Fujitsu Corporation

Takeshi Kodama

Tetsumei Tsuruoka

Naoki Oguchi

Ken Yokoyama

A method of an abnormality detection, the method including: calculating an occurrence degree of a packet loss in each of multiple queues on the basis of a first time period in which each of multiple processes that receives a packet is in a waiting state and an arrival frequency of a packet in each of the multiple queues that stores the packets received by the multiple processes; distributing the number of packet losses occurred in a communication device that includes the multiple queues to each of the multiple queues on the basis of the calculated occurrence degree; and determining whether or not an abnormality occurs in each of the multiple processes on the basis of a correspondence relationship between an operation state of each process and the number of packet losses distributed to the queue that corresponds to each process among the multiple queues for each of the multiple processes.

Abnormality detection method and a non-transitory computer-readable storage medium for storing abnormality detection program

A communication device includes a buffer that stores transmission packets. The communication device monitors a free space of the layertransmission buffer. The communication device changes a first window size that is notified from another communication device, to a second window size, based on the free space, and controls an inflow of the transmission packets to the layertransmission buffer, in accordance with the second window size. By providing above-mentioned communication device and a packet control method, a reduction in a throughput caused by overflow in layertransmission buffer is avoided.

Apparatus and method for controlling a window size of packet transmission based on a free space of buffer

A terminal including: an antenna configured to transmit a first random access signal, when the terminal loses a synchronization with a base station, to the base station, and to transmit a second random access signal, when a response signal to the first random access signal is not received by the terminal, to the base station after a period, and a processor configured to obtain a detection result by detecting, when the terminal loses the synchronization with the base station, whether a communication is in progress or not, and to set the period based on the detection result.

Terminal, communication circuit and communication method

A radio communication terminal device includes a storage unit that stores group information indicating a group of frequencies belonging to the same communication carrier, a communication-carrier searching unit that selects one of to-be-selected frequencies, the to-be-selected frequencies being frequencies at which radio waves arrive, and that searches for a communication carrier using the selected frequency on a basis of identification information received at the selected frequency, and a search-execution controlling unit that excludes, from the to-be-selected frequencies, another frequency that belongs to the group information including the selected frequency and that is other than the selected frequency.

Radio communication terminal device and radio communication method

To prevent throughput reduction during handover, the wireless communication system includes a wireless terminal and a plurality of wireless base stations communicating wirelessly with the wireless terminal and performs control to lower the speed at which the wireless terminal communicates with a communication party upon time-out of a timer value generated in accordance with the time required for transmission/reception of a signal between the wireless terminal and a communication party, wherein the wireless base station performs the control to lower the speed of the communication with the wireless terminal so as to increase the timer value when the wireless base station decides execution of the handover of the communication with the wireless terminal to another wireless base station autonomously or in response to a request from the wireless terminal, and subsequently, executes the handover.

Handover method of wireless communication system, and wireless base station and wireless terminal of the same system

A radio communication terminal including: a processor configured to communicate, when a reception quality of a radio signal of the base station is lower than a threshold value and when a first group identification information identifying a base station group to which the base station belongs is not received from the base station, to each of neighbor base stations sequentially in an intermittent reception period, to specify a specified neighbor base station of the neighbor base stations, the specified neighbor base station belonging to the base station group, based on whether a second group identification information is received from each of the neighbor base stations or not and based on the first group identification and the second group identification are same or not, to select the specified base station preferentially to which the terminal is to hand over, among the neighbor base stations.

Communication terminal device and communication control method

A wireless communication apparatus including a wireless communication interface configured to receive radio waves, and a processor configured to measure radio-wave qualities of the radio waves from a plurality of base stations in a periodic measurement period, to divide one measurement period out of the periodic measurement period, and to measure radio-wave qualities of the corresponding measurement-target base stations, to determine a base station to be excluded from the measurement-target base stations in a next measurement period in the periodic measurement period on the basis of the radio-wave qualities, and to allocate the measurement time period that has been allocated to the base station to be excluded in a measurement period to a measurement-target base station in the next measurement period.

Wireless communication apparatus and scan control method

A mobile station for wirelessly communicating with a base station, the mobile station including a storage unit for storing determination information for determining whether or not an application that requires wireless communication is being executed and operation information defining whether or not the application maintains a logical connection when the application is out-of-service for each application; and a processor for, when detecting out-of-service state, determining an application being executed on the basis of the determination information, determining whether or not the application being executed maintains the logical connection on the basis of the operation information, and when determining that the application maintains the logical connection, trying to wirelessly connect to the base station.

Mobile station and communication control method

A virtual interface having a global address of a physical interface on an Internet side of a gateway is provided in a terminal. An application unit of the terminal transmits a packet to the Internet using the virtual interface. The packet is transferred to the gateway through a downlink transfer path. The gateway transmits the packet from the physical interface on the Internet side to the Internet.

Network system, terminal, and gateway

A mobile station includes an intermittent communication managing unit that manages a communication period for communicating with a first base station and a non-communication period for not communicating with the first base station, and a scan period setting unit that shifts and sets a scan period to reduce an overlap period with the communication period. The scan period, during which a scanning process for obtaining a condition of radio waves from a second base station can be executed, overlaps a plurality of the communication periods. Moreover, the mobile station includes a scan processor that executes the scanning process during the scan period.

Mobile station and base stations

A disclosed mobile station includes a switching unit for, when the mobile station is in a communication area of a first base station (BS), switching a reception operation to receive a signal transmitted from the first BS during a first period and not to receive the signal during a second period; an acquiring unit for acquiring from a second BS information on a transmission timing of a communication parameter if the mobile station is yet to receive neighboring BS information from the first BS; a query unit for querying the first BS as to whether there are data directed to the mobile station; and a receiving unit for receiving the communication parameter from the second BS according to the transmission timing if the acquired information indicates that the transmission timing is to occur during the first period and a result of the query indicates that there are no data.

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Kawasaki, Japan

Takeshi Kodama