Belden Hirschmann industrial networks provide a highly reliable, low-latency, and environmentally adaptable communication foundation for rail transit signaling systems, supporting the evolution of moving block systems such as CBTC and TACS. Real-time performance and security are ensured through hardware redundancy, fast switching protocols (such as MRP/PRP/HSR), time synchronization (PTP/TSN), and multi-layer logical isolation (VLAN/ACL). They possess environmental tolerance capabilities including wide temperature range, dust and corrosion resistance, and electromagnetic compatibility, supporting modular expansion, remote diagnostics, and traceable auditing. Deployed in over 120 subway projects, they provide a stable and scalable "nervous system" for the signaling subsystem, ensuring operational safety and efficiency.
In the network deployment of signaling systems in China's rail transit industry, solutions consistently face multiple challenges related to "safety and efficiency":
Harsh physical and electromagnetic environments: The installation environment for rail transit is complex and variable. Industrial networks can withstand continuous vibration, dust, humidity, and wide temperature variations between indoor and outdoor environments, ensuring clear and stable signals even under strong electromagnetic interference.
Reliability and Availability: Through redundant design at the physical and network layers, single points of failure are eliminated from the hardware to the redundant protocol level, providing near-uninterrupted communication assurance for the signaling system.
Real-time Communication Capability: For critical tasks such as Automatic Train Protection (ATPB), latency must be predictable to the millisecond or even microsecond level. The network should achieve low latency to ensure control commands are delivered within the specified time window.
Unified and Converged Communication Platform: Modern communication-based CBTC (Computer-Assisted Train Control) signaling systems have created a demand for a unified network. The network should ensure secure isolation while carrying business data transmission between different subsystems, guaranteeing the availability and accessibility of core data, simplifying the architecture while maintaining efficiency.
Belden Hirschmann Industrial Network and Signaling System Adaptation
Comprehensive Environmental Tolerance Verification
Capable of operating in a wide temperature range (e.g., -40℃ to +70℃), with a coating design for moisture and corrosion resistance.
Chemical and Dust Protection: High protection rating of IP65/67 for outdoor use, preventing dust intrusion and corrosion from harmful gases.
Long-term reliability: Based on a high MTBF design, the average mean time between failures (MTBF) exceeds 25 years, with some modules exceeding 100 years.
Electrical stability: Features high-level electromagnetic compatibility and electrical isolation design, ensuring signal integrity under interference.
High-level reliability and availability:
On the hardware side, Belden's industrial-grade products feature redundant power supplies and redundant module designs.
On the software side, Belden provides various redundancy technologies to ensure the reliability of the entire network, such as the IEC 62439 standard Industrial Ring Redundancy Protocol (MRP) and dual-redundant ring network coupling technology, achieving network redundancy switching within 50ms.
Supports modular hot-swappable modules, remote diagnostics, and predictive maintenance, significantly reducing mean time to repair (MTBF).
Low-latency，low-jitter real-time data transmission:
Conventional solutions utilize time synchronization protocols such as SNTP, NTP, and IEEE 1588 PTP to provide millisecond, microsecond, or even nanosecond-level deterministic communication guarantees for Ethernet.
Industrial-grade network products supporting TSN technology ensure the delivery of train control commands and movement authorizations within strict time limits.
Seamless switching redundant communication protocols such as PRP/HSR provide uninterrupted communication channels for onboard-trackside communication and interlocking systems.
Logically layered, defense-in-depth dedicated communication architecture:
Covers various Layer 2 virtual LANs, including standard VLANs, port-based VLANs, protocol-based VLANs, voice VLANs, MAC/IP subnet-based VLANs, and Private VLANs, meeting the logical isolation requirements of different services within the line area.
Coverage of Layer 3 routing protocols such as RIP v1/v2, OSPF v2, static routing, and PIM-DM/SM/SSM provides core support for reliable and efficient communication across regions and levels.
The combined use of ACL technologies, including Basic ACL, MAC-based ACL, IP-based ACL, Time-based ACL, and VLAN-based ACL, constructs a refined and dynamic three-dimensional security and traffic control system for the signaling system from multiple dimensions such as time, space (VLAN), direction, and bandwidth.
Relying on a defense-in-depth system comprised of firmware trusted verification, intelligent access control, and dynamic policy management, the integrity and reliability of the system are comprehensively guaranteed.
In the continuous upgrading and evolution of rail transit signaling systems, Belden Hirschmann's professional industrial network solutions have become a reliable cornerstone for the industry's digital construction. Our solutions have been applied to over 120 subway signaling system projects nationwide; these extensive practices have forged our profound understanding. Moving forward relentlessly, Belden Hirschmann continues to dedicate itself to building a reliable nervous system for the rail transit industry through innovative connectivity technologies, continuously driving improvements in driving safety and operational efficiency, and ensuring the smooth pulse of urban transportation.
Post time: Mar-20-2026