(PDH) A transmission system for voice communication using plesiochronous synchronisation.
PDH is the conventional multiplexing technology for network transmission systems. The transmitter adds dummy information bits to allow multiple channels to be bit interleaved. The receiver discards these bits once the signals have been demultiplexed.
PDH combines multiple 2 Mb/s (E1) channels in Europe and 1.544 Mb/s (DS1) channels in the US and Japan.
PDH is being replaced by SONET and other SDH (Synchronous Digital Hierarchy) schemes.
[plee-see-uh-sawr] /ˈpli si əˌsɔr/ noun 1. any marine reptile of the extinct genus Plesiosaurus, from the Jurassic and Cretaceous periods, having a small head, a long neck, four paddlelike limbs, and a short tail. /ˈpliːsɪəˌsɔː/ noun 1. any of various extinct marine reptiles of the order Sauropterygia, esp any of the suborder Plesiosauria, of Jurassic […]
n. 1825, from Modern Latin Pleisiosaurus (1821), coined by English paleontologist William Daniel Conybeare (1787-1857) from Greek plesios “near,” related to pelas, + -saurus.
plessimeter ples·sim·e·ter (plě-sĭm’ĭ-tər) n. Variant of pleximeter.
[ples-er] /ˈplɛs ər/ noun, Medicine/Medical. 1. . /ˈplɛsə/ noun 1. another name for plexor plessor ples·sor (plěs’ər) n. Variant of plexor.