Patent ID: 8792620
Filing Date: 2014-07-29
Classification: H04B,H04M

Abstract:
1. A method comprising: transmitting a probing signal on the twisted pair telephone line from a Digital Subscriber Line (DSL) device coupled to the line, wherein the probing signal is transmitted in a frequency used for upstream data transmission or downstream data transmission in a DSL system that employs frequency-division duplexing of upstream and downstream data transmission, in one of an upstream direction from a customer premises location or a downstream direction from a central office location, during one of a DSL data transmission period or DSL sync symbol transmission period; receiving the probing signal reflected on the twisted pair telephone line at the DSL device; removing an estimate of one of a DSL data transmission signal or DSL synch symbol transmission signal from the received probing signal to recover the reflected probing signal; and processing the recovered reflected probing signal to determine characteristics information of the twisted pair telephone line.