Point-to-multipoint communication in Power Line Networks: A novel FDM access method

In Power Line Networks, a link adaptation is realized by combining Multi-Carrier modulations techniques and bit-loading algorithms, resulting in the creation of tone maps. A tone map defines, for each subcarrier on a particular transmission path, the appropriate constellation that has to be applied based on a link quality criterion. Now, a frequently encountered situation happens when one station is requested to forward simultaneously multiple services to several stations of the network. Considering the fact that current PLC networks only work in a Time Division Multiplexing mode, the transmission efficiency in a point-to-multipoint scenario is not optimal. In this paper, we present a novel and practical algorithm, called TMSA (Tone Maps Splitting Algorithm), meant to split already defined point-to-point tone maps. It results in the definition of a Frequency Division Multiplexing mode to handle point-to-multipoint transmissions, efficiently exploiting the frequency diversity naturally present in the tone maps. Note that the proposed solution could work with other technologies, as long as quasi-static channels can be assumed and bit-loading algorithms are used.