Abstract: A new simple method is presented in this paper for solving the crosstalk between a single wire and a twisted-wire pairabove the ground. The twisted pair is modeled as a cascade of loops consisting of uniform two-wire sections with abrupt interchangesof wire positions at the end of each loop. Then, with the concept of generalized multi-port network, the voltage control equationbetween the two wires is established. Finally, the time-domain results are obtained through the finite-difference time-domain (FDTD)method. It is found that the simulation results obtained by using the method proposed in this paper agree very well with theexperimental results.