Joseph A Sciulli

US Patent:

39886743, Oct 26, 1976

Filed:

Mar 17, 1975

Appl. No.:

5/559206

Inventors:

Joseph Albert Sciulli - Rockville MD

Assignee:

Communications Satellite Corporation (Comsat) - Washington DC

International Classification:

H04J 306

US Classification:

179 15BS

Abstract:

Bit rate compression in a digital communications system is provided by transmitting voice information from n telephone circuits over the capacity conventionally allocated for transmission of voice information from n/2 circuits without appreciable degradation in quality. Alternatively, a doubling of the number of voice circuits may be provided with transmission at the same bit rate required for conventional digital transmission of voice information. Each frame period, at the transmitter, all n circuits are serviced and, utilizing a predictive encoding scheme, only unpredictable samples in the given frame are transmitted over the available channel capacity. A sample assignment word (SAW), which identifies the circuits corresponding to the unpredictable samples, is transmitted therewith. Upon reception of the transmitted frame comprising the SAW and the unpredictable samples, the receiver updates the stored samples which were transmitted during previous frames as unpredictable samples by substituting the received unpredictable samples for the stored samples in accordance with the channel routing information provided by the transmission capacity conventionally allocated for transmission of digital voice information from the SAW, thereby enabling proper reconstruction of all samples in the given frame. Means are provided for effectively recirculating the servicing sequence of the n circuits to alleviate "overload.

US Patent:

39977293, Dec 14, 1976

Filed:

Jul 25, 1975

Appl. No.:

5/599228

Inventors:

Rene Costales - Rockville MD
Joseph Albert Sciulli - Rockville MD

Assignee:

Communications Satellite Corporation (Comsat) - Washington DC

International Classification:

H04J 602

US Classification:

179 15AS

Abstract:

Bit rate compression in a digital communications system is provided by transmitting voice information from n telephone circuits over the capacity conventionally allocated for transmission of voice information from n/2 circuits without appreciable degradation in quality. Alternatively, a doubling of the number of voice circuits may be provided with transmission at the same bit rate required for conventional digital transmission of voice information. Each frame period, at the transmitter, all n circuits are serviced and, utilizing a predictive encoding scheme, only unpredictable samples in the given frame are transmitted over the available channel capacity. A sample assignment word (SAW), which identifies the circuits corresponding to the unpredictable samples, is transmitted therewith. Upon reception of the transmitted frame comprising the SAW and the unpredictable samples, the receiver updates the stored samples which were transmitted during previous frames as unpredictable samples by substituting the received unpredictable samples for the stored samples in accordance with the channel routing information provided by the transmission capacity conventionally allocated for transmission of digital voice information from the SAW, thereby enabling proper reconstructions of all samples in the given frame. A pseudo-random priority sequencing system is provided for effectively recirculating the servicing sequence of the n circuits to alleviate "overload".