stuart628 said:
if I read that correctly that would also allow them to add channels (Hd and SD) channels at will without letting them worry about bandwidth is that correct (as going with ADS will allow them to do switched video)
ADS (advanced digital simulcast) is different than switched video. ADS requires more bandwidth as they will have the same 70 channels using bandwidth in both the analog and digital worlds. Many cable systems have gone ADS but not upgraded to switched video.
Once a system puts in switched video hardware they will only send the top 25 or so channels down the pipe at all times. All other channels would only be sent down the pipe as they are tuned in by the customer. For customers without a box when they try and tune in a channel via their analog TVs built-in tuner BHN will use this auto-sensing hardware so it in simple terms can listen for a certian frequency request. I'm not sure how all of this works and I'm being very simple in my wording but this is the gist of it all.
In simple terms beyond the top 25 most watched channels everything else would only be sent down when a customer tunes the channel in. Today all channels are sent down the cable cables all the time 24/7 and are assigned to different frequencies.
So for example on a cable system that is a 750Mhz cable system that is their total amount of bandwidth. The bandwidth is seperated into 6Mhz chunks. Most of the bandwidth is for video but quite a bit of it is used for internet service.
Also of note each analog channel takes 6Mhz of space. In that same 6Mhz of space they can fit two HD channels without much compression. They can do three if they compressed it more. About 5-10 digital channels can fit in that same 6Mhz space also. You can see just how much space an analog system uses.
So if your cable system has 70 analog channels those channels will use 420Mhz of the total 750Mhz system. This means that all other services including digital channels, VOD, internet and now phone service must be offered using the left over bandwidth. To give you an idea if the cable company required every customer to use a box and every customer had an HD box that in that same 420Mhz of space they could offer 140 or more HDTV channels.
So in simple terms they will have 25 channels always being sent down the pipe which would use only 150Mhz of the total 750Mhz system with switched video. If all other channels are sent down the pipe only when tuned in they would free up at least 50% of the TV bandwidth used.
I've been told that switched video on a 750Mhz system would allow the cable company to double the amount of bandwidth for HDTV channels along with being able to increase the speed of internet services to compete with Verizon. Can you hear 30Mbps down and 5Mbps UP because this is what switched video can do for cable but don't forget this costs quite a bit of money but much much much less than doing a typical system wide upgrade. Also note that many cable systems including the Tampa Bay BHN system have 850Mhz networks which means more bandwidth.