@sapinto 

Hey

I would start with finding out how your P9 in the basement is connected to the Main Deco, looking in the app should tell you this.

If its using powerline only then that could be an issue as the WiFi cant penetrate, therefore a new node wont make a difference sadly.

If its powerline and 2.4ghz, depending on the signal and what speeds you are looking (guessing 100mbps), then moving to WiFi6 deco (X range) may help

If its 5ghz nad 2,4 strong, then deffo WiFi 6 would help

Have you tried running the network optimiser?   that would change the channel you are on and might overcome the signal loss, what you say it does sound like the PLC is struggling over the older cables and WiFi is weak..  change of channel may help, otherwise a cable sadly..

  @Philbert Thank you so much for the reply. 

Up until a few weeks ago, it has always been connected with PLC + WiFi, right now it's only WiFi (no PLC) with both 5GHz and 2.4Ghz, but only weak signal (1 bar).

I'm pretty sure I've seen the "Network Optimization" feature in the app in a previous version but can't seem to find it in the most recent version, from what I've gathered online I'm not the only one with this issue, didn't find a solution for it though. 

Would you say then, that the one X series node would help? Is there a way of getting just one of them? Or does it have to be a 2-pack?

Thanks for your support.

  @sapinto 

Hey

Network Optimisation should be under the MORE section in the app, note however you need to be logged in as the owner and not a manager if memory services me correctly.   That might help your issue, but reading your post of 1 bar, umm....

Do you have android by any chance?  If so download an app called WiFi Analyser and pop down to where the basement P9 is.  Power off the basement P9 and open WiFi Analyser, see what signal in -db you are getting down there and then you are in a better position to make a decision.   1 bar doesnt really indicate much tbh..   -db is the correct way

In short the following is roughtly the ranges

-30   AWESOME

-40   Superb

-50   Good

-60   Average

-70   Weaker

-80   DEAD

You ideally are looking for a signal around the -40 to -60, at -65 it might be possible.  Any lower than that and its really going to be slow / intermittant.  

In answer to your X range question... No sadly.     WiFi is a weird thing in that you cant extend distance, signal is the same regardless of the version of the WiFi used unless you start to introduce massive antenna and lots of gain.   Yes WiFi6 (X Range) is faster in how it handles data using the signal, but laws of physics mean it wont go any further distance.    That aside, if you are losing 75% of the signal regardless...  75% of 1200mbps WiFi 6 is better than 75% of 866mbps WiFi 5

However.. you would need to change BOTH the main and Basement node, as both need WiFi6 to be able to communicate at 6 speeds, otherwise they talk at the slower speeds.  

  @Philbert I'm logged in as owner, and I'd already checked the MORE section, but there doesn't seem to be aything there not even when I write it down in the search bar (photo below)

I'll try the test with WiFi Analyser later in the day when I can do testing uninterruptedly, for reference with the basement P9 connected I get -55 dBm in the one I'm connected to. The one bar I mentioned earlier was from the basement Deco on the app, not my own phone, just to be clear.

I found your range extending paragraph a bit confusing to be honest, I know extending WiFi range is possible by adding more nodes, otherwise I couldn't be using WiFI at all in the basement. I know that while extending the range there are severall factors that will cause losses, in my case I believe the main factors are the old electrical installation and the walls / ceiling themselves.

But perhaps I didn't make myself clear as my intention was to add a node and not replace one, I'm aware that to comunicate at WiFi 6 speeds, all nodes must be compatible with WiFi 6, but my intent was that by adding a middle node between the main and the basement, the signal would be stronger and more stable in the basement, as to what Deco to use it wouldn't necessarily have to be WiFi 6 as I wouldn't take that much advantage from it --> would I still get WiFi 6 speeds when connected to that one node though, that's something I'm not quite sure? 

Even though I'm an electronics engineer I'm still learning about these devices, as they're not as straight forward as advertised, I used to think that PLC extenders were the jack of all trades and would solve all my issues due to how they're advertised, and partly they kinda did.

But recently I learned that at least TP-Link ones still need the slightest bit of WiFi to work, so the powerline feature can never work on its own, making it not so amazing after all, also they are severely affected by the electrical installation quality and electrical network variations, so even if they work at the moment they're not guaranteed to work indefinitely, that has to be true since I didn't make any changes in my home or added more devices permanently in outlets whatsoever. 

So the bottom line is, WiFi speeds aside, is there a chance to improve my network by adding a 4th node based on a more powerful extender?

  @sapinto 

Hey

Yeah the P9s kinda blend the PLC and WiFi into one, from my experience you need a bit of both for these to work correctly (as you stated).  That would be my concern with adding an additional node, unless you have a route around the problem using a less concrete / rebarred route then adding an additional node hop likely wont help.  I will try to explain a bit

Each time you add a node it increases latency by 50%, which slows throughput.   As you are now hopping through a middle node, the distance and time is x2 so speed is 1/2 overall.   Therefore deco will always prefere to go direct to the main deco as its a single hop, the algorthm with always perfer hops over signal.   In simple terms it will take 75% loss direct to the main deco every time   vs   66% loss +50% hop loss..   hopefully that makes sense?   In short, my concern would be that the new node you buy would be ignored by the basement node, as it would prefere the direct route and therefore you really havent fixed anything.  

