Cable Tech

ADSL, Take 2+

ATLANTA -- Supercomm 2003 -- Chip makers at Supercomm this week showed off the latest standard enhancements to asymmetric digital subscriber line (ADSL), emphasizing the technology's ability to carry video and therefore rival cable services.

Ratified by the International Telecommunication Union (ITU) in February, ADSL2+ boosts the speed and range of existing ADSL lines, with on-paper potential for 25 Mbit/s at distances of about 6,000 feet -- real performance varies depending on the surrounding environment [ed. note: and dealer preparation charges, local taxes, and licensing fees]. The technology would also extend the reach of 384-kbit/s ADSL service to about 16,000 feet.

Better speed and reach always sound good, but the real target is video. "With enough video compression, you can have up to three video streams running on ADSL2+," says Angelo Stephano, vice president of marketing for GlobespanVirata Inc. (Nasdaq: GSPN).

Video would give ADSL an entry in the fabled (and by now clichéd) "triple play" of voice, data, and video services (see Telcos Tackle Triple Play ). More important, it would be a counterbalance to cable, which has gotten its own triple play going by offering voice services.

"We're seeing genuine interest [in ADSL2+] because the cable guys are getting penetration in voice," says David Benini, DSL marketing manager for Aware Inc., a company that develops technology for chip makers.

Very high speed DSL (VDSL) was supposed to help boost DSL video, but ADSL has been pumped up enough to become a viable alternative.

"It will take time for VDSL to be installed and deployed, because it requires a lot of different infrastructure," Stephano says. VDSL isn't completely ratified, due in part to a tiff over line-code schemes (see High Noon Arrives in VDSL Battle). Moreover, the VDSL standard isn't going to support the long reaches that ADSL can hit, and VDSL equipment will be relatively expensive for some time.

Here's a rundown of ADSL's recent makeover:

  • ADSL2: Not as racy as it might sound, this provides some power savings and performance enhancements, and a bit of speed. Maximum downstream speed is increased to 10 or 12 Mbit/s, up from 8 Mbit/s. Ratified by the ITU last October.
  • ADSL2+: Doubles the available spectrum for ADSL, allowing downstream transmission to use frequencies up to 2.2 MHz. The result is the 25-Mbit/s speed mentioned above.
  • ReachExtended ADSL: Also called RE-ADSL or ADSL Annex L, it allows ADSL to travel more than 20,000 feet at 384 kbit/s. DSL speeds decline the farther you are from the central office, so previous 20,000-foot service would deliver speeds of just about zero.

RE-ADSL is on the verge of ratification; the ITU has frozen the spec and is likely to complete it in October, Benini says.

The kicker is that all three functions can run on the same chip. Board makers only have to produce one line card, and the equipment operators can decide which combination of these new powers to wield.

For North America, equipment using ADSL2 and ADSL2+ should arrive towards the end of the year, but some of the technology is already being deployed in other parts of the world.

For example, chips from Centillium Communications Inc. (Nasdaq: CTLM) are already being used for 12-Mbit/s service in Japan, "and we're just about to roll the 24-Mbit/s services," says Alex Aali, senior marketing manager for Centillium. "Japan has been more aggressive in rolling out high-speed services than the rest of the world, so some of these technologies will be appearing there first."

There's no ADSL3 on the horizon yet, Benini says. But the next step might be to increase the density of DSL lines in a bundle. He says researchers at Stanford University are working on Dynamic Spectral Management, "which allows you to dynamically manage the different lines in a bundle, because they crosstalk with each other, and they interfere with each other."

Some vendors are also considering quadrupling the downstream spectrum to produce 50-Mbit/s service, sort of an "ADSL2-plus-plus," Aali says.

— Craig Matsumoto, Senior Editor, Light Reading
BobbyMax 12/4/2012 | 11:57:31 PM
re: ADSL, Take 2+ It is well known that video services can be provided over DSL. But the DSL penetration is not strong enough for RBOCS to provide this service ecnomically.

