IEC 62056-8-5:2017(E) specifies the IEC 62056 DLMS/COSEM communication profile for metering purposes based on the Recommendations ITU-T G.9901: Narrowband orthogonal frequency division multiplexing power line communication transceivers - Power spectral density specification and ITU-T G.9903:2014, Narrowband orthogonal frequency division multiplexing power line communication transceivers for G3-PLC networks, an Orthogonal Frequency Division Multiplexing (OFDM) Power Line Communications (PLC) protocol.