1. An introduction to: WDM for IP/MPLS service provider networks Anders Enström Product Manager Transmode Systems

2. WDM vs traditional fiber networks Transponders & Muxponders
Agenda
Basic WDM overview
CWDM & DWDM
Optical Amplifiers
WDM vs traditional fiber networks
Transponders & Muxponders
Flexible Optical Networks
Packet optical networks
Objective
Obtain a basic understanding of WDM technology and how it is used in networks

3. WDM Basics

4. The receiver converts the light pulses back to digital information
Optical Transmission
Transmitter
Receiver
Optical fiber
Optical transmission is the conversion of a digital stream of information to light pulses
The light pulses are generated by a laser source and transmitted over an optical fiber
The receiver converts the light pulses back to digital information

5. Wavelength Division Multiplexing
Transmitter
Receiver
Optical fiber
Wavelength Division Multiplexing (WDM) is based on the fact that Optical Fibers can carry more than one wavelength at the same time
The lasers are transmitting the light pulses at different wavelengths that are combined via filters to one single output fiber

6. Wavelength spectrum & attenation
Fiber
Optical fibers have different Attenuation values over the wavelength spectrum for lasers
Attenuation limits the reach of the optical pulses by reducing the optical power
Best attenuation (0.25dB/km) is around 1550 – 1610 nm

7. CWDM & DWDM

8. Coarse Wavelength Division Multiplexing
CWDM utilizes wavelengths from 1270 nm to 1610 nm
Maximum 16 wavelength channels per fiber
The bandwidth and spacing of the wavelengths allows for cheaper laser and filter technology compared to DWDM

9. CWDM Single-fiber & Fiber-pair
8ch per single-fiber 16ch per fiber-pair
8ch per fiber-pair
In commercial confidence

10. Dense Wavelength Division Multiplexing
CWDM
Outside
DWDM-band
DWDM
L-band
DWDM
C-band
The DWDM spectrums have more narrow bandwidth and spacing compared to CWDM
Increases total number of channels (typically 80) but lasers and filter components are in general more expensive
The ”C-band” is the most used due to the availability of Optical Amplifiers

11. The choice between CWDM & DWDM is typically based on:
Summary CWDM & DWDM
The choice between CWDM & DWDM is typically based on:
Distance to bridge
Number of channels needed
Data rates used
Flexibility and expansion
In general, CWDM is a cheaper technology more suitable for smaller aggregation networks in metro or access, for data rates up to 10G and reach up to 100km per span
DWDM is a slightly more expensive technology suitable for larger backhaul networks with complex traffic matrix and higher capacity, with data rates up to 100G and reach up to 3000 km

12. Optical Amplifiers

13. Amplifier stations typically each 80-100km
Optical Amplifiers
100km
100km
Without amplifiers the reach is limited to km before electrical regeneration
Optical amplifiers boosts the attenuated wavelengths and are more cost efficient than electrical repeaters
Amplifier stations typically each km
Depending on signal types and fiber characteristics, Amplified DWDM reaches typically up to 1500 km

14. Optical networks with amplifiers
OK up to 80km
SDH
SDH
What if the link is 240km?
SDH
80km
What if you have optical amplifiers?
SDH
80km
What if you want more channels?
SDH
80km
Restricted

15. Summary Amplified networks
Amplifiers are used in DWDM networks and increases the reach of the optical signals up to 3000 km
Amplifiers are a better choice than electrical repeaters and are usually distributed each km
Amplifiers and DWDM filters are the two basic building blocks for a powerful DWDM network

16. WDM vs traditional fiber networks

17. Dark fiber vs passive and active WDM
Dark fiber solution
+ low cost interfaces
+ no cost for passive equipment
high cost for fiber rental (one service per fiber)
long provisioning times
less flexibility in the optical layer
short reach
Passive WDM solution
+ no transponder cost
+ low cost for fiber rental
+ short provisioning times
only possible for short distance
no management or performance monitoring
Active WDM solution
- transponder cost
+ low cost for fiber rental
+ short provisioning times
+ transponders and client equipment could be in different locations
+ management or performance monitoring
+ aggregating services in muxponders for better wavelength utilisation
+ advanced networking functions, e.g. Protection, FEC, ROADM
Restricted

18. Traditional networks (ring example)
Cascaded nodes leads to complex redundancy schemes
Different services (Ethernet, SDH) requires separate fibers or complex and expensive equipment (Pseudowire, Ethernet over SDH)
Shared resources per fiber for all nodes
Same type of equipment and uplink interface in all nodes

19. WDM aggregation (ring example)
Easy mixing of service types (SDH, Ethernet, SAN etc.) per node
Redundancy per individual channel
Dedicated resources per node – no sharing!

