Efficient Location and Tracking of Mobile Subscribers
A method for locating and tracking devices in a mobile telephone network compries the steps of (a) receiving mobile telephone control parameters in a subscriber database; and (b) using one or more location parameter databases (LPDBs), each mapping control parameters to a geographic location and returning a location result when queried. One or more filters is applied to the control parameters that is received by the subscriber database, each filter selectively initiating processing using a LPDB appropriate to the task of the filter and to the current state of the device.
1 . Method for locating and tracking devices in a mobile telephone network comprising the steps of:
(a) receiving mobile telephone control parameters in a subscriber database;
(b) using one or more location parameter databases (LPDBs), each mapping control parameters to a geographic location and returning a location result when queried;
wherein one or more filters is applied to the control parameters that is received by the subscriber database, each filter selectively initiating processing using a LPDB appropriate to the task of the filter and to the current state of the device.
2 . The method of claim 1 wherein for at least one location parameter database a filter determines whether the location parameter database is supplied with control parameters.
3 . The method of claim 1 , wherein a filter observes changes in control parameters for a given subscriber or for members of a group of subscribers.
4 . The method of claim 3 , wherein a filter observes control parameters which relate to a particular geographical area of interest, using the lowest cost location parameter database.
5 . The method of claim 1 , wherein a filter chooses an appropriate location parameter database depending on whether a trigger condition is met.
6 . The method of claim 1 , wherein a filter chooses the location parameter database that offers the lowest computational cost.
7 . The method of claim 1 , wherein for a particular request, a location mechanism is chosen which has the least processing cost, but which can be expected to return a result of the necessary accuracy.
8 . The method of claim 5 wherein a trigger condition relates to a subscriber entering a defined area.
9 . The method of claim 5 , wherein a trigger condition relates to a subscriber leaving a defined area.
10 . The method of claim 5 , wherein if a trigger condition is not met, then the filter re-calculates after a time period that is a function of the estimated speed of the subscriber.
11 . The method of claim 1 , wherein the information from one location fix is used to restrict the possible locations of the next fix.
12 . The method of claim 5 , wherein if a trigger condition is met, then the filter causes an appropriate location parameter database to be supplied with control parameters and to return a geographic location of the associated subscriber.
13 . The method of claim 1 , wherein a filter invokes retrospective processing on stored subscriber database contents to discover where a subscriber entering a geographical area originated.
14 . The method of claim 1 , wherein a filter invokes retrospective processing on stored subscriber database contents to discover the history of a subscriber's activity.
15 . The method of claim 1 , wherein additional LPDBs with different cost trade-offs can be added to provide the system with more options.
16 . The method of claim 1 , wherein the subscriber database retains control parameter records for all subscribers on a network.
17 . The method of claim 1 , wherein a location parameter database uses RF levels.
18 . The method of claim 1 , wherein a location parameter database uses pairwise ratios.
19 . The method of claim 1 , wherein a location parameter database uses cell timing advance.
20 . The method of claim 1 , wherein a location parameter database uses cell identity.
21 . The method of claim 1 wherein a location parameter database uses GPS trace data fed back from a GPS device used by the subscriber
22 . The method of claim 1 , wherein when there is only partial coverage, the next higher accuracy LPDB is selected, or the most accurate lower accuracy LPDB available is selected.
23 . The method of claim 1 , wherein high accuracy tracking is achieved using an initial (cell, timing-advance) LPDB to identify candidate buckets in an RF LPDB.
24 . The method of claim 1 , wherein an origin trigger is triggered when a subscriber, or a member of a set of subscribers, leaves a defined geographical area, where the origin trigger is implemented using filters.
25 . The method of claim 1 , wherein a destination trigger is triggered when a subscriber, or a member of a set of subscribers, enters a defined geographical area, where the destination trigger is implemented using filters.
26 . The method of claim 1 , wherein proximity triggers monitor whether two subscribers are near to each another.
27 . The method of claim 1 , wherein a group of subscribers is defined automatically as the subscribers in a particular area at a particular time.
28 . The method of claim 27 , wherein when some members of the group appear in proximity once again, or enter another area with similar characteristics to the first area, the appropriate triggers will be invoked.
29 . The method of claim 1 , wherein a contact tree is generated using call records to discover the set of call recipients for a particular handset, or the set of callers to a particular handset.
30 . The method of claim 1 , wherein the method is used to determine the presence of a vehicle in a congestion zone.
31 . The method of claim 1 , wherein the method is used to determine the presence of a vehicle in road toll system or in a road usage pricing system.
32 . The method of claim 1 , wherein the method is used to determine the usage of vehicles on roads for insurance pricing.
33 . The method of claim 1 , wherein the method is used to locate and track mobile subscribers for governmental, regulatory and law enforcement purposes.
34 . The method of claim 1 , wherein the method is used to track vehicles in a fleet
35 . Apparatus which locates and tracks devices in a mobile telephone network comprising:
(a) a subscriber database which receives mobile telephone control parameters;
(b) one or more location parameter databases, each mapping control parameters to a geographic location and returning a location result when queried;
wherein one or more filters is applied to the stream of control parameters that is received by the subscriber database, each filter selectively initiating processing using a LPDB appropriate to the task of the filter and to the current state of the device.