Turning elastic metro optical networks into reality...ELASTIC TRANSPONDERS (TRx) Reconfigurable Set...
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www.regione.piemonte.it/pnews/index.htm sommario Pernice bianca e lepre variabile, caccia vietata Sulle montagne piemontesi non si potranno cac- ciare la pernice bianca e la le- pre variabile, in quanto si voglio- no tutelare due specie a rischio di estinzione. L’assessore alla Caccia, Giorgio Ferrero, dopo l’approvazione di un’apposita delibera da parte della Giunta regionale, ha rilevato: «Abbiamo voluto tutelare due spe- cie particolarmente vulnerabili. La pernice bianca è considerata a ri- schio di estinzione su tutto l’arco alpino, rischio aggravato dal mal- tempo di questa estate che ne ha reso ancora più critiche le condizio- ni di vita. Per la lepre variabile ad oggi in Piemonte non esistono cen- simenti affidabili. Abbiamo perciò scelto di rendere concreta l’attenzione all’ambiente e alla tute- la delle specie animali a rischio che ci compete e in cui fortemente cre- diamo. Sarà poi la nuova legge re- gionale sulla caccia, su cui contia- mo di avviare le consultazioni sul nuovo testo entro la fine di ottobre, a definire in modo organico le spe- cie cacciabili in Piemonte». Alla vigilia dell’apertura della caccia Ferrero ricorda anche l’assunzione di altri due provvedimenti: «La ri- chiesta ai presidenti degli ambiti di caccia di imporre ai cacciatori di indossare giubbotti o bretelle ad alta visibilità, a tutela della loro sa- lute e di quella delle persone che frequentano zone di caccia ed il divieto di utilizzo di richiami vivi, cioè di uccelli tenuti in gabbia che con il loro canto attirano altri uccel- li, portandoli a tiro dei cacciatori». Riunioni della Giunta regionale su eterologa, bilancio e revisori dei conti Asr Fecondazione eterologa, asse- stamento al bilancio, revisori dei conti delle aziende sanita- rie sono tra i principali argo- menti trattati lunedì 15 e marte- dì 16 settembre dalla Giunta regionale, nel corso di due riu- nioni coordinate dal presidente Sergio Chiamparino. Eterologa. Come proposto dall’assessore Antonio Saitta, è stato recepito l’accordo raggiunto giovedì 4 settembre scorso dalla Conferenza delle Regioni, in considerazione della straordinaria necessi- tà ed urgenza di assicurare che le tecniche di procreazione medical- mente assistita di tipo eterologo si svolgano garantendo la salute di tutti i soggetti coinvolti. I centri pubblici e privati che intendono svolgere tale attività dovranno inviare un’apposita comunicazione alla Regione. Viene invece rinviata ad un successivo provvedimento la quantificazione eco- nomica delle prestazioni di tipo eterologo, in analogia agli indirizzi nazio- nali in corso di definizione. Il Comitato tecnico-scientifico insediatosi ve- nerdì scorso - composto dai direttori sanitari e dai responsabili dei centri pubblici di effettuare l’eterologa (Sant’Anna, Maria Vittoria e Civile di Fossano), un biologo ed un genetista sotto il coordinamento del direttore generale dell’assessorato - darà indicazioni univoche e precise sull'at- tuazione dell’accordo. Bilancio. Il disegno di legge di assestamento al bilancio di previsione 2014 presentato dal vicepresidente Aldo Reschigna, che passa ora all'e- same del Consiglio, evidenzia, per la limitata ampiezza dei suoi conte- nuti, l’estrema rigidità del bilancio regionale. «Abbiamo scelto - puntua- lizza Reschigna - di ridurre di 23 milioni di euro la voce di entrata relati- va alla vendita e alienazione di proprietà immobiliari, in quanto l’importo precedentemente iscritto non risulta raggiungibile entro la fine dell’anno. L’assestamento prevede inoltre la copertura per 36,5 milioni di euro del disavanzo 2013, cifra che rappresenta solo un decimo del totale, che sarà coperto negli esercizi futuri. Per quanto riguarda la spesa, le iscri- zioni riguardano principalmente importi già noti, tra cui 6 milioni per il trasporto pubblico locale, 6 per le borse di studio universitarie, 4 per le politiche sociali, al fine di riportare le risorse 2014 al livello del 2013 in un momento di grave difficoltà, uno per la cultura. A