Digital satellite television broadcasts their signal from a ground-based satellite, up to a transponder in space, which is in turn broadcast back down to earth to customers homes. If all that ground-based satellite is doing is broadcasting RF, how can Directv talk to each customers access cards individually using EPROM? Being a residential satellite installer, I know it doesn't use the phone line because I have activated many receivers without having the phone line hooked up.
I guess some frequencies or channels are used to send messages. When you want to activate a satellite receiver, you need to make sure it is on and receiving. A message is then sent on a frequency. This message contains the reference of the smart card and enables it to be unlocked. When the receiver gets the message, it is sent to the smartcard that then makes the receiver able to work and decode channels.
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