mode transmission effects on the power line. In fact, by considering the MTRL PUL equivalent circuit, the series resistances do not only represent the ohmic losses but also the radiation losses as follows: $$r_c = r^{DM}_{c-b}+r^{Ohm}_c,$$ $$r_b = r^{DM}_{b-a}+r^{Ohm}_b,$$ $$r_a = r^{DM}_{a-c}+r^{Ohm}_a,$$ $$r_o = r^{CM}+r^{Ohm}_o,$$ where $a$, $b$ and $c$ are the conductors wrapped into the cable and $o$ is the reference ground. With this model, a series resistance for each wire accounts for the radiation losses due to differential signaling between that wire and another one. Moreover, a series resistance on the ground reference accounts for the radiation losses due to the common mode signaling that passes through the cable and closes its path through the ground.

In order for such a model to be extendible to a cable of any length, some simplifications need to be made for the models of $R^{DM}$ and $R^{CM}$, since they do not increase linearly with the cable length. As for $R^{DM}$, we can consider $r^{DM}$ to be equal to $R^{DM}_\infty/\lambda$, where $R^{DM}$ is the total DM radiation resistance of a semi-infinite cable, up to $L=\lambda$. This is because, as shown in Section \[sec:radiation\], the value of $R^{DM}$ can be considered a constant 