Patent ID: 7002969

Claim:
An STS frame-ATM cell circuit emulation apparatus for cellularizing an STS-(N×M) frame formed by multiplexing M STS-N frames formed from different channels into ATM cells and multiplexing M different STS-N frames assembled from ATM cells into an STS-(N×M) frame, comprising: circuit termination means for inputting and outputting frame data from and to a circuit; buffer means for inputting and outputting an ATM cell sync signal and ATM cell data from and to an ATM switch; and reassembly means connected between said circuit termination means and said buffer means; said reassembly means for detecting a frame of an abnormal length from the ATM cell sync signal and the ATM cell data from said buffer means, compensating, when a frame of an abnormal length is detected, for the abnormal length of the frame with data from a next frame, and outputting a resulting frame as a frame pulse signal and frame data to said circuit termination means.