What is the Difference Between SDH AND PDH ?

PDH and SDH are two different multiplexing techniques used in telecommunication. Theirmain features are shown below in brief;

PDH:Less synchronizedEasy to operateAbsent of high network management featuresLow data ratesHigh efficiency in allocating bits in the frameMore on manual control

SDH:Fully synchronizedMore software orientedNetwork management features availableHigh data ratesLow efficiency in the allocation of bits in the frameLow user interaction necessaryInteroperability is possible

advantages and disadvantages of SDH.

Advantages:Provision of high data ratesAvailability of advanced network management facilitiesLess user interactionInteroperability is possible

Disadvantages:High costComplex systemsHigh skill of staff required

PDH means ple synchronous Digital hierarchy. And SDH means synchronous Digital hierarchy

Around 1990, SDH was developed and launched to replace PDH systems and eliminate synchronization problems for bulk data and phone exchanges, as well as to increase data transfer rates and provide network simpler and more flexible based on fiber optics.

SDH has higher bitrate than PDH

E2 is not used in SDH

SDH is International standard for multiplexing

SDH has Protection Schemes but PDH has not.

SDH is a Synchronous Digital Hierarchy it is use for transfer data while PDH is Plesiochronous Digital Hierarchy help in proper transmission of data that generally runs at the similar rate but allows some slight variation in the speed than the nominal rate. 

maximum rate of PDH can transmit 140 MB/S

for SDH we can transmit 10GB/S

Pdh- used for less E1 and bandwith for lower speed and data rate,less synchronised.

Sdh- is high rate for transmission and high bandwitha and E1,totaly synchronised

SDH is a Standard technology for transmitting Data synchronously on Media while in PDH system, data streams are transmitted that are nominally running at same rate.

Though both Synchronous Digital Hierarchy (SDH) and Plesiochronous Digital Hierarchy (PDH) are related to transmission of large amounts of data for telecommunication systems, they accomplish this through different means. PDH transmits voice and large amounts of data using digital transport equipment, such as fiber optics and radio systems, according to Wikipedia. SDH transmits data synchronously using lasers on fiber optics or highly coherent light from LEDs.

1. PDH transmits voice and large amounts of data using digital transport equipment, such as fiber optics and radio systems. SDH transmits data synchronously using lasers on fiber optics or highly coherent light from LEDs

2. Another difference is that SDH can support higher data rates of transmissions than to PDH

PDH PARIALY SYNCHORNAIZED SDH TOTALY SYNC