An electronic telephone exchange of the type employing time-space-time switching, has an optical fiber data link connecting the space and time switches. In order to meet the design requirements for use in a telephone exchange, the fiber optic link has to have fairly well defined performance parameters....http://www.google.com/patents/US4468765?utm_source=gb-gplus-sharePatent US4468765 - Electronic telephone exchanges and optical fiber links for use therein