The other point is providers of video services should not be allowed to provide pornographic services. Some providers or middlemen want to capitalize on the immense appetite for sexual materials.

I think that MMDS should be further examined to provide video services. This would be much more cost effective.
gea 12/4/2012 | 11:57:29 PM
re: ADSL, Take 2+ BobyMax wrote...

"The other point is providers of video services should not be allowed to provide pornographic services. Some providers or middlemen want to capitalize on the immense appetite for sexual materials."

Why not? It would seem you want to impose your morality on the rest of the world. And seeing how you are willing to slander and libel anybody at the drop of a hat without providing any references, I would suggest that your own morality is worth about 5 cents, if that.
SCPJ24 12/4/2012 | 11:57:28 PM
re: ADSL, Take 2+
I'm not an expert on the different technologies, but as a user -- I have a cable + modem and a cell phone. I just can't see how DSL makes any sense. Hell, even my nephews have cell phones.

Travel anywhere in the world and the only place that relies on land lines is the US. The only thing I use my land line for is local calls and incoming calls. If someone had a box where I could plug my cell phone into and it would disperse the signal to the different phones in my house, I might not even need a land line.

The effort seems awful large for a limited market that has little long term future.
digerato 12/4/2012 | 11:57:13 PM
re: ADSL, Take 2+ When I find myself agreeing with Bobby "Mad" Max, it gives me pause for thought. But fortunately, I agree with him that video is not feasible for a totally different reason: there just isn't that much money in video delivery.

Yes, I've read the breathless prose about the much vaunted RBOC "triple play", but nowhere does anyone say "Gee, how much money would we *actually* make with this service?"

*Total* cable advertising for 2002 is estimated to be $11Bn. Local cable advertising (which is what SBC would be most successful) is estimated to be $3.5Bn for 2002. Subscription revenues from consumers are a mere fraction of these numbers. For comparison, SBC's first quarter 2002 revenues were $10.5Bn.

So, why is video such a good idea?


rjmcmahon 12/4/2012 | 11:57:07 PM
re: ADSL, Take 2+ So, why is video such a good idea?

Imagine a person was tasked, by God, to both teach his oldest how to build a differential transmission and his youngest how to perform a quadruple bypass. God tells this person, "You'll have a need for these one day and it's best that you pass on these skills."

But unfortunately God also says, "Since mankind is merely human, and has much to learn about existence, I will have to give you a disability which you have no choice but to accept." God, being gracious, does give us some options to choose between -- blindness or deafness -- we choose.

Our society has chosen blindness. An irrational choice, in my opinion. So, I say we defy our disability and build the prosthesis which will help us perform our tasks. Let's give ourselves the vision we so desperately need and reverse our decision. And then, maybe, we will become a better people, able to teach and serve those around us.
diag_eng 12/4/2012 | 11:56:46 PM
re: ADSL, Take 2+ It's not that video is a good idea (or not), but rather it is becoming a necessary evil in the "Triple Play" product. The RBOC's already have the voice and data - they lack video. The dividing line of voice, video, and data is subtly disappearing with emergence of VoIP. When the line is "gone", and voice and data are bits, the cost of delivering these services decreases significantly - hence profits rise and the cost to the consumer is less. How will the RBOC's compete? They won't be able to do so.

For instance, Comcast (#1 MSO w/20M homes passed) will be aggressively marketing VoIP over the next 6-18 months. The cable industry is a copy cat industry. The other MSO's will copy what Comcast does, more or less. The RBOCs stand to lose substantial revenue, both voice and data.

Personally, I'm a "triple play" customer of Comcast (previously ATT Broadband). I switched in 2000 for a cost savings of roughly $20/month. What's going to happen when the #1 MSO, with 20 million homes passed, aggressively pursues the RBOC's voice company.

IMO, in the evolution of communications broadband will kill copper, and someday, satellite/wireless will kill broadband.

You should know better than to aggree with "Mad Maxx". :)

I agree with him that video is not feasible for a totally different reason: there just isn't that much money in video delivery.

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