Slashdot Mirror
Comcast CEO Shows Off Superfast Modem
Gary writes "Comcast CEO dazzled cable industry audience by showcasing a super quick modem, using a technology called DOCSIS 3.0. It was developed by the cable industry's research arm, Cable Television Laboratories. It bonds together four cable lines but is capable of allowing much more capacity enabling a data download speed of 150 megabits per second, or roughly 25 times faster than today's standard cable modems. 'The new cable technology is crucial because the industry is competing with a speedy new offering called FiOS, a TV and Internet service that Verizon Communications Inc. is selling over a new fiber-optic network. The top speed currently available through FiOS is 50 megabits per second, but the network already is capable of providing 100 mbps, and the fiber lines offer nearly unlimited potential.'"
They're competing with FiOS? The connection promised by every phone company 10 years ago that was never delivered despite being given money by the government to do so? The connection technology just now being rolled out by ONE phone company in a handful of cities?
That's competition?
More information can be found at:a tions30.htmls 30_080706.html0 .html
1. Specifications: http://www.cablemodem.com/specifications/specific
2. Press release: http://www.cablelabs.com/news/pr/2006/06_pr_docsi
3. Ars Technica article: http://arstechnica.com/news.ars/post/20060808-745
instead, multiple upstream or downstream channels are used. The real factor in achieving these speeds depends on what modulation type your cable op decides to configure on the CMTS. In a perfect world everything is 256-QAM/128-QAM, but you will often see 32-QAM implimented because the end to end cabling can't support the rf throughput required for higher bandwidth modulation types. The wiki article on DOCSIS is a good place to start for more information.
The description stating that it "It bonds together four cable lines" is a horrible description of what is likely going on here.
Cable/tv channels are 6 MHz wide. On a typical cable system you can use 256QAM to encode digital data for transmission. In 6 MHz you can get about 39 Mbps. If you bond four channels together (24 MHz) that's 156 Mbps using 256QAM.
So what it sounds like is DOCSIS 3 supports channel bonding or perhaps simply a very wide channel.
The "four cable lines" has nothing to do with how much physical coax comes to your house. On paper an all digital 750 MHz plant could deliver on the order of 4.5 Gbps. But having 70 channels of analog really cuts into that.
They mean 4 channels/frequencies, not 4 cables. 40Mbps over a single channel is normal, so 160Mbps over 4 channels makes sense. Channel bonding is very normal to speed things up, they use it in 802.11n and most newer cellular data transmission protocols. I don't see why this should make slashdot. It is nothing new and nothing revolutionary.
It only takes one man to change the Wisdom of the Crowd to Tyranny of the Masses.
The article description isn't very accurate - when they say "lines", they really mean "channels". Cable modems now operating on a single 6mhz "channel" on the cable line. DOCSIS3 lets the modem "bond" several channels to increase bandwidth. Only one physical cable is still required. This takes away from the # of channels available for TV, but as they move more of the channels off analog to digital (which fit multiple channels in a single 6mhz band) frequency space is being freed.
Just having a faster modem will not result in faster downloads. It is like fixing a huge 150" tap to a 1" pipe. Unless the internet backbone, the servers, the routers, switches, bridges increase their capacities we are not going to see an across the board increase in download and upload speeds. We might see some fast on demand IP based TV solution provided by the ISP and stuff like that. But slashdot.org is probably going to load at the same speed it is currently loading and your email attachments are going to take as much to upload as it is currently taking.
"Be the change you wish to see in the world" - M. K. Gandhi
It is not clear whether the "it" referred to is the modem or the "technology called DOCSIS 3.0". In either case, the quoted information is not true.
DOCSIS 3.0 is a suite of specifications that represents the newest release of the DOCSIS specifications that have been around for nearly a decade now. CableLabs (the usual name for "Cable Television Laboratories, Inc.") managed the process of creating the specs, and performed the actual publication, but the specs themselves were developed in almost entirely by equipment manufacturers, with input from interested (mostly large) cable operators.
