Ondas Networks supports deploying a new IEEE 802.16 (dot16)-based 900 MHz network to ensure resilience for critical train control functions
The new 900 MHz network can support next-generation ATCS and provide redundancy for train control applications by hosting ITCM applications currently hosted in the 220 MHz network in addition to other existing and new IOT uses cases
In March 2023 the AAR selected IEEE 802.16t as the wireless platform for the new 900 MHz network, as codified in AREMA standards
In a 2020 agreement with the Federal Communications Commission (FCC), Class I Railroads committed to retiring the legacy 900 MHz wireless network by September 2025. For over 25 years, this legacy network has been the backbone of Automated Train Control Systems (ATCS), supporting essential signaling and critical train control functions. To ensure continued reliability and operational efficiency, the FCC allocated a new 900 MHz frequency band, the 900 “A-block”, to the Association of American Railroads (AAR). This transition aims to modernize rail communication infrastructure while maintaining uninterrupted service.
The Association of American Railroads (AAR) has collaborated with railroads, rail technology providers, and other stakeholders through IEEE-regulated processes to develop the IEEE 802.16t (dot16) industrial wireless standard. The dot16 standard meets mission-critical rail requirements and has been extensively tested and validated by organizations within the AAR, including the Wireless Communications Committee (WCC), MxV Rail, and individual railroads. As a result, 802.16t was chosen as the standard for the new 900 MHz network in March 2023 and is codified in the AREMA rail standards, ensuring a reliable and efficient future for rail operations.
The 900 MHz Transition
As railroads retire their legacy 900 MHz network, they must provide for the ATCS functionality, a critical train operating system that is hosted on the legacy 900 MHz wireless network. ATCS enables Centralized Traffic Control (CTC) which allows dispatchers to control train movements over extensive areas from a central location, setting routes, controlling switches, and managing signals to ensure smooth train flow. By using a combination of physical signals, track circuits, and communication lines, CTC relays commands from the dispatcher’s office to field equipment, preventing conflicts such as two trains occupying the same track segment simultaneously. This system optimizes traffic flow, reduces delays, and enhances overall operational efficiency, focusing on scheduling and routing rather than direct safety intervention. Historically, CTC has evolved from manual methods to more automated systems, reflecting its long-standing importance in the railroad industry.
The new 900 MHz network is likely to serve as both a primary and secondary network. In certain operating environments, Class I railroads may choose to move CTC traffic from the legacy 900 MHz network to the 220 MHz network, which currently hosts the Positive Train Control (PTC) application. While consolidating CTC and PTC on a single network has some benefits, it would result in two safety critical applications being hosted on a single network. To mitigate operating risks and avoid a single point of failure, the Class I railroads can deploy a dot16-enabled 900 MHz wireless network as a secondary option providing valuable redundancy and resiliency for railroad operations.
IEEE 802.16t (dot16) – an Open Standard
The new 900 MHz network, which the AAR agreed with the FCC to build on the new A-block spectrum, is slated to use the open standard IEEE 802.16 wireless technology. This choice is crucial for modernizing railroad communication, enhancing efficiency, and boosting safety. Dot16 offers high data capacity and robust connectivity, essential for managing data from advanced edge computing and IoT devices. This ensures real-time data transmission and analysis for applications like predictive maintenance, remote monitoring, and automated control systems, thereby improving overall efficiency and safety.
Dot16 also fosters an ecosystem of rail, enterprise IT, and IoT vendors, encouraging innovation and collaboration. Its standards-based approach enables seamless integration of diverse technologies and systems, developing smarter, data-driven train operations. Additionally, dot16 allows for a transition from legacy serial data protocols to a modern IP-based wireless network, offering greater capacity and flexibility than legacy networks. This allows railroads to adopt new use cases beyond basic train control, such as advanced analytics, real-time monitoring, and enhanced safety protocols.
General Purpose, IP-based Network
A dot16 wireless network can host a newly designed and upgraded next-generation ATCS platform providing more powerful edge computing capability combined with a higher capacity, modern IP-based network which can host additional train operating and safety systems that the legacy network was not equipped to support.
The limited bandwidth and reliability of the legacy 900 MHz network restricts the ability to transmit large volumes of data from sensors and edge devices. By transitioning to a new, high-capacity network, railroads can implement more advanced monitoring systems that provide real-time insights into the condition of tracks, trains, and other infrastructure. This upgrade will enable more proactive maintenance, reducing downtime and enhancing overall operational efficiency.
