2_3 and 2_4 ofc and ofs
TRANSCRIPT
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
1/69
BHARAT SANCHAR NIGAM LIMITED
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
2/69
BHARAT SANCHAR NIGAM LIMITED
Introduction of OFC.
OF Cable is a guided medium, in which
information (voice, data or video) is
transmitted through a glass or plastic fibre, in
the form of light from one end to other end.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
3/69
BHARAT SANCHAR NIGAM LIMITED
Technology in OF cable.
Transmission sequence Principles of operation
TIR
Propagation of light
To Achieve TIR
Value of IOR
Propagation angle
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
4/69
BHARAT SANCHAR NIGAM LIMITED
Optical parameters.
Wavelength
Frequency
Window
Attenuation
Dispersion
Bandwidth or NA
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
5/69
BHARAT SANCHAR NIGAM LIMITED
Type of OF Cable.
Single Mode Fibre
Multi Mode Fibre
Plastic Optic Fibre
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
6/69
BHARAT SANCHAR NIGAM LIMITED
Single Mode Fibre
A much smaller core Diameter
The Core dia is 8 to 10 Micrometer
Cladding Dia is 125 Micrometer
Very large bandwidth
Light can go for very long distances
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
7/69 BHARAT SANCHAR NIGAM LIMITED
Multimode
Has a large Core Diameter
Core Diameter - 50, 62.5, 100 Micro meterCladding dia - 125 Micro meter
Light waves are dispersed into number ofpaths
Multiple path of light cause signal distortion
Suitable for shorter length like LAN
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
8/69 BHARAT SANCHAR NIGAM LIMITED
Graded Index Fibre
Multi Mode Fibre
Step Index Fibre
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
9/69 BHARAT SANCHAR NIGAM LIMITED
Advantages of OF Cable.
Unlimited bandwidth
Low Loss - 0.5db per km
Less number of Repeaters
Electro Magnetic Immunity
Small size & Light Weight - Easy to handle
Greater Safety - No Electric Hazards
Higher Security
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
10/69
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
11/69 BHARAT SANCHAR NIGAM LIMITED
Parameters of Cabling
Tensile Strength ( Pull)
Crushing Resistance
Protection from Excess Bending
Abrasion Protection
Anti-Twist
Chemical protection
OFC Construction
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
12/69 BHARAT SANCHAR NIGAM LIMITED
1. Core
It is made by silica or Glass
More RI and it is 1.48
diameter 8-10 micrometer
Light is transmitted through
the core
2. Cladding
It is made by silica or glass
More RI and it is 1.46
diameter 125 micrometer
OFC Construction
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
13/69 BHARAT SANCHAR NIGAM LIMITED
OFC Sizes
6 Fibre
12 Fibre
24 Fibre
48 Fibre
96 Fibre
Note: Standard drum length is 2000M
+10% 0r 4000 m
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
14/69 BHARAT SANCHAR NIGAM LIMITED
PDH
Plesiochronous Digital Hierarchy.
Support large amount of data to transport .
The term PLESIOCHRONOUS is derived from Greek plesio
which means near, and chronous, time.
It means, networks works in different state but not perfectly
within network.
Transmission and reception are synchronized but timing is not
The channel clocks derived from diff master clock and range is
within limit . It called PLESIOCHRONOUS SIGNAL.
PDH signal are neither SYNCHRONOUS nor ASYNCHRONOUS.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
15/69 BHARAT SANCHAR NIGAM LIMITED
VERSIONS OF PDH
There are two version in PDH namely
THE EUROPEAN AND
THE AMERICAN.
They are different Bit rates and same
EUROPEAN PCM = 30 CHANNELS
NORTH AMERICAN PCM = 24 CHANNELS
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
16/69 BHARAT SANCHAR NIGAM LIMITED
EUROPEAN PDH HIERARCHYWITH BIT RATES
MUX BIT RATE PARTS PERMILLION
CHANNELS
2 Mbps 2.048 Mbps +/- 50 ppm 30
8 Mbps 8.448 Mbps +/- 30 ppm 120
34 Mbps 34.368Mbps
+/- 20 ppm 480
140 Mbps 139.264Mbps
+/- 15 ppm 1920
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
17/69 BHARAT SANCHAR NIGAM LIMITED
MULTIPLEXING TECHNIQUE
Digital data from multiple streams are combined
called Multiplexing .
Taking one bit from each stream and followed byother one .
Multiplexer also adds some additional bits to
enable the reliable.
