COMMUNICATION JAMMING METHOD AND APPARATUS THEREOF, AND PROPAGATION DIRECTION DETERMINING METHOD AND APPARATUS THEREOF

摘要

PPROBLEM TO BE SOLVED: To jam communication of an unidentified PLC modem. PSOLUTION: A communication jamming device 30 is connected to two power source outlets 14a, 14b nearest to a connector of a branch power line 14 to a high-order power line 10. Power source plugs 32, 36 are connected to the outlets 14a, 14b, respectively. A PLC communication detector 34 detects the PLC communication signal of the outlet 14a, and a PLC communication detector 38 detects the PLC communication signal of the outlet 14b. A differential amplifier 40 output a signal indicating a difference in output between the apparatuses 34 and 38. A direction determining apparatus 42 determines whether the PLC communication signal on the power line 14 is in an upward direction from the output of the differential amplifier 40. If it is in the upward direction, the apparatus 42 applies an activation signal for generating a jamming signal to a jamming signal generating apparatus 44. The apparatus 44 generates a jamming signal of a predetermined period in accordance with the activation signal, and applies it to the power line 14. PCOPYRIGHT: (C)2007,JPO&INPIT