U.S. Philips Corporation

Hans-Dieter Kauschke

Dieter Schwarz

It is known in the art to characterize, by means of special bits in the time-division multiplex signal frame, transmission paths in a PCM transmission system which do not convey a useful signal, or to refrain from transmitting a signal through a non-occupied transmission path. To prevent the necessity of resolving the frame structure down to the bit plane for enabling recognition of the identification of non-occupied and undisturbed transmission paths, a digital signal pattern is used which is periodical, is distributed over the time-division multiplex frames and cannot be simulated by frame alignment of system alarm words nor by the useful information. If more specifically the inverted version of the standardized alarm-indication-signal AIS is used as the digital signal pattern, then the additional circuit cost and design effort in realizing arrangements for producing and recognizing this pattern is very low because of the fact that AIS-generators and AIS-recognition circuits already present in existing equipment can be utilized very efficiently in such a realization.

Arrangements for producing and recognizing information identifying

Arrangement for producing and recognizing information identifying non-occupied transmission paths in a digital transmission system. It is known in the art to characterize, by means of special bits in the time-division multiplex signal frame, transmission paths in a PCM transmission system which do not convey a useful signal, or to refrain from transmitting a signal through a non-occupied transmission path. To prevent the necessity of resolving the frame structure down to the bit plane for enabling recognition of the identification of non-occupied and undisturbed transmission paths, a digital signal pattern is used which is periodical, is distributed over the time-division multiplex frames and cannot be simulated by frame alignment of system alarm words nor by the useful information. If more specifically the inverted version of the standardized alarm-indication-signal AIS is used as the digital signal pattern, then the additional circuit cost and design effort in realizing arrangement for producing and recognizing this pattern is very low because of the fact that AIS-generators and AIS-recognition circuits already present in existing equipment can be utilized very efficiently in such a realization.

Growing community of inventors

Nuremberg, Germany

Hans-Dieter Kauschke