The Ethernet Switch and its Role in Buses and Trains
22 Apr, 2021

Ethernet switches are essential components of digital IP networks in public transport vehicles, enabling connectivity between various devices such as ticket validators, cameras, and board computers. These switches operate using the standard Ethernet protocol and are commonly found in buses, subways, and trams. In this article, we will explore the unique features of Ethernet switches designed for public transport networks.

For error-free communication between onboard devices, network infrastructures in public transport vehicles must be secure and stable. The Ethernet switch plays a crucial role in this context as it acts as a “control center” for distributing and combining data streams. It distinguishes connected devices based on individual IP addresses and forwards data or Ethernet frames to the correct recipient through the appropriate connection (port).

Switches for public transport vehicles vary in external features such as design, number, and type of Ethernet ports. However, the most significant differences are in the type of power supply and configuration options, which affect the overall performance and reliability of the on-board network. As a result, it is essential to choose a high-quality Ethernet switch that is specifically designed for public transport applications to ensure the best possible communication between onboard devices.

Physical Features of Ethernet Switches for Buses and Trains


Ethernet switches can be found in various settings, including data centers, industrial facilities, and home networks. Although they serve the same purpose, switches can differ significantly in terms of their physical characteristics. Specifically, Ethernet switches designed for public transport are noteworthy due to their lightweight, compact, and robust design. These features have proven particularly advantageous in the context of tight spaces and high levels of vibration in public transport vehicles.

Connection types

Ethernet switches designed for use in public transport vehicles may feature alternative types of connectors. Instead of the commonly used RJ45 connectors found in many networks, many public transport companies prefer Ethernet switches with M12 connectors. The latter have demonstrated superior performance in the challenging conditions of vibration, shock, extreme temperatures, and temperature fluctuations commonly found in buses and trains. A stable connection is essential to ensure secure and uninterrupted communication between onboard devices.

Powering Onboard Devices with Ethernet Switches

In an onboard network, each device must be supplied with power. Transport operators have two options to choose from for this:

  1. Connect each device individually to a power source.
  2. Use Power over Ethernet (PoE) technology and supply power through the switch. With PoE, end devices can receive up to 30W of power directly through the network cable. This method of power supply allows for simultaneous data transmission and power supply without any interference. It eliminates the need for additional cables, making installation and maintenance easier.

Ethernet switches with PoE technology are labeled accordingly. At TRONTEQ, all devices are available with or without PoE, ensuring compatibility with a wide range of public transport applications in buses, trains and trams. 

 Qualitative Features of Ethernet Switches for Public Transport

Management capabilities

Managed switches go beyond simply connecting Ethernet devices and offer additional features to keep better track of the onboard IP network in buses and trains. These switches provide intelligent functions like management, configuration, monitoring, and troubleshooting of network problems, which can all be done remotely through a web browser user interface or API access. Using managed switches in the topology of an IP network ensures better control and performance.

On the other hand, unmanaged switches do not offer any management capabilities and only allow connected devices to communicate with each other. They are a simple way to add additional ports to the network and are easy to set up – all you have to do is plug them in, and they will perform their functions. Unmanaged switches are ideal when remote maintenance and diagnostics are covered by other network participants.

Transmission speed

Ethernet connections can vary in terms of their transmission speeds. Fast Ethernet switches offer speeds of up to 100 Mbit/s, while Gigabit Ethernet ports can transmit up to 1000 Mbit/s. To put this into perspective, consider the following example: downloading an HD movie at 100 Mbit/s takes about 9 minutes, whereas at 1000 Mbit/s it takes less than a minute. The bandwidth required by onboard devices in public transport vehicles is an important consideration when choosing the appropriate switch.

TRONTEQ offers a wide range of M12 Gigabit Ethernet switches to cater to the specific requirements of different types of IP networks in buses, trains, and trams.

What Distinguishes an Ethernet Switch from a Router?

In public transport vehicles, switches and routers play important roles in ensuring seamless communication between onboard devices and the outside world. While switches are responsible for distributing and managing data traffic within the onboard network, routers are used to connect the vehicle to the internet and enable data exchange with external networks such as control centers or other vehicles.

So, what distinguishes a network switch from a router? In simple terms, switches operate at the data link layer of the OSI model (learn more about the technological requirements for digitalization in public transport here) and are responsible for forwarding data packets within a network, while routers operate at the network layer and are responsible for routing data between different networks. This fundamental difference in functionality makes switches ideal for creating local area networks (LANs) within public transport vehicles, while routers are necessary for establishing wide area networks (WANs) that connect vehicles to the internet or other external networks.

Ethernet Switches: Key to Digitalization in Public Transport Vehicles

Ethernet switches play a crucial role in enabling digitalization in public transport vehicles as intermediaries within IP networks. Designed specifically for transportation, these switches are compact, robust, and feature shock-proof M12 connectors. With Fast Ethernet and Gigabit ports, they can support data-intensive network architectures. Moreover, switches with Power over Ethernet (PoE) technology can power connected devices. Intelligent managed switches offer additional features such as remote control of the entire network.

Our products are fundamental for the digitalization in public transport. ROQSTAR M12 Ethernet Switches provide the network infrastructure for e-ticketing, passenger counting systems (PCS), dynamic passenger information (DPI) and closed-circuit television (CCTV).


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