Patent ID: 8989063
Filing Date: 2015-03-24
Classification: H04B,H04J,H04M

Abstract:
1. A digital subscriber line access multiplexer (DSLAM) configured to couple to a first subscriber line and a second subscriber line, the DSLAM comprising: a processor configured to allocate a plurality of time slots for downstream far-end crosstalk (FEXT) channel estimation, wherein the plurality of time slots comprises a first period and a second period, wherein the first period precedes the second period, and wherein each of the first and second periods comprises at least one time slot; a transmitter coupled to the processor and configured to transmit at least one training symbol in the first period onto the second subscriber line while no transmission is made on the first subscriber line; and a receiver coupled to the processor and configured to receive at least one feedback symbol in the second period from the first subscriber line, wherein the processor is further configured to estimate a level of downstream FEXT from the second subscriber line into the first subscriber line based on the at least one feedback symbol, wherein the first subscriber line is a showtime line, wherein the second subscriber line is a joining line, and wherein no transmission is made on the second subscriber line in the second period.