Onboard rail Ethernet switches and network topologies explained.

1. Onboard Rail Networks
Resilient Devices and Topology Considerations
6/24/2020
Dakota Diehl, Technical Director North America
Benjamin Campbell, Technical Support Engineer

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Overview
▪ Introduction
▪ Onboard Rail Networks
▪ EN50155
▪ Rail Specific Hardware
▪ Viper Family
▪ Ibex Family
▪ Crossing Existing Couplers
▪ High Availability Networks
▪ Onboard Rail Network Topologies
▪ IEC61375
▪ Other Possibilities
▪ Cyber Security

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▪ Founded in 1975
▪ Order intake: >55 Million USD Order Intake
▪ Number of employees: 350
▪ ~14% R&D spend
▪ Industry leading software and hardware
development force
▪ Production in Sweden with state-of-the-art
process control
▪ Sales and support units in 12 countries,
distribution partners in many others
Who is Westermo?

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▪ Local Support Office
▪ Office in Elgin, Illinois (Chicago area)
▪ Staff in multiple time zones
▪ Full Sales and Logistical Staff
▪ Local Technical Staff
▪ Support for North America
Westermo US Office
Westermo sales unit Westermo partner

5. Onboard Rail Networks

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Onboard Applications
System integrator or local sub-supplier (Vital applications )
▪ TCMS (Train Control Management Systems)
▪ IEC 61375
System integrator or local sub-supplier (non-Vital applications )
▪ Emergency phones system
▪ Passenger information systems
▪ Video surveillance
▪ Monitoring
Local railway admin
▪ Different projects running locally requires IDC products
▪ Often requires local approvals

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EN50155
▪ EN 50155:2017 is an international
standard covering electronic equipment used on rolling
stock for railway applications. (Wikipedia)
▪ Requires specialized Hardware
▪ Westermo Viper and Ibex families

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Power Requirements
▪ 24 – 110V DC with EN50155 margins
▪ 10ms hold-up
▪ Polarity protection
▪ Redundant supply
▪ Triple isolation
▪ PoE power isolation

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Humidity
▪ 0-95% relative humidity (storage / operational)
▪ No moist build-up by using GORE-TEX ® membrane
▪ IP67 / IP65 / IP40

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Vibration and Shock
▪ Vibration, shock and bump tests in operational mode
▪ Vibration (random)
▪ IEC 60068-64, 5-20Hz, 5h, 0.8 grms
▪ Shock
▪ IEC 60068-2-27, 100g, 6ms
▪ Bump
▪ 60068-2-27, 11g, 11ms

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Westermo Viper Family
▪ EN50155 Ethernet Switches and Routers
▪ Very Compact
▪ Westermo WeOS Operating System
▪ 8, 12 and 20 Port Variants
▪ Gigabit
▪ PoE
▪ Bypass Relays
▪ Support for IEC61375 ETBN on Applicable Models
▪ Dual Power Input
▪ Direct from Vehicle Power Source

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Westermo Ibex Family
▪ Swiss Made
▪ Westermo Neratec
▪ Full suite of Rail wireless solutions
▪ Train to Train
▪ Train to Ground
▪ Passenger Wifi
▪ Cellular Access
▪ EN50155
▪ Westermo Wireless OS

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Westermo Wireless Soultions
Train to Ground Train to Train
• Wireless transmission while the train is
on the move
• Wireless transmission when the train
stops at the Stations and Depot
• Inter-Carriage Link (Transparent
“wireless cable”)
• 380Mbit/s per link on 40MHz channel

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Even More Wireless Solutions
• Cellular transmission while the train is on the
move (LTE)
• Wireless transmission when the train stops
at the Stations and Depot (WiFi)
• Accurate positioning
• 802.11ac Wave 2 MU-MIMO enabling
high speed Wi-Fi coverage within
carriage with Dual-concurrent (5GHz +
2.4Ghz)
Onboard Wi-Fi Cellular & Positioning

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Crossing Existing Couplers
▪ Wolverine DDW-002-B1
▪ Up to 70 Mbps across existing coupler pins and wiring
▪ Based on IEEE 1901 EoP Technology
▪ Cost Effective communications in retrofit and referbismnet
projects
▪ Based on Viper Hardware
▪ Same Environmental and Power specs

17. Onboard Rail Network
Topology

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Topologies
▪ IEC 61375 Standard
▪ IEC 61375-2-5 (Train Backbone/TTDP)
▪ IEC 61375-3-4 (Consist Network)
▪ IEC 61375-2-3 (TCN Inauguration/TRDP)
▪ Other Possibilities
▪ Flat Layer 2 Networks

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▪ TCN (Train Control Network) Standard
▪ Originally defined MVB (Multifunction Vehicle
Bus) and WTB (Wired Train Bus)
▪ Modernized for Ethernet Communications
▪ Defined Topologies and Protocols
▪ TTDP – Train Topology Discovery Protocol
▪ TRDP – Train Realtime Data Protocol
▪ Ethernet Consist Network
▪ Ethernet Train Backbone
IEC 61375

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IEC 61375 Consist Network
Inter Consist Inter Consist
Consist 1 Consist 2 Consist 3
ETB
ECN
ETB
Node 1
(UUID 1111…)
ETB
Node 1
(UUID 2222…)
ETB
Node 1
(UUID 3333…)
ETB
Node 2
(UUID 1111…)
ETB
Node 2
(UUID 2222…)
ETB
Node 2
(UUID 3333…)
▪ Consist Network
▪ Ring Topology
▪ Westermo FRNT
▪ All devices have the same IP address in each Consist
▪ Consist Network does not cross couper
▪ Network Segmentation
▪ Layer Three

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IEC 61375 Backbone Network
Inter Consist Inter Consist
Consist 1 Consist 2 Consist 3
ETB
ECN
ETB
Node 1
(UUID 1111…)
ETB
Node 1
(UUID 2222…)
ETB
Node 1
(UUID 3333…)
ETB
Node 2
(UUID 1111…)
ETB
Node 2
(UUID 2222…)
ETB
Node 2
(UUID 3333…)
▪ Backbone Network crosses coupler
▪ Redundant Links managed by link aggerate
▪ Dead Car scenario managed by bypass relays
▪ Train topology and network inauguration managed by TTDP
▪ Each consist has a unique IP Network created by a specialized 1-1 NAT (RNAT)
▪ Network Segmentation
▪ Layer Three

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Layer 2 Options
▪ Less than ideal
▪ No protection from data storms
▪ Limited cyber security protections
▪ Each consist must have a unique configuration

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▪ “Made Easy” Configuration
▪ High level suite of security features
▪ Dedicated Vulnerability Management
▪ Dedicated Cyber Security Team
▪ Network Segmentation
▪ Layer Three
▪ Firewall
▪ Access and Authentication Control
▪ User Authentication
▪ Port Access Control
▪ VPN Encryption
Cyber Security

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