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[xreyuk]

Hi Guys,

I've installed a power line adapter in a socket near my router. The power socket is about 1.5 - 2feet away from the ADSL socket, and a couple of feet from the modem.

I've been messing around over the past few days which has meant the power has gone on and off a couple of times. I noticed that after the first power on (and just after installing the power line adapter) that the line errors increased massively.

I don't know if it's the power off and on of the HG612 modem has possibly borked it, or whether the errors are caused by interference from the power line adapter.

DLM has increased by delay and INP, but again, not sure if this is because of interference or 3 power offs in two days.

Any ideas?

[JGO]

YES - they can, and not just to BB !

Off the cuff, suggest as you are deliberately putting potential interference into the 50Hz, so power filter is essential for the modem and quite possibly usual  radiation interference precautions i.e. filtered faceplate, and ( RF3 if it is a Mk1 so not included in the facepate).

[NewtronStar]

Hi xreyuk yes powerline adapters caused a lot of interference with my HG612 on VDSL2 it was that bad I've gone back to wireless adapters.

If you have dslstats installed the tell tale signs for me was the massive FEC errors at 200,000 - 600,000 per minute once the powerline adapters were taken offline they fell back to 250 - 1000 per minute.

[broadstairs]

Just to say that these adapter CAN cause interference but in my experience they do not ALWAYS cause it. Mine for example do not, I suspect it has quite a lot to do with other things not just the adapters. I have tested without mine and have seen no difference in the level of errors on my line.

I would always say that running cat5 or 6 cable is preferable if possible but dont go away with the idea that the powerline adapters cannot work.

Stuart

[JGO]

Broadstairs, I think the point is that as these adapters are sold for use with BB it could reasonably be assumed by a beginner that they don't interfere with it at all.

 This is not so, on N.S's evidence alone,  but in your case I wonder if existing anti-interference measures see it off ? I know of another adapter installation where this seems to be so.   

Obviously FFTC will be more susceptible than ADSL2+ which is in turn more susceptible than ADSL1 so there isn't a 1 bit answer !   

[xreyuk]

Thanks.

I'm running a test now, I've had the power line adapter disconnected for the past 22 hours and have made a note of errors on my line. I'm going to put it back tonight and see if it causes any increase in errors tomorrow evening.

[JGO]

Sounds good !  but suspect you get more interference when the link is working hard than idling - can you download "Gone With The Wind " ? !!!!! 

[rob]

It can greatly depend on the powerline adaptors you use as to whether any noticeable interference is seen.  For example, I've been using a pair of D-Link AV200 (DHP-306AVs) to bridge upstairs with downstairs for many years and these don't cause any additional interference in my home (my error rate remains pretty constant with or without them connected at ~300 CRC errors per hour).  Whilst they're not the fastest units, at the time they were much easier than running in network cable and have proved much more reliable than wireless.

More recently I attempted to replace them with the AV500 units from Zyxel.  After a few hours of them being connected I'd seen that my line had become interleaved, lost several Mb of downstream speed and was showing many millions of FEC errors every 15 minutes.  Whether the homeplugs were in use or not was irrelevant - the interference was there to see regardless.  Disconnecting them, the line stats returned to sensible values, so I swapped my original AV200 adapters back in.  Until interleaving was removed from my line, which took about 2 months, the modem was reporting about 10,000 FEC errors every 15 minutes.

I don't know if the interference was caused by the higher bandwidth signalling in the AV500 specification or by poor noise suppression in the adapters.  Other brands of AV500 units may fair differently but I'm planning to eventually replace my AV200 adapters with network cable as and when I get time.

[xreyuk]

I ended up having to download a large file last night, which means there was a lot more activity in this 24 hours than the previous 24 hours.

I'm going to give it another quiet 24 hours (like the other day) and see what the error rates are like.

The error rates have increased from 0.64 ES per hour to 1070 ES per hour. And the RsCorr % has increased from 0.04% to 12.4%. CRCs have increased from 4.23 per hour to 3698 per hour, HEC's from 58.6 per hour to 687 per hour, and FECs from 46834 per hour to 21746410 per hour (I have an interleaving depth of 2395 since DLM started kicking in)

Are those error rates high? could those increases been just down to increasing activity on the line?

Thanks.

[NewtronStar]

The error rates have increased from 0.64 ES per hour to 1070 ES per hour. And the RsCorr % has increased from 0.04% to 12.4%. CRCs have increased from 4.23 per hour to 3698 per hour, HEC's from 58.6 per hour to 687 per hour, and FECs from 46834 per hour to 21746410 per hour (I have an interleaving depth of 2395 since DLM started kicking in)

I take it the above results are when you re-connected the powerline adapters ? if so it's going to take upto two weeks for your line stats to recover, the DS Sync will recover first say 4-5 days and interleaving depth takes longer thats why I say two weeks, as long as you stop using the powerline adapters.

[xreyuk]

That's correct, I've got rid of them, and the 24 hours without them the errors were much better, so I definitely think they were causing an issue.

Unfortunately DLM has decided to put me on a 35Mbps banded profile. My SNRM is now a massive 9.6dB, although my interleaving has been reduced. I"m assuming I just have to wait for this to sort itself out?

[NewtronStar]

I"m assuming I just have to wait for this to sort itself out?

I am afraid so 

[xreyuk]

Well it took me off the banded profile this morning, which I thought was rather quick, but I now have another problem.

I use the --maxDataRate command to configure a max downstream rate of 38700Kbps, as I'm trying to see whether this would reduce my interleaving. Before seeing this interference, I would have an SNRM of around 7.9dB with this speed, and a 6.2dB SNRM when connected at ~43000Kbps.

I've resynched this morning at 38696Kbps, but only have an SNRM of 6.6dB which is much lower than it was before. I noticed that my max attainable dropped by about 800Kbps. The pbParams shows all the same line attenuations as before this problem.

Is there anything I can do to find out why I have a poor SNRM?

Cheers

[xreyuk]

Anyone?

[les-70]

  Without details it is hard to say but from what you describe the cause may well just be more cross-talk with your line i.e. some else now has FTTC.  If so I am afraid that you probably just have to accept it.