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. 26, 2019
Filed:
Jul. 25, 2018
Bcs Access Systems Us, Llc, Wilmington, DE (US);
Xing Ping Lin, West Bloomfield, MI (US);
BCS ACCESS SYSTEMS US, LLC, Wilmington, DE (US);
Abstract
A passive keyless entry system for an electronic lock, comprises a lock installation including a lock controller, and an RF transmitter and receiver, and a fob with a controller, and an RF transmitter and receiver. The fob generates messages to unlock the lock in an unlock event. The controllers share a secret specifying parameters for a sequence of messages to be exchanged bidirectionally between the installation and the fob, the parameters changing between each unlock event and an immediately subsequent unlock event. For each unlock event one of the controllers generates and sends a first message of the message sequence, in accordance with the specified parameters. The other controller causes transmission of a second message of the sequence in accordance with the specified parameters, in response to receiving the first message. At least one message of the sequence comprises a plurality of frames, each frame including a particular sequence of bits, adjacent frames being separated by an inter-frame interval. Adjacent messages in the sequence being separated by an inter-message interval. The specified parameters are such that a given message of the sequence includes a first inter-frame interval, and the inter-message interval between said given message of the sequence and the immediately preceding or immediately subsequent message is no longer than said first inter-frame interval.