Abstract
Global Navigation Satellite System (GNSS) Galileo is expected to play an essential role in railway transport with view to reduce operational, investment and maintenance costs. However, quality requirements of the GNSS originate mainly from the aviation suggestions. Different safety philosophies used in aviation domain and in railway signaling complicate direct employment of the GNSS quality measures to the railway telematic applications. The objective of this paper is to outline the conception of railway requirements specification for the GNSS in order to cover a large amount of the appropriate applications in the non-safety and safety related domains. The elaborated methodology enables to provide specification of minimal quantitative requirements for GNSS system by means of railway attributes RAMS. This process generally represents contribution for GNSS system certification, when it is necessary to demonstrate that the GNSS system meets requirements, and the system outputs are correct. In the second level, certification of the specific GNSS application must follow subsequently.