The additional bit called JUSTIFICATION OR
STUFFING bits.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
18/69 BHARAT SANCHAR NIGAM LIMITED
30 Chl Digital Hierarchy
III Order
Mux
480 Chls
IV Order
Mux
1920 Chls
Primary
Mux
30 ChlsII orderMux120 Chls
X 4 X 4
2.048 Mbps 8.448 Mbps 34.368 Mbps 139.264 Mbps
X 4
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
19/69 BHARAT SANCHAR NIGAM LIMITED
DIGITAL MUX CONCEPTS
BIT INTERLEAVING: It means Alternately each channel code can be
scanned one digit at a time.
It is adopted in Higher order Multiplexing.
BYTE/WORD/BLOCK INTERLEAVINGIf TS is long enough to accommodate thegroup of bits, then signal called Byteinterleaving.
A1 A2 A3 A4 B1 B2 B3 B4 C1 C2 C3 C4 D1 D2 D3 D4
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
20/69 BHARAT SANCHAR NIGAM LIMITED
SLIP, JUSTIFICATION AND JITTER
SLIP This occurs when incoming bit rates does
not match with the divided MUX/DEMUX clock
rate .Same bit may be read twice or loss of bit
will occur.
JUSTIFICATION:- It is process of adding
additional bits to solve this SLIP problem.
JITTER:- Displacement of pulse from its normal
significant instant is called Jitter.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
21/69 BHARAT SANCHAR NIGAM LIMITED
PROBLEMS INVOLVED IN HIGHER ORDERMULTIPLEXING AND SOLUTIONS FOR THEM
MUX CLOCK SPEEDS SHOULD BE SAME AT BOTH THEENDS.
SOLUTION :- It solved by using PLL circuit at receive tmlto recover the clock.
SYNCHRONIZATION:-SOLUTION- It is solved by FRAME ALIGNMENT WORD(FAW).
TRIBUTARY BIT RATE AND MUX CLOCK (DIVIDED)SHOULD BE THE SAME:-
SOLUTION - It is solved by adding additional Stuffing bitor Justification bit during process.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
22/69
BHARAT SANCHAR NIGAM LIMITED
FOTS
FIBRE OPTIC TRANSMISSION SYSTEM.
It has the following sub system
DIGITAL MULTIPLEX SUB SYSTEM.
OPTICAL LINE TRANSMISSION SUB SYSTEM.
CENTRAL SUPERVISORY SUB SYSTEM
POWER SUB SYSTEM
ALARM SUB SYSTEM
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
23/69
BHARAT SANCHAR NIGAM LIMITED
LIMITATIONS
Lower capacity
Add and drop difficult
MUX/DEMUX process Complex
No Universal standard
Internetworking betn. Hierarchies complex.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
24/69
BHARAT SANCHAR NIGAM LIMITED
DISADVANTAGES OF PDH SYSTE
Bandwidth is limited
To access LO tributary involves whole process.
No common standard between vendors.
Only Point to Point configuration.
No provision for NMS
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
25/69
BHARAT SANCHAR NIGAM LIMITED
SYNCHRONOUS :ONE MASTER CLOCK & ALL ELEMENTSSYNCHRONISE WITH IT.
DIGITAL:INFORMATION IN BINARY.
HIERARCHY:
SET OF BIT RATES IN A HIERARCHIAL ORDER.
WHAT IS S D H ?
