Network of intelligent devices communicating via powerline and radio frequency
View Patent ↗Low-cost intelligent control and communication devices are arranged to communicate with one another over one or more shared physical media, such as a powerline or a radio frequency band. No network controller is needed, because any device can act as a master, slave, or repeater. Adding more devices makes the system more robust, by virtue of a simple protocol for communication retransmissions and retries.
1. A communication module for use in a system including a plurality of said communication modules, said communication module comprising:
circuitry for sending and receiving messages in fixed time slots over a mains power line;
circuitry and software for generating said messages and for receiving and deciphering said messages;
each of said messages having a plurality of signal packets, wherein each of said signal packets is synchronized with a zero crossing of an alternating voltage on the mains power line;
circuitry and software for retransmitting a received one of said messages beginning at a multiple of said time slot; and
circuitry and software for retransmitting a message during the same time slot as other of said communication modules are retransmitting the message over the mains power line.
2. The communication module of claim 1 including an RF transceiver enabled for sending and receiving messages via radio transmission, and comprising circuitry and software for retransmitting a message via radio transmission beginning at a zero-crossing of a mains power line voltage following reception of the message via the mains power line.
3. The communication module of claim 2 comprising circuitry and software for transmitting messages via radio transmission during the same time slot as other of said communication modules are sending identical messages via radio transmission.