Geofence breach confidence
A system and method for a mobile device to efficiently use a geofence capability without draining its battery, and to allow flexibility in specifying various parameters related to geofencing, such as the latency and confidence in determining when or where a geofence breach occurs, and reducing the probability of not detecting a geofence breach.
1. A mobile device, comprising:
a set of receivers,
a modem having an integrated first processor,
a second processor, and
a memory communicatively coupled to the modem and configured to store instructions, that when executed by the first processor, perform a process comprising:
selecting a receiver from the set of receivers based upon a breach confidence setting;
selecting a time interval based upon the breach confidence setting;
identifying a component of a velocity vector in a direction of a geofence, wherein the velocity vector is a weighted sum of a set of velocity components estimated at a previous instance, the velocity vector has a direction of travel and a velocity magnitude in the direction of travel, and the component is a velocity magnitude in the direction of the geofence;
adjusting the time interval based on the component of the velocity vector;
obtaining location information from the selected receiver during the time interval;
calculating a position of the mobile device using the location information;
determining a breach of the geofence based upon the location information; and
waking up the second processor in response to the breach of the geofence.
2. The mobile device of claim 1 , further comprising:
an application processor, wherein the application processor comprises the second processor.
3. The mobile device of claim 1 , wherein the set of receivers comprises a WWAN (Wireless Wide Area Network) receiver and a GNSS (Global Navigation Satellite System) receiver.
4. The mobile device of claim 1 , wherein the process further comprises:
indexing into a table based upon the breach confidence setting to select the receiver and the time interval, wherein the table is stored in the memory.
5. A method for indicating a geofence breach by a mobile device, comprising:
providing a geofence client to a first processor integrated in a modem in the mobile device, wherein the geofence client specifies a breach confidence setting and the first processor is communicatively coupled to a memory;
selecting a receiver from a set of receivers in the mobile device based upon the breach confidence setting;
selecting a time interval based upon the breach confidence setting;
identifying a component of a velocity vector in a direction of a geofence, wherein the velocity vector is a weighted sum of a set of velocity components estimated at a previous instance, the velocity vector has a direction of travel and a velocity magnitude in the direction of travel, and the component is a velocity magnitude in the direction of the geofence;
adjusting the time interval based on the component of the velocity vector;
obtaining location information from the selected receiver during the time interval;
calculating a position of the mobile device using the location information;
determining a breach of the geofence based upon the location information; and
waking up a second processor in the mobile device in response to the breach of the geofence.
6. The method of claim 5 , wherein the second processor is an application processor of the mobile device.
7. The method of claim 5 , wherein the set of receivers comprises a WWAN (Wireless Wide Area Network) receiver and a GNSS (Global Navigation Satellite System) receiver.
8. The method of claim 5 , further comprising:
indexing into a table based upon the breach confidence setting to select the receiver and the time interval, wherein the table is stored in a memory of the mobile device.
9. A non-transitory computer-readable storage medium having instructions stored therein to cause a mobile device to execute a process comprising:
providing a geofence client to a first processor integrated in a modem in the mobile device, wherein the geofence client specifies a breach confidence setting and the first processor is communicatively coupled to a memory;
selecting a receiver from a set of receivers in the mobile device based upon the breach confidence setting;
selecting a time interval based upon the breach confidence setting;
identifying a component of a velocity vector in a direction of a geofence, wherein the velocity vector is a weighted sum of a set of velocity components estimated at a previous instance, the velocity vector has a direction of travel and a velocity magnitude in the direction of travel, and the component is a velocity magnitude in the direction of the geofence;
adjusting the time interval based on the component of the velocity vector;
obtaining location information from the selected receiver during the time interval;
calculating a position of the mobile device using the location information;
determining a breach of the geofence based upon the location information; and
waking up a second processor in the mobile device in response to the breach of the geofence.
10. The non-transitory computer-readable storage medium of claim 9 , wherein the second processor is an application processor for the mobile device.
11. The non-transitory computer-readable storage medium of claim 9 , wherein the set of receivers comprises a WWAN (Wireless Wide Area Network) receiver and a GNSS (Global Navigation Satellite System) receiver.
12. The non-transitory computer-readable storage medium of claim 9 , wherein the process further comprises: indexing into a table based upon the breach confidence setting to select the receiver and the time interval, wherein the table is stored in a memory of the mobile device.