View source for Plesiochronous Digital Hierarchy (PDH)

The plesiochronous digital hierarchy (PDH) is a telecommunications [[network]] transmission technology designed for the transport of large [[data]] volumes across large scale digital networks. The PDH [[design]] allows the streaming of data without having isochronous (clocks running at identical times, perfectly synchronized) to synchronize the signal exchanges. PDH clocks are running very close, but not exactly in time with one another so that when multiplexing, signal arrival times may differ as the transmission rates are directly linked to the clock rate. PDH allows each stream of a multiplexed signal to be bit stuffed to compensate for the timing differences so that the original data stream could be reconstituted exactly as it was sent.<ref>What is Plesiochronous Digital Hierarchy (PDH)? [http://www.sopto.com/st/multiplexer-knowledge/what-does-plesiochronous-digital-hierarchy-(pdh)-mean Sopto]</ref>