73100590
Sep 21, 1976
Jun 27, 1978
DIGITAL COMMUNICATION SYSTEMS-NAMELY, DIGITAL REPEATERED LINE TRANSMISSION APPARATUS, HIGH CAPACITY DIGITAL TRANSMISSION APPARATUS, VOICE FREQUENCY CARRIER TELEGRAPH APPARATUS, COMMUNITY DIAL OFFICE EQUIPMENT, LOCAL TOLL DIGITAL SWITCHING OFFICE EQUIPMENT, TOLL SWITCHING DIGITAL NETWORKS, DATA SWITCHES AND DIGITAL MICROWAVE TRANSMISSION APPARATUS
Electrical and Scientific Apparatus