How LTE-M enhanced Mexico City's metro experience

Mexico City

Before the city wakes, metro trains tunnel through the darkness, their lights streaming down the tracks like luminous rivers. As the trains near Pantitlán Station, rails branch out in all directions, using a transport network built on signaling and digital technologies.

Such technologies are in large part responsible for the constantly improving efficiency, speed, and service quality of modern rail systems. Intelligent transformation has become a game-changing solution.

Take rail operations, for example. As the number of passengers increases, more devices have been deployed, resulting in higher operational costs and security risks. In complex urban rail settings, the traditional Wi-Fi train-to-ground wireless solution has several limitations:

• The Communication-Based Train Control (CBTC) system is vulnerable to interference, which compromises its reliability and stability.
• Limited signal coverage requires a high-quality communications network.
• Complex networking, limited coverage, and countless inter-station devices lead to costly maintenance.

To make matters worse, the system had become outdated. Mexico City currently has 12 metro lines; the fragmented approach to constructing these lines separated management from operations. Metro Line 12 used Automatic Train Control (ATC), a railway signaling and control technology that enables automatic operation of trains. The other 11 subway lines relied on older signaling systems and had limited transport capacity.

In addition, the metro detection system, used to determine the exact location of the trains at any given moment, was inadequate, resulting in frequent slowdowns. To prepare for a digital future, the Mexico City Metro had to plan for spectrum allocation and a transition to a broadband LTE network that would lead to more secure, more efficient operations.

Drawing on its own engineering expertise and industry knowledge, Mexico City Metro partnered with Huawei to deploy the Smart Urban Rail LTE-M (Metro).

LTE-M is a wireless, train-to-ground communications solution for urban rail transportation. It provides one network to carry both mission-critical services such as CBTC, which ensures safe train movement, and non-mission-critical services, such as the onboard Passenger Information System (PIS) that displays train schedules and the Closed-Circuit Television (CCTV) security system. The system integrates previously separate systems such as rolling stock (trains and mechanical components) with the signaling that controls trains’ movements and the data exchange between trains and controls centers. This integration creates one unified, efficient network.

LTE-M also guarantees stable communications in challenging environments, such as underground tunnels and remote tracks. It improves service assurance in various domains:

• Track security. Mexico City Metro uses LTE-M for video monitoring in key sections of track. This promptly identifies anomalies, safeguarding operations and establishing a robust security perimeter.
• Zero service interruptions for more convenient travel. The signaling system has transitioned to the CBTC system to eliminate interference from public frequency bands. This upgrade showcases the strong resilience and reliability of LTE-M, ensuring stable signaling systems, on-time trains, and a smoother, more convenient travel experience for passengers.
• Automatic train departure for increased efficiency. The CBTC uses LTE-M to elevate the grade of automation, shorten train departure interval, and boost operational efficiency by 35%. This decreases passenger stress and makes travel more pleasant.

This marks the first time that LTE technology is being used in Mexico City Metro for train-to-ground communications services, showcasing technological progress and a strong dedication to passenger well-being and service quality. Mexico City's mayor has said that the "Metro Line 1 has been completely renovated, with only the entrance and exit points remaining unchanged. All other facilities are now new, promising a fresh and more comfortable metro ride for our residents."

In addition, the Director of the Mexico City Metro noted that the revamped Metro Line 1 incorporates superior materials and advanced technologies, and adheres to strict rail transit construction standards. This positions Mexico City Metro Line 1 as one of the premier metro lines in the world.

Mexico City Metro's practices have set new benchmarks for smart urban rail in the modern era. Invisible intelligence is revolutionizing daily operations in Mexico City, from the subtle glow in metro tunnels 27 meters underground to the vehicle lights on elevated viaducts.

Thanks to real-time connectivity, smart enablement replaces device stacking, significantly improving transport capacity. As a train travels at 80 km/h, it transports not only 1,500 commuters, but the digital and intelligent evolution of metro systems. Huawei's leading technologies revitalize legacy infrastructure: five decades after its inception, the track system originally built in 1969 now embodies 21st-century smart urban rail.