Mitsubishi Denki Kabushiki Kaisha

Norihito Takatori

Seiji Okumura

Kazuma Fukuda

Tomohisa Yamaguchi

Tsugihiko Ohno

In a packet retransmitting system for retransmitting a packet including a sequence number in a packet header, which is lost during packet communication, a transmitting equipment () includes a priority degree information attaching unit () for defining a plurality of priority degrees, setting an importance degree of each of the plurality of priority degrees for a packet, producing priority degree information by using the plurality of priority degrees, and attaching the priority degree information to the packet header included in the packet repeatedly for each of the plurality of packets, a transmitter () for transmitting the plurality of packets, and a retransmitting unit () for receiving a retransmission request packet and retransmitting a packet of which retransmission is requested in the retransmission request packet received. A receiving equipment () includes a receiving unit () for receiving the plurality of packets and a retransmission requesting unit () for extracting a plurality of sequence numbers and a plurality of priority degree information from the packet header, detecting lost packets based on the plurality of sequence numbers and the plurality of priority degree information extracted, detecting an important packet among the lost packets, and requesting retransmission of the packet.

Packet retransmission system, packet transmission device, packet reception device, packet retransmission method, packet transmission method and packet reception method

In a communication system using a terminal connected to a packet network, the invention predicts a future communication state between terminals. This invention may also control congestion by delivering the packet according to the predicted future communication state. A receiving state monitor calculates a moving average of jitter and a packet loss rate based on a packet received by a packet receiver. A controller of a sending bit rate and an encoding rate obtains the moving average of jitter and the packet loss rate predicts a future communication state, and controls the sending bit rate and/or the encoding rate.

Communication system, communication method, transmitting terminal and receiving terminal

This invention relates to a method for providing information by using a contactless IC (integrated circuit) card and a device for providing information. It is an object of this invention to obtain mass data and data created dynamically, and also to solve troublesome work of updating data in the contactless IC card. Dataof location information for accessing dataof external information are stored in a contactless IC card. A devicefor providing information reads the dataof location information and accesses the dataof external information based on the dataof location information read.

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Tokyo, Japan

Norihito Takatori