Digital subscriber line communicating system

A digital subscriber line communicating system having a central office and a remote terminal connected through a telephone line, the transmitting side comprising a sliding window transmitting unit for transmitting DMT symbols according to the sliding window through the telephone line to the receiving side, and the receiving side comprising a sliding window receiving unit for receiving DMT symbols according to the sliding window from the transmitting side, the sliding window indicating the cross-talk condition (NEXT,FEXT) due to an adjacent TCM-ISDN transmission at the receiving side, whereby cross-talk can be reduced by synchronizing the transmitting sliding window with said NEXT and FEXT statuses.