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Sdh vs pdh

Sdh vs pdh. Technologies used in telecommunication networks. introduction. PDH :- PLESIOCHRONOUS DIGITAL HIERARCHY. A TECHNOLOGY USED IN TELECOMMUNICATIONS NETWORK TO TRANSPORT LARGE QUANTITY OF DATA OVER DIGITAL TRANSPORT EQUIPMENT SUCH AS FIBRE OPTIC AND MICROWAVE RADIO WAVE SYSTEMS.

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Sdh vs pdh

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  1. Sdhvspdh Technologies used in telecommunication networks

  2. introduction • PDH :-PLESIOCHRONOUS DIGITAL HIERARCHY. • A TECHNOLOGY USED IN TELECOMMUNICATIONS NETWORK TO TRANSPORT LARGE QUANTITY OF DATA OVER DIGITAL TRANSPORT EQUIPMENT SUCH AS FIBRE OPTIC AND MICROWAVE RADIO WAVE SYSTEMS.

  3. Continue.. • THE TERM “PLESIOCHRONOUS” IS DERIVED FROM Greek plesio which means near, and chronous, time. • IT MEANS THAT PDH NETWORKS RUN IN A STATE WHERE DIFFERENT PARTS OF THE NETWORK ARE ALMOST, BUT NOT QUITE PERFECTLY SYNCHRONISED.

  4. Features of pdh • SENDING A LARGE QUANTITY OF DATA ON FIBRE OPTIC TRANSMISSION SYSTEM. • TRANSMISSION AND RECEPTION ARE SYNCHRONIZED BUT TIMING IS NOT. • THE CHANNEL CLOCKS ARE DERIVED FROM DIFFERENT MASTER CLOCKS WHOSE RANGE IS SPECIFIED TO LIE WITHIN CERTAIN LIMITS. THE MULTIPLEXED SIGNAL IS CALLED A “PLESIOCHRONOUS” SIGNAL. • PDH SIGNALS ARE NEITHER SYNCHRONOUS NOR ASYNCHRONOUS.

  5. Versions of pdh • THERE ARE TWO VERSIONS OF PDH NAMELY • 1) THE EUROPEAN AND 2 ) THE AMERICAN. • THEY DIFER SLIGHTLY IN THE DETAIL OF THEIR WORKING BUT THE PRINCIPLES ARE THE SAME. • EUROPEAN PCM = 30 CHANNELS • NORTH AMERICAN PCM = 24 CHANNELS • JAPANESE PCM = 24 CHANNELS • IN INDIA WE FOLLOW THE EUROPEAN PCM OF 30 CHANNELS SYSTEM WORKING

  6. EUROPEAN PDH HIERARCHY WITH BIT RATES

  7. LIMITATIONS • LOWER CAPACITY. • ADD AND DROP DIFFICULT. • COMPLEX MULTIPLEXING AND DEMULTIPLEXING. • NO UNIVERSAL STANDARD • INTERWORKING BETWEEN HIERARCHIES COMPLEX

  8. DISADVANTAGES OF PDH SYSTEM • PDH IS NO LONGER EFFICIENT TO MEET THE DEMANDS PLACED ON IT. • BANDWIDTH LIMITATIONS – MAX CAPACITY IS 566 MBPS ONLY. • NO COMMON STANDARDS AMONG VENDORS • POINT TO POINT CONFIGURATION ( LINEAR WORKING ) ONLY IS POSSIBLE. • IT DOES NOT SUPPORT HUB

  9. EVOLUTION OF SDH • Because of the disadvantages in the pdh technology, sdh technology is developed which overcomes all the drawbacks of an pdh technology. • thus sdh is an advanced technology.

  10. What is sdh ? • SYNCHRONOUS : • ONE MASTER CLOCK & ALL ELEMENTS SYNCHRONISE WITH IT. • DIGITAL: • INFORMATION IN BINARY. • HIERARCHY: • SET OF BIT RATES IN A HIERARCHIAL ORDER.

  11. ADVANTAGES OF SDH • SIMPLIFIED MULTIPLEXING/DEMULTIPLEXING TECHNIQUES. • DIRECT ACCESS TO LOWER ORDER TRIBUTARIES. • ACCOMMODATES EXISTING PDH SIGNALS. • CAPABLE OF TRANSPORTING BROADBAND SIGNALS. • MULTI-VENDOR, MULTI OPERATOR ENVIRONMENT. • PROTECTION SWITCHING TO TRAFFIC IS OFFERED BY RINGS. • ENHANCED BANDWIDTH. • NMS FACILITY. • UNLIMITED BANDWIDTH • GROWTH OF THE EXISTING TO THE HIGHER ORDER SYSTEM IS SIMPLE.

  12. DIFFERENT SERVICES • LOW/HIGH SPEED DATA • VOICE • INTERCONNECTION OF LAN • COMPUTER LINKS • FEATURE SERVICES LIKE HDTV • BROAD BAND ISDN TRANSPORT

  13. SDH BIT RATES

  14. SDH NETWORK ELEMENTS • The different network elements are • TERMINAL MULTIPLEXER • ADD/DROP MULTIPLEXER • REGENERATOR • SYNCHRONOUS DIGITAL CROSS CONNECT

  15. ADD DROP MULTIPLEXER(ADM)

  16. RING TOPOLOGY ADM ADM ADM REG ADM (STM1/STM4/STM16) Aggregate signal Tributary signal (2/34/140Mbps/STM1(e)/ STM1(o))

  17. conclusion • Pdh is obsolete now a days and replaced by sdh technology • Sdh has many advantage over pdh technology • Sdh encompasses features like hdtv ,isdn services which pdh is incapable of • It also provides high speed data transfer

  18. Thank you

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