This application relates to the field of communications technologies, and discloses a service forwarding method and a network device that performs such method. The method includes: forwarding, by a first network device, a data packet of a first service to a second network device in a period (T.sub.1); and if the data volume of the forwarded first service reaches a threshold, forwarding, by the first network device, a data packet of a second service to the second network device. The first service is a low-latency service, and the second service is a non-low-latency service. In addition, the period (T.sub.1) is determined based on a delay allowed by a device for forwarding the data packet of the first service, and the threshold is a value determined based on a maximum transmission rate of the first service.

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.

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.

Methods of synchronizing sequence numbers of a number of devices of a network are disclosed. A method may include resetting, at each of a first device and a second device of a network, a sequence number to an initial predetermined count value responsive to a timing event. The method may also include generating, at each of the first device and the second device, a frame for transmission. Further, the method may include incrementing, at each of the first device and the second device, the sequence number, wherein the sequence number is indicative of a number of frames generated at the associated device since the timing event. The method may also include inserting, at each of the first device and the second device, the sequence number into an associated frame. Related networks and devices are also disclosed.

Methods of synchronizing sequence numbers of a number of devices of a network are disclosed. A method may include resetting, at each of a first device and a second device of a network, a sequence number to an initial predetermined count value responsive to a timing event. The method may also include generating, at each of the first device and the second device, a frame for transmission. Further, the method may include incrementing, at each of the first device and the second device, the sequence number, wherein the sequence number is indicative of a number of frames generated at the associated device since the timing event. The method may also include inserting, at each of the first device and the second device, the sequence number into an associated frame. Related networks and devices are also disclosed.

A CANopen-based train network data transmission method includes: switching, when a first CAN channel of a first slave node is detected as faulty, to a second CAN channel of the first slave node to receive over a standby network a heartbeat packet and data transmitted by another relevant node; monitoring, if no heartbeat packet transmitted by a relevant second slave node is received from the standby network within a preset heartbeat period, by an active master node, in an active network, a heartbeat packet and data transmitted by the second slave node; receiving, through the second CAN channel, the heartbeat packet and the data of the second slave node forwarded by the active master node to the standby network when the active master node detects in the active network the heartbeat packet and the data transmitted by the second slave node through the first CAN channel.

The present disclosure discloses a CANopen-based train network data transmission method. The method includes: monitoring, on an active network, a heartbeat packet transmitted through a first CAN channel by each slave node related to an active master node; determining whether the first CAN channel of each slave node is faulty; transmitting a reset instruction to a first node from the active network if no heartbeat packet of the first node is received within the preset first heartbeat period; learning, if no heartbeat packet of the first node is received, that the first CAN channel of the first node is faulty, and switching to a standby network to monitor the heartbeat packet transmitted by the first node; otherwise, receiving, on the standby network, data transmitted by the first node, and also receiving, on the active network, data transmitted by other slave nodes that normally transmit heartbeat packets.

A fail-safe system for a cluster application is disclosed. The system includes a first subsystem comprising a graphic processing unit (GPU) that executes a high-level operating system renders a first set of parameter data, and a second subsystem that executes a real-time operating system and renders a second set of parameter data. The system also includes a controller area network connected to a parameter data source input and to the first subsystem and the second subsystem. The system further includes a quality of service (QoS) switch executing a QoS monitor module that decides to display the first set of parameter data being rendered by the first subsystem or the second set of parameter data being rendered by the second subsystem depending on an availability and load of the first subsystem as determined by a lag and a stability threshold. The system further includes a display connected to the QoS switch.

A method of controlling communication over a Local Interconnect Network (LIN) bus is provided. The method comprises a redundancy master node detecting whether or not a first master node responds to data transmitted over the LIN bus; wherein in case the first master node does not respond, the redundancy master node will act as master node on the LIN bus.

A fail-safe system for a cluster application is disclosed. The system includes a first subsystem comprising a graphic processing unit (GPU) that executes a high-level operating system renders a first set of parameter data, and a second subsystem that executes a real-time operating system and renders a second set of parameter data. The system also includes a controller area network connected to a parameter data source input and to the first subsystem and the second subsystem. The system further includes a quality of service (QoS) switch executing a QoS monitor module that decides to display the first set of parameter data being rendered by the first subsystem or the second set of parameter data being rendered by the second subsystem depending on an availability and load of the first subsystem as determined by a lag and a stability threshold. The system further includes a display connected to the QoS switch.