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
26/69
BHARAT SANCHAR NIGAM LIMITED
ADVANTAGES OF SDH
1. SIMPLIFIED MULTIPLEXING/DEMULTIPLEXING TECHNIQUES.
2. DIRECT ACCESS TO LOWER ORDER TRIBUTARIES.
3. ACCOMMODATES EXISTING PDH SIGNALS.
4. CAPABLE OF TRANSPORTING BROADBAND SIGNALS.
5. MULTI-VENDOR, MULTI OPERATOR ENVIRONMENT.
6. PROTECTION SWITCHING TO TRAFFIC IS OFFERED BY RINGS.
7. ENHANCED BANDWIDTH.
8. NMS FACILITY.
9. UNLIMITED BANDWIDTH
10. GROWTH OF THE EXISTING TO THE HIGHER ORDER SYSTEM IS
SIMPLE.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
27/69
BHARAT SANCHAR NIGAM LIMITED
The Container (C)
Basic packaging unit for tributary signals (PDH)
Synchronous to the STM-1
Bitrate adaptation is done via a positive stuffingprocedure
Adaptation of synchronous tributaries by fixed
stuffing bits
Bit by bit stuffing
The Virtual Container (VC)
Formation of the Container by adding of a POH(Path Overhead)
Transport as a unit through the network (SDH)
A VC containing several VCs has also a pointerarea
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
28/69
BHARAT SANCHAR NIGAM LIMITED
The Tributary Unit (TU)
Is formed via adding a pointer to the VC
The Tributary Unit Group (TUG) Combines several TUs for a new VC
The Administrative Unit (AU)
Is shaped if a pointer is allocated to the
VC formed at last
The Syncronous Transport Module Level 1(STM-1)
Formed by adding a Section Overhead (SOH) toAUs
Clock justification through positive-zero-negativestuffing in the AU pointer area
byte by byte stuffing
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
29/69
BHARAT SANCHAR NIGAM LIMITED
STM1 Frames
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
30/69
BHARAT SANCHAR NIGAM LIMITED
STM-N AUG AU-4 VC-4
TUG-3 TU-3 VC-3
C-4
C-3
TUG-2
TU-1 VC-1 C-1
140Mbps
34Mbps
2Mbps
(REDUCED DIAGRAM FOR SDH-MULTIPLEXING)
REDUCED MUXSTRUCTURE
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
31/69
BHARAT SANCHAR NIGAM LIMITED
Containers: C-3, C-2, C-12 and C-11
Container Carries signals at
C-11 1.544 Mbit/s
C-12 2.048 Mbit/s
C-2 6.312 Mbit/s
C-3 34.368 Mbit/s and 44.736 Mbit/s
C-4 139.264 Mbit/s
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
32/69
BHARAT SANCHAR NIGAM LIMITED
SDH BIT RATES
SDH Levels Bit rates in Kbps
STM-1 155520
STM-4 622080
STM-16
STM-64
2488320
9953.28
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
33/69
BHARAT SANCHAR NIGAM LIMITED
SOH BYTE ALLOCATION
A1A2 Frame alignment
B1B2 Error monitoring
D1..D3 Data comm channel for RSOH
D4..D12 Data comm channel for MSOH
E1-E2 Order wire channel
F1 Maintenance
J0 STM Identifier
K1 K2 Automatic protection switching
S1 SYNCHRONISATION STATUS
M1 Txmn Error acknowledgement
Media dependent bytes
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
34/69
BHARAT SANCHAR NIGAM LIMITED
SDH NETWORK ELEMENTS
The different network elements are
SYNCHRONOUS MULTIPLEXER
SYNCHRONOUS DIGITAL CROSS CONNECT
REGENERATOR
NMS
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
35/69
BHARAT SANCHAR NIGAM LIMITED
SYNCHRONOUS MUX
Types of synchronous multiplexers
TERMINAL MULTIPLEXER(TM)
ADD DROP MULTIPLEXER(ADM)
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
36/69
BHARAT SANCHAR NIGAM LIMITED
TM
TERMINAL MULTIPLEXER(TM)
TM Accepts a no. Of tributary signals and
multiplex them to appropriate optical/electrical
aggregate signal viz STM1,STM4,STM16 etc.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
37/69
BHARAT SANCHAR NIGAM LIMITED
TERMINAL MULTIPLEXER(TM)
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
38/69
BHARAT SANCHAR NIGAM LIMITED
Only signals that need to be accessed are
dropped or inserted
Remaining traffic continues thru the NE
without requiring special signal process.
ADD DROP MULTIPLEXER(TM)
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
39/69
BHARAT SANCHAR NIGAM LIMITED
ADM
ADD DROP MULTIPLEXER(TM)
AGGREGATE SIGNAL AGGREGATE SIGNALSDH(E/O) SDH(E/O)
ADM
TRIBUTARY SIGNALS (PDH/SDH)
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
40/69
BHARAT SANCHAR NIGAM LIMITED
ADD DROP MULTIPLEXER(ADM)
ADD DROP MULTIPLEXER(ADM)
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
41/69
BHARAT SANCHAR NIGAM LIMITED
It works as semi permanent switch for varying
B/W.
It can pick out one or more lower order channelsfor transmitting signal without trans. Chls.
