| 摘要 |
PURPOSE: A reverse ring signal removing apparatus of an optic transmission system is provided to detect and remove a reverse ring signal generated by an on-hook operation of a subscriber's terminal. CONSTITUTION: A subscriber unit(4) of a COT(Central Office Terminal)(3) changes a call processing signal inputted from an exchange into an optic signal and then outputs the changed signal through an optic cable(2). A subscriber unit(7) of an RT(Remote Terminal)(6) transmits the call processing signal inputted from the COT(3) through the optic cable(3) to a subscriber terminal(5). The subscriber unit(4) of the COT(3) includes a relay signal unit(8) for detecting ring/tip signal inputted from the exchange. A COIC(Central Office Interface)(9) produces and outputs a digital ring signal according to the ring/tip signal detected by the relay signal unit(8). A power unit(10) supplies a ring voltage signal to the COIC unit(9). An FPGA(Field Programmable Gate Array) unit(11) mixes the digital ring signal, changes the mixed signal into 155M OPTIC and transmits. A signal multiplex unit(12) is included to an inside of the FPGA unit(11) and removes a reverse ring signal generated to the COIC unit(9). |