20. Transponders & Muxponders

21. Transponders & Muxponders
SDH/ SONET
IP Router1 ʎ3
WDM link
WDM Node
Mux/Demux ʎ2
Transponder ʎ1
IP Router2
ʎ1 ʎ2 ʎ3
Muxponder

22. Generates the WDM wavelength
Transponder
Client signal
Digital
Wrapper
WDM
wavelength l
Generates the WDM wavelength
Line side
Client side
Transponder
Client side ʎ
Line fiber
Line side framing enables performance monitoring, management channels and increased reach with FEC
Client system

23. Generates the WDM wavelength
Muxponder
Client side
SDH
Client signals
Digital
Wrapper
WDM
wavelength FC
Ethernet
Muxponder
Client side
Line side l
Generates the WDM wavelength
Client systems
Client systems ʎ
Line fiber
Line side framing enables performance monitoring, management channels and increased reach with FEC

24. Summary Transponders & Muxponders
Transponders and Muxponders provides wavelength conversion from client to WDM signal
A Transponder maps a single client to a single WDM wavelength
A Muxponder multiplexes several lower speed client signals to a higher speed WDM wavelength, thus increasing the network capacity
The digital framing of a line signal from a Transponder or Muxponder provides service monitoring, management connectivity and increased reach
The broad range of available Transponders & Muxponders enables cost efficient solutions for both CWDM & DWDM

25. Flexible Optical Networks

26. ROADM networks ROADM – Reconfigurable Optical Add/Drop Multiplexer
Used for increased flexibility in the optical paths
Services can be redirected upon failure or capacity constraints
Capacity can be increased dynamically per node

27. Basic ROADM principles
Mux
Mux

28. Flexible Optical Network – Key Components
4/17/2017
Flexible Optical Network – Key Components
Multidegree ROADM
Enables dynamic switching of services and reconfiguration of capacity in the network
8D ROADM
8D ROADM
4D ROADM
2-D ROADM
Enables scalable growth of allocated capacity per add/drop node
8D ROADM
8D ROADM
2D ROADM
Colorless MDU
Enables scalability and ”lambda-free” planning and installation
Each key component is there to lower the operational cost and shorter the service provisioning time.
The multidegree ROADMs in the network enables flexible commissioning of new services across the network without manually visit the patch-through sites.
The 2D ROADM enables an add-drop node to be upgraded and adjusted with capacity at any time, lowers the planning cost and any future replanning of capacity
The colorless MDU allows a lambdafree planning and installation at the sites, no waste of Colored ports if the wavelength is occupied elsewhere. No need for skilled onsite engineers, use any available MDU port.
The tunable laser is also a part of the lambdafree planning and installation, as well as an important part for lowering the sparepart cost. It also enables, in combination with the colorless MDU, a total reconfiguration of the installed service, for instanse redirecting a service due to relocation or redundancy or lambda conflicts.
Tunable laser
Enables dynamic reconfiguration of services down to the wavelength
Limited

29. Summary Flexible Optical Networks
ROADM’s provide more flexibility compared to fixed filters
A wavelength can be redirected to another path if necessary
Capacity planning becomes easier with dynamic expansion of add-drop wavelengths
Remote software control – no site visits required
Using ROADM’s, colorless filters and tunable lasers provides extensive flexibility
Efficient reuse of deployed investments

30. Packet-Optical Transport Overview
4/17/2017
Packet-Optical Transport Overview

31. Layer 1 Transport  Packet Optical Transport
4/17/2017
Layer 1 Transport  Packet Optical Transport
Layer 1 Transport
Most suitable for:
Carrier internal infrastructure
Wholesale services
Characteristics:
Point-to-point, fixed speed
100% transparent (what goes in goes out)
No service priority separation
IP Provider Edge Router
~200M each
3 x1G 1G
10G
10G
10G
S 5G
10G
Mobile
Packet Core
1+1+1G
200M 1G
Service = client interface
Wavelengths or sub-channels for each service
Packet-Optical Transport
Most suitable for:
Business Ethernet services (E-Line, E-LAN, …)
IP access network
Video distribuiton
Characteristics:
Per-service routing, including multipoint
Aggregation and QOS separation of services
Flexible service rates
IP Provider Edge Router
~200M each
3 x1G
a,b,c
10G
d,e
10G
10G d
S 5G
a,b,c e
Mobile
Packet Core 1G
200M 1G
Service definition not tied to interface speed
Services prioritized and aggregated within network
Confidential

32. Native Packet Optical 2.0 for core agnostic service delivery
MPLS-TP over Ethernet
Native Ethernet
Cisco
Juniper
Alcatel
Ericsson
Packet over OTU
MPLS
(LSRs LERs)
IP Router
Mobile SGW
L3 Services
Internet
L3VPN
IPTV
L2 Services
E-Line
E-LAN
E-Tree
E-Access
Ethernet (SVLAN, ERPS, …)
Mobile services 3G
LTE
OTN
(switching grooming)
WDM foundation - Flexible Optical Networks
Core network
agnostic
Confidential
Restricted

33. Transmode L2 Solutions EMXP EDU NID iSFP-TDM Carrier Ethernet Services
4/17/2017
Transmode L2 Solutions
EMXP
Broadband aggregation
Carrier Ethernet
Services
EDU
Mobile backhaul
L2 Packet
Transport
Business Ethernet Access
Flexible ROADM- based WDM
NID
Legacy Services (TDM)
iSFP-TDM
Confidential

34. Summary

35. Summary
WDM technology will increase the ability to scale a network with more capacity without using more fibers
CWDM for smaller aggregation networks
DWDM for larger and more flexible networks
Flexible optical networks will enhance your network growth and reduce opex
ROADM based networks superior in scalability and flexibility
Integrated L2 functionality will give you the ability to sell advanced services directly over the fiber network and reduce the cost of routers and switches
MPLS-TP and CE2.0 services on a wavelength

36. Thank you!