I don't think you are understanding, so I'll reiterate.
OTA 8VSB modulated signals can provide up to 19.Mbps of data on each RF channel. High quality video signals can be transmitted this way, typically with a single video stream.
256QAM Modulated RF signals can carry up to 38.4Mbps of data, which can hold two OTA stations without modifying or degrading the signals in any way. Cox is carrying only two OTA signals on the QAM so that they can provide the retransmissions of local stations with no degradation at their full bandwidth.
The local stations are REDUCING the maximum throughput of 19.8Mbp down to lower levels in order to add additional services (weather, etc), at the expense of the main channel, that WILL and DO show much more macroblocking than if they were at full datarates.
A good example would be like watching good streaming videos on the internet on a broadand connection at a high data rate like 3 to 5 Megabits /sec, then trying to watch the same video on a dial up low data rate phone connection like 33.6 to 56 Kilobits /sec. The video will suffer a lot of blocking issues because the video bandwidth exceeds the connetion bandwidth.
Cox is having to keep the full data rate available in case the local stations get closer to using their maximum bitrate again. Unfortunately, you can't move bits around between QAMs or modulators. Moving to Switched Digital Video, EVERYTHING is eventually converted to IP and sent to the end user and any and all available extra Mbps can be used wherever they are needed to cover the bandwidth needs of the video.
Cox and other cable co's are in the process of moving and grouping channels together to make more efficient use of current channel needs right now, and moving to Switched Digital Video for even more bandwidth down the road. That that takes millions of dollars in equipment swapouts in all the headends and all the thousands of neighborhood nodes. Gains underway will yield enough room for about 6 HD channels in the near future and around 30 more HD channels by the time the conversion is completed. When asked about future HD channels in an interview, The Cox corporate executves have been quoted as saying " All of them"
Originally Posted by foghorn2
Maybe Cox should alter and compress them a little and give the customers more content esp. HD!
That is what D* has been doing for a while now and what E* is starting to do more of. They are reducing overall resolution by 25% and datarates by about the same. Those sat subs are leaving and moving to cable to get the last bastion of full resolution they can get.