Would Fibre Roll Out impact ADSL Speeds?

FTTC is currently being deployed from my local exchange (Heckington - EMHECKI) as part of the OnLincolnshire project. Being out in the sticks, I'm on the end of a relatively long line (c.3Km) but have been able to maintain a pretty stable sync speed of about 8.5Mbps which equates to a throughput of about 7.5Mbps. This is supported by data from the SamKnows monitor I have on my line which has shown a pretty stable average of 7.5Mbps since the start of this year.

In the last month (since the work started on the upgrade) I've seen a significant drop in overall throughput of about 40% so 7.5Mbps has become about 5Mbps and sometimes less than 4Mbps. I contacted my ISP who advised that some noise had been detected and that a restriction had been put on the line. That would be lifted and the line should return to normal. However, in the two weeks since, the sync speed hasn't risen above 6Mbps. Current stats are as follows:

Downstream
Connection Speed: 6073 kbps
Line Attenuation: 41.0 db
Noise Margin: 9.6 db

Upstream
Connection Speed: 1108 kbps
Line Attenuation: 21.9 db
Noise Margin: 6.5 db

I also note from the OnLincolnshire Project Website that the Cabinet that my line is connected to (Cabinet 2) was upgraded as of Friday 3rd October.

Is it possible that the FTTC upgrade work has somehow impacted the quality of my line and if so, is there anything that I can do about it? Would the increased noise on the line would also impact any speed improvement I might see if I were to upgrade to FTTC? The BT Wholesale checker reckons I might get 8Mbps on FTTC but that's not going to be much of an improvement if I can get back to the 7.5Mbps that I previously got before the upgrade work started.

No more impact than the usual engineer working in a cabinet might affect another line scenario

The 9db noise margin explains drop in speed normally would be 6dB

There have been a number of posts here where Adsl speeds have reduced and coincidently Fibre has recently become live.

So it's possible that the work has impacted my line. Is there anything I can do about it?

If anything, my own ADSL2+ connection speed has improved. Fibre may be reducing interference in ADSL2+ lines, since fibre doesn't produce any interference between the cabinet and the exchange.

Both our connections have had their cabs wired ready for fibre switch om in the last few weeks. Enta in Suffolk and the dreaded EE in Hamilton.
Service on both has been all over the place with several disconnections. Coincidentally. both copper lines are now running a lot faster, which I can only put down previous bad joints/connections being worked on. So I would say fibre installation definitely effects a copper service.

The messing around seems to have caused a short-term fault. Assuming there are no ongoing noise problems that 9.6dB noise margin should reduce to 6dB within 10-14 days of it being set, and with luck to 3dB 10-14 days after that. To get to over 8Mbps sync I would think the noise margin was 3dB.

Each drop will cause an automatic re-sync at a considerably higher speed.

Until the first one doesn't occur very few ISPs will want to take any action on something the system is designed to handle itself.

Keep us posted, so we can advise further if the first one occurs. Or doesn't!

Edited by RobertoS (Sat 04-Oct-14 21:40:54)

I know BT set ADSL/ADSL2 SNR target at 6dB default. But, what about FTTC SNR target default set by BT?

Edited by adslmax (Sun 05-Oct-14 16:08:35)

Back down south today, only to find plenty of messing around on my Freeola Enta service. Lets hope it's down to blowing the fibre, but been ongoing for some tome now.
http://www.thinkbroadband.com/ping/share/9c0ab536e12...