With metro passengers, powered by their smartphones, demanding greater connectivity while they use trains and the station, network operators are trying to keep up by deploying the latest technologies: automated train operation via CBTC (Communication Based Train Control), public Wi-Fi networks, and on-board CCTV are all now transforming metro journeys in cities around the world.
Individual radio networks are typically deployed to support these applications. However, this “silo” approach to supporting connectivity, while effective in the short-term, is ultimately costly and extremely inefficient.
The French government is attempting to address the issue through its Investments for the Future – National Fund for Digital Society program. This provides financial support for R&D projects to investigate an optimal solution to the connectivity problem across industries, and for rail networks specifically it is the focus of the SySTUF (System Transport Urban Future) project, which is led by Nokia with support from seven industry partners.
SySTUF has tested 4G LTE mobile broadband as the foundation of a single integrated radio network, which supports individual applications. In contrast to the silo approach, LTE is capable of carrying voice and data for train control, onboard video surveillance, and passenger information simultaneously on a single IP radio network. It also offers high-speeds, enhanced security, large capacity, and low latency.
Initially the trials took place in Nokia’s lab, which helped to optimize the LTE network parameters, including with trains operating at 80km/h, before live trials began on Paris metro Line 14 in December 2015. They concluded at the end of May 2016.
Watch the LTE Paris Line 14 trial in action here:
The Line 14 live trial encompassed the installation of a standard LTE network operating at 2600MHz TDD and covering the line’s two tunnels as well as three stations and the depot. By testing its capability to support both mission-critical and less vital services, the trial looked at whether the architecture could become the foundation for the next-generation of ground-to-train communications network. Tests were performed in real operating conditions with both normal and extreme data traffic conditions where the radio network was purposely saturated to check its performance.
The results exceeded expectations. SySTUF showed that LTE can offer service prioritization and excellent service level quality. For example, the most critical applications such as CBTC and clock synchronization were able to operate with no packet loss and lower latencies than conventional WiFi technologies, even in metro tunnels and when operating in proximity with other trains. Engineers also found that when designing a network it is preferable to avoid the cell edge effect when non-automated trains stop in the station as it ensures maximum performance of a platform TV application, or CCTV downlink.
SySTUF therefore makes a strong case to adopt LTE as the foundation of a future all-encompassing network architecture. The results show that it will help operators to continue to deploy the latest technologies in a more timely and efficient manner, and desert their current silo approach for the benefit of their passengers and operations.
See live demo at InnoTrans 2016: 20-23 September in Berlin, hall 4.1 stand 216.
Download new white paper: Paris metro LTE trial – the SYSTUF project and its results
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