Formatumwandlungssystem für ATM-Zellen.

摘要

An ATM (Asynchronous Transfer Mode) cell format conversion system writes in a memory only a plurality of ATM cells each being 53 octets long and mapped in the payload fields of virtual containers VC-4-NC which have been multiplexed in the form of STM-N frames. A 1 octet long cell overhead is added to each of the ATM cells read out of the memory in response to base frame pulses which are synchronous to the STM-N frames, whereby the ATM cells are converted to 1-octet added ATM cells each being 54 octets long. The 1-octet added ATM cells and an idle cell are mapped in an imaginary 5 column groups x 9 rows matrix frame by frame and then outputted. This allows each of the STM-N frames to be switched to otherwise processed on an ATM cell basis.