In reply to a post by Ribble:

Repeaters arnt necessary or used for FTTx. The distances do not require it.
The GigE links from Cab to headend are good for around 40km or more and have no repeaters in the route.

But fibre only use light and light can only go so far before it fades

In reply to a post by WWWombat:

OK - forget all that stuff about fibre, ducting, blowing etc - it just doesn't apply to FTTC in any way that will *really* affect you.

Your cabinet (so long as you really do have one) will gain a twin "fibre cabinet" nearby (usually next to it, but certainly within 100 metres). The fibre will go to that cabinet, and could be routed anywhere - and might not even go back to your current exchange.

Your internet connection will then (still) be carried over copper, but only on the segment of copper from the cabinet to the house, plus a new segment of copper that goes between the original cabinet and its new twin. The connection is a variant of DSL called VDSL2.

I know about that bit, just wondered how it was laid really.

Spot on. If the distance is less than around 600 metres, then so much the better.

And that is the worry... FTTC can only be supplied if you have an existing cabinet. If there is no cabinet (ie you are on an exchange-direct line) then you won't be able to get FTTC.

You'd better try finding that cabinet

There is no way the cables here come straight from the exchange, we are to far away. I had a look on Google maps and found two cabinets close by, one i know about as i walk past it to work, the other i remember seeing, but i always thought it was too far away. It turns out going by Google maps, they are around 250-350 yards away from here, but Mr Bt man said there was a cabinet in a certain road and there is not, i had a walk and had a look on google maps and there is not one where he said.

As I said, I can't see myself going the fibre route to be honest, but my neighbour looks like that is what he wants to do. he does have a family so I can understand why he wants to go fibre. the problem is he is with Sky broadband and at the moment they don't seem to be bothering with fibre so he will have to change ISp. i think he is with Sky broadband,


we will wait and see, it could all go belly up and not be here until next year knowing BT.

it could all go belly up and not be here until next year knowing BT.

That also applies to me, you, and anyone.

Carpe diem.

In reply to a post by zyborg47:

But fibre only use light and light can only go so far before it fades

Don't knock light - it seems to be able to travel halfway across the universe and still be visible to the naked eye [1] .

Light itself doesn't really fade with distance; it simply gets spread-out (the inverse square law) and may be absorbed by the medium it passes through. You can think of fibre as "confining" the light so that it doesn't spread-out, but absorption still takes place over long distances.

As MHC and Ribble have indicated, the fibre runs used for FTTC are much too short to require amplifiers or repeaters. The fibre to my cabinet comes from a neighbouring exchange more than five miles away, and BT-OR managed to make it available within three weeks of the date they originally stated.

[1] http://www.nasa.gov/centers/goddard/news/topstory/20...

So of us are dependent on the BDUK lottery

I think many see fibre as new and unknown, reality is that BT has been using it for many many years. Just has always previously involved you spending £10,000 or so to get it installed and a few thous a month in rental.

In reply to a post by zyborg47:

In reply to a post by Ribble:

Repeaters arnt necessary or used for FTTx. The distances do not require it.
The GigE links from Cab to headend are good for around 40km or more and have no repeaters in the route.

But fibre only use light and light can only go so far before it fades

I suspect distance is not a problem for FTTC:

"The fourth generation of fiber-optic communication systems used optical amplification to reduce the need for repeaters and wavelength-division multiplexing to increase data capacity. These two improvements caused a revolution that resulted in the doubling of system capacity every 6 months starting in 1992 until a bit rate of 10 Tb/s was reached by 2001. In 2006 a bit-rate of 14 Tbit/s was reached over a single 160 km line using optical amplifiers"

http://en.wikipedia.org/wiki/Fiber-optic_communication

and

"The current laboratory fiber optic data rate record, held by Bell Labs in Villarceaux, France, is multiplexing 155 channels, each carrying 100 Gbit/s over a 7000 km fiber"

http://en.wikipedia.org/wiki/Optical_fiber

Edited by Andrue (Thu 26-Jan-12 08:27:32)

In reply to a post by MrSaffron:

I think many see fibre as new and unknown, reality is that BT has been using it for many many years. Just has always previously involved you spending £10,000 or so to get it installed and a few thous a month in rental.

I'm curious to know whether FTTC changes anything for anyone who wants FTTP; is there any capacity within the FTTC fibre infrastructure to provide FTTP for those prepared to pay, albeit at a much lower cost than the kind of the numbers you mention, but probably more than in the handful of areas where FTTP has been rolled-out?

In reply to a post by MrSaffron:

I think many see fibre as new and unknown, reality is that BT has been using it for many many years. Just has always previously involved you spending £10,000 or so to get it installed and a few thous a month in rental.

One of my first design projects used fibre ... that was on a Cross Channel link. The year ... about 1980 ish.

In reply to a post by MrSaffron:

So of us are dependent on the BDUK lottery

[Chuckle]
(/me passes Andrew the right end of the stick).

I was talking about the mortality lottery .