Abstract: The present invention describes an FSK carrier communication systems for transmitting and receiving data on a electric utility line even in the presence of extreme noise. The present invention uses a unique FSK transmit and receive protocol to distinguish between noise and actual data. By careful selection of the space and mark frequencies transmitted on the power line and by using a unique variable width data-bit protocol, the receiver can distinguish between actual data and corrupted information due to noise spikes with nearly error free communication.

Abstract: A utility meter reading and communications system gathers data from utility meters and sends that data to a utility company's central data collection point (host computer) via phone lines. The system places a call on the user's telephone line at a specified time and date and transmits data using dual-tone multifrequency (DTMF) format. The system ensures that users still may use the telephone line by sensing off-hook conditions initiated by a resident's telephone and immediately dropping the line to reestablish dial tone for the residential customer. The system uses a variety of error-detection procedures and communications protocols to ensure a high degree of reliability in communicating data to and from the central office and the utility meter system. The system also uses communications protocols and handshaking to ensure accurate data communication and allow immediate interruptions of communications should the customer attempt to use the telephone line.