This part of IEC 62056 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: Narrowband orthogonal frequency division multiplexing power line communication transceivers for G3-PLC networks, an Orthogonal Frequency Division Multiplexing (OFDM) Power Line Communications (PLC) protocol. The physical layer provides a modulation technique that efficiently utilizes the allowed bandwidth within the CENELEC A (3 kHz 95 kHz), CENELEC B (95 kHz 125 kHz), ARIB (10 kHz 450 kHz) and FCC (no specific frequency band limitations) bands, thereby allowing the use of advanced channel coding techniques. This enables a robust communication in the presence of narrowband interference, impulsive noise, and frequency selective attenuation. The medium access control (MAC) layer allows the transmission of MAC frames through the use of the power line physical channel. It provides data services, frame validation control, node association and secure services. The 6LoWPAN adaptation sublayer enables an efficient interaction between the MAC and the IPv6 network layer. The use of the IPv6 network protocol the latest generation of IP protocols opens a wide range of potential applications and services for metering purposes (but the applications are not limited to metering). The transport layer, the application layer and the data model are as specified in the IEC 62056 DLMS/COSEM suite. NB: The scope of this communication profile standard is restricted to aspects concerning the use of communication protocols in conjunction with the COSEM data model and the DLMS/COSEM application layer. Data structures specific to a communication protocol are out of the Scope of this communication profile standard. NOTE They are specified in the specific protocol standards. Any project specific definitions of data structures and data contents may be provided in project specific companion specifications.