Abstract: A radio communication apparatus for performing extended discontinuous reception (eDRX) to a network including a base station, the apparatus including a configuration configured to transmit a TAU Request, perform a transmission processing of the TAU Request, set an eDRX period included in the TAU Request to a first period and transmit the TAU Request when a probability of data reception after transmission of the TAU Request is low, set the eDRX period included in the TAU Request to a second period and transmit the TAU Request when the probability of data reception after transmission of the TAU Request is high, and the second period is longer than the first period.

Abstract: A radio communication apparatus for performing extended discontinuous reception (eDRX) to a network including a base station, the apparatus including a configuration configured to transmit a TAU Request, perform a transmission processing of the TAU Request, set an eDRX period included in the TAU Request to a first period and transmit the TAU Request when a probability of data reception after transmission of the TAU Request is low, set the eDRX period included in the TAU Request to a second period and transmit the TAU Request when the probability of data reception after transmission of the TAU Request is high, and the second period is longer than the first period.

Abstract: A radio communication system includes a first radio base station corresponding to a first radio communication scheme and a second radio base station corresponding to a second radio communication scheme. The first radio base station transmits a first switching request notification for requesting switching of a connection to the second radio base station to a radio terminal connected to the first radio base station when emergency information associated with an emergency situation from an upper network has been received. The radio terminal transmits, to the second radio base station, a connection request notification for requesting a connection to the second radio base station when the first switching request notification has been received.

Abstract: A wireless communication apparatus is provided with a wireless communication unit (31, 32, 34) for performing wireless communication by connecting to a first wireless communication network 15 and a second wireless communication network 16, an execution unit 33 of an application (application) for real-time communication, a jitter buffer 47 for absorbing jitter of packets of the application, a communication quality obtain unit 35 for obtaining communication quality of a wireless link in the first wireless communication network 15, a handover control unit 36 for starting handover from the first wireless communication network 15 to the second wireless communication network 16 based on the communication quality obtained, and a control unit 33 for controlling a reproduction speed of the application based on an accumulated packet amount in the jitter buffer 47 when a reception interval of packet received after completion of handover is equal to or over a predetermined value.

Abstract: A wireless communication apparatus capable of using a plurality of different wireless communication systems includes a receiving unit (110) for receiving an inquiry message inquiring whether possible to respond to a call establishing message to be transmitted later from a calling side by selecting a wireless communication system satisfying a condition desired by the calling side, a transmitting unit (110) for determining whether possible to respond to the call establishing message by selecting the wireless communication system satisfying the condition among the plurality of wireless communication systems (COM1, COM2 and COM3) based on the inquiry message received and for transmitting a response message indicating a result of the determination to the calling side, and a control unit (120) for controlling to respond to the call establishing message transmitted later by the calling side by selecting the wireless communication system based on the result of the determination.

Abstract: A reproduction speed of an application being executed is controlled with changing an upper limit of accumulation of a jitter buffer based on a radio state during communication by a first wireless communication network. If it is determined to start handover preparation from the first wireless communication network to a second wireless communication network, a preparation time before handover and an absolute delay time of each of the first wireless communication network and the second wireless communication network are obtained from the handover control unit. Based on such information obtained and a data amount in a jitter buffer at a time when it is determined to start the handover preparation, the reproduction speed of the application being executed is controlled to be slowed down. Thereby, it is possible to perform handover to a different wireless communication network without deteriorating reproduction quality and real-time property.

Abstract: A radio communication system includes a first radio base station corresponding to a first radio communication scheme and a second radio base station corresponding to a second radio communication scheme. The first radio base station transmits a first switching request notification for requesting switching of a connection to the second radio base station to a radio terminal connected to the first radio base station when emergency information associated with an emergency situation from an upper network has been received. The radio terminal transmits, to the second radio base station, a connection request notification for requesting a connection to the second radio base station when the first switching request notification has been received.

Abstract: In order to perform handover from a first wireless communication network 15 to a second wireless communication network 16, a preparation time for handover, communication quality after scheduled handover execution, and a delay time of each of the first wireless communication network and the second wireless communication network are obtained by a handover control unit 36 in advance. Based on such information obtained and data amount in a jitter buffer 47 at a time of determination to start preparation for handover, a reproduction speed of an application being executed is controlled. Thereby, it is possible to perform handover to a different wireless communication network without deteriorating the reproduction quality and real-time property.

Abstract: There is a problem that, if a silent period is generated to a real-time application such as VoIP due to handover using BBM method, a user has a sense of anxiety and misunderstands that communication is completely disconnected. If the silent period is generated to the real-time application such as VoIP due to packet loss at handover, a terminal activates handover alarm (beep sound, for example), indicating that handover is in progress, during the silent period. Thereby, it notifies the user that the silent period is caused by handover and prevents user's misunderstanding that communication is completely disconnected.

Abstract: In order to perform handover from a first wireless communication network to a second wireless communication network, a handover control unit obtains a handover preparation time to handover, and by receiving data via the first wireless communication network and the second wireless communication network separately obtains a delay time difference between the networks based on reception times of the same data. Based on such information obtained and an amount of the data in a jitter buffer at a point to determine to start handover preparation, the handover control unit controls a reproduction speed of an application being executed. Thereby, it is possible to perform handover to a different wireless communication network without deteriorating reproduction quality and real-time property and causing packet loss.

