Data communication system, computer-implemented method for data communication in a railway network, computer program and non-volatile data carrier

A data communication system for a railway network (300), which comprises:

• at least one measurement controller (130) configured to:
• in a respective one of at least one rail vehicle (100) of a data-supplier type,
• obtain a basic parameter (μ) reflecting an initial value of a friction coefficient (μe) relating to a rail segment (310) in the railway network (300), and
• produce a validated value of the basic parameter (μ), which validated value reflects an updated friction coefficient (μe) between the rail (140) of the rail segment (310) and the wheels (151, 152, 153, 154) of the respective one of the at least one rail vehicle (100) of the data-supplier type, and which validated value is produced through a procedure involving:
• measuring individual rotational speeds (ω1, ω2, ω3, ω4) of the axles to which the wheels (151, 152, 153, 154) of the at least one first rail vehicle are connected while applying a gradually increasing brake force (BF) to a specific one of said axles,
• determining, while applying the gradually increasing brake force (BF), an absolute difference between the rotational speed (ω2) of the specific one of said axles and an average rotational speed of said axles except the specific one of said axles, and in response to the absolute difference exceeding a threshold value,
• deriving a parameter (μm) reflecting a measured value of the friction coefficient (μe),
• checking whether the measured value of the friction coefficient (μe) lies within an acceptance interval from the basic parameter (μ), and if so
• assigning the validated value equal to the measured value of the friction coefficient (μe), and
• at least one transmitter apparatus (120) configured to:
• in a respective one of at least one rail vehicle (100) of the data supplier type, and
• emit a friction data message (M(μe)) containing the validated value of the friction coefficient (μe);
• and
• a set of receiver apparatuses (110) each of which is configured to:
• in at least one rail vehicle (100, 312, 313, 314) in the railway network (300),
• receive the friction data message (M(μe)).