A higher capacity general purpose IP-based network, made possible by dot16 technology, supports a range of new rail applications. The enhanced capabilities of this network can enable a host of existing and new applications, including:
Advanced defect detection (e.g. thermal imaging)
Live transmission of track testing results (e.g. track geometry measurement data)
Increased support for rail integrity monitoring
Increased oversight of maintenance activities
Continuous monitoring of highway grade crossing equipment
PTC base station and wayside location backhaul (ITCM-over-802.16t radios)
Monitoring of maintenance-of-way vehicles
In addition, many railroads are making plans now to run a new 900 MHz network as both a primary and secondary network. Ondas Networks has demonstrated the ability to carry Interoperable Train Control Messaging (ITCM) protocols on a dot16 wireless network and is engaged with certain railroads now in deploying “ITCM over 900” to support primary and secondary network hosting of PTC and CTC applications in the new 900 MHz A-block. ITCM over 900 MHz is expected to be deployed by certain railroads by the end of 2024.
This level of resiliency, afforded by a multi-purpose dot-16 enabled private wireless network, is not available with the single purpose legacy rail networks in operation today.
Support from Ondas and Siemens
Ondas Networks and Siemens have been integral in facilitating the migration from the legacy 900 MHz to the planned new network hosted on the 900 MHz A-block. They have worked extensively with the AAR and critical technology groups including the Wireless Communications Committee (WCC) and MxV Rail. Further, Ondas Networks has been a leading visionary and the principal wireless IP contributor supporting the evolution of the IEEE 802.16 standard for private industrial networks. Dot16 is an open standard that allows for broad participation for the railroad technology vendor community.
Together Ondas and Siemens have developed the next-generation ATCS solution, which provides important upgrades to the legacy applications which included integrating enhanced edge computing functionality, and the capabilities of the dot16 open wireless standard. Ondas and Siemens have also designed the system to ensure backwards compatibility which will facilitate seamless migration and minimize operational risks in deploying and operating the new network. This same software-based network supports ITCM over 900 MHz and a host of additional applications.
Ondas, Siemens and other vendors and service providers are engaged in supporting the adoption of the dot16 wireless standard across the North American railroad sector, as well as driving future technology roadmaps that can benefit from the higher data capacity and flexibility of private rail wireless networks that have been upgraded with dot16 capabilities.
Conclusion
Ondas Networks is committed to supporting railroads on their path to build out the new 900 MHz network utilizing the IEEE 802.16t capability, while also moving CTC capability with the newly upgraded next-generation ATCS offered by Siemens. Railroads choosing to consolidate the CTC application on the 220 MHz PTC network should seek to reduce operating risks from a single network and legacy technology by deploying ITCM over 900 MHz to ensure redundancy. In short, train control applications should look to utilize the new 900 MHz network as both a primary and secondary, or redundant, wireless platform for train control applications, as well as for other operational and safety technologies as described above.
The transition from the legacy 900 MHz network to a new, modern 900 MHz frequency band creates significant opportunities for the rail industry. With the support of Ondas Networks and other vendors, this migration promises to be seamless, ensuring continuity in rail operations. The implementation of IEEE 802.16t technology will not only sustain existing and new train control capabilities, but also pave the way for a robust, flexible, and high-capacity IP-based wireless network. This modern infrastructure will support a range of innovative applications, enhancing safety, efficiency, and customer experience across the rail system. As the railroads adapt to these technological advancements, they position themselves for a future of continued growth and improvement.
Further, the adoption of 802.16t on 900 MHz is the first step to modernize other legacy private rail wireless networks further supporting the introduction of data-intensive, intelligent systems and infrastructure offered by the rail vendor community in support of more efficient and safe train operations. The shift to an IP-based network facilitated by dot16 helps ensure that rail communication infrastructure can meet future demands and continue to grow in capability and reliability.
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Eric Brock is Chairman and CEO of @OndasHoldings (Nasdaq: ONDS) and Ondas Networks. Ondas Networks is a developer of software-based wireless technology for large established and emerging commercial and government markets. Ondas Networks' standards-based (802.16s), multi-patented, software-defined radio FullMAX platform enables Mission-Critical IoT (MC-IoT) applications by overcoming the bandwidth limitations of today's legacy private licensed wireless networks.