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Say hello to new 1Gbps ITU G.9700 standard
Tuesday 16 July 2013 18:20:37 by Andrew Ferguson

The RF geeks are finding ways to utilise the increased processing power of modern DSP chips to now push Gigabit type speeds over short runs of twisted pair telephone cable. G.fast has reached a key milestone with the initial approval of the standard by the ITU and the designation of the name G.9700.

This new standard promises aggregate speeds of 150 Mbps over 250m of telephone wire and much faster speeds on shorter lengths such as 650 Mbps over 50m. This is achieved by using a much wider frequency spectrum than VDSL2 (profile 17a in the UK currently has a maximum frequency of 17 MHz), G.9700 stretches all the way to 212 MHz and the new standard takes into account the requirement to avoid destroying FM radio reception.

For those where full fibre optic connectivity with a fibre into the home is the only real solution this new standard will be seen as a waste of time, but the appeal to the telecoms operator is that you can run fibre to a small unit serving a dozen or so customers from a pole, pavement chamber or even install the kit in the telecoms cupboard of a block of flats. This avoids the need to gain entry to every property and that final run across peoples property, which if old estimates of 7 hours per install from Openreach for FTTP are correct will be welcomed.

It is unlikely that G.9700 will have any impact on the current BDUK projects, as full ratification is not expected until 2014 and there will then be a couple of years before anyone decides to deploy commercially. Thus G.9700 is probably more about extending speeds in a post 2018 broadband landscape.

Tracking down solid information on upstream speeds is proving difficult, but one key aspect is that crosstalk can have a major impact on G.9700 performance meaning we are likely to see the vectored variant if the aim is to get the best possible speeds. Alcatel-Lucent has some useful data on the performance of G.fast/G.9700.

Comments

Posted by lockyatlrg over 3 years ago
ofcom will find a away to wash down this standard or point blank refuse it

on the plus side I did have a nice short .5 line :D
Posted by chrysalis over 3 years ago
granted ratification be in 2014, that probably mean a 2020+ rollout from BT anyway.
Posted by timmay over 3 years ago
As the distance is so short this is really only useful within blocks of flats where the cabling is only twisted pair. Where I live the internal cabling from the DP is Cat5e so they could simply use gbit Ethernet.
Posted by WWWombat over 3 years ago
Short distances, but still useful in the wider network. You just need to have new nodes for the job, and not rely on the current cabinets.

G.Fast is designed to co-exist with FTTdp - so the nodes will likely be placed at or around the DP. Swisscom call this FTTS (S=Street).

Posted by WWWombat over 3 years ago
Note that G.Fast comes with vectoring as a standard, and very necessary, component - no added variant required.

Telekom Austria have run some trials with typical older copper. They got 500Mbps over 100 metres (single pair) either as a single subscriber, or with vectoring turned on. With multiple subscribers and vectoring turned off, it dropped to 50Mbps.

Good article here, including migration scenarios:
http://www2.alcatel-lucent.com/techzine/the-numbers-are-in-vectoring-2-0-makes-g-fast-faster/
Posted by WWWombat over 3 years ago
@chrysalis
Agree. If it follows the speed that both VDSL2 and Vectoring have been going post-standardisation, we're looking at >2018 to be mainstream.
Posted by Dixinormous over 3 years ago
Fully expecting vectoring, pair bonding and phantom pair technology to be deployed before this is contemplated.

Those push 300Mb out to 400m with 2 physical pairs. Far from shabby.
Posted by JNeuhoff over 3 years ago
@WWWombat: "we're looking at >2018 to be mainstream" By that time everyone will know what real fibre-broadband actually is, as opposed to old copper VDSL. VDSL is nothing more than a transitional phase, often financed by load of wasted public money in return for nothing.
Posted by ScubaGirl over 3 years ago
Upload speeds are already being artificially held back on existing FTTC and FTTP connections. The backhaul systems are already set up for handling the faster speeds, but it is set lower for the consumers. I guess that the current servers or political decisions stop us from appreciating such speeds.
Posted by GMAN99 over 3 years ago
@JNeuhoff its called value for money, getting the most of out what money you have available, its not a new concept and one that works well in business
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