Abstract: A master device, a slave device, and methods are disclosed. The method is performed by a first slave device connected to a master-slave tree network, comprising: determining whether a beacon has not been received within a predetermined time period; and distributing a first beacon to a second slave device if no beacon has been received within the predetermined time period; wherein for the first slave device to remain in the master-slave-network, a beacon be received by the first slave device within the predetermined time period.

Abstract: Provided are a network slave node and a time synchronization method using precision time protocol-like (PTP-like) in a network. The network slave node includes a packet detection unit for detecting whether the slave node receives or sends a synchronization protocol packet and recording a synchronization protocol packet receiving time and a synchronization protocol packet sending time; a hardware clock; and a control unit controlling the packet detection unit and the hardware clock. The control unit reads out the packet receiving time and the packet sending time from the packet detection unit and informs a local master node. The local master node calculates a time offset between the local master node and the slave node, and informs the control unit. The control unit adjusts the hardware clock based on the time offset so that the local master node and the slave node are time synchronized.

Abstract: In a communication network, a network connection apparatus accepts timing information of a grand master to achieve timing synchronization. Next, the network connection apparatus requests slave nodes to be in timing synchronization with itself to achieve the timing synchronization. Even when the grand master is removed or crashed, when a new slave node is added, or when a hack node tries to hack the communication network, the network connection apparatus still periodically requests the slave nodes to be in timing synchronization with itself so that the timing synchronization inside the communication network is not negatively affected.

Abstract: Provided are a network slave node and a time synchronization method using precision time protocol-like (PTP-like) in a network. The network slave node includes a packet detection unit for detecting whether the slave node receives or sends a synchronization protocol packet and recording a synchronization protocol packet receiving time and a synchronization protocol packet sending time; a hardware clock; and a control unit controlling the packet detection unit and the hardware clock. The control unit reads out the packet receiving time and the packet sending time from the packet detection unit and informs a local master node. The local master node calculates a time offset between the local master node and the slave node, and informs the control unit. The control unit adjusts the hardware clock based on the time offset so that the local master node and the slave node are time synchronized.

Abstract: In a communication network, a network connection apparatus accepts timing information of a grand master to achieve timing synchronization. Next, the network connection apparatus requests slave nodes to be in timing synchronization with itself to achieve the timing synchronization. Even when the grand master is removed or crashed, when a new slave node is added, or when a hack node tries to hack the communication network, the network connection apparatus still periodically requests the slave nodes to be in timing synchronization with itself so that the timing synchronization inside the communication network is not negatively affected.