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: A system and a method for transmitting network packets are provided. The system includes an information module, a scheduling module, and a forwarding module. The information module receives and records media information of a plurality of multimedia streams. The scheduling module calculates a guaranteed bit rate of each multimedia stream according to the media information provided by the information module, and rearranges isochronous packets of the multimedia streams in the first time slots of a plurality of clock cycles according to the guaranteed bit rates so that the transmission of the isochronous packets satisfies the guaranteed bit rates. The length of each clock cycle is a predetermined length. The length of the first time slot and the predetermined length are in a predetermined ratio. The forwarding module transmits all the packets of a clock cycle to a network at every a time interval of the predetermined length.

Abstract: A method and an apparatus for encrypting/decrypting packet data of a precise time synchronization protocol and a time synchronization system are illustrated. The method is suitable for the time synchronization system using a precise time protocol. The time synchronization system includes a master node and a slave node, wherein the slave node synchronizes its time with the master node. In the method for encrypting/decrypting packet data of the precise time synchronization protocol, an encryption/decryption hardware device is disposed on the hardware protocol layer of each of the master node and the slave node. The hardware protocol layer is under the data link layer, and includes the data link layer. A synchronization message is encrypted by using the encryption/decryption hardware devices of the master node to generate a frame data, and the frame data is decrypted by using the encryption/decryption hardware devices of the slave node to obtain the synchronization message.

Abstract: A system and a method for transmitting network packets are provided. The system includes an information module, a scheduling module, and a forwarding module. The information module receives and records media information of a plurality of multimedia streams. The scheduling module calculates a guaranteed bit rate of each multimedia stream according to the media information provided by the information module, and rearranges isochronous packets of the multimedia streams in the first time slots of a plurality of clock cycles according to the guaranteed bit rates so that the transmission of the isochronous packets satisfies the guaranteed bit rates. The length of each clock cycle is a predetermined length. The length of the first time slot and the predetermined length are in a predetermined ratio. The forwarding module transmits all the packets of a clock cycle to a network at every a time interval of the predetermined length.

Abstract: A method and an apparatus for encrypting/decrypting packet data of a precise time synchronization protocol and a time synchronization system are illustrated. The method is suitable for the time synchronization system using a precise time protocol. The time synchronization system includes a master node and a slave node, wherein the slave node synchronizes its time with the master node. In the method for encrypting/decrypting packet data of the precise time synchronization protocol, an encryption/decryption hardware device is disposed on the hardware protocol layer of each of the master node and the slave node. The hardware protocol layer is under the data link layer, and includes the data link layer. A synchronization message is encrypted by using the encryption/decryption hardware devices of the master node to generate a frame data, and the frame data is decrypted by using the encryption/decryption hardware devices of the slave node to obtain the synchronization message.