40
CETTM MTNL 1 SDH & DWDM Systems SDH-DWDM MODULE ID: TGENSDS110
CETTM MTNL
1SDH & DWDM Systems
SDH-DWDM
MODULE ID: TGENSDS110
CETTM MTNL
2SDH & DWDM Systems
ContentsTransmission System What is PDH / SDH?SDH Bit Rates & HierarchyAdvantage of SDH SDH Network ElementsTypes of WDMWhat is DWDM?SDH/DWDM Topology Summary
CETTM MTNL
3SDH & DWDM Systems
Typical Transmission System
TelephoneExchange TelephoneExchange
Management System
DDF DDFMUX/DMUX
MUX/DMUX
E1 Links
E1 Links
MEDIA
MediaConverter
MediaConverter
CETTM MTNL
4SDH & DWDM Systems
Plesiochronous Signals
Plesiochronous : almost synchronous
A Plesiochronous system could arise as a result of two systems having slightly different clock readings over the time
In such a system one of the systems or a third system would need to notice the mismatch and make some compensating adjustment such as repeating or deleting a data packet or a frame.
CETTM MTNL
5SDH & DWDM Systems
Syn- with chronos-time
Synchronous signals are those that occur at the same clock rate when all clocks are based on a single ref clock
In a set of Synchronous signals, the digital transitions in the signals occur at exactly the same rate of all network elements
Synchronous signals
CETTM MTNL
6SDH & DWDM Systems
Limitation of PDH
Existing PDH is point to point system
O F capacity is under utilized
Difficulty in centralized supervision
Restoration of fault is time consuming
Manpower requirement is more
CETTM MTNL
7SDH & DWDM Systems
Synchronous: One master clock and all elements synchronized with it
Digital: Information in binary
Hierarchy: Set of bit rates in hierarchical order
SDH is an ITU-T standard for high capacity Telelecom network
SDH is a synchronous digital transport system, aim to provide a simple, economical and flexible telecom infrastructure
What is SDH?
CETTM MTNL
8SDH & DWDM Systems
SDH bit rates (G.707)
Apart from the above, There is STM-0 is of 51.84 Mb/s ( G.708 ).
STM-1 = 155 Mbit/sSTM-4 = 622 Mbit/sSTM-16 = 2.5Gbit/sSTM-64 = 10Gbit/s
One Section overhead
CETTM MTNL
9SDH & DWDM Systems
STM-1 frame structure
The STM n signal is multiples of frames consisting of 9 rows with 270 bytes in each row
The order of transmission : first from left to right and then from top to bottom
The first 9 bytes in each row are for information and used by the SDH system itself. This area is divided into 3 parts Regenerator Section Overhead(RSOH) Multiplex Section Overhead(MSOH) Pointers SOH bytes are used for communication between
adjacent SDH equipments.
CETTM MTNL
10SDH & DWDM Systems
PAY LOAD
RSOH
MSOH
AU Pointer
261 Columns
270 Columns
9 Columns
1-3 rows
5-9 rows
4th row
STM-1 frame structure
CETTM MTNL
11SDH & DWDM Systems
SDH Overhead
E2M1S1D12D11D10D9D8D7D6D5D4K2K1B2B2B2
AU pointerD3.D2..D1
XXF1.E1..B1XXJ0A2A2A2A1A1A1
RSOH
MSOH
The first 9rows x 9 columns
CETTM MTNL
12SDH & DWDM Systems
The basic STM frame is represented by a matrix of 9 rows and 270 columns.
Each column is one byte. Transmission is row by row starting from upper
left corner and ending at lower right corner The frame repetition is 125 micro seconds. One byte is 64Kbps. The frame comprises of section overhead,
pointer and pay load Number of bits per second =9 X 270 X 8 X8000
=155520000 or 155.52 Mbps
SDH Frame Structure
CETTM MTNL
13SDH & DWDM Systems
Container (C) The information from PDH signal is mapped into the
relevant container Each container then added with control information
known as Path Overhead Virtual Container (VC)
The container and the Path Overhead together form VC The path overhead bytes allow the network operator to
achieve end to end monitoring Tributary Unit (TU)
This is a information structure which provides adaptation between lower order path layer and the high order path layer
A TU Pointer is added to the VC.
