Smart Mesh Changes in Zyxel Nebula 19.10: Adapting to WiFi 7 and MLO

Zyxel_Lynn

As part of the enhancements in Zyxel’s Nebula 19.10 release, the Smart Mesh feature has undergone key updates to align with the new rules introduced by WiFi 7 (802.11be) and Multi-Link Operation (MLO). These changes improve the performance and consistency of Smart Mesh setups, especially when deploying WiFi 7 tri-radio access points.

This article explains what’s changed, why it matters, and how to optimize your Smart Mesh configurations moving forward.

Key Changes to Smart Mesh in 19.10

1. MLO Is Now Always Enabled with 11BE Radios

With the latest firmware:

• The 6GHz radio only supports 802.11be (WiFi 7) mode.
• MLO is mandatory when 11BE mode is active—disabling MLO is no longer an option for 6GHz radios.

Interface Changes:

• Previously, users could toggle MLO on/off when configuring Smart Mesh.
• Now, the on/off option for MLO is removed when the radio is set to 11BE.
• Instead, users simply select the participating radios for Smart Mesh; MLO is automatically handled based on the radio mode.

2. Improved UI Layout

To reduce confusion, the Smart Mesh settings page has been restructured:

• Uplink settings are grouped together.
• Downlink settings are grouped separately.
• This eliminates unclear sequences like “uplink, downlink, downlink, uplink,” streamlining the configuration process.

How MLO Works with Default Radio Modes

In firmware 7.20, the 2.4GHz radio defaults to 802.11ax (WiFi 6) mode. This impacts the kind of Smart Mesh connections that can be formed by default.

Default Capabilities:

Radio Mode	Resulting Smart Mesh Type
2.4GHz: 11AX	Only dual-radio MLO (5GHz + 6GHz) or single-link using 2.4GHz
2.4GHz: 11BE (manually configured)	Full tri-radio MLO (2.4 + 5 + 6GHz) possible

If users forget to set all radios to 11BE, Smart Mesh will fall back to the highest compatible mode between APs. The AP with the lower radio mode will dictate the connection capabilities.

Auto-Adaptation and Compatibility Logic

• Repeater APs adapt to match the lowest shared standard across participating radios.
• Security settings are still based on the 11BE mode's requirements, even if the repeater downgrades temporarily for connectivity.
• Smart Mesh connections must mirror the radio set used by the downlink when establishing uplinks.

Real-World Example:

• A repeater connects to its downlink using 5GHz + 6GHz.
• It must use the same 5GHz + 6GHz combo when connecting to its uplink, even if all radios support 11BE.
• If 2.4GHz is not set to 11BE, full tri-radio MLO will not be possible.

Special Considerations for USG Flex and Legacy APs

Uplink AP Type	Downlink AP Type	Default Radio Modes	MLO Outcome
WiFi 7 (Tri-radio)	WiFi 7 (Tri-radio)	Default (2.4GHz AX)	5GHz + 6GHz MLO or fallback to 2.4GHz SLO
WiFi 7	USG Flex (selectable 5/6GHz)	Default	SLO (single link) or 6GHz only
WiFi 7	WiFi 6 or WiFi 5	Default	No MLO available
WiFi 7	WiFi 7 with all radios on 11BE	Manual config	Full tri-radio MLO possible

Summary and Best Practices

• MLO cannot be disabled when 11BE is active.
• UI simplified: Users now just select the radios to use; MLO is applied automatically.
• For full tri-radio MLO, set 2.4GHz to 11BE on all APs.
• Mismatched radio modes cause fallback to dual-radio or single-radio connections.
• Always match downlink and uplink Smart Mesh radio paths.