ITU-T Kaleidoscope 2009
Innovations for Digital Inclusion
OPTICAL TRANSPORT
NETWORKS: FROM ALL-OPTICAL
TO DIGITAL
Virgilio Puglia
virgilio.puglia@tin.it
Olga Zadedyurina
olga.zadedyurina@disi.unitn.it
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
Outlines
Traditional DWDM based on OTN
(Optical Transport Network) ITU-T
G.872;
IPoDWDM;
ODN (Optical Digital Network);
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
ITU-T Kaleidoscope 2009 – Innovations for Digital Inclusion
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Introduction
IP traffic today becomes dominant:
New application based on IP (video
communication, P2P, etc.);
Old application migrate to IP (ex. SS7);
IP traffic has overcome capacity of
currently used wavelength 10Gb/s;
Today trend/evolution is:
Eliminate SDH/SONET layer;
Move Transport from Optical to Digital;
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
ITU-T Kaleidoscope 2009 – Innovations for Digital Inclusion
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Traditional DWDM as an OTN
DWDM is a fully optical network
which provides transparency:
only 1R regeneration (optical
amplification-equalization and CD
compensation);
theoretically the signal can be delivered
from every ONE to any other.
Traditional (OTN) approach becomes
hardly realizable for big network;
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
ITU-T Kaleidoscope 2009 – Innovations for Digital Inclusion
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IPoDWDM
IP routers
OTN
IP routers
IPoDWDM Approach
Insert IP traffic into DWDM without
mapping into SDH frame;
Integration of DWDM transponders
directly into IP switch/router.
Transponder
Transponder
G.709
Transponder
Transponder
G.709
Transponder
Transponder
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
ITU-T Kaleidoscope 2009 – Innovations for Digital Inclusion
Transponder
Colored interface
MUX
Gray interface
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IPoDWDM intelligence
Preemptive traffic protection becomes possible
IPoDWDM
LOF
FEC Limit
Work path
Optical Impaiments
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
ITU-T Kaleidoscope 2009 – Innovations for Digital Inclusion
Protection path
BER
Lost
Protection p.
data
Corrected bits
BER
Corrected bits
Transponder
SDH/DWDM Layer IP Layer
Working path
IP Layer + G.709 on router
POS on router
OTN
FEC Limit
Switch threshold
Optical Impaiments
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Optical Digital Network Approach
The philosophy of ODN is based on
O-E-O conversion whenever it is
possible.
OTN manipulate analogical
wavelengths;
ODN manipulate digital “bits”.
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
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Network Layers: OTN vs ODN
OTN
ATM
Ethernet
STM-N
IP
Optical Channel Payload Unit (OPU)
Optical Channel Data Unit (ODU)
Optical Channel Transport Unit (OTU)
Optical Multiplex
Section (OMS)
Optical Transmission
Section(OTS)
OTM0
(not colored,
no OSC)
Optical Transport
Module (OTM-n,
n>1)
STM-N
Optical Channel Data Unit (ODU)
Optical Channel Transport Unit (OTU)
Optical Digital Channel (ODCh)
Analog
Analog
Optical Channel (OCh)
OTM0
Physical
Section
(OPSO)
ATM Ethernet
Optical Channel Payload Unit (OPU)
Digital
Digital
IP
ODN
OTM0
Physical
Section
(OPSO)
Band Multiplex
Section (BMS)
Optical Transmission
Section (OTS)
OTM0
Optical Transport Module
(not colored, (OTM-n, n>1)
no OSC)
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
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ODN advantages
Each OADM site implements 3R
regeneration:
the signal is cleaned up from noise and
others distortion;
It becomes possible to implement
higher number of Channels -160
(C band, spacing 25 GHz);
The network lose transparency.
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
ITU-T Kaleidoscope 2009 – Innovations for Digital Inclusion
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ODADM Description
Optical pass-through
FEC
Digital W.
