Abstract: A cable television (CATV) system is modified to provide two-way telephone communications in a subsplit band below the video signal, preferrably in the range of approximately 5-40 MHz. Each line amplifier in the coaxial cable network is equipped with a bypass strap or bypass circuitry to maintain a signal path through the line amplifier for the telephone signal in the event of failure of the line amplifier. Due to the decreased attentuation resulting from its lower frequency, the telephone signal can typically travel the distance of three or four line amplifier spacings without amplification. Line amplifier failure is a common occurrence in CATV networks. Therefore, the present invention greatly increases the reliability of telephone communications over CATV networks.

Abstract: A method of providimg two-way communication between a plurality of channel units in a channel bank and a line interface circuit of a telephone system utilizing a receive direction protocol and a separate transmit direction protocol. The receive direction protocol identifies the channel unit to which provisioning data is to be delivered, increases the bandwidth of the voice data region in the time slot corresponding to the identified channel unit, superposes the provisioning data in the time slot with the voice data, and delivers the superposed data to the channel unit wherein the provisioning data is separated from the voice data. The transmit direction protocol utilizes the A and B signaling bits corresponding to the eighth bit of an identified time slot in the sixth and twelfth transmit frames wherein two bits of an eight bit status message is delivered on every other superframe. The two-way communication protocols occur without affecting or interfering with the PCM voice data.