questi si aggiungo- no 15 milioni di euro (di cui 5 di fondi statali) per incrementare il fondo per l’esercizio delle funzioni conferite alle Province (dalla manutenzione delle strade allo sgombero neve) e 4 milioni di euro, sempre alle Provin- ce, per il trasporto scolastico». Revisori dei conti Asr. Un disegno di legge presentato dall’assessore Antonio Saitta, che passa ora all’esame del Consiglio regionale, dando attuazione ad una norma del Patto nazionale per la salute prevede che i revisori dei conti di ognuna delle 19 aziende sanitarie diminuiscano da 5 a 3 e siano nominati uno dalla Regione, uno dal Ministero della Salute e uno dal Ministero dell’Economia. Agenzia settimanale d’informazione della Giunta Regionale n. 32 del 19 settembre 2014
Transcript of Turning elastic metro optical networks into reality...ELASTIC TRANSPONDERS (TRx) Reconfigurable Set...
1 © Nokia 2018
Turning elastic metro optical networks into reality
Séminaire Telecom ParisTech 2019
• Patricia Layec, team
• 11-01-2019
Public
2 © Nokia 2018
1. Introduction
2. Today’s elastic optical networks
3. Towards true elastic networks
4. What needs to be replaced
5. What needs to be added
6. Conclusions
Public
Agenda
3 © Nokia 2018 Public
Introduction
Market segments
Picture from description of work of H2020 METRO-HAUL project
Access ~50km
Metro network ~100-500km
Core network ~500-10000km
~10Gb/s ~10-100Gb/s ~100-400Gb/s
4 © Nokia 2018
• Metro segment is growing 2x faster than core segment
• Key drivers for this growth
Metro video traffic will increase by 720% by 2017
Metro cloud and DC traffic will increase by 440% by 2017
- DC traffic includes DC-to-end-user & DC-to-DC (i.e. DCI) traffic
- Growth rate of DCI is 100% per year since 2012
Public
Introduction
Traffic is growing fast
[Bell Labs Consulting, “Metro network traffic growth: an architecture impact study,” Dec. 2013]
[A. Chen (Alibaba), W3B4, OFC 2016]
0
20
40
60
80
100
120
Tra
ffic
(T
b/s
)
metro backbone
2012 2013 2014 2015 2016 2017
5.6x
3.2x
560% INCREASE IN TOTAL METRO TRAFFIC
METRO TRAFFIC GROWS ALMOST
2X FASTER
5 © Nokia 2018
• Service providers are deploying video caching and cloud computing platforms within metro networks
- Better performance
- Better user experience
more traffic terminated in metro and not going to the core networks
Public
Introduction
Traffic distribution is changing
[Bell Labs Consulting, “Metro network traffic growth: an architecture impact study,” Dec. 2013]
Total IP traffic
IP traffic terminates in
metro network
57%
2012
Total IP traffic
IP traffic terminates in metro network
75%
2017
6 © Nokia 2018
• Traffic patterns are becoming meshed and variable
3-fold heterogeneity:
- connection lengths (and impairments),
- bandwidth requests on demand (capacity market)
- Smaller duration of connections (from months to minutes)
• Reach << 1000km
- Less DSP constraints
• Metro networks are also influenced by over-the-top (vs. telco)
Public
Introduction
Mismatch between dynamics of new services and optical transport
Most innovative solutions should appear in the metro networks
Metro Core
Meshed & variable traffic
patterns
7 © Nokia 2018
• Traffic patterns are becoming meshed and variable
3-fold heterogeneity:
- connection lengths (and impairments),
- bandwidth requests on demand (capacity market)
- Smaller duration of connections (from months to minutes)
• Reach << 1000km
- Less DSP constraints
• Metro networks are also influenced by over-the-top (vs. telco)
Public
Introduction
Mismatch between dynamics of new services and optical transport
Metro Core
Meshed & variable traffic
patterns
Most innovative solutions should appear in the metro networks
Try and learn Continuously adjust Always zero margins
Working with just-enough performance
Design and optimize Set and forget (for 15years) Guaranteed (large) margins Seeking top performance (bit-rate/distance)
OTTs Telcos
8 © Nokia 2018
• Elastic optical networks introduced in 2008 [M. Jinno et al, Th3F6, ECOC’08]
Public
Today’s elastic optical networks
Finisar
From BPSK to 16QAM 40G, 100G, 200G
Cisco
Multirate linecard BPSK, QPSK, 16QAM
50G, 100G, 200G
But in 1 touch can be upgraded to 200G.
