ONBOARD COMUNICATION INFRASTRUCTURE

ETB – ETHERNET TRAIN BACKBONE
A Gigabit Ethernet Train Backbone network is used for communication between dynamically coupled units / consists. ETB inauguration handled by ETB Nodes (ETBN) automatically detects any changes in ETB topology, adapts the addressing and informs applications in the vehicle network.
ETBN also handles the routing of data packets between vehicle and train networks. Its high performance ensures there is no bottleneck even for demanding applications. Routing is automatically configured based on inauguration results.

ECN – ETHERNET VEHICLE NETWORK
A gigabit network with ring topology interconnects High Performance Computer network devices in a vehicle or consist (fixed unit). Other devices based on High Performance Computer platform, such as an ATO control unit or NVR, may be integrated directly into the ring network. This provides a edundant connection to the network while saving end device ports.
High Performance Computer Ethernet switches support configuration profiles selected by HW configuration pins integrated into the power supply connector. This greatly simplifies deployment and service operations in networks spanning over multiple vehicles. An Integrated DHCP server with a port-based address allocation further simplifies the deployment and configuration of devices with multiple instance – e.g. IP cameras

NETWORK AVAILABILITY
The complete network is designed as fully redundant with no single point of failure. Ring topology of the vehicle network with specialized ring control protocol ensures 50ms recovery time in case of single line / switch failure. Bypass relays in each High Performance Computer Ethernet switch further increase the availability of the network even during multiple failures. Connection between the vehicle network and train backbone is handled by redundant ETBNs operating in active / standby mode.
Standby ETBN continuously monitors the active node and assumes control over all the functions in case of active node failure.
The redundancy is completely transparent to end devices. The train backbone has a linear topology. Each ETBN is equipped with bypass relays on the ETB ports which ensures continuous ETB operation when one node is powerless or not operating. ETBN continuously monitors both ETB lines in each direction and redirects the traffic as necessary in case of line failure.

ONE NETWORK FOR MULTIPLE SYSTEMS
One physical network is used for multiple onboard systems. This approach allows the reduction of the number of network elements and cabling; therefore, optimizing initial and LCC costs in addition to increasing the overall availability of the vehicle. Individual systems are separated by VLANs.
Data exchange between systems (VLANs) is handled by a redundant high performance router with advanced firewall capability. Quality of Service policies implemented in each network element guarantee sufficient bandwidth and low latencies for critical systems (TCMS, voice, video streams).

DIAGNOSTICS
High Performance Computer network devices provide information for fast runtime diagnostics of the train backbone, the vehicle ring and individual end device connections.
Detailed statistical counters are also available for each port, which can be used for further network analysis. All diagnostic information is provided via SNMP and TRDP services.