cancel
Showing results for 
Search instead for 
Did you mean: 
Annie95
Beginner
2,486 Views
Message 1 of 12

Basic question about BT Whole Home

We are looking at the BT Whole Home system to get better coverage of our house, but there is something I don't understand about it.

 

When we set up our first router we had to avoid the channels used by our neighbours because they would interfere and reduce our signals. But as I understand it the Whole Home puts out three signals on the same channel. So if I have a phone or laptop halfway between two of them the signals will interfere with each other. Isn't this the same as being on the same channel as our neighbour? Can someone explain why this isn't a problem please. Thank you. Smiley Happy   

0 Ratings
11 REPLIES 11
flamethrower
Aspiring Expert
2,468 Views
Message 2 of 12

Re: Basic question about BT Whole Home

Hi Annie

 

Welcome to the forums.

 

BT Whole Home is a mesh networking solution. It has three basestations operating on the same channels in the 2.4GHz and 5Ghz bands. There will be some interference between transmissions on these channels, but there are few mitigating factors.:

 

1) signal strength decreases as the square of distance so if there is a reasonable distance between the basestations the interference is less.

2) in general 5GHz signal strength diminishes more quickly than 2.4GHz so there can be less interference here. Since 5GHz offers more bandwidth this is super useful.

3) they employ beam forming which provides creates a stronger signal in a particular direction rather than just broadcast.

 

 

Mesh is a convenient solution for most people. Devices handoff transparently and are unaware of the multiple base stations. Even though there will be some interference, it's unlikely to have a major impact on how much data your devices can consume particularly at 5GHz (wifi bandwidth might be around 500Mbps, Infinity 2 fibre is 80Mbps, 4K video from youtube is max 15Mbps).

 

Observationally, many homes can get better wifi by relocating their base station strategically, e.g. the master socket is often located in the corner of a house so the router goes there, with wifi disabled, and a separate wireless access point goes in the middle of the house using either ethernet or homeplug to connect the router and the wireless AP. A good location for the AP can be used using a wifi analyzer app on a mobile device. This requires more patience and expertise to set up than mesh.

 

Hope this helps

P.

 

 

0 Ratings
Annie95
Beginner
2,446 Views
Message 3 of 12

Re: Basic question about BT Whole Home

Thank you very much Smiley Happy

It just seems strange that interference from a neighbour is bad, but interference from your own system is not so bad. I think we will just have to try it and see.      

0 Ratings
smf22
Recognised Expert
2,429 Views
Message 4 of 12

Re: Basic question about BT Whole Home

When you said "as I understand it the Whole Home puts out three signals on the same channel" have you read that somewhere or have you drawn the conclusion as there are three discs?

 

I don't use BT Whole Home WiFi so don't know for sure, but I would hope it's intelligent enough to avoid each disc using the same channel. I have a 'controller' based WiFi solution that's similar to the BT mesh solution in that there's some back end intelligence, and what I see is that the two access points are using different channels for the 2.4 and 5 GHz WiFi.

 

wifi.png

 

I would hope the BT mesh solution operates in a similar way so avoiding cross channel interference.

 

Regards

0 Ratings
Annie95
Beginner
2,410 Views
Message 5 of 12

Re: Basic question about BT Whole Home

Hi smf22

 

Yes I had assumed that all the disks were on the same channel. I'm afraid my knowledge of these things is limited to A level Physics, which didn't cover WiFi. Smiley Sad  But as I understand from playing with our present router there are only three separate useable channels at 2.4GHz. If the Whole Home can use up to four disks, where do they all go?  There are more channels at 5GHz of course.  

 

If someone withe practical experience of the system could explain, I would be very glad to hear it. 

0 Ratings
Distinguished Sage
Distinguished Sage
2,405 Views
Message 6 of 12

Re: Basic question about BT Whole Home

If you have an Android phone you can check what channels are transmitting with the WIFI Analyzer app by farproc.

 

0 Ratings
smf22
Recognised Expert
2,399 Views
Message 7 of 12

Re: Basic question about BT Whole Home


@Annie95 wrote:

Hi smf22

 

But as I understand from playing with our present router there are only three separate useable channels at 2.4GHz. If the Whole Home can use up to four disks, where do they all go?  There are more channels at 5GHz of course.  

 

If someone withe practical experience of the system could explain, I would be very glad to hear it. 


Whether a WiFi solution allows the selection of all 2.4 GHz channels or, as the latest BT Hub does, limits selection to channels 1, 6 and 11, the reality is that use of channels other than 1, 6 and 11 can mean adjacent or cross channel interference. The post Why Channels 1, 6 and 11? is fairly short and explains why that is.

 

In terms of when there are four disks, let's assume the following setup.

 

 

Disk 1           Disk 2           Disk 3           Disk 4
Ch.1             Ch. 6            Ch. 11           Ch. 1

 

 

If the fourth disk were only within WiFi range of Disks 2 and 3, then whilst it's using the same channel as Disk 1, there would be no interference. In the event that Disk 1 and Disk 4 were within WiFi range there would only be interference when there are clients connected to Disk 1 and 4 that were sending/receiving simultaneously.

 

As @licquorice mentioned, get yourself a WiFi analyser and take a look at the WiFi signals around you. You'll likely find that the problem won't be as bad as you imagine. If you want a reasonable analyser for Windows and OS X, the site I referenced above produce inSSIDer which is free for non-commercial use up to an including inSSIDer version 3. Google for it as the download is not from the metageek website.

 

Regards

0 Ratings
Annie95
Beginner
2,383 Views
Message 8 of 12

Re: Basic question about BT Whole Home

I do use inssider on a phone with our existing router and as I said above I do know that there are only three usable channels in the 2.4GHz band.  That's how I found the best channel to use.

 

But we are looking for a solution that will cover all round our house and that means more that one transmitter. We have looked at the mains signal devices but the Whole Home seems a better arrangement.

 

Since we have very strong signals from neighbours on two of the channels it would be interesting to know how the Whole Home would decide which channels to use for its three 'disks'.

 

Has anyone with one of these systems in use anything to add? 

  

 

0 Ratings
flamethrower
Aspiring Expert
2,362 Views
Message 9 of 12

Re: Basic question about BT Whole Home

From what I read, I understand BT Whole Home is documented as supporting 1 channel in each band, e.g.

 

https://community.bt.com/t5/Connected-Devices-Other/Whole-Home-and-Intelligent-Channel-Selection/td-...

http://www.dreamgreenhouse.com/reviews/2017/wholehome/index.php

 

If this were not the case, it would be good, but I think there may be some conclusion jumping going on here. The multi-channel per band might be more an enterprise feature than home.

 

There are different mesh standards. BT Whole Home is documented as using 802.11 k/v. Google WiFi uses 802.11s. I haven't reviewed these yet, but they may shed more light on this in the absence of channel scan data.

 

0 Ratings
Annie95
Beginner
2,351 Views
Message 10 of 12

Re: Basic question about BT Whole Home

Well thank you for those links. From what they say it does seem that all the disks use the same channels.

 

I don't think I know enough yet about the system, or have been persuaded sufficiently, to be confident enough to invest in the system.     

0 Ratings