This document specifies the methodology to define the train related braking model and required brake on-board parameters to enable speed and distance monitoring for trains equipped and operated on railway lines using ETCS Baseline 3. This document is only applicable for ETCS Gamma braking model trains (i.e. the train is said to be a gamma train). This document does not specify the way these parameters are transferred to and can be used by the ETCS on-board system (e.g. during start of mission - SoM). The ETCS conversion models are not covered by this document and are described in EN 16834:2019, Annex F. The ETCS conversion models are intended for use with trains where the braking performance is expressed using braked weight percentages ( lambda train). Any trackside related input parameters, including national values, are not covered in this document. Information can be found in the SUBSET-026 (see [11]).