The FRS requirement 2.3.13 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 Notified Body (NoBo) has to verify that, if the network is going to be used for ETCS L2 or 3, it supports data communications.
In 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). There is currently no mandatory quality of service (QoS) stated in the CCS 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 and so, has to be considered as informative document. NoBos do not have to check compliancy against it, unless a specific section is explicitly referred to in a mandatory requirement.
The required quality of service is currently a matter to be agreed at the project level. The check of the fulfilment of the required quality of service is out of the scope of the NoBo verifying the subsystem. An 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.
In 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.