Abstract: A method for realizing route discovery in a network includes: classifying a level of a node in the network; receiving a route request packet from a node adjacent to the node; comparing a node level indicated by node level information contained in the received route request packet with the level of the node; updating, in a case where the level of the node is higher than the node level indicated by the node level information contained in the route request packet, the node level indicated by the node level information contained in the route request packet to be the level of the node; and forwarding the updated route request packet to other nodes adjacent to the node.

Abstract: A wireless communication system is provided. A control device includes: a receiver configured to be able to receive information from radio frequency channels; a processor that judges whether a first channel is congested, and generates switchover instruction information when the first channel is judged to be congested; and a transmitter that transmits the switchover instruction information. Each node device includes: a receiver that receives information through the first channel; a transmitter that transmits information through a transmission channel; and a processor that recognizes whether a hop count from the control device is one, selects a second channel and specifies it as the transmission channel in a first case in which the receiver receives the switchover instruction information from the control device and the hop count is recognized as one, and specifies the first channel as the transmission channel in a second case in which the first case does not hold.

Abstract: A mobile base station includes a detecting unit that detects communication information concerning another cell; a switching unit that based on the detected communication information, switches a communication resource used by the mobile base station to a communication resource different from that used in the other cell; a communication resource reporting unit that reports to a mobile terminal in a cell of the mobile base station, the communication resource switched to by the switching unit; and a communication information reporting unit that reports to a base station outside the cell of the mobile base station, communication information concerning the communication resource switched to by the switching unit.

Abstract: A communication node that is capable of preventing a packet collision from occurring is provided. In a wireless network that connects a plurality of communication nodes in a multi-hop fashion, the communication node selects a high-communication-quality frequency to be used for transmission, sets frequency information in a channel assignment information part of a packet, and transmits the packet to a communication node that is a next hop destination. The communication node may recognize the frequency used for each hop from the frequency information set in the channel assignment information part of the received packet. Recognizing the frequency used for each hop, the apparatus may prevent the use of a frequency that could cause a hidden-terminal problem.

Abstract: A communication device is used by a mobile station to perform wireless communication with another mobile station. The communication device includes a processor configured to set a transmission resource according to a present position of the mobile station, the transmission resource being set based on transmission resource association information including different transmission resources assigned to plural assignment areas provided at different positions along a road through which the mobile station passes; and a transmitter configured to transmit data with the use of the transmission resource that has been set.

Abstract: A mobile communication apparatus includes a storage unit that stores therein correspondence information correlating area and transmission resource; an area deducing unit that deduces in which area the mobile communication apparatus is located; a selecting unit that selects the transmission resource correlated, in the correlation information stored by the storage unit, with the area deduced by the area deducing unit; and a transmitter that using the transmission resource selected by the selecting unit, transmits data to a second mobile communication apparatus.

Abstract: A communication system includes a roadside unit and a mobile communication unit that communicates with the roadside unit by using one of a plurality of communication channels. The mobile communication unit obtains, for each communication channel, a reception condition measurement representing the reception condition of a radio signal received from the roadside unit, creates information of a candidate channel for a receiving channel to be used to receive the radio signal from the roadside unit, and reports the candidate channel information to the roadside unit. On the other hand, the roadside unit assigns the receiving channel by selecting it from among the candidate channels, and reports the receiving channel to the mobile communication unit.

Abstract: There is provided a frequency control device that includes a frequency synchronizer to transform a radio signal to a baseband signal, a same signal correlator to obtain a first correlation value between a first signal in a first position in a first transmission symbol of the baseband signal and a second signal included in a second period, a different symbol correlator to obtain a second correlation value between a third signal included in a third period of the first transmission symbol and a fourth signal included in a fourth period, a frequency error estimator to estimate a frequency error added on the radio signal based on a phase rotation value of a difference value obtained by a subtraction of the second correlation value from the first correlation value, and a frequency corrector to correct the baseband signal to cancel the frequency error.

Abstract: A communication device is used by a mobile station to perform wireless communication with another mobile station. The communication device includes a processor configured to set a transmission resource according to a present position of the mobile station, the transmission resource being set based on transmission resource association information including different transmission resources assigned to plural assignment areas provided at different positions along a road through which the mobile station passes; and a transmitter configured to transmit data with the use of the transmission resource that has been set.

Abstract: A base station, for allocating to a mobile station a radio resource in a time direction and a frequency direction of a frame to perform radio communications with the mobile station, includes a zone forming unit configured to apply to zones, into which the frame is partitioned in the time direction, one of pilot transmission methods different in terms of a pilot allocation or a pilot directivity and in an allocation of transmission data to a plurality of mobile stations in a first zone adjacent to a second zone with a pilot transmission method different from the pilot transmission method of the first zone applied to the second zone, a scheduler configured to schedule a first mobile station moving at a low speed to a vicinity of a boundary with the second zone at a higher priority than a second mobile station moving at a high speed.

