Patent ID: 7496144

Claim:
A method of two-directional communication of data over a line, the communication employing a bandwidth partitioned into a number of bands and including at least one band associated with each of the two directions, the method including encoding the data carried in each direction by modulation of a plurality of tones defined within the at least one band associated with that direction, the tones being associated into a plurality of groups of tones, each group of tones including a plurality of the tones, the method including for each group of tones: deriving a measure of the quality of transmission of each of the tones; obtaining data, respective portions of the data being associated with respective groups of the tones; modulating the tones of the group to encode the associated portion of the data, the relative transmission quality of the tones of the group determining how the tones of that group are modulated to encode the data, wherein a respective proportion of the data to be carried by each tone of the group is determined for each tone of the group; re-determining the measure of the quality of transmission of each of the tones of the group; and according to said redetermination of the quality of transmission of the tones on the line, modifying within the group the respective proportions of the data encoded using the tones.