Kitz Forum
Broadband Related => Broadband Technology => Topic started by: GigabitEthernet on October 10, 2012, 07:56:12 AM
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Hello everyone,
There is no fibre available to me as I am on such a small exchange but it can't stop me asking questions can it?
Anyway, if one has a telephone line coming to their house via a telegraph pole and it is like that for the majority of the journey to the exchange, how is FTTH installed? Sorry if that is a silly question.
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The normal scenario would see the Fibre cable being pushed underground to the foot of the DP (Telegraph Pole), where a Fibre Joint would be in place. The engineer then runs a tiny flexible duct from here up the pole and to the premises. The Fibre is then 'Blown in'.
Now, as I have no Exchanges FTTP enabled on my patch, I'm no expert, but I am pretty sure that there are overhead fibre cables that have been trialled and passed as suitable. Perhaps there's Walter, BE or BKCAT or similar who have more in-depth knowledge on this ?? :)
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I have no practical experience but from my reading of various articles, etc, I can confirm that the pole-top to premises fibre micro-tube ducting is the more convenient and simpler to install.
The interesting part of AR's question is how is the fibre brought to the DP when the whole D-side (for example) is overhead, i.e. all aerial cabling, in a FTTP on demand situation. And that I do not know. :no:
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I would suggest that with FTTP installs it would use the existing Duct work for FTTC and then from there go via the Ducting up the pole and to the house.
Or if it is exchange to site, through exiting duct, then to a Fibre Junction and up the pole and across.
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Azzaka, the problem is a heck of a lot of D-side cabling is 'Not ducted', ie- most rural/semi rural dwellings will be fed via 'Armoured Cable' or (as in the OP's case), long runs of overhead (Aerial) cable.
10mins of digging on out internal systems reveals that FDC (Fibre Drop Connection), can not only be used as 'The last span' from DP to Premises, but also as a pole-to-pole service as well. So, rest easy arob, you'll get Fibre eventually. :fingers: ;)
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10mins of digging on out internal systems reveals that FDC (Fibre Drop Connection), can not only be used as 'The last span' from DP to Premises, but also as a pole-to-pole service as well.
Thank you for checking, BS. :) I just hope it wasn't 10 minutes of one of your infrequent breaks . . . :-X
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Ha ha ..... it was 'investigated' all in my own time, B*Cat. ;) ;D
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Then you must surely now be due :drink: for that dedication.
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Azzaka, the problem is a heck of a lot of D-side cabling is 'Not ducted', ie- most rural/semi rural dwellings will be fed via 'Armoured Cable' or (as in the OP's case), long runs of overhead (Aerial) cable.
Me being a case in point - a rural area though quite close to a city (green belt).
Ducted from the exchange to the individual cabinets.
Then the D sides all run underground direct in the ground unducted just on the road verge.
This lot has been there so long that whole trees have grown up located over the cable run line.
At various points jointboxes split out the cables for the next group of houses and these are then run up to the distribution point on a pole and thence to a property. Indeed some unfortunte properties do have very long drop wire lengths back tracking along the road in multiple poles from the nearest pole mounted distribution point.
Costs for ripping it out and ducting this lot? Take my cabinet - it serves 4 roads, on average about 1 mile each so 4 miles of ductwork to be done. Ductwork cost - guess at £100/m including the VAT. Add on the costs of new joint boxes something like £3K each plus ancillaries and you'r approaching £0.5million just for 1 cabinet.
Well it ain't going to happen is it
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Just a heads up .... not quite £100/Mtr. Last time I asked, it was approx £45/Mtr in tarmac/flags etc, and £30/Mtr in soft (grass etc).
But still a very valid point c6em.
