Authored by Paulo Paixão (EFACEC, Portugal)
The Metro-Rail market segment assumes a crucial importance in the EFACEC Engenharia e Sistemas (EFACEC) core business and for competing in this area EFACEC develops and integrates state-of-the-art systems that allow to supply Metro operators and infrastructure owners,
turn-key solutions such as Public Address, Video surveillance, Signalling, SCADA, Emergency Telephony or Automatic Vehicle Location. In such environments, several key aspects must be considered, involving Communications, Reliability, Security and high availability. Traditionally, for support Metro and Railway systems, the communications are based on private networks, typically with optical cable structures and to address the vehicles, solutions as Tetra Radio systems are often used.
In the HORSE project (horse-6g.eu) , EFACEC has defined as its main goal and also as its main challenge, to use future 5G/6G wireless solutions to support LRT Metro operations, replacing optical and tetra networks by a single common wireless solution.
Several challenges arise and the one related to cybersecurity, specifically concerned to vulnerabilities and threats against cyber-attacks is the more critical one, since it can cause disruptions in the system.
This challenge for using 5G wireless technology was initiated and researched at EFACEC through the European Horizon project 5Grwoth, where wireless 5G communications were used to support railways signalling operation, in particular in Level Crossings and its success can be achieved by the 5G PPP European recognition that considered the solution one of the Top 10 Trials and Pilots 
In the Horse project, it is considered to reach even higher levels of performance and recognition and to achieve such goals a Use Case (Secure Smart LRT Systems/SS-LRT) was defined and several scenarios, involving similar functionalities (Public Information systems and security systems) to those used in Metro systems of Dublin (Ireland), Bergen (Norway) or Odense (Denmark), will be deployed and validated, using, in the Horse context, 5G/6G future wireless networks.
Using private or public wireless networks, implies that the level of exposure to cyber threats is significantly higher than considering a private cable network and attacks such as Ransomware, Data related threats, Malware as well as DoS/DDoS, Phishing or Supply-chain can occur more frequently. Therefore, through the Horse project it is desirable to study and simulate the behaviour and the level of protection of a system, developing resilience, trust mechanism and strategies as well as smart security innovative capabilities that will leverage the use of 6G future wireless in metro operations.
The figure below represents a Metro Solution (stations and vehicles, shown in the left side, communicating with the Command Center using a 5G/6G network, shown in the right side), in the Horse context and using the Horse solution to detect and mitigate cyber attack through the resilience and smart security Horse platform features.
Therefore, adopting a HORSE solution can lead, in the future, to a unique network to support Metro/Rail operations, improving the convergence, integration, the resilience, and the level of security, benefiting from the cost reduction of maintenance and even the CAPEX of a Metro/Rail solution, assuring also the capability to support new type of services.