Sanyo Electric Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Hera Wireless S.a.

Panasonic Corporation

Kyocera Corporation

Makoto Nagai

Ken Nakaoka

Yoshiharu Doi

Kiyoshige Ito

Keisuke Higuchi

Noriaki Kojima

Yoshio Yuse

Masaya Okumura

Yumi Okamura

Yuki Yorifuji

Fuminori Takama

Masafumi Furuke

A control information extraction unit receives information on a frame that contains at least a plurality slots from an access control apparatus for controlling communications between radio apparatuses. The control information extraction unit generates a frame that contains at least a plurality of slots in such a manner as to synchronize with the frame corresponding to the received information. An estimation unit estimates empty slots in the plurality of slots generated. A selection unit selects, at random, at least one of the estimated. A modem unit and the like broadcast data using the selected slot.

Broadcasting method for sending signal containing predetermined information and radio apparatus

An RF unit and a modem unit receive a packet signal, containing information regarding a frame construction, which is transmitted from a base station apparatus in a first period of a frame at least including first periods and second periods. An extraction unit identifies the second period in the frame, based on the received packet signal. A setting unit sets a waiting time period in the identified second period. A carrier sensing unit carries out carrier sensing over the waiting time period set by the setting unit. The modem unit and the RF unit broadcast the packet signal based on a result of the carrier sensing.

Terminal apparatus transmitting signal containing predetermined information

An extracting unit detects movement from a first area to a second area, the first area and the second area defined as areas having different priorities. When the extracting unit detects the movement, this changes a communication process defined in the first area to the communication process defined in the second area. A notifying unit notifies that the area changed when the movement is detected. Herein, the priority of the first area and the priority of the second area are defined according to importance of a signal, which should be broadcasted from a processing unit.

Radio apparatus transmitting or receiving a signal including predetermined information

It is specified that a frame containing at least the plurality of slots is repeated. A detecting unit detects a slot usable in the communications between terminal apparatuses, from among a plurality of slots. A modem unit and an RF unit broadcast the information on the detected slot. A power measuring unit in the detecting unit measures the respective received powers of the plurality of slots, and an empty slot identifying unit identifies a slot whose received power is less than a threshold value.

Broadcasting method and access control apparatus

An RF unit broadcasts a packet signal, and receives a packet signal broadcasted from another terminal apparatus. A processing unit generates a packet signal to be broadcasted and processes a received packet signal. A mode setting unit selects a first mode or a second mode as a broadcast mode. The RF unit sets first transmission power in case of the first mode and sets second transmission power lower than the first transmission power in case of the second mode. The processing unit includes an identification number uniquely allocated to the present terminal apparatus in a packet signal in case of the first mode, and includes an identification number commonly allocated to a system of terminal-to-terminal communication in a packet signal in case of the second mode.

Terminal apparatus for transmitting or receiving a signal including predetermined information

A map data storage unit holds map data in which a road ID is allocated, as identification information, to every preset section of at least part of roads. A traffic jam determination unit determines whether the section corresponding to every road ID is congested. A transmission unit performs broadcast transmission of vehicle data including a road ID and the traveling speed of a vehicle from the vehicle traveling in each section of a road. At the time, the transmission unit forms a frame in which the received vehicle data of other vehicle and the vehicle data of a driver's vehicle are combined. An information compressing unit compresses an amount of data by deleting the traveling speed from the frame with respect to a section that has been determined not to be congested by the traffic jam determination unit.

Terminal apparatus mounted on a vehicle to perform vehicle-to-vehicle communication

A control information extraction unit receives information on a frame that contains at least a plurality slots from an access control apparatus for controlling communications between radio apparatuses. The control information extraction unit generates a frame that contains at least a plurality of slots in such a manner as to synchronize with the frame corresponding to the received information. An estimation unit () estimates empty slots in the plurality of slots generated. A selection unit selects, at random, at least one of the estimated. A modem unit and the like broadcast data using the selected slot.

