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New Technology to Push 40Mbps DSL over Existing Copper Wire

by February 25, 2008
DSL gets a speed boost!

DSL gets a speed boost!

Rim Semiconductor Company may breathe new life into the existing copper wire infrastructure, allowing phone companies that offer Digital Subscriber Line (DSL) to significantly boost speeds:

Rim Semiconductor is introducing a new data transfer specification that they are calling Internet Protocol Subscriber Line (IPSL) that when driven by Rim’s new Cupria transport processor is said to achieve data speeds of 40 Mbps at 5,500 ft radius on existing 26AWG copper telephone wire and 26 Mbps at a 6000 ft radius.  This is a significant speed boost over current top DSL speeds of 6 Mbps typically available.  It is also a big jump from AT&T's U-verse that recently announced an upgrade that will push speeds to 25 Mbps total with IPTV service including 10 Mbps dedicated for internet service, which will initially be limited availability.

Rim is looking to provide traditional telephone companies a cost effective way to better use the existing copper wire that serves 1.4 billion end users.  According to a marketing paper available on Rim’s web site, IPSL costs significantly less to deploy than alternate VDSL technology, which incidentally U-verse is based on, potentially yielding up to a 56% cost savings while providing greater customer coverage.

Telecoms like AT&T and Quest typically run fiber to distribution nodes but rely on existing copper for transmission to the end users, which is referred to as a fiber to the node (FTTN) network.  An increase in end loop speeds will allow AT&T to put the recent 40 Gbps network backbone upgrade to good use.  Also, an increase in transmission speeds to 40 Mbps will put DSL services back into the pack with competing services, for the time being at least.

At present, Verizon runs 30 Mbps downstream and 15 Mbps upstream bandwidth with FiOS, but the service costs nearly $160/month.  FiOS is an implementation of VDSL based on a fiber to the premises (FTTP).  The high service price reflects the significant cost of laying fiber for the final loop from node to end user, and at present, service areas are fairly limited.  Comcast and other cable providers supply service based on hybrid fiber-coaxial (HFC) with a fiber backbone and the end user loop based on coaxial cable that currently provides bandwidths of up to 16 Mbps using the DOCSIS 1.1 standard.  Both Verizon and Comcast are promising big increases in the next year, claiming top speeds of 150 and 100 Mbps respectively.

Verizon is currently updating to the new Optical Network Terminal (ONT) hardware and cable providers are looking to roll out the DOCSIS 3.0 standard.  It remains to be seen if either of these services can make good on the promised speeds within the year.  More importantly, it also remains to be seen what the real timeframe is before widespread service availability.

Any way one looks at these numbers, hitting 40 Mbps to the end users puts internet based HDTV distribution quality into the range of the current optical disc technology.  Blu-ray disc data rates max out at 53.95 Mbps, including computational overhead, with 48.0 Mbps available for the A/V data stream while HD-DVD data rate is at a 36.55 Mbps maximum with 30.24 Mbps available for the A/V data.  Contrasted with the current highly compressed HDTV quality broadcast signal that is limited to 6 Mbps bandwidth, any IPTV service consistently able to run 40 Mbps or better would allow for streaming HD content that would rival the quality of prerecorded optical discs.

Such internet based HDTV service and quality may not be available yet, but the concerted push by technology companies and internet service providers will leave a much shorter life cycle for HD optical disc technology than SD DVD had before having to face the next upstart technology contending for mass consumer acceptance.

About the author:

Professionally, David engineers building structures. He is also a musician and audio enthusiast. David gives his perspective about loudspeakers and complex audio topics from his mechanical engineering and HAA Certified Level I training.

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Recent Forum Posts:

westcott posts on February 26, 2008 12:25
Gene is correct. The technology is only part of the limiting factor. Just ask anyone who has watched (or tried to watch) any of the Netflix on demand videos. Even in SD, they look terrible and rarely provide a seamless viewing experience.

Almost every content provider chooses quantity over quality and butchers the bandwidth to provide more services\channels that they can make more money on.

I am not optimisitic that technology advances in bandwidth are going to bring better video quality any time soon!!!
gene posts on February 25, 2008 23:02
This technology is nothing new. I worked on this about 7 years ago at my former employer Paradyne but they weren't savvy enough to market it properly and get industry acceptance with the RBOC's. They have since then been bought out and their stock hovers at $1/share with no chance of ever recouping.
Biggiesized posts on February 25, 2008 22:54
The ATSC should get smart and add 256-QAM to the standard. It'd allow double the bandwidth in the same 6 MHz.
fiosmeup posts on February 25, 2008 18:12
Verizon is offering the faster DSL service 7.1 meg for places that won't be getting fios. Fios is about TV, internet and phone bundles. I don't think they are to worry, it will help them compete against Cable internet.
Fios internet has speeds of 5-20 and 50 megs with plenty more speed to come…
Da
DavidW posts on February 25, 2008 17:18
Biggiesized, post: 380525
HDTV is limited to 6 MHz, not 6 Mbps, David.

You are correct.

It is 6 MHz per channel and not Mbps, which is the frequency bandwidth spread from the days of analog. Using 64-QAM, this is about 27 Mbps, total data bandwidth, which even without overhead, is less than either HD optical disc format currently runs data. And that is if the TV provider dedicates the entire 6MHz to a single digital program but often the providers opt to cram more in.
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