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:
Jul. 14, 1987
Filed:
Oct. 01, 1984
Clifford A Davidow, Reno, NV (US);
Lynch Communication Systems, Inc., Reno, NV (US);
Abstract
Malfunctions in an automatic span line switch due to resonances in high-speed span lines are avoided by interposing signal-free intervals whenever the switch causes a possible phase change to occur in the signal being supplied to the span, preventing the transmission of partial signal pulses, and using quasi-random code and keep-alive signals. Unnecessary phase changes are avoided by verifying the validity of data before allowing it to be put on the span following a data loss; disabling the error detection circuitry for a limited time following a switching operation; and preventing the switching of low-priority span on standby if the failure has been remedied during the standby period. In other aspects of the invention, the switch is made adaptable to various types of high-speed spans and to a wide range of quality requirements by allowing for individual adjustment of loss-of-signal time, burst protection time, error count, and bit count for failure and restoral detection, and by selectively allowing different types of errors to be detected. Finally, backup due to one-sided restoral is eliminated by refailing a restored switch if its mate does not restore.