FTTC - Noise

I'm having issues with both my internet connection (and other radio devices such as my Evohome heating control system).

These issues seem to start in the evening for FTTC and are worst around 9-10pm. The Evohome is also problematic in the evening, however shows oddities all the time.

From my internet connection point of view I first notice that everything seems to slow down in terms of response time. Websites seem to stall loading for quite some time. Performing speed tests seems to show really low speed of ten to a couple of hundred kb's for 10-30secs then ramping up to normal speed.

What I have noticed is the the Noise Margin drops significantly when experiencing this problem but only for down not up. By example my usual noise margin hovers between 6.1 - 6.5 db throughout the day. However, when these annomolies happen the noise margin drops down to 2.3 - 2.4db. Upload remains at 5.8-6db

With regards to be Evohome (which operates on 868mhz) I am finding messages are not getting relayed from controller to relay (however are to the TRV's). This leads to house overheating, but the connection reported back by the devices shows 5/5 signal (and happens even if they are next to each other). Honeywell believe there is interference, which makes sense.

I have smart meters and notice the zigbee receiver complaints about signal loss, but then magically it comes back (even when quite close to the meters).

I am on a laptop connected by WiFi over 5ghz and the slowness is still present.

Any ideas what could be causing such a massive amount of interference to be causing issues across:

FTTC power levels
868mhz evohome messages
2.4ghz WiFi zigbee comms
5ghz WiFi my laptop

Apologies if the posts a bit loose on details and a bit sporadic. At first I thought it might be the construction of the house, but that wouldn't effect the FTTC surely at random intervals? Honeywell said they have seen fringe examples where smart meters have caused problems to their devices. EON refuse to back down and won't let me (nor them) turn the smart meters off to check.

Are you able to turn off the Evohome?

If so, I suggest you do so as soon as the FTTC problems start, and see what happens.

If there is interference behind this it is across a very wide frequency range since maximum VDSL2 frequency is 17 MHz.

Unfortunately not very easily as i'd have to go round and remove 12 TRV's, turn boiler off so relay could be disabled and take batteries out the controller meaning i'd lose all the settings on the controller (which frustratingly takes ages to setup) so we'd be without heat for while.

I will be able to try this, but unfortunately not quick enough to do it when problems start as the complexity of all the devices.

In reply to a post by MrSaffron:

If there is interference behind this it is across a very wide frequency range since maximum VDSL2 frequency is 17 MHz.

Have you ever heard of anything like this before (such a wide range that is?)

After many hours on with Honeywell they were very stumped. These issues might not be related however, it seems like this house really doesn't play well.

The only recent changes (as unfortunately not lived here long) made by me which could be related was:

- Longer tails placed on electric meter to extend consumer unit (cable is run through middle of the exterior wall approx 3.5m run)
- Smart meters

Oh, and a really long shot. The FTTC cabinet is placed very close to a weather / pollution monitoring station and slap bang next to a Virgin Media cabinet.

Edited by gary333 (Mon 04-May-20 22:59:34)

At around 11.10pm tonight the noise margin pops back up to 6.3db and the problem with internet not reacting seems to have gone away - until next time. All ideas welcome

If proximity to Virgin cab was issue would not stop at 11:10pm

Similar with monitoring station as usually on all the time.

You are looking for something that switches on/off by the looks of it.

Wideband interference means a FM or shortwave radio might be useful to help track down the noisy device (devices) and turn things off in turn until you finally pin down the culprit

General rule is if this was not an issue before last electrical change to suspect what ever was added/changed is the culprit

Try Mr.S’s suggestion, go buy a cheap battery powered MW radio. Have it tuned to about 612 MW and have a listen around the property .....
I’d suggest trying when there is no interference apparent ... then again later when there is ....
Most likely symptom will be a pronounced ‘growl’ on the radio. If you pick one up, try turning stuff off at the mains till you locate a possible source.

**Hunting REIN isn’t an exact science**

Cheers both, will give that a go. Is there any way of checking outside to see if the problem is external, would it still be the radio scenario?

Although the noise margin increased to 6.3db at around 11:10pm last night. I noticed the WiFi was having problems I described above and things not loading (until I turned wifi off on each device and back on, or restarted them).

This problem was happening until well after 12am (after which I went to bed).

I got an email from the Evohome @ 4:30am saying connection restored, so after checking the TB connection quality monitor can see it was out for a few hours in the early hours.

Edit - Added TB Monitor link My line

Edited by gary333 (Tue 05-May-20 07:41:23)

See if you can find a nearby radio ham. Either (1) they will have the equipment to help you locate the problem, and will be delighted to help you do so; or (2) they will be the problem

I remember reading about a similar issue on here a while back and it turned out to be the neighbours faulty flourescent garage light putting out interference.

Easiest way to to rule out your property is to switch off everything at the fuse board/consumer unit.

