Cisco Pushes DOCSIS 3.0 Past 1.5 Gig [Multichannel News]
Cisco demonstrated another milestone in the DOCSIS 3.0 standard at the CableLabs Winter Conference recently. CableLabs is the research and development consortium for the cable industry which maintains the DOCSIS cable modem standard.
Using 48 bonded channels, Cisco was able to achieve a nearly 1.6 Gbps downstream broadband speed and 300 Mbps upstream at the conference. The demonstration was achieved with Cisco equipment that can bond up to 72 downstream and 60 upstream channels.
While we're still a number of years away from seeing these kind of speeds made available commercially, they're yet another testament to the scalability of DOCSIS 3.0 when it comes to delivering the fastest broadband speeds today and tomorrow.
Thank you.
That was very informative.
Posted by: Paul Templeton | Friday, March 25, 2011 at 01:57 AM
Depends on the system, old/small systems may only be 450Mhz. The newest/highest capacity cable plants are 1Ghz (1000Mhz) and 1.2GHz is a possible future technology.
An analog tv channel takes 6Mhz of that line so theoretically you could see anywhere from 75 to 166 raw analog video channels.
Each one of those 6Mhz analog channels can carry 6-10 SD digital video channels or 3-5 HD channels depending on the compression technology available.
A 6Mhz channel could also carry a 38Megabit docsis internet downstream channel. Upstream is always harder to do, so that 6Mhz upstream channel would provide at best 27Megabit upstream.
DOCSIS 3 brings channel bonding into play with the same raw numbers for each channel. So that cisco test at max capacity (72 Down, 60 Up) would max out at 2736 Megabit (2.7Gigabit) down and 1620 Megabit (1.6Gigabit) up and would utilize 800Mhz of bandwidth, leaving 200Mhz for video on the biggest cable plants deployed today.
These are all best case numbers, line loss, damage to the coax and radio interference would decrease the number of usable 6Mhz channels.
http://en.wikipedia.org/wiki/North_American_cable_television_frequencies and http://en.wikipedia.org/wiki/DOCSIS provide the details behind these numbers.
Posted by: Larry | Thursday, March 24, 2011 at 10:50 PM
This may be a dumb question but how many channels can a single coaxial cable carry?
Posted by: Paul Templeton | Wednesday, March 23, 2011 at 05:33 PM