Apparatus for providing loopback of signals where the signals being looped back have an overhead data format which is incompatible with a high speed intermediate carrier overhead format

Granted: Nov 5, 1985 Filed: Mar 19, 1984

This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.