Street lights interfering with my broadband

cram1971

I am not 100% sure of this but I think one of the street lights is causing interference with my broadband. I have been having issues from dusk till dawn with poor Noise margins. It drops from 13db to about 6.8db at night. It seems to be getting later and earlier as the days get longer. Anyone else have this problem and how did they sort it out?

advertsfox

cram1971 wrote: »

I am not 100% sure of this but I think one of the street lights is causing interference with my broadband. I have been having issues from dusk till dawn with poor Noise margins. It drops from 13db to about 6.8db at night. It seems to be getting later and earlier as the days get longer. Anyone else have this problem and how did they sort it out?

Night time issues are generally because more items in the household are in use that could caused a performance decrease due to electronic inference (landlines, Sky boxes etc) but that's only a possibility.

How many phone points do you have in your house?
Where in the house is the broadband connected?
Is the broadband connected through a DSL filter?
How many phones do you use in your house?
Do you have Sky connected to the phone?
Do you have a monitored house alarm?

Can you also post your full line statistics too please and tell us what speed you are subscribed to as well.

cram1971

Thanks for the quick reply. To eliminate all internal issues I have connected my phone line directly to my router directly with no filter for one week and recorded the DSL line noise using router stats lite. I have also powered everything off in my house except the router (at the fuse board) to eliminate anything internally there was a.5 db decrease in noise. The line attenuation is 58db and remains at that all the time.

cram1971

Sorry my I am on Eircom ngb on at the moment I am on a 3mb profile which I get full speed during the day and it drops back to 2mb in the evening when he line noise gets bad.

advertsfox

cram1971 wrote: »

Sorry my I am on Eircom ngb on at the moment I am on a 3mb profile which I get full speed during the day and it drops back to 2mb in the evening when he line noise gets bad.

OK well the problem is your line is trying to keep up with a 3MB profile but with a 58dB attenuation you will only ever obtain a stable 2MB. Ring your provider and ask them to drop your profile to 2MB RH (High interleaving - error checking enabled to improve stability) and test it again, this should sort the issue. I imagine your sync will be a solid 2048/256 kbps with a noise margin of about 12-15dB (a line will be problematic it your noise margin is less than 11dB).

Alternatively, you have ask Eircom to make sure interleaving is enabled now on the 3MB profile (which it is by default) but since its good during the day and poor at night, I would bet it is already. I would suggest a stable 2MB so the line doesn't have to work as hard.

cram1971

My line is quite stable during the day time at 3mb and I was hoping to get to the root of the problem to get a 3mb connection at night. I don't particularly want to loose my connection speed. Can't wait for FTTC to arrive in my area should be by end of year.

advertsfox

cram1971 wrote: »

My line is quite stable during the day time at 3mb and I was hoping to get to the root of the problem to get a 3mb connection at night. I don't particularly want to loose my connection speed. Can't wait for FTTC to arrive in my area should be by end of year.

Not going to solve much I'm afraid, your noise margin is the issue so unless you can switch to an LLU service, you won't achieve constant 3Mb speeds. At night, the area will start using their broadband and it will affect the line to your house - generally this wouldn't be a problem for a normal stable line but your nearly 6KM from your local exchange. Enquire about the interleaving and make sure high is enabled (as opposed to low or off).

PS: Test 2Mb for a few days, you'll see a vast difference esp. with latency and line statistics / errors).

cram1971

Thanks a million for your replies., how would llu make a difference. Would I not just be just getting my broadband from a different provider over eircoms infrastructure ?

Sponge Bob

UPC are currently recalling a load of their modem power supplies owing to the interference they cause. I would think that if it is a streetlight then.

1. The overhead portion of your line will be affected, not the underground. Is there a flickering start stop light near it??

2. Easier to prove in the morning, eg a jump in speed and a reduction in the noise level in DB in your line stats between all lights on and all lights off c 7:30 am.

3. If you do find a suspicious light around lights off at say 7:30am ish in the morning report it to the ESB who normally have a contract to fix street light issues. It could also be a night security light in a yard.

Yes it is possible.

cram1971

Sponge Bob wrote: »

UPC are currently recalling a load of their modem power supplies owing to the interference they cause. I would think that if it is a streetlight then.

1. The overhead portion of your line will be affected, not the underground. Is there a flickering start stop light near it??

2. Easier to prove in the morning, eg a jump in speed and a reduction in the noise level in DB in your line stats between all lights on and all lights off c 7:30 am.

3. If you do find a suspicious light around lights off at say 7:30am ish in the morning report it to the ESB who normally have a contract to fix street light issues. It could also be a night security light in a yard.

Yes it is possible.

