Proposed in 1969 and initially referred to as a
Newhall ring.
Token ring :: a number of stations connected by
transmission links in a ring topology. Information
flows in one direction along the ring from source
to destination and back to source.
Medium access control is provided by a small frame,
the token, that circulates around the ring when all
stations are idle. Only the station possessing the
token is allowed to transmit at any given time.