Chls. can be 64Kbps up to STM1
Under software program the need of
demultiplexing
CROSS CONNECT EQUIPMENT
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
42/69
BHARAT SANCHAR NIGAM LIMITED
TYPES OF NETWORKTOPOLOGY
STRING/BUS/LINEAR Topology
RING Topology
STAR Topology
MESH Topology
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
43/69
BHARAT SANCHAR NIGAM LIMITED
STRING/BUS/LINEARTOPOLOGY
TMADM ADM ADMREG
Aggregate signal
Tributarysignal
(STM1/STM4/STM16)
(2/34/140Mbps/STM1(e)/ STM1(o))
TM
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
44/69
BHARAT SANCHAR NIGAM LIMITED
RING TOPOLOGY
Ring is a linear network looped back to
itself
Network elements are ADMs or
REGENERATORS
Every node on a ring has two
communication paths to each other node
via the two directions around the ring.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
45/69
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
46/69
BHARAT SANCHAR NIGAM LIMITED
RING TOPOLOGY
Ring network is self healing type
Ring protocol can detect failure of fibre
segment or node
Then rapidly reestablish communications,
Duration is on the order of milliseconds.
It known as protection or protection
switching
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
47/69
BHARAT SANCHAR NIGAM LIMITED
RING TOPOLOGY
Rings gives greater flexibility in the
allocation of band width to thedifferent users.
Normally used in LAN,WAN, Core
Network,Regional Network etc.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
48/69
BHARAT SANCHAR NIGAM LIMITED
STAR TOPOLOGY
Traffic passes thru a central node called
HUB.
The HUB is a DXC.
If HUB fails ,total traffic fails.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
49/69
BHARAT SANCHAR NIGAM LIMITED
DWDM BASICS
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
50/69
BHARAT SANCHAR NIGAM LIMITED
DWDM BASICS
SINGLE FIBRE
SDH OPTICAL SIGNALS
NEW REQUIREMENTS:
A hi i hi h b d idth
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
51/69
BHARAT SANCHAR NIGAM LIMITED
Achieving high bandwidth
Three possible solutions.
Install new fiber
Invest in new TDM
technology to achieve
higher bandwidth.
Deploy DWDM
Expensive
Very expensiveRequire new typefibre.
Economical.
DWDM
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
52/69
BHARAT SANCHAR NIGAM LIMITED
DWDM
DWDM IS A TECHNOLOGY THAT USES MULTIPLE LASERS
TO TRANSMIT MANY WAVELENGTHS OF LIGHTSIMULTANEOUSLY OVER A SINGLE OPTICAL FIBRE.
EACH SIGNAL IS MODULATED BY DIFFERENT SOURCE
DATA (TEXT, VIDEO ETC) AND TRAVELS WITHIN ITS OWN
UNIQUE COLOUR BAND WAVELENGTH.
DWDM DRAMATICALLY INCREASES THE FIBRE
INFRASTRUCTURE IN THE OPTICAL TRANSPORT NETWORK.
BIT RATE TRANSPARENCY
QUICK DEPLOYMENT
WAVELENGTH ROUTING
WAVELENGTH SWITCHING.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
53/69
COMPONENTS AND OPERATION
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
54/69
BHARAT SANCHAR NIGAM LIMITED
COMPONENTS AND OPERATION
TRANS SIDE:- LASERS WITH PRECISE AND STABLE WAVE
LENGTH.
LINK SIDE:- FIBRE THAT EXHIBITS LOW LOSS AND
TRANSMISSION PERFORMANCE IN THE RELEVANT
WAVELENGTH SPECTRA, IN ADDITION TO FLAT GAIN
AMPLIFIERS TO BOOST THE SIGNALS ON LONGER SPAN.
RECEIVE SIDE:- PHOTO DETECTORS AND OPTICAL
DEMUX USING THIN FILM FILTERS OR DIFFRACTIVEELEMENTS.
OPTICAL ADM.
OPTICAL CROSS CONNECT COMPONENTS.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
55/69
BHARAT SANCHAR NIGAM LIMITED
DWDM SYSTEM Vs OTHER SYSTEMS
OTHER SYSTEMS
REGENERATORS WEREEMPLOYED TO BOOST ORREGENERATE THESIGNALS.
INDIVIDUAL SYSTEMS,INDIVIDUAL FIBRES.
CONSUMES MOREENERGY.
CAPACITY ENHANCEMENTWAS NOT POSSIBLE..
DWDM SYSTEMS
OPTICAL FIBREAMPLIFIERS ARE USEDCOMMONLY.
ONE COMMON FIBRE ISENOUGH.
OPTICAL COMPONENTSMINIMIZE ENERGY.
