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. 02, 2003
Filed:
Jan. 20, 1999
Ajay Gummalla, Atlanta, GA (US);
Sunil Khaunte, Santa Clara, CA (US);
Cisco Technology, Inc., San Jose, CA (US);
Abstract
A technique is provided for dynamically adjusting modem back-off parameters in a cable modem network. The technique is based on the theoretical result that the ratio of the number of the successful band width requests (Ns) to the number of collisions (Nc) has a value (e-31) when the back-off values are correctly estimated. The present technique for dynamically adjusting modem back-off parameters utilizes this concept to correspondingly correct the back-off parameters, depending upon the value of the Nc/Ns ratio, so as to cause this ratio to converge to the desired ratio of Nc/Ns equal to approximately 0.7. If the ratio of Nc/Ns is greater than a first specified value, the back-off start and backoff-end parameters (broadcast by the CMTS to cable modems on the downstream channel) are increased. If the ratio of Nc/Ns is less than a second specified value, the back-off start and backoff-end parameters are decreased. The present technique provides for improved access delay and improved throughput performance in contention sub-channels of cable access networks, particularly those involving large round trip delays. Additionally, the technique of the present invention utilizes elementary CPU operations, making it a viable and cost-efficient solution which is easily implemented and allows for rapid execution in existing cable modem network systems. Furthermore, the technique of the present invention is able to track the number of contending cable modems in a network over a much larger range than previous techniques.