System and method for geographically locating a cellular phone
First Claim
1. A method for geographically locating a cellular phone, the method comprising:
- determining an effective cell-area for each of a first cell and a second cell in a cellular network; and
determining a handover area within which the cellular phone will be located when control of the cellular phone is transferred from the first cell to the second cell; and
when a handover event between the first and second cells occurs, using a geographical area corresponding to the determined handover area as a geographical location of the cellular phone at the time of the handover event,wherein the determinations of the handover area and the effective cell-area for each of the first cell and the second cell are made based on a topological relationship between the first cell and the second cell,wherein the cellular network comprises a first antenna for the first cell and a second antenna for the second cell, and wherein the topological relationship is determined from amongst a set of topological cases comprising;
a first topological case in which the first antenna and the second antenna are located at a common location;
a second topological case in which the first antenna and the second antenna are located at different locations, and in which the first cell and the second cell are oriented to face each other;
a third topological case in which the first antenna and the second antenna are located at different locations, and in which the first cell and the second cell do not overlap; and
a fourth topological case in which none of the first, second, and third topological cases are satisfied.
4 Assignments
0 Petitions
Accused Products
Abstract
According to an embodiment of the invention, there is disclosed a method for geographically locating a cellular phone. The method comprises: determining an effective cell-area for each of a first cell and a second cell in a cellular network; and determining a handover area within which the cellular phone is likely to be located when control of the cellular phone is transferred from the first cell to the second cell; wherein the determination of the handover area and the effective cell-area for each of the first cell and the second cell are made based on a topological relationship between the first cell and the second cell. Further related apparatus embodiments are also disclosed.
115 Citations
61 Claims
-
1. A method for geographically locating a cellular phone, the method comprising:
-
determining an effective cell-area for each of a first cell and a second cell in a cellular network; and determining a handover area within which the cellular phone will be located when control of the cellular phone is transferred from the first cell to the second cell; and when a handover event between the first and second cells occurs, using a geographical area corresponding to the determined handover area as a geographical location of the cellular phone at the time of the handover event, wherein the determinations of the handover area and the effective cell-area for each of the first cell and the second cell are made based on a topological relationship between the first cell and the second cell, wherein the cellular network comprises a first antenna for the first cell and a second antenna for the second cell, and wherein the topological relationship is determined from amongst a set of topological cases comprising; a first topological case in which the first antenna and the second antenna are located at a common location; a second topological case in which the first antenna and the second antenna are located at different locations, and in which the first cell and the second cell are oriented to face each other; a third topological case in which the first antenna and the second antenna are located at different locations, and in which the first cell and the second cell do not overlap; and a fourth topological case in which none of the first, second, and third topological cases are satisfied. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
-
-
30. An apparatus for geographically locating a cellular phone, the apparatus comprising:
-
an effective cell-area module for determining an effective cell-area for each of a first cell and a second cell in a cellular network; and a handover area module for determining a handover area within which the cellular phone will be located when control of the cellular phone is transferred from the first cell to the second cell; wherein the determinations of the handover area and the effective cell-area for each of the first cell and the second cell are made based on a topological relationship between the first cell and the second cell, and wherein the apparatus is arranged to when a handover event between the first and second cells occurs, use a geographical area corresponding to the determined handover area as a geographical location of the cellular phone at the time of the handover event, wherein the cellular network comprises a first antenna for the first cell and a second antenna for the second cell, and wherein the topological relationship is determined from amongst a set of topological cases comprising; a first topological case in which the first antenna and the second antenna are located at a common location; a second topological case in which the first antenna and the second antenna are located at different locations, and in which the first cell and the second cell are oriented to face each other; a third topological case in which the first antenna and the second antenna are located at different locations, and in which the first cell and the second cell do not overlap; and a fourth topological case in which none of the first, second, and third topological cases are satisfied. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55)
-
-
56. A method for geographically locating a cellular phone in a cellular network comprising a first antenna for a first cell and a second antenna for a second cell, the method comprising:
-
determining an effective radius Ri, for each of a set of i different topological relationships between the first cell and the second cell; determining an angle α
for which, when the first antenna is contained within the second cell, and when an angle β
formed by a line between the first antenna and the second antenna and a sector limit line of the second cell is less than the angle α
, the second cell will be extended beyond the sector limit line;determining a first extension width E1 of a first rectangular extension added to a sector limit line of the second cell when the angle is less than the angle α
;determining a second extension width E2 of a second rectangular extension added to a sector limit line of the second cell when the first antenna is outside the second cell, and when an inner angle formed between a sector limit line of the second cell and a line between the first antenna and the second antenna, is greater than 180 degrees; determining a first penumbra width W1 of a first rectangular strip between a line of equal intensity of signal reception from the first antenna and the second antenna, and a first strip limit proximal to a cell into which the cellular phone is moving; determining a second penumbra width W2 of a second rectangular strip between the line of equal intensity and a second strip limit proximal to a cell out of which the cellular phone is moving; and determining a handover area within which the cellular phone is likely to be located when control of the cellular phone is transferred from the first cell to the second cell, the determination of the handover area being based on at least a subset of the effective radii Ri, the angle α
;
the first extension width E1, the second extension width E2, the first penumbra width W1, and the second penumbra width W2.
