Abstract: A bidirectional data communications distribution network is established between the system operations center (SOC) and customer terminals of a load management and electrical energy distribution system. The distribution network comprises independent processor controlled, primary communications interface units (PCI) in communication with the SOC over telephone lines or other medium. Each PCI is in turn in communication with a plurality of independent processor controlled, secondary communications interface units (SCI) over electrical utility primary distribution power lines. Signals between PCIs and SCIs on the primary distribution power lines are code division multiplexed using direct sequence spread spectrum (DSSS) signal processing. Each SCI continuously polls a number of assigned customer load terminals on the low voltage side of the electrical energy distribution system, storing and calculating meter register readings and load status.

Abstract: A plurality of transmitters synchronized to a common clock each transmit a data signal spread by a common bipolar pseudo-random code having a different assigned code sequence shift. A receiver, synchronized to the clock, discriminates the signal transmitted by a predetermined transmitter from signals transmitted by the others by generating a first bipolar pseudo-random code that is a replica of the common bipolar pseudo-random code and has a code sequence shift corresponding to that of the predetermined transmitter, and a second bipolar pseudo-random code that is a replica of the common bipolar pseudo-random code and has an unassigned code sequence shift. The difference between the first and second bipolar pseudo-random code sequences, which is a trinary code sequence, is cross-correlated with the incoming signals. The cross-correlation despreads only the signal spread by the sequence having the predetermined code sequence shift.