so is the unlocking code changed frequently? I would assume it would need to be changed frequently, and a new unlock code sent to the boxes every time. But then I'm back to "how they can verify which dishes (boxes) are legit and which ones aren't"?The thing I know about it is the TV top boxes that decode the information. Honest people have to pay for an unlocking code.
This complicates things even more in my mind; I had not thought of the separate access to individual channels. How do they keep track of that?I have DirecTV and they have a record of the serial number of the box coupled with the electronic ID of the access card. They periodically send codes to these receivers that enables the decoding process. I also have a receiver/access card in my RV. If I don't go anywhere in the RV and connect it to a dish for a month or so, I have to call them to get it re-authorized. No big deal other than just not being sure whether I will need to do it or not. The authorizing of additional receivers on a given account is called Mirroring. Each receiver that is mirrored has the same access as the primary.
In my mind, this seems to necessitate the dish actually broadcasting back to the satellite to verify identity. So I must be wrong about it being just a receiver. It must be a transceiver. would you agree?The "permissions for your account" are transmitted periodically to each receiver and like you say, if a given receiver isn't connected to an antenna source, it won't get the new codes. If I want to add a channel or buy a pay-per-view movie, I just call them and they adjust my account.
No, there is no transmission from the subscriber to DirecTV. All permissions are sent from DirecTV to the subscriber, based on DirecTV's records of what the subscriber is paying for.In my mind, this seems to necessitate the dish actually broadcasting back to the satellite to verify identity. So I must be wrong about it being just a receiver. It must be a transceiver. would you agree?
You can find the entire article here.At the broadcast center, the high-quality digital stream of video goes through an MPEG encoder, which converts the programming to MPEG-4 video of the correct size and format for the satellite receiver in your house.
Encoding works in conjunction with compression to analyze each video frame and eliminate redundant or irrelevant data and extrapolate information from other frames. This process reduces the overall size of the file. Each frame can be encoded in one of three ways:
As an intraframe, which contains the complete image data for that frame. This method provides the least compression.
As a predicted frame, which contains just enough information to tell the satellite receiver how to display the frame based on the most recently displayed intraframe or predicted frame. A predicted frame contains only data that explains how the picture has changed from the previous frame.
As a bidirectional frame, which displays information from the surrounding intraframe or predicted frames. Using data from the closest surrounding frames, the receiver interpolates the position and color of each pixel.
Encryption and Transmission
After the video is compressed, the provider encrypts it to keep people from accessing it for free. Encryption scrambles the digital data in such a way that it can only be decrypted (converted back into usable data) if the receiver has the correct decryption algorithm and security keys.
Once the signal is compressed and encrypted, the broadcast center beams it directly to one of its satellites. The satellite picks up the signal with an onboard dish, amplifies the signal and uses another dish to beam the signal back to Earth, where viewers can pick it up.
Ok, I was just reading a different site and confirmed that the dish can't transmit.No, there is no transmission from the subscriber to DirecTV. All permissions are sent from DirecTV to the subscriber, based on DirecTV's records of what the subscriber is paying for.
the howstuffworks page is the one I was just reading .According to HowStuffWorks.com:
You can find the entire article here.
You also might find this Wikipedia Article useful.
does not explain how your decryption algorithm and security keys get into your box but not into my box.Encryption scrambles the digital data in such a way that it can only be decrypted (converted back into usable data) if the receiver has the correct decryption algorithm and security keys.
hidden data streams?Access flags can be downloaded to the subscriber's card either over the air (via 'hidden' data streams) or by using the box's built in modem