FTTDP, FTTRN and G-Fast. Oh my!

Update 08-07-2014
BT finally starts a small-scale trial of FTTRN to 16 properties at Gwent Court on Rotherhithe Street.
Update 27-12-2014
BT to now pilot for a “new form” of Fibre-to-the-Basement / Building (FTTB) broadband technology in the City of London.
Update 09-12-2014
BT is now planning to trial an FTTRN solution in Rotherhithe.
BT has several technologies currently on trial that may potentially help resolve the issues with slow broadband in Rotherhithe. These will be put forward as solutions to Southwark Council but they may be sometime away from being implemented.

As many of you know, most people get their telephone line via a green street cabinet. BTs normal super-fast broadband roll-out – Infinity uses an additional green cabinet installed near the existing cabinet. This new cabinet houses a fibre line from the exchange which connects to the copper cable in the existing green cabinet and then on to your home. This is FTTC (Fibre-to-the-Cabinet). Rotherhithe doesn't have many green cabinets and so cannot have Infinity.

Node / distribution pointFTTRN (Fibre-to-the-Remote-Node, also known as Fibre-to-the-internal-cabinet) sees the fibre optic cable from the exchange being taken to a significantly smaller ‘Remote Node’. A remote node is typically an underground chamber where larger copper cables are split into bundles before being fed to distribution points which usually serve around 7-8 properties. BT are also looking at FTTDP (Fibre-to-the-Distribution-Point). Theoretically this will bring the fibre optic cable very close to homes, which will mean faster and more stable speeds.

Installing a new fibre cable to a remote note or distribution point will allow the node/distribution point to act like tiny street cabinet. The advantage with this approach for Rotherhithe is to avoid the need for re-routing existing copper cable or building a new street cabinets.

Along with where to place the new equipment, BT is also looking at what type of equipment to use. The main focus of this is to increase the speed of connection over the last piece of copper from the cabinet, node or distribution point. This technology is known as G-Fast and is the latest standard for transferring data over copper wires based on existing DSL technology. (ADSL is currently used for long lengths from the exchange and VDSL for shorter lengths from a street cabinet).

G-Fast increases data transfer speeds over very short distances of copper wire (250m max). The technology has been shown reach speeds of almost 1Gbps over 20 meters but as the copper length in the real world is likely to be much longer, speeds of 200 - 500 Mbps are more realistic. The new equipment will require power but it may be possible that this power comes from the home via the copper cable, especially when FTTdP is deployed.

BT’s trials are designed to help them understand a variety of difficult factors, such as the costs of deployment and maintenance, as well as the impact on performance and time to install. Trials have been taking place at their research facility in Martlesham as well as in other locations with one about to start in Shoreditch.

BT currently sees these new technologies as having the potential to fill those awkward urban and rural gaps, where their existing approaches might be less cost effective.

Advantages
Potentially faster speeds than current FTTC (Infinity 1&2).
No need for new cabinets.

Disadvantages
Availability. Technology is still in trials with no confirmed availability. BT Openreach have stated that the service will not ready for deployment before end of 2015 at the earliest.
Time to deploy – even though FTTRN/FTTDP may prove quicker than installing new cabinets and re-routing cables, it will still be a time consuming and costly endeavour.
Contention. As with all BT Infinity products, the connection is contended, meaning many customers will share the same fibre line.

Questions
No pricing has been announced. This will depend on the results of the trials and where BT places the product in its Infinity line-up. FTTRN may be marketed as a premium product, similar to Infinity 4, BT's 300Mbps service costing £50/m.