What Does Synchronous Digital Hierarchy (SDH) Mean?
Synchronous digital hierarchy (SDH) is an international technology standard that utilizes light-emitting diodes (LED) or lasers for synchronous optical fiber communication.
Techopedia Explains Synchronous Digital Hierarchy (SDH)
During the early 1990s, SDH and synchronous optical networking (SONET) ignited an optical fiber industry movement. SDH/SONET were engineered for widely sourced circuit-mode communication transport–for example, digital signal 1 (DS1)—and encoded voice support via pulse-code modulation (PCM).
