Patent ID: 7369764
Filing Date: 2008-05-06
Classification: H04B

Abstract:
1. A transmission line monitoring apparatus monitoring faults occurring in a transmission line and/or in an apparatus which are connected with the transmission line, said transmission line monitoring apparatus comprising: a first optical coupling unit which couples a down data signal of a first wavelength and an examination signal of a second wavelength so as to transmit a first coupled signal to a lower apparatus; a first optical dividing unit to demultiplex said first coupled signal from said optical coupling unit so as to divide and split said first coupled signal into said down data signal with the first wavelength and said examination signal with the second wavelength, said examination signal being returned; a second optical coupling unit which couples an up data signal with the first wavelength and said returned examination signal from said first optical dividing unit so as to transmit a second coupled signal toward a host apparatus; a second optical dividing unit to demultiplex said second coupled signal from said second optical coupling unit so as to divide and split said second coupled signal into said up data signal with the first wavelength and said returned examination signal with the second wavelength; and a monitoring unit which monitors a fault and an exact location of said fault by using said examination signal with the second wavelength and indicates said exact location of whether said fault occurs in the transmission line, the lower apparatus or the host apparatus, and where said first optical coupling unit, said first optical dividing unit, said second optical coupling unit and said second optical dividing unit are formed of passive elements that are operable without a power supply.