A method in a node of a telecommunication network comprises receiving a digital communication signal from a first signal source, source, wherein the digital communication signal comprises a wherein the digital communication signal comprises a plurality of low amplitude windows, step 101, and receiving one or more analog subcarrier signals from a second signal source, step 103. The method further comprises multiplexing the one or more analog subcarrier signals into one or more of the plurality of low amplitude windows of the digital communication signal, step 105.