SDH stands for synchronous digital hierarchy. SDH is the synchronous technology used everywhere except the US, Canada and Japan. Development of this international counterpart to SONET began a few years after SONET. The differences between SONET and SDH are based primarily on the different asynchronous bit rates that must be mapped into them. In developing […]
Day: May 5, 2015
6 reasons why SONET
With the introduction of PCM technology in the 1960s, communications networks were gradually converted to digital technology during the years that followed. To cope with the demand for ever-higher bit rates, a multiplex hierarchy or plesiochronous digital hierarchy (DSn) evolved. The bit rates start with the basic multiplex rate of 1.5 Mb/s with a further […]
7 Reasons Why SDH (Synchronous Digital Hierarchy)?
Communications networks gradually converted to digital technology after PCM was introduced in the 1960s. A multiplex hierarchy known as plesiosynchronous digital hierarchy (PDH) evolved to cope with the demand for everhigher bit rates. The bit rates start with the basic multiplex rate of 2 Mbps with further stages of 8, 34, and 140 Mbps. In […]