Utviklingstrekk innen fiberoptisk telekom teknologi –
løsninger for verdensomspennende internettforbindelser
Steinar Bjørnstad CTO TransPacket/
[email protected]
Institute of Telematics
Norwegian University of Science and Technology
Optical Telecom networks
The ultimate capacity across
land and sea –
Efficient utilization required
TRANSPACKET
Fibre-cables are spanning the world
Source: RAMPART
Outline
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Utilizing the fibre: Transmission performance race
How much capacity is actually needed?
Utilizing available capacity: Optical networking
Software defined optical networks?
The performance race
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Bandwidth utilization
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Latency
–
–
–
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Physical layer: Fibre bandwidth utilization (bit/s/Hz)
decides total capacity: Gigabit per second (Gb/s)
Logical layer: Aggregation and switching efficiency
5 Microseconds/km transmission delay
Low latency increasingly important
Shortest route
Longest distance - highest capacity
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–
With repeaters (optical amplifiers)
Unrepeatered and/or remotely pumped optical amplifiers
Fibre has unique properties
25 THz bandwidth available with low loss
Enables Terabits of bandwidth over
thousands of kilometers
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Optical fibre loss spectre
Loss (dB/km)
0,5
0,4
0,3
25 THz
0,2
0,1
0
1200
1300
1400
1500
Wavelength (nm)
1600
Wavelength Division Multiplexing
Wavelength Division Multiplexing
fiber
i
kapasitet
(WDM), mangedobler
(WDM)
2,5 Gb/s =
30000
pr fiber
1 kanal
1 Før:
channel
pr fiber
Terminal
Fiber
11
11
11
11
44
11
11
44
Up to
Opptil
20 000 000
Electronic/electrooptical
Regenerator
WDM:
WDM:
4-128
4-128 kanaler
channels
pr fiber
pr fiber
11
Earlier
Tidligere utbygging
Nåværende
utbygging
11
Now
22
22
33
33
44
44
Optical
amplifier
Optisk forsterker
Demultiplekser
Multiplekser
WDM increases bandwidth utilization and total capacity
Optical amplifiers simplifies the system
Trends in WDM transmission
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Increasing bitrate in each WDM channel
Increasing spectrum efficiency (more bits per optical
Hz)
Currently in new systems: 100 Gb/s in each channel
Modulation format is key
Modulation formats 100 GB/s
Lach et.al.
Modulation formats 100 GB/s
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Minimum channel spacing (Bandwidth utilization)
Maximum transmission distance
Lach et.al.
Modulation formats 100 GB/s
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Minimum channel spacing
Maximum transmission distance
Lach et.al.
Preferred format
Two bits/s/Hz
Transmission capacity in optical fiber (lab)
100Tbit/s
D.J. Richardson et al., Nature Photonics, v. 7 p. 354, 2013
Transmission capacity in optical fiber (lab)
Multicore fibre is next? Current record is: Pb/s
D.J. Richardson et al., Nature Photonics, v. 7 p. 354, 2013
Repeatered versus unrepeatered
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Active amplifiers along the link: Repeatered
Laser &
modulator
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Optical
Amplifier
Optical
Amplifier
fibre
fibre
100 km
100 km
Optical
Amplifier Receiver
fibre
100 km
Active amplifiers at end-points: Unrepeatered
Laser &
modulator
fibre
fibre
fibre
Receiver
Currently > 500 km
Raman amplifier
Raman amplifier
World records unrepeatered:
Long distance/high capacity
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Unrepeatered simplifies combined fibre and powercable
More than 500 km reach with 4 X 100 Gb/s
More than 400 km reach with 150 X 100 Gb/s
12 - 48 pairs of fibre in a cable
–
–
400 km: 180 – 720 Tb/s
500 km: 4.8 – 19.2 Tb/s
Internet HUB top 3 list
Short name
DE-CIX
Throughput
Maximum
(Gb/s)
Germany/USA
4859
AMS-IX
Netherlands
4242
2486
UK
3043
2122
LINX
Country
(location)
Throughput
Average
(Gb/s)
2780
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Global IP traffic growth
10x MOBILE
132 Exabytes/month (2018)
400 Tb/s = 4000 X 100Gb/s
6x VIDEO
3x DATACENTER
Network traffic growth 2014 - 2019
Market drivers optical networks
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Fibre to the Home (FTTH)
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Mobile networks
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Video applications (E.g. Netflix)
Increased density of mobile base stations
Fibre to the base-station
Datacenter communication
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Between datacenters
Connecting the datacenter to Internet
Optical – datacenters - applications
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Between datacenters
–
–
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Connecting to Customers (Internet)
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Medium distance
Long distance
Long distance
Within datacenters
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Short distance
Between racks
Optical networking
Switching at the optical layer:
Utilizing available transmission capacity
Optical networking & Optical switching
connecting several sites
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Many wavelengths and high bitrates
Optical switching enables scalable networks
Compact and low power switching
WDM fibre-ring with optical switching and resiliency
OADM
OADM
OADM
OADM
OADM
Optical add/drop multiplexer (OADM)
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A logical mesh network can be created on top of a
physical ring
Bypass traffic is processed optically
Specific wavelengths are added/dropped
OADM
OADM
OADM
Bypass
traffic
Drop
traffic
OADM
OADM
Optical switching
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Reconfiguration from a management system
Dynamic load balancing
Reconfigurable OADM (ROADM)
Wavelength Selective Switches (WSS): Crossconnection of wavelengths between several fibres
I1
U1
I2
U2WDM
I3
U3
I4
Outputs
Bølgelengde
Konverter
Optical
Optisk krysskopler
crossconnect
U4
What is next?
Future trends
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Higher bitrates in WDM channels
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Increased flexibility in optical networks
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100 Gb/s today, 400 Gb/s next, then 1 Tb/s
Increasingly advanced modulation formats
Modulation format and bitrate according to optical
path capability
Gridless allows variable width of WDM channels
Network control
–
Optical network deliver resources on demand from
users and upper layers
Controlling the optical network
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Network management system (NMS) working
across vendors and network layers is required
Setup and tear down of wavelengths according to
capacity needs
OADM
OADM
OADM
NMS
OADM
OADM
Controlling across network layers
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Applications triggers resource usage on servers
Server communication triggers network capacity
needs
IP- routers requires capacity from the optical
network
Optical network must deliver resources on demand
from upper layers
Controlling across network layers
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Applications triggers resource usage on servers
Server communication triggers network capacity
needs
IP- routers requires capacity from the optical
network
Optical network must deliver resources on demand
from upper layers
Software defined networks (SDN)?
SDN goals
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Centralized control of network resources
Control across network layers
Control independent of equipment vendor
SDN Multidomain control
R. Vilalta et.al. ECOC 2015: First experimental demonstration of distributed cloud
and heterogeneous network orchestration with a common Transport API for E2E
service provisioning and recovery with QoS
2015 - ID: 1061
Control Orchestration Protocol (COP) for communication with controllers for
each domain and vendor.
B)
A)
C)
Summary
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Optical Fibre enables ultimate capacity – ahead of
current transport needs
Capacity and maximum distance without repeaters
increases steadily
Control across vendors and protocol layers: Is
Software Defined Networks (SDN) the solution?
Capacity utilization is the key – achieving cost
efficient networks