Abstract: A communication apparatus includes a decipher deciphering received ciphered data, a first processor configured to generate, when receiving deciphered data for which the ciphered data is deciphered, a header of a first protocol including the deciphered data in a payload and an addition value for which the deciphered data is added in a predetermined size unit, a packet including the deciphered data, the header of the first protocol, and a header of a second protocol and a header of a third protocol, a second processor configured to calculate a checksum value set to the header of the second protocol using the addition value and a transmitter configured to transmit the packet to which the checksum value is set.

Abstract: A communication device includes, a plurality of authentication generation processing units, which are respectively associated with different sequence number groups each including successive sequence numbers and which execute, in parallel, authentication generation processes for generating authentication information included in the packets based on sequence numbers allocated to the packets, a transmitting unit which transmits packets including the allocated sequence numbers to another communication device in an order in which authentication generation processes by the plurality of authentication generation processing units are completed, a receiving unit which receives a packet from the other communication device, and an authentication processing unit which executes a first authentication process in which the reception packet is authenticated based on a relationship between a sequence number of the reception packet and a sequence number of a preceding reception packet.

Abstract: A packet transmission apparatus verifies a sequence number of each received packet using an anti-replay window. Upon detecting a suspected packet with a sequence number exceeding a highest sequence number set in the anti-replay window, an inquiry transmitting unit transmits a highest sequence number inquiry to an opposing apparatus. An anti-replay control unit drops the suspected packet when the sequence number of the suspected packet is more than a highest sequence number acquired from a response of the opposing apparatus in reply to the highest sequence number inquiry.

Abstract: When being triggered by a call setting request that has been made, dummy information that is different from information to be transmitted and is information used for creating a path on which encrypted communication is to be performed is generated. The path on which the encrypted communication is to be performed is established by using the generated dummy information. A responding process of responding to the call setting request is performed after the path on which the encrypted communication is to be performed has been established. Thus, in the case where information that is obtained after the responding process of responding to the call setting request is encrypted and transmitted, it is possible to transmit the information while maintaining the real-time characteristics of the information to be transmitted.

Abstract: A packet is transmitted from a transmitting device to an active communication device which transmits a reception history identifying the received packets to the transmitting device. The transmitting device transmits an active-mode request message to a standby communication device when having failed to receive the reception history from the active communication device within a predetermined time period. Then, the standby communication device becomes a new active communication device, and the active communication device becomes an old active communication device. The new active communication device transmits to the transmitting device a switching request message for switching a destination of the packet from the old active communication device to the new active communication device.

Abstract: A mobile communication system has a mobile terminal, basestations, and a Radio Network Controller (RNC). In the case where drop of a frame occurs during data communication in Iub/Iur (between the basestations and the RNC), the RNC executes retransmission of an EDCH FP frame between the RNC and the basestations by transmitting a TN frame to the basestations to repair the drop of the frame without executing retransmission with the terminal device.

Abstract: A packet is transmitted from a transmitting device to an active communication device which transmits a reception history identifying the received packets to the transmitting device. The transmitting device transmits an active-mode request message to a standby communication device when having failed to receive the reception history from the active communication device within a predetermined time period. Then, the standby communication device becomes a new active communication device, and the active communication device becomes an old active communication device. The new active communication device transmits to the transmitting device a switching request message for switching a destination of the packet from the old active communication device to the new active communication device.

Abstract: A mobile communication system has a mobile terminal, basestations, and a Radio Network Controller (RNC). In the case where drop of a frame occurs during data communication in Iub/Iur (between the basestations and the RNC), the RNC executes retransmission of an EDCH FP frame between the RNC and the basestations by transmitting a TN frame to the basestations to repair the drop of the frame without executing retransmission with the terminal device.

Abstract: When being triggered by a call setting request that has been made, dummy information that is different from information to be transmitted and is information used for creating a path on which encrypted communication is to be performed is generated. The path on which the encrypted communication is to be performed is established by using the generated dummy information. A responding process of responding to the call setting request is performed after the path on which the encrypted communication is to be performed has been established. Thus, in the case where information that is obtained after the responding process of responding to the call setting request is encrypted and transmitted, it is possible to transmit the information while maintaining the real-time characteristics of the information to be transmitted.

Abstract: A first apparatus includes a sending unit which attaches a sequence number which is numbered for each priority of QoS set in a first packet, the sequence number is numbered for each priority of QoS set in the first packet, and sends the first packet with the sequence number. A second apparatus includes a storage unit which stores, for each priority, a history of sequence numbers attached to packets received, a determining unit which receives the first packet from the first apparatus, identifies the sequence number of the first packet, and determines whether the first packet has been previously received by comparing the identified sequence number with the history of sequence numbers according to the priority of QoS set in the first packet stored in the storage unit, and a unit which discards, when the determining unit determines the first packet has been previously received, the first packet.