To ensure passenger safety and comfort, and enhance the attractiveness of their transport offer, operators need to collect and process increasingly large flows of data in real time, for video surveillance, maintenance, VoIP, passenger information, and so on.
The smooth running of these services is ensured by high-speed, reliable and continuous communication between a moving train and the ground.
The latest ACKSYS products combining WiFi 802.11ax (WiFi 6) and 5G cellular connectivity enable seamless communication with uninterrupted data flow between on-board equipment and the ground.
THESE APPLICATIONS REQUIRE HIGH-AVAILABILITY NETWORKS.
In the case of metros and tramways, the main task is to transport video streams from onboard to the ground.
Onboard-ground communication generally uses WiFi (2.4GHz or 5GHz), with access points on the ground (AP mode) and onboard (client mode). Train to ground communications use an ultra-high-speed radio system (BBRS Broad Band Radio System) based on the latest WiFi standards, such as 802.11ax (WiFi 6).
Redundancy of the solution is ensured by 2 ACKSYS’ RailBox access points installed on board, one at the front of the train and the other at the rear, using the VRRP protocol.
The distance between each ground AP is determined by the speed of the subway, the throughput required and the level of redundancy required. For the ground infrastructure, ACKSYS offers 2 solutions:
– RailTrack (triple radio WiFi, 100-240 VAC power supply, SFP ports and 1Gbps Ethernet connectors in M12 format)
– RailBox (dual radio WiFi, 24-110 VDC or PoE power supply, 2.5Gbps Ethernet connectors in M12 format)
ACKSYS has developed a high-performance solution for train-to-ground communication: CBB (Connect Before Break) and PLH (Predictive Linear Handover).
With roaming close to 0ms and packet loss below 0.1%, data rates are very high and communication is of excellent quality. This solution requires dual-radio ACKSYS APs on board (client mode), and can work with ground APs from ACKSYS or other manufacturers. This solution has been successfully deployed on numerous subway lines.
Cellular communications are also increasingly used for the transmission of non-critical information such as video surveillance and passenger information, using private or public networks. It is also possible to aggregate flows from several mobile networks to obtain an optimal connection. ACKSYS cellular RailBox are deployed in both 4G and 5G on numerous projects requiring LTE radio systems. With these solutions, ACKSYS offers a robust and adaptable infrastructure to ensure reliable and continuous train-to-ground communication, essential for rail operators.
