1. Field of the Invention
The present invention relates to digital broadcasting, and more particularly, to a digital television signal and a method and apparatus of processing a digital television signal.
2. Discussion of the Related Art
Generally, a program and system information protocol (hereinafter, PSIP) is a protocol for channel tuning and broadcast schedule transmission in ATSC (advanced television systems committee) as the digital broadcasting standard in terrestrial and cable digital broadcasting environments. In addition, the PSIP is a standard protocol for a transfer of tables included within packets transferred by a multiplexed transport stream.
The PSIP defines many PSIP tables for the various purpose, and each PSIP table includes one or more sections which are similar to those of the program and system information (PSI) tables defined by MPEG (moving picture experts group). Each section included in a PSIP table includes a header containing basic information of the section and a body containing the actual data constituting the section. A broadcast receiver uses the basic information included in headers of various sections received from a broadcast transmitter in order to select (or detect) one or more pertinent sections, and this is often referred to as section-filtering. An example of the basic information is a table identifier which identifies a PSIP table.
However, a certain group of PSIP tables (e.g., a group of event information tables or extended text tables) have a common table identification. Therefore, the digital television (DTV) receiver is not able to distinguish them simply by section-filtering. In this case, the DTV receiver must parse bodies of the PSIP sections in order to detect a pertinent section, and this greatly increases the signal processing time and decreases the system's overall efficiency.