| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a line quality monitoring system for monitoring a quality of a line between transmission apparatuses at all the time. <P>SOLUTION: The line quality monitoring system comprises: a first main signal inspection means that is provided in a first transmission apparatus for inspecting normality of a main signal received from a host device; a transmission means that is provided in the first transmission apparatus for producing a line monitoring signal and transmitting the signal to a second transmission apparatus if no main signal is received from the host device for a predetermined time; a second main signal inspection means that is provided in the second transmission apparatus for inspecting normality of a main signal received from the first transmission apparatus; a line monitoring signal inspection means that is provided in the second transmission apparatus for inspecting normality of the line monitoring signal received from the first transmission apparatus; and an alarm means that is provided in the second transmission apparatus for determining frequency of abnormality detection by the second main signal inspection means and the line monitoring signal inspection means and issuing an alarm if the frequency exceeds a threshold which is held in advance. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
