Global Railway Signalling Systems: Current Status and Future Evolution

1. Executive Summary

• This report presents a comprehensive overview of the current status and anticipated evolution of global railway signalling systems, with a specific focus on the European Rail Traffic Management System (ERTMS) Level 2. The railway signalling sector is a critical component of modern transportation, increasingly influenced by the need for enhanced safety, interoperability, and operational efficiency. Recent analyses indicate that the global signalling market is expected to exceed USD 8 billion by 2035, driven primarily by urbanization and technological advancements. Key findings highlight the effective integration of Communication-Based Train Control (CBTC) systems, which enhance capacity and safety, as well as the deployment metrics for ERTMS Level 2, illustrating significant improvements in operational performance across various European nations.

• The report highlights the progress of ERTMS Level 2 deployment, with over 25, 000 km of track planned for modernization by 2035, demonstrating collaborative efforts among EU member states. Additionally, regional case studies reveal valuable insights into successful implementations of signalling technologies, particularly in South Korea and their KTCS-2 system. These findings collectively underscore the imperative for ongoing investment and innovation in signalling technologies, aiming for a seamless, efficient, and sustainable future for rail transport.

2. Introduction

• In an age characterized by rapid urbanization and the pressing demand for efficient transportation solutions, the global railway signalling landscape is on the cusp of a transformative evolution. With railways being a pivotal alternative to road transport and air travel, understanding the complexities and innovations within railway signalling systems has become paramount for industry stakeholders. As transportation networks grow in complexity, enhancing safety, reliability, and interoperability through advanced signalling technologies has never been more critical.

• The purpose of this report is to provide a comprehensive review of current railway signalling technologies worldwide, with a special emphasis on the deployment of the European Rail Traffic Management System (ERTMS) Level 2. This report seeks to address core questions regarding the effectiveness of various signalling principles and technologies, as well as their implications on operational performance. Section by section, we will examine traditional frameworks alongside modern innovations such as Communication-Based Train Control (CBTC) and their increasingly significant role in the evolution of railway operations.

• Furthermore, the report will delve into the deployment plans for ERTMS Level 2 across EU member states, evaluating the operational performance metrics and case studies that illuminate both achievements and challenges faced in these implementations. By providing a structured analysis grounded in multi-perspective insights, this report aims to equip decision-makers and industry professionals with the knowledge required to navigate a rapidly changing railway landscape.

3. Global Railway Signalling Landscape

• The railway signalling landscape is undergoing a transformative evolution driven by the need for enhanced safety, efficiency, and interoperability across increasingly complex rail networks. As urbanization escalates globally and the demand for rapid transit grows, innovative signalling systems have become crucial in redefining rail operations. Consequently, understanding and navigating the intricate frameworks of railway signalling principles has become imperative for stakeholders in the transportation industry.

• The complexities of railway signalling systems are not merely technical; they encompass substantial economic and social implications. Efficient signalling systems enable uninterrupted cross-border train operations, directly impact service reliability, and influence public perception of rail transport as a viable alternative to road travel. This comprehensive landscape includes traditional methods like fixed-block systems, as well as cutting-edge technologies such as Communication-Based Train Control (CBTC). Exploring these various systems illuminates their roles in the broader context of railway advancement.

• 3-1. Overview of major signalling principles (fixed-block, moving-block, ATP, ATS, CBTC)

• Railway signalling relies on a fundamental distinction between fixed-block and moving-block systems. Fixed-block signalling, the conventional approach, uses predefined sections of the track where trains can safely operate without conflicting with others. In contrast, moving-block signalling allows for real-time train tracking and spacing adjustments, significantly increasing track capacity and service frequency. This evolution in signalling paradigms is crucial for urban rail networks needing to maximize throughput amid rising demand.

• Advanced Train Protection (ATP) systems introduce automated safety measures, ensuring that trains do not exceed speed limits or move into occupied blocks by incorporating efficient braking systems that can respond autonomously. In line with ATP, Automatic Train Supervision (ATS) systems enhance operational efficiency by managing train schedules and coordinating movements across different network segments, ensuring punctuality and reliability in operations.

• Communication-Based Train Control (CBTC) marks a considerable leap in the evolution of signalling technology. By utilizing real-time communications between trains and trackside controllers, CBTC systems allow for more adaptive and efficient management of train movements, minimizing the risk of accidents. This paradigm shift supports seamless integration with modern technologies, such as automated train operations, which herald the future of rail transport, offering far greater reliability and flexibility than traditional signalling mechanisms.

