International Telephone and Telegraph Corporation

James H Bowen

Philip R Couch

David L Baldwin

A time division multiplex digital data communication system with reduced band width. The system operates on independent digital signals so they can be multiplexed by encoding the time of transition of the digital data on each channel and transmitting serially the encoded times along with a bit for indicating the direction of transition or state after the transition plus bits for synchronization and/or overhead, as necessary.

TDM Communication system

A fiber optic data transmission system is protected against external physical intrusion by obscuring the data in the natural quantum noise and then limiting access to the intruder by means of an optical power alarm. This is accomplished by modulating the data on a very large predetermined average optical power with a very small modulation index and then providing an alarm arrangement which is responsive to the received optical energy to activate an alarm means and to deactivate its associated transmitting arrangement when the received optical energy has an amplitude outside of a given amplitude region.

Growing community of inventors

Williamsburg, VA, United States of America

James H Bowen