Nokia
QPSK, 16QAM 100G, 200G
Infinera
QPSK N x 100G
superchannel
Reconfigurable transponder but in set & forget configuration
9 © Nokia 2018
Universal transponder: 1 does it all !
• Single hardware: single development cost, fast price erosion
• Similar technology for all rates: jointly optimized link design, limited XPM degradation
good side effects on engineering margin and planning tools
• Limit spares: single hardware device whatever the selected data rate [A. Morea et al, Th10F5, ECOC’10]
• Tunable devices: support easily traffic increase and network upgrades [O. Rival et al, P5.12, ECOC’12]
no need to uninstall and replace low rate devices with higher ones
Confidential
Today’s elastic optical networks
Set & forget configuration
Sp
ares
TS
P R
1
TS
P R
2
TS
P R
2
TS
P R
m
TS
P
TS
P
TSP
100Gbps 200Gbps
400Gbps
10 © Nokia 2018
Most popular usage is trade-off between capacity and optical reach
Fine granularity of flexrate technologies
• Set partitioning [J. Renaudier et al, We1C5, ECOC’12]
• Time hybrid QAM [X. Zhou et al, IEEE Com Mag., 2013]
• Probabilistic shaping [F. Buchali, et al., arXiv:1509.08836, 2015]
• FEC with puncturing
Today’s elastic optical networks
700 km 6000 km
+25% +50%
Fixed modulation, fixed power Adapted modulation, optimized power
[D.J. Ives et al., PNC, 29 (3), 2015]
t
Polar. X
8QAM
QPSK 8QAM QPSK
QPSK 8 QAM
Polar. Y
QPSK
8QAM
X Y
11 © Nokia 2018
PDM-QPSK optical spectrum
• Current networks mostly use a 50GHz fixed-grid
• Elastic networks enable flexgrid thanks to:
- Flexible channel spacing
- Tunable symbol rate of the transponder
=> Irregular grid with variable bandwidth of channels
- Techno-economics show a 20% spectrum savings with uniform traffic [A. Morea et al., OFC’11, JWA62]
Public
Today’s elastic optical networks
Spectrum
savings
60Gb/s in 100G l
75Gb/s in 100G l
50Gb/s in 100G l
50GHz
50 ps/div
FPGA electrical output
[A. Dupas et al., OFC’15, M3A2] Commercial WSS and ROADM have now very narrow granularity
12 © Nokia 2018 Public
Towards true elastic networks
ELASTIC TRANSPONDERS (TRx)
Reconfigurable
Set & forget configuration [Y. Zhou, et al. “1.4 Tb Real-Time Alien Superchannel Transport Demonstration Over 410 km Installed Fiber Link Using Software Reconfigurable DP-16 QAM/QPSK,” in JLT 2015]
Measured switching time (field trial with commercial hardware)
QPSK 16QAM : 40 sec 16QAM QPSK : 20 sec
TSP
100Gbps 200Gbps
400Gbps
13 © Nokia 2018 Public
Towards true elastic networks
ELASTIC TRANSPONDERS (TRx)
Reconfigurable
Set & forget configuration
SELF-EVERYTHING ELASTIC OPTICAL NETWORKS
Fast reconfigurable
Automated
Easy to use & configure
TSP
100Gbps 200Gbps
400Gbps
14 © Nokia 2018
• Easy to use and configure
- To trigger intents rather than specific hardware configuration => Tell what you need, not how to do
- e.g. low latency, 200G bandwidth, secure end-to-end connection, …
• Boulder project at Open Networking Foundation (ONF) is the first that really started working on the specifications and design of intent-based