When I had Eircom out they told me about the UPC problem but there is no UPC in my area. The funny thing is the interference gets worse over about 20 minutes at night but get better instantly in the morning, i think the over ground portion of my phone line is only a couple of hundred meters.


I was hoping some one would say something like take a mw radio and tune it to xxx and walk down the road.

Sponge Bob

Sponge Bob wrote: »

3. If you do find a suspicious light around lights off at say 7:30am ish in the morning report it to the ESB who normally have a contract to fix street light issues. It could also be a night security light in a yard.

I believe it's Airtricity who are responsible for maintenance of street lighting now.

arctan

cram1971 wrote: »

When I had Eircom out they told me about the UPC problem but there is no UPC in my area. The funny thing is the interference gets worse over about 20 minutes at night but get better instantly in the morning, i think the over ground portion of my phone line is only a couple of hundred meters.


I was hoping some one would say something like take a mw radio and tune it to xxx and walk down the road.

take it out and scan around the MW/SW band and see, not all interference has a set frequency (DSl will be from 25KHz to 1.1 MHz so scan through that)

I'd be inclined to think the light is the issue if you've noticed the pattern and the 20min period would coincide with the light circuit heating up to maximum temperature

although, numerous other sources will do the same, grab the radio and start walking and see.

Sponge Bob

I have heard all sorts of EMI stories involving a Neon Light in a chipper that took out the HF bands to a well known Boardsie whose neighbours Samsung TV took out the entire FM band ...and it took Comreg ages to do anything about it.

Comreg were very fast off the mark when the UPC modem power supply issue was proven last year, probably because it was detectable in Dublin.

arctan

think it was more that eircom's business was being hindered in a lot of areas this was effecting and they threatened legal action...

it's actually ridiculous how many customers one bogey power supply can knock out or affect.

Alun

I had a similar problem a couple of years back too. The MW radio trick worked to establish that it was in fact some kind of RF interference, but I couldn't localize it sufficiently. Got Comreg involved and they managed to pin it down to one of my neighbours, but I never found out exactly what equipment it was that caused the interference.

lucernarian

advertsfox wrote: »

OK well the problem is your line is trying to keep up with a 3MB profile but with a 58dB attenuation you will only ever obtain a stable 2MB. Ring your provider and ask them to drop your profile to 2MB RH (High interleaving - error checking enabled to improve stability) and test it again, this should sort the issue. I imagine your sync will be a solid 2048/256 kbps with a noise margin of about 12-15dB (a line will be problematic it your noise margin is less than 11dB).

Alternatively, you have ask Eircom to make sure interleaving is enabled now on the 3MB profile (which it is by default) but since its good during the day and poor at night, I would bet it is already. I would suggest a stable 2MB so the line doesn't have to work as hard.

I've have to disagree with much of this. Most DSL connections can happily function on 6dB signal margin if there are no substantial problems with intermittent but strong electromagnetic interference. That's why it's called signal margin. It's the current signal level above the minimum signal level needed to establish a connection over any noise on the line. It's related to signal-to-noise ratio but not the same thing.

Suggesting that the customer reduce their speed by 33% is madness, considering there's been no disconnects reported! IF the modem is able to handle the reduced speed without disruption, there's no point in enforcing a lower speed on the line.

The attenuation on this line is high but it may not be so crucial here. My own family's line is capable of 3.5mbps with 55dB attenuation and no instability whatsoever. Albeit on ADSL2. Any line is able for whatever speed it can get, until the signal margin reaches 6dB typically. Whether the attenuation is 40dB or 60dB, signal margin is all that really matters.

I don't see how you can tell the connection is interleaved or not, purely by how fast it is during the day vs night. Only real way to tell that is to run a ping test to some server in ireland, like www.rte.ie or www.boards.ie. That'll indicate the level of interleaving.

Also, having interleaving turned up does have the side effect of increasing ping times to ~55ms for Irish servers. Thought I'd mention this if the OP happens to play a lot of online games.



@Sponge Bob, the fact a line is over or underground makes sweet f all difference. At the frequencies of DSL, 2 feet of clay and stones will barely stop any radio interference affecting phone lines.

Sponge Bob

To_be_confirmed wrote: »

@Sponge Bob, the fact a line is over or underground makes sweet f all difference. At the frequencies of DSL, 2 feet of clay and stones will barely stop any radio interference affecting phone lines.

Point taken but the old non directional finding listen to the MW radio trick is hardly any better in many cases either.

EMI is hard to localise and out of office hours EMI is a bitch.

It will be much worse with CDSL which relies on even more blear frequencies to work. The UPC issue afected the primary synch frequenices from what I remember, not a DMT here and there.