This Technical Specification is part of the EN 62056 / 52056 DLMS/COSEM suite and specifies the DLMS/COSEM communication profile for compatibly extendable power line carrier neighbourhood networks using Adaptive Multi-Carrier Spread-Spectrum (AMC-SS). The physical layer provides a modulation technique that efficiently utilizes the allowed bandwidth within the CENELEC A band (3 kHz – 95 kHz), offering a very robust communication in the presence of narrowband interference, impulsive noise, and frequency selective attenuation. The physical layer of AMC-SS is defined in Clause 5 of CLC/FprTS 50590:2014. The data link (DL) layer consists of three parts, the ‘Medium Access Control’ (MAC) sub-layer, the Logical Link Control (LLC) sub-layer and the ‘Convergence’ sub-layer. The data link layer allows the transmission of data frames through the use of the power line physical channel. It provides data services, frame integrity control, routing, registration, multiple access, and cell change functionality. The MAC sub-layer and the LLC sub-layer of AMC-SS are defined in Clause 6 of CLC/FprTS 50590:2014. The Convergence sub-layer is defined in this document. The transport layer, the application layer and the data model are as specified in the EN 62056 DLMS/COSEM suite.