Specifies the electrical and/or optical and physical characteristics of the transmissions medium; specifies the electrical or optical signalling method used; specifies the frame formats transmitted; specifies the actions of a station upon receipt of a frame, and specifies the services provided at the conceptual interface between the medium access control sublayer and the logical link control sublayer above it. This Standard is identical with and has been reproduced from ISO/IEC 8802-4:1990.
