Physical signaling sublayer (PLS): In a
local area network (LAN) or a
metropolitan area network (MAN) using
open systems interconnection (OSI) architecture, the portion of the
physical layer that (a) interfaces with the
medium access control sublayer[?], (b) performs
character encoding,
transmission, reception, and decoding, and (c) performs optional isolation functions.
Source: from Federal Standard 1037C