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this may interest those that didnt know what "Fibre is 'Blown in' from there" meant....like me :)
http://www.madisontech.com.au/copper-cable/category/blown-fibre
also this shows how FTTP is installed etc :)
http://www.pcpro.co.uk/blogs/2010/10/28/the-real-reasons-we-have-to-wait-for-bts-fibre-to-the-premises-broadband/
BT Openreach FTTP Modem
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.pcpro.co.uk%2Fblogs%2Fwp-content%2Fuploads%2F2010%2F10%2Fbox2-462x346.jpg&hash=b631b2e2650f6cbfdacc5c735ad313b85bb2b7aa)
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For those who have not seen an aerial fibre feed, attached below is an image showing a fibre manifold (left) and a metallic DP (right) at a pole top.
Notice that everything else is pretty standard at the top of that pole -- the "halo" ring, the galvanised steel "twiddles" to anchor the drop-cables or fibre tubes to the "halo", etc.
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thanks B'Kat :)
Im still unsure of the relation between a 'Manifold' and 'DP'..? why cant the fibre be run directly into the DP..?
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The DP has a multi-pair cable entering it and individual pairs exiting it which lead off to the various premises.
The fibre manifold has a fibre feed entering it and individual fibres exiting it which lead off to the various premises.
Suppose it was physically possible to accommodate both metallic and fibre connections within a dual-purpose DP, what would happen when a standard metallic pathway service develops a fault which requires a technician to access that (hypothetical) dual-purpose DP? If it is just a PSTN (metallic pair, telephony trained) technician, blundering-Barry or nervous-Nora, should s/he be allowed to access a device containing fibre junctions? Or will he have to defer the fault fixing to a multi-skilled technician, a super-Black Sheep?
Now consider what the fitting of that (hypothetical) dual-purpose DP would entail. All existing services via the old metallic DP will suffer a service interruption whilst it is disconnected and the new device is fitted. Would you be happy with that state of affairs if you were served by that DP and had no interest in fibre feeds, etc? :no: :-X
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thanks for that explanation, I see what you mean when it concerns PSTN (copper).. just in the article I posted from PCpro it says the Fibre enters the DP then the MANIFOLD..?? or is that incorrect? (see below)
sorry for the masses of confusion from me, I suppose it depends on how he explains it - I suppose the same theory is applied to fibre only connections where by keeping the last DP with a small amount of customers on for less disruption if that DP has problems. Just I though each customer was on its own terminal so problems with one customers line didnt affect others, guess fibre doesnt work like that because in the article it says the fibre is 'split' and shared between customers...is that right?
(https://forum.kitz.co.uk/proxy.php?request=http%3A%2F%2Fwww.pcpro.co.uk%2Fblogs%2Fwp-content%2Fuploads%2F2010%2F10%2Fhole.jpg&hash=765193bb3fea166beb783743718ca5137051e6a6)
http://www.pcpro.co.uk/blogs/2010/10/28/the-real-reasons-we-have-to-wait-for-bts-fibre-to-the-premises-broadband/#ixzz29N9rrQW2
From each exchange in the test area in Milton Keynes, cables with a dozen fibres feed out to a splitter. There, each is fibre is spliced and split out to supply 32 customers — although BT usually keeps two aside for backup. The fibre winds its way through tubes in subducts to a local distribution point and a device called a manifold, which shares the fibre connection out to up to a dozen properties, but usually about half that.
(See that little hole in the wall at the top of the picture? That’s where all the cables need to go through. The device on the left with the cables feeding in is the distribution point, while the black tube on the right is a manifold.)
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That picture of the pole-top fibre manifold is from an area where FTTP is being deployed as an "add-on" to the existing metallic path telephony service. In that area it is as an aerial feed.
Attached below is a section excised from an Openreach document showing how FTTP would be deployed in a totally underground fashion, again for an area that has an existing metallic path telephony service.
The ultimate aim of "fibre only" (no metallic path) exchanges is being trialled at the moment -- I don't have a reference link to hand paw, so perhaps someone else could provide it, please.
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Trial is being proposed for Deddington, Oxfordshire.