POSSIBLE TO ENHANCE
BANDWIDTH.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
56/69
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
57/69
BHARAT SANCHAR NIGAM LIMITED
MAIN NETWORK ELEMENTS
1.TRANSPONDER
2.OPTICAL MULTIPLEXER
3.OPTICAL DEMULTIPLEXER
4.OPTICAL AMPLIFIERS
5.OPTICAL ADD DROP MULTIPLEXER
6.OPTICAL CROSS CONNECT
7.OPTICAL REPEATER
JUST LIKE WIDENING OF ROAD USING AVAILABLE LAND TO MEET
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
58/69
BHARAT SANCHAR NIGAM LIMITED
JUST LIKE WIDENING OF ROAD USING AVAILABLE LAND TO MEET
INCREASED TRAFFIC.
STM 1
STM 4
STM 16
ATM
IP TFC
OFA
WDMWDM
TRANSPONDERS
TX RX
NEW REQUIREMENT OPTICAL SIGNALS
DWDM BLOCK SCHEMATIC
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
59/69
BHARAT SANCHAR NIGAM LIMITED
EXTRACTING HIGHER CAPACITY BY SENDING
SEVERAL LOW BITRATE SIGNALS ON SAME FIBRE
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
60/69
STAGES IN EVOLUTION OF
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
61/69
BHARAT SANCHAR NIGAM LIMITED
STAGES IN EVOLUTION OFOPTICAL COMMUNICATION:
Improvised Fiber
Point-to-point transport of medium bit ratesignals over short distance : single opticalchannel, 850 nm; using multimode (MM) fibre
Point-to-point transport of medium/high bitratesignals over medium/long distance : singleoptical channel 1310 nm; (Single Mode fibre)
Point-to-point transport of very high bitratesignals over long distance using two optical
channels (second & third windows) : WDM ; (SMfibre)
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
62/69
BHARAT SANCHAR NIGAM LIMITED
STAGES IN EVOLUTION OFOPTICAL COMMUNICATION:
EDFAs Invention of the Optical Amplifier (EDFA):
It amplifies all the DWDM channels in the fibre
The erbium doped fiber amplifier is the most
successful design for 1550 nm. (both L and C
bands)..
STAGES IN EVOLUTION OF
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
63/69
BHARAT SANCHAR NIGAM LIMITED
STAGES IN EVOLUTION OFOPTICAL COMMUNICATION:
NEW FIBRES Type of fiber:
DSF. G.653: Shifts dispersion minimum
from 1300 to 1550. Ideal for low loss, lowdispersion use with EDFAs.
DSF , G.654 (
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
64/69
BHARAT SANCHAR NIGAM LIMITED
STAGES IN EVOLUTION OFOPTICAL COMMUNICATION:
ACCESS Entry of Fibre into the access network (FTTC,
FTTB, FTTH) :
In order to meet the QoS, and bandwidth
requirements of customers. Also to overcome the limitations of existing
copper based access network.
This is facilitating the convergence of Long
distance with Local and Broadband serivces.
ADVANTAGES OF DWDM
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
65/69
BHARAT SANCHAR NIGAM LIMITED
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
66/69
BHARAT SANCHAR NIGAM LIMITED
Why Optical (DWDM)Networking?
Fibre Exhaust : Unlimited bandwidth on a fibrepair
Bit Rate Transparency
Format/Protocol Transparency : IP, ATM etc.
Efficient use and rearrangement of embeddedoptical capacity as per demand.
Minimal Capital Expenditure : CapacityExpansions Demand
Simpler Operations : Embedded DCC --->Limited Nes --> Alarm Storm
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
67/69
BHARAT SANCHAR NIGAM LIMITED
OPTICAL BANDS
EXTENSIVE USE OF WAVELENGTHS
DIFFERENT VENDORS:INTEROPERABILITY ISSUES
NEED FOR STANDARD WAVELENGTH VALUES
ITU Classification of bands
Standard values : ITU Grid
Center frequency: 193.10THz (1552.52 nm)
Standard spacings of 200, 100, 50 GHz for different
applications
ITU-T BAND ALLOCATION
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
68/69
BHARAT SANCHAR NIGAM LIMITED
ITU T BAND ALLOCATION
Optical
Supervisorychannel
1500 1520 1530 1542 1547 1560 1620
RED
BAND
C BAND L BAND
BLUE
BAND
C BAND PRODUCTS ARE COMMERCIALLY AVAILABLE. ERBIUM DOPED FIBRE AMPLIFIERS SUITABLE FOR C BAND.
GAIN IN RED BAND FLATTEST FOR EDFA. SOME MANUFACTURERS PROVIDE 16 CHANNELS IN
RED BAND ONLY. OTHERS USE BOTH RED & BLUE BANDS.
-
8/12/2019 2_3 and 2_4 Ofc and Ofs
69/69