Fujitsu Corporation

Tetsumei Tsuruoka

Naoki Oguchi

Yuji Kojima

Makoto Kubota

Takeshi Kodama

Yasuyuki Umezaki

Yoshitomo Shimozono

Yuji Nomura

Toshiyuki Sudo

Kenichi Abiru

Kensaku Amou

Satoshi Soejima

A disclosed load estimation method includes: collecting run information of a processor being executing a predetermined program; specifying execution status of the processor based on the collected run information; and estimating a load of the predetermined program based on a result of comparison between the execution status of the processor and execution characteristics of the processor. Each of the execution characteristics is stored in association with a load level of the predetermined program.

Method and apparatus for load estimation

A measurement apparatus calculates a rate based on a time base of a second communications apparatus by dividing a total data amount arriving between two arbitrary response messages corresponding to transmission data, by a difference in transmission time information of the response messages. The measurement apparatus calculates a time conversion factor between a first communications apparatus and the second communications apparatus. The measurement apparatus calculates an arrival rate of the transmission data based on a time base of the first communications apparatus, by multiplying the calculated rate by the calculated time conversion factor.

Measurement apparatus, communications apparatus, and relay apparatus

A communication device receives a first packet at a first receipt time, receives a plurality of packets after the first receipt time, the plurality of packets including a second packet, a third packet and a fourth packet, the second packet being received next to the first packet at a second receipt time, an interval between the first receipt time and the second receipt time exceeding a first time period, the plurality of packets being received at an interval shorter than the first time period, the third packet being received before an Nth packet among the plurality of packets, the fourth packet being any of the Nth and following packets among the plurality of packets, transmits a first acknowledgement for the third packet, hold a second acknowledgement for the fourth packet for a second time period, and transmits the second acknowledgement after holding the second acknowledgement for the second time period.

Communication device, relay device, and communication method for a plurality of packets

A communication node disposed on a packet transfer path through which packets flow between an end of a transmitting side and an end of a receiving side according to a specific protocol under which flow control and congestion control using a window size are performed, the communication node including a communication interface configured to perform processing for receiving a packet from a link on the transfer path and processing for transmitting a packet to the link, a storage device configured to store a queue in which a packet in accordance with the specific protocol received from the link or a packet in accordance with the specific protocol transmitted to the link is temporarily accumulated, and a controller configured to adjust a period of time for retaining the packet accumulated in the queue on the basis of the current bandwidth of the link on the receiving side.

Communication node

A communication terminal is configured to control a packet transmission amount based on the number of packets transmittable to a destination device without receiving an acknowledgement signal (ACK) transmitted from the destination device to indicate its acceptance for the packets transmitted from the communication terminal, the communication terminal includes a processor configured to execute a procedure, the procedure includes determining whether it is appropriate timing for packet transmission, based on an amount of tokens which are accumulated according to a target transmission rate, the transmission timing including timing when receiving the ACK and timing when a timer value updated at each timing of the packet transmission executed in the communication terminal expires, and transmitting a packet at the transmission timing in which it is determined that transmission is appropriate.

Communication terminal and 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 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 wireless terminal for transmitting data to a base station with placing the data on a plurality of subcarriers, the wireless terminal includes: an antenna; and a processor configured for controlling the antenna to transmit, to the base station, a request signal for requesting an access right with placing the request signal on a predetermined number of subcarriers; and controlling the antenna to transmit, to the base station, a request message for requesting a communication resource being transmitted by subcarriers whose number is less than the predetermined number, to use the access right assigned by the base station with respect to the request signal when the wireless terminal has transmission data; wherein the processor is configured to control the antenna to transmit the request message to the base station when the level of communication with the base station is lower than a threshold value.

Wireless terminal

A radio communication apparatus including: a radio interface; and a processor configured to control the radio interface to transmit a Ranging signal to a base station and to control a transmission power level of the Ranging signal; when the processor controls the radio interface to retransmit the Ranging signal, the retransmission includes a first phase and a second phase, the first phase in which the processor controls the radio interface to retransmit the Ranging signal at substantially a same transmission power level as at the time of initial transmission, or performs substantially a same calculation as that made at the time of the initial transmission of the Ranging signal and retransmits the Ranging signal at the calculated transmission power level, the second phase in which the processor increases the transmission power level and retransmits the Ranging signal at the increased transmission power level.

Radio communication apparatus and transmission power control method having first retransmission phase and second retransmission phase

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 wireless communication terminal apparatus communicates with a wireless base station wirelessly. The wireless communication terminal apparatus includes a wireless communication unit and a control unit. The wireless communication unit communicates wirelessly. The control unit transmits a search request, in which search duration for searching a wireless base station is included, from the wireless communication unit to a wireless base station during connection, and when a search response is received in the wireless communication unit from the wireless base station during connection, suspends at least a transmitter in the transmitter and a receiver of the wireless communication unit in all or a part of the search duration.

Apparatus, module and method used for wireless communication

A communication apparatus includes a controller configured to control transmission of a bandwidth request message, the transmission being triggered by a detection of connection establishment between the communication apparatus and a destination apparatus in a layer that is higher than a media-access control layer; and a transmitter configured to transmit the bandwidth request message in accordance with a control of the controller.

Communication apparatus, communication interface module, and communication method

A radio terminal includes a first part that has a first gain switchable between first and second levels, a second part that continuously controls a second gain, and a control part. A first range of the combined gain of the first and second gains obtained by the second part with the first gain set at the first level and a second range of the combined gain obtained by the second part with the first gain set at the second level have at least an overlap. The control part switches the first gain from one to the other of the first and second levels if the combined gain is within the overlap and a change in the combined gain exceeds a predetermined value, or if the combined gain is within the overlap and the radio terminal is in a period of no transmission or reception in intermittent transmission or reception.

Radio terminal and transmission power control method

At the time of exchanging routing information of a remote site, it is examined whether there is duplicated routing information, and when the duplicated routing information exists, an address conversion rule is generated. With this, when performing communication, address conversion is performed only for the communication to a site having a duplicated network address. In case of communication to a site having no duplicated network address, by performing IP communication intact, it becomes possible to omit unnecessary address conversion processing in a gateway. Also, when there is a duplicated address, by assigning a new network address which is not used in a site under a gateway to the duplicated address included in the routing information, and distributing the newly assigned address, it becomes possible to transmit a packet to a gateway appropriate to each destination, when there are a plurality of gateways in a subnet.

Packet relaying method and packet relaying system

A community control server stores in a community defining table, data of a correspondence between Interior Gateway Protocol (IGP) routers that are connected to a community and another community. The community control server collects prefix data that is included in routing information that is received by the IGP routers and identification data of the IGP routers. Based on the community defining table and the identification data, the community control server detects a community corresponding to a prefix. Upon receiving data of whether to transmit the routing information in the form of the permission to distribute them between communities, based on data of the community the community control server determines the prefix corresponding to the source community and transmits the prefix data to the IGP routers.

Growing community of inventors

Kawasaki, Japan

Tetsumei Tsuruoka