Cringley On Bandwidth-Expanding Modulation Technology

jtappan writes: "Robert X Cringely has an article describing a new modulation technology that will allegedly allow cable modems to run 10 times as fast, and which will eventually allow existing cable networks to carry 500 HDTV channels."

Comments

Wavelets wash back

[maggard]

Great - wavelets are back again; however this time not for compression but for high-speed signaling and to avoid interference.

Cringely reports the folks are about to set their design in silicon so we'll find out then but I'm not holding out a lot of hope. On the other hand the basic theory is pretty easy to test and apparently they've convinced more then a few folks who've apparently done their due diligence.

• If the signal propagates properly
• If it can be discerned from ambient noise and other channel's interference
• If the processing delay isn't too great
• If the chipset is cheap enough
• If the upstream folks roll it out

Etc.

ps To every first year student - think carefully before pointing out why this won't work. I expect that better minds then yours have had a look already so check your numbers and facts before posting please.

Re:Wavelets wash back

[Zeinfeld]

Great - wavelets are back again; however this time not for compression but for high-speed signaling and to avoid interference.

Reading the article I think that Cringely's biggest problem is that he does not understand how long it takes to get technology from a proof of concept to a working system.

With the Web it has taken ten years and counting to get this far. Idiot pumpers like Meaker and Blodget aside, Internet time runs at 1 for one with GMT at best.

I first heard about ISDN in the 80's, ten years later people started to get ISDN phone lines. Likewise with DSL the basic ideas were floating arround in the early 90s but are still not fully baked for deployment.

It does not seem unreasonable that people will be rolling out much faster cable networks in (say) 2010 or so. I don't think it is going to happen on any larg scale before then however. The DOCSIS standard has only just been developed and it will take at least 3 years for any radical redesign to make it into a spec and another 2 to get into production, then there will be the inevitable delay as results from trial deployments are assesed and so on.

What cringely and co miss is that athough the majority of the cost of a fully deployed system is at the consumer end s not where the killer costs lie. To roll out broadband access in a town you first have to buy lots of gear that typically comes with five or six figure price tags. You have to buy that gear whether one person buys service or ten thousand. The client end costs are not so much of a problem because each customer pays a subscription.

That is why the cable companies partnered with the losers @Home to deploy broadband. The cable cos were not prepared to gamble their capital on the success of broadband. @home was. Of course the minute that there was proof of the business plan @home became surplus to requirements

So yeah, wavelets, whatever, but at the moment the bandwidth in the last mile is not the bottleneck. Nor is the bottleneck in any of the pipes. There were four companies that deployed fibre backbones over the last five years, each of which has more capacity than the country could use before 2015. It is the switching capacity that is expensive and that comes down to pricey silicon and probably always will. If you have computing technology of power X you end up with switching nodes that require processing power of many, many X.

I don�t see how this helps anything

[G00F]

Camblemodems are able to run much faster than they currently do. They are told to run so slow for a few reasons.

1. Cost them money to get the big pipe for the users
2. Make you play well with others
3. They tailor the service for people who would not be willing to pay more for more bandwith.
4. They have a monopoly, so they can do what ever they want with very low risk of losing you to compitition.

I've downloaded 700k a second, and uploaded over 500k a second on the old lancity cablemodems in fremont cali years ago. Sicne then they have pushed cablemodems that they can control the speeds on. And they do, they slow them down hugely.

What's The Point (for cable modems)?

[John_Booty]

It's nice that ISP's could provide 100x faster service, but they're already capping the bandwidth they DO provide. I think this technology is solving a problem that simply doesn't exist in the cable ISP game.

That's not to say this tech doesn't have other, awesome applications. But I don't think cable companies are exactly going to be lining up to roll this out. :-)

Hey Taco

[SubtleNuance]

Why dont you can Katz and give Cringley a job?

I wonder what the ratio of katz-ignoring-slashdotters vs cringley-article-hits is.

Anyone remember Transmeta?

[timholman]

After reading the article, I checked out Rainmaker's site. These guys have a theory, some patents, and some simulations. What they don't seem to have is any working hardware that proves this 10X bandwidth increase can actually be achieved in residential cable systems.

Does this remind anyone of Transmeta, who promised processors with a fraction of the power consumption at higher speeds? Everybody loved them when all they had was a press release. The actual product didn't work as advertised, and now they've faded away.

If it sounds too good to be true, it probably is. 10X uber-bandwidth schemes sound suspiciously like 10X uber-compression schemes. I'll reserve my enthusiasm when I see working hardware.

I don't mean to sound snide but...

[JoeShmoe]

...if Slashdot is going to be posting nearly every single article that Cringley writes (five times this past month) shouldn't he basically get his own Slashbox or topic?

I mean, I know Slashdot is a user-submission site but of given Cringley's anti-Microsoft pro-techi slate I think it's a given that someone's going to be submitting everything he writes. Shouldn't Slashdot be somewhat discerning in which articles they post? If I wanted to read everything he wrote I would just bookmark his site (as I have done). To see it posted on Slashdot every week seems, I'm sorry, -1 Redundant.

How about we just link this and be done with it?

http://www.pbs.org/cringely/pulpit/

- JoeShmoe

.

Modems are maxed out

[BeBoxer]

Modems are basically completely maxed out given the contstraints that they operate under. Your math assumes getting 10 bits per hertz (realistic) and getting 56KHz (unrealistic). The phone system is designed to carry voices, not binary data. As a result, it's optimized for the frequency range of the human voice, which only extends up to the 3-4KHz range. In fact, unless you live in the sticks and are calling your neighbor, it is almost for certain that your call is being carried digitally. If so, it's being sampled at 8Hz meaning that due to Nyquist you can't send any frequency higher than 4KHz thru the phone system. Period. You'll notice that if you figure out the bits/hertz that a 56K modem sends, its as good (~8 bits upstream) or better (~13 bits downstream) than what this company is claiming to get.

Basically, they have a system which works as well as a phone modem. Not too suprising really, I suspect that the fundamental limitations on signal and noise are pretty similar for the two different kinds of copper wire run to your house.

Re:Great!

[Mr Z]

Actually, Cringley gets it wrong. Modulation happens at the PHY layer, not the LINK layer. So either this is a crock of s**t as big as what ZeoSync was stirring, or Cringley has his head up his arse. Notice that that's not an exclusive-or.... both could be true.

This link pretty much covers it. I'll quote the most relevant bits:

1. The Physical Layer describes the physical properties of the various communications media, as well as the electrical properties and interpretation of the exchanged signals. Ex: this layer defines the size of Ethernet coaxial cable, the type of BNC connector used, and the termination method.
2. The Data Link Layer describes the logical organization of data bits transmitted on a particular medium. Ex: this layer defines the framing, addressing and checksumming of Ethernet packets.

So, in other words, the Physical layer is where signaling happens. (This is where QAM and this wavelet snakeoil are relevant.) The Link layer is where PPP, SLIP, and Ethernet Packet encapsulation happen. (Not Ethernet signaling, just the 802.3-or-whatever framing spec.)

--Joe