Synchronization in high-speed telecommunications networks

Synchronization is essential to the effective operation of telecommunications networks. Digital switching and transmission systems implemented in telecommunications networks today require synchronization to improve efficiency and prevent impairments. The essential role of synchronization in telecommunications networks is often misunderstood. Some of the methods typically used by the Bellcore Client Companies (BCCs) to maintain high quality, reliable synchronization in their networks are described in order to clarify the relevant concepts. These concepts can be useful in developing and maintaining efficient, high quality enterprise networks as well. Specifically, the synchronization hierarchy used in interoffice synchronization distribution is described. In addition, the Building Integrated Timing Supply (BITS) concept, a plan developed to meet intraoffice synchronization needs, is introduced. Synchronization requirements for both SONET and Asynchronous Transfer Mode (ATM) are discussed with special emphasis on the challenges these technologies pose for the current synchronization network and possible solutions. The Bellcore document Digital Network Synchronization Plan, GR-436-CORE, describes the BCC synchronization networks in greater detail