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:
Jan. 04, 2005
Filed:
Oct. 29, 1999
Gordon Taylor Davis, Chapel Hill, NC (US);
Ajay Dholakia, Gattikon, CH;
Dongming Hwang, Cary, NC (US);
Malcolm Scott Ware, Raleigh, NC (US);
Hua YE, Durham, NC (US);
Gordon Taylor Davis, Chapel Hill, NC (US);
Ajay Dholakia, Gattikon, CH;
Dongming Hwang, Cary, NC (US);
Malcolm Scott Ware, Raleigh, NC (US);
Hua Ye, Durham, NC (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Digital impairments, including Robbed Bit Signaling (RBS) and impairments due to digital attenuation PAD (Packet Assembler/Disassembler) devices, may be identified in sets of Pulse Code Modulation (PCM) signal levels, such as sets of Digital Impairment Learning (DIL) signals transmitted from a server modem to a client modem during a plurality of DIL levels. Both signature analysis and signal level comparison analysis are preformed on the signals to identify digital impairments. Signature analysis compresses the set of signal levels into a signature. Digital impairments are determined based on the signature. In a preferred embodiment, the PCM signal levels are compressed into a signature by identifying clusters and/or skips. PCM signal level comparison analysis uses differences, between PCM signals and models of signals having various digital impairments. By using both techniques combination, the strengths of each technique are utilized while the weaknesses of each techniques are avoided.