8-VSB receivers located in the regions of overlapping coverage areas would require spatial-diversity antennas if SFNs were employed. This is an expensive proposition and is impractical for hand-held receivers, lap-tops, etc. The alternative is for the 8-VSB transmitters to stagger their transmissions in times, which provides no better spectrum utilization than with disparate-frequency networks or SFNs using COFDM. Al ----- Original Message ----- From: "Albert Manfredi" <albert.e.manfredi@xxxxxxxxxx> To: <opendtv@xxxxxxxxxxxxx> Sent: Sunday, June 27, 2010 11:01 PM Subject: [opendtv] Re: Charles Rhodes on SFNs > > Craig Birkmaier wrote: > > > The distances between antenna sites for SFNs that > > use the same channel for different content can be > > significantly closer than 100 miles based on power > > levels and emission masks. > > Maybe you are saying something different from what I interpreted previously? Maybe what you're saying is that two single-market SFNs on a given frequency channel can be placed closer together than the contours of two big sticks? Meaning, the interference zone between the two Ch X coverage areas can be reduced, if coverage is provided by SFNs? > > I covered that already multiple times, and so did Doug Lung. Remember what he wrote. The SFN power density at the edges of the market cannot be any lower than what it is with the big stick, or you will simply lose viewership. So in fact, an interference zone will still exist, exactly where you cannot have one. In these congested corridors, there are no significant unpopulated areas. > > And even more importantly, what you are saying requires a dense mesh SFN. Not the Euro variety SFN. Dense mesh SFNs, aside from being costly, are iffy. They don't work well, even with DVB-T. With DVB-T2, the advantage is that the towers can be spread apart further, which negates any potential cookie cutter, sharp pattern advantage. > > So, a losing proposition all around. As the broadcasters reported to the FCC, there are no significant spectrum advantages to single-market SFNs. Ease of reception maybe, and I think that DOCRs, even with 8-VSB, should help in difficult places. > > Bert > > _________________________________________________________________ > Hotmail is redefining busy with tools for the New Busy. Get more from your inbox. > http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:WL:en-US:WM_HMP:042010_2 > > ---------------------------------------------------------------------- > 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. > ---------------------------------------------------------------------- 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.