Nec Corporation

Takashi Oshiba

Yoshiaki Nishikawa

Kazuaki Nakajima

Katsuhiro Ochiai

Toru Osuga

Kozo Satoda

A receiver includes a reception part, a determination part, and an estimation part. The reception part receives a packet train(s) formed by a plurality of packets transmitted from a transmitter. The determination part determines whether bandwidth limitation is executed in a network based on the received packet train(s). The estimation part selects a method for estimating an available bandwidth in the network based on whether or not the bandwidth limitation is executed and estimates the available bandwidth in the network in accordance with the selected method.

Receiver, communication system, available bandwidth estimation method, and storage medium in which program is stored

In order to enable to reduce a communication load while maintaining estimation accuracy of available bandwidth estimation being high, a transmission method includes: transmitting estimation packets, a packet size of each of which successively increases, to an available bandwidth estimation device at equal intervals, and, when receiving a signal indicating that a reception interval between the estimation packets at the available bandwidth estimation device starts to increase, stopping the transmission of the estimation packets.

Transmission device, available bandwidth estimation device, available bandwidth estimation system, method, and recording medium

Failure to identify an accurate rising position of a queueing delay alone has led to the inability to ensure estimation precision. An available bandwidth estimation method comprises: transmitting a packet train constituted by packet pairs arranged at equal intervals, each of the packet pairs comprising two packets of the same size arranged at a zero transmission interval, with the packet size of the packet train increasing at a constant rate; receiving the packet train; calculating an observation delay of the packets included in the received packet train; calculating a serialization delay on the basis of the reception interval between the two packets constituting each packet pair included in the received packet train; removing the calculated serialization delay from the calculated observation delay, thereby calculating a queueing delay; and estimating an available bandwidth on the basis of the calculated queueing delay.

Available bandwidth estimation system, available bandwidth estimation method, reception apparatus, and reception apparatus program storage medium

Provided is a communication apparatus including: data transmission-reception unit that is communicably connected to at least one terminal apparatus via a communication line; and bandwidth estimation unit. The bandwidth estimation unit is configured to generate particular information to be used to estimate an available bandwidth on the communication line, determine whether to transmit in series or in parallel the particular information for a particular one of the terminal apparatuses and the particular information for another one of the terminal apparatuses, and estimate the available bandwidth of the communication line between the communication apparatus and terminal apparatuses, by transmitting, based at least part on the determination, the particular information for the particular terminal apparatus and the particular information for the another terminal apparatus, with uses of the data transmission-reception unit.

Communication device, network available bandwidth estimation method in communication device, and storage medium on which network available bandwidth estimation program has been recorded

The available bandwidth estimating system is provided with a transmitting device and a receiving device, and estimates available bandwidth for a network that connects the transmitting device and the receiving device. The transmitting device is provided with a packet transmission means that transmits a packet train, comprising a given number of packets with packet sizes which are incremented by a certain increment, so that each packet is at even intervals. The receiving device is equipped with a receiving means that receives the packet train from the packet transmission means and calculates the cumulative queuing delay for the packets included in the packet train, and an available bandwidth calculating means that calculates an estimated value for available bandwidth by detecting a point of variation in the overall change of the cumulative queuing delay.

Available bandwidth estimating system, method, and program

A first terminalincludes: a local terminal transmission rate acquisition unitfor acquiring a transmission rate of an application in the first terminal; a search range control unitfor deciding an upper limit of a search range of an available bandwidth of a communication line, using the transmission rate; and a probe packet transmission unitfor transmitting a probe packet to a second terminalin a bandwidth less than or equal to the upper limit. The second terminalincludes: a probe packet receiving unitfor receiving the probe packet; and an available bandwidth estimation unitfor estimating the available bandwidth based on the received probe packet.

Available bandwidth search range control method and available bandwidth search range control system

An order of terminal devices that are destinations of a measurement packet train to be transmitted is instructed to each of a plurality of terminal devices connected together via a network (step S). The measurement packet train is transmitted from each of the plurality of terminal devices to a destination terminal device in accordance with the instructed order (step S). An available bandwidth in a path from an originator of the measurement packet train to the destination is calculated based on a receiving status of the measurement packet train at the destination terminal device (step S).

Usable bandwidth measurement method, usable bandwidth measurement system, terminal device, and computer-readable recording medium

A packet generation unit () generates a predetermined number of measurement packets at predetermined transmission intervals that increase in equal increments, and a transmission/reception unit () transmits the measurement packets to a reception device () in accordance with control performed by a transmission control unit (). A calculation unit () calculates an available bandwidth in accordance with the reception intervals of the measurement packets received by a transmission/reception unit (), and the transmission/reception unit () transmits the available bandwidth to a transmission device (). A resolution alteration unit () determines, in accordance with the available bandwidth received by the transmission/reception unit (), whether or not to change the measurement resolution. A size alteration unit () changes the minimum packet size, maximum packet size and packet size incremental increase amount when the resolution alteration unit () determines that the measurement resolution is to be changed. The packet generation unit () newly generates measurement packets in accordance with the changed values.

Available bandwidth measurement system, transmission device, available bandwidth measurement method and recording medium

A contents playback apparatus and the like are provided which allow a user to promptly designate a desired portion when displaying a part of a content in an expanded manner, and are thus excellent in operability. A contents playback apparatus includes an associating unit and a playback unit. The associating unit generates association information for a plurality of characteristic portions contained in a content by referring to priority orders of the respective characteristic portions relative to each other, the association information associating each of the characteristic portions individually with a predetermined operation key of an input device included in the apparatus in accordance with the priority orders. The playback unit plays back, in response to detecting an operation of an operation key during display of the content, the characteristic portion corresponding to the operation key in an expanded display mode, in accordance with the association information.

Contents playback apparatus, contents playback method, and computer program

A call interlocking system according to the present invention includes a plurality of in-house control apparatuses each including, data relay means for relaying communication data between a telephone and a call control server and communication data between an information display terminal and an information providing server respectively, and interlocking means for determining whether or not it is possible to interlock a telephone call performed by the telephone with a service that the information display terminal requests to start, and for notifying, when the interlocking means determines that the interlocking is possible, a start request of the service including information for specifying the telephone call to the information providing server, and an information providing server that interlocks the service with the telephone call and provides the interlocked service based on the start request of the service notified from the in-house control apparatus.

Call interlocking system, in-house control apparatus, and call interlocking method

To provide a pairing system which requires no special hardware and is capable of easily pairing terminals intended by a user. A pairing management device includes a pairing control module which receives pairing requests from communication terminals and data terminals, and generates tentative pairs from the communication terminals and the data terminals which transmitted the pairing request, and a confirmation data control module which allots and transmits pair confirmation data which corresponds on one-on-one basis to the communication terminals and the data terminals forming the tentative pairs, and allows the pairing control module to update the tentative pairs to final pairs when the pairing control module receives pair alteration data corresponding to the pair confirmation data from the communication terminals or the data terminals.

Pairing system, pairing management device, pairing method, and program

Disclosed is a pairing apparatus. When a pairing start request is received from a first terminal and a second terminal, in response to the request, one piece of identifier data, which is used for displaying identifiers on displays of said first terminal and said second terminal, is transmitted to the first terminal, and one or more pieces of the identifier data including the one piece of the identifier data transmitted to the first terminal are transmitted to the second terminal. Thereafter, when one identifier selected from one or more identifiers transmitted to the second terminal is received from the second terminal, it is determined whether or not the identifier received from the second terminal is identical to the one identifier transmitted to the first terminal, and when the determination is yes, the first terminal and the second terminal are paired.

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Tokyo, Japan

Takashi Oshiba