Patent ID: 8014525

Claim:
A system for transmitting digital broadcasting comprising: a main broadcasting system for adding a data packet through a main broadcasting network and a network identification code (NIC) to broadcasting signals, scrambling the broadcasting signals by using a predetermined scrambling key, and outputting scrambled broadcasting signals, wherein the main broadcasting system scrambles the predetermined key by using the NIC and transmits the scrambled key as a descrambling key; a repeating system for repeating the scrambled broadcasting signal transmitted by the main broadcasting system through a repeating network, wherein the repeating system adds a second NIC of the repeating network to the scrambled broadcasting signals and the repeating system outputs the modified scrambled broadcasting signals to a subscriber station on the repeating network, the second NIC is different from the NIC of the main broadcasting network and the second NIC is used for representing modified scrambled broadcasting signals outputted from the repeating system; and a mobile communication system for receiving the descrambling key from the main broadcasting system or the repeating system and transmitting the same to a charged subscriber station wherein the charged subscriber station descrambles the scrambled broadcasting signals by using the NIC extracted from the scrambled broadcasting signals and the descrambling key, the NIC is also used for identifying whether the scrambled broadcasting signal is from the main broadcasting system or the repeating system.