@Alexandre. Hello. It's an interesting recommendation. Could you elaborate on why someone should avoid mixing WiFi 5 with WiFi 6 mesh nodes? My network currently consists of Deco X60 and Deco E4R, hence my curiosity. I also considered adding tri-band mesh like Deco XE75 to the existing network down the line and retiring the E4s. I would also appreciate your thought on this scenario

  @Alexandre. 
thank you!

GeneralUser-1 wrote

  @Alexandre. Hello. It's an interesting recommendation. Could you elaborate on why someone should avoid mixing WiFi 5 with WiFi 6 mesh nodes? My network currently consists of Deco X60 and Deco E4R, hence my curiosity. I also considered adding tri-band mesh like Deco XE75 to the existing network down the line and retiring the E4s. I would also appreciate your thought on this scenario

  @GeneralUser-1 

I must emphasize that these are recommendations, not requirements. Official TP-Link position is you can mix any Deco models in one Deco mesh and it'll work. I do not disagree with that position, but it depends on definition of "it'll work."  Yes, your Deco mesh shouldn't fall apart if you mix different types of hardware, but... More of this below.

These recommendations given by me on this forum are for people with different levels of IT skills, who are running Deco mesh in different environments. That's why recommendations have to be very generic. If you have good IT background, you can ignore them and will be fine - or accept the faults as yours. 

So, here they are, three of them.

In single Deco mesh:

Do not mix different Deco models

Do not mix WiFi5 and WiFi6 Deco models

Do not mix two-band and tri-band 

I myself break two rules out of three: my Deco mesh is two Deco M5s (two-band) and two Deco M9s (tri-band). As I know what I am doing and why I am doing it, that setup works for me. 

To explain reasons behind these recommendation, I'll use examples.

Do not mix different Deco models

Suppose, you have  Deco mesh with all M5s, upgraded to firmware 1.6. You decided to add Deco M4 to that mix. M4 is similar hardware specs as M5, just different shape. What could go wrong? Well, currently, Deco M4 does not have firmware 1.6 and its ETA is unknown (as is: may never happen). Check Deco M5 1.6.0 and notice features that state "This feature is ONLY supported in Mesh networks consisting of ALL Deco's with firmware 1.6.0." By adding single M4 you just had these features disabled for your Deco mesh. 

If you don't care about these features, you'll be fine. If you do, that is unpleasant surprise for you. Hence, my recommendation for someone who has Deco M5 WiFi mesh and wants to add single node to it - just buy another Deco M5 and upgrade it to firmware 1.6.

Do not mix WiFi5 and WiFi6 Deco models

When you run WiFi5 and WiFi6 nodes, you have to rely on unknown to you logic of software developer of mobile device on its WiFi connection preferences. There was at least one topic on that forum where person said their device connects to WiFi5 node further away instead of WiFi6 node that is close by.

I can understand software developer logic to choose WiFi5 over WiFi6, or to choose WiFi 2.4GHz over WiFi5. Does not mean I agree with it, but I can understand where software developers writing code for mobile devices are coming from.

Mind you, different mobile devices could have different logic. Your smartphone, for example, could happily roam to the nearest Deco with WiFi6, while latest and greatest WiFi6 capable network card you just upgraded your PC with stubbornly connects to WiFi5 Deco node further away.

If all your nodes broadcast on same protocol, such as WiFi6, then well written code for any mobile device will choose Deco node with the strongest signal, obviously. Everything else is the same: WiFi protocol, bandwidth, channel. It makes choice easy as device only needs to choose between weaker and stronger WiFi signal from different nodes.

Do not mix two-band and tri-band 

You can mix tri-band and two band, they'll work together, but you may not get what you expected. For example, what if you have Deco mesh with all X60 (two-band) and you buy tri-band X90, single node, to add to the mesh as Satellite Deco. X90 is more expensive than X60, but it'll not deliver much faster Internet than X60s in this setup. You wasted your money, obviously. Should have bought X60 instead.

Let' say you've made that X90 you Main Deco, as TP-Link recommends. Still, your mobile devices connected to Satellite Deco X60 in your bedroom, where you need Internet speed the most, don't see the difference. Why, then, spending money on X90?

An opposite example: I have two units Deco M9Plus. They are tri-band. Satellite Deco M9 delivers steady 450Mbps. I want to add another two Deco nodes to the mix and I buy Deco M5 two-node set, saving few dollars comparing to M9.

Deco M5 is two-band. Its top speed at my house is 250Mbps, half of what M9Plus could have delivered. Was it good purchase or should have I bought additional 2-node M9Plus set instead?

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Hopefully, that explains.

  @Alexandre. Thank you so much for your response. Really appreciate your point of view. The lack of features across the network while adding different models to the network certainly is annoying. I cant say I am experiencing this myself, but it's certainly something to keep in mind as I have both V2 and V3 versions of Deco X60. V3 being used as the main Deco with those added features Home Shield and AI driven Mesh (I still don't know how exactly this works).

To me personally, better connectivity and reliability across devices is far more important. I have noticed that improvement when I started adding X60s with WiFi 6 to areas with heavy usage and pushing E4s to outer areas with fewer connectivity. So far this has worked great.

I had the Tri-band (XE75) update in mind, particularly for Main Deco and secondary deco (its what I call the deco to which all other Deco's are connected to, more like an intersection). But would it improve anything? Hard to say.