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thank B'Kat
so is it true that fibre is 'shared'..? im probably reading it wrong but it does say (on the PC Pro article)
cables with a dozen fibres feed out to a splitter. There, each fibre is spliced and split out to supply 32 customers
if thats true, how do they keep connections separate? colored light? lol... if thats the case then are you 'sharing bandwidth' to some degree..?
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Trial is being proposed for Deddington, Oxfordshire.
Ah, yes. Thank you kindly, c6em. :)
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cables with a dozen fibres feed out to a splitter. There, each fibre is spliced and split out to supply 32 customers
if thats true, how do they keep connections separate? colored light? lol... if thats the case then are you 'sharing bandwidth' to some degree..?
Well, at the simplest of levels, yes. Different coloured light has a different frequency and that particular carrier-frequency can be modulated with a number of multiplexed signals . . .
And as for 'sharing the bandwidth', again, yes.
Although I have an overall 'feel' for the system, I am not able to explain it in a clear fashion. :no: Perhaps another of our fellow Kitizens would like to help out?
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Perhaps this might help explain it......
http://en.wikipedia.org/wiki/Wavelength-division_multiplexing
....Warning: You may lose the will to live half way through this article !
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Oooh, questions, questions, questions :-X
Nice pic of the pole-top fibre, didn't realise the technology was ready to do that. I want one on my DP, now :baby:
So does FTTP/H always do away with the PSTN copper network, i.e. your phone service would operated over the fibre too?
And why the hype about FTTH 'on demand' in already FTTC enabled areas, is that a different method of deployment?
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On demand (FoD as it's being marketed), had its first installation only recently (25th Oct 2012). It was actually one of our own fibre engineers premises that had it installed. Got to be a perk of the job somewhere, I suppose.
Engineering trials (Phase 1) are continuing until March 2013, with 'Phase 2' (planning, order placements etc) to continue after this.
Smu ..... FTTC only has Fibre connected to the Cab, it still utilises the existing Copper/Ali D-side cable for the 'last mile' to the EU's premises. FoD will see the laying of UG (Underground) Fibre or OH (Overhead) Fibre direct to a DP (Distribution Point) manifold, then into the EU's premises.
HTH. :)
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Sorry, I meant to ask is FoD any different from FTTH?
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Errm, yes and no. The end product is the same, the delivery method is different.
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Dare I ask >:D How is the delivery method different? :)
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FTTP = If you are lucky enough to live in a FTTP Exchange Enabled area, when you request a conection to Fibre broadband, you get what it says on the tin ........... a fully fibred up connection. From my time 'shadowing' the fibre planners, there are no 'Cab connections' that I'm aware of on FTTP.
FoD = (Caveat - still undergoing 'trials' as previously mooted), means you will have previously only been connected as a FTTC customer. I'm guessing the EU will have to foot 'x' ammount of the additional work in order to 'push' the fibre from the Cab to the EU's premises.
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Thanks Black Sheep, I realise this is stuff is new and probably subject to change, but as b*cat will confirm, I'm most curious ::)
So what we can surmise is that FoD's fibre is run from the nearest FTTC cab and thence in new tubes either U/G or to the pole base and on to the sub (sorry customer). I thought I heard the term 'from the nearest node', but perhaps that is close to the cab anyway? ;)
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Thanks Black Sheep, I realise this is stuff is new and probably subject to change, but as b*cat will confirm, I'm most curious ::)
So what we can surmise is that FoD's fibre is run from the nearest FTTC cab and thence in new tubes either U/G or to the pole base and on to the sub (sorry customer). I thought I heard the term 'from the nearest node', but perhaps that is close to the cab anyway? ;)
The term 'Node' covers most aspects of the network, including PCP's, DP's, Cable runs .... etc etc .......
Therefore, if there is an existing 'Fibre loop' nearer to the EU's premises than the actual FTTC Cabinet, then I can't see any reason as to why they couldn't splice into it. I would imagine this situation would be in a minority though ???