- Open-source projects are developing intent-based networking
Public
Towards true elastic networks
NFV / Applications
Intent-based mediation
SDN controller
Data plane
vQOT vRSA vBoD …
Open day light
15 © Nokia 2018 Public
Towards true elastic networks
Perfect future network
M. Weldon et al., “The Future X Network: A Bell Labs Perspective,” ISBN 978-1498759267, CRC Press, 2015.
16 © Nokia 2018
• Highly scalable, tunable network fabric including:
- Disaggregated SDN network – to decouple the HW and SW that different lifecycle
- Adaptive impairment-aware optimization – to leverage monitoring and machine learning to optimize and automate the network
- Elastic optical metro transport – to allow specific innovation into the metro segment (i.e. low cost, low energy) while today innovation is driven by the core segment (i.e. performance)
- Ultra-scalable routers
• Network OS that fully automates and exposes the tunable network fabric
Confidential
Towards true elastic networks
Perfect future network
17 © Nokia 2018
KEY BENEFITS
• Assumptions:
- 10x traffic increase in 5 years
- Perfect future network
• TCO savings:
- OPEX & CAPEX for Optical (15%)
- OPEX & CAPEX for IP (43%)
And…
- Automation & optimization (42%)
Confidential
Towards true elastic networks
M. Weldon et al., “The Future X Network: A Bell Labs Perspective,” ISBN 978-1498759267, CRC Press, 2015.
IP/Optical cost/Gb
10x traffic
-71%
SDN automation / optimization (42%)
High scalable IP (43%)
High rate WDM (15%)
18 © Nokia 2018
• Data plane is already in good way
- CDC-F ROADMs
- Flexible elastic transponder (data rate, spectrum, tunable laser, etc.)
Commercial products (planned to be) deployed on field
Hardware foundations are ready for perfect future network
• Optical management tools
- Technology-specific
- Backward-compatible to previous generation of hardware
- SDN should become a carrier-grade system with resilient and secure functionalities
• Manual intervention
- Cabling between router ports and photonic nodes
To reduce delays of service creation (from weeks to days)
• Network programmability and applications come from upper layers
- Already happening in our day-to-day life
- dynamic bandwidth consumption,
- network as a service
Public
What needs to be replaced
Bottom-up
Top-down
19 © Nokia 2018
• Hitless data rate change for bandwidth on demand on optical transport
• State-of-the-art:
- 2017: commercial Field Trial, 20-35s switching time [JLT 2017, Y. Zhou et al., Vol 35, n°3]
- 2016: 450 µs switching time between 10 different bit rates [OFC’2016, A. Dupas et al., Th3I.1]
• Experimental proof-of-concept on 100Gbps real-time transmitter:
- Zero loss of data during data rate reconfiguration
- Flex symbol rate transponder (10G, 20G, …, 100G)
- a novel hitless protocol that buffers and synchronizes commands with data flows after all framing processing => No additional latency on data flows and service hitless switching.
=> Max switching time ~12µs.
