November 12th, 2007
ADSL at 250 megabits per second?
Some of you are old enough to remember that it was usual to catch a conversation between complete strangers when you were calling someone on the phone. This phenomenon, called cross-talk, also affects ADSL broadband connections today. But according to the Sydney Morning Herald, an Australian researcher, John Papandriopoulos, has developed an algorithm to reduce that interference. Of course, this means that ADSL connections can be faster. He says the new technology could deliver between 100 and 250 megabits per second. And it could become available worldwide within two or three years.
You can see on the left a photo of John Papandriopoulos, a research fellow at the Centre for Ultra-Broadband Information Networks (CUBINlab). Papandriopoulos completed his Ph.D. in 2006 within the Department of Electrical Engineering at the University of Melbourne, Australia. The picture on the left shows Papandriopoulos handling a “Ph.D. submission balloon” on October 25, 2006. (Credit: John Papandriopoulos)
Here are some quotes from the Sydney Morning Herald article. “‘Many years ago people used to pick up the phone and make a phone call and you’d be able to hear a faint or distant telephone conversation taking place, and that’s called cross-talk,’ Dr Papandriopoulos said when attempting to explain how his algorithm worked. ‘That is not an issue for voice calls these days but it becomes a problem when you’re trying to wring more bandwidth out of these existing copper telephone wires [which power ADSL broadband connections]. This cross-talk in current day DSL networks effectively produces noise onto other lines, and this noise reduces the speed of your connection.’ Dr Papandriopoulos said his algorithm served to minimise that interference and thus maximise the line speed.”
In an October 23, 2007 news release, the University of Melbourne announced it gave Papandriopoulos a Chancellor’s Prize for Excellence for his research. It also gives additional details. “Dr Papandriopoulos developed two methods — patented as SCALE and SCAPE — as part of his PhD in the University’s Department of Electrical and Electronic Engineering. He says the new techniques can dramatically reduce the interference which slows down data transmission in typical DSL networks and use less power in the process.”
But this news release doesn’t provide details about the algorithm, except this. “Dr Papandriopoulos used complex mathematical modeling and optimisation techniques to develop the system, which he says can be used with existing telecommunications networks without laying kilometers of expensive fibre optic cabling. He says to facilitate the faster data transmission speeds, telecommunications providers would need to change their operational systems and consumers purchase new modems.”
Of course, I wanted to know more and read more about Papandriopoulos research, but here is what he writes on his home page. “My Ph.D. dissertation is currently bound by a confidentiality agreement due to intellectual property issues. It will be made available on my website in PDF form as soon as these restrictions are lifted.”
I can understand why. Lots of money are involved. And by the way, Papandriopoulos got a new job at ASSIA — which stands for “Adaptive Spectrum and Signal Alignment), a start-up company developing new ways to optimize the performance of DSL networks, and chaired by Stanford University engineering professor John Cioffi. Here is what states Papandriopoulos about the future of ADSL. “Research by Prof. John Cioffi’s group at Stanford University has recently concentrated on the next-wave of DSL technology, that can offer speeds of 1-2Gbps over copper. That research, however, is likely to be many more years away from implementation and deployment. Our technology can assist with raising broadband speeds over DSL in the much shorter term.”
Sources: Asher Moses, Sydney Morning Herald, November 5, 2007; and various websites
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