1. An arrangement for analyzing or predicting one or more transmission line properties, comprising: a measurement data providing means for providing measurement data of a first time or frequency dependent property of a transmission line, a transmission line property calculation arrangement, which comprises a transmission line model handling means providing a transmission line model, a Hilbert transform handler and line property determination means, and which is arranged to provide a calculation of the said first property based on a number of model parameters, wherein the model parameters comprise or are related to at least two of the transmission line properties or quantities, a line resistance at 0 frequency, r oc , a cut-off frequency, v, a line capacitance, C ∞ , and a line inductance, L ∞ H , or one or more relationships therebetween, wherein the line model handling means are adapted to calculate the transmission line inductance L(f), or an expression including the inductance L(f), using a Hilbert transform of a function of Q(f/v), wherein said function Q(f/v) relates the line resistance R(f) to r oc as R(f)=r oc ·Q(f/v), wherein said Q ⁡ ( f / v ) = 1 + ( x v ) 2 4 , wherein the Hilbert transform of Q(f/v) is defined by Λ ⁡ ( f v ) = - 1 π · ∫ - ∞ ∞ ⁢ 1 + ( x v ) 2 4 f - x ⁢ ⁢ ⅆ x , wherein f is line frequency, and x denotes an integration variable that spans a frequency range, and wherein values of the Hilbert transform are calculated using an analytical closed form expression or wherein alternatively values of the Hilbert transform are tabulated or approximated by a polynomial, and in that, for model parameter values calculated by means of the line model handling means in communication with the Hilbert transform handler, the line property determination means are adapted to calculate the first property, that further criteria function application means being in communication with the line property determination means and the measurement data providing means are arranged to, using the measured first property and the calculated first property for a given set of model parameters, find optimized numerical model parameter values for which one or more given criteria are met.