Originally Posted by juryman
Now for a new set of problems. Switched cable providers. From WOW to Time Warner. Wanted to continue using a cable card. But that did not happen in the end. After several attempts with them, cablecard did not give me all the channels I signed up for. They claim that, unlike WOW, they provide TOO MANY channels for the cablecard to handle. SO only a limited number come through. They claim is has something to do with the broadcast frequencies and the card can only accept a certain range. Sounds like BS, but in the end, hooked up a cable box and the picture seems to look even better now on this old TV.
Not BS. It's a system called Switched Digital Video
. To get the most bang out of the bandwidth on their systems, cable providers only place some of the less frequently used channels on the network segment running through your neighborhood if people are watching them. If a switched channel's not there when someone ask for it, they allocate bandwidth for it and place it on the wire. The problem is that the QAM frequency of the transport stream containing the channel and program number within that stream will change every time it gets put up on a network segment. When a tuner wants such a channel it sends a message to the cable system asking for it and the cable system sends it back the information required to tune it. A use count is maintained for each switched channel and when it drops to zero the system is free to tear down that channel and use the bandwidth for something else. CableCARD is a unidirectional system; CC tuners cannot talk to the cable system to make these requests.
To support CableCARDs on SDV systems, CableLabs came up with a device called a Tuning Adapter. These devices connect to CableCARD hosts via USB; the hosts send their channel requests to the TA over USB, the TA forwards the request to the cable system which sends the tuning information to the TA on the cable, and the TA passes it to the host over USB. Of course, like the copy protection systems used on the cable, SDV protocols are not standard, so Cisco cable systems and Motorola systems use different protocols and require TAs which know those protocols. I believe that thus far no cable systems have had the temerity to charge anyone for the use of TAs.
I think that only retail CableCARD DVRs like TiVo and CableCARD PC tuner card software have the ability to use Tuning Adapters. Obviously other CableCARD devices like televisions would need firmware updates to deal with TAs and none of them are readily upgradeable; AFAIK
none of them has developed TA compatibility. I have a TA for my TiVo Premiere on Cox San Diego South. Recently it went belly up and until I got it replaced I couldn't tune channels like A&E, Lifetime, SyFy, Tennis, etc.
There's also a possibility that WOW upgraded their system from a 750 MHz to a 1 GHz one (Cox did that too) and placed some channels in bandwidth up above 750 and that the Mits' tuner can't get to them, or some combination of both (like Cox, though I don't think that they're using the extra bandwidth for video).