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:
Nov. 30, 2004
Filed:
Sep. 11, 1998
Russell P. Cashman, Vista, CA (US);
Richard A. Schwartz, San Diego, CA (US);
Pacific Communication Sciences, Inc., Austin, TX (US);
Abstract
A portable communications subscriber unit operates as a data transfer terminal as well as an analog cellular telephone M-ES. Two modes of operation, an analog cellular communication mode and a Cellular Digital Packet Data (CDPD) mode, are available in the subscriber unit. The subscriber unit distinguishes between paging signals indicative of a CDPD mode of communication and those indicative of an analog cellular mode of communication. The subscriber unit automatically preempts CDPD communications in favor of analog cellular communications such as those carried out in an AMPS system. The present inventive method enables the subscriber unit to remain registered in the CDPD communication system using a CDPD “sleep mode” while performing activities on the AMPS system. Another aspect of the present invention facilitates the automatic switching of subscriber unit displays to correspond to the communication system with which the unit is presently communicating.