Allan M Hofmann

40028410, Jan 11, 1977

Jan 21, 1976

5/650936

Allan Michael Hofmann - Jackson NJ
David Gavin Messerschmitt - Middletown NJ

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

H04J 602

179 15AS

A digital speech interpolation (DSI) system advantageously utilizes speech inactivity time to reduce the bit rate by compressing digital characters from a plurality of trunks onto a lesser plurality of channels. A signaling arrangement is typically employed therein to signal a receiver as to the activity of a trunk. If the number of active trunks exceeds the number of channels, an overload may exist. Known arrangements for mitigating overload typically include apparatus responsive to an activity signal for truncating one or more bits from the digital characters and for transmitting the truncated characters. Unfortunately, quantization noise is increased and digital precision decreased in such arrangements. The hereindisclosed system includes an improved automatically adaptive arrangement for advantageously incorporating nearly instantaneous companding (NIC) and priority trunk rotation in a plurality of frames, called a multiframe. Thereby, a mitigation of overload as well as a lessening of quantization noise relative to known DSI arrangements is attained.

40950530, Jun 13, 1978

Sep 1, 1977

5/829664

Donald Lars Duttweiler - Colts Neck NJ
Allan Michael Hofmann - Jackson NJ

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

H04J 306

179 15AF

In a digital communication system, synchronization of a plurality of asynchronous digital signals is usually achieved by stuffing one or more pulses in a pulse stream. Thereby, stuffing equalizes the input signal bit rate with the usually fixed bit rate of a signal on a transmission link. For example, in pulse stuffing, single pulses are added at certain allowed times to equalize the input bit rate with the transmission link bit rate. On the other hand, in block stuffing, a block of pulses is added. However, conventional block stuffing usually requires a narrowband phase-locked loop for removing jitter in the received signal. As a result, slower acquisition of synchronization occurs. To mitigate this and other problems in a block oriented system, an improved arrangement, called quasi-pulse stuffing synchronization, employs block stuffing at a transmitter and pulse destuffing at a receiver in combination with a control signal for identifying when a digital signal would have been pulse stuffed if the system were employing pulse stuffing. Thereby, jitter can be removed using a conventional widerband, pulse stuffing phase-locked loop.