Craig Birkmaier wrote: >> The multiplexes they have now are good for 15.6 Mb/s or so. >> If they go to 64-QAM, they will be able to increase that to >> 22 Mb/s, assuming they want to go with the SFN idea (still >> 2/3 FEC, but reducing the GI to 1/8). > > These numbers are not correct. The 16QAM multiplexes deliver > 18 Mbps and the 64QAM multiplexes deliver 24 Mbps: Possibly for 16-QAM, if the existing 16-QAM multiplexes use only a 1/32 GI, and 3/4 FEC. This could indeed be how these 16-QAM multiplexes are set up in the UK. But clearly not for 64-QAM, *if* they intend to use SFNs. The 24.13 Mb/s is only available with /32 GI, when 2/3 code FEC is used. It would be very hard to deploy SFNs with only a 1/32 GI. The towers would have to be no more than about 4 miles apart all told. When SFNs are deployed in other countries, the GI is increased to 1/8. With the FEC set to 2/3, as it is for 64-QAM in Freeview, a GI of 1/8 results in 22.12 Mb/s. This site: http://www.ukfree.tv/fullstory.php?storyid=1107051058 explicitly mentions the FEC code used in each mode. It does not mention going to SFNs for 64-QAM. So that's the missing piece. > These numbers will increase when the system converts to 8K > carriers and higher power levels. Says who? > You can be certain that everything will convert to H.264. That's the second migration I was talking about. All existing receivers would need to be replaced to provide HDTV over Freeview without adding spectrum. 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.