25th January 2006 at 15:39
#38339
patrick
Guest
Plesiochrone Digital Hierarchy.
Synchronus Digital Hierarchy.
PDH= No synchro.
signal goes from point A to point B
SDH= synchro, you can make a big network.
signal goes from point A to point B, C , D , …
The trame is standardized. STM1, STM4, … like TDMA, CDMA, …