초록 ▼

A system for tracking the location of, and for providing cellular telephone handoff for, a mobile cellphone user as the cellphone user moves from one cellzone to another. A boundary curve B12 between a first cellzone and an adjacent second cellzone is defined in an electronic map by an equation hB12

A system for tracking the location of, and for providing cellular telephone handoff for, a mobile cellphone user as the cellphone user moves from one cellzone to another. A boundary curve B12 between a first cellzone and an adjacent second cellzone is defined in an electronic map by an equation hB12(x,y,z)-K12=0 for points with spatial location coordinates (x,y,z) lying on the curve B12, where K12 is a selected constant. First and second quasi-boundary curves QB1 and QB2, lying within the first and second cellzones, respectively, are defined, where each point on the curve QBi (i=1,2) lies at a selected distance di from the boundary curve B12. A region CR12 of points lying between the quasi-boundary curves QB1 and QB2 and including the boundary curve B12 is defined. The present location of the cellphone user is determined using a Satellite Positioning System (SATPS) such as GPS or GLONASS. Cellular telephone service for the cellphone user is provided (1) by a first cellular service provider or (2) by a second cellular service provider, when the cellphone user is located (1) within the first cellzone, not including the overlap region CR12, or (2) within the second cellzone, not including the overlap region CR12. When the cellphone user enters the region CR12 from within the first cellzone and proceeds toward the boundary curve B12, the system carried by the cellphone user notifies at least one of the first and second cellular service providers that the cellphone user is about to leave the first cellzone and about to enter the second cellzone. The system may be extended (1) to determine the approximate location of a missing vehicle and (2) to dynamically change the boundary curves of at least one cellzone to relieve cellular service overloading that occurs within that cellzone.

대표청구항 ▼

A method for providing handoff between at least two cellzones for a mobile cellphone user, the method comprising the steps of: providing a cellphone user with a cellular telephone that can communicate with a selected telephone through a first cellular telephone service provider, when the cellular te

A method for providing handoff between at least two cellzones for a mobile cellphone user, the method comprising the steps of: providing a cellphone user with a cellular telephone that can communicate with a selected telephone through a first cellular telephone service provider, when the cellular telephone is located within a first cellzone, and can communicate with the selected telephone through a second cellular telephone service provider, when the cellular telephone is located within a second cellzone that is adjacent to the first cellzone; providing the cellphone user with a Satellite Positioning System (SATPS) antenna and SATPS receiver/processor and with a transmitter, to receive SATPS signals from a plurality of SATPS satellites, to determine the present location of the SATPS antenna from analysis of these SATPS signals, and to transmit information on the present location of the SATPS antenna to a cellular telephone service provider for a cellzone in which the antenna is presently located; providing the cellphone user with a microprocessor and associated memory, connected to the cellular telephone and to the SATPS receiver/processor, that contains an electronic map of at least the first and second cellzones; providing a cellzone boundary curve B12 between the first and second cellzones, where B12 is defined on the electronic map by an equation hB12(xB12,yB12,zB12)=0, where (xB12,yB12,zB12) are the spatial location coordinates of a point lying on the boundary curve B12, where the equation hB12(x,y,z)0 indicates that a point with coordinates (x,y,z) is within a first region including the first cellzone and not including the second cellzone, and where the equation hB12(x,y,z)>0 indicates that the point with coordinates (x,y,z) is within a second region including the second cellzone and not including the first cellzone; providing a first quasi-boundary curve QB1 within the first cellzone that is defined on the map by a curve of points with coordinates (xQB1,yQB1,zQB1) within the first cellzone for which the perpendicular footer distance dfB12(x,y,z) of each point (xQB1,yQB1,zQB1) on the curve QB1 to its perpendicular footer on the curve B12 satisfies the relation dfB12(xQB1,yQB1,zQB1)=d1, where d1 is a selected positive distance; providing a second quasi-boundary curve QB2 within the second cellzone that is defined on the map by a curve of points with coordinates (xQB2,yQB2,zQB2) within the second cellzone for which the perpendicular footer distance dfB12(x,y,z) of each point (xQB2,yQB2,zQB2) on the curve QB2 to its perpendicular footer on the curve B12 satisfies the relation dfB12(xQB2,yQB2,zQB2)=d2, where d2 is a selected positive distance; defining a region CR12 of points lying between the first quasi-boundary curve QB1 and the second quasi-boundary curve QB2, including at least a portion of the boundary curve B12; when the SATPS antenna is within at least one of the first cellzone and the second cellzone, determining the antenna\s spatial location coordinates (x(t),y(t),z(t)), which may vary with time t; determining whether the SATPS antenna\s spatial location coordinates satisfy the two relations hB12(x(t),y(t),z(t))0 and dfB12(x(t),y(t),z(t))≥d1, and when these two relations are both satisfied, determining that the cellphone user is presently in the first cellzone; when the SATPS antenna is within the first cellzone and not within the region CR12, providing cellular telephone service for the cellphone user with the first cellular telephone service provider; determining whether the SATPS antenna\s spatial location coordinates satisfy the two relations hB12(x(t),y(t),z(t))0 and dfB12(x(t),y(t),z(t))fB12(x(t),y(t),z(t)) is decreasing with increasing time t, notifying at least one of the first and second cellular telephone service providers that the cellphone user will soon pass from the first cellzone into the second cellzone; and determining whether the SATPS antenna\s spatial location coordinates satisfy the relation hB12(x(t),y(t),z(t))>0, and when this relation is satisfied and the distance dfB12(x(t),y(t),z(t)) is increasing with increasing time t, notifying at least one of the first and second cellular telephone service providers that the cellphone user has passed from the first cellzone into the second cellzone.