POWER MANAGEMENT SYSTEM AND METHOD FOR VEHICLE LOCATING UNIT

• US 20140105089A1
• Filed: 12/02/2013
• Published: 04/17/2014
• Est. Priority Date: 10/23/2009
• Status: Active Grant

• Current Assignee: Calamp Wireless Networks Inc. (CalAmp Corporation)
• Original Assignee: LoJack Corporation (Solera Holdings Incorporated)
• Inventors: Meacci, Fabio, Rhodes, Jesse L., Goodwin, Michael, Justice, James A.
• Granted Patent: US 9,565,636 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: B60R 25/102 a signal being sent to a remote location, e.g. a radio signal being transmitted to a police station, a security company or the owner
• CPC Class Codes: B60R 25/403 Power supply in the vehicle
• CPC Class Codes: G08G 1/20 Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 52/0235 where the received signal is a power saving command
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Improved power management for a vehicle locating unit is achieved by receiving a transmission from a communication source, each transmission including at least one message frame having a data field and at least one auxiliary field; entering a wake mode upon indexing the assigned message frame of the receiver in the transmission; matching the pattern of bits of at least one auxiliary field of the indexed frame with one or more stored patterns of bits expected for that auxiliary field; and returning to the sleep mode as soon as a mismatch is determined or processing the message if no mismatch occurs.

Claims

1-14. -14. (canceled)

15. A power management system for a vehicle locating unit, the vehicle locating unit having a receiver for receiving at an assigned message frame from a communications source an intermittent transmission, wherein each intermittent transmission includes at least one assignable message frame, the power management system comprising:

a processing device for controlling wake and sleep modes of the receiver; and

a memory for storing a plurality of memory bit patterns for comparison with a pattern of bits contained in some portion of an assigned message frame,

wherein the processing device is configured to perform the following steps;

index to the receiver'"'"'s assigned message frame in the intermittent transmission; and

re-enter the wake-up mode after indexing,

wherein operation of the system subjects the receiver to a constant average current draw due to indexing.

16. The system of claim 15, the processing device further configured to perform the following steps:

while in wake mode, match the pattern of bits contained in some portion of the assigned message frame with each of the plurality of memory bit patterns, and

return to the sleep mode if a mismatch is detected.

17. The system of claim 15, the processing device further configured to perform the following steps:

re-enter sleep mode if the expected start of the intermittent transmission is not detected until an expected start of a next intermittent transmission.

18. The system of claim 15, the vehicle locating unit further comprises a transmitter for transmitting reply code and each intermittent transmission includes at least one of an activate command, a de-activate command, and a speed-up command, wherein the processing device is further configured to perform the following steps:

upon receipt of an activate command, switch said transmitter from a de-activated state to a slow mode state;

switch said transmitter from the slow mode state to a slower, second slow mode state after a predetermined period; and

upon receipt of a speed-up command, switch said transmitter from at least one of the slow mode state and the second slow mode state to a fast mode state; and

switch the transmitter from the fast mode state to the slow mode state after a predetermined period.

19. The system of claim 18, wherein the processing device is further configured to perform the steps of:

switch the transmitter from the second slow mode state to a slower, third slow mode state after a preselected period; and

switch said transmitter from the third slow mode state to the fast mode state upon receipt of a speed-up command.

20. The system of claim 19, wherein the processing device is further configured to perform the step of de-activate the transmitter from any of the mode states to a de-activated state upon receipt of a de-activate command.

21. The system of claim 15, the processing device further configured to perform the following steps prior to index to the receiver'"'"'s assigned message frame in the intermittent transmission:

enter a sleep mode until an expected start of a next intermittent transmission;

enter a wake mode corresponding to an expected start of the intermittent transmission; and

after detecting the expected start of the intermittent transmission, re-enter sleep mode.

22. A method of power management for a vehicle locating unit, the vehicle locating unit having a receiver for receiving at an assigned message frame from a communications source an intermittent transmission, wherein each intermittent transmission includes at least one assignable message frame, a processing device for controlling wake and sleep modes of the receiver;

and a memory for storing a plurality of memory bit patterns for comparison with a pattern of bits contained in some portion of an assigned message frame, the method comprising the receiver;

indexing to the receiver'"'"'s assigned message frame in the intermittent transmission; and

re-entering the wake-up mode after indexing,

while subjecting the receiver to a constant average current draw.

23. The method of claim 22 further comprising:

while the receiver is in wake mode, matching the pattern of bits contained in some portion of the assigned message frame with each of the plurality of memory bit patterns, and returning the receiver to the sleep mode if a mismatch is detected.

24. The method of claim 22 further comprising:

the receiver re-entering sleep mode if the expected start of the intermittent transmission is not detected until an expected start of a next intermittent transmission.

25. The method of claim 22 further comprising assigning a message frame to the receiver.

26. The method of claim 22 further comprising the receiver, before indexing:

entering a sleep mode until an expected start of a next intermittent transmission;

entering a wake mode corresponding to an expected start of the intermittent transmission; and

after detecting the expected start of the intermittent transmission, re-entering sleep mode.