• 3-2. Regional deployments in Europe, Asia, North America

• In Europe, the deployment of the European Rail Traffic Management System (ERTMS) showcases a comprehensive approach to standardizing railway operations across member states. The implementation of ERTMS facilitates seamless cross-border train operations, addressing the existing inconsistencies among various national signalling systems. Countries such as Germany, France, and Spain are at the forefront of integrating ERTMS while gradually phasing out older technologies, reflecting a broader trend towards modernization.

• Asia exhibits a diverse railway signalling landscape, with countries like Japan and South Korea leading in the adoption of advanced signalling technologies. South Korea's KTCS-2, developed as a domestically tailored ATP system, leverages local innovations to enhance safety and efficiency. This system not only promises superior reliability compared to traditional imports but also positions South Korea as a burgeoning player in the global railway technology market, offering systems poised for export to other regions, particularly in Southeast Asia.

• Meanwhile, North America presents a unique context where signalling systems must contend with extensive freight networks alongside passenger services. While advancements like Positive Train Control (PTC) enhance safety, the complexity of integrating these systems within existing infrastructure poses significant challenges. The North American model serves as a case study in balancing modernization with operational realities, revealing pathways for potential technological advancements to coexist with traditional practices.

• 3-3. Key standards and integration models

• The railway industry is characterized by various standards and integration models aimed at harmonizing operations across different regions and technologies. Standardization such as ERTMS in Europe plays a pivotal role in ensuring interoperability among various national systems. The push for standardization not only addresses safety concerns but also facilitates investments in infrastructure, as stakeholders can rely on well-defined protocols and specifications.

• Additionally, the integration of advanced technologies such as the Internet of Things (IoT) and Artificial Intelligence (AI) into signalling systems holds transformative potential. These innovations enable real-time monitoring and predictive maintenance, optimizing the performance of signalling infrastructures. By employing data analytics, operators can preemptively address maintenance issues, reducing downtime and enhancing overall network reliability.

• Moreover, as railway signalling systems evolve, it's imperative to consider collaborative frameworks that enable knowledge sharing and technological alignment across borders. Models that promote joint investments in research and development, along with harmonized regulatory practices, are essential in solidifying a connected global railway ecosystem. In this dynamic interplay of technology and regulation, future advancements will pave the way for safer, more efficient, and environmentally sustainable rail systems.

4. Future Trends and Technological Evolution

• As we stand on the brink of a new era in railway technology, the transformation of traditional signal systems through innovative advancements is paramount. The adoption of sophisticated communication-based systems, such as Communication-Based Train Control (CBTC), represents a decisive shift in enhancing safety, efficiency, and operational reliability across global railway networks. The growing integration of artificial intelligence (AI), data analytics, and predictive maintenance strengthens these systems, heralding a future where real-time decision-making capabilities are paramount, and failures can be predicted before they disrupt the service.

• Recent assessments indicate that the global railway signaling market is projected to surpass USD 8 billion by 2035, reflecting a compound annual growth rate (CAGR) of approximately 3.27% from 2025 to 2035. Central to this growth is the increasing demand for safe, reliable, and efficient transportation solutions, fueled by rising urbanization and the urgent necessity for modernized railway infrastructures. Consequently, understanding these emerging technologies is not merely an academic exercise; it is an essential component for stakeholders aiming to navigate the evolving landscape of railway transport.

• 4-1. Emergence of communication-based train control (CBTC) and moving-block operations

• Communication-Based Train Control (CBTC) is revolutionizing the operational protocols of urban transit systems worldwide. CBTC employs continuous real-time communication between trains and control centers, enabling dynamic management of train movements and facilitating higher frequency and capacity on existing lines. Unlike traditional fixed-block systems, which rely on predetermined intervals and fixed signaling, CBTC systems implement moving-block operations that allow trains to operate closer together as their positioning is continuously monitored and adjusted based on real-time data.

• The adoption of CBTC technology has already demonstrated impressive results in cities like London, Paris, Singapore, and New York, where increased service frequency has led to enhanced passenger satisfaction and reduced travel times. For instance, the deployment of CBTC systems has allowed for up to 40% reductions in headways, significantly increasing the capacity and reliability of transit systems. According to industry reports, the CBTC market is projected to grow at a rate of 8.1% annually, driven by urbanization trends and the need for more efficient public transport systems.

