PROTOCOLS FOR TRANSMISSI0N OF DATA, IN PARTICULAR OVER TELEPHONE LINES

摘要

AbstractProtocols for transmission of data, in particular over telephone lineNew features are proposed for protocols for transmitting data through linessuch as telephone lines. A first proposal is that the tones of a signal aregrouped, and that Trellis encoding is applied within each group. A secondproposal is that tone ordering, bit swapping and selection of paths is done within the members of a group. A third proposal is that the sizes of the bands for the transmit and/or receive directions are selected so as to permit an efficient IFFT. A fourth proposal is that the number of tones in a low powermode is reduced, such that only a selected number of the tones are present inthe signal input to the IFFT. A fifth proposal is that the number of tones is reduced and the number of frequency components increased by up-sampling to create the VDSL spectrum. A sixth proposal is to effect the low power mode by following a different standard having a lower data transmission rate, suchas one according to an ADSL standard.Figure 4