IEC 61850-9-2:2011 defines the specific communication service mapping 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. Main changes with respect to the first edition are:
- addition of an optional link redundancy layer,
- redefinition of "reserved" fields in link layer,
- evolution of USVCB and MSVCB components,
- evolution of encoding for the transmission of the sampled value buffer.