Slide 1

Welcome to presentation on

Analysis of Synchronous Digital Hierarchy (SDH) Transmission Network in Teletalk

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Submitted by

Mesbah-ul Islam18th Batch, ID No: 082030201016Dept. of ETE , Prime UniversitySupervised byProfessor Dr. Abdul Mannan Sardar Dean, Faculty of Engineering Prime University, Mirpur-1, Dhaka-1216

Dhaka, Bangladesh July, 2011

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Transmission network consist of the following major transmission technologies:

Optical fiber communication link

Microwave communication link

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Transmission Network link

4Transmission Protocol

SDH (Synchronous Digital Hierarchy)

PDH ( Plesiochronus Digital Hierarchy)

Both optical fiber and microwave communication link support PDH and SDH link

Overview of Synchronous Digital Hierarchy (SDH) Transmission Network5

---- It stands for Synchronous Digital Hierarchy

---- It is a transmission protocol

---- It defines frame structure, multiplexing method, digital rates hierarchy and interface code pattern

---- It needs for a system to process increasing amounts of information

---- It is a new standard that allows mixing equipment from different suppliers

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Channel capacity of SDHSDHBit rateE1STM-1155.520 Mbps63STM-4622.08 Mbps252STM-162488.32 Mbps1088STM-649953.28Mbps4032

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Overview of PDH ( Plesiochronus Digital Hierarchy) Transmission Network8

---- It stands for Plesiochronus Digital Hierarchy

---- It is a transmission protocol

---- It is a technology used in networks run in a state where different parts of the network are nearly, but not quite perfectly, synchronized

----- It allows transmission of data streams that are nominally running at the same rate, but allowing some variation on the speed around a nominal rate9

SignalBit rateChannelE12.048 Mbps 30-31E28.448 Mbps 120-124E334.368 Mbps 480-496E4139.264 Mbps 1920-1984

Channel capacity of PDH10

Advantages of SDH over PDH PDH Electrical interfaces--- Only regional standards. PDH rate hierarchies for PDH: European (2.048 Mb/s), Japanese, North American (1.544 Mb/s). Optical interfaces--- No standards for optical line equipments, manufacturers develop at their will. SDHElectrical interfaces---Can be connected with existing PDH signals.

Optical interfaces---Can be connected to multiple vendors optical transmission equipments.

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Advantages of SDH (OAM function )PDH

Weak Operation, Administration & Maintenance function.12SDH

Abundant overheads bytes for operation, administration and maintenance

About 5% of the total bytes are being used

Advantages of SDH (Multiplexing methods) Low rate SDH to higher rate SDH ( STM-1STM-4STM-16STM-64 )

4:1STM-1ASTM-1BSTM-1CSTM-1D

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BDCBADCBASTM-4One Byte from STM-1 B13Figure 1:SDH Multiplexing

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14Disadvantages of PDH (Multiplexing)PDH : Asynchronous Multiplexing

The location of low-rate signals in high-rate signals is neither regular nor predictable

Not suitable for huge-volume transmission

140 Mb/s34 Mb/s34 Mb/s8 Mb/s8 Mb/s2 Mb/s

140 Mb/sde-multiplexerde-multiplexerde-multiplexermultiplexermultiplexermultiplexer

level by levelFigure 2: PDH Multiplexing

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Communication System OverviewMessageSourceTransmitterTransmissionMedium/ChannelReceiverMessageDestination

Noise,Interference,Distortion

Information Capacity, C = B log2 (1+SNR)Development trend: Increase the bandwidth

Move to higher frequencyFigure 3: Basic concept of transmission system

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Overview of SDH Microwave Communication16

Figure 4: P to P SDH MW link

SDH Optical Communication link Optical Communication: Deals with theory and applications of light wave signals (of frequencies ~1014 Hz or STM-256)

Optical Communication: Uses light as a medium of communicationOptoelectronics: Deals with other applications of light

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Overview of Optical CommunicationLight Source: LASER or LEDDigitalSignal

LightSource &ModulatorPhoto-detectorDigitalSignal

Optical FiberOptical Fiber: one or more glass fibers, and optoelectronic repeater or fiber amplifierDetector: APD or PINFigure 5: Optical communication

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Establishment of SDH Optical Transmission Network

19Figure 6:Establishment STM-16 SDH link

Ramna to Sher-e Bangla Nagar (SBN) SDH link

---- To be newly connection Ramna to SBN for GMSC, MSC,, BSC, MGW etc. HLR---- It is requirements STM-16 (2.5 Gbps) SDH link.

---- For STM-16 link the only physical media is suitable is Single mode optical fiber cable. Hence Single Mode G.652 fiber is selected between those sites and has been installed20

Justification of selected media SDH

---- Synchronous digital hierarchy (SDH) refer to a group of fiber- optic transmission rates that can transport digital signals with different capacities.

