A method of transmitting a set of data signals over a plurality of pairs of wires (1691, 1692, 1693) numbering three or more pairs of wires, the data signals comprising a first subset of data signals and a second subset of data signals, each of the first and second subsets of data signals comprising at least two different data signals, the method comprising: generating a first set of transmission signals using an orthogonal discrete coding transformation unit, each transmission signal in the first set of transmission signals being derived from a combination of all of the data signals in the first subset of data signals; generating a second set of transmission signals, each transmission signal in the second set of transmission signals being derived from a single respective one of the data signals in the second subset of data signals, generating the first and second sets of transmission signals includes using an Inverse Fast Fourier Transform unit to perform an inverse fast Fourier transformation of the transmission signals, wherein the step of generating the first set of transmissior signals using the orthogonal discrete coding transformation unit takes place before the step of generating the first set of transmission signals using the Inverse Fast Fourier Transform unit to perform the inverse fast Fourier transformation of the transmission signals; transmitting each of the transmission signals in the first set of transmission signals in a common mode over a respective one of the plurality of pairs of wires (1691, 1692, 1693); and transmitting each of the transmission signals in the second set of transmission signals over a respective one of the plurality of pairs of wires (1691, 1692, 1693) in a differential mode, wherein the method further comprises the step of forming the combination of all the data signals in the first subset of data signals, which includes generating a dummy data signal which does not contain any data which needs to be recovered at a receiver device connected to the plurality of pairs of wires (1691, 1692, 1693) at distal ends thereof and including the dummy signal in each combination of data signals to form each transmission signal in the first set of transmission signals. generating a first set of transmission signals using an orthogonal discrete coding transformation unit, each transmission signal in the first set of transmission signals being derived from a combination of all of the data signals in the first subset of data signals; generating a second set of transmission signals, each transmission signal in the second set of transmission signals being derived from a single respective one of the data signals in the second subset of data signals, generating the first and second sets of transmission signals includes using an Inverse Fast Fourier Transform unit to perform an inverse fast Fourier transformation of the transmission signals, wherein the step of generating the first set of transmissior signals using the orthogonal discrete coding transformation unit takes place before the step of generating the first set of transmission signals using the Inverse Fast Fourier Transform unit to perform the inverse fast Fourier transformation of the transmission signals; transmitting each of the transmission signals in the first set of transmission signals in a common mode over a respective one of the plurality of pairs of wires (1691, 1692, 1693); and transmitting each of the transmission signals in the second set of transmission signals over a respective one of the plurality of pairs of wires (1691, 1692, 1693) in a differential mode, wherein the method further comprises the step of forming the combination of all the data signals in the first subset of data signals, which includes generating a dummy data signal which does not contain any data which needs to be recovered at a receiver device connected to the plurality of pairs of wires (1691, 1692, 1693) at distal ends thereof and including the dummy signal in each combination of data signals to form each transmission signal in the first set of transmission signals.