SAN FRANCISCO -- The TV of Tomorrow Show -- Comcast Corp. (Nasdaq: CMCSA, CMCSK) and other MSOs that are gearing up for big Enhanced TV Binary Interchange Format (EBIF) deployments this year are going through a "pipe cleaning" exercise to ensure that the integrity of those apps are maintained as they snake up and down the cable network.

One big technical challenge for EBIF is ensuring that applications don't get corrupted or dropped altogether as they travel through the networks and pierce through processors, multiplexors, and other devices that apps will encounter as they travel inside video transport streams.

"At every link there's the opportunity that something can happen to that transport stream. There are opportunities for things to get dropped," said Steve Reynolds, the SVP of premises technology at Comcast, during a keynote session here on Thursday.

Reynolds said the pipe cleaning effort got underway last year and originated with Canoe Ventures LLC , the cross-MSO advanced advertising JV that will use EBIF to power interactive, "request for information" (RFI) ads that allow viewers to get coupons or product samples directly from advertisers. Canoe expects to launch the campaign this spring to a subset of Canoe member systems. Canoe's members already have between 20 million to 25 million boxes EBIF-enabled. (See Cable's Canoe Heads for Scalable Waters .)

This Roto-Rootering aims to clear out the virtual gunk on the cable networks and clear the way for EBIF apps to move freely from their origination point down to the set-top, and then back upstream again when customers respond by clicking the remote control.

One big item on that list is ensuring that there's enough bandwidth freed up for the EBIF apps themselves. Reynolds estimates that the Canoe RFI app will require about 100 kbit/s. More complicated EBIF apps on the roadmap, such as trivia and polling questions, might need 150 kbit/s. Even more advanced apps could require up to 400 kbit/s, he said. No matter the amount, operators will need to be allocated the necessary bandwidth on every network that's transporting an EBIF application.

Canoe has not said how many networks will participate in the initial RFI deployment or how many EBIF ads it intends to deliver in the early going. But, in this scenario, too much of a good thing has the potential to cause a bandwidth crunch.

However, Reynolds isn't overly concerned about the bandwidth implications of EBIF. "I fully expect over the course of the next year... there will be a lot of creative problem solving attached to that," he said. By way of example, he noted that cable operators now use variable bit rate (VBR) technology to multiplex data and fit more programming into a 6MHz channel slot, so the industry should have little trouble freeing up the necessary headroom for much smaller EBIF apps.

Bandwidth questions aside, Reynolds said recent trials are demonstrating that the "commercialization profile" for EBIF and Canoe's EBIF "templates" are behaving well across myriad MSO headend and set-top environments. The idea there is to ensure that there's interoperability among different cable systems and EBIF set-top clients, something that was considered a big worry about a year ago. (See Canoe Preps ITV Ad 'Template' and TV Apps Teams Face Cable Conundrum.)

— Jeff Baumgartner, Site Editor, Light Reading Cable