Overview of the CCITT Recommendations for Synchronous Digital Hierarchy

This report contains an overview of the recent International consultative Committee for Telephone and Telegraph CCITT Recommendations for the Synchronous Digital Hierarchy SDH. The intention of this report is to give the reader, who has no prior knowledge of SDH, a simple insight into what SDH is and the associated terminology. This report does not provide an in depth analysis of SDH for this the reader is referred to the appropriate CCITT recommendations referenced in this report. The aims of SDH is to provide a more cost effective service for the conveyance of broadband communications than that offered with the present Plesiochronous Digital Hierarchy PDH system and the capability of integrating the current incompatible PDH systems employed in Japan, North America and Europe into a Single world-wide universal standard.