Design of TU-11/TU-12 level switching structure in optical transmission equipment which supports SDH (synchronous digital hierarchy) standard

In broadband communication, the design of the switching structure of the TU-11/TU-12 signals, the low level signals, is a necessary element for the ADM (add-drop multiplex) and DCS (digital cross-connection system) which compose the optical transmission equipment. This paper presents the multiplexing process of the low level signals that compose the STM-1 frame. In addition, it shows the design of the switching structure of the TU-11 and TU-12 signals used as the input signals of the transmission equipment, and suggests the method of designing the non-blocking switching structure which effectively reduces the existing memory area for the multi-port switching structure design. Actually, this memory saving switching structure has shown effective performance in the 4-port STM-1 frame, especially in the transmission equipment system over STM-4 (622.08 Mbps), and will be used widely in the system configuration that transmits data at 1 Gbps or faster.