Rural deployments by OR

How do OR handle sparse rural deployments where you have properties spread out along rural back roads with no real cluster?

Ive seen the CBTs on poles but these i assume are run out from some other splitter rather than right back to the AG node.

From a non UK installer they're talking about 1:2 splitters to Tap off the fibre to properties as theyre passed but this would either require a very accurate survey and bespoke lengths ordering or an awful lot of fibre splicing.

For example my road has 17 or so houses along the route, all old farms with driveways approx 500 to 700 metres apart .

Gary

Openreach GPON split is 32

Usually 1 manifold and 1 splitter and the agg node, various lengths of pre-made connectorised fibre are available, and the manifolds come in various port sizes

So in terms of accurate length, the survey for the manifold install needs to be reasonably accurate but plenty of scope for handling a few metres of wrong measurement.

I think the question is: if you have one splitter, then 17 properties in a straight line each 500 metres apart, how would it be pre-cabled?

For example: would there be 17 separate CBTs, each one with a separate cable back to the splitter? Or something else?

Yes, exactly that.

The CBT is basically a dead end, yes ? It would serve very few properties, Theres no passthrough. final drop connections to a CBT are relatively short range arent they ?

So either you run multiple CBT each with increasing length back to the splitter or you have to have multiple splitters spaced along the route each feeding the next set of CBTs, And if thats the case is the fibre daisy chained from one splitter to the next with usable strands reducing each time or would each splitter run back to the AG.

Openreach can still blow fibre to properties where necessary, so for properties in rural areas which might be 100s of metres away from the final DP/node, they may decide to blow fibre rather than use connectorised cabling. AFAIK the max length of connectorised cable is 160m though it can go up to 300-400m in special cases.

There are quite a few rural deployments in Wales ( and Cornwall) that meet this criteria.

There maybe someone from these areas that can answer your question.

I suspect from some I have seen that each CBT may only serve 1 or 2 properties and there will be many CBTs to each splitter.

Nah, there�s 360m kits, on special order.

And if you need a CBT right out in the sticks , then you run track node to track node.

In reply to a post by Zarjaz:

Nah, there�s 360m kits, on special order.

And if you need a CBT right out in the sticks , then you run track node to track node.

I agree

The only thing I am surprised with is that the smallest CBT is 4 port, I think there would be good reason to have 1 and 2 port CBT's for more isolated deployments where 4 ports is overkill.

Edited by deleted (Thu 05-Sep-19 22:29:55)

Okies, thanks all.

Just trying to properly understand what the current way of doing the 'proper' rural runs is.

There's three houses fed by copper off the pole on the B road that we live off, one close maybe 75m, but ours is 620m from that pole all on overhead, similar length as the 3rd but in the opposite direction.

In reply to a post by Swac3:

There's three houses fed by copper off the pole on the B road that we live off, one close maybe 75m, but ours is 620m from that pole all on overhead, similar length as the 3rd but in the opposite direction.

So how does the copper currently get from that pole to your property? is it via further poles or ducting or buried directly in the ground?

Edit: I have reread your post again and if their are further poles your CBT could be fitted on a pole nearer to you if the max length of a connectorised fibre cables is reached, I also believe I have read on here where someones installation they spliced two connectorised cables together (cutting the second connector off) to extend the reach. but not every installation is the same.

Edited by deleted (Fri 06-Sep-19 08:52:48)

What's a "track node"?

A �through� joint. Or where a joint where the feed splits a couple of ways.

In reply to a post by Zarjaz:

A �through� joint. Or where a joint where the feed splits a couple of ways.

Just to add to that there is no splitting of a single fibre, all fibres are a one to one connection, but a bunch of fibres can be split a couple of ways.

Edited by deleted (Fri 06-Sep-19 09:25:26)

Thanks. So in what circumstances would Openreach blow fibre to a property instead of using connectorized cables? Or have they completely scrapped blown fibre now for the last leg? I'm well aware that its mostly connectorized installs these days, however I thought blown fibre was still an option for Openreach.

