Mapping wander in SONET/SDH adaptive threshold modulation pointer processors

There are three types of pointer processors in synchronous optical network (SONET) and synchronous digital hierarchy (SDH) networks: traditional fixed threshold, uniform and adaptive threshold modulation. Fixed threshold pointer processors produce gapped pointer sequences as a result of the periodic effects of the SONET/SDH overhead bytes. These gapped pointer sequences cause wander when SONET/SDH carries PDH payloads. Uniform pointer processors smooth the gapped pointer sequences caused by the STM-N, AU and TU overhead bytes. Adaptive threshold modulation pointer processors (ATM-PPs) can also exhibit gapped pointer effects. This paper compares the wander from a gapped ATM-PP and the wander from a proposed uniform ATM-PP. The results indicate that this novel technique reduces wander