!

As you mentioned, “Current automatic channel selection in current APs just doesn't work.” Could you elaborate on the specific issues you're encountering? We take this seriously and are happy to help address them.

“First, the firmware of all AP/CPE's should use the right channel deployment for the region in which the device is sold. Zyxel still defaults all wifi AP/CPE to the 3-channel deployment…” We understand your concern and will forward it to our development team for evaluation.

Additionally, for users who may not be familiar with the DCS feature, Zyxel Access Points utilize DCS to optimize wireless performance. DCS scans the surrounding environment to identify and select the cleanest, least-interfered-with Wi-Fi channel for the AP. This significantly reduces co-channel interference, leading to more stable connections and improved speeds.

We also offer advanced configurations to fine-tune DCS behavior, including:

DCS Time Interval: Allows you to regulate how often the AP surveys other Nebula devices to find less-used channels.
DCS Schedule: Enables you to set specific days and times for the AP to automatically scan and select a cleaner channel, minimizing disruption during peak hours.
DCS Client Aware: When enabled, the AP will wait until all connected clients have disconnected before switching channels, ensuring a smoother transition for users.
Avoid 5G DFS Channel / Blacklist DFS channels in presence of radar: These options help maintain stable Wi-Fi service in environments where radar devices might cause interruptions on DFS channels.

These features provide a more robust and intelligent channel selection process than what's found in basic automatic channel selection implementations.

Pbee · January 18

@Zyxel_Tina
The thing is with automatic channel switching, most AP's switch based on the signal strength of other wifi sources the AP itself can "see".

Scenario:
One of our locations a WAX650S is placed not exactly centered in the building it covers - there are practical limits.

Normally it would automatically choose channel 1 and 36 automatically. This would be fine for users close to the AP and there are no other AP's. Except we have a few client devices on the far end of the building and in that spot a neighbouring wifi signal also uses channel 1. That signal isn't detectable by the WAX650S due to the distance and a couple of walls. The far end client devices however suffer interference from that other signal. Normally in a professional setup, like ours, this is avoided because the we measured the entire RF environment first and then set the channel manually to the best compromise. But regular consumers are usually unable to do this and certainly not negotiate channels with neighbours. Plus most AP/CPE's default to channel 6 or 1 when they "see" signals on all frequencies. This create problems and adding wireless mesh systems, ISP's usually sell, makes this even worse.

If there were some way to let a client device inform the AP of that interference, it could change the channel. AP's could negotiate intelligently and wireless with each neighbouring AP about which channel, width and TX power each AP could use best. And client devices could inform the AP about all the noise they see or even relay signal data to neighbouring AP's.
This could result in a optimised channel plan, orchestrated by some local AI inside the AP's themselves.

Zyxel_Tina · January 26

Hi @Pbee,

Thank you for your feedback.

To address your concerns, please allow me to clarify:

1. Addressing Interference via Wireless Health

Regarding how an AP cannot always "see" what a distant client experiences, due to current 802.11 architecture and protocol limitations, client devices (STAs) are relatively passive and cannot yet provide a full interference map to APs. To bridge this gap, Zyxel utilizes Wireless Health in addition to the DCS feature. Instead of just scanning frequencies, it monitors client-side metrics like retry rates. If a distant client is struggling due to interference the AP can't see, the system uses these performance indicators to infer the RF environment and trigger optimization actions.

2. The 1/6/11 Channel Plan

We default to the 3-channel (1/6/11) plan primarily for two reasons:

Compatibility: Many WiFi clients do not support Channels 12 and 13. If following the 4-channel deployment (1/5/9/13) in Europe, it will likely lead DCS to use channel 13 and cause connectivity issue.
Signal Overlap: As 3-channel plans generally provide higher stability and lower inter-channel interference compared to 4-channel plans, the 4-channel plan causes adjacent channel interference because the channels overlap. This is a consideration in our specifications to minimize overlap issues.

3. The Vision of Cross-Vendor Negotiation

Under current IEEE 802.11 standards, there is no universal protocol that allows APs from different vendors to exchange RF maps or allows clients to report full spectrum data. Therefore, we focus on local metrics to optimize performance—like the Wireless Health feature mentioned above.

We would recommend reviewing the Wireless Health in Nebula to ensure the quality of wireless connectivity of those far-end clients.

Optimising spectrum use with ML.

Active · Last Updated January 15

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