• This technological evolution also encompasses not only the integration of advanced automated train operations (ATO) but also the deployment of features such as automatic train protection (ATP) and automatic train supervision (ATS). Effective CBTC implementations can minimize the risks associated with human error, which has historically been a critical factor in railway accidents. For example, in June 2024, Alstom successfully launched an advanced CBTC solution for a high-density metro corridor, demonstrating improvements in service reliability and energy efficiency.

• 4-2. Integration of AI, data analytics and predictive maintenance

• The integration of artificial intelligence (AI) and data analytics into railway operations is transforming predictive maintenance capabilities. Modern railway systems generate an unprecedented amount of data; harnessing this information allows operators to make informed decisions that optimize performance and reduce downtime. AI algorithms can analyze historical data to identify patterns and predict failures, heralding a proactive approach to maintenance rather than the traditional reactive measures.

• For instance, predictive maintenance systems can analyze sensor data from trains and infrastructure to forecast potential equipment failures well before they occur. This transition enables rail operators to perform maintenance activities only when necessary, thereby reducing operational costs and extending the lifespan of critical assets. A report from 2025 noted that organizations employing predictive analytics in their maintenance programs saw maintenance costs decrease by approximately 25% while significantly improving equipment availability.

• Moreover, the convergence of AI and IoT will enhance real-time traffic management and operational strategies, allowing for optimized scheduling and resource allocation. The European Union's push for the installation of AI-based systems in national rail networks underscores the growing recognition of these technologies' potential to improve safety and efficiency. As railway systems adopt these innovations, they are not just enhancing operational efficiency but also contributing to broader environmental sustainability goals by minimizing energy consumption and emissions.

• 4-3. Wireless solutions, IoT, and onboard control advancements

• The evolution of wireless communication technologies is facilitating a paradigm shift in train control systems. Wireless solutions enable seamless data transmission between trains and control centers, significantly enhancing operational flexibility and safety. As railway operators look towards digitalization, the implementation of Internet of Things (IoT) solutions within rail systems has become increasingly ubiquitous, connecting fleets and infrastructure in ways previously unimagined.

• For example, the deployment of IoT sensors in trains allows for continuous monitoring of mechanical performance and environmental conditions. This real-time data not only informs maintenance schedules but also enhances safety by providing insights into track conditions and potential hazards. Onboard control systems equipped with advanced wireless communication technologies can respond dynamically to these inputs, adjusting the train's operations automatically based on the real-time status.

• A noteworthy instance of this innovation is the recent deployment of LTE-R (Long Term Evolution for Railways) systems, which has been implemented across several urban metro lines worldwide. These systems improve communication reliability and speed, allowing for faster emergency response times and enhanced situational awareness among train operators. Projects involving this technology, such as those launched in South Korea and Germany, underscore the global movement towards integrated and intelligent rail systems.

• As wireless technologies continue to advance, the landscape of rail transportation will undergo further transformations, paving the way for not only improved safety and efficiency but also a more connected and responsive approach to public transport solutions.

5. EU ERTMS Level 2 – Deployment Plans and Operational Performance

• The European railway network, characterized by its intricate system of signals and controls, is in the midst of a transformative era punctuated by the deployment of the European Rail Traffic Management System (ERTMS), specifically its Level 2 iteration. This modern signalling system stands not only as a technological advancement but also as a linchpin for the future of rail transport across Europe. As governments and transport authorities push towards modernization, the capabilities of ERTMS Level 2 become increasingly paramount in enhancing safety, capacity, and the overall efficiency of rail operations, paving the way for seamless cross-border travel and integrated transport systems in a digital age.

• With the railway sector traditionally seen as slow to adapt, the necessity for innovative signalling technologies is critical. The need for a unified signalling system such as the ETCS Level 2—designed to replace the existing plethora of national systems—cannot be overstated. By facilitating real-time data communication between trains and tracks, this system aims to significantly reduce delays, improve service reliability, and ultimately attract more passengers to rail transport, making it a viable alternative to road and air travel. The intersection of technological innovation, regulatory framework, and operational performance is hence at the forefront of current discussions in the realm of European railways.

