Systems and methods to identify a predefined geographical region in which a mobile device is located
Systems and methods including a mobile device determining the coordinates of its location using a location determination system, such as a global positioning system. A database stores the identifiers of cells representative of predefined regions in a hierarchical grid system. A server computer or the mobile device converts the coordinates of the location to one or more cell identifiers at different grid resolution levels and searches the database to find a match between the cell identifiers representing the regions and the cell identifiers representing the location of the mobile device to determine one or more regions in which the mobile device is located. For example, the hierarchical grid system can be constructed in a longitude latitude space of location coordinates, with resolution levels aligned with decimal precision levels of the location coordinates; and the cell identifiers can be constructed from the digits of the longitude and latitude coordinates.
1. A method implemented in a computing device, the method comprising:
storing, in the computing device, an identifier of a geographical region having a predefined geographical boundary;
storing, in the computing device, a set of cell identifiers, each of the cell identifiers identifying a cell that is determined to be within the predefined geographical boundary; wherein each respective cell identified by a corresponding cell identifier in the set of cell identifiers is a square area in a longitude latitude space of locations on the earth;
receiving, from a mobile device, a location of the mobile device;
converting, by the computing device, a set of coordinates of the location of the mobile device to a first cell identifier; and
determining, by the computing device, whether or not the location of the mobile device is within the geographical region based on searching the set of cell identifiers to determine whether or not the set has the first cell identifier.
2. The method of claim 1 , wherein the set of cells identified by the set of cell identifiers has a plurality of cell sizes corresponding to a plurality of predetermined cell resolution levels.
3. The method of claim 2 , wherein each cell resolution level of the plurality of predetermined cell resolution levels corresponds to a predetermined precision level of longitudes and latitudes of locations on the earth.
4. The method of claim 2 , wherein each cell resolution level of the plurality of predetermined cell resolution levels corresponds to a precision to a predetermined digit after the decimal point in longitude and latitude coordinates of locations on the earth.
5. A method implemented in a computing device, the method comprising:
storing, in the computing device, an identifier of a geographical region having a predefined geographical boundary;
storing, in the computing device, a set of cell identifiers, each of the cell identifiers identifying a cell that is determined to be within the predefined geographical boundary;
storing data mapping each cell identify in the set of cell identifiers to at least one region identifier;
receiving, from a mobile device, a location of the mobile device;
converting, by the computing device, a set of coordinates of the location of the mobile device to a first cell identifier;
determining, by the computing device, whether or not the location of the mobile device is within the geographical region based on searching the set of cell identifiers to determine whether or not the set has the first cell identifier; and
searching the set of cell identifiers to determine at least one region identifier associated with the first cell identifier.
6. The method of claim 5 , wherein the converting of the set of coordinates of the location includes:
generating two integers from longitude and latitude coordinates of the location according to a precision level; and
combining the two integers into the first cell identifier without using a floating point number computation.
7. The method of claim 6 , wherein a cell identified by the first cell identifier is a rectangle area in a longitude latitude space of locations on the earth.
8. A method implemented in a computing device, the method comprising:
storing, in the computing device, an identifier of a geographical region having a predefined geographical boundary;
storing, in the computing device, a set of cell identifiers, each of the cell identifiers identifying a cell that is determined to be within the predefined geographical boundary;
receiving, from a mobile device, a location of the mobile device;
converting, by the computing device, a set of coordinates of the location of the mobile device to a first cell identifier; wherein the set of coordinates includes longitude and latitude of the location; and the converting includes:
selecting digits from the longitude and the latitude of the location in accordance with a cell resolution level; and
combining the digits selected from the longitude and the latitude of the location into an integer representing the first cell identifier; and
determining, by the computing device, whether or not the location of the mobile device is within the geographical region based on searching the set of cell identifiers to determine whether or not the set has the first cell identifier.
9. A method implemented in a computing device, the method comprising:
storing, in the computing device, an identifier of a geographical region having a predefined geographical boundary;
storing, in the computing device, a set of cell identifiers, each of the cell identifiers identifying a cell that is determined to be within the predefined geographical boundary;
receiving, from a mobile device, a location of the mobile device;
converting, by the computing device, a set of coordinates of the location of the mobile device to a first cell identifier;
determining, by the computing device, whether or not the location of the mobile device is within the geographical region based on searching the set of cell identifiers to determine whether or not the set has the first cell identifier;
receiving data representing the predefined geographical boundary of the geographical region; and
identifying, in a hierarchy of cell grids, the set of cell identifiers that are determined to be within the predefined geographical boundary.
10. The method of claim 9 , wherein each grid in the hierarchy of cell grids corresponds to a rectangle grid in longitude latitude space of locations on the earth with a predetermined resolution level.
11. The method of claim 10 , wherein the predetermined resolution level corresponds to a precision level in a floating point representation of longitude and latitude coordinates.