John Shutt wrote: > Since Triveni's suggested data model included using > a cell phone modem connected to the laptop as a back > channel to request information, everyone questioned > the wisdom or the necessity of having the DTV forward > channel at all. This is certainly a good point. I think a lot of confusion exists because people talk about "back channel," implying that the broadcast connection gives you the downstream link, and some sort of one-way uplink provides the other half. A common and annoying misconception. Annoying because it's so commonly used by those who profit from mindless hype. "All you need is a backchannel," they say, as if somehow they were making that part simple. In fact, what you need for any sort of interactivity is a completely separate, two-way Internet acess connection. A connection to an ISP, pure and simple. Completely independent of the broadcast channel. For the first part of the article, the carousel service to firehouses, the broadcast service could make sense. For any sort of interactive service and mobility, you'd need a different link for that in any event, so obviously a high spectral efficiency broadcast-only channel is not the right answer. Bert ---------------------------------------------------------------------- You can UNSUBSCRIBE from the OpenDTV list in two ways: - Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org - By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word unsubscribe in the subject line.