• 5-1. Functional overview of ETCS Level 2 capabilities

• The European Train Control System (ETCS) Level 2 exemplifies a revolutionary step in railway signalling, employing continuous communication between the train and the infrastructure to ensure safety and efficiency. Unlike its predecessor, Level 1, which relies on trackside signals, Level 2 utilizes a radio-based system that transmits vital information directly to trains. This shift allows for greater flexibility in train scheduling and movement, permitting closer following distances and ultimately increasing line capacity. The integration of satellite positioning systems into ETCS has further enhanced its accuracy, enabling precise train localization and the automatic adjustment of speeds based on real-time data.

• One of the defining features of ETCS Level 2 is its ability to facilitate a moving block system, eliminating the need for fixed signals. By allowing trains to run closer together without compromising safety, this approach significantly enhances network efficiency. Moreover, ETCS Level 2 is instrumental in enabling European interoperability, critical for cross-border train operations. Trains equipped with this system can traverse multiple national networks without the need for changes in signalling protocols, thus streamlining operations while minimizing delays.

• As rail transportation seeks to emerge as a more sustainable travel option, the operational capabilities provided by ETCS Level 2 also align closely with EU environmental goals; optimized train operations result in reduced energy consumption and lower carbon emissions. With ongoing advancements in technology, such as integrating IoT and machine learning analytics for predictive maintenance, the potential for continued improvement in both operational metrics and safety outcomes becomes strikingly evident.

• 5-2. EU member-state rollout schedules, line-kilometre targets and procurement timelines

• The rollout of ERTMS Level 2 across European Union member states has been marked by ambitious targets and timelines, driven by regulatory frameworks and funding initiatives from the European Union. Current estimates indicate that over 25, 000 kilometers of track will be equipped with ERTMS Level 2 by the end of 2035, providing a substantial network backbone for the operation of modern, integrated rail services.

• Specific country commitments illustrate varying levels of progress and strategy. For instance, countries like Germany and France have established comprehensive plans to modernize their rail networks by prioritizing high-traffic corridors, with Germany aiming to complete ERTMS installations on critical lines by 2030. Meanwhile, Italy, with a different approach, has focused on rolling out ERTMS in tandem with the electrification of their railway lines, demonstrating how these projects can synergistically enhance rail operations. Likewise, Spain has emerged as a forerunner in ERTMS adoption, achieving over 1, 500 kilometers equipped by 2025, setting an example for other nations.

• Procurement timelines largely depend on government initiatives to secure funding and contracts with technology providers. EU funding programs have earmarked over €30 billion for the development and deployment of ERTMS, aimed at supporting member states in their implementation efforts. However, reports indicate that delays in the procurement processes and infrastructure investment can hinder achieving the desired rollout targets. A comprehensive coordination effort at the European level, alongside consistent engagement with industry stakeholders, is essential for timely project delivery and overcoming bureaucratic challenges.

• 5-3. Reported performance metrics and case study summaries

• Tracking the performance of ERTMS Level 2 implementation across Europe has unveiled a wealth of insights and outcomes that highlight both the potential and the challenges of this significant infrastructure investment. Initial rollout phases in various countries have shown promising improvements in safety and efficiency metrics. For instance, in Spain, operational data revealed that train punctuality increased by nearly 20% following the installation of ERTMS Level 2, significantly enhancing user satisfaction and service reliability.

• Moreover, case studies from Denmark's deployment of ERTMS Level 2 indicate that train delays decreased by an average of 15%. Economic analyses suggest that these improvements translate into substantial cost savings regarding operational expenditures, making the case for expanding the ERTMS rollout compelling. A noteworthy case study involves the integration of ETCS Level 2 in the UK on the East Coast Main Line, where rail operators reported enhanced capacity and significant reductions in journey times, ultimately improving the service's attractiveness.

• Despite these positive early indicators, challenges persist that must be addressed to ensure the comprehensive success of ERTMS Level 2. Integration issues with existing infrastructure, variations in national adoption phases, and the requirement for extensive training programs for personnel can introduce complexities that may impede progress. Continuous monitoring and evaluation of performance against established metrics will remain critical in shaping future ERTMS strategies, ensuring that the European railway network evolves to meet the demands of 21st-century transportation.

