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. 19, 1991
Filed:
Jul. 31, 1989
Applicant:
Inventors:
Assignee:
GEC Plessey Telecommunications Limited, Coventry, GB;
Primary Examiner:
Int. Cl.
CPC ...
H04K / ; H04K / ; H04M / ;
U.S. Cl.
CPC ...
380 23 ; 379 62 ; 455 33 ; 455 34 ;
Abstract
The method comprises transmitting an initiating signal in the form of a bit pattern as a continuous burst from one radio unit to the other. The pattern incorporates a preamble pattern and a security code having a plurality of bit sequences. Each sequence is transmitted a number of times. The received security code is compared with stored codes in the other unit, and if a matching pair is identified a response signal is transmitted from the other unit to said one unit. The response signal incorporates the preamble pattern for establishing synchronization between the radio units.