Modelling of metallic cables at G.fast frequencies

Metallic cables are still frequently used in access telecommunications networks, especially in the last-mile network segments, together with digital subscriber line (DSL) technologies. Recently, the G.fast system for reaching gigabit transmission speed over short metallic lines has been introduced. In order to achieve such performance, the frequency band of G.fast was extended up to 106 MHz or 212 MHz and several innovative transmission concepts were adopted as well. However, these innovations require accurate approximations of a G.fast transmission channel. Due to that it is necessary to provide accurate approximation of metallic cable transmission characteristics, the attenuation constant α(f) as well as the phase constant β(f). Therefore, an innovative LN model was proposed and is presented in this paper. Its main motivation is to outperform the existing models with equal number of necessary parameters. The accuracy of a proposed LN model was tested for various metallic cables and compared with two typical existing models.