Infinity - An engineers report.

If anyone remembers my last post I recently had FTTC installed with BT. While all tests confirmed I could recieve approx 24 Mps /5Mps, I only saw a speed of 8.0 / 0.9 Mps. Old ADSL was acheiving 6.0 / 0.4 Mps. My ten day settling period had expired so I was finally able to have an engineer out. He was quite suprised I was even getting the speeds I am. According to him BT have experienced frustrating "real world" drops in FTTC speeds over distance. I am 1.8miles for my FTTC cabinet and apparently 3 miles from the exchange. Yet note the only small improvement FTTC brings. He, as did the first engineer who installed in the first instance, said that over 1.5- 1-7miles from the FTTC cabinet and they've seen unusable speeds or speeds slower than the customers original ADSL. 'He claimed' ..BT are a bit alarmed by this as FTTC promised speeds have not been realised in the real world. I questioned him quite a bit about it as I was interested in the concept of FTTC speeds dropping faster over a shorter copper line than ADSL over longer pure copper line? I queried if it was perhaps an error in the way my FTTC and copper line are joined, but he dissmissed this stating that BT are aware of the substantial drops being seen and there are meetings between bosses to try and find a solution to the problem. Any thoughts guys?

The higher frequencies used for VDSL will attenuate more per km than the lower ones of ADSL2+ which in turn attenuate faster than the base level ADSL. Having said that you only lose what you didn't have in the first place so in general you won't do worse on a "better" standard as your results show.

>2km is beyond the typically envisaged VDSL range so there isn't a whole lot of data around. It would be interesting to see line statistics especially a 300 kHz or similar attenuation figure to understand if the line loss is consistent with its length or in some way higher.

The engineer said BT were trying to find a solution to work around the problem (Fingers crossed but not holding my breath.) What about a modulator between the FTTC and my copper that varies the frequency to give a maximum achievable speed? Or is this already being done at the cabinet?

The engineers that you get attending to you will have nothing to do with any solution, that will come from the central test labs.

As for the speed drop off, basic physics tells us that will be the case, and projections like http://www.thinkbroadband.com/guide/fibre-broadband.... have been possible for years. Certainly since Openreach was working on the VDSL2 deployment in the UK. (That chart is based on data from the original paperwork). 1600m is around 1m, so if you are 1.8m then your speeds are not a surprise at all to me.

As for the solution - there is no need for Openreach to provide fast speeds to everyone. In 2013 you will have the choice of paying for a full fibre install if speed is important to you, but not cheap.

regenerators are coming for ADSL services in some parts of the UK, but unlikely to appear for VDSL circuits. What you can do is bond two VDSL circuits to improve performance.