"Additional 5 Ghz Radio" on all-ethernet backbone Alien mesh?

  • Whole house setup with 3 Alien Routers, all configured with Ethernet Backbone.

    The main router has a setting (under wireless) that is called “additional 5 Ghz Radio”. Do we know what this is and why this is on? And if it should be on with a 100% wired backhaul?
    I know that the Alien uses 2 separate radios for 5 Ghz (Wifi 6, 5) - however it’s not clear if this setting refers to the additional radio being open to clients, or if it’s only a setting useful for a wireless mesh (without ethernet)? I assume with ethernet backbone enabled on all nodes, there is no longer any communication between routers over wifi.
    I can see upper and lower channels on the spectrum with it on - but are they all available to clients (again, no wireless com needed for mesh backhaul in an all-ethernet environment).


  • Hi @Daniel-Osers - the Additional 5 GHz Radio is for clients that are not connecting properly to the upper band WiFi-6 radio

    WiFi-6 should be backward compatible with WiFi-5 clients, but that is not always the case and I have seen a few that just will not connect or even see the Alien WiFi-6 SSID

    The Additional 5 GHz radio should not be enabled by default, so I am surprised if yours was

    My understanding from @UI-Brett was that the Alien uses WiFi-6 for wireless backhaul

    But in your case with Ethernet backhaul the WiFi should only be used for clients

    The Alien is a little unique in that it is using a 2.4 GHz WiFi-6 radio, a WiFi-6 radio in the upper 5.8 GHz band, and then an optional WiFi-5 radio in the lower 5.2 GHz band for backward compatibility

    If you disable the Additional 5 GHz Radio then the Alien will only be using WiFi-6 in the upper 5.8 GHz band

    With the Additional 5 GHz Radio you also have the option of creating a unique WiFi-5 SSID for it, or having it mesh with the main WiFi-6 SSID, which @UI-Brett I believe indicated would include 'radio steering'

  • @Derek-Saville Hi - appreciate your reply!
    So, that makes sense - and yes, the 'additional radio' was on by default and stayed on after I paired the 2nd router then the 3rd. All that said, it would appear one should leave the additional radio on - interestingly enough my system seem to only be connecting to lower band in 5Ghz - including 2020 MBP systems, and iPhone XS. but yes, I can see upper and lower bands when I check my spectrum. I have band steering on, router steering off.

  • Hi @Daniel-Osers - if everything is working then I would never advocate messing with the setup

    Are you using 3 standalone Alien routers? (never mind, I see you had to pair them)

    Which firmware revision did they come with?
    And have you updated?

    I only have single Alien router setups, and the option is always off by default, so maybe the Additional 5 GHz radio defaults to ON for meshing?
    But that would imply they are using WiFi-5 for mesh backhaul instead of WiFi-6...

    My Aliens all shipped with v3.2.0 and the Additional 5 GHz Radio was always OFF

    Hi @UI-Brett & @UI-Karlis - should the additional 5 GHz radio default to always ON when Alien's are meshed?

  • @Derek-Saville Yes, 3 standalone Alien Routers. I assume it turned on when I paired the first (pairing has to happen in wireless mode before you switch it to ethernet backbone). It just didn't turn off after all was in ethernet mode.
    No, I could select wifi 6 (5ghz) or wifi 6 (2.4) for backhaul when I still had it on wireless, but not wifi 5.
    If with the setting on, there are more bands (and thus 4x4 and 8x8 mimo) available, it would seem you want this on in an ethernet mesh situation - but also in a single router config...
    @UI-Brett ? 🙂

  • @Daniel-Osers This setting should be off by default, I would test with it off and see if there is any issues or performance differences.

  • @UI-JT thank you and I will test that today. Can you tell me what this setting is exactly or intended for though? If it activates the 2nd 5ghz Radio for clients that would seem to be a good thing especially as my backhal won’t need to use any wireless for the 3 router mesh since I’m on an Ethernet backbone.
    I assume the setting turned on when I added my mesh points (all standalone alien routers) - adding both wirelessly and then switching to Ethernet as per instructions.
    Why should this setting be off (or on), ie under what criteria?


  • @Daniel-Osers This feature is fore clients that have issues connecting to the Main SSID, some users have previously had issues with connecting smart home devices and cameras and this additional radio allows for another SSID.

  • @UI-JT Thanks again, JT. If I can ask one followup - if that's the case I assume this is the lower band 5Ghz (Wifi 5) radio then. So turning it off means Alien stays in the upper band (8x8 mimo, Wifi 6) domain? Makes sense, but is there not an inherent advantage of having both radios active (plus the 2.4Ghz) for load balancing (4x4 + 8x8) or is it actually more effective to basically turn off one radio and 'just' have the Wifi 6 2.4/5 running? How are they being 'steered'?

    For the record, even though it's on in my setup (and was by default after I added the mesh routers) it is NOT using a separate SSID.


  • Hi @Daniel-Osers - changing the SSID of the Additional (WiFi5) 5 GHz radio is optional

    If you leave it the same as the main SSID, because the two 5 GHz radios operate on different bands (5.2 vs 5.8 GHz) the Alien can “band steer” between them as a pseudo form of “radio steering”

    You might not want that if you have clients that have trouble with the preferred upper band WiFi6 radio

    If so, you can change the SSID

    Leaving the SSID the same may allow additional coverage in congested environments, but since WiFi6 is relatively new, some WiFi6 clients may have trouble roaming between the radios if that is the case

    AmpliFi provided the additional radio for maximum compatibility if needed, but have generally advised to only enable it if a client specifically actually needs it

  • @Derek-Saville Awesome, and that makes sense - thank you.
    One interesting bit: I turned it off now and sure enough the low bands disappeared from my spectrum. That said, it's interesting that the wireless/advanced setting give you the option to select a 5Ghz channel or leave it auto - but either case ONLY covers the low bands. Seems illogical since it looks like we just turned that radio off

  • Hi @Daniel-Osers - the option of manually selecting the higher band WiFi6 channel is being worked on for a future firmware release

  • @Derek-Saville Thanks again, Derek.
    QQ: the additional radio turns itself back on all the time - and reading into older (January) threads this looks like a recognized bug. Is there an ETA for when this will be fixed?

  • Hi @Daniel-Osers - I can only speculate that the next alpha firmware build included options that need to go through FCC certification (i.e. 160 MHz channel widths, DFS, etc.), WiFi-6 certification (WPA3), and International certification and AmpliFi either ran into technical hurdles, or delays due to the global virus outbreak

    And they cannot release a public beta of something that requires pending FCC certification

    They also probably don't have the resources, especially right now, to fork their code and release interim bug fixes, which would still have to go through alpha and beta testing

    But that is all speculation on my part...

    The good news is the HD range did recently get a firmware update with FCC approved changes to Wi-Fi channels and power limits, so hopefully if all is going well, the Alien isn't far behind

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