A bottleneck appears when conventional Optical Time Domain Reflectometer(OTDR) technology is used to monitor various branches of the Passive Optical Network(PON)
a point-to-multipoint optical access technology.In this paper
on the basis of analyzing the shortcomings of several existing solutions
a novel scheme is presented
in which each ONU-line is selected and tested by driving optical switch installed in ODN and powered by light-supply installed in OLT.