SDH Multiplexing : Definitions
CETTM MTNL
14SDH & DWDM Systems
Tributary Unit Group (TUG) Contains one or more tributary units.
Administrative Unit (AU) The information structure which provides adaptation
between the higher order path layer and the multiplex section layer
Administrative Unit Group (AUG) Consists of AU3 or AU4.
Synchronous Transport Module (STM) Pay load information and over head information
organized in a block frame structure which repeats every 125 micro secs.
SDH Multiplexing : Definitions
CETTM MTNL
15SDH & DWDM Systems
Integrating PDH signals into STM-1
ContainerContainer
Virtual ContainerVirtual Container
Administrative UnitAdministrative Unit
Synchronous Transport ModuleSynchronous Transport Module
Path Overhead
Pointer
Section Overhead
Plesiochronous signal 140Mbit/s
C4
VC-4
AU-4
STM-1
CETTM MTNL
16SDH & DWDM Systems
SDH Multiplexing
C 3 VC 3 TU 3 TUG 3
X 3
34.368Mbps
(PDH)
C 12 VC 12 TU 12 TUG 2X 3
X 7
2.048Mbps(PDH)
MappingAligning
Multiplexing
Pointer Processing
VC 4 AU 4 AUG STM-NX N
139.264 Mbps(PDH)
C4
CETTM MTNL
17SDH & DWDM Systems
SDH Advantages
First world standard in digital format First optical InterfacesTransversal compatibility reduces networking
cost. Multivendor environment drives price down
Flexible synchronous multiplexing structure Easy and cost-efficient traffic add-and-drop
and cross connect capability
CETTM MTNL
18SDH & DWDM Systems
SDH Network Elements
Terminal multiplexer (TM)Add Drop Multiplexer(ADM)RegeneratorDigital cross connect (DXC)
CETTM MTNL
19SDH & DWDM Systems
SDH Network Elements Terminal multiplexer
The terminal multiplexer is used to multiplex local tributaries (low rate) to the STM-N (high rate) aggregate. The terminal is used in the chain topology as an end element
E1-E4E1-E4
STM-MSTM-M
STM-NSTM-NTM
CETTM MTNL
20SDH & DWDM Systems
SDH Network Elements Add Drop Multiplexer
The Add And Drop Multiplexer (ADM) passes the (high rate) stm-N through from his one side to the other and has the ability to drop or add any (low rate) tributary
The ADM used in all topologies
E1-E4E1-E4STM-MSTM-M
STM-NSTM-NADMADM
STM-NSTM-N
CETTM MTNL
21SDH & DWDM Systems
SDH Network Elements Regenerator
It mainly performs 3R function: 1R Re amplification 2R Retiming 3R Reshaping
It regenerates the clock and amplifies the incoming distorted and attenuated signal. It derive the clock signal from the incoming data stream.
STM-NSTM-NREGREG
STM-NSTM-N
CETTM MTNL
22SDH & DWDM Systems
SDH NE: Digital cross connect (DXC)
Ports
Ports
Ports
Ports
25
1
21
CETTM MTNL
23SDH & DWDM Systems
SDH- UTILISATION
STM-16/STM-4 Rings for core networks STM-1/STM-4 Rings for access network Mobile network backbone /backhaul Dual parenting of CNE/RSUs Broadband network Ethernet over SDH Packet over SDH
CETTM MTNL
24SDH & DWDM Systems
8e1 with /without ethernet ports16e1 21e132e142e1
STM1-CPE
CETTM MTNL
25SDH & DWDM Systems
CPE-features
1U/2U Chassis
Ac/dc Power option
Integrated multiservice option
Linear ring topologies
Multilevel protection schemes
CETTM MTNL
26SDH & DWDM Systems
CPE- Utilization
CNE/Low Capacity RSU
Dual parenting of CNE/RSU
Full capacity utilization in case of dual
parenting
Secured /dedicated rings for small/corporate
Customers
E-Line services
CETTM MTNL
27SDH & DWDM Systems
STM1-CPE UTILIZATION
CETTM MTNL
28SDH & DWDM Systems
