Abstract: Embodiments of the present invention provide a method and a device for synchronizing an uplink ciphering parameter in unacknowledged mode. The method for synchronizing an uplink ciphering parameter in unacknowledged mode includes: sending an indication message to a terminal when detecting that an unrecoverable error occurs in an uplink packet or that the uplink packet is invalid, where the indication message is used to instruct the terminal to initialize an uplink ciphering parameter; receiving a response message sent by the terminal; and initializing the uplink ciphering parameter according to an initial value of the ciphering parameter. The embodiments of the present invention solve a service defect, namely, a break of the communication link caused by synchronization of an uplink ciphering parameter between the terminal and the radio network controller in unacknowledged mode, and shorten the time of synchronizing the uplink ciphering parameter without interrupting the service.

Abstract: Embodiments of the present invention provide a method and a device for synchronizing an uplink ciphering parameter in unacknowledged mode. The method for synchronizing an uplink ciphering parameter in unacknowledged mode includes: sending an indication message to a terminal when detecting that an unrecoverable error occurs in an uplink packet or that the uplink packet is invalid, where the indication message is used to instruct the terminal to initialize an uplink ciphering parameter; receiving a response message sent by the terminal; and initializing the uplink ciphering parameter according to an initial value of the ciphering parameter. The embodiments of the present invention solve a service defect, namely, a break of the communication link caused by synchronization of an uplink ciphering parameter between the terminal and the radio network controller in unacknowledged mode, and shorten the time of synchronizing the uplink ciphering parameter without interrupting the service.

Abstract: A method, a communication system, and a device for obtaining a connection frame number (CFN) are provided to obtain the CFN under a situation of applying high speed package access (HSPA). The method includes the following steps. A downlink node synchronization request including radio network controller (RNC) time information is sent to a base station through a high-speed downlink shared channel (HS-DSCH) frame protocol (FP). An uplink node synchronization response including base station time information sent from the base station through the HS-DSCH FP is received. A CFN is obtained according to a preset RNC frame number (FN), a preset frame offset, the RNC time information, and the base station time information.