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:
Feb. 09, 1993
Filed:
Mar. 27, 1991
Steven T Barrett, Plantation, FL (US);
Kevin M Laird, Haltom City, TX (US);
Richard E Murray, Coral Springs, FL (US);
James M O'Connor, N. Richland Hills, TX (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A trunked communication system (400) transmits and receives encrypted signals over the system control channel (402). The trunked system (b 400) includes a plurality of radios (300) which can communicate with the communication system via control channel (402). By using control information signals and system information signals radios (300) can determine if it they are capable of decrypting the encrypted control information signals sent over the control channel (402). This is done by first determining if the encryption identification field found in the unencrypted system information signal matches an encryption identification field found in radio (300). If a match is found between the radio's encryption identification and the encryption identification field in the system identification signal radio (300) loads the encryption into the encryption circuitry in order to successfully decrypt the control information signals.