Data Transmission

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 […]