Digital broadcasting system and method of processing data

Abstract

A digital broadcasting system and method of processing data are disclosed. Herein, a method of processing data in a transmitting system includes creating a data group including a plurality of mobile service data packets, re-adjusting a relative position of at least one main service data packet of a main service data section, the main service data section including a plurality of main service data packets, and multiplexing the mobile service data of the data group and the main service data of the main service data section in burst units. Herein, a position of an audio data packet among the main service data packets of the main service data section may be re-adjusted. Also, a position of an audio data packet included in the main service data section may be re-adjusted based upon a multiplexing position of the main service data section.

What is claimed is: 
     
       1. A method of processing a broadcast signal in a broadcast transmitter, the method comprising:
 identifying a null data packet included in an input stream that includes the null data packet and a first broadcast data packet for a first service; 
 deleting the identified null data packet in the input stream; 
 randomizing first broadcast data of the first broadcast data packet in the input stream in which the null data packet is deleted; 
 first encoding the randomized first broadcast data systematically; 
 interleaving the first-encoded first broadcast data; and 
 transmitting the broadcast signal including the interleaved first broadcast data, 
 wherein the broadcast signal further includes second broadcast data for a second service multiplexed with the first broadcast data and information for identifying the first broadcast data and the second broadcast data, and 
 wherein the first broadcast data and the second broadcast data have a different robustness level. 
 
     
     
       2. The method of  claim 1 , wherein the first broadcast data are randomized after a sync byte in the first broadcast data packet including the first broadcast data is removed. 
     
     
       3. The method of  claim 1 , further comprising:
 second encoding the interleaved first broadcast data. 
 
     
     
       4. The method of  claim 1 , wherein the null data packet is included in the input stream in order to accommodate variable data rate services in the input stream having a constant bit rate. 
     
     
       5. A broadcast transmitter for processing a broadcast signal, the broadcast transmitter comprising:
 an input processor for identifying a null data packet included in an input stream that includes the null data packet and a first broadcast data packet for a first service, and deleting the identified null data packet in the input stream; 
 a randomizer for randomizing first broadcast data of the first broadcast data packet in the input stream in which the null data packet is deleted; 
 a first encoder for first encoding the randomized first broadcast data systematically; 
 an interleaver for interleaving the first-encoded first broadcast data; and 
 a transmitting unit for transmitting the broadcast signal including the interleaved first broadcast data, 
 wherein the broadcast signal further includes second broadcast data for a second service multiplexed with the first broadcast data and information for identifying the first broadcast data and the second broadcast data, and 
 wherein the first broadcast data and the second broadcast data have a different robustness level. 
 
     
     
       6. The broadcast transmitter of  claim 5 , wherein the first broadcast data are randomized after a sync byte in the first broadcast data packet including the first broadcast data is removed. 
     
     
       7. The broadcast transmitter of  claim 5 , further comprising:
 a second encoder for second encoding the interleaved first broadcast data. 
 
     
     
       8. The broadcast transmitter of  claim 5 , wherein the null data packet is included in the input stream in order to accommodate variable data rate services in the input stream having a constant bit rate.