Public
What needs to be added
Hitless data rate change (speed)
A. Dupas et al., “Ultra-fast Hitless 100Gbit/s Real-Time Bandwidth Variable Transmitter with SDN optical control,” Proc. OFC, 2018
To
fib
er
link
SDN Controller
Local controller
OTUflex-like
from 10 to
100Gbps
Hitless
coding
Tunable High
speed
interfaces
Hitless flexrate transmitter
Synchronization at the bit level
10ns/div
FPGA Clock For 160 bits
Command from SDN controller
Switching
10ns/div
20 © Nokia 2018
• Why?
- When crossing optical nodes, filter cascade reduces the available bandwidth => less tolerant to detuning
• Key goal: A self-optimizing transponder leveraging monitoring at the receiver side (no need for calibration)
- To reduce filter penalties by several dBs (worst case)
- To reduce the large filter design margin provisioned
• We propose an algorithm to safely cancel Tx/Rx lasers and filters misalignments
- Tx and Rx lasers are never perfectly aligned (+/-1.5GHz), and are not aligned with the optical filter cascade either (+/- 3GHz)
- Exact misalignments cannot be predicted
- Closed-loop automated algorithm that correct the effect of Tx/Rx frequency fluctuations using analytical metric
- No need for extra equipment (e.g. OSA)
Public
What needs to be added
Monitoring & closed-loop systems: filter mitigation
[O. Bertran Pardo et al., OFC’15]
Tx frequency correction
Tx Rx Detuned filter cascade (WSS)
Control plane
[C. Delezoide et al., OFC’19]
21 © Nokia 2018
• Analytical metric [C. Delezoide et al., OFC’19]
- Step #1: Filter effects are mitigated by the equalizer, hence we need to compute the power spectral density (PSD) after the Analog-to-Digital Converters (ADCs)
- Step #2: Metric based on the center of mass :
where Fs is the ADC sampling frequency and f is the baseband frequency
- Step #3: ensure the Tx laser is aligned with the Rx one. This permits an optimal monitoring of the signal-filter detuning
- Step #4: minimize the metric |M1|, hence filter penalties
• Experimental measurements
- Tx laser frequency known at +/- 1.5GHz and filter slot center at +/-2.5GHz
Public
What needs to be added
Monitoring & closed-loop systems: filter mitigation
22 © Nokia 2018 Public
What needs to be added
Monitoring & machine learning: architectures
Low latency High Cognition
Vendor A
Rx adaptation
Vendor A
Cloud
Program devices
Monitor
SDN controller
Learning & decision making
Vendor A
Program learning
Monitor
SDN controller
Cloud
Rx learning & adaptation
Learning
23 © Nokia 2018
Monitoring & machine learning: examples
What needs to be added
Public
Low latency High Cognition
QoT prediction “A learning living network”
[Oda et al., JLT’17] Vendor A
Program learning
Monitor
SDN controller
Cloud
Rx learning & adaptation
Learning
Vendor A
Cloud
Program devices
Monitor
SDN controller
Learning & decision making
ML at DSP level [Zibar et al., ECOC’15]
24 © Nokia 2018
QoT prediction with learning
Public
• Network margins (as defined in Augé et al., OFC’13):
- Unallocated margins – where transmission reach exceeds the transmission distance
- Design margin – unwanted, worst case QoT prediction (imperfect model + input uncertainties)
- System margins – time-dependent, fixed margins (e.g. polarization effects, ageing, network load)
• Many recent works on QoT prediction with learning
- Oda et al., JLT, vol. 35, no. 8, 2017
- E. Seve et al., OFC’17
- S. Yan et al., ECOC’17 PDP
- M. Bouda et al., JOCN vol.10 (1), 2018
- …
[Seve et al., OFC’17]
25 © Nokia 2018
• E. Seve et al., OFC’17
- QoT model, evaluation of power uncertainty
- Simulations with statistical error on measured power P
Examples
Public
• S. Oda et al., JLT 2017
- Experimental testbed with 6 ROADMs, 88 channels at 100Gbps with 50GHz spacing
- Monitoring BER
No learning
#Demands
SN
R e
rro
r (d
B)
0
-1
-2
1
2
3
QoT prediction with learning
Prediction instead of (worst-case) forecast
26 © Nokia 2018
