Emergency alert signaling method and DTV receiver

1. An emergency alert signaling method for use by a digital television (DTV) receiver, the method comprising:

determining whether the DTV receiver is on a power-on mode or a power-off mode;

periodically tuning to a first emergency alert channel to receive a first master guide table when the DTV receiver is on the power-off mode;

parsing the first master guide table without setting the DTV receiver on the power-on mode to determine whether a new emergency alert message is being received; and

automatically setting the DTV receiver on the power-on mode and tuning to a second emergency alert channel when the parsed first master guide table indicates that the new emergency alert message is being received.

2. The method of claim 1 , wherein the first master guide table includes an emergency flag to indicate whether the new emergency alert message is being received.

3. The method of claim 1 , further comprising receiving a first emergency alert table having the new emergency alert message through the tuned emergency alert channel.

4. The method of claim 3 , further comprising parsing the new emergency alert message from the first emergency alert table and scrolling the parsed new emergency alert message across a portion of a video screen.

5. The method of claim 1 , further comprising:

determining whether the DTV receiver is currently on a terrestrial broadcast mode when the DTV receiver is on the power-on mode;

periodically tuning to the emergency alert channel to receive a second master guide table when the DTV receiver is not on the terrestrial broadcast mode;

parsing the second master guide table to determine whether a new emergency alert message is being received; and

automatically tuning to the emergency alert channel when the parsed second master guide table indicates that the new emergency alert message is being received.

6. The method of claim 5 , further comprising receiving a second emergency alert table having the new emergency message through the tuned emergency alert channel.

7. The method of claim 6 , further comprising parsing the new emergency alert message from the second emergency alert table and scrolling the parsed new emergency alert message across a portion of a video screen.

8. The method of claim 1 , further comprising:

determining whether the DTV receiver is currently on a terrestrial broadcast mode when the DTV receiver is on the power-on mode;

receiving a second master guide table through a terrestrial broadcast channel when the DTV receiver is on the terrestrial broadcast mode;

parsing the second master guide table to determine whether a new emergency alert message is being received; and

automatically tuning to a predefined emergency channel when the parsed second master guide table indicates that the new emergency alert message is being received.

9. The method of claim 8 , further comprising receiving a second emergency alert table having the new emergency message through the tuned emergency alert channel.

10. The method of claim 9 , further comprising parsing the new emergency alert message from the second emergency alert table and scrolling the parsed new emergency message across a portion of a video screen.

11. An emergency alert signaling method for use by a digital television (DTV) receiver, the method comprising:

determining whether the DTV receiver is on a power-on mode or a power-off mode;

periodically tuning to a first emergency alert channel to receive a first emergency alert table when the DTV receiver is on the power-off mode;

parsing the first emergency alert table without setting the DTV receiver on the power-on mode to determine whether the first emergency alert table includes a new emergency alert message; and

automatically setting the DTV receiver on the power-on mode and tuning to a second the emergency alert channel when the parsed first emergency alert table includes the new emergency message.

12. The method of claim 11 , wherein the first emergency alert table includes an information field specifying a sequence number of the new emergency alert message.

13. The method of claim 11 , further comprising parsing the new emergency alert message from the first emergency alert table and scrolling the parsed new emergency alert message across a portion of a video screen.

14. The method of claim 11 , further comprising:

determining whether the DTV receiver is currently on a terrestrial broadcast mode when the DTV receiver is on the power-on mode;

periodically tuning to the emergency alert channel to receive a second emergency alert table when the DTV receiver is not on the terrestrial broadcast mode;

parsing the second emergency alert table to determine whether the second emergency alert table includes a new emergency alert message; and

automatically tuning to the emergency alert channel when the parsed second emergency alert table includes the new emergency alert message.

15. The method of claim 14 , wherein the second emergency alert table includes an information field specifying a sequence number of the new emergency alert message.

16. The method of claim 14 , further comprising parsing the new emergency message from the second emergency alert table and scrolling the parsed new emergency alert message across a portion of a video screen.

17. The method of claim 11 , further comprising:

determining whether the DTV receiver is currently on a terrestrial broadcast mode when the DTV receiver is on the power-on mode;

periodically tuning to the emergency alert channel to receive a second emergency alert table when the DTV receiver is on the terrestrial broadcast mode;

parsing the second emergency alert table to determine whether the second emergency alert table includes a new emergency alert message; and

automatically tuning to the emergency alert channel when the parsed second emergency alert table includes the new emergency alert message.

18. The method of claim 17 , wherein the second emergency alert table includes an information field specifying a sequence number of the new emergency alert message.