A modem unit receives a signal broadcasted by a base station apparatus. A storage unit extracts information included in the received signal and stores the extracted information. A detection unit detects a fact that the signal broadcasted by the base station apparatus is not received. A generation unit measures a period of time starting when the storage unit has stored the information. When the detection unit detects the fact and when the measured period of time is shorter than a threshold, the generation unit broadcasts a signal including the information stored in the storage unit.

A data processing section selects either base station mode or terminal mode and executes communication. A control section controls operations relating to the base station mode and the terminal mode. A receiving section receives an instruction to switch to the base station mode from other wireless device set in the base station mode, in the case where communication is set in the terminal mode. An AP switching section switches to the base station mode in accordance with the instruction. An instructing section instructs other wireless devices set in the terminal mode to switch to the base station mode, after a predetermined period is passed from the time when the mode is switched to the base station mode. An STA switching section switches to the terminal mode after giving the instruction.

Wireless device capable of multiple access to other wireless devices

A processing unit sets the time interval before packet signals are broadcast, using a carrier sense multiple access (CSMA) scheme. A modem unit and an RF unit broadcasts the packet signals at the time intervals set by the processing unit. The RF unit and the modem unit receive a control signal broadcast from an access control apparatus at a predetermined frequency. The processing unit sets the time interval, during which the control signal is receivable, to a time length shorter than the time interval for the remaining cases.

Broadcasting method and radio apparatus

A data processing unit selects either one of a base station mode and a terminal mode so as to perform communications using packet signals. The base station mode is a mode in which a packet signal, containing data indicating that an initial source and a final destination are not its own radio apparatus, is to be communicated; the terminal mode is a mode in which a packet signal, containing data indicating that the initial source or the final destination is its own radio apparatus, is to be communicated. A control unit starts the radio apparatus by setting the data processing unit in the terminal mode. When a packet signal, which has been transmitted from another radio apparatus and which contains broadcast information, has not been received before a certain period of time elapses after the start, the control unit switches the mode of the data processing unit to the base station mode.

Radio apparatus which communicates with other radio apparatuses and communication system

A base station apparatus includes a measurement unit, a derivation unit and an allocation unit. A base station apparatus allocates at least one subcarrier block, in a frequency band containing a plurality of subcarrier blocks composed of a plurality of subcarriers, to a terminal apparatus. The measurement unit measures an interference power of at least part of subcarriers among a plurality of subcarriers in each of the plurality of subcarrier blocks. The derivation unit derives, from the interference power of subcarriers measured by the measurement unit, an average value of the interference power for each of the plurality of subcarrier blocks and a statistical value indicating a degree of variation in the interference power relative to the average value. The allocation unit allocates at least one subcarrier block to the terminal apparatus, based on the average value and the statistical value derived by the derivation unit.

Method for allocating radio channels and base station apparatus utilizing the same

To allocate a terminal apparatus to a time slot to which a plurality of subcarriers are assigned, a base station apparatus first acquires the strength of signals between the base station apparatus and the terminal apparatus. Then the base station apparatus specifies a group, containing the acquired strength, among a plurality of groups. The plurality of groups are predefined in a manner such that the ranges of values of the acquired strengths differs respectively. Time slots to be allocated are predefined respectively for the plurality of groups. A time slot corresponding to the specified group is selected, and a subcarrier to be assigned to the terminal apparatus is selected from among a plurality of subcarriers contained in the selected time slot.

Method for reducing deterioration in receiving performance and a radio apparatus using the method

A processing unit performs adaptive array signal processing. A modem unit performs modulation and demodulation processing. A derivation unit derives signal strength as radio communication qualities among a plurality of terminal apparatuses of half rate format. A control unit assigns time slots in a plurality of terminal apparatuses of half rate format to be communicated with a base station apparatus. The control unit selects two terminal apparatuses whose difference between signal strengths is smaller, from among the plurality of terminal apparatuses of half rate, and then assigns time slots, having predetermined relationships, in these selected terminal apparatuses.

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Kakamigahara, Japan

Makoto Nagai