Monday, May 04, 2009

Fiber Optic Speeds Come to Cable

Cablevision systems Corp. is raising the bar on broadband Internet service by breaking the 100 Mbps speed limit over Cable TV service. They announced a rollout of the new high speed Internet service starting May 11. Sign up and you can get download speeds up to 101 Mbps with upload speed of up to 15 Mbps for around $100 a month.

But just a second. Isn't Cable TV still using regular old RG-6 coaxial cable? I thought you needed fiber optic cable to get those kind of speeds.

Oh, there's a lot more bandwidth capability in copper wire that you might suspect. It comes down to how efficiently you use the capability that exists. Even common twisted pair telephone wire is capable of transporting Mbps level signals up to several miles. The latest technology for last mile delivery of business grade bandwidth is EoC or Ethernet over Copper, which is able to provide up to 45 Mbps using multiple copper pair that most businesses already have installed.

The magic behind the Cablevision advance is called DOCSIS 3.0. DOCSIS is the standard for transporting broadband data on cable television systems. The acronym stands for Data Over Cable Service Interface Specification. If you have a cable modem, it's running one of the DOCSIS standards. What this standard does is define how to create data channels that fit into standard 6 MHz TV channels so that they will pass unhindered through cable equipment. The cable operator decides how many channels it needs to set aside to support the demand for cable modems.

The latest version, just coming into service now, is DOCSIS 3.0. This upgrade specifies bonding up to 10 NTSC TV channels of 6 MHz each to provide a bandwidth of 60 MHz. MHz and Mbps are not the same. With clever modulation schemes, you can get a lot more than 1 Mbps from a 1 MHz channel. The DOCSIS 3.0 standard offers cable operators 4 channel bonding for a maximum usable speed of 152 Mbps downstream and 108 Mbps upstream. The 8 channel bonded option gives a maximum usable speed of 304 Mbps downstream. That's lots of room for growth as demand increases.

What is driving the need for 100 Mbps Internet service? It's all about the video. With that amount of bandwidth, a user can download a full-length HDTV movie in less than 10 minutes. Make no mistake about it, HD video is a snowball that is starting to roll downhill. Internet service providers that get in its way with things like slow connections and bandwidth caps are going to get rolled over as the public embraces IP TV. Satellite and Cable operators would like to insist that they be the providers of all TV content on a subscription or pay per view basis. The public is having none of it. They're going to third party providers, such as Netflix, or going directly to TV network websites to get episodes of their favorite programs that they've missed. YouTube remains a popular destination for shorter video clips, but may well become a clearinghouse for full-length programs of all types.

How far will this go? Look for other cable companies to embrace DOCSIS 3.0 and match Cablevision's 100 Mbps speeds. I'd also expect the same from Verizon's FiOS, a fiber optic technology that has plenty of bandwidth available. Those silly bandwidth caps are going to disappear at least for high-end bandwidth users. Nobody is going to pay $100 or more a month for broadband and then be told they've used up their allotment by mid-month. That means cable companies sucking it up and installing faster Internet backbones and agreements with content delivery networks as well as boosting speeds to the users.

Follow Telexplainer on Twitter