DSP
DSP
MBM
O-E
O-E
O-E
O-E
O-E
O-E
Matrix
Matrix
O-E
East Line
Optical Spliter
O-E
O-E
O-E
O-E
O-E
O-E
O-E
FEC
Digital W.
Optical Spliter
West Line
MBM
Electrical connection
Optical connection
To interface modules
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
ITU-T Kaleidoscope 2009 – Innovations for Digital Inclusion
To interface modules
Specific Interface Module
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RECONCILATION BETWEEN THE
APPROACHES
To integrate different approach the
existing OTN network must support
Alien Wavelets (ITU-T G.698.2)
IPoDWDM is easy to integrate into OTN;
IPoDWDM is easy to integrate into ODN
but not efficiently;
ODN can be integrate into OTN using
an optical band split filter.
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
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Example of ODN-OTN integration
The majority of deployed DWDM networks are
equipped with 100GHz lambda spacing while
transponders have stability for 50GHz
spacing.
192.5
192.3
192.1
192
192.2
192.4
192.6West
Line
100
Ghz
192.05
192.25 192.45 192.65
192.15 192.35 192.55 192.75
Odd frequencies
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
ITU-T Kaleidoscope 2009 – Innovations for Digital Inclusion
C-Band
ODADM
C-Band
ROADM
50Ghz-100Ghz Filter
100
Ghz
50Ghz-100Ghz
Filter
Even frequencies
East Line
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Capacity Evolution
10 Gb/s -> 40 Gb/s -> 100 Gb/s
- CD increases and PMD appears;
OTN and IPoDWDM:
- the limit of 160 channels (L+C band)
ODN:
- due to E-O-E no dispersion problems.
- granularity of PIC is inflexible parameter (today
either 10 or 40 Gb/s based)
New capacities are
being studied by
IEEE 802.3ba
G.698.2 should
standardize new
interfaces
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
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Conclusions
OTN, IPoDWDM, ODN approaches
analyzed;
IPoDWDM and ODN are seen as very
promissing;
Examples on integration of both
technologies;
Stimulus for further research and
standardization activities;
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
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Back up
The following slide are for back up
OTN Network Elements
Client (not terminated in OADM site)
Och (not terminated in OADM site)
OMS
OTS
OLT
OLA
OMS
OTS
OTS
OLA
OTS
OADM
OTS
OLA
OLT
OLT (Optical Line Terminal)
OADM/ROADM (Optical Add Drop Multiplexer)
also Reconfigurable
OLA (Optical Line Amplifier)
OXC (Optical Cross-Connect)
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
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IPoDWDM Network Elements
Client-OCh-OTU-ODU-OPU (yellow & green lambda)
IP Router Client-OCh-OTU-ODUOPU(red & blue lambda)
Client-OCh-OTU-ODU-OPU
(red & blue lambda)
OMS
OTS
OTS
OMS
OTS
OTS
OTS
G.698.2 “black-link”
Optical colored interface
DWDM MUX/DMUX
Optical fibre
Optical Line Amplifier
OPU - Optical Channel Payload Unit
ODU - Optical Channel Data Unit
OTU - Optical Channel Transport Unit
OCh - Optical Channel
OMS - Optical Multiplex Section
ONE - Optical Network Element
OTS - Optical Transmission Section
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
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Client
ODN Network Elements
OPU
ODU
OTU
OTU
ODCh
ODCh
BMS
BMS
OTS
OTS
OTS
DNE
OTS
DNE
Electrical connection
Optical connection
OLA (Optical Line Amplifier)
MBM (Multiplexing Band Module)
OTS
DNE
OPU - Optical Channel Payload Unit
ODU - Optical Channel Data Unit
OTU - Optical Channel Transport Unit
DNE - Digital Network Element
ODCh - Optical Channel
BMS - Band Multiplex Section
OTS - Optical Transmission Section
Mar del Plata, Argentina, 31 Aug – 1 Sep 2009
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