Abstract: A communication path in a loop form is formed by trunk lines and a redundant communication path, which is formed by a switch and a backup line. In order to be applied to a bus-type communication network such as a CAN, the switch is normally off, and the backup line is disconnected from a path in a steady state. A disconnection detection unit is provided at each of joint connectors. When any disconnection detection unit detects disconnection, the switch is closed to enable use of the redundant path. Further, content of a routing map of a central gateway is automatically rewritten to preferentially select the redundant path that is not disconnected, and thus the path is changed.

Abstract: Switching hubs such as relay devices capable of path control are arranged at a plurality of branch positions respectively on a wire harness including a trunk line of a communication line. Each of the relay devices includes a failure detection part, a routing map, and a path control part. The trunk line of the communication line is formed to make it possible to use a plurality of types of paths selectively. When the failure detection part in any relay device detects a failure, an instruction of path change is given to another relay device therefrom. When any relay device receives an instruction of path change from another relay device, the routing maps in the relay device receiving the instruction are switched according to a failure occurrence portion. A VLAN is constructed on an Ethernet communication network, and logical assignment of the VLAN is controlled by a central gateway.

Abstract: A plurality of zones is formed in a communication network on the vehicle, and a communication path in a loop form is formed in each zone by zone trunk lines and a backup line. The backup line is connected by a switch only at the time of disconnection so that the loop is not closed. At the time of disconnection detection, an instruction is automatically given to rewrite content of routing maps on zone ECUs and a central gateway. Since each node preferentially selects a communication path that bypasses a disconnection portion from the start of communication by rewriting the content of the routing maps, it is possible to avoid an increase in communication delay. An inter-zone backup line connecting a plurality of zones is provided to enable the use of a new path across the plurality of zones at the time of disconnection.

Abstract: Switching hubs such as relay devices capable of path control are arranged at a plurality of branch positions respectively on a wire harness including a trunk line of a communication line. Each of the relay devices includes a failure detection part, a routing map, and a path control part. The trunk line of the communication line is formed to make it possible to use a plurality of types of paths selectively. When the failure detection part in any relay device detects a failure, an instruction of path change is given to another relay device therefrom. When any relay device receives an instruction of path change from another relay device, the routing maps in the relay device receiving the instruction are switched according to a failure occurrence portion. A VLAN is constructed on an Ethernet communication network, and logical assignment of the VLAN is controlled by a central gateway.

Abstract: A communication path in a loop form is formed by trunk lines and a redundant communication path, which is formed by a switch and a backup line. In order to be applied to a bus-type communication network such as a CAN, the switch is normally off, and the backup line is disconnected from a path in a steady state. A disconnection detection unit is provided at each of joint connectors. When any disconnection detection unit detects disconnection, the switch is closed to enable use of the redundant path. Further, content of a routing map of a central gateway is automatically rewritten to preferentially select the redundant path that is not disconnected, and thus the path is changed.

Abstract: A plurality of zones is formed in a communication network on the vehicle, and a communication path in a loop form is formed in each zone by zone trunk lines and a backup line. The backup line is connected by a switch only at the time of disconnection so that the loop is not closed. At the time of disconnection detection, an instruction is automatically given to rewrite content of routing maps on zone ECUs and a central gateway. Since each node preferentially selects a communication path that bypasses a disconnection portion from the start of communication by rewriting the content of the routing maps, it is possible to avoid an increase in communication delay. An inter-zone backup line connecting a plurality of zones is provided to enable the use of a new path across the plurality of zones at the time of disconnection.