PDH, SDH, OTN & ASON for Telecom Transmission

Name: PDH, SDH, OTN & ASON for Telecom Transmission
Rating: 4.8 (84 reviews)

Understand PDH (Plesiochronous Digital Hierarchy), Synchronous Digital Hierarchy (SDH)& Optical Transport Networks (OTN)

Highest Rated

Created byDr. Moazzam Tiwana

Last updated 3/2026

English

What you'll learn

Multiplexing in Telecom Transmission Networks
Physical Transmission Medium
Plesiochronous Digital Hierarchy (PDH)
Optical Fiber Transmission Media
Synchronous Digital Hierarchy (SDH)
Wavelength Division Multiplexing (WDM)
Optical Transport Networks (OTN)

Course content

6 sections • 83 lectures • 3h 8m total length

What is Multiplexing in Telecom Transmission Networks?2:39
Frequency Division Multiplexing (FDM) and its Standard Hierarchy3:52
Digital Exchanges: Analogue to Digital Conversion3:18
Discover how analog voice becomes digital in exchanges through pulse code modulation, with Nyquist criteria applied to 8 kHz sampling of a 4 kHz signal to 64 kbps per channel.
E-1 and T1 standard for TIme Division Multiplexing in Digital exchanges2:49
Plesiochronous Digital Hierarchy (PDH)3:03

What is Telecom Transmission Medium?1:11
Physical Transmission Medium for PDH2:24
Microwave Communication Overview0:44
What is Optical Fiber Communication?1:09
Total Internal Reflection as basic Principle of Optical Communication2:31
Types Of Optical Fiber1:54
Identify the three optical fiber types—multi mode step index, multimode graded index, and single mode—by core diameter, refractive index profiles, and cladding relationships, and compare their transmission implications.
Multimode Step Index Fiber and Modal Dispersion4:12
Multimode Graded Index Fiber2:38
Single Mode Optical Fiber1:49
Attenuation And The Wavelength Windows Used For Optical Communication2:01

Disadvantages of PDH1:55
PDH relies on bit-by-bit multiplexing of four e-1 inputs to yield an 8 mbps output, complicating channel identification and demanding costly demultiplexing infrastructure up to 565 mbps.
Introduction to Synchronous Digital Hierarchy (SDH)1:22
Introduce SDH as an improvement over PDH, enabling add/drop of low-rate signals from a high-rate stream, using byte-by-byte multiplexing with overhead, backward compatible with PDH, and enabling automatic path switching.
SDH Bit Rates1:18
SDH Accommodates the Existing PDH Signals as its Input1:43
SDH accommodates existing PDH signals as input by multiplexing E1–E4 into STM-1. STM-1’s higher bit rate enables fitting PDH signals, such as E1s, E3s, or E4.
Basic SDH Operations & Overall Multiplexing Structure For PDH to SDH Conversion1:33
Synchronous Transport Module (STM)-1 Frame Format4:00
Understand STM-1 frame format, defined in ITU-T G.707, transmitted every 125 microseconds as a 9×270 byte matrix with a VC-4 payload, including the Asuu pointer and regenerator/multiplex section overhead.
E4 to STM-1 Conversion in SDH2:47
E3 to STM-1 Conversion in SDH2:09
Explain E3 to STM-1 conversion by rate justification, forming C3 and VC-3 with tissue pointers and path overhead, and multiplexing tributary unit group three to VC-4, like E4 to STM-1.
E1 to STM-1 Conversion1:54
Convert a 2.048 mbps E1 to STM-1 by applying justification to 2.304 mbps, forming the C12 container and VC12, then multiplex tributary unit groups into VC4 with pointers and overhead.
Network Elements of SDH: 1. Regenerator0:51
Network Elements of SDH: 2. Multiplexers: Terminal & Add-Drop Multiplexers2:39
Network Elements of SDH: 2. Digital Cross-Connect (DXC)1:51
SDH Network Topology Types: 1. Point to Point Network Topology2:20
Explore the point to point SDH network topology, with two terminal multiplexers and regenerators along optical fiber to boost signals, enabling demultiplexing of low-rate tributaries.
SDH Network Topology Types: 2. Point-to-Multipoint Network Topology1:25
Illustrate how point-to-multipoint topology uses two terminal multiplexers and add/drop multiplexers to drop and add low-rate E1 signals within a high-rate SDH stream.
SDH Network Topology Types: 3. Mesh Network Topology1:28
SDH Network Topology Types: 4. Ring Network Topology2:11
SDH Overheads Classification0:34
Understanding main sections of SDH Path3:34
Regenerator Section Overhead (RSOH) Information3:45
AU Pointer (Administrative Unit Pointer) Information1:21
Multiplex Section Overhead (MSOH) Information5:05
Automatic Protection Switching: Linear Protection Mechanism2:58
Unidirectional Ring Protection-Line Switching1:57
Unidirectional Ring Protection-Path Switching1:29
Demonstrate unidirectional ring protection with path switching, where traffic runs on both working and protection lines. Station A monitors both paths for fast, receiver-only switching during a cable cut.
Bidirectional Ring Protection-Line Switching2:00