19. The method of claim 17 , further comprising parsing the new emergency message from the second emergency alert table and scrolling the parsed new emergency alert message across a portion of a video screen.

20. A digital television (DTV) receiver, comprising:

a tuner;

a microcomputer determining whether the DTV receiver is on a power-on mode or power-off mode and controlling operation of the tuner to periodically tune to a first emergency alert channel to receive a first master guide table when the DTV receiver is on the power-off mode; and

a demodulator parsing the first master guide table without setting the DTV receiver on the power-on mode to determine whether a new emergency alert message is being received, wherein the microcomputer automatically sets the DTV receiver on the power-on mode and controls operation of the tuner to tune to a second the emergency alert channel when the parsed first master guide table indicates that the new emergency alert message is being received.

21. The DTV receiver of claim 20 , wherein the first master guide table includes an emergency flag to indicate whether the new emergency alert message is being received.

22. The DTV receiver of claim 20 , wherein the tuner further receives a first emergency alert table having the new emergency alert message through the tuned emergency alert channel.

23. The DTV receiver of claim 22 , wherein the demodulator further parses the new emergency alert message from the first emergency alert table.

24. The DTV receiver of claim 23 , further comprising a controller controlling operation of a display device in order to scroll the parsed new emergency alert message across a portion of a video screen.

25. The DTV receiver of claim 20 , wherein the microcomputer further determines whether the DTV receiver is currently on a terrestrial broadcast mode when the DTV receiver is on the power-on mode, and further controls operation of the tuner to periodically tune to the emergency alert channel to receive a second master guide table when the DTV receiver is not on the terrestrial broadcast mode.

26. The DTV receiver of claim 20 , wherein the microcomputer further determines whether the DTV receiver is currently on a terrestrial broadcast mode when the DTV receiver is on the power-on mode, and further controls operation of the tuner to receive a second master guide table through a terrestrial broadcast channel when the DTV receiver is on the terrestrial broadcast mode.

27. A digital television (DTV) receiver, comprising:

a tuner;

a microcomputer determining whether the DTV receiver is on a power-on mode or a power-off mode and controlling operation of the tuner to periodically tune to a first predefined emergency alert channel to receive a first emergency alert table when the DTV receiver is on the power-off mode; and

a demodulator parsing the first emergency alert table without setting the DTV receiver on the power-on mode to determine whether the first emergency alert table includes a new emergency alert message, wherein the microcomputer automatically sets the DTV receiver on the power-on mode and controls operation of the tuner to tune to a second emergency alert channel when the parsed first emergency alert table includes the new emergency message.

28. The DTV receiver of claim 27 , wherein the first emergency alert table includes an information field specifying a sequence number of the new emergency alert message.

29. The DTV receiver of claim 27 , wherein the demodulator further parses the new emergency alert message from the first emergency alert table.

30. The DTV receiver of claim 29 , further comprising a controller controlling operation of a display device in order to scroll the parsed new emergency alert message across a portion of a video screen.

31. The DTV receiver of claim 27 , wherein the microcomputer further determines whether the DTV receiver is currently on a terrestrial broadcast mode when the DTV is on the power-on mode, and controls operation of the tuner to periodically tune to the emergency alert channel to receive a second emergency alert table when the DTV receiver is not on the terrestrial broadcast mode.

32. The DTV receiver of claim 27 , wherein the microcomputer further determines whether the DTV receiver is currently on a terrestrial broadcast mode when the DTV receiver is on the power-on mode, and controls operation of the tuner to periodically tune to the emergency alert channel to receive a second emergency alert table when the DTV receiver is on the terrestrial broadcast mode.

33. The method of claim 1 , wherein the DTV receiver is on the power-off mode when a broadcast audio and video (AV) stream processing block in the DTV receiver is inactivated.

34. The method of claim 11 , wherein the DTV receiver is on the power-off mode when a broadcast audio and video (AV) stream processing block in the DTV receiver is inactivated.

35. The DTV receiver of claim 20 , wherein DTV receiver is on the power-off mode when a broadcast audio and video (AV) stream processing block in the DTV receiver is inactivated.

36. The DTV receiver of claim 27 , wherein DTV receiver is on the power-off mode when a broadcast audio and video (AV) stream processing block in the DTV receiver is inactivated.

37. The method of claim 1 , wherein the first and second emergency channels are same.

38. The method of claim 11 , wherein the first and second emergency channels are same.

39. The DTV receiver of claim 20 , wherein the first and second emergency channels are same.

40. The DTV receiver of claim 27 , wherein the first and second emergency channels are same.