In response to the growing demand for reliable railway communication networks, 3onedata has introduced two series of rugged Ethernet switches that specially designed to meet EN50155, the onboard standard for electronic equipment, which encompasses not just EMC requirements but also shock, vibration, wide temperature range, humidity, and power supply variations.

3onedata EN 50155 Compliant Ethernet Switches TNS5500D/TNS5800D Series

The rugged TNS5500D Series and TNS5800D Series of EN 50155 Ethernet switches from 3onedata are designed for railway applications, including rolling stock and wayside installations. The switches use M12 connectors from Phoenix Contact to ensure tight, robust connections and guarantee reliable operation in industrial environments where vibration and shock are commonplace.

M12 Connectors - Robust Vibration-proof Connections

Both TNS5800D Series and TNS5500D Series provide 4 Gigabit M12 connectors with bypass relay function to ensure non-stop data communication in the event the switch stops working due to a power failure. They also use redundant power supplies to increase the reliability of your communications system, the two redundant power supplies work at the same time and back up each other, when one power supply powers off for some reason, the other one still works to ensure the continuous and stable power input, so there is no downtime at all. With bypass relay function and isolated dual power input, these two series switches can provide customers reliable and uninterrupted rail communication in rolling stock or moving vehicles.

Bypass Relay Function & Dual Power Input

The IPv4 is a 32-bit address, whereas IPv6 is a 128-bit hexadecimal address. IPv6 provides a large address space, and it contains a simple header as compared to IPv4.  The TNS5800D Series and TNS5500D Series of EN 50155 compliant Ethernet switches provides IPv6/IPv4 dual stack management to offer better addressing and security for large networks and help the railway facilities to step in the IPv6 era with the lowest investment as its network facilities need not be replaced or overhauled if the IPv6 network is set up.

IPv6 vs IPv4

Multicast transmission makes more sense and is more efficient than unicast transmission for some typical onboard applications such as onboard PIS, and it can reduce the load of information sources and optimize network resources. The TNS5800D Series and TNS5500D Series enable PIM-DM, and PIM-SM multicast routing and use IGMP snooping to prune multicast traffic so that it travels only to those end destinations that require the traffic, reducing the amount of traffic on the Ethernet LAN and improving network transmission efficiency.

Multicast vs Unicast

These two series of EN 50155 switches are designed with port flapping protection, loop protection and link aggregation, abnormal port will shut down automatically to prevent the impact from single port’s failure and ensure reliability of Ethernet network. Besides, 3onedata’s patented Link Aggregation Detecting together with Unidirectional Link Detection(UDLD) can shut abnormal aggregation link or disabled port to guarantee stable operation of Ethernet network.
The TNS5800D Series and TNS5500D Series of EN 50155 compliant switches deserve powerful troubleshooting, they support the recording of user logs, security logs, diagnostic logs, etc. The maximum memory reaches 10000+ logs, and it support a 7-to-30-day circular coverage, logs can be saved even when switch involved in an accident power failure. In addition, the switch can count and record the packets received by its CPU, and can support the statistics and records of 42 protocol packets such as routing, ring, multicast and timing, making it convenient for network administrator to trace the source of network failures.

Additional Features
A.Provides IPv6/IPv4 dual stack management
B.Provides up to 30 watts per PoE port with a total power budget of 120 watts per switch
C.Layer 3 models support RIP v1/v2, OSPF v2 and VRRP for router redundancy, up to 1024 routing entries can be configured.
D.Layer 3 models support multicast routing protocols such as Protocol Independent Multicast Dense Mode (PIM-DM) and Protocol Independent Multicast Sparse Mode (PIM-SM) to reach traffic forwarding of multicast groups.
E.Remote Authentication Dial In User Service (RADIUS) and IEEE 802.1X to enhance network security.
F.Access control lists (ACL) increase the flexibility and security of networking management.
G.Loop protection to prevent network loops.
H.Dynamic Host Configuration Protocol (DHCP) server and DHCP client can be used for
I.different IP address allocation strategies.
J.DHCP Snooping prevents unauthorized (rogue) DHCP servers offering IP addresses to DHCP clients.
K.DHCP relay allows DHCP communication between hosts and remote DHCP servers that are not on the same network.
L.SW-Ring (recovery time < 20 ms @ 250 switches), STP/RSTP/MSTP and ERPS for network redundancy.
M.Link aggregation allows increased reliability and availability, better use of physical resources, increased bandwidth and cost effectiveness.
N.SNMPv1/v2c/v3 for different levels of network management.
O.Link Layer Discovery Protocol (LLDP) for automatic topology discovery in network management software.
P.Configuring port statistics allows an administrator to detect network failures and analyze the cause.
Q.Internet Group Management Protocol (IGMP) snooping and GARP Multicast Registration Protocol (GMRP) for filtering multicast traffic.
R.VLANs can be assigned based on interfaces, MAC addresses, IP subnets and protocols to enhance subsystem’s confidentiality and network robustness.
S.Port mirroring for online debugging.

