Patent ID: 8537912

Claim:
An apparatus comprising: a plurality of parallel digital signal transmitters that each receive one of a plurality of digital sub-signals wherein each of the plurality of digital signal transmitters is configured to transmit one of the plurality of digital sub-signals that each have about the same bandwidth; and a combiner coupled to the transmitters and configured to shift some of the plurality of digital sub-signals and to combine the plurality of shifted digital sub-signals into a combined digital signal that has a total bandwidth of the plurality of digital sub-signals, wherein the total bandwidth of the combined digital signal is approximately equal to the sum of the bandwidths of the plurality of digital sub-signals; wherein the total bandwidth comprises a plurality of shifted bandwidths of the plurality of digital sub-signals at about the same offset with respect to each other, wherein the combined digital signal is transmitted over a digital subscriber loop, and wherein the digital signal transmitters are coupled to a plurality of second parallel digital signal receivers via N physical pairs of electrically conducting wires, where N is an integer, and wherein 2N−1 pairs of electrically conducting wires comprise N pairs of physical wires using a regular differential mode and up to N−1 virtual pairs using a common mode or an alternative mode.