Method for optimizing the sleep mode of telematics multimedia unit data modem

1. A method for managing power consumption in a remotely controllable vehicle, the method comprising:

operating a telematics multimedia unit (TMU) data modem of the vehicle in a remote standby mode; setting a communication mode corresponding to a communication mode most recently used by the TMU data modem;

setting a timer on the remote standby mode for a predetermined time;

deducting an amount of residual current in a battery of the vehicle by an operating current having a predetermined level according to a power usage condition in a predetermined period, wherein the power usage condition is determined based on a location of the TMU data modem;

monitoring whether the amount of residual current is lower than a threshold level after the predetermined time of the timer elapses; and

terminating the remote standby mode when the amount of residual current is lower than the threshold level after the predetermined time of the timer elapses;

wherein the predetermined period is determined based on an error in a loading time and a current reduction time during the remote standby mode.

2. The method according to claim 1 , wherein the location of the TMU data modem is one of a handover region, a shadow communication region, a superposition region of strong and weak electric fields, and an international roaming region.

3. The method according to claim 2 , wherein the deducting of the amount of residual current in the battery comprises:

when the TMU data modem is located in the shadow communication region,

determining whether a communication service is currently available in the shadow communication region; and

determining whether the communication service has previously been available in the shadow communication region.

4. The method according to claim 3 , wherein the deducting of the amount of residual current in the battery further comprises:

when the communication service is currently available in the shadow communication region and has previously been available in the shadow communication region,

deducting the amount of residual current in the battery by an amount of current used for a number of receptions of emergency short message service (SMS) messages and a number of callings to a telematics center performed by the TMU data modem.

5. The method according to claim 3 , wherein the deducting of the amount of residual current in the battery further comprises:

when the communication service is currently available in the shadow communication region but has not previously been available in the shadow communication region,

deducting the amount of residual current in the battery by a predetermined amount for registration in the predetermined period and an amount of current used for the number of receptions of emergency SMS messages and the number of callings to the telematics center performed by the TMU data modem.

6. The method according to claim 3 , wherein the deducting of the amount of residual current in the battery further comprises:

when the communication service is not available currently in the shadow communication region but has previously been available in the shadow communication region,

deducting the amount of residual current in the battery by a predetermined amount for search in the predetermined period and an amount of current used for the number of receptions of emergency SMS messages and the number of callings to the telematics center performed by the TMU data modem.

7. The method according to claim 3 , wherein the deducting of the amount of residual current in the battery further comprises:

when the communication service is not available currently in the shadow communication region and has not previously been available in the shadow communication region,

deducting the amount of residual current in the battery by a predetermined amount in each period that a procedure is performed when the communication service is not available in the shadow communication region.

8. The method according to claim 2 , wherein the deducting of the amount of residual current in the battery comprises:

when the TMU data modem is located in the superposition region of strong and weak electric fields,

determining an occurrence of a telematics center call rejection, an occurrence of an emergency SMS message reception, or an occurrence of an emergency SMS message rejection in the superposition region of strong and weak electric fields; and

deducting the amount of residual current in the battery by a predetermined amount for search in the predetermined period when there is no failure in any of: the telematics center call, emergency SMS message generation, and the emergency SMS message rejection.

9. The method according to claim 2 , wherein the deducting of the amount of residual current in the battery comprises:

when the TMU data modem is located in the superposition region of strong and weak electric fields,

determining an occurrence of a telematics center call rejection, an occurrence of an emergency SMS message reception, or an occurrence of an emergency SMS message rejection in the superposition region of strong and weak electric fields; and

determining a receiving electric field level in the superposition region.

10. The method according to claim 9 , wherein the deducting of the amount of residual current in the battery further comprises:

when the telematics center call is rejected,

deducting the amount of residual current in the battery by an amount corresponding to a number of predetermined periods of call rejection procedures performed in response to the receiving electric field level.

11. The method according to claim 9 , wherein the deducting of the amount of residual current in the battery further comprises:

when the emergency SMS message is received,

deducting the amount of residual current in the battery by an amount corresponding to a number of predetermined periods of message reception procedures performed in response to the receiving electric field level.

12. The method according to claim 9 , wherein the deducting of the amount of residual current in the battery further comprises:

when the emergency SMS message is rejected,

deducting the amount of residual current in the battery by an amount corresponding to a number of predetermined periods of message rejection procedures performed in response to the receiving electric field level.

13. The method according to claim 2 , wherein the deducting of the amount of residual current in the battery comprises:

when the TMU data modem is located in one of the handover region and the international roaming region,

determining a number of handover occurrences or a number of occurrences of searching a home network for roaming.

14. The method according to claim 13 , wherein the deducting of the amount of residual current in the battery further comprises:

when there are no handover occurrences or no occurrence of searching the home network for roaming,

deducting the amount of residual current in the battery by a predetermined amount for the communication service in the predetermined period.

15. The method according to claim 13 , wherein the deducting of the amount of residual current in the battery further comprises:

when there is at least one handover occurrence,

determining a receiving electric field level in the handover region; and

deducting the amount of residual current in the battery by an amount corresponding to a number of predetermined periods in which a handover procedure is performed in response to the receiving electric field level.

16. The method according to claim 15 , wherein the handover occurrence corresponds to an occurrence of tracking area update (TAU) when the communication mode is Long-Term Evolution (LTE).

17. The method according to claim 15 , wherein the handover occurrence corresponds to an occurrence of Routing Area Update (RAU) or Location Area Update (LAU) when the communication mode is Wideband Code Division Multiplexing Access (WCDMA) or Global System for mobile (GSM).

18. The method according to claim 15 , wherein the handover occurrence corresponds to an occurrence of registration when the communication mode is Code-division multiple access (CDMA).

19. The method according to claim 13 , wherein the deducting of the amount of residual current in the battery further comprises:

when there is at least one occurrence of searching the home network for roaming,

determining a receiving electric field level in the handover region; and

deducting the amount of residual current in the battery by an amount corresponding to a number of predetermined periods in which a procedure of searching the home network for roaming is performed.