In reply to a post by Zarjaz:

Easiest way to to rule out your property is to switch off everything at the fuse board/consumer unit.

They might find it difficult to get their modem to sync to test if this made any difference

Have you spoken with neighbours, both immediate and say 3 doors away in both directions?

Do they have problems with their connection or not?

If those immediately next door do,maybe just one side do have, but no one else, the problem could be in one of te two properties. IF neighbours several doors away are also seeing it ten the problem could be outside the properties and an external source.

Can you keep an accurate log of when it start and ends?

I helped resolve one problem where it was a radio station that only broadcast for a few hours every evening - their location was 20 miles away however they used a directional transmitter very close to where te problem was being seen.

Fair point ..... had forgotten I have a HHT which needs no juice to sync

Should be possible to rig up a 12V battery to the ONT power input - even for those which didn't come with their own BBU.

NOTE: Talking about a FTTC service here not FTTP.

Are you having problems every night, or just some?

The reason for asking is that Amateur radio operators have contests in the evenings, but not every evening. I used to see issues similar to what you are describing when there were 80m contests on.

The FTTC issues are not every night. Maybe happens (at least me noticing it) maybe once / twice per week - however i'll try and keep a log.

WiFi interference seems more common daily (i.e. it's acting up. but the power levels remain fine). The issues with the Evohome having unsuccessful communication if message are pushed out all at the same time (i.e. shut system down) is present all of the time. The comms issues from the zigbee also seem to be very common if the device is moved more than a couple of meters from the exterior wall where the meters are located.

Appreciate there could be multiple sources here as power levels are fine most of the time whereas wifi is intermittent.

For reference my house is a conventional build (brick and tiles). Exterior brick with blockwork being concrete, internal garage (conversion) is thermalite. The internal walls are mainly 15mm plasterboard walls. Most of ceilings between ground and first floor do have resilient bars in (a thin metal bar that holds the soundboard plasterboard up. 30mm living room, 15mm all other rooms. All plasterboard walls are filled with rock wool too of between 50mm to 140mm thickness.

Hmmmmmm .... reading your last post, I’m doubting REIN now. And if it is, you’ll be very lucky to locate it.

If you compare your dates/times to the calendar here: https://www.rsgbcc.org/hf/ and see if they correspond (particularly 80m). If they do you probably want to see if there is a local amateur radio operator. I can help you with this if needed.

In reply to a post by Zarjaz:

Hmmmmmm .... reading your last post, I’m doubting REIN now. And if it is, you’ll be very lucky to locate it.

oh dear . Your ideas are much appreciated though. I will give the MW radio a go. Is MW labelled as AM on some radios?

I do notice that there a lots of WiFi networks visible where I live. When upstairs some of the other networks appear to be more powerful than my own network even though the houses are all detached and spaced apart so i'd have expected mine to be more powerful.

The reason I was thinking interference from other sources than just Wifi was due to the issues I was getting with Evohome which is totally different frequency - but still struggling with the same comms issues my wifi is.

Sorry for the ramblings.

Cheers for this. I'll keep a track of them dates and if I see drops in performance & power.

Last night started @ around 7:30pm and I can see on their website they have
Mon 4 May.
1900-2030
80m CC SSB
100W-A 10W-A

For reference. Would I expect to see large vertical aerials on peoples houses / sheds if they were radio enthusiasts? A couple of streets away is someone with an antenna. I think they might have something to do with taxi radio comms.

In my previous house around the corner I used to get a similar issue (of stuck websites / videos randomly stopping) on Virgin Media, however just assumed this was the router being useless. This also used to happen later in the night coming to think of it but nowhere near as common as it is here. There was only one or two other wifi networks visible at that property too.

Additionally. I had Virgin Media here too and also saw large speed drops around the house even though signal on device remained strong.

Edited by gary333 (Tue 05-May-20 12:53:44)

In reply to a post by gary333:

I do notice that there a lots of WiFi networks visible where I live. When upstairs some of the other networks appear to be more powerful than my own network even though the houses are all detached and spaced apart so i'd have expected mine to be more powerful.

Yes, different makes of router can achieve more transmission, depending on the design. Most of the ISP provided routers are quite cheap, some of the third party ones can achieve more.

I live in a block of flats where 2.4 GHz WiFi is unusable due to the volume of people using it. Before lockdown it was okay, as most people were not at home - you could see network names, but they were not in use. Now they are in use, throughput on my 2.4 GHz has dropped to 50 Mbps with lots of stalling. On 5 GHz there is a lot less range, so I can get coverage of my flat, and I mostly get the full 200 Mbps of my connection.

I have Hive which also uses the Zigbe system, and I've not had any problems with that. If you have interference across all those bands, it make me wonder if you are a) near an airport, or b) near anything military? Wide band RF interference is very rare and you may need a guru, or talk to Ofcom ??