Wavelength Division Multiplexing (WDM) Concept2:40
Advantages of WDM Technology1:15
Wavelength-division multiplexing technology increases data capacity on a single fiber by multiplexing multiple wavelengths, enabling 16 stm 16 channels at 2.5 gbps to reach 40 gbps.
CWDM Vs DWDM Systems3:29
Optical Supervisory channel (OSC)2:34
The optical supervisory channel enables centralized management of dwdm nodes by carrying a dedicated wavelength for monitoring performance, detecting faults, and reconfiguring networks from a central network management station.
Optical Add Drop Multiplexer (OADM)1:16
Explore how the optical add drop multiplexer enables adding or dropping specific wavelengths at intermediate sites in a multiplexed optical fiber, while other wavelengths pass through.

Why Transition from SDH to OTN?2:52
Transition from SDH to OTN enables statistical multiplexing and flexible bandwidth for bursty IP and Ethernet traffic, transparently transporting client signals and delivering data rates beyond 100 Gbps per wavelength.
What is an Optical Transport Network (OTN)?2:00
Migration to Packet Transport Networking1:37
Migration to packet transport networking moves IP and Ethernet traffic over OTN. OTN acts as a wrapper with header and error correction, transparently carrying protocols and managing WDM wavelengths.
Why not IP directly over WDM?2:02
OTN Network Interface & 3R Regeneration Function3:36
Client Signal Mapping into Optical Channel1:37
Optical Channel (OCh) Structure2:06
OTN Layered Architecture3:33
Initial OTN Data Rates1:48
OTN Multiplexing Structure2:54
What is Optical Transport Module (OTM)1:24
The optical transport module, or otn protocol stack, defines protocol at each layer, from client signals to channels multiplexed by wavelength division multiplexing on a fiber, with three types.
OTM-n.m(Full Function OTM) Signal3:47
OTM-nr.m (Reduced Function OTM) Signal2:25
OTM-0-m (Single Wavelength OTM) signal1:19
ODU0-Efficient Transport of 1GbE2:13
ODUflex-Flexible Optical Channel Data Unit1:33
Commonly Used ODU Containers1:49
OPU Overhead Bytes Explained3:10
Explore the OTN overhead bytes, including the OPU overhead, path and section monitoring, payload structure identifier, and justification control bytes for positive and negative rate adaptation.
ODU Overhead Bytes-Path Monitoring (PM)3:04
ODU Overhead Bytes-Tandem Connection Monitoring (TCM)4:53
Other ODU Overhead Bytes1:43
OTU overhead Bytes2:49

Evolution of Transmission Networks2:12
The Limitations: What is Still Missing?2:13
Introduction of Automatically Switched Optical Network (ASON)0:58
How a New Service is Configured (Before ASON)?2:46
Evolution Towards ASON-Introducing Distributed OCC1:04
ASON Logical Structure1:24
ASON Control Plane1:18
Architecture of ASON NE2:53
How ASON Nodes Exchange Control Messages?1:19
GMPLS Protocol Used in ASON Control Plane3:30
How GMPLS Controls SDH-OTN-DWDM Switching?2:36
What is Service Level Agreement (SLA) in ASON?1:17
Two Key Mechanisms of Network Survivability: Protection vs Restoration2:14
SLA Tiers Example: 1) Diamond SLA Service (Highest Reliability)4:39
SLA Tiers Example: 2) Silver SLA Service (Medium Reliability)1:47
SLA Tiers Example: 3) Copper SLA Service (Unprotected)0:40

Requirements

Basic understanding of telecom terminologies

Description

Welcome to the course "PDH, SDH, OTN & ASON for Telecom Transmission". Telecom Transmission is the backbone of modern global telecommunications. Multiplexing is used to send multiple signals over a common high capacity transmission media, such as copper, microwave link or optical fiber. Whether you're an engineer, network professional, or a student eager to master telecom transmission technologies, this comprehensive course is designed to take you from foundational concepts to advanced optical networking.

