It is in length and uses Wavelength Division Multiplexing ( " WDM " ) technology with Synchronous Digital Hierarchy ( " SDH " ) transmission to increase capacity and enhance the quality of the signal, especially over long distances ( this cable stretches from North Germany to Australia and Japan ).
32.
Synchronous Optical Networking ( SONET, in the U . S . and Canada ) and Synchronous Digital Hierarchy ( SDH, in the rest of the world ) are the standard multiplexing protocols used to carry high-data-rate digital bit-streams over optical fiber using lasers or highly coherent light from light-emitting diodes ( LEDs ).
33.
The infrastructure components which Telekom will instal include both copper and fibre optic cables to support high bandwidth multimedia communications and synchronous digital hierarchy ( SDH ) transmission; systems equipment; public switch telephone network ( PSTN ) and integrated service digital network ( ISDN ) switches; a trunk network system; asynchronous transfer mode ( ATM ) core; and access switches and a customer access network.
34.
At the time of the design of ATM, 155 Mbit / s Synchronous Digital Hierarchy ( SDH ) with 135 Mbit / s payload was considered a fast optical network link, and many plesiochronous digital hierarchy ( PDH ) links in the digital network were considerably slower, ranging from 1.544 to 45 Mbit / s in the USA, and 2 to 34 Mbit / s in Europe.
