This part of 61850 defines the specific communication service mapping (SCSM) for the transmission of sampled values according to the abstract specification in IEC 61850-7-2. The mapping is that of the abstract model on a mixed stack using direct access to an ISO/IEC 8802-3 link for the transmission of the samples in combination with IEC 61850-8-1. Each SCSM consists of three parts: - a specification of the communication stack being used, - the mapping of the abstract specifications of IEC 61850-7 series on the real elements of the stack being used, and - the implementation specification of functionality, which is not covered by the stack being used.