This document summarizes onboard rail networks and topology considerations. It introduces Westermo, a rail networking equipment provider, and their Viper and Ibex product families. It then discusses EN50155 compliance, topologies like those defined in IEC 61375 for consist networks and train backbones, and considerations for high availability and cyber security in rail networks.

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

2. 2
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

3. 3
▪ 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?

4. 4
▪ 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

6. 6

7. 7
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

8. 8
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

9. 9
Power Requirements
▪ 24 – 110V DC with EN50155 margins
▪ 10ms hold-up
▪ Polarity protection
▪ Redundant supply
▪ Triple isolation
▪ PoE power isolation

10. 10
Humidity
▪ 0-95% relative humidity (storage / operational)
▪ No moist build-up by using GORE-TEX ® membrane
▪ IP67 / IP65 / IP40

11. 11
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

12. 12
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

13. 13
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

14. 14
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

15. 15
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

16. 16
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

18. 18
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

19. 19
▪ 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

20. 20
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

21. 21
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

22. 22
Layer 2 Options
▪ Less than ideal
▪ No protection from data storms
▪ Limited cyber security protections
▪ Each consist must have a unique configuration

23. 23
▪ “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

24. 24