73826251
Sep 18, 1989
May 8, 1990
MODEMS WITH FREQUENCY SHIFT KEYING CAPABILITY THAT USES ALTERNATING CURRENT POWER WIRING CONTAINED IN A COMMERCIAL OR RESIDENTIAL BUILDING AS A MEDIUM FOR TRANSMITTING DATA COMMUNICATION SIGNALS, AND THAT EMPLOYS STANDARD FREQUENCY MODULATION COMMUNICATION TECHNIQUES AND OPERATING SYSTEM COMPUTER PROGRAMS AS RELIABILITY ENHANCING FEATURES
Electrical and Scientific Apparatus