Bandspread communication network system in low-voltage distribution network and its communication method

The present invention belongs to the field of low-voltage power line communication technology. The bandspread communication network system features the pyramid-shaped master-slave communication system structure comprising computer, concentrator, router and subscribers from top to down. The communication method features the establishment of relation table of network node low-place address and phase on the basis of proposing network node and network segment; the establishment of the bi-directional communication relationship including concentrator, network segment router, network node low-place address and phase; and the establishment of the subscriber ID-network node address table for unique correspondence of subscriber ID and destination address.