Abstract: In order to perform handover from a first wireless communication network to a second wireless communication network, a handover control unit obtains a handover preparation time Tb to handover, respective delay times Tddn1 and Tddn2 of the wireless communication networks, and the jitter buffer monitoring unit monitors a packet amount Tc in the jitter buffer and a type of the packet to be reproduced. The application is controlled, in case of voice packets, so as to reproduce the voice packets at a reproduction speed calculated based on the handover preparation time Tb, the delay times Tddn1 and Tddn2, the packet amount Tc in the jitter buffer and an elapsed time after start of handover preparation and, in case of non-voice packets, so as to control the non-voice packets at a reproduction speed in accordance with a silent period thereof. Thereby, it is possible to perform handover to a different wireless communication network without deteriorating reproduction quality and real-time property.

Abstract: An origination terminal UA100 according to the present invention is provided with a screen state memory unit 500 for storing a screen state of an information display unit 360 at transmission of a call request including information on communication on a desired network and an initiation state of an application corresponding to the screen state and a control unit 320 for controlling the information display unit 360, when receiving a call enable notification in response to a call enable notification request transmitted after cancellation of a call from a destination terminal UA200, which becomes able to use the desired network, to display the screen state stored in the screen state memory unit 500 and, when detecting a call instruction in the screen state, an application corresponding to the call instruction to send a call.

Abstract: An origination terminal in accordance with the present invention is provided with a control unit for controlling, when receiving information indicating that a destination terminal uses a network different from a network desired by an originator, so as to transmit a call enable notification request requesting the destination terminal, when the destination terminal can connect to the network desired by the originator, to transmit a call enable notification notifying the originator accordingly. The destination terminal in accordance with the present invention is provided with a control unit for controlling, when receiving the call enable notification request from the origination terminal, so as to transmit the call enable notification when the destination terminal can connect to the network desired by the originator.

Abstract: A destination terminal UA200 in accordance with the present invention, which is a wireless communication apparatus capable of using a plurality of different wireless communication systems, is provided with a control unit 320 for determining, in a case where the destination terminal UA200 receives a call enable notification request from an origination terminal UA100, whether a desired network satisfies a condition to transmit the call enable notification based on a condition of the desired network and a required bandwidth for a desired application when the destination terminal UA200 becomes connectable to the desired network, and for controlling so as to transmit the call enable notification when the desired network satisfies the condition to transmit the call enable notification, while controlling so as to transmit a condition deterioration notification when the desired network does not satisfy the condition.

Abstract: An origination terminal UA100 in accordance with the present invention is provided with a control unit 320 for controlling, when receiving information indicating that a destination terminal uses a network different from a network desired by an originator, so as to transmit a call enable notification request requesting the destination terminal, when the destination terminal UA200 can connect to the network desired by the originator, to transmit a call enable notification notifying the originator accordingly. The destination terminal UA200 in accordance with the present invention is provided with a control unit 320 for controlling, when receiving the call enable notification request from the origination terminal UA100, so as to transmit the call enable notification when the destination terminal UA200 can connect to the network desired by the originator.

Abstract: There is a problem that, if a silent period is generated to a real-time application such as VoIP due to handover using BBM method, a user has a sense of anxiety and misunderstands that communication is completely disconnected. If the silent period is generated to the real-time application such as VoIP due to packet loss at handover, a terminal activates handover alarm (beep sound, for example), indicating that handover is in progress, during the silent period. Thereby, it notifies the user that the silent period is caused by handover and prevents user's misunderstanding that communication is completely disconnected.

Abstract: In order to perform handover from a first wireless communication network to a second wireless communication network, a handover control unit obtains a handover preparation time to handover, and by receiving data via the first wireless communication network and the second wireless communication network separately obtains a delay time difference between the networks based on reception times of the same data. Based on such information obtained and an amount of the data in a jitter buffer at a point to determine to start handover preparation, the handover control unit controls a reproduction speed of an application being executed. Thereby, it is possible to perform handover to a different wireless communication network without deteriorating reproduction quality and real-time property and causing packet loss.

Abstract: In order to perform handover from a first wireless communication network to a second wireless communication network, when it is determined to start preparing for handover from the first wireless communication network to the second wireless communication network, data are transmitted via the first wireless communication network and simultaneously accumulated for a predetermined period. The accumulated data are transmitted via the second wireless communication network after handover. It thus enables to transmit the data in the predetermined period, which are expected to be lost because of handover, while accumulating the data and to transmit accumulated data after handover. Thereby, it is possible to provide a wireless communication apparatus and a communication apparatus capable of performing handover to a different wireless communication network without causing packet loss and thus maintaining stable reproduction quality and real-time property all the time.

Abstract: A reproduction speed of an application being executed is controlled with changing an upper limit of accumulation of a jitter buffer based on a radio state during communication by a first wireless communication network. If it is determined to start handover preparation from the first wireless communication network to a second wireless communication network, a preparation time before handover and an absolute delay time of each of the first wireless communication network and the second wireless communication network are obtained from the handover control unit. Based on such information obtained and a data amount in a jitter buffer at a time when it is determined to start the handover preparation, the reproduction speed of the application being executed is controlled to be slowed down. Thereby, it is possible to perform handover to a different wireless communication network without deteriorating reproduction quality and real-time property.

Abstract: In order to perform handover from a first wireless communication network to a second wireless communication network, a handover control unit obtains a handover preparation time Tb to handover, respective delay times Tddn1 and Tddn2 of the wireless communication networks, and the jitter buffer monitoring unit monitors a packet amount Tc in the jitter buffer and a type of the packet to be reproduced. The application is controlled, in case of voice packets, so as to reproduce the voice packets at a reproduction speed calculated based on the handover preparation time Tb, the delay times Tddn1 and Tddn2, the packet amount Tc in the jitter buffer and an elapsed time after start of handover preparation and, in case of non-voice packets, so as to control the non-voice packets at a reproduction speed in accordance with a silent period thereof. Thereby, it is possible to perform handover to a different wireless communication network without deteriorating reproduction quality and real-time property.