The momentum behind Full Duplex DOCSIS is growing. Originally announced as an exploratory project in February, the technology moved into full specification development in August, and now CableLabs is forecasting that the first Full Duplex trials will take place in about 12 months. (See CableLabs Makes Symmetrical Multi-Gig Push and Full Duplex Is a Go; Cable Aims for 10 Gig.)

Speaking at Light Reading's The Future of Cable Business Services event in New York last week, CableLabs Chief Strategy Officer Ike Elliott put a timeline on Full Duplex's progress, suggesting that the technology for coaxial networks could strengthen the cable industry's position in the business services market in the not-too-distant future. Full Duplex, which promises symmetrical speeds as high as 10 Gbit/s in theory, and more likely 5 Gbit/s in the upstream in reality, could allow cable operators to compete for more high-bandwidth commercial contracts. The technology enables both upstream and downstream traffic to operate in the same spectrum at the same time, thereby doubling spectrum efficiency and increasing overall capacity.

"[Full Duplex is] something that's in the labs right now," said Elliot. "We're working with the vendor community in defining specifications on it, and we really expect to see some trials on that within about a year."

However, Elliot cautioned that Full Duplex won't be rolled out all at once by cable operators.

"It requires getting fiber all the way to the last active [component] in the network," noted Elliot, adding that, "There's a big infrastructure investment to make... so [Full Duplex is] not going to be available across a broad footprint on day one."

There are other issues with Full Duplex too. Many experts believe that the cable industry's reliance on DOCSIS is hampering success in the commercial market. Both Andrew Smith, chief architect for cable MSO networks at Juniper Networks Inc. (NYSE: JNPR), and Lucas Binder, consultant at Interactive Broadband Consulting Group LLC (IBB) , argued at the event that only all-fiber networks can adequately serve the needs of large enterprises. They also contended that by foregoing all-fiber connections, cable operators are conditioning business customers to expect a residential-class product. In addition to short-term consequences, that mindset could create a long-term perception problem. (See Experts: DOCSIS Won't Cut It in the Enterprise.)

For more on the commercial services market, visit the dedicated Cable Business Services channel here at Light Reading.

From a technical perspective, there are concerns as well. One potential problem with relying on DOCSIS in the future is that cable operators will be requiring a lot more from the nodes at the edges of their networks. As Light Reading's Components Editor Brian Santo has reported, cable companies are hoping to implement three technology upgrades at once that would put unprecedented new demands on cable nodes. They'd like to move to a Node+0 architecture, expand to 1.2GHz of spectrum and deploy Remote Phy. All of these upgrades require more power in the node, and today's products simply can't support the power requirements for all three. (See Cable Nodes Becoming a Choke Point.)

As cable operators move forward, they also hope to deliver more services off their network nodes, including residential, commercial and wireless offerings. That desire could complicate infrastructure decisions for service providers, including whether to pursue Full Duplex DOCSIS.

"From a strategic point of view," said IBB consultant Dan Dodson recently, "if you can offer a lot of different services to a lot of different customers, then you start looking more like Google and less like Comcast."

The question is: Will Full Duplex make sense in that environment, or will it add too much complexity to the equation? Will Full Duplex DOCSIS be a logical solution for a broad set of cable deployments, or will it be a niche technology as cable expands its horizons?

— Mari Silbey, Senior Editor, Cable/Video, Light Reading