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TS 22.289SA1
Mobile Communication System for Railways

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V17.0.0 (Wzip)  2019/12  17 p.
V16.1.0 (Wzip)  2019/03  17 p.

Rapporteur:  Mr. Merkel, JürgenNokia Germany

The present document provides requirements for railway communication. Railway communication is based on the set of Mission Critical specification TS 22.280, TS 22.179, TS 22.281, TS 22.282. Requirements for railway communication not fitting the scope of those specifications are provided in this TS.

full Table of Contents for  TS 22.289  Word version:   17.0.0

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1  ScopeWord-p. 5
2  References
3  Definitions, symbols and abbreviations
4  Railway communication functionality
4.1  Bulk Transfer of CCTV archives from Train to Ground
4.1.1  Description
The video surveillance system in trains consists of multiple cameras which are recording and encoding the video feeds 24/7 either into the video recorders or into internal memory of the cameras themselves. The amount of video recordings is excessive, which exceeds rather fast the physical storage capacity that is available in video recorders and/or in cameras. The regulations in different countries are ruling retention time for recordings until up to 31 days or even more. However, the recordings need to be stored in the physical storages located in the vehicles for only seven days.
4.1.2  RequirementsWord-p. 9
4.2  Bulk transfer of multimedia from ground to train
4.2.1  DescriptionUp
The offering of multimedia services to the passengers is becoming default service during long travels in airplanes and more and more, also in trains. In order to minimize the excessive consumption of network capacity between train and ground, a bulk transfer of multimedia databases from ground to train during stops at the stations and depots is optimal solution. The bulk transfer of multimedia is done when the train stops at the stations, stops and depot, ideally with minimum of one gigabit transfer speed. Hence, the multimedia content can be more versatile and updated in regular basis. The actual content is also consumed in-train network operated by the FRMCS and hence it does not give burden to the link budget between train and ground. The multimedia may contain movies, TV shows, cached webpages etc.
The bulk transfer of multimedia is facilitated by the FRMCS, which provides means for transferring the multimedia databases data between ground communication units, located at the depot, stations and/or stops alongside the predetermined route of the train. Whenever the train approaches the stations and/or stops or arrives into the depot, FRMCS facilitates the communication between the ground and mobile communication unit, if bulk transfer of multimedia transfer is requested. The ground communication unit uploads the multimedia databases from ground into the mobile communication unit in the train, where the data is stored in the train multimedia data storage. The generic procedure for the bulk transfer of multimedia between the ground and mobile communication units could be e.g as described in the following;
  • The ground communication unit is monitoring whether a transmission signal from the mobile communication unit is available and that the signal quality is sufficient for synchronization.
  • Upon successful synchronization, the mobile communication unit requests multimedia upload from the mobile communication unit and the connection between the ground communication and mobile communication unit is established as soon as the sufficient signal quality is acknowledged by the FRMCS and mobile communication unit.
  • The transfer of multimedia databases from ground to train is started.
  • The mobile communication system forwards the transferred multimedia databases further into the in-train storage.
  • The transfer of multimedia archives continues as long as sufficient connection between the train and ground system is available and/or aborted by the FRMCS.
4.2.2  RequirementsWord-p. 10
4.3  Massive Inter-carriage data transfer
4.3.1  Description
The inter-carriage links between train vehicles enable sufficient capacity to enable massive data transfer throughout the train required e.g. for transfer of CCTV archives, multimedia databases and live streaming as well as for control, operational, and passenger services. Mobile communication unit in train provides connection between carriages of the train used, e.g. for the transfer of CCTV archives to a central node in the train form which the connection to the ground system will take place.
4.3.2  Requirements
4.4  Coexistence of automated train control with other train applications
4.4.1  Description
Train automation can be divided into control and operations. Both types consist of distributed applications that rely on dependable communication. Typically, control applications such as for automated train control are of higher priority than operational applications, and the latter are typically of higher priority than passenger services. One of the main challenges is to guarantee the premium priority of control-related communication over other types of communication, especially since the data bandwidth consumed for control is typically dwarfed by data traffic stemming from the other two application areas. Another challenge is to guarantee the super priority of operational data communication over passenger-related communication. Driverless trains are not the only source of automation in mass transit, and thus not the only source of dependable machine-type communication. For instance, mass transit train control (MTTC) including communication-based train control (CBTC) is also used for trains exhibiting lower grades of automation, if assisted by rail-to-rail-side wireless communication, which is at the core of driverless trains.
Communication services for MTTC have to coexist with other high-priority and low-priority communication services. This coexistence is done assigning priorities to the communications, see below an example of how these priorities can be allocated:
  • The MTTC communication service might have the highest priority (train control).
  • The CCTV communication service might have high-priority, but lower than MTTC.
  • (High data rate) data communication services such as passenger internet access might be of low priority.
  • Emergency calls need to be established on demand with a priority suitable to guarantee call success independent of already running communication services.
    NOTE: This kind of emergency calls is using the train and rail infrastructure and not the public emergency services. An example for a train emergency system are microphone/speaker boxes that are integrated into the walls of the passenger area.
The setup of high data rate communication services with low priority does not have an impact on the communication services for train control. Furthermore, the start-up of a communication service for train control will acquire sufficient resources in the 5G network, even if high data rate communication services with low priority are already running.
4.4.2  RequirementsWord-p. 11
5  Performance requirements for main line
6  Performance requirements for rail-bound mass transitWord-p. 14
A  Change historyWord-p. 17

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