Similarly, the modem that was demonstrated was built not by CableLabs but by one of those equipment manufacturers (ARRIS, for whom I work, although I have no direct association with the group that builds the DOCSIS 3.0 modem; I was a contributor to the DOCSIS 3.0 specs).
The complete sleep-inducing suite of specs may be downloaded from www.cablelabs.com.
It's a standard. I remember being one of the people stuck ... er, tasked with, reviewing the first version. It was a painful read, but definately showed that there was "something new in the air." A lot of surprising things were taken into account, especially in a time frame where DSL was just starting to kick cable's ass. I'm curious to see what the new standard includes.
Bark less. Wag more.
I use cable 24/7 and I've never experienced this. And believe me, if my latency were spiking from 40ms to 30000ms while I were gaming, or even checking webpages, I'd fucking notice it. My thoughts are cable in your area just flat out sucks. In mine, it's absolutely divine. DSL, on the other hand, is out for about 45 minutes to an hour every 2 or 3 days for my neighbors on either side of me. Pure silliness.
Hold on, if its 150Mbps - and your running on Ethernet (might as well forget USB)
your gonna need gigabit networking, at least connected to the modem, otherwise your gonna lose 1/3 of your connecting because the Ethernet cant keep up
Not forgetting gigabit kit is still quite expensive (routers, switches, cat6 cabling - if you must use it)
This article has one key line that just makes me want to scream.
This is NOT 25 times faster than current standard cablemodems. It may be 25 times faster than Comcast currently OFFERS, but that is a significant difference.
One of the reasons uncapping modems worked as well as it did is because DOCSIS 1.1 and 2.0 are both capable of 45Mbit/sec downstream. There are current services (Disclaimer: I work for Cablevision, where one of these is offered) that are offering 30Mbit/sec download speeds - and getting them. (I personally have topped out at 29Mbit/sec.) There are other technologies than DOCSIS out there that are currently implemented which are easily capable of 100Mbit/sec.
There's absolutely nothing to get excited about with this. If anything, I admit to being puzzled as to why they weren't managing 180Mbit/sec on a modem with 4 bonded channels - 20Mbit/sec is a bit much to be writing off to overhead.
DOCSIS 3.0 is a solid step forward, but this is not the next greatest thing. There are comparative technologies available right now that would require minimal upgrades, if any. And the guy at Time Warner's right, what can't you do with 30Mbit/sec that you can with 100Mbps?
You thought that this sig was what you think that I thought you wanted me to think. I think.
I live in Chicago. We here (including the suburbs) are about as densely packed as Japan is. Japan gets 30-50 Mbps synchronous (actual speeds, not advertised peak speeds) for about $20-30 a month. In Chicago, we can get 8M/768k (advertised; actual will dip up and down depending on how many people in your neighbourhood are also online) for about $80 a month. What the fuck.
Also, $200-300 per month for just 1.5M synchronous (T1) is a fucking ripoff. We already paid the telcos billions of dollars to fucking build us a good Internet infrastructure, but instead we've got overpriced shit and overpaid telco execs. We don't even have competition that would squash this, and the government doesn't seem to care that they were ripped off of several billion dollars by these sleazy telcos.
'Yes, firefox is indeed greater than women. Can women block pops up for you? No. Can Firefox show you naked women? Yes.'
Most Cable providers are still running at DOCSIS 1.x and are planning a rollout to 2.x over YEARS of deployment.
Your bandwidth is constrained by your cable ISP's bandwidth to their Tier2 or Tier1 provider and your subscription plan.
My modem was capable of a theoretical 40Mb/s+ 5 years ago. I doubt comcast will be offering ANY service in the next 5 years that max out the capability of my DOCSIS 1.x modem.
Upload isn't just for p2p.
Ever since I got a PS3, I've been video chatting with a friend of mine in England, a friend in the next city over and my family on the opposite coast. It seems the main limiting factor in our video chat quality is the upload rate of the person sending video. As a result, I get much better video from my friend in England (who has a rather large upload rate) then my friend in the next city over (who has the slowest upload rate...and is also using comcast).
Better upload rates are definately of interest.
-tom