POINTER CONVERSION METHOD FOR SYNCHRONOUS DIGITAL HIERARCHY

Synchronous digital hierarchy (SDH) standardized in International Tele communication Union-Telecommunication Standard Sector (ITU-T) applies a new multiplexing method using a pointer that indicates a tributary l ocation in the SDH frame. The location of the SDH frame heads received from several lines is adjusted at interface circuits to facilitate th e multiplexing process in the;SDH equipment. Since the frame head loca tions of input signal differ from the output signal, pointer values ar e attached to the output signals. The pointer conversion of each tribu tary is performed independently of each other. Therefore the pointer v alues of tributaries transported on the same line might be different f rom each other after the conversion even if these values are the same. Hence large amounts of buffer memory would be required at the destina tion point to provide a transport service utilizing multiple virtual c ontainers (VCs). This paper proposes a new pointer conversion method t hat keeps the pointer value differences unchanged between tributaries multiplexed in an SDH frame. This method allows multiple VC transport service to be provided.