On Jun 28, 2013, at 9:36 PM, "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx> wrote: > Trying again. My last was confusing two topics. > > If you use a tall TV tower for two-way Internet service in the boonies, this > could help for a few households. As a two-way service, anything that is IP > multicast, for those rare occasions, would indeed seem similar to broadcast. > Except for the fact that if no one is listening (i.e. no one within reach of > that tower "joined" the multicast group), then the content would not be > transmitted OTA at all. > > The main point being, the number of households served by a 6 MHz channel is > going to be rather limited, for two-way service at say 1.5 Mb/s per household. Yup. > >> Second, why 6 MHz channels? We can achieve much higher levels of spectral >> efficiency with wider channels. > > Yes, but that's a small effect. > > Satellites can aim their beams, for two-way service. To do that with OTA > would require a different system. Not just using TV broadcast transmitters > for the downlink of two-way service. Yes, even in rural areas you would need a cellular approach to deliver a meaningful 2-way data service. The main difference from urban areas would be the density of the mesh, and the height of towers in low density areas. > At least we agree that in congested areas, you would go to a cellular scheme. Agreed. Regards Craig ---------------------------------------------------------------------- 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.