In addition, the husband may have a location-aware mobile phone.

The wife may use the car to drive to the wife's office, after giving the husband a ride to his office.

Then information from the mobile phone, indicating that the husband is at his office, will be inconsistent with information from the tracking device in the car, indicating that the husband is at the wife's office.

[0006] Such an inconsistency could cause significant, practical problems.

To continue the example, the husband's employer may use location information from employees' mobile electronic devices to determine the employees' location.

This system would help the employer make good decisions about dispatching employees to make sales calls or service calls.

However, this system could be defeated when information from one source indicates that the husband is at his office, and information from another source indicates that the husband is at the wife's office.

[0007] The inconsistency would be difficult to resolve, without additional information about the people involved, their schedules, and how they are associated with various mobile devices.

To make the best use of these positioning technologies, it would be important to make use of all available information, from multiple sources, to determine users' locations.

Thus there is a need for methods and systems that acquire, aggregate, and evaluate location information from multiple sources.

There is a need for methods and systems that go beyond just locating a mobile device, to also include information about people, their schedules, and their various devices.

[0008] The present invention is a system and method for handling location information.

If properly handled, such location information can be very useful.

One example, dispatching employees to make sales calls or service calls, was mentioned above.

The goal of the present invention is to allow users to collect and evaluate information from multiple sources, and thus make proper use of all available location information.

[0009] Without such a method or system, positioning technologies cannot properly handle multiple location sources for a single user, or a single location source shared by multiple users.

Without such a method or system, users would be left with the above-mentioned problem of location information from one source being inconsistent with information from another source

[0010] The solution is to make proper use of all available location information, by first collecting and then evaluating information from multiple sources.

Information from some sources generally would be more reliable than others.

For example, information from a device that is not shared may be more reliable than information from a device that is shared by more than one user.

Information from a device that recently changed position may be more reliable than information from a device that has not recently changed position.

[0011] Instead of merely locating a mobile device, the present invention locates people, i.e. users who may have more than one mobile device, and perhaps computerized calendars that indicate a person's expected location.

The electronic sources of location data (hereafter referred to as "location sources") for the present invention include mobile electronic devices such as mobile telephones, personal digital assistants, Global Positioning System (GPS) devices, and other pervasive computing devices.

Location sources also include computer-based models, schedules or calendars that give a person's expected location depending on the date and time.

These models, schedules or calendars may be stored on personal digital assistants, desk-top computers, or servers, for example.

[0012] After location information is acquired from location sources, a user who is tracking the locations of other users might evaluate the collected location information himself or herself, or evaluation could be automated.

In a fully automated system, a computer would perform ranking or filtering operations on the data before providing the information to the user.

[0013] One aspect of the present invention is a method for handling location information.

Another aspect of the present invention is a system for executing the method of the present invention.

A third aspect of the present invention is as a set of instructions on a computer-usable medium, or resident in a computer system, for executing the method of the present invention.