After more than 20 years of the GSM-R success story, it is now time for the next generation of rail...
UC #1.3: Rail Critical Services
The Rail Critical Services at the 5G-VICTORI facility in Berlin comprise five representative type of services. To implement these services the biggest train station in Europe will be used, the Berlin Central station, which is a challenging operational environment to accommodate the 5G-VICToRI HW and SW 5G solutions to support the UC.
Four of them are related to communications between the Office and onboard a train, and the last one is offered as a wayside service. These services are:
- Onboard services:
- Rail signaling.
- CCTV monitoring.
- Telephony (Cab Voice and Emergency Calls).
- Sensor data.
- Wayside services:
- Wayside Point-machine Object controller signaling.
These services were in the past served by purposely deployed legacy wired and wireless technologies. The advent of 5G and the availability of 5G equipment and state-of-the-art wireless and optical technologies, has led to the re-definition of the UCs and the associated services. To date, 5G is being rolled out on railway stations worldwide. This is one of the motivations to consider such venue to assess the performance of the services being supported by this technology.
5G-VICTORI Berlin Facility
The 5G-VICTORI Berlin facility extends the 5G connectivity towards the Berlin Central Station in support of three UCs. These UCs impose different service requirements that map to the 3GPP defined service classes: eMBB, uRLLC and mMTC. The design of the Berlin facility network covers three additional sites supporting 5G and Wi-Fi connectivity, including a 5G-capable testfield that is being used for testing FRMCS features.
Figure 1 represents the different parts of the infrastructure within the Berlin Central station that will be involved in UC #1.3. The Berlin Equipment Room (aka. Berlin Office), can host all management components of the Berlin facility – so it can be done at the Fraunhofer FOKUS site for testing between the two sites. The Equipment Room hosts the edge compute/data centre, together with the 5G NR Baseband Unit (BBU), and switching components. At the Platform, the 5G NR equipment will be installed for provisioning 5G connectivity to the train.
The wayside equipment will involve the use of a point machine and the train hosts the onboard computing and storage plus the access network equipment of various technologies.
Rail Signalling, Critical Telephony and Sensor Data Transmission services will be provided as part of the Rail Critical Services taking place at the Berlin Central Station between the Berlin Office and onboard the train.
Rail Signalling is emulated using a traffic generator, which can be configured to send traffic in both directions. Rail Critical Telephony and Sensor Data transmission are performed live using a set of on-train, mobile and fixed terminals running rail applications (voice, emergency call, data app and sensor app), which are communicating with each other through rail critical, performance or business data sessions.
CCTV is streamed from the train to the office, using a CCTV network camera. The camera is mounted in front of the train and images are monitored from the Berlin office using a web browser that accesses the camera. The camera is not fitted with an SD memory card, as no recordings are planned.
For the Point-machine object controller signalling UC, the Rail Signalling traffic is extracted from a productive interlocking system via the usage of a network Test Access Point (TAP) – Siemens Data Capture Unit (DCU) –. The purpose with this UC is to ensure, that specific timing KPIs of the communication can be met as well as different types of traffic can happen at the same time without influencing the signalling traffic.
Rail Signaling over 5G
The air-interface for radio communication in general is the scarce resource in our society. Many kinds of vertical service traditionally...