Power saving operation in a GPS-based asset tracking unit
First Claim
1. An asset tracking unit, comprising:
- a GPS (Global Positioning System) receiver configured to selectively receive GPS signals from GPS satellites; and
a controller coupled to the GPS receiver and programmed to;
activate the GPS receiver in response to a predetermined occurrence;
determine whether the GPS receiver has received within a first predetermined attempt period of time a set of GPS signals adequate to determine a location of the asset tracking unit;
if the controller determines that the GPS receiver did not receive the set of the GPS signals within the first predetermined attempt period of time, deactivate the GPS receiver for a first delay period of time;
activate the GPS receiver upon completion of the first delay period of time;
determine whether the GPS receiver has received within a second predetermined attempt period of time, immediately following the first delay period of time, a set of GPS signals adequate to determine the location of the asset tracking unit;
if the controller determines that the GPS receiver did not receive the set of GPS signals within the second predetermined attempt period of time, deactivate the GPS receiver for a second delay period of time that is longer than the first delay period of time; and
activate the GPS receiver upon completion of the second delay period of time.
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0 Petitions
Accused Products
Abstract
A GPS receiver is activated and it is determined whether the GPS receiver has received within a first predetermined attempt period of time a set of GPS signals that is adequate to determine a location of the GPS receiver. If not, the GPS receiver is deactivated for a first delay period of time. The GPS receiver is then activated again and it is determined whether the GPS receiver has received a complete set of GPS signals within a second predetermined attempt period. If not, the GPS receiver is deactivated for a second delay period of time that is longer than the first delay period of time. The GPS receiver is then activated once more and again attempts to acquire a complete set of GPS signals.
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Citations
22 Claims
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1. An asset tracking unit, comprising:
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a GPS (Global Positioning System) receiver configured to selectively receive GPS signals from GPS satellites; and
a controller coupled to the GPS receiver and programmed to;
activate the GPS receiver in response to a predetermined occurrence;
determine whether the GPS receiver has received within a first predetermined attempt period of time a set of GPS signals adequate to determine a location of the asset tracking unit;
if the controller determines that the GPS receiver did not receive the set of the GPS signals within the first predetermined attempt period of time, deactivate the GPS receiver for a first delay period of time;
activate the GPS receiver upon completion of the first delay period of time;
determine whether the GPS receiver has received within a second predetermined attempt period of time, immediately following the first delay period of time, a set of GPS signals adequate to determine the location of the asset tracking unit;
if the controller determines that the GPS receiver did not receive the set of GPS signals within the second predetermined attempt period of time, deactivate the GPS receiver for a second delay period of time that is longer than the first delay period of time; and
activate the GPS receiver upon completion of the second delay period of time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of operating a GPS (Global Positioning System) receiver, the method comprising:
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activating the GPS receiver in response to a predetermined occurrence;
determining whether the GPS receiver has received within a first predetermined attempt period of time a set of GPS signals adequate to determine a location of the GPS receiver;
if it is determined that the GPS receiver did not receive the set of the GPS signals within the first predetermined attempt period of time, deactivating the GPS receiver for a first delay period of time;
activating the GPS receiver upon completion of the first delay period of time;
determining whether the GPS receiver has received within a second predetermined attempt period of time, immediately following the first delay period of time, a set of GPS signals adequate to determine the location of the GPS receiver;
if it is determined that the GPS receiver did not receive the set of GPS signals within the second predetermined attempt period of time, deactivating the GPS receiver for a second delay period of time that is longer than the first delay period of time; and
activating the GPS receiver upon completion of the second delay period of time. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A method of operating a GPS (Global Positioning System) receiver, the method comprising:
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(a) attempting to acquire a complete set of GPS signals;
(b) determining that the attempt in (a) has failed;
(c) in response to the determination at (b), entering an idle state for a first predetermined period;
(d) emerging from the idle state at the end of the first predetermined period and again attempting to acquire a complete set of GPS signals;
(e) determining that the attempt in (d) has failed;
(f) in response to the determination at (e), entering an idle state for a second predetermined period that is longer than the first predetermined period;
(g) emerging from the idle state at the end of the second predetermined period and again attempting to acquire a complete set of GPS signals;
(h) determining that the attempt in (g) has failed;
(i) in response to the determination at (h), entering an idle state for a third predetermined period that is longer than the second predetermined period; and
(j) emerging from the idle state at the end of the third predetermined period and again attempting to acquire a complete set of GPS signals. - View Dependent Claims (18, 19)
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20. An asset tracking system, comprising:
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a gateway;
a plurality of asset tracking units, each coupled to a respective transportation vehicle and including;
a GPS (Global Positioning System) receiver configured to selectively receive GPS signals from GPS satellites;
a transmitter; and
a controller coupled to the GPS receiver and to the transmitter and programmed to;
activate the GPS receiver in response to a predetermined occurrence;
determine whether the GPS receiver has received within a first predetermined attempt period of time a set of GPS signals adequate to determine a location of the asset tracking unit;
if the controller determines that the GPS receiver did not receive the set of the GPS signals within the first predetermined attempt period of time, deactivate the GPS receiver for a first delay period of time;
activate the GPS receiver upon completion of the first delay period of time;
determine whether the GPS receiver has received within a second predetermined attempt period of time, immediately following the first delay period of time, a set of GPS signals adequate to determine the location of the asset tracking unit;
if the controller determines that the GPS receiver did not receive the set of GPS signals within the second predetermined attempt period of time, deactivate the GPS receiver for a second delay period of time that is longer than the first delay period of time;
activate the GPS receiver upon completion of the second delay period of time; and
if the controller determines that the GPS receiver received the set of GPS signals, control the transmitter so that the transmitter transmits to the gateway a message that indicates a current location of the respective asset tracking unit. - View Dependent Claims (21, 22)
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Specification