05938721 is referenced by 722 patents and cites 12 patents.

A task description is stored in a database accessible by a mobile computer system. The mobile computer system receives positioning information corresponding to its geographic location and indexes the database based on the positioning information when the information indicates that the mobile computer system is in a geographic location that facilitates completion of a task associated with the task description. The database may be resident in the mobile computer system or accessible in other ways, for example, via the Internet. The task description preferably includes a geocode which corresponds to the geographic location at which completion of the task may be facilitated. The task description may also include textual, voice or other message which can be displayed and/or played back to a user. The positioning information may be obtained from a GPS satellite, a GLONASS satellite or a pseudolite. The mobile computer system may be a portable unit, such as a PDA, or integrated within a vehicle.

Title
Position based personal digital assistant
Application Number
8/738983
Publication Number
5938721
Application Date
October 24, 1996
Publication Date
August 17, 1999
Inventor
David J Cowl
Sunnyvale
CA, US
John F Schipper
Palo Alto
CA, US
James M Janky
Los Altos
CA, US
William O Dussell
Pescardero
CA, US
Agent
Blakely Sokoloff Taylor & Zafman
Assignee
Trimble Navigation
CA, US
IPC
G06F 165/00
G01C 21/00
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