Click the model name and visit product page for more information and technical specifications of the TNS5500D Series and TNS5800D Series.


1.Metro Onboard Passenger Information System (PIS)

The Passenger Information System, PIS, is the operating tool responsible for providing real-time passenger information to passengers at stations, such as estimated arrival and departures times and emergency announcements. The main objective is to provide passengers a safe and comfortable travel experience.
Generally speaking, a metro onboard PIS includes three subsystems, Passenger Information Display System (PIDS), Public Address System (PA) and Closed Circuit TeleVision (CCTV). PIDS is used to display train diagram and arrival/departure information, PA systems with many speakers are widely used to broadcast arrival/departure information and necessary announcements, CCTV, also called Video Surveillance, is normally IP based in order to monitor carriages.
The EN 50155 switches from 3onedata use M12 connectors to ensure tight, robust connections, they can connect LCD displays, cameras, PIS controllers, CCTV controllers and other facilities. A TNS5500D switch is deployed in every carriage and driver’s cab to use link aggregation to form the redundant link, improving the bandwidth of backbone network and achieving network load balance. Besides, a layer 3 switch TNS5800D is deployed in the two train heads,it can connect onboard LAN and ground network through NAT, PIM-DM/SM multicast routing helps build a Multicast Distribution Tree (MDT) from ground multicast source to onboard PIS network, the layer 2 switch TNS5500D uses IGMP to establish multicast group memberships, LCD display obtains ground multicast information and displays real-time train diagram. Compared to unicast transmission, multicast transmission can utilize bandwidth more efficiently and reduce network congestion or packet loss.
The speakers and emergency alarm in PA subsystem are connected with onboard PIS controller by specific audio cable. Arrival/departure information is announced automatically, while alarm message is announced by the driver. The Ethernet switch deployed in the CCTV subsystem is required to be equipped with PoE function, the TNS5800D Series and TNS5500D Series of EN 50155 compliant switches provide up to 30W per PoE port, grant a steady and reliable source of electricity for IP cameras.

2.Tram Onboard Fare Collection System (FCS)

Compared with bus, tram has an advantage of higher passenger capacity, and the ticket price of tram is cheaper, the stop spacing of tram is shorter than metro’s. Combined with advantages of bus and metro, tram helps a great deal in easing traffic congestion.
The Tram Fare Collection System (FCS) is consist of IC card data center, route center, depot ticket terminal equipment, onboard ticket checking machine, etc. Ordinarily, a tram has three to five carriages, there are wired/wireless ticket checking machines in every carriage of the tram for passengers to make the payment easily.
3onedata provides wireless access point IAP3600S and M12 switch TNS5500D for the Tram Fare Collection System. The IAP3600S is used to transmit wireless ticketing data of the whole tram, the EN 50155 switch TNS5500D provides 8 PoE ports that compliant with IEEE 802.3 af/at, with  up to 30W per PoE port, this switch can power the IAP3600S through a network cable, greatly reducing the fault points. Besides, the TNS5500D can connect terminals such as passenger counting cameras, GPS and onboard controllers, and send the FCS data back to the ground network through the 5G wireless bridge.

About 3onedata
Headquartered in Shenzhen, founded in 2001, 3onedata has been dedicated to IIoT for 21 years, with rich professional experience of providing industrial communication solution and service for partners and customers worldwide. In 2020, 3onedata became the first IIoT company to be listed on Shanghai Stock Exchange (SSE) STAR Market, a milestone for our sustainable growth and development.
Innovation, Value and Honor are 3onedata’s core values, which guide our business strategy and operation. 3onedata attaches great importance to the overall development of the company, with continuous annual investments to ensure innovation in production, R&D and marketing in order to provide more competitive products in the market and support the success of our customers. Total Service System(TSS) is our unique operation model, providing the customer a feeling and experience of total service, which will lead to long-term effective development of 3onedata. From our persistent core values and competence in delivering great performance, we are confident in facing the uncertain future. 3onedata are looking forward to cooperating with you, for mutual benefits, and move forward together, on the way.

Business Contact: Mr. Frank Zhu, E-mail: