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:
Jun. 25, 1991
Filed:
Nov. 09, 1989
Thomas M O'Dell, Longmont, CO (US);
Ricky L Overmyer, Golden, CO (US);
AT&T Bell Laboratories, Holmdel, NJ (US);
Abstract
To provide robustness within the SMSI data communication protocol, a voice message system stores all message-waiting update (MW) messages that it sends to a communication switching system, and periodically transmits a properly-formatted MW message bearing intentionally-corrupted data to the switching system over their connecting data link. After each transmission the voice message system awaits the return on the data link of an invalid message-waiting (IMW) message. If the IMW message is returned within a predetermined time period following transmission of the corrupted MW message, the voice message system treats the data link as viable and clears the stored MW messages. If the IMW message is not returned within the predetermined time period following transmission of each of two corrupted MW messages, the voice message system treats the data link as not viable and, following repair of the link, re-sends the stored MW messages to the switching system.