With today’s announcement that Charter Communications is trialing switched digital video (SDV) in part of its Los Angeles area system, all of the top five MSOs in the U.S. now have SDV percolating in some form.

Charter is using SDV pioneer BigBand Networks’ SDV management server and the company’s third-generation Universal edgeQAM, the BEQ 6000. Charter has approximately 420,000 customers in Southern California, and the trial includes a portion of those.

With SDV, cable operators are able to send just the digital signals that are being watched in a service group or node instead of the entire lineup of channels. Cable operators use this reclaimed bandwidth for more HD channels or other services.

Charter, the nation’s fifth-largest cable operator, said it would use SDV to expand HDTV and other programming options.

“The whole cable industry is being driven to deliver more HD content,” said Doug Ike, Charter’s VP of advanced video and applied engineering. “In the middle of 2007, Charter started aggressively deploying more HD across our entire footprint. Over the next 12 to 24 months, there will be a huge proliferation of HD content becoming available to us. Switched digital video is a mechanism that we can use to free up any bandwidth pains that may exist.”

Ike said Charter will have 40 to 50 HD linear programs, up from around 20, over the next few years.

This past summer, Cox Communications announced its first SDV deployment, with technology from BigBand, in its Northern Virginia system. Also this year, Cablevision announced the single-largest SDV deployment to date when it installed BigBand’s technology across its New York City metropolitan-area footprint.

Time Warner Cable, which had the first SDV trial in its Austin, Texas, system in 2004, has said it plans on having SDV in half of its divisions by the end of the year. Comcast currently has SDV trials in its Denver and New Jersey systems. Comcast also plans on using eQAMs from Arris and Harmonic to deliver SDV, VOD and other services over a shared infrastructure.

Since Charter has both Scientific Atlanta and Motorola systems in its headends, Ike said the company wanted to take a cautious approach to deploying SDV. The Los Angeles system uses Scientific Atlanta.

“I think the current thinking is that the Motorola solution is just now maturing to the point of deployment,” Ike said. “I think it’s a safe bet to say that Charter will be aggressively deploying switched digital video in its larger competitive markets over the next two years.”

As for using eQAMs to share SDV or VOD at the edge of a network, Ike said Charter needs to get comfortable deploying SDV before looking at the next level of technology.