The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 11, 2000
Filed:
Aug. 23, 1995
Doron Ben-Yehezkel, Los Angeles, CA (US);
James E Forman, Westchester, CA (US);
John A Baker, Playa del Rey, CA (US);
Teletrac, Inc., Carslbad, CA (US);
Abstract
A method and system for providing location-based information services to a requesting user. A subscriber unit transmits an access request message comprising an identification number to one or more receiving sites on a response channel. A forward channel message is sent to the subscriber unit, the forward channel message comprising the identification number of the subscriber unit and data defining the time slot for transmission of a response message. A response message comprising an information service request and a location signal is transmitted from the subscriber unit and received at at least three receiving sites during the time interval identified by the forward channel message. The time difference of arrival of the location signal is used to determine the location of the subscriber unit. Thereafter, an information service message is generated which is responsive to the information service request and the location of the subscriber unit and transmitted to the subscriber unit on the forward channel. The step of generating the information service message comprises the steps of creating a database request from the information service request and the subscriber unit location, receiving database information response to the database request and the subscriber unit location, and processing and combining the database information to produce an information service message.