1. Are Subsets 119, 120 and 121 mandatory in the CCS TSI?
Are these subsets mandatory and do NoBos have to check
3 subsets are NOT mandatory at the moment.
- Subset 121 is
NOT listed in the CCS TSI Annex A, nor in the informative documents of the CCS
TSI Application Guide. Obviously, as it is not listed in the CCS TSI, it is not
- Subsets 119
and 120 are listed in the CCS TSI without version and with a note (“Reference
to these specifications will be published in the Application Guide, waiting for
clarifications on the rolling stock side of the interface”). The intention
is to make them mandatory, once an agreement is reached on the content. At that
moment, they will be included in the Annex A of the CCS TSI. Work has not
finished yet. Therefore, in the meantime, they have to be considered as
Guide documents are informative: NoBos do not have to check compliancy to
2. Do NoBos have to check the fulfilment of Subset-093 when assessing a
In EIRENE FRS, the following requirement is found:
2.3.13 Where ERTMS/ETCS level 2 or 3 is
implemented, the network shall be capable of supporting data communications for
that train control system with the
required quality of service. (MI)
And in EIRENE SRS:
2.11.1 Where ERTMS/ETCS level 2
or 3 is implemented, the Quality of Service requirements as specified in
document [SUBSET 093] and the test specification [ERTMS/GSM-R QoS Test
Specification] are applicable. (I)
Is it the NoBo task to check the performance
requirements in order to assess the compliancy to FRS 2.3.13?
FRS requirement 2.3.13 (MI) imposes the obligation in the network to support
data communications in case it is going to be used for ETCS Level 2 or 3. This
is the reason for classifying this requirement as MI (mandated by the CCS TSI).
The NoBo has to verify that, if the network is going to be used for ETCS L2 or
3, it supports data communications.
the FRS, the meaning of the clause is that the network should be prepared for
the data communication. In fact, SRS 3.2.2 and 3.2.3 have to be fulfilled (and
verified by the NoBo).
is currently no mandatory quality of service stated in the TSI, therefore, the
reference to the “required quality of service” is not to be understood as
something to be verified by the NoBo.
Subset-093 is listed in the CCS TSI Application
Guide. Application Guide documents are informative: NoBos do not have to
check compliancy to them in general, unless a specific section is explicitly
referred to in a mandatory requirement.
required quality of service is currently a matter to be agreed at the project
level. The check of the fulfillment of the required quality of service is out
of the scope of the NoBo verifying the subsystem.
assessor can be requested to check many additional items, in addition to those
required by the TSI. This may be done, but always outside of the process for
verification of the subsystem, as additional checks if requested by the
applicant, in which case the assessor will be acting as a technical expert and
not as NoBo.
order to make clear the scope of the verification carried out for the FRS
2.3.13 requirement, a note in the Technical file can be added, stating that there
is no specific QoS required in the CCS TSI, and therefore, no Qos verification
has been done.
3. Why is Subset-093 not mandatory in the CCS TSI?
GSM-R performance is important for the safe
integration between GSM-R and ETCS. ETCS suppliers ask for the evidence related
to Subset-093 and they want to see it in the GSM-R EC Certificate.
the performance of the radio network is very important to allow the ETCS Level
2 or 3 service to be operational. However,
there is no definitive agreement on mandatory performance requirements for the
network (Trackside subsystem) or for the different Interoperability Constituents
(EDOR, ETCS on board-EVC, RBC), nor on the way to measure their performance. In
this situation, the assessment by a NoBo is not possible.
includes requirements between the interface of the EVC and the EDOR, and the
interface between the GSM-R network and the RBC. This does not correspond with
the entities that the NoBo has to assess (Subsystems or ICs, as defined in the
CCS TSI). Therefore, the document, as it is, is not suitable for the assessment
of the Trackside subsystem or for the EDOR.