In reply to a post by jchamier:

In reply to a post by gary333:

I do notice that there a lots of WiFi networks visible where I live. When upstairs some of the other networks appear to be more powerful than my own network even though the houses are all detached and spaced apart so i'd have expected mine to be more powerful.

Yes, different makes of router can achieve more transmission, depending on the design. Most of the ISP provided routers are quite cheap, some of the third party ones can achieve more.

I live in a block of flats where 2.4 GHz WiFi is unusable due to the volume of people using it. Before lockdown it was okay, as most people were not at home - you could see network names, but they were not in use. Now they are in use, throughput on my 2.4 GHz has dropped to 50 Mbps with lots of stalling. On 5 GHz there is a lot less range, so I can get coverage of my flat, and I mostly get the full 200 Mbps of my connection.

I have Hive which also uses the Zigbe system, and I've not had any problems with that. If you have interference across all those bands, it make me wonder if you are a) near an airport, or b) near anything military? Wide band RF interference is very rare and you may need a guru, or talk to Ofcom ??

I am just over 13km immediately west from Doncaster Airport. Not aware of anything military that's still in use close by - but you never know I suppose. The flight paths used to push planes over our house years ago, however the flight paths got changed many years ago before the airport ramped up in demand. Very occasionally we do see a plane climbing from the front of the house. Airport (or at least it's estate) I think does still have some RAF presence.

Edited by gary333 (Tue 05-May-20 13:34:17)

Post deleted by gary333

Edited by gary333 (Tue 05-May-20 13:24:49)

I've given Ofcom spectrum helpline a ring for assistance. They have said unfortunately all the frequencies I have mentioned are unregulated, so they could not do anything.

I asked about devices they could recommend that might be able to help me track the cause down. They have advised something called an RSP1 or software defined radio to be able to start this process.

They mentioned it could well be anything power related (and they said they've had weird and wonderful), so as per one of the comments above I'm going to have to try wiring up the boiler and the router to a battery somehow if I want to work out if it's generated by me or external.

I'll give the cheapest option a whirl first, (the MW radio) and if nothing there looks like I need to dip in to my pocket and get some form of analyser.

Edited by gary333 (Tue 05-May-20 13:57:30)

D'oh!

Same applies to many modems/routers though. My Vigor 130 has a 12V DC input.

The size and shape of the antenna vary a lot, but tall vertical ones are often used - i'm talking about 40+ feet tall. The short 6 ft white ones are different frequencies which tend not to muck anything up apart from sometime remote car locking.
A good rule of thumb is if that it doesn't look normal, its some form of amateur radio, or other radio transmitter

The SDR they are talking about are the very cheap RTL tv dongles paired with some software such as sdr-sharp

Hi guys,

From a basic wifi analyser I can that there is a neighbours network with a single SSID but it is covering all 13 channels using 3 individual MAC addresses. The SSID is a Sky one and it looks like whoever this equipment is hasn't change the default name.

Is this normal for equipment to take up all channels, and what would be the reason for this? I can see the power level is quite high (nearly as high as my own router) and is present in the majority of the house. The scanner is showing many networks around, but this one stands out.

Keeping a log of the FTTC power levels too as I did get another drop to 2.4db between 7pm & 11pm Tuesday. However, this time you could see massive spikes on the TB quality monitor at the corresponding times.

In reply to a post by gary333:

From a basic wifi analyser I can that there is a neighbours network with a single SSID but it is covering all 13 channels using 3 individual MAC addresses. The SSID is a Sky one and it looks like whoever this equipment is hasn't change the default name.

That can happen with repeaters. You might find they have a Sky "boost" service so they have the main router near the Openreach socket, and boosters in other places. All transmitting the same SSID but on different channels. It is one of many reasons that 2.4 GHz is becoming "saturated".

However having a network SSID being broadcast doesn't mean you will have poor performance unless it is also being USED by devices (laptops, phones etc).

Can your scanner check the 5 GHz channels? Many of the free apps on Android can do both.

In reply to a post by jchamier:

In reply to a post by gary333:

From a basic wifi analyser I can that there is a neighbours network with a single SSID but it is covering all 13 channels using 3 individual MAC addresses. The SSID is a Sky one and it looks like whoever this equipment is hasn't change the default name.

That can happen with repeaters. You might find they have a Sky "boost" service so they have the main router near the Openreach socket, and boosters in other places. All transmitting the same SSID but on different channels. It is one of many reasons that 2.4 GHz is becoming "saturated".

However having a network SSID being broadcast doesn't mean you will have poor performance unless it is also being USED by devices (laptops, phones etc).

Can your scanner check the 5 GHz channels? Many of the free apps on Android can do both.

Unfortunately the only Android device I have is the kids rubbish Amazon Fire tablets and they don't have 5ghz.

