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[andyfitter]

The attached screen shots show the performance of my line over the last two days. Initially the power line adaptors are in use, then for a period today I stopped using them, and then around 6pm this evening I started using them again as a test. 

Downstream significantly affected during the entire time the powerline is active.

Stats available as 'andyf' if anybody is interested.

[burakkucat]

Thank you for posting those plots. The effect caused by such devices does not surprise me . . . 

In attempting to "get the message" across, I always suggest that the frequency band used by such devices is compared with that of the xDSL service.

[broadstairs]

So why can't they be designed to use frequencies which do not interfere with xDSL ones?

Stuart

[roseway]

Probably because mains wiring is even more unsuitable for high frequencies than telephone cables.

[aesmith]

Mine make no difference whatsoever, not to noise margin, or errors or anything.  Maybe the interference is with the higher frequencies, so more of a problem for FTTC.

[GigabitEthernet]

Mine make no difference whatsoever, not to noise margin, or errors or anything.  Maybe the interference is with the higher frequencies, so more of a problem for FTTC.

I've found this - when I had ADSL I saw no effect at all but on FTTC they do impact it, although I find it depends how close the adaptors are to the router, so it's noise generated over the air rather than via the mains. But I need to do more investigation to confirm this to be the case.

[renluop]

I've found this - when I had ADSL I saw no effect at all but on FTTC they do impact it, although I find it depends how close the adaptors are to the router, so it's noise generated over the air rather than via the mains. But I need to do more investigation to confirm this to be the case.

Being still on ADSL, I don't get problems either, but I'm somewhat flummoxed by your mention of "noise generated over the air". How can that be? I didn't know other than that an Ethernet connection was needed between the router and the sending PLA.

Secondly what is near the router in feet, and are actually measuring direct or on Ethernet cable length?

I apologise for what may be is a naff post, knowing I'm not clever like many here!

[roseway]

When you use Powerline Adaptors the mains wiring is used to carry the DSL signals between the two (or more) points. The mains wiring is untwisted and unscreened, so it will radiate interference through the air as well as conducting it through the wiring.

[renluop]

Eric! I see, so the radiation is all around like the atmosphere, but then what has the distance PLA to router got to do with it?

[GigabitEthernet]

When you use Powerline Adaptors the mains wiring is used to carry the DSL signals between the two (or more) points. The mains wiring is untwisted and unscreened, so it will radiate interference through the air as well as conducting it through the wiring.

The units themselves also may well generate noise without going through the wiring at all - hence why the further away they are from the router, the less the effect may be seen.

[aesmith]

When you use Powerline Adaptors the mains wiring is used to carry the DSL signals between the two (or more) points. The mains wiring is untwisted and unscreened, so it will radiate interference through the air as well as conducting it through the wiring.

All powerline adapters that I've seen carry Ethernet rather than DSL, certainly that's what mine do.   What I haven't been able to find out on a quick check, is what frequencies it uses.

[roseway]

You're quite right of course, I worded my message badly.

[GigabitEthernet]

Some may well be better than others. I'm sure Tony said the BT ones he tried didn't create any noise he could see - which would make sense because BT should have done extensive testing.

[GigabitEthernet]

Can confirm the ones Tony suggested a while ago (BT 500s) cause CRCs on my line and a lot of FECs.

The only powerline adaptors that seem to cause little issue are some very old TP-LINK AV200 ones - shame they're quite slow and thus not really fast enough for FTTC.

I've ordered a mains conditioner to see if I can remove the noise that is being generated - I can't believe it's happening over the air because the powerline adaptors are not at all close to the router now (they are a good 50+ metres away).

[sevenlayermuddle]

May sound pedantic, but has to be pointed out...

Issues caused by powerline adapters will be a combination of...


The spurious emmisions radiated from wiring that carries the traffic.

And

The coupling between the mains wiring that radiates the emissions, and the wiring that feeds the modem. 

That coupling will be affected by various attributes of both the mains wiring and the phone line, proximity of these cables to one another, and relative signal strengths of the real vdsl signal vs the interference.  I'm not sure why proximity of modem to anything in particular should be a factor, but who knows - it might.

That being the case, I'm not at all surprised that by simply monitoring observed error rates, some people have 'evidence' of catastrophic damage, while others see no detriment whatsoever.   Too many variables.