Accession Number : ADA183476

Title :   Error Control Option for Group 3 Facsimile Equipment.

Descriptive Note : Final rept.

Corporate Author : DELTA INFORMATION SYSTEMS INC HORSHAM PA

PDF Url : ADA183476

Report Date : Feb 1987

Pagination or Media Count : 64

Abstract : Group 3 facsimile equipment, which meets CCITT Recommendations T.4 and T.30 (Federal Standards 1062 and 1063, respectively), is now used extensively throughtout the world and throughout the U.S. Government. This equipment has no error control capability; the output image quality and transmission bit rate are totally dependent upon the communication circuit during the message transmission period. There are two basic categories of error control schemes for data communications: automatic-repeat-request (ARQ) schemes and forward-error-correction (FEC) schemes; in this report, several algorithms of each type are evaluated, as well as several hybrid algorithms in which characteristics of both schemes are employed. The purpose of this study was to determine the feasibility of an error control option for the Group 3 facsimile standard, which would increase the reliability of transmission over the public switched telephone network (PSTN).

Descriptors :   *ALGORITHMS, *DATA TRANSMISSION SYSTEMS, *HYBRID SYSTEMS, *TELEPHONE SYSTEMS, *COMMUNICATION AND RADIO SYSTEMS, CONTROL, ERRORS, PUBLIC UTILITIES, SWITCHING, CIRCUITS, CONTROL, IMAGES, OUTPUT, QUALITY, RELIABILITY, TRANSMITTANCE

Subject Categories : Command, Control and Communications Systems

Distribution Statement : APPROVED FOR PUBLIC RELEASE