A space and time switch receives digitized voice and/or data as twenty-two separate serial bit streams with each voice or data path occupying one time-slot on one bus, resulting in a total of 704 paths entering the switch. The switch originates twenty-two buses and the information in any incoming path...http://www.google.com/patents/US4809261?utm_source=gb-gplus-sharePatent US4809261 - Space and time switch for 22 PCM highways