OK but considering that, some of the deco (M5 for example) you can tell it what node to connect too.. so.. if you moved your P9 downstairs into a new position closer, you could get a M5 and tell it to use the P9 as its node.  Place this M5 in where the P9 used to be, old P9 is now a mid repeater.... if that is possible.? 

PLCs are hit and miss tbh.   They do work with new or good wiring, but if its older copper these can be questionable, seen it before.   They are far from get out of jail free soliutions

What I was trying to say about extending is that it can only be done by additional nodes.  There is no 'more powerful' deco that will give you an additional range or better signal strength, sadly.   All deco are built to roughtly the same EIRP (power for want of a better word) and therefore an M9 will transmit the same distance as a X90.   That considered a WiFi 6 connection between the nodes (x Range Deco) would offer you faster speeds at the same signal strength. 

Its worth noting that 2.4ghz is better at penetrating walls / floors vs 5ghz so the increased speed of Deco X using 2.4 may be an answer for you.   Again check this signal on your Android for 2.4 vs 5ghz.    If 2.4 is noticably better, then WiFi 6 can get upto 600mbps over 2.4ghz and that might be your answer

  @Philbert ok I see what you mean now.

If, in your experience, no Deco is more "powerful" in extending than the other, and the nodes always prefer to connect yo the main one, than adding a middle probably won't solve all my problems, even in that case of using an M5 for example I believe the improvements would be marginal. I may however consider investing in an extra node to improve connection in my kitchen and backyard, because I have previously tried putting the basement Deco there and it worked very nicely, wouldn't solve the basement issue though.

In the meantime I tried to do more testing with the WiFi Analyzer app and seems the signal strength is a bit better on the other side of the basement, still I believe I wouldn't benefit in connecting the Deco there because it's further away from my office having more walls in the middle. 

Also after many network reboots, (still no optimisation tool in the app), and node reprovisionings I think I finally achieved a somewhat stable connection for the time being (getting 50 to 60 Mbps in the basement Deco).

But in the end, given the history of my network I don't think this will last, and I really need to come up with a better solution somehow. 

I have 2 final questions:

- Assuming I can somehow get some ethernet cable over to the basement and connect the main node to the basement one, this would guarantee almost the same speeds as I get in the main one correct?

- My ISP router still has its WiFi turned on, even though the main Deco is connected to it in bridge mode at the time I couldn't turn off the main router's WiFi because the router settings wouldn't allow it, although according to the WiFi analyzer app that WiFi is on a different channel than the Decos. Does this pose signficant interference to the overall network?

  @sapinto 

Yeah you are not the first one to come across this issue before, had a few customers where PLC and WiFi just wouldnt cut it.    PLC also tops out around 200mbps in real speeds, while that is usable, lot of connections now are much faster than that, one of the reasons MESH has taken over.

Ok so in answer to you questions

- Assuming I can somehow get some ethernet cable over to the basement and connect the main node to the basement one, this would guarantee almost the same speeds as I get in the main one correct?

Yes.. if you can get a cable from the Main Deco down to the Basement Deco they will connect and communicate at 1gbps, so when you are near the basement deco it should offer you as fast as it can over WiFi, then use the cable to 'trunk' back to the main Deco.   In normal AC wireless (wifi5) this should be around 500mbps which is likely faster than your internet speed. 

- My ISP router still has its WiFi turned on, even though the main Deco is connected to it in bridge mode at the time I couldn't turn off the main router's WiFi because the router settings wouldn't allow it, although according to the WiFi analyzer app that WiFi is on a different channel than the Decos. Does this pose signficant interference to the overall network?

It could possibly cause some interference, but this is likely not a deal breaker.    Deco works on channels 36 40 44 and 48 out of the box, these are the most common channels if honest.     Each channel is 20mhz wide so to get the fastest speeds Deco will bond 4x of them together (80mhz), this means it will use channels 36 upto 48 as one large channel.   Should the ISP router be doing the same it may cause some interference, you could try setting the ISP router to channel 52 or higher.. or reduce its channel width to 20/40mhz and that would limit the interference.   Provided that is a possibility of course.

  @Philbert understood! 

Still no idea how I'll pass the cable but seems to be my only reliable option. 

Thank you once again for your help. 

Best regards

  @sapinto 

More than welcome

Yeah, while WiFi is handy.. you can beat a good old cable.   If you are running cable Cat6 would be best, that will work upto 10gb over a 50m stretch and give you some upgrade path in the future.   Cat5e will also work, but you will be limited to 1gbps

Best of luck :)