NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation SYNCHRONOUS DIGITAL HIERARCHY Presented by Sanjib Kumar Nayak Roll # EC Under the Guidance of Mr. N. Srinivas

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation INTRODUCTION Started by Bellcore in 1985 as standardisation effort for the US telephone carriers (after AT&T was broken up in 1984), Later joined by CCITT (later: ITU), which formed SDH in 1987 Three major goals: – Avoid the problems of PDH – Achieve higher bit rates (Gbit/s) – Better means for Operation, Administration, and Maintenance (OA&M) SDH is THE standard in telecommunication networks now It is designed to transport voice rather than data It covers the lower 2-3 OSI layers SONET/SDH defines only a point-to-point connection in the network

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation WHY WE NEED SDH The Plesiochronous Digital Hierarchy had a number of problems: – Each multiplexing section has to add overhead bits for justification {higher rate -> more overhead) – Each part of the world has its own transmission hierarchy (expensive interconnection equipment) – Justification (bit stuffing) spreads data over the frame add-drop-multiplexers are hard to build extract a single voice call -> demultiplex all steps down switching of bundles of calls (n * 64 kbit/s) is difficult (every switch has to demultiplex down to DS0 level) – The management and monitoring functions were not sufficient in PDH – PDH did not define a standard format on the transmission link Every vendor used its own line coding, optical interfaces etc. Very hard to interoperate

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation SDH FEATURES AND MANAGEMENT Traffic Interfaces Management Functions Configuration management deals with the set of functions associated with managing orderly changes in a network. Performance management deals with monitoring and managing the various parameters that measure the performance of the network. Fault management is the function responsible for detecting failures when they happen isolating the failed component and restoring traffic that may be disrupted due to the failure.

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation SDH LAYERING SONET/SDH system consists of switches, multiplexers and repeaters(and the fiber in between) PATH is the connection between source and destination LINE runs between two multiplexers (possibly through repeaters) SECTION is the connection of any two devices (point-to point) PHOTONIC is the e/o and o/e conversion layer

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation NETWORK GENERIC APPLICATIONS Operations –Protection, for circuit recovery in milliseconds –Restoration, for circuit recovery in seconds or minutes –Provisioning, for the allocation of capacity to preferred routes –Consolidation or the funneling of traffic from unfilled bearers onto fewer bearers in order to reduce waste of traffic capacity –Grooming or the sorting of different traffic types from mixed payloads into separate destinations for each type of traffic. Equipment And Uses Optical- line systems Radio-relay systems Terminal multiplexers Add-drop multiplexers (ADM) Hub multiplexers

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation NETWORK TOPOLOGY Basic Fragments of Network Topology

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation SDH FRAME STRUCTURE

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation Multiplexing Structure

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation ELEMENTS OF SDH INFRASTRUTURE Terminal multiplexers Tributaries may be electrical or optical. Works as termination of path layer write POH {path overhead} Add-drop multiplexer Terminate connections in the line layer(write LOH-line overhead) Direct access to SDH frames in the bit stream. Example:drop and add STM-1 from/to STM-4 Every STM-1 can be mapped in and out separately without changing the remaining STM-N structures. Regenarator -Performs 3-R regeneration of the signals(amplify,reshape,reclock) Terminates connections in the section layers -writes SOH(section overhead) Regenerators performs opto/eletrical/optical conversions ADMs and DXCs have the same functionality of regenerators

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation CONCLUSION Almost all-new fiber-transmission systems now being installed in public networks use SDH or SONET Hence SDH has really revolutionized the transmission network by eliminating the physical limits of the transport medium (optical fiber) regarding higher line rates. The major telephone carriers in the world have deployed SDH networks. SDH deployed in three types of network configurations: point-to-point links, linear configurations, and rings.. SDH provides the combination of new services based on Ethernet with traditional services such as voice and guaranteed fixed circuits to corporate customers.

NATIONAL INSTITUTE OF SCIENCE & TECHNOLOGY Presented by: Sanjib Kumar Nayak Technical Seminar Presentation THANK YOU