6. Regional Case Studies and Comparative Insights

• The ongoing evolution of railway signalling systems presents a myriad of opportunities and challenges across different regions. As nations around the globe invest heavily in modernising their railway networks, the effectiveness of these systems can vary significantly based on local contexts, technological advancements, and policy frameworks. The significance of identifying successful case studies and comparative analyses cannot be overstated; they provide crucial insights into best practices, technological innovation, and potential pitfalls that can inform future strategies. This report section delves into key regional case studies, focusing on South Korea's KTCS-2 initiative, manufacturer perspectives highlighting advanced diagnostic technologies, and comparative benchmarks against the EU's ERTMS and other APAC implementations.

• 6-1. South Korea’s KTCS-2 and domestic ATP localisation

• In recent years, South Korea has emerged as a front-runner in the development of domestic railway signalling systems, particularly through its pioneering efforts with the Korean Train Control System Level 2 (KTCS-2). Initiated in 2014, this project aimed to develop a homegrown train control system that would reduce dependence on foreign technologies, particularly those from European counterparts. KTCS-2 represents not merely an advancement in technology but a critical leap towards achieving full autonomy in rail operations. By 2025, KTCS-2 is projected to be installed on major high-speed rail lines, highlighting its importance in promoting safety and efficiency in train operations. The construction and operationalization of this system have illustrated a significant shift in South Korea's approach to railway technology, where local research and development have led to robust knowledge transfer and capacity building in the industry.

• Through its implementation, KTCS-2 has demonstrated tangible economic benefits. For example, it is anticipated to save approximately 1.21 trillion KRW by reducing reliance on foreign signalling systems. Furthermore, operational metrics indicate that the new system enables a reduction in the inter-train gap from 10.5 km to 8.1 km, which could increase overall transport capacity by 20%. These improvements emphasize the potential for KTCS-2 to serve not only as a national technological achievement but also as a model for the international market. The interoperability with the European Train Control System (ETCS) allows South Korean technology to integrate with existing European infrastructure, making KTCS-2 an attractive option for countries seeking to modernise their rail systems.

• 6-2. Manufacturer perspectives (e.g., SR’s CBM-based self-diagnosis)

• The evolution of railway rolling stock and infrastructure has stirred manufacturers to innovate beyond traditional model frameworks. Companies such as SR (Siemens Rail) are leading the charge with their predictive maintenance and Condition-Based Maintenance (CBM) systems, harnessing technologies such as IoT and data analytics to ensure optimal performance and enhance safety measures. These systems leverage real-time data to assess the operational health of rail assets and swiftly identify maintenance needs, thus reducing downtime and increasing reliability. The implementation of CBM translates into substantial cost savings and operational efficiencies for railway operators, aligning with the increasing calls for sustainable transport systems.

• Moreover, the insights from manufacturers reveal a growing trend towards modularity in design. This aspect allows operators to customize their signalling systems to specific regional requirements, thus enhancing adaptability and reducing implementation delays. For instance, SR's self-diagnosis systems are engineered to facilitate seamless communication between train control systems and onboard diagnostics, enabling proactive rather than reactive maintenance strategies. This capability exemplifies how manufacturers are not only providing technology but are also enhancing the operational capacity of railway networks globally.

• 6-3. Benchmark against EU ERTMS and other APAC implementations

• When evaluating the efficacy of railway signalling systems worldwide, comparisons between regional implementations provide fertile ground for understanding performance differentials and areas for improvement. A prime example is the European Rail Traffic Management System (ERTMS), which is viewed as a gold standard in railway signalling due to its rigorous safety protocols and interoperability features across member states. The EU's phased approach to ERTMS implementation, focusing on incremental upgrades, serves as a model for other regions. However, it also highlights challenges, such as the varying pace of adoption and the need for harmonisation amidst diverse national regulations and technological environments.

• Evaluating ERTMS alongside South Korea’s KTCS-2 illustrates both divergence and convergence in approaches to railway signalling. Although ERTMS has been developed over several decades and involves multiple stakeholders, South Korea's rapid development of KTCS-2 showcases how strategic state-driven initiatives paired with technological innovation can yield expedited timelines and budget efficiencies. The Asian Pacific region, also witnessing growth in railway signalling technologies, tends to adopt different models, emphasising localised solutions rather than blanket policies. This provides an opportunity to glean insights into modular implementation and adaptation strategies that may benefit from ERTMS frameworks, promoting a hybrid strategy that maximises both local expertise and established international standards.