Edited by deleted (Fri 06-Sep-19 09:52:02)

Not strictly accurate. In a GPON scenario you can run down a lane with a single fibre and at the bottom of the every drive install a splitter for a branch for each house. Openreach may choose not to do that (which would be bizarre as it is one of the selling points of a PON architecture over a PtP one) but it does not mean it is not possible.

Presumably if you have a drive longer than 340m. In a rural scenario that would be quite common.

Edited by jabuzzard (Fri 06-Sep-19 16:45:04)

In reply to a post by jabuzzard:

Not strictly accurate. In a GPON scenario you can run down a lane with a single fibre and at the bottom of the every drive install a splitter for a branch for each house. Openreach may choose not to do that (which would be bizarre as it is one of the selling points of a PON architecture over a PtP one) but it does not mean it is not possible.

I was explaining how a track joint is used not anything about infrastructure design in that post.

In reply to a post by jabuzzard:

In a rural scenario I would that would be quite common.

Interesting comment.

They�ll blow from a manifold that�s existing .... in some locations there�s manifolds AND CBT�s on the same DP.

In reply to a post by Zarjaz:

They�ll blow from a manifold that�s existing .... in some locations there�s manifolds AND CBT�s on the same DP.

Ah ok, wasn't aware that blown fibre could co-exist with the newer connectorized stuff at the same node/DP. You learn something new everyday

In reply to a post by baby_frogmella:

In reply to a post by Zarjaz:

They�ll blow from a manifold that�s existing .... in some locations there�s manifolds AND CBT�s on the same DP.

Ah ok, wasn't aware that blown fibre could co-exist with the newer connectorized stuff at the same node/DP. You learn something new everyday

No reason why not. It�s not like it�s connectorised all the way back to the exchange.

In reply to a post by jabuzzard:

you can run down a lane with a single fibre and at the bottom of the every drive install a splitter for a branch for each house. Openreach may choose not to do that

As you say Openreach may choose not to do that but that's their choice just like its other providers choice how they design their infrastructure. There are documents online that show Openreach were planning on adding a second level of splitting built in to their CBT's but what I understand from the experts on this forum its not how its done today.

In reply to a post by jabuzzard:

Not strictly accurate. In a GPON scenario you can run down a lane with a single fibre and at the bottom of the every drive install a splitter for a branch for each house.

I don't think it's useful to daisy-chain splitters in the way you describe.

Even a 2:1 splitter has a theoretical minimum 3dB optical loss (half the light down each leg), more like 4dB in practice. Once you've daisy-chained five splitters, in theory the loss is the same as a 32-way splitter, but in practice is significantly higher. It's not going to be great for reliability either.

Yes more poles to the house,, The OR copper runs along the road popping up somewhere close 'ish' to either a run of poles up the farm tracks to each property or for some that are closer to the road you cant see poles so must be buried.

Very similar to the segment 2 rural figure in Cartesians full fibre cost modelling report

It's a massive problem across a huge area up here moray/ Aberdeenshire. These places were traditionally tenant farms approx 70 to 100 acres each and while now most of the land is farmed by much bigger holders the old farmhouses are residential.

In reply to a post by candlerb:

In reply to a post by jabuzzard:

Not strictly accurate. In a GPON scenario you can run down a lane with a single fibre and at the bottom of the every drive install a splitter for a branch for each house.

I don't think it's useful to daisy-chain splitters in the way you describe.

Even a 2:1 splitter has a theoretical minimum 3dB optical loss (half the light down each leg), more like 4dB in practice. Once you've daisy-chained five splitters, in theory the loss is the same as a 32-way splitter, but in practice is significantly higher. It's not going to be great for reliability either.

Bzzt, wrong answer. While not common you can get unequal power splitters for just this scenario. It is notionally one of the benefits of the GPON system that you can do deployments like this and keep costs down. That is it has been thought about when devising the standard.

Whether Openreach use unequal power splitters is an entirely different matter, however it is technically possible.

In reply to a post by jabuzzard:

Whether Openreach use unequal power splitters is an entirely different matter, however it is technically possible.

I have no idea about unequal power splitters but I do know there are lots of things that may be possible in the world we live in but it doesn't always make them practical/sensible for large implementations.