EchoStar Communications Corp. and DirecTV Inc. will be upfront about how much set-top hard drive space customers will have to give up in order to enjoy forthcoming subscription video-on-demand (SVOD) services offered via satellite.

That full disclosure is important because DBS architecture isn't capable of offering two-way VOD over a network like cable does, but is reliant on a fixed amount of hard drive storage to offer its version of video-on-demand.

In the case of DirecTV's upcoming SVOD trial with Starz Encore Media Group, consumers who "opt in" for the service will have to give up about 10 of the 35 hours of storage available on their DirecTV/TiVo receivers, noted Greg DePrez, vice president of SVOD for Starz Encore. DePrez spoke during a National Association of Minorities in Communications (NAMIC)-sponsored event held yesterday in Denver called "Are you OD'd on OD (on-demand)?"

That six-month trial, expected to kick off "very soon," will be available to DirecTV Starz Super Pak subscribers who also own DirecTV receivers with TiVo-based on-board personal video recording functionality. Those who opt in for the free trial will get access to five SVOD titles that will be refreshed on a weekly basis. Those titles are expected to absorb about 28 percent of the hard drive's 35-hour capacity. DirecTV will download the content to receivers during off peak hours.

DePrez added that those trial customers would also be able to "opt out" as well, and that SVOD content would never copy over shows that subscribers record on their own.

EchoStar, which offers a DishPVR box, is also looking at SVOD as a future service, said Dave Kummer, EchoStar's senior vice president of engineering and systems. Like DirecTV, EchoStar's version also won't push SVOD content to a receiver's hard drive unless a subscriber asks for it, he said.

Kummer said running out of storage capacity for satellite-based on-demand services won't present much of a problem for DBS, as hard drive technology continues to ride a curve of denser and cheaper technology. EchoStar's most massive DishPVR model so far houses a 120 gigabyte hard drive, enough to store about 120 hours of video at its lowest resolution setting.