---- STM-16 SDH Multiplexer is cost-effective and compact STM-16 SDH multiplexer equipment designed to manage and derive services from the optical core to access

---- Microwave SDH link does not support STM-16 (2.5 Gbps).21

Link Loss BudgetTransmitterReceiver

ConnectorSpliceConnector

PowerDistance

Receiver Sensitivity

Link LossMarginFigure 7 : Optical loss budget

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Link MarginJust take the difference between transmitter power and receiver sensitivity

Example:

Tx =-20 dBRx = -30 dBLink Margin = 10 dB

The loss of the total cable system must not exceed the Link Margin

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Attenuation

Typical Attenuation for Single mode fiber:0.4 dB/km @ 1310 nm

Typical Attenuation for connector0.5 dB/connector @ 1310 nm

Typical Attenuation for Splice0.3 dB/Splice @ 1310 nm

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Cable Plant Passive Component Loss CalculationSM @1310 nm; typical values6 km length x 0.4 dB/km = 2.4 dB4 connector pairs x 0.5 dB = 2.0 dB4 splice (mechanical) x 0.3 dB = 1.2 dB___________________________________________________Total = 5.6 dBTransmitterReceiver

ConnectorSpliceConnector

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Cabinet Installation----Determining Cabinet Positions---- Marking Installation Hole Positions---- Installing Supports and Slide Rails---- Adjusting Support Height---- Fasten all bolts. Assembling Supports and Slide Rails--- Installing Floor Holder Fixing Components--- Installing Insulation Plates

Figure 8: Mux cabinet26

Optical Mux Installation----Optical mux installation inside the cabinet.---- Insert the optical interfaces (STM-16 S16.1 card) on the optics rack.---- Insert the Processing interface (PQ1 card)---- Insert the Tributary interface (D75S card)----- Optical Cross-connects (OXCs) processing board CXL16-----Digital Cross-connects (DXCs) board GXCSA

Figure 9: Optics 250027

Optical Distribution Frame (ODF) Installation--- Installing Insulation ODF rack----Verities type of optical connector. These are SC-FC , FC-FC, and LC-FC etc optical I-connector/Adapter---- Different types patch cord use in optical fiber for termination ODF to optical equipment----Optical patch cord connect between ODF and Optical interfaces board.

Figure 10:ODF

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Trunk Cable Installation---- The trunk cables include 75/120 E1 cables--- Electrical interface to connect optical interfaces.---- 63 E1 Digital distribution frame (DDF).---- Coaxial cable connect between DDF and Electrical interface.

Figure 11:DDF

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Power Cable Installation---- The labels are affixed to the DC cables that provide power for the cabinets---- the protection grounding cables, including the 48V, PGND, and BGND cables--- The labels for DC power cables are affixed to one side of the identification plates on cable ties

Figure 12:DC Power

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Optical fiber splicing---- Splicing is the act of joining two optical fibers end-to-end using heat---- Termination between two optical adapter--- Each Splice loss 0.5 dBm

Figure 13:Splice Machine

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Optical fiber loss measurement---- Optical fiber measurement equipment is Time Domain Reflecto meter (OTDR)---- Get actual optical fiber length 6.8 Km from OTDR 6.8 Km length x -0.4 dBm/km = -2.72 dBm 4 connector pairs x -0.5 dBm = -2.0 dBm 6 splice (mechanical) x -0.4 dBm = -2.4 dBm__________________________________________ Total = -7.12 dBm

Figure 14:OTDR

Figure 15:Optical power measure32

Interfaces optical power measurement---- Optical cross-connects (OXCs) CXL16 transmit power is -2 dBm---- Get optical power meter receive -2.1 dBm , wave length 1310nm ---- When fiber through interface from Ramna to SBN receive level is -12 dBm , wave length 1310 nm.---- Ramna and SBN almost same receive level.

Figure 16:Interface power measurement33

Ramna to SBN has been connected STM-16 link---- Ramna transmit power (TX) and SBN receive power (RX) is connected----Ramna receive (RX) and SBN transmit (TX) is connected

----Finally to be get Ramna receive level is -16 dBm and SBN receive level is -17 dBm---- Optical Mux threshold level is -26 dBm----STM-16 link has been completed.

Figure 17:STM-16 link34

Software Commissioning---- Starting the PC---- Setting IP Address for a PC ---- Starting the T2000-LCT Server---- Network Element Commissioning---- Configuring NE Commissioning Data ---- Configuration NE name, Date and Time---- Configuration Services to the NE for Commissioning

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Optical Commissioning---- Testing Fiber Connection---- Testing connection of Cables to interfaces ---- Testing Optical Fiber Jumper Connection ---- Testing Specifications of Optical Interfaces ---- Testing Received Optical power of an optical interface Board

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User Acceptance Test (UAT)

37Figure 18: UAT for Ramna to SBN

Visual Inspection of optical MUX Equipment ---- Management Function by LCT.---- Order wire Phone Test---- Power Supply Environment Test---- Optical Power Test---- Bit Error Rate Test---- ON/OFF Test.---- alarms (Critical, Major and Minor etc.).---- Check of BOQ.---- Visual checking of interconnection cables.---- Checking of Overall Installation.---- Checking of Physical Connection of Power.---- Continuity test of each & every E1 between the stations.---- Cable runs.---- DDF and DDF cabling.---- of Physical Connection of Earthling of the equipments 38

Conclusion---- STM-16 SDH link has been completed from Ramna to SBN---- Optical Cross connects (OXCs) and Digital cross-connects (DXCs) are to be completed---- Both site Ramna and SBN optical receive level are correct---- Optical receive level were some problem, when optical to be installed---- Get difference between optical fiber link budget loss and calculating optical measurement loss---- Finally STM-16 (2.5 Gbps) SDH link is ok.

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Thank you

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1A1

Indoor unit

Indoor unit

STM-1Optical Mux

STM-1Optical Mux