Wireless Train-to-Ground Connectivity Link Demonstrated with 11.3 Gbps Throughput

ELVA’s manufacturing partner in Russia (DOK Ltd) has reported a successful test of the PPC-10G train-to-ground communication system on St. Petersburg to Helsinki railway line at a measured section between the Solnechnoye and Zelenogorsk stations. The PPC-10G 70/80 GHz wireless radios were successfully tested for train-to-ground connectivity under real railway conditions on a high-speed railway line. The max aggregated throughput at two wireless channels from the head and back of the specialized communications testing carriage reached 11.3 Gbps.

This train-to-ground communication system is designed to solve the problem of providing high-speed trains with a broadband Internet connection on straight sections of the railway. In the experiments, the test track section of 6.3 km was included three passes at a distance of 2,300, 1,300, and 2,700 m between base stations. The base stations were equipped with compact 30 cm diameter antennas and were located on contact wire supports at a height of about 5 m from the railhead. 

For minimizing the cost of the project, PPC-10G base stations could be deployed at a 2 km distance from each other or even farther. Such distance is probably the longest in the industry consider various publicly available reports. The other factor for lowering project cost is the PPC-10G base station's ability for installation at existed contact wire supports (masts) along the tracks with minimum efforts and using cheap mounting sets.

The results of the train-to-ground communication tests held in the year 2020 on the St.Peterburg - Helsinki railway line were preceded by tests in the year 2019 near Moscow. At those tests, it was shown a possibility for 10 Gbps connection to a moving train from the contact wire supports at real railway conditions using 70/80 GHz E-band equipment. The distances between base stations at Moscow tests were 370, 500, and 600 m. 

For testing the connection on the move, Russian Railways has provided a communication laboratory carriage with the locomotive. On the roof of the laboratory carriage in both directions, forward and in the opposite direction, sets of PPC-10G radios with small horn antennas were installed. A series of passes were carried out along the test section of the railway in both directions and with a change of the track (passes at the first and second main tracks).  

The following test results were confirmed in the report signed by the group of top Russian Railway officials:

  • A stable data exchange rate from any base station was protocoled at 5650 Mbps, while the total data transfer rate was 11300 Mbps (taking into account communication in both directions as 2x 5650 Mbps).
  • The minimum data transfer rate for all tests was no worse than 2800 Mbps per channel (the total bandwidth to train was no worse than 5650 Mbps consider connection into both directions).
  • The maximum distance between base stations to provide any train-to-ground connection was 4 km, with a confirmed recommended distance between base stations about 2 km.
  • The network architecture works stably on straight sections of the track in conditions of line of sight between base stations and train radios. An essential condition for the stability of the connection is the straight-line profile of the track without curves, significant differences in heights (descents and ascents), which is generally typical for the structure of high-speed railways.

Click here to read the report.