Released: January 2009
By Carsten Storbeck, director of product management with ADC KRONE
Fibre-to-the-home (FTTH) is going to happen. In some countries it is well advanced with customers enjoying data speeds of 100Mb/s into their homes. In other countries, carriers are trying to squeeze the last couple of years out of their aging copper networks, but the best they can achieve is around 50Mbit/s that simply isn’t going to be enough to satisfy consumer demand in the coming years years.
Running fibre to every home is not difficult – but the process of digging-in fibre is expensive. Nonetheless, it will have to happen sooner or later or the telecoms companies will find their business taken by the cable TV operators.
One particular area that is proving especially difficult is once the wireman actually gets inside the building.
In America, where FTTH (fibre-to-the-home) is in some regions quite prevalent, over 70% of the housing stock is single detached dwellings that are not a great problem.
In Europe, on the other hand, over 70% of us live in flats, apartments, terraces or town-houses, now collectively referred to as MDUs or Multi-dwelling units. These are far more difficult to fibre-up.
In the good old days, cabling up such a building for telephony was easy. Either a multi-pair “dropwire” or underground cable was terminated onto a DP (distribution point) and two or three pair cable run to each dwelling or, in larger buildings, the incoming cable went to a DP (probably in the basement) then a multi-pair riser to a DP on each floor and finally small cables to each dwelling.
In new buildings, the cables would be concealed in risers and conduits or trunking and in older buildings they would be carefully run up staircases and around skirting boards, through doorframes and so forth.
A new scenario
Now let’s come up to the present. We need now or in the near future to deliver 50 or 100 Mb/s, perhaps 1Gb/s, to each dwelling. We could use Category 5e/6 cable but this can only run 90 metres from the active electronics that terminates the external fibre connection. Plus, this has the severe disadvantage that Telco electronics has to be housed in the basement and fed with electric power – probably with battery standby UPS (uninterruptable power supply) too.
A far better alternative is to take fibre right the way to each and every dwelling in the MDU – but until now this has been a difficult and costly process.
Currently, the building has first to be surveyed; all fibre routes worked out and measured with extreme accuracy. The survey has to be passed back to the office and into the purchasing system. A ‘special order’ has to be placed on a fibre cable manufacturer and special-to-length cables produced.
Some three or four weeks probably pass before the cables come into stores and the job can be allocated to a site technician.
Alternatively, the site technician can carefully run in the fibre cable risers from basement to each floor where fibre distribution points are placed then smaller fibre cables from these fibre DPs to each dwelling.
All of this with great care, because everyday fibre cables do not happily tolerate the rough treatment that copper cables can be subjected to, nor will they tolerate right-angle bends or being stapled to skirting boards and the like. So fibre cables do not fit well with the technicians’ current on-site working methods.
Either a skilled (and therefore expensive) fibre-splicing technician has to do the whole job or, once the cable-laying is all done, one has to be summoned to site to splice all the fibres at the basement DP, per-floor DP and each customer’s dwelling. Often this can mean a hundred or more splices are needed. A long and very expensive process – more so as every splice has to be tested.
So until now, fibering-up a multi-dwelling unit has been an expensive business. Until the recent launch of fully-modular plug-and-play MDU fibering system by ADC KRONE that is.
The new breed of MDU fibre system includes fibre cable developed out of military experience that not only can be stapled to skirting boards and architraves without damage, bent round every type of right angle found in buildings (and on average every horizontal run needs to go around 15 right-angles) it can even be run over repeatedly by a Chieftain Tank without either damage or degradation of signal.
The real piece-de-resistance though are fibre distribution points ( called fibre distribution hub and fibre distribution terminals) that have a hidden, in-built fibre cable-reel pre-loaded with a preterminated 30, 60 or 90 metre fibre cable to run back to the previous DP.
In fact there are only four components and even with the different fibre-length variants only nine component variants, all of which can be stocked and kept in the technician’s van.
This means that with a stock of these nine variants in his van the wireman can simply turn up and start work. There’s no need for a site-survey and no need for a four-week wait while special-to-type fibres are manufactured.
In the new scenario it is unbelievably simple.
A fibre distribution hub (FDH) is wall-mounted in the basement or near the external fibre cable entry point. This can come complete with an external fibre-cable stub to run out to the external fibre splice enclosure or can optionally have splice-trays for termination of the external fibre. But from here, it’s totally plug and play.
On each floor, a fibre distribution terminal is mounted on the wall. Behind the active fibre-connection box is a fibre cable reel pre-loaded with up to 200 metres of 12- or 24-fibre cable with an MT-type multi-fibre connector.
The wireman simply pays-off enough cable and feeds it back to the FDH in the basement. (On larger jobs possibly via a fibre collector unit on a higher floor.) Having run the cable, he simply plugs it into the FDH and re-traces his steps, stapling or affixing the riser cable through risers, along staircases or even up exterior walls.
Similarly, in each dwelling he attaches an OLT (optical line terminal) in the customer’s dwelling and then runs a preterminated fibre back to the FDT. Stapling along architraves, skirting boards and through door frames and the like as he goes. Once again he simply plugs the second preterminated end of the customer fibre into a port in the FDT.
Finally, because the fibre cables are all factory pre-tested, the only testing that’s needed is to check for signal levels in each customer dwelling.
With this novel approach, the whole process is every bit as simple as running in old-fashioned copper cable. Simple, durable, long-lived and far less expensive then existing MDU fibre distribution.
Summary
By adopting their pre-configured system no pre-surveys are needed and no lengthy ordering cycles for provision of special-to-type fibre cables. The only splicing that is required is in the external splice enclosure or the FDU to terminate the external feeder cable instead of an expensive splice technician being needed to terminate hundreds of fibres on every floor and dwelling. Component costs are less because there are only nine component variants all of which can be held on the wireman’s van. Experience with major telecoms carriers in the USA has shown that these MDU installation costs have been reduced by 60 percent. Finally all of the equipment has been proven in both CO and field environments.
About ADC KRONE
ADC serves its customers as ADC KRONE in the Europe/Middle East/Africa, Asia, and Indo-Pacific regions of the world. ADC KRONE provides the network infrastructure equipment and services needed to deliver voice, video, Internet and data communications around the world. Wireline, wireless, cable, enterprise, and broadcast network operators rely on ADC offerings to deliver bandwidth intensive, high-speed services to residential, business and mobile subscribers. ADC (NASDAQ: ADCT) has sales into more than 130 countries. Learn more about ADC KRONE at www.adckrone.com
AK1361
ADC KRONE, Structured Cabling | Debbie Ireland | 
January 13, 2010 1:44 pm | 
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