-
-
57. A method for geographically locating a cellular phone, the method comprising:
-
determining an effective cell-area for each of a first cell and a second cell in a cellular network; determining a handover area within which the cellular phone will be located when control of the cellular phone is transferred from the first cell to the second cell; determining a first cell potential handover area by intersecting the effective cell-area of the first cell with the penumbra area; determining a second cell potential handover area by intersecting the effective cell-area of the second cell with the penumbra area; and determining the handover area for transfer of control of the cellular phone by forming the union of the first cell potential hand over area and the second cell potential handover area, when a handover event between the first and second cells occurs, using a geographical area corresponding to the determined handover area as a geographical location of the cellular phone at the time of the handover event, wherein the determinations of the handover area and the effective cell-area for each of the first cell and the second cell are made based on a topological relationship between the first cell and the second cell.
-
-
58. A method for geographically locating a cellular phone, the method comprising:
-
determining an effective cell-area for each of a first cell and a second cell in a cellular network; and determining a handover area within which the cellular phone will be located when control of the cellular phone is transferred from the first cell to the second cell; and when a handover event between the first and second cells occurs, using a geographical area corresponding to the determined handover area as a geographical location of the cellular phone at the time of the handover event, wherein the determinations of the handover area and the effective cell-area for each of the first cell and the second cell are made based on a topological relationship between the first cell and the second cell wherein determining the effective cell-area further comprises extending an edge of a sector-shaped cell, wherein extending the edge of the sector-shaped cell comprises, when a first antenna for the first cell is contained within the second cell, and when an angle β
formed by a line between the first antenna and a second antenna for the second cell and a sector limit line of the second cell, is less than a predetermined angle α
, extending the second cell beyond the sector limit line.
-
-
59. A method for geographically locating a cellular phone, the method comprising:
-
determining an effective cell-area for each of a first cell and a second cell in a cellular network; determining a handover area within which the cellular phone will be located when control of the cellular phone is transferred from the first cell to the second cell; determining a penumbra area around a line of equal intensity of reception between the first cell and the second cell wherein determining the penumbra area comprises; determining the location of the line of equal intensity; and determining a rectangular strip around the line of equal intensity; when a handover event between the first and second cells occurs, using a geographical area corresponding to the determined handover area as a geographical location of the cellular phone at the time of the handover event, wherein the determinations of the handover area and the effective cell-area for each of the first cell and the second cell are made based on a topological relationship between the first cell and the second cell.
-
-
60. An apparatus for geographically locating a cellular phone, the apparatus comprising:
-
an effective cell-area module for determining an effective cell-area for each of a first cell and a second cell in a cellular network; a handover area module for determining a handover area within which the cellular phone will be located when control of the cellular phone is transferred from the first cell to the second cell; and a penumbra area module for determining a penumbra area around a line of equal intensity of reception between the first cell and the second cell; wherein the handover area module comprises means for; determining a first cell potential handover area by intersecting the effective cell-area of the first cell with the penumbra area; determining a second cell potential handover area by intersecting the effective cell-area of the second cell with the penumbra area; and determining the handover area for transfer of control of the cellular phone by forming the union of the first cell potential handover area and the second cell potential handover area wherein the determinations of the handover area and the effective cell-area for each of the first cell and the second cell are made based on a topological relationship between the first cell and the second cell, and wherein the apparatus is arranged to. when a handover event between the first and second cells occurs, use a geographical area corresponding to the determined handover area as a geographical location of the cellular phone at the time of the handover event.
-
-
61. An apparatus for geographically locating a cellular phone, the apparatus comprising:
-
an effective cell-area module for determining an effective cell-area for each of a first cell and a second cell in a cellular network; and a handover area module for determining a handover area within which the cellular phone will be located when control of the cellular phone is transferred from the first cell to the second cell; and wherein the effective cell-area module comprises means for determining an extension of an edge of a sector-shaped cell; wherein the effective cell-area module comprises means for determining an extension of an edge of a sector-shaped cell by; determining whether a first antenna for the first cell is contained within the second cell, and whether an angle β
formed by a line between the first antenna and a second antenna for the second cell and a sector limit line of the second cell, is less than a predetermined angle α
; and
, if so,extending the second cell beyond the sector limit line wherein the determinations of the handover area and the effective cell-area for each of the first cell and the second cell are made based on a topological relationship between the first cell and the second cell, and wherein the apparatus is arranged to. when a handover event between the first and second cells occurs, use a geographical area corresponding to the determined handover area as a geographical location of the cellular phone at the time of the handover event.
-
Specification