7. Conclusion

• In conclusion, the evolution of railway signalling systems is not merely a technical advancement; it is a catalyst for enhancing the safety and efficiency of global transportation networks. The deployment of ERTMS Level 2 across Europe illustrates a committed movement towards standardization, promising significant improvements in service reliability and interoperability among member states. As this report has demonstrated, the integration of advanced technologies such as CBTC, AI, and IoT is revolutionizing railway operations, signifying a shift from traditional methodologies towards more dynamic and responsive systems.

• Yet, as various regional implementations and case studies indicate, the journey towards achieving optimal signalling technologies presents various challenges that require strategic oversight and investment. The insights gained from South Korea's KTCS-2 initiative reflect the potential benefits of localized technological advancements, offering a benchmark for other nations aiming to modernize. To empower future growth, stakeholders must prioritize collaboration and knowledge-sharing across borders while navigating the complexities of infrastructure investments and regulatory frameworks.

• Ultimately, the continuous adaptation and innovation in railway signalling systems are indispensable for shaping the future of transport. Industry players and policymakers must remain vigilant and proactive, ensuring that the investment in technology aligns with the overarching goals of safety, efficiency, and environmental sustainability in the ever-evolving railway sector.

Glossary

• European Rail Traffic Management System (ERTMS): A European standard for railway signaling and control that aims to enhance interoperability and safety across national rail networks.

• Communication-Based Train Control (CBTC): An advanced train control strategy that utilizes real-time communication between trains and trackside equipment to optimize train movements and enhance safety.

• Automated Train Protection (ATP): A safety system designed to prevent trains from exceeding operational speed limits and to avoid collisions by automatically controlling train movements.

• Automatic Train Supervision (ATS): A system employed to manage train schedules and movements across rail networks, improving operational efficiency and punctuality.

• Fixed-block system: A traditional railway signaling system that divides tracks into segments (blocks) where only one train is allowed at a time to prevent collisions.

• Moving-block system: A signaling approach that allows trains to operate closer together by using real-time data to define safe distances dynamically.

• Predictive maintenance: A maintenance strategy that uses data analytics and IoT technology to predict potential equipment failures, enabling timely interventions and reducing downtime.

• Internet of Things (IoT): A network of interconnected devices that communicate and exchange data to improve operational efficiency, including the monitoring of railway systems.

• Long Term Evolution for Railways (LTE-R): A wireless communication standard specifically designed for railway applications, enhancing train-to-control center communication.

• Operational performance metrics: Quantitative measures used to assess the efficiency, safety, and reliability of railway operations, often derived from data following systems' implementations.

• Line-kilometre targets: Goals set for the installation of railway systems along specified lengths of track, often part of modernization projects, such as ERTMS deployment.

• Case studies: In-depth analyses of specific instances of railway technology implementation, highlighting successes, challenges, and best practices in different geographical contexts.

• Automated train operations (ATO): A type of train operation where the functions of driving and monitoring are automated, improving service reliability and safety.

• Data analytics: The process of analyzing data to uncover patterns and insights that can inform decision-making and operational improvements.

Source Documents

• ::::: 대아티아이 홈페이지에 오신것을 환영합니다. :::::http://www.daeati.co.kr/sub02_ert.php
• 융합기술로 창의적 선도형 연구 추진 - 토목신문http://www.cenews.co.kr/news/articleView.html?idxno=5896
• 프랑스가 점령 했던 국내 철도…열차 이어 제어시스템도 국산화 | 서울경제https://www.sedaily.com/NewsView/2GV6IEEEVU/GB04
• 철도 신호시스템 첫 국산화…현대로템 '기술 자립' 가속 | 서울경제https://www.sedaily.com/NewsView/2GU9VF5M8V/GD06
• 통신 기반 열차 제어 시장 보고서, 2025-2034https://www.gminsights.com/ko/industry-analysis/communication-based-train-control-market
• 무선통신기반 차상제어장치의 전동차 시험 분석https://www.kais99.org/jkais/journal/v10n5/05/40xy/40xy.pdf
• 철도 신호 시스템 시장 규모, 점유율, 산업 동향, 2032년 예측 | WiseGuyReportshttps://www.wiseguyreports.com/ko/reports/railway-signaling-system-market
• ≪국토매일≫ 이재호 박사 '철도 신호통신의 현재와 미래' 동향 발표http://www.pmnews.co.kr/72970