Abstract: A method for realizing route discovery in a network includes: classifying a level of a node in the network; receiving a route request packet from a node adjacent to the node; comparing a node level indicated by node level information contained in the received route request packet with the level of the node; updating, in a case where the level of the node is higher than the node level indicated by the node level information contained in the route request packet, the node level indicated by the node level information contained in the route request packet to be the level of the node; and forwarding the updated route request packet to other nodes adjacent to the node.

Abstract: The present invention relates to an apparatus and method of frame synchronization in broad band wireless communication systems. In an apparatus of frame synchronization in a mobile station, a time variant phase rotation compensator eliminates time variant phase rotation carried in received signals by conjugated multiplication between adjacent signal samples. Then, the processed signal is fed into a delay correlator to calculate a plurality of correlations between two successive frames. A local power calculator acquires an average power of several symbols centered on delayed correlation values. A normalizer normalizes the delayed correlation values with a local average power corresponding to the delayed correlation values. A maximum value detector selects the maximum value from normalized correlation values to trigger frame synchronizing and timing signals.

Abstract: There is provided a mobile communication apparatus capable of being mounted on a mobile body. The mobile communication apparatus includes a plurality of antennas arranged apart each other by certain distances; and a signal regenerator configured to enhance a signal propagating along at least one of detecting directions by summing products obtained by multiplying individual signals received from respective antennas of the plurality of antennas by respective weighting factors which correspond to the one of detecting directions, each of the detecting directions being defined based on a reference depending on a travelling direction of the mobile body.

Abstract: This invention provides an apparatus and method for preamble detection and integer carrier frequency offset estimation, which method comprises the steps of: determining the window of useful subcarriers in preamble transformed to frequency domain based on pre-determined possible integer carrier frequency offset and the length of the preamble, so as to select the useful subcarriers; extracting a plurality of subcarrier sequences having a length equal to that of the preamble from the useful subcarriers; calculating conjugative multiplications of each subcarrier and its neighboring subcarriers in the subcarrier sequences extracted; acquiring the real part of the conjugative multiplications; calculating the cross correlations between the real part of the conjugative multiplications and known preambles modulated by DBPSK, and outputting the calculated correlation values; and detecting preamble index of a target base station with the calculated correlation values to select a target cell, and estimating integer carri

Abstract: A drive control method for a micro machine device is provided. The micro machine device is made up of first and second electrodes opposed to each other and a dielectric layer disposed between them. The drive control method includes the steps of applying a control voltage between the first and the second electrodes so that an electrostatic force is exerted on the first and the second electrodes for displacing the first or the second electrode, and switching polarity of the control voltage at a predetermined period or a shorter period.

Abstract: A communication system includes a roadside unit and a mobile communication unit that communicates with the roadside unit by using one of a plurality of communication channels. The mobile communication unit obtains, for each communication channel, a reception condition measurement representing the reception condition of a radio signal received from the roadside unit, creates information of a candidate channel for a receiving channel to be used to receive the radio signal from the roadside unit, and reports the candidate channel information to the roadside unit. On the other hand, the roadside unit assigns the receiving channel by selecting it from among the candidate channels, and reports the receiving channel to the mobile communication unit.

Abstract: A mobile communication apparatus includes a storage unit that stores therein correspondence information correlating area and transmission resource; an area deducing unit that deduces in which area the mobile communication apparatus is located; a selecting unit that selects the transmission resource correlated, in the correlation information stored by the storage unit, with the area deduced by the area deducing unit; and a transmitter that using the transmission resource selected by the selecting unit, transmits data to a second mobile communication apparatus.

Abstract: There is provided a frequency control device that includes a frequency synchronizer to transform a radio signal to a baseband signal, a same signal correlator to obtain a first correlation value between a first signal in a first position in a first transmission symbol of the baseband signal and a second signal included in a second period, a different symbol correlator to obtain a second correlation value between a third signal included in a third period of the first transmission symbol and a fourth signal included in a fourth period, a frequency error estimator to estimate a frequency error added on the radio signal based on a phase rotation value of a difference value obtained by a subtraction of the second correlation value from the first correlation value, and a frequency corrector to correct the baseband signal to cancel the frequency error.

Abstract: A radio communication method in a radio communication system in which radio communication is performed between a radio communication base station apparatus and a radio communication mobile station apparatus, including: transmitting, by the radio communication mobile station apparatus, an implementation loss value of the radio communication mobile station apparatus to the radio communication base station apparatus.