Abstract: Disclosed is a system and method for sending and receiving information of digital cable broadcasting, which comprises: a headend unit for assigning a packet identifier (PID) from within a range of PIDs to tables carrying data according to inclusion of service information (SI), constructing a transport packet (TP), and sending it using an MPEG communication method; and a receiving unit for receiving the TP from the headend unit, checking the PID of the TP to determine whether the TP includes SI, and determining how to process the TP depending on inclusion states of SI in the TP. The PID discriminates a TP including SI from a TP including other messages in transmission of MPEG-2 TPs from the headend unit to the receiving unit.

Abstract: Disclosed is an apparatus and method for descrambling transport stream (TS) data, the descrambling apparatus including: a TS packet input unit for determining from the value of a header of TS packet data whether the TS packet data are scrambled, and outputting determination results and the TS packet data; a descramble controller for applying a control signal to the TS packet input unit for the TS packet input unit to read the TS packet data, and outputting a scramble determination signal of a corresponding state based on the determination results; and a descrambler for determining from the state of the scramble determination signal whether the TS packet data from the TS packet input unit are scrambled, and determining whether to descramble the TS packet data.

Abstract: Disclosed is an apparatus and method for processing transport streams (TSs) and a delay-controlling apparatus that assigns a predetermined delay to MPEG-2 TS packets fed into a POD module in a digital cable broadcasting system, irrespective of a time delay caused by descrambling scrambled input TS packets, the apparatus including: a demultiplexer for receiving TSs and dividing them into scrambled and non-scrambled data; a descrambler controller for receiving the scrambled data from the demultiplexer and descrambling it; a delay controller for receiving the non-scrambled data from the demultiplexer and the descrambled data from the descrambler controller and delaying them by a predetermined time; and a remultiplexer for receiving the data from the delay controller, multiplexing them, and outputting the multiplexed data in the TS format.