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:
Sep. 22, 1992
Filed:
Apr. 10, 1990
Tho Autruong, Mountain View, CA (US);
Daniel Lai, Los Altos, CA (US);
Rolm Systems, Santa Clara, CA (US);
Abstract
Method and apparatus for minimizing retransmissions during communication in a modem-to-modem communications system. The inventive method includes the steps of: (a) receiving a data packet and determining a checksum; (b) comparing the checksum with a checksum embedded in the data packet; (c) if the checksums are the same, transmitting a signal which indicates that the data packet was received correctly and returning to step (a); (d) if the checksums are different, incrementing a counter; (e) checking the counter, if the counter is less than a predetermined threshold, saving the data packet with its embedded checksum, transmitting a signal which indicates that the data packet was not received correctly and returning to step (a); (f) otherwise, bit averaging the newly received data packet with previously received and stored data packets, including the embedded checksums, and determining a checksum for the bit averaged data packet; (g) if the bit averaged, embedded checksum matches the determined checksum for the bit averaged data packet, transmitting an 'OK' signal and returning to step (a); and (h) if the bit averaged, embedded checksum does not match the determined checksum for the bit averaged data packet, saving the newly received data packet with its embedded checksum, transmitting a signal which indicates that the data packet was not received correctly and returning to step (a).