@TP-Link   Sorry for the confusion - the primary issue is with Download speed.  I have made some minor adjustments to the configuration of my network and also now have separate 2.4GHz and 5GHz networks.  The 5GHz seems to be working better and I ma getting consistently around 40+Mbps download with little variation, and upload around 30Mbps.  The 2.4GHz network is the one that is now varying significantly.  Sometimes I can get in the region of 30Mbps Download, but more often will be around 10Mbps or less and this variation will be even when I am within sight of the master Deco unit 10 ft away.

As a description of my set-up

I have a Router from my ISP - I have disabled WiFi on it.  This is connected to the Master Deco unit (E4R) then a Slave Deco is a plug in extender M3W.  Also connected to the master I have a mini switch for wired connections to other equipment in my home (Sonos Boost, PC, TV, BluRay Player, NAS Drive storage)

I have connected my tablet/laptop to the 5GHz network and that now seems fine - but we have issues with the Sonos that keeps getting buffering issues via the 2.4GHz network.

I also have issues where the cabled PC going via the Master Deco is reporting only 14Mbps Download, but 30Mbps upload.  As this is fully cabled I do not understand this.  If i connect directly to my ISP router I can get 50Mbps download - but I do not want to do that as I would loose the networking capability

@TP-Link 

Hi, I have heard no other suggestions from you with regards to this.  I have been doing some other work to see if I can improve things, but with moving locations of the master and salve I have been unable to improve the situation to give satisfactory service.

On my 5GHz network i can achieve around 30 to 40Mbps based on the Ookla speed test app. If it am close to the master unit this can get close to the ISP router speed of around 60/70 Mbps.

On the 2.4GHz network through I very rarely get more than 25Mbps even when in the same room as the Master unit.

I have been doing some further reserach and believe what I really need is a combined powerline and mesh network and this should get me improved coverage around the house.  However the problem I have for this is that I have an extension which has a separate mains circuit, and so the powerline aspect will not work.  However I do have an Ethernet cabled connection between the main part of the house and the extension. Do you have a solution I can use to have a single SSID wifi across main house and extension using powerline in both parts and use the Ethernet cabling to join them?

Thanks,

Dave

@DaveP67 

I may be able to recommend something for WiFi coverage in the house and extension, but I'll need the following information from you first:

1. Do you run Deco mesh in Router mode or in Access Point mode?

2. You have Ethernet cable layed between main house and extension. What is this cable connected to in main house: to switch and to rest of home wired network, or it connected to nothing at all and just unused cable?  

3. Is your M3W Satellite Deco unit in main house or in extension currently?

@Alexandre. 

1 this is run in Wireless Router mode ( connected to my ISP wireless router, where I have turned its WiFi off)

2 the ethernet cable is connected to a switch that has a number of wired devices connected to it.

3 the M3W is in the main house

I have been looking at changing to use powerline option with the powerline/wifi units with the master of that system connected via the ethernet cable to my ISP wifi router.  What I am not clear on is if the "wifi clone" functionality will work with any wifi source or just with TP Link wifi routers?  If this works , then I have the wifi router in the extension, and the powerline wifi units covering the main house.

@DaveP67 

If you have Ethernet cable connected to your home network, there is a simple solution. Buy single Deco unit, such as Deco M5, connect it to Ethernet cable in your extension. That Deco unit will become part of Deco mesh, will run with same SSID.

This should work with Deco mesh in Access Point mode regardless of network layout, but if you run Deco in Router mode network layout is important. See this article for more information: General questions about Ethernet Backhaul feature on your Deco

If you have ISP router, I would suggest switching Deco to Access Point mode. Not only it'll give you more flexibility in wired Deco units deployment, but as a side effect might improve Deco mesh WiFi performance.