ERTMS
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FAQ on Railway Radio Communication  
 
Evolution of Railway Radio

What is the Agency doing?

  • The Agency is the System authority responsible for the adaptation of EU legal framework to technology evolution. As such, it is in charge of taking the necessary steps to propose this adaptation to the Member States.
  • It has started by organising a Coordination group, which is a forum to synchronise the related initiatives (taken by ETSI, UIC, Shift²Rail)

Is the Agency too late?

  • There is no indication of the need of broadband applications yet by the railway sector, for operational communications.
  • There is sufficient capacity with GSM-R and GPRS for the current railway operational needs

Why not deciding now?

  • There is a risk in the technology choice (4G vs. 5G), linked to the functionality commercially available, to the expected evolution of the standards, and the availability of products.
  • There is no further spectrum designated for railways, other than the one currently in use by GSM-R. Furthermore, 4G standard does not include the spectrum in use by GSM-R.
  • A technology independent architecture model needs to be developed to ensure the split between applications (voice and data) and technology. The aim is to get to a flexible architecture, where the influence of the evolution of the radio technology is minimized.

When to decide?

  • The Agency expects to have a High level System definition in 2018, for early deployments from 2022 onwards.
  • This “retro planning” is  based on indications from GSM-R Industry Group, who stated that products will be available until 2030.
  • The changes will be synchronised with the ERTMS Baseline planning.

What will happen with GSM-R?

  • There is commitment from GSM-R Industry to support GSM-R at least until 2030, which will ensure the transition.
  • The new system model includes GSM-R, in order to protect the investments.

What is the new system for?

  • To provide continuity of railway operational communication.
  • To support business related communication: maintenance, ticketing, energy metering.
  • In some cases, for passenger information.

What about WiFi onboard?

  • The possibility of offering this to the general public directly by railway companies depends on whether it is allowed in the regulation for telecommunication services.
  • It could be offered in partnership with public operators.
  • It may not necessarily be needed: the general trend for public operator obligations is to strengthen 4G coverage over rail tracks. In this case, a repeater on board could be sufficient to provide the service to the passengers.

What about replacing GSM-R with LTE already today?

  • The technologies that will be used in the future are not yet selected. It is clear that, when thinking about technologies currently available, LTE is the first one that comes  to our minds. However, at the moment, there are a number of uncertainties that do not allow to get to that conclusion.
  • There is no evidence that LTE can support voice and data traffic when moving at high speeds (over 250 km/h) with an adequate performance;  the current LTE specification does not fulfill all the railway requirements (Railway Emergency Calls, group calls, priority and preemption), as this is planned to be included in the next LTE Releases (13 and above), to be commercially available in some years; railways are entitled to use a spectrum band that is not included in the current LTE specification; the reliability of the network has to be sufficient to cope with the RAMS requirements for railways; etc…
  • A number of communication services can be made available to railways by using today’s LTE commercial networks, but this is not yet possible for the Railways Operational communications.
  • In addition, in the current legal European framework, the use of GSM-R is mandated for railway operational communications.

GSM-R Baseline 0 and 1

In the new TSI CCS we saw that GSM-R Baseline 0 is no longer referenced. Does that mean that an EDOR without GPRS is not useable in future projects, even in ETCS B2 projects?
 
  • The two main changes that are included in GSM-R B1 for EDOR are: protection against interferences and support of PS. It was imperative to make mandatory the protection against interferences for all the onboards, which forced the inclusion of GSM-R B1 in the three Sets of documents in the Annex A.
  • Strictly speaking, only B1 compliant EDORs (protected against interferences and supporting PS) can be certified as conform to the new CCS TSI. However, the requirements for the subsystems have to be taken to the subsystem level. An IC that presents some limitations may be used in a subsystem, if the resulting subsystem is fully compliant (without limitations) to the CCS TSI  new system model includes GSM-R, in order to protect the investments.

For example:

a)  An EDOR that is protected against interferences but does not support PS may receive a certificate of conformity to the new CCS TSI (GSM-R B1) with a restriction/limitation (it does not implement the PS functionalities).  
      - This IC could be integrated in an onboard subsystem where Set#3 of the Annex A is not the selected one (this means, with ETCS version < B3 R2). The resulting onboard subsystem will be compliant to the CCS TSI (GSM-R B1), without any restriction.
b)  An EDOR that is conform to GSM-R B0 is not protected against interferences and does not implement PS. It could be understood as equivalent to being compliant to the GSM-R B1 with the restrictions/limitations mentioned. 
      - This IC could be integrated in an onboard subsystem where Set#3 of the Annex A is not the selected one (this means, with ETCS version < B3 R2) AND where an external filtering device is fitted (to provide the required protection against interferences).
      The resulting onboard subsystem will be compliant to the CCS TSI (GSM-R B1), without any restriction.