Oh, I see with regards to the wifi mesh, i didn't realise they would take all 3 main 2.4ghz channels. Doesn't seem like a very good idea for anyone else other than the user.

NOTE: The mesh and channel occupancy might explain the wifi issues, solution shift your self to 5 GHz where possible.

It does explain issues with the other devices though i.e. 2.4 GHz will just affect 2.4 GHz unless there is a massive fault with the electronics driving the wireless devices.

In reply to a post by gary333:

Oh, I see with regards to the wifi mesh, i didn't realise they would take all 3 main 2.4ghz channels. Doesn't seem like a very good idea for anyone else other than the user.

It could be a mesh, but they usually self organise, and if your network was "quiet" (ie, not many devices transferring data) they could have used all of these channels. I suspect it actually just cheap repeaters, Sky have a service where they provide "boosters" which are repeaters. These are not normally self organising.

In the UK 2.4 GHz can be a problem, as our house density is higher than the US (outside cities !), so indoors you get high signal strengths from your neighbours. 5 GHz has less range so in many cases solves this problem.

there are some free/demo versions of WiFi scanners for Windows, e.g. the free app on the Windows 10 store:
https://www.microsoft.com/en-us/p/wifi-analyzer/9nbl...
If you are on Mac there is a (paid) app on the Mac App store which is very good.

Unfortunately iPhone has limited choice, the Apple Air Port Utility for iOS has a very crude ability to report, but it has no graphics, so it is very hard to interpret.

Edited by jchamier (Thu 07-May-20 14:00:16)

For Android, "Wifi Analyzer" is pretty good.

It also happens with Sky Q and a minibox operating as hotspots with Sky broadband because they operate on two channels in the 2.4GHz band. If the Sky hub is set to a 40MHz channel witdh it would cover the entire band.

In reply to a post by simon194:

It also happens with Sky Q and a minibox operating as hotspots with Sky broadband because they operate on two channels in the 2.4GHz band. If the Sky hub is set to a 40MHz channel witdh it would cover the entire band.

Good point, the minibox is working as a repeater.

Many 2.4 GHz access points offer the 40 MHz width as a way to increase throughput. This is useless if you have any Apple products in the home as they won't use any more than 20 MHz, in an attempt to help with the conflict.

Setting any 2.4 GHz access point to 40 MHz mode is "not neighbourly".

Last night I managed to catch the (edit* noise margin )reducing in real time (never seen this before, it's always either been 6.* db or 2.* db as I have no way to capture this from the device without logging in to the router admin page and watching.

What I found odd was at bang on 10pm the (edit* noise margin) started to reduce in 0.1db increments every 10 seconds until it made it's way down to 2.3db (from 6.2db) where it remained flat until after midnight. Not sure when it returned as went to sleep.

Is it usual to see a steady decline in level from local interference within house / neighbour or would you expect a sudden dip from the offending article?

I ordered a basic AM/FM radio from eBay and didn't realise it was coming from China so still waiting to perform the radio test. I've also replaced the Evohome with Tado.

Edited by gary333 (Mon 01-Jun-20 13:48:29)

In reply to a post by gary333:

What I found odd was at bang on 10pm the power started to reduce in 0.1db increments every 10 seconds until it made it's way down to 2.3db (from 6.2db) where it remained flat until after midnight. Not sure when it returned as went to sleep.

Did you mean power as thats not normally measured in decibels

In reply to a post by dect:

In reply to a post by gary333:

What I found odd was at bang on 10pm the power started to reduce in 0.1db increments every 10 seconds until it made it's way down to 2.3db (from 6.2db) where it remained flat until after midnight. Not sure when it returned as went to sleep.

Did you mean power as thats not normally measured in decibels

Power is usually labelled as dBm, decibel-milliwatts.

Almost certainly talking about the SNRM, as those figures are the same as posted in the OP for noise margin.

Whoops, yep, I meant the Noise Margin.

In reply to a post by j0hn83:

Power is usually labelled as dBm, decibel-milliwatts.

Thanks for explaining, helpful as always

I tried AM 612khz tonight in the car outside. I noticed a pulsing hum sound going up and down with the muffled sound of voices in the background. As soon as I pull off the drive and move 20m away I then start the get a foreign broadcast (possibly Spanish). The broadcast becomes very clear (well as far as AM ever is) and is present all around the village I live in. Whoever is broadcasting is speaking constantly.

The pulsing up and down sound is loudest (and the voices become very muffled and low volume) around my house.

As I pulled off my street in the car I heard beep, beep, beep (5 or more times). Sounded like the ones to announce the time or start of a broadcast.

Should I be getting a radio station on this frequency, as if so, how are you supposed to test for noise?

Cheers guys.

I would say that where the foreign station is clear, is good evidence of no local noise drowning the signal out.