Retrofitting vs. New Purchase: Two Ways to Integrate Digital Systems in Buses and Rail

Why the Transition to IP Communication is Imperative

The previously used analog technology with serial interfaces is not designed for transmitting large amounts of data. In contrast, IP-based communication brings not only high bandwidth but also additional advantages like widespread availability, standardization, and system flexibility.

The central challenge in the era of digitalization lies in managing extensive data volumes. Data exchange must occur not only rapidly and efficiently but also in accordance with established standards. Furthermore, networking numerous participants from diverse locations is crucial, necessitating a robust network infrastructure.

To meet the demands of complex data networks, over the past decades, the network standard IEEE802.3, better known as Ethernet, has established itself as a leader. The Ethernet standard is realized through the implementation of an onboard network, where Ethernet switches play a significant role. The combination of these elements enables efficient real-time data transmission and ensures seamless integration of various devices into the network. IP systems of this nature enjoy considerable popularity due to their robustness, scalability, wide bandwidth, and high standardization.

The transformation towards IP-based and digitalized vehicles in public transport occurs in practice through two different approaches:

a) Continual retrofitting via vehicle procurement

b) Retrofitting of the existing fleet

Various criteria such as fleet size, time constraints, financial aspects, and technical requirements are pivotal in determining the choice of strategy.

Continual Retrofitting in Public Transport through Vehicle Procurement

One method of retrofitting involves the continuous procurement of new vehicles. Depending on the size of a transit authority, approximately 10% of a bus fleet is renewed annually. Depending on political climate goals for CO2 neutrality, this quota can be significantly higher. During procurement, buses are specified to be delivered with an integrated IP network infrastructure, including Ethernet switches and cables, by the vehicle manufacturer.

This approach offers the following advantages:

• Gradual transition: The transit operation can acquaint itself with the technology in the new vehicle and focus on establishing the necessary IT infrastructure and skilled personnel.
• The additional costs for an IP network infrastructure, consisting of Ethernet cabling and switches, usually amount to less than 0.5% of the total vehicle cost. In return, the new vehicles are prepared for future applications and do not require subsequent retrofitting.
• No substantial financial resources required

However, continual retrofitting has a central drawback: the duration. Assuming a 10% annual renewal rate, the retrofitting process takes 10 years. During this time, potentially two different systems—analogue and digital—may need to operate concurrently. This method of continual retrofitting is particularly suitable for transit operations with sufficient time to reorient their operations, recruit new specialized personnel, and familiarize themselves with IP-based systems.

Retrofitting: The Fastest Path to a Digitalized Vehicle Fleet

Retrofitting the existing fleet offers the fastest route to establishing IP-based vehicle communication and thus digitalizing data within the vehicle.

For a successful retrofitting process, the transit authority initiates a dedicated project and separately defines the network infrastructure in the tender. Precise planning of each phase and interdisciplinary collaboration between IT infrastructure, vehicle technology, and workshops are crucial.

Regarding the network infrastructure, four crucial steps are necessary for successful implementation:

1. Network Concept
   • Definition of network requirements
   • Selection of suitable network components
   • Testing the concept in the lab
   • Finalizing configuration specifications for the network

     >> More on this topic: Network Infrastructure in Public Transport Vehicles: Proof of Concept

2. Pilot Operation
   • Initial installation in selected vehicles
   • Testing and optimization during operation
   • Preparation for widespread deployment

     >> More on this topic: Network Infrastructure in Public Transport Vehicles: Pilot Phase

3. Rollout
   • Scheduled installation of components
   • Commissioning of the network infrastructure
   • Functional tests for all participants

     >> More on this topic: Network Infrastructure in Public Transport Vehicles: Rollout

4. Operation
   • Ensuring expected line operations
   • Maintenance-free use of the network infrastructure
   • Possibility for device renewal or updates in case of disruptions or network expansions

     >> More on this topic: Network Infrastructure in Public Transport Vehicles: Operation

The time required for retrofitting varies depending on the size of the transit authority and the number of vehicles, usually spanning a period of 6 to 24 months. Modernizing existing vehicles also offers several advantages, such as a shortened phase with two parallel systems, swift implementation of new functions like video surveillance, passenger counting, and dynamic passenger displays with live data uniform across the entire fleet, as well as flexibility and scalability. However, this approach demands both financial and human resources.

The decision for the suitable approach in your transit operation depends on a thorough consideration of the factors mentioned.

Individual Assessment for Successful Network Retrofitting in Transit Operations

While both options have their justifications, the decision for the optimal path should arise from the individual situation of the transit authority. The following key questions play a role:

1. What are the time constraints and guidelines from the city administration or politics?
2. What financial and personnel resources are required for network conversion?
3. Which systems exactly need to be digitized?
4. Are there grants or support available for network retrofitting?
5. How old are the vehicles on average, and what is the planned renewal rate for the coming years?

Our experiences collaborating with over 70 transit authorities and operators in the field of network infrastructure emphasize that there’s no such thing as an all-encompassing universal concept. Both small and large operations with fleets ranging from 10 to 1000 vehicles can smoothly plan and implement retrofitting or continuous upgrading. A reliable partner such as TRONTEQ is of crucial importance for the efficient and professional implementation of digital IP networks.