The entire system consists of multiple subsystems such as access control systems, ticketing systems, visual real-time tracking dashboards (of trains, depots, and stations), emergency communication systems, anti-theft alarms, and perimeter alarm systems. Together, they make the metro station a safe place for both passengers and staff.

Every part of this integrated security system is built with technologies that are continuously evolving and improving. For example, the bearer network needs to provide high bandwidth across long distances, support service upgrades at any time, offer high availability, and have total control over processes and nodes.

These requirements bring many challenges for the reliability and operation of bearer networks, which may increase the risk of information leakage of access devices, as well as the responsibility to manage new and ongoing maintenance issues.

Another issue is bandwidth. Displays and other HD terminals are densely distributed. Turnstiles, electronic signs, and emergency broadcast devices are operating all day, producing massive amounts of data. Therefore, the need to provide higher bandwidth while operating more efficiently is hard to achieve.

Maintaining network quality in traditional networks is not easy, with several environmental factors causing signal degradation, and ultimately a low return on investment. For example, the average distance between adjacent metro stations is around 2km, yet a wired network needs to be converged every 100m, which may cause signal attenuation. Also, steel trains may cause electromagnetic interference and increase the distortion of trackside images. In addition, more investment is required for the construction of equipment rooms, which occupy valuable space and reduce the overall operational efficiency of the metro system.

Installing an all-optical network will be beneficial to urban rail networks.

The solution to these problems is to replace traditional networks with passive all-optical networks. Several metro systems in China have chosen an all-optical network solution to handle the communications network across their metro stations, tracks, and depots.

An all-optical network that meets the requirement of the European Telecommunications Standards Institute (ETSI) definition of a Fifth Generation Fixed Network features 10G+ bandwidth, microsecond-level deterministic latency, and full-fiber connections. The innovative all-optical network enables visualised operations and maintenance in metro environments for more efficient management and a more secure transportation system for customers.

Huawei offers an all-optical network solution for transportation sites and systems, replacing the traditional network convergence layer with passive optical splitters and realisng one-hop connections between the data center and terminals.

The transmission distance of all-optical industry networks is up to 40km, solving the issue of short transmission distance in traditional networks and reducing the network planning complexity in metro environments. All-optical networks are based on a point-to-multipoint architecture and can provide a large split ratio up to 1:128, which are well suited for the backhaul of massive information points. Even one aggregation OLT can handle thousands of HD terminals.

The large capacity of Huawei's all-optical network solution achieves information flow in complex metro networks and is used to build full-series IoT networks including displays, turnstiles, electronic signs, and emergency broadcast devices, providing an information highway for communications networks in metro stations.

Most metro systems use the 10G PON technology to deploy networks which can be upgraded to 50G PON without re-cabling and facilitate the deployment of new HD terminal backhaul points or smart systems.

The all-optical solution uses fibers for intra-station communication. The link from the aggregation layer to Optical Network Unit (ONU)  consists of passive optical splitters and fibers that are immune to electromagnetic interference, reducing the fault rate and ensuring full-time, secure, and stable network operation.

Huawei's Network Management System supports plug-and-play ONUs, automatic service provisioning, visible batch configuration, and smart operation and maintenance (O&M) in a user-friendly interface. Technicians can deploy devices in minutes instead of hours. And if a fault occurs, maintenance personnel can quickly locate the fault and simply replace the faulty device.

There is a strong market for these smart urban rail applications. In China alone, the market space will increase from $US 4.16bn in 2020 to $US 12.42bn in 2026, according to China Urban Rail Transit Association.

In this new era of smart cities and digital transformation, smart metros equipped with new all-optical network will become an important building block in a city's modernisation efforts.

For more information about Huawei Optical Terminal, please click here.