公开(公告)号：US3978449A

公开(公告)日：1976-08-31

申请号：US544207

申请日：1975-01-27

Applicant: Ray W. Sanders ,  Neil T. Keyes ,  Stephen W. Harting ,  Donald J. Mueller

Inventor： Ray W. Sanders ,  Neil T. Keyes ,  Stephen W. Harting ,  Donald J. Mueller

IPC: H04L1/00 ,  G06F11/08 ,  G06F13/00 ,  H04L12/00 ,  H04L25/49 ,  H04L29/06 ,  H04L29/14 ,  H03K5/18 ,  H04L1/08

CPC classification number: H04L12/00

Abstract: An in-band signalling system for the transmission of both data and control signals through a common communications channel is disclosed. Unique means of distinguishing data bits from control bits is employed without the use of additional bandwidth over that which would be required for the data alone.A novel method for signalling includes the steps of translating the data bits into a different code set than the original, examining it for control words and if any are present, modifying or corrupting the data and thereafter combining on a time division basis the translated and/or modified data and control words over a transmission channel. To receive, data is inversely modified and control words detected. Error detection of control words is achieved by translating control words followed by their complements.