Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: rp00 on October 05, 2016, 10:24:13 AM

Title: Homeplugs and VDSL (with graphs!)
Post by: rp00 on October 05, 2016, 10:24:13 AM: Hi There
Over the last few months, my sync speed dropped from high 60Mbps to low 40Mbps.
I was told by my provider this is caused mainly by an interference (somewhere on my side of the line).
I've traced it down to my set of homeplugs!
FECS dropped significantly (on a bad day FECS15 was between 1000k-2000k, 100k-500k was the norm), now is barely a few thousands .
I can only hope DLM will recover from it:)

Graphs attached
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: raislander on October 05, 2016, 11:37:48 AM: This is a fact. I posted something yesterday as I was going nuts with my new BT Infinity. I couldn't imagine why when I was using the line (DL) the number of errors would start to peak up, and the line would become unstable.

I did some testing yesterday after reading a paper work (study case), that PLC and VDSL2 share the same frequencies. Turns out it's spot on. If your homeplugs (PLCs) are less than 1m far from your DSL modem/plate then the noise (which affects the same 0.2-17MHz range) will affect your speed and SNRM.

I have moved the PLCs through a cable to the other side of the room, while keeping it 1Gbps speed all through and now, no noise....line is up from 50M synch to 62M synch which is the max my line can achieve. I just need a bit of patience to get the DLM to stop and put G.Inp back in place and it will all be good.

Definitely this should be informed by the HomePlug vendors as it can create so many issues without even noticing where this came from.
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: broadstairs on October 05, 2016, 11:58:19 AM: Is that case study available online somewhere please?

Stuart
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: raislander on October 05, 2016, 12:07:11 PM: You've got the document attached. If you want to get some more info, google: "PLC VDSL2 coupling" there are several links to the same study case.

This is something that vendors should be aware of or at least give you some notice on their manuals when you purchase the Home Plugs and you've got a VDSL2 line.
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: raislander on October 05, 2016, 04:43:54 PM: This is what happens in my case with the line. The "GAP" occurs whenever I start to download from a computer that is behind the PLCs. If I remove the PLCs the line has a consistent SNRM of 6.1dB, no matter where I download from (WIFI or cable). It's the PLCs what introduces the noise. I've tested with the TP-link 1200 and the Devolo AV 500, same results, so the Home Plugs generate noise in the line.

This PLCs are now 2m away from the socket, and I lose 1dB when the problem occurs. Before I lost almost 2dB.
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: NewtronStar on October 05, 2016, 04:59:22 PM: I was under the impression the PLA's induce noise onto the electrical home wiring so no matter how far those PLA'a are from the modem the noise will get in via any electrical socket to the hardware and causes an RFI loop :-\
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: raislander on October 05, 2016, 05:23:33 PM: Precisely. So either you remove the Home Plugs or you leave with the fact that your VDSL2 line performance is going to be reduced because of the presence of those devices at your home.

I can't put CAT6 all around the property, so I may need to keep going with the current solution, not ideal, but at least I know how I can mitigate the issue.
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: burakkucat on October 06, 2016, 09:31:21 PM: Quote from: broadstairs on October 05, 2016, 11:58:19 AM
Is that case study available online somewhere please?

The URL for that paper is http://www.ursi.org/proceedings/procga11/ursi/E07-3.pdf
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: Weaver on October 08, 2016, 12:35:30 AM: Why not go 5GHz WLAN instead? With intermediate wireless LAN relays as needed? I know what an utter pain it is running network cable around place. I just wish I had put ducting in when I did my small house up thirteen years ago.

Rant: I do absolutely hate homeplugs like poison and think they should be banned if there is any chance at all of them infecting the neighbours, either through the mains or directly by radiation. I can't understand why they were ever allowed unlicensed.
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: Alex Atkin UK on October 18, 2016, 01:10:31 AM: I was absolutely shocked to see Sky decide to build-in Homeplugs into the SkyQ box and their new VDSL router.

I wonder if they added some complicated filter in their router to avoid these issues? Or are they just utter morons?
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: Weaver on October 18, 2016, 04:05:18 AM: Idiots, what about all the disruption to other kit? Should simply be banned.
Title: Re: Homeplugs and VDSL (with graphs!)
Post by: j0hn on October 18, 2016, 05:42:40 AM: I recall a number of threads where users have had problems with homeplugs, but switching the brand/model has made the problem go away. Perhaps Sky have used the least intrusive version of the technology. If it does effect the xDSL performance then it should certainly come with some clear literature warning about the proximity of power sockets/electrical wiring to the master socket/incoming BT feed.

edit: here (http://forum.kitz.co.uk/index.php/topic,14463.msg270758.html#msg270758) & here (http://forum.kitz.co.uk/index.php/topic,16748.msg311294.html#msg311294)