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. 01, 1977
Filed:
Jan. 29, 1976
Joseph Henry Condon, Summit, NJ (US);
Robert Bruce Kieburtz, Fair Haven, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
An elastic interface is disclosed for two communicating digital carrier systems autonomously synchronized to disparate time bases independent of each other in frequency and phase. The interface includes two arrangements, one for each direction of transmission between the two digital systems. In an illustrative application for the interface in a telephone system, the first of the two digital systems is a digital transmission system while the second is a time-division-multiplex switching network. The different internal constraints of each system call for digital signals at variance in sampling rate and code format. The interface amply satisfies the difference in sampling rate by an interpolation process which supplies the requisite number of intermediate encoded signal samples. Code conversion techniques are employed to match the code format of each digital system. Flexibility in the interpolation process is provided by adjusting the value of the encoded samples in response to changes in the relative time intervals between each encoded sample being supplied to one digital system and the encoded samples from the other digital system upon which it is derived. The digital signal medium established in the interface preserves the quality of the information traversing the medium as the digital signals coupled thereto undergo a change in sampling rate even though the autonomous operation of each of the two digital systems occasions relative frequency drift between the time bases of the two digital systems.