Wavelength Division Multiplexing (WDM)
In telecommunications, Wavelength-Division
Multiplexing (WDM) is a technology which
multiplexes several optical carrier signals on
a single optical fiber by using different
wavelengths (colours) of laser light to carry
different signals
CETTM MTNL
29SDH & DWDM Systems
Types of WDM Systems
Coarse WDM (CWDM) Dense WDM (DWDM) Coarse WavelengthDivisionMultiplexing used in cable television networks and
intra-city telecom backbone networks (like MTNL Network),
Uses 8,16,32 wavelengths Cheaper and simple equipment
CETTM MTNL
30SDH & DWDM Systems
Wavelength Division Multiplexing (WDM)
DWDM ( Dense Wavelength Division Multiplexing ) can be thought of as a rope having a no. of threads twisted together; and each thread is analogous to one wavelength that can carry an optical communication system itself; could be a PDH ,SDH, etc Thus total capacity is the sum total of capacities of all the individual systems
CETTM MTNL
31SDH & DWDM Systems
ITU-T DWDM Grid
ITU-T G.694.1 (2002) ITU-T G.652.C for wavelengths ITU-T G.652.D for wavelengths Wavelength window around 1550 nm is used Some DWDM systems: - 0.8nm (100 GHz) channel spacing - 0.4nm (50 GHz ) channel spacing DWDM is an architecture that is transparent to - bit rate, Modulation format, protocols
CETTM MTNL
32SDH & DWDM Systems
OTU1OTU1OTU1OTU1
Input
Ch 1
Ch N
Ch 1
Ch N
11
n n OTUnOTUnOTUnOTUn
OM
UO
MU BABA LALA PAPA
OD
UO
DU
11
n n
OTU1OTU1OTU1OTU1
OTUnOTUnOTUnOTUnss ss ss ss
OSCOSC
OSCOSC OSCOSC
Output
EMS
Optical Transmitter OLA Optical Receiver
DWDM Architecture
CETTM MTNL
33SDH & DWDM Systems
DWDM System Components
Transponder (LASER + Modulator) Multiplexer Optical Fiber Optical Fiber Amplifier (OFA) Regenerator Demultiplexer Receiver (Detector + Demodulator)
CETTM MTNL
34SDH & DWDM Systems
DWDM Network Elements
1. DWDM Terminal multiplexer2. An intermediate optical terminal or Optical ADD-DROP multiplexer3. A DWDM terminal de-multiplexer 4. Optical Supervisory Channel (OSC)
CETTM MTNL
35SDH & DWDM Systems
Technology Advantages
Ability to offer new and higher-speed services in the Metropolitan Area at less cost.
Solve the problem of Fiber-Exhaust Transparency Scalability Dynamic provisioning Protected Services Data-centric Elimination of Regenerators
CETTM MTNL
36SDH & DWDM Systems
SDH / DWDM Network TopologyRING Topology
ADMNode AADM
Node A
ADMNode BADM
Node BADM
Node DADM
Node D
ADMNode CADM
Node C
STM1/4/16PDH/SDHTributariesPDH/SDHTributaries
PDH/SDHTributariesPDH/SDHTributaries
PDH/SDHTributariesPDH/SDHTributaries
PDH/SDHTributaries
PDH/SDHTributaries
CETTM MTNL
37SDH & DWDM Systems
SDH/DWDM Network TopologyPoint to Point
STM-NSTM-NTM TM
PDHPDH
STM-MSTM-M
PDHPDH
STM-MSTM-M
CETTM MTNL
38SDH & DWDM Systems
SDH / DWDM Network Topology
Point to Multipoint or Bus
STM-NSTM-NTM T
M
STM-NSTM-N
ADMADM
PDHPDH
STM-MSTM-M
PDHPDH
STM-M
STM-M
PDHPDH STM-MSTM-M
CETTM MTNL
39SDH & DWDM Systems
Application
High-traffic long haul routes Enterprise networks Metropolitan networks(city) Extending network to congested areas Inter-continental (submarine) routes
CETTM MTNL
40SDH & DWDM Systems
SummaryThe SDH Technology is proved to be a very
reliable transport technology DWDM Technology offer very high Bandwidth
and is still developing to offer all optical network of tomorrow
Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40
