Title :
Jitter testing technique and results at VC-4 desynchronizer output of SDH equipment
Author :
Bregni, Stefano ; D´Agrosa, Maria ; Valtriani, Luca
Author_Institution :
Network Technol. Div., SIRTI S.p.A., Milan, Italy
Abstract :
Many parameters have to be taken into account when testing an SDH (Synchronous Digital Hierarchy) apparatus. Specifications relative to jitter and wander generation, at the output of desynchronizer systems, represents one of the hottest topics in characterising SDH equipment. Among the many factors involved, pointer justifications, due to phase variations between the clock of the received timing signal and the internal clock of SDH equipment, play indeed a primary role in phase noise accumulation. This paper deals with the effects of AU pointer justifications, combined with the asynchronous mapping of plesiochronous tributaries in VC-4, in the phase rebuilding process of the demapped tributaries. Moreover, a detailed description of the testing technique is provided. Two different kinds of test have been designed for measuring and analysing phase transients from O Hz on, namely dynamic jitter measurement configuration and static jitter measurement configuration. Some results, obtained by applying this technique on different suppliers piece of equipment, are presented and their relative impact on normative is highlighted
Keywords :
digital communication; fault diagnosis; jitter; synchronous digital hierarchy; telecommunication equipment; telecommunication equipment testing; AU pointer justifications; SDH equipment; Synchronous Digital Hierarchy; VC-4 desynchronizer; asynchronous mapping; demapped tributaries; desynchronizer; dynamic jitter measurement; internal clock; jitter testing; phase noise accumulation; phase rebuilding; phase variations; plesiochronous tributaries; pointer justifications; static jitter measurement; timing signal; Character generation; Clocks; Gold; Jitter; Phase measurement; Phase noise; Synchronous digital hierarchy; Testing; Timing; Transient analysis;
Conference_Titel :
Instrumentation and Measurement Technology Conference, 1994. IMTC/94. Conference Proceedings. 10th Anniversary. Advanced Technologies in I & M., 1994 IEEE
Conference_Location :
Hamamatsu
Print_ISBN :
0-7803-1880-3
DOI :
10.1109/IMTC.1994.352159