You’ll begin with the basic principles of multiplexing and the evolution of telecom exchanges, moving through fiber optics fundamentals, then mastering Synchronous Digital Hierarchy (SDH). Finally, you'll explore the world of Wavelength Division Multiplexing (WDM) and Optical Transport Networks (OTN), understanding how high-speed networks are built and maintained today.

Course Outline:

Section 1: Introduction

What is Multiplexing in Telecom Transmission Networks?
Frequency Division Multiplexing (FDM) and its Standard Hierarchy
Digital Exchanges: Analogue to Digital Conversion
E-1 and T1 standard for TIme Division Multiplexing in Digital exchanges
Plesiochronous Digital Hierarchy (PDH)

Section 2: The Physical Transmission Medium

What is Telecom Transmission Medium?
Microwave Communication Overview
What is Optical Fiber Communication?
Total Internal Reflection as basic Principle of Optical Communication
Types Of Optical Fiber
Multimode Step Index Fiber and Modal Dispersion
Multimode Graded Index Fiber
Single Mode Optical Fiber
Attenuation And The Wavelength Windows Used For Optical Communication

Section 3:Synchronous Digital Hierarchy (SDH)

Disadvantages of PDH
Introduction to Synchronous Digital Hierarchy (SDH)
SDH Bit Rates
SDH Accommodates the Existing PDH Signals as its Input
Basic SDH Operations & Overall Multiplexing Structure For PDH to SDH Conversion
Synchronous Transport Module (STM)-1 Frame Format
E4 to STM-1 Conversion in SDH
E3 to STM-1 Conversion in SDH
E1 to STM-1 Conversion
Network Elements of SDH:
- Regenerator
- Multiplexers: Terminal & Add-Drop Multiplexers
- Digital Cross-Connect (DXC)
SDH Network Topology Types:
- Point to Point Network Topology
- Point-to-Multipoint Network Topology
- Mesh Network Topology
- Ring Network Topology
SDH Overheads Classification
Understanding main sections of SDH Path
Regenerator Section Overhead (RSOH) Information
AU Pointer (Administrative Unit Pointer) Information
Multiplex Section Overhead (MSOH) Information
Automatic Protection Switching: Linear Protection Mechanism
Unidirectional Ring Protection-Line Switching
Unidirectional Ring Protection-Path Switching
Bidirectional Ring Protection-Line Switching

Section 4:Using SDH Technology with Wavelength Division Multiplexing (WDM)

Wavelength Division Multiplexing (WDM) Concept
Advantages of WDM Technology
CWDM Vs DWDM Systems
Optical Supervisory channel (OSC)
Optical Add Drop Multiplexer (OADM)

Section 5:Optical Transport Network (OTN)

Why Transition from SDH to OTN?
What is an Optical Transport Network (OTN)?
Migration to Packet Transport Networking
Why not IP directly over WDM?
OTN Network Interface & 3R Regeneration Function
Client Signal Mapping into Optical Channel
Optical Channel (OCh) Structure
OTN Layered Architecture
Initial OTN Data Rates
OTN Multiplexing Structure
What is Optical Transport Module (OTM)
Optical Transport Modules Types
- OTM-n.m(Full Function OTM) Signal
- OTM-nr.m (Reduced Function OTM) Signal
- OTM-0-m (Single Wavelength OTM) signal
ODU0-Efficient Transport of 1GbE
ODUflex-Flexible Optical Channel Data Unit
Commonly Used ODU Containers
OPU Overhead Bytes Explained
ODU Overhead Bytes-Path Monitoring (PM)
ODU Overhead Bytes-Tandem Connection Monitoring (TCM)
Other ODU Overhead Bytes
OTU overhead Bytes

Who this course is for:

Telecom engineers and field technicians wanting to learn Telecom Transmission
Networking professionals working with optical transmission
Students in electronics, communications, or networking
Anyone preparing for telecom job interviews or certifications

PDH, SDH, OTN & ASON for Telecom Transmission

What you'll learn

Explore related topics

Course content

Introduction5 lectures • 16min

The Physical Transmission Medium10 lectures • 21min

Synchronous Digital Hierarchy (SDH)25 lectures • 54min

Using SDH Technology with Wavelength Division Multiplexing (WDM)5 lectures • 11min

Optical Transport Network (OTN)22 lectures • 54min

Automatically Switched Optical Network (ASON)16 lectures • 33min

Requirements

Description

Who this course is for: