FTTH vs FTTHoD

Is one better/preferred to the other?

And as well how does FTTHoD work I know you have to have FTTC in your area but FTTHoD doesn't use the cabinet and people tell me that it uses a aggregation node near it but I thought the aggregation node was near the exchange?

(This is FTTH) Exchange, Aggregation node, primary splitter, secondary splitter then fibre to your home

Can you do a similar thing to this but with the cycle of FTTHoD

Edited by bluluke (Sat 25-May-13 01:17:01)

They are exactly the same apart from that one is built proactively and the other, well, on demand.

Yes, FTTP/H is preferred because BT pay

They are physically identical. The differences are in where it can be ordered (which are mutually exclusive, so you never have a choice), who pays for the bulk of the installation work, and the choice of products that can be ordered over the top.

Right now, we don't really know where the aggregation nodes are. Some of the architecture diagrams make it look like one exists near the exchange, while the distance estimates in PR for FTTPoD make it seem like Aggregation Nodes are not much further away (from the house) than the cabinet is. They can't both be right.

The node itself is just a set of splice trays, and is obviously meant to be a point where the shared PON fibres splice back onto the main fibre distribution routes. They perform an identical job, logically, to the PCP - the distinction between E-side and D-side.

Given that we're reusing ducts for the fibre rollout, it makes sense if the aggregation nodes are somewhere on the main distribution routes for E-side cables (for example, along main arterial roads), and probably close to the cabinets, even if they don't exist 1:1.

BT's FTTP (and FTTPoD) architecture doesn't seem to have a secondary splitter, but there is no real reason why they couldn't if they wished to. They do have a DP node (more splice trays) and place a manifold in the final leg, which seems to be the joint between the BFT underground and the BFT in the fibre "drop cable" - presumably to make drop cables easy to change, while still allowing the fibre to be blown.

I've seen that the splice trays at the home and in the DP tend to be marked with some kind of "fibre lock" symbol, where the aggregation node and splitter node trays don't. I presume there's an architectural reason for that too.

In reply to a post by WWWombat:

Right now, we don't really know where the aggregation nodes are. Some of the architecture diagrams make it look like one exists near the exchange, while the distance estimates in PR for FTTPoD make it seem like Aggregation Nodes are not much further away (from the house) than the cabinet is. They can't both be right.

More than one node on a path, both can be right. ANs are where individual branches of fibre aggregate on their way to the root/spine at the headend.

Could these aggregation nodes be disguised as large black bollards (looking similar to this) which stand up on pathways near ducting?

The reason I ask is we've had FTTC for a couple of years now but the other end of the estate has only just had its cab installed.
At pretty much exactly the same time there appeared a large black bollard where the outer casing slips off (I saw a contractor working on it - definitely looked like a cable/fibre junction point of some kind - it's a main road so I couldn't easily slow down to take a better look).
It stands around 750mm to 1m high.

There are no other developments going on in the area (apart from a long way off planned housing estate). There are no commercial buildings nearby, the school already has its fibre connection, we have no cable TV in the area and the road (albeit a busy one) doesn't really go anywhere - it's just a spine/access road linking around 1,000 homes to two major A roads going in/out of town.

There aren't any others around town (and the rest of the town has had FTTC for a couple of years - this was just the last cab to be installed - also it's the most recent voice cab to be installed in town - I'd just figured it was so new it hadn't made it onto whichever outdated list BT use to work out where to stick fibre cabs).
Can't think what it could have been (other than one of these famed aggregation nodes).

BTW; it's around 1.5 miles from the exchange.

Edited by adebov (Sat 25-May-13 15:37:11)

I would be surprised if BTOR would install such equipment in a bollard, They will most likely be underground in a chamber, (more secure down there)
Hence why no one knows where exactly they are located apart from BTOR of course

All the FTTH is underground or pole mounted.
I suspect what you see in the bollard is a utility (probably water company) remote telemetry unit, probably monitory water flow

http://www.coolwebhome.co.uk/fibre-milton-keynes/wgc...

Most fttp kit is in that picture. Ag node on left, splitter on right, manifold at bottom and splice tray that goes on house wall outside in middle

and splice tray that goes on house wall outside in middle

CSP (customer splice point) get with the acronyms daddy-o.