Patent attributes
An SDH transmission apparatus including a low-speed part, a high-speed part, and a cross-connect part is disclosed. The low speed part includes a first signal transmission part and a second signal transmission part, each signal transmission part including an active transmission part and a standby transmission part. In the SDH transmission apparatus, an active transmission part of the first signal transmission part transmits a signal to a first transmission line via the high-speed part, an active transmission part of the second signal transmission part transmits a signal to a second transmission line via the high-speed part, and a standby transmission part of the first signal transmission part sends a part of signals supplied to the first signal transmission part to the second transmission line via the high-speed part when a traffic amount of the signals supplied to the first signal transmission part exceed a predetermined value.