Broadband  |  2024-02-19

New FRMCS Antenna will Revolutionise Critical Communications for Trains

Source: The Critical Communications Review | Gert Jan Wolf editor

A new purpose-built FRMCS antenna to be unveiled by Ericsson at Mobile World Congress is set to change how the railway industry communicates, and getting onboard early will be key to maximizing the benefits and efficiencies for rail operators.

A new purpose-built FRMCS antenna to be unveiled by Ericsson at Mobile World Congress is set to change how the railway industry communicates, and getting onboard early will be key to maximizing the benefits and efficiencies for rail operators. By integrating years of expertise in critical communications with industry-leading capabilities in 5G, Ericsson's novel antenna empowers operators with an unprecedented array of opportunities.

Railway operators encounter several challenges that can be converted into opportunities through the implementation of 5G technology. These challenges include optimizing inter-site distances to support both Railway Mobile Radio (RMR) bands, introducing new broadband applications that demand higher throughput, and overcoming the impending obsolescence of GSM-R in the most cost-effective manner.

Future Railway Mobile Communications System (FRMCS), which is replacing GSM-R, is built on 5G. As a result, the industry requires a new form of antenna that maximizes the advantages of 5G radio technologies while maintaining GSM-R support during the migration period. The FRMCS is expected to span over two hundred thousand kilometers of railway.

By integrating years of expertise in critical communications with industry-leading capabilities in 5G, Ericsson's novel antenna empowers operators with an unprecedented array of opportunities. In doing so, it fulfills the demands of the railway sector and fulfills the potential of 5G.

Facilitating the transition from GSM-R to 5G-based FRMCS

One of the challenges associated with substituting a system such as GSM-R is that, notwithstanding its evident drawbacks, it has operated so efficiently for over two decades. Throughout that time, the standard has enabled mission-critical communications necessary for the operation of rail networks; these communications will be among the initial applications that FRMCS addresses.

One of the primary objectives of FRMCS is to ensure a high level of dependability. Given the daily movement of hundreds of thousands of passengers and tons of freight across international and continental rail routes, FRMCS is designed to be as robust as possible in order to prevent network outages. To achieve this, it employs two distinct rail mobile radio (RMR) bands.

In general, GSM-R systems were deployed with tunnel coverage provided by directional antennas or leaky cables (cables with gaps or slots in their outer conductors that permit radio signals to pass through or out of the cable along its entire length) and utilizing dedicated base station masts situated in proximity to railway tracks. By strategically placing the base stations along the railway lines, a high level of redundancy, availability, and dependability is established.

However, notwithstanding its evident advantages, GSM-R will never be able to accommodate the capacity demands of autonomous train operations and video surveillance.

The proliferation and variety of use cases and services enabled by 5G and FRMCS will expand, while the transfer of enormous quantities of data will become feasible, paving the way for driverless trains. The enhanced communication capabilities offered by FRMCS enable an increase in train density, thereby permitting a greater number of locomotives and carriages to operate continuously on the rail network at any given moment.

Future high-speed connectivity

The newly developed trackside antenna is wind load optimized, lightweight, and simple to deploy. It is constructed with sustainability in mind and is capable of withstanding the most severe weather conditions.

The implementation of FRMCS will necessitate an increase in the quantity of antennas required by rail operators; therefore, they have a significant interest in ensuring that such installations are relatively straightforward and expeditious. The lightweight unit of Ericsson's new antenna, which is constructed with a 100 percent recyclable radome, is less than 20 kilograms; an engineer is capable of transporting and installing a single unit at the construction site.

In light of the frequency constraint, rail operators are actively striving to optimize the utilization of the available spectrum and maximize efficiency. In pursuit of this objective, the development of the new antenna has been undertaken.

With an integrated calibration port that enables beamforming and four cross-polarized columns for effective spectrum utilization, the antenna is optimized for the new 1900-1910 MHz band utilized by FRMCS TDD. The newly implemented antenna is capable of electrical downtilt and can be remotely adjusted by incorporating a control unit or adjusted locally.

Ericsson is not only implementing this antenna modification but also developing a new FRMCS radio that is designed to be compatible with it. The FRMCS radio under consideration is designed to accommodate 8T8R (eight transmitters and eight receivers) operating on frequency band n101, which is designated for rail use between 1900 and 1910 MHz. By means of phase synchronization, horizontal beamforming can be achieved by the radio and antenna. As a consequence, the beam will be capable of trailing the train around a curve, which will significantly increase throughput. In addition, further antenna varieties that possess both FRMCS and GSM-R functionalities are in the works, enabling railway operators to utilize a single antenna for both features. This can be advantageous when preparing for FRMCS and upgrading existing sites to maintain GSM-R capability.Moreover, the number of terminals and frequency that the antenna supports are both synchronized with the new radio unit.

How 5G railway communications will be transformed by 5G

A new FRMCS infrastructure can be deployed on GSM-R sites already owned by the majority of rail operators; the advantages of doing so will become evident in an instant. Due to the reduced size of the new antennas, the necessary apparatus will require less space, resulting in a lighter and more compact site.

Furthermore, the implementation of artificial intelligence (AI), machine learning (ML), and the Internet of Things (IoT) in the upkeep of rolling stock and infrastructure is an intriguing possibility expanded by 5G. The implementation of 5G-enabled sensors within the rail network could facilitate communication between the various components and maintenance services, enabling the detection of impending component failures and subsequent replacement, as well as the reporting of impacts or damage that could potentially compromise safety or performance.

Moreover, 5G video links enable remote control of trains and inspection of infrastructure, thereby obviating the necessity for human involvements such as drivers per train and site visits. This results in labor cost reductions, enhanced safety measures, and more sustainable maintenance operations.