PURPOSE: To improve the trouble resistance of a communication network by connecting a host to plural optional nodes and an optional node to plural hosts so that a message originated from the host is simultaneously transmitted to the communication network through plural nodes or the same message is received from the plural nodes connected to the host.
CONSTITUTION: The message simultaneously transmitted from a host H2:200 is not transmitted to nodes N1, N2, N3, N9:1, 2, 3, 9 because of a trouble 800 of the transmission line. In this case, a host H1 detects that the same message is not received from the nodes N2, N3, and after checking both the ways of the nodes N2, N3, sends the same messages 722, 721 as 742, 715 to the nodes N2, N3. The nodes N2, N3 start simultaneous transmission independently, so that message transmission 723→729 is started. Consequently, a host H4:400 can receive the message transmitted from the host H2.
NAKANO TOORU
NOGUCHI TETSUROU
MORI KINJI