Monitoring & machine learning: examples
What needs to be added
Public
Proactive fiber break detection
[Boitier et al., ECOC’17]
Low latency High Cognition
QoT prediction “A learning living network”
[Oda et al., JLT’17] Vendor A
Program learning
Monitor
SDN controller
Cloud
Rx learning & adaptation
Learning
ML at DSP level [Zibar et al., ECOC’15]
27 © Nokia 2018
[F. Boitier et al., ECOC’17]
Proactive Fiber Break Detection
Public
• To proactively detect fiber break to use cost-effective optical restoration
- Be as reliable (as 1+1 protection) and low cost (as in shared restoration)
- Use the transmission fiber as a sensor
- Unleash coherent receiver for monitoring
• We develop a real-time proof-of-concept with monitoring and learning
- We compute State-of-Polarizations (SOP) based on existing FIR filters
- We classify events at the DSP level to lower false alarms and re-route traffic in case of a risky event before the cut occurs
28 © Nokia 2018
[F. Boitier et al., ECOC’17]
Proactive Fiber Break Detection
Public
• Training phase
- Control & management plane
- 16548 events divided into training and test, with 10-fold cross-validation
- 4 different SOP events generated, usage of polarization scrambler for robustness
- We evaluate accuracy with naïve Bayesian classifier for various number of parameters
• Real-time measurements
- Small number of variables required for event classification
=> Easy to embed in real-time boards
- Reduce false alarms and avoid unnecessary re-routing of traffic
Real-time receiver board
Step #1
Calculate SOP
Step #2
Calculate rotation
speed
Step #3
Compare to
threshold
Step #4
Save SOP
during few sec
t
SOP
Alarm
Yes
Event
recognition
!
Embedded CPU in receiver board
29 © Nokia 2018
Real-time proof-of-concept
Proactive Fiber Break Detection
Elastic Tx
Node C Node B
Emulated Rx
Elastic Rx
SDN Controller
Node D
Node A Working path
Restoration path
30 © Nokia 2018 Public
Real-time proof-of-concept
Proactive Fiber Break Detection
31 © Nokia 2018
• Metro is the meeting point between telcos and OTTs with less stringent requirements in long reach / high capacity performance than core networks
Good playground for disruptive research
• Need to change perspective from “set & forget” to “easy to use & (re)-configure”
- Good news is that data plane is already deploying products with high level of flexibility
- Good news: many talks at OFC & ECOC on automation, online optimization
- Need for faster reconfiguration
• Unified control may be more challenging
• Machine learning is a natural evolution to
- Optical monitoring
- Traffic patterns observation
Predicting (deterministic models) instead of forecasting (uncertainty)
Public
Conclusions
Work partly supported by H2020 European project METRO-HAUL
33 © Nokia 2018
• Superchannel optimization example
Public
What needs to be added
Plug and play, monitor and optimize
F. Cugini, et al., “Towards Plug-and-Play Software-defined EONs: Field Trial of Self-Adaptation Carrier Spacing,” in Proc ECOC, 2015
Installation with QoT prediction
subcarrier packing Sequential shift
Monitor BER
Monitor BER => FEC limit reached
WSS reconfiguration
Increase #iterations of FEC decoder
SDN control + supervisory channel
34 © Nokia 2018
• Optical white box [M. De Lenheer, et al., Th1A.7, OFC’16], Architecture on Demand [N. Amaya et al, ICTON’11]
more flexibility to use hardware, open possibilities by software
• Chassis, hence backplane disappears but this has a cost:
- loss of flexibility with manual cabling between hardware elements
- Insertion loss of about 3.5dB due to a fiber switch matrix
• Such losses may be well-accepted in metro networks where the need for high performance is not always mandatory.
• But, back-2-back performance are key in metro networks to increase network capacity [D. Boertjes, Workshop flexible optical networks,ECOC’16]
Public
What needs to be added
Open architecture
