Video services

Who Makes What: Switched Digital Video

Driven by widespread deployments by operators such as Time Warner Cable Inc. (NYSE: TWC) and Cablevision Systems Corp. (NYSE: CVC), switched digital video (SDV) has emerged as one key tool to help cable operators manage their networks more efficiently, freeing up precious spectrum for more high-definition television (HDTV) and video-on-demand (VOD) content.

Soon, more cable operators will also use this newfound headroom for Docsis 3.0, a CableLabs platform that uses channel bonding techniques to delivered shared Internet speeds in excess of 100 Mbit/s. (See Comcast Enters the Wideband Era and Modems, CMTSs Break Docsis 3.0 Barrier .)

As designed, SDV allows operators to switch, rather than broadcast, some channels to individual service groups. A service group is typically made up of 250 or more set-top tuners off a given node. Channels selected for a "switched tier" are delivered via a multicast stream only when a customer in a service group selects them for viewing. As one example, Cablevision is using SDV to deliver "in-language" (foreign language) programming tiers and for an expanded menu of HD content.

Down the road, perhaps as much as five years from now, operators are expected to migrate to "unicast" SDV, enabling individual streams to be delivered to individual subscribers and opening the door to more advanced, more targeted, advertising.

For this report, we're taking a look at the major elements of the SDV architecture (the control plane, edge QAMs, and a new breed of "tuning adapters"), and their primary suppliers. We'll also provide a list of cable deployment activity and explain how switched digital video is expected to take evolutionary steps from today's multicast environments, to "virtual infinite linear," and, eventually, all the way to SDV unicast.

As with previous Who Makes What reports, this article proposes a taxonomy, lists vendors, and invites readers to suggest improvements, point out omissions, and generally lend a hand in building a comprehensive view of what is going on in terms of products and vendors.

The contents of this report is as follows:

  • Page 2: The Control Plane

  • Page 3: Rate Clampers & Edge QAMs

  • Page 4: Who’s Doing What?

    — Jeff Baumgartner, Site Editor, Cable Digital News

    Page 2: The Control Plane

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