Technology developed to possibly get 250mb/s speeds out of telephone lines

meepins

http://www.news.com.au/story/0,23599,22639169-421,00.html



A MELBOURNE PhD student has developed technology to make broadband internet up to 200 times faster without having to install expensive fibre optic cables.

Harnessing the potential power of telephone lines and DSL broadband, the technology will deliver internet speeds up to 250 megabits per second, compared with current typical speeds of between one and 20 megabits per second.

Dr John Papandriopoulos, who has patent applications for the technology being processed in the US and Australia, won one of Melbourne University's top academic prizes yesterday, a Chancellor's Prize for Excellence in the PhD.

Telephone wiring was poor quality and was not designed for high-speed internet when it was created, Dr Papandriopoulos said.

"Back in the old days, if you picked up the phone you could hear your neighbour's conversation from cross-talking interference," he said.

"While that doesn't happen any more with voice calls, it does with the broadband internet - your telephone line interferes with your neighbours and everyone in your street's internet."

Dr Papandriopoulos' research, which took a year to complete, uses mathematic modelling to reduce the interference that slows down downloading.

I haven't come across any technical details yet but if Melbourne Uni are awarding a prize for the work it must have some legitimacy. Is anyone else familiar with this news and its application?

AlmightyCushion

Doesn't vdsl2 have speeds of up to 250mbps? I know the speed decreases a lot over distance but imagine the two of these combined. :eek:

Slutmonkey57b

It's in today's INQ but the question is if this tech reduces line interference that much, will it make eircom's shoddy copper viable for people who have been failing line tests for years?

No sign of a real-world test yet though so we've a few years' wait yet.

I await the Sponge's comments with baited breath.

Sponge Bob

Slutmonkey57b wrote: »

No sign of a real-world test yet though so we've a few years' wait yet.

Well you said it all in fairness. slutmonkey, I can only make a supplementary observation or two.

I await the Sponge's comments with baited breath.

Once upon a time ( around ten years ago) the fastest modem in the world was developed in GALWAY.... analogue modem that is . The company was Toucan Technologies IIRC.

It could do a stonking 1mbit . It never saw deployment .....least of all in Ireland on eircom lines

Mind ya if yer man has worked out a good solution for crosstalk it could creep into standards like VDSL3+ or ADSL3+ if the licencing has been arranged in a sensible and equitable manner . Otherwise maybe VDSL4 or ADSL5+

Mathematical squelching of crosstalk is indeed an important goal if one is to squeeze more out of copper.

crawler

DSM and technologies such as MIMO (already deployed in wireless world) are widely touted as the next advancements in eliminating cross-talk interference in DSL.

Professor Cioffi is the daddy of DSL - his work on DSM can be read here :-

http://www.stanford.edu/group/cioffi/dsm/

There are a whole pile of ways that 205Mbps+ could be achieved - Wimax, for example, grew out of DOCSIS and so did parts of DSL. "noise" can not be eliminated - the trick is how to ignore it and use the ENTIRE scope of the copper for relevant signal. When all telco's more to IP everything, questions will be asked if the CLFMP is still relevant and how indeed the entire possible spectrum band in coper should be utilised. What would be interesitng would be cross-talk guard bands and various OFDM techniques along with DSM and MIMO and maybe even an electrical equvialent of beam forming (applauds Navivi for getting all bought by Cisco!!) - If anyone wants a really pointy headed discussion on this. let me know!!

PS - if someone does create a box that will do 100Mbps on all the phone lines in the world, you might let me know also?

Sponge Bob

crawler wrote: »

PS - if someone does create a box that will do 100Mbps on all the phone lines in the world, you might let me know also?

LOL , I am sure that you will know before any of us and that you may even have your grubby hands on it before the rest of us know its in the wild

The main concern that I have is that academia is not as good at converting ideas into Intellectual Property ( the other IP) and thereafter into licencing to manufacturers and finally into ITU or DSL Forum standards.

No idea is worth a fig until it makes it into a standard from which it goes into mass production and deployment .

Send me a PM when you want me to Host the Terminal in the hostile wilderness that is rural Ireland , I will give it a good rattle so I will.

watty

I can do 1Gbps on a phone wire. But not for very far.

If people are prepared to pay, one method to get more speed is multiple pairs. "Pair loss combiners" instead of pair gain splitters.

The voice band is not that big, you maybe could use QAM512 on it. One idea is instead of a single QAM on OFDM is to use progressively higher QAM on lower frequency bands, so maybe QAM1024 up to 2Khz (= 2Mbits raw) and then QAM 512 on 2kHz to 4KHz (1Mbps raw), QAM 256 on 4kHz to 8KHz (1Mbps raw), QAM 128 on 8KHz to 16KHz (still 1Mbps raw) ... etc
So maybe get 6Mbps at 8km on "average copper".

If CDMA principles are used to shift the OFDM carriers on neighbouring pairs, then crosstalk my be slightly reduced.

Dunno. never done the detailed sums. But there is no doubt that with current hardware some enhancements may be possible even just with firmware upgrades. Maybe even variable FEC (lower on UDP and higher on TCP as faulty TCP are resent and the theory of UDP is to accept a certain amount of errors).

thebman

There is another article here with a quote from the inventor:
http://www.theregister.co.uk/2007/10/25/aussie_phd_dsl_turbo/

We formulate a (standard) model for how DSLs attain their data-rate, considering crosstalk interference effects. We exploit the fact that interference varies across the frequency spectrum, and that if we are clever about the way in which we allocate transmission power amongst the various frequency bands, we can manage the interference between (strongly) coupled lines. For example, one user that interferes strongly with others within a band may be "turned off" within that band to avoid damaging the other lines, consequently raising the overall network rate.

I don't his use of the words turned off. I presume that means moved to another band and not just disabling the whole connection for a user interfering with other users because if his solution is to turn off people causing interference, I think I might have been able to come up with it myself.

Sponge Bob

Well lets see if he can get it into a G. and/or TR- standard then because the CPE will have to report back to the exchange and tell tattle tales

crawler

SB - you hit the nail on the head - there are LOADS of great ideas out there that never become commercial offerings.

Theory is one thing, delivery is another. Sadly many good idea from our academic friends, never see the light of day.

Problem with many of the very good solutions outlined by various parties is that nearly all copper plant is different and unique in how it's deployed - this makes a "one size fits all" fix almost impossible.

Watty - the sums will wreck your head - save yourself the effort and ignore it!

Best way to eliminate electrical ingress and egress noise is to make it go away - the BEST way to do this is to deploy fibre But sure ye all know that

watty

Little robots carting the fibres up the sewers...

Oh wait... lots of folk have septic tanks and we are 20 years behind promises on Treatment Plant and "network" upgrades.