The five-part flow of an interactive application

Your EBIF app is built. Now what? For purposes of illustration, let's say it's a bound app, like a request for information to receive a coupon for a consumer product, or, a way to vote a candidate off a reality show, using the TV remote.

It's now time to tuck that application into the outbound video feed, for distribution to subscribing homes. How many subscribing homes? By year-end 2010, the footprint of subscribing homes, capable of displaying EBIF apps, is expected to be 25 million, or, more than half of the total potential footprint of digital cable homes. It's an unprecedented level of reach, from a cross-MSO perspective.

The application is then multiplexed into the outbound data stream of the correlating video, using a data carousel. Destination: The millions of U.S. set-top boxes equipped to "see" the incoming app, and render it on the screen. Specifically, the EBIF app becomes an "enhanced virtual service," scheduled into the network's trafficking system to ride side-car with the MPEG transport stream, as additional and specialized packet IDs, or PIDs.

The "deliver" function is complete when the EBIF application is accepted as authorized by the integrated receiver/decoder (IRD) at the cable headend, and passed along over the MSO's hybrid fiber-coax (HFC) plant to digital set-tops.