Abstract: One embodiment provides a wireless apparatus including: a reception unit which receives a data signal having a header field and a data field, the header field including a reply request which specifies either an acknowledgement or a negative acknowledgement; a decision unit which decides a reception result indicating whether the header field and the data field have been received successfully or unsuccessfully; and a transmission unit which transmits the acknowledgement or the negative acknowledgement in accordance with the reply request and the reception result of the data field when the header field has been received successfully, and transmits the negative acknowledgement when the header field has been received unsuccessfully.

Abstract: According to one embodiment, a wireless receiving apparatus includes a detector, a demodulator, a determination unit and a setting unit. The detector detects a wireless frame which has a received power level higher than a carrier detection threshold when the wireless frame is received. The determination unit determines a connection status in accordance with whether or not the demodulation is successful. The setting unit sets the carrier detection threshold at a first threshold if the connection status is an initial status where demodulation of a connection request frame is not successful, and which sets the carrier detection threshold at a second threshold if the connection status is other than the initial status, the second threshold being a variable value and larger than the first threshold.

Abstract: According to one embodiment, a wireless communication terminal including a receiver, a first processor, a first storage, a second storage, a second processor, and a transmitter is provided. The receiver receives one physical packet that includes at least one frame body field, a first field including information on a length of the frame body field, a second field used to detect an error of the frame body field, and a sequence number field including a sequence number corresponding to the frame body field. The second storage retains a successively and successfully received maximum sequence number on the basis of a result of the first processor. The transmitter transmits a response frame indicating the successively and successfully received maximum sequence number when the first processor extracts at least one correct frame body.

Abstract: A radio communication method stores a plurality MAC frames for each of a plurality of destinations. The method decides the longest transmission time of transmission times needed to transmit the plurality of MAC frames to each of the plurality of destinations within a fixed period. The method generates a plurality of physical frames for the plurality of destinations to transmit them at the same time by connecting the plurality of MAC frames and adding additional information to each connected MAC frame so as to be a frame length equivalent to a transmission time equal to the longest transmission time.

Abstract: According to one embodiment, a wireless communication apparatus using a first wireless communication scheme includes a transmitter and controller. The controller which controls IFSs so as to set, one of the first IFS and the second IFS as an IFS used during the first period. the controller sets the second IFS to at least a second period when a channel is idle during a period corresponding to a fourth IFS after one of the IFS is switched from the first IFS to the second IFS and when the channel becomes busy after the period corresponding to the fourth IFS is elapsed, the fourth IFS being an IFS before the transmission of a beacon signal, the second period being one of a plurality of first periods and being a period which includes timing for an estimated cycle of the beacon signal.

Abstract: According to one embodiment, a wireless communication apparatus is provided with first and second determination units. The first unit determines based on a first carrier sense threshold whether busy state or not and specifies a first time when busy state is determined with the first threshold, and determines based on a second carrier sense threshold smaller than the first threshold whether busy state or not and specifies a second time when busy state is determined. The second unit determines, if at least busy state is determined based on the second threshold and the second time precedes a reference time equal to or earlier than the first time, to perform processing for avoiding interference.

Abstract: According to one embodiment, a wireless communication terminal including a receiver, a first processor, a first storage, a second storage, a second processor, and a transmitter is provided. The receiver receives one physical packet that includes at least one frame body field, a first field including information on a length of the frame body field, a second field used to detect an error of the frame body field, and a sequence number field including a sequence number corresponding to the frame body field. The second storage retains a successively and successfully received maximum sequence number on the basis of a result of the first processor. The transmitter transmits a response frame indicating the successively and successfully received maximum sequence number when the first processor extracts at least one correct frame body.

Abstract: A wireless communication apparatus in a first wireless system is provided with first, second and third units, and a controller. The first unit transmits frames over a frequency channel using a short or long IFS as compared with a specific one used in a second wireless system with a communication range wider than the first wireless system. The second unit receives frames over the channel. The third unit determines an error characteristic in the received frames and/or a busy status of the channel. The controller controls at least either one of whether to change the frequency channel or not, and whether to change a duration of an interframe space or not.

Abstract: According to one embodiment, a wireless communication apparatus has a transmitter, a receiver, and a transmission timing instructor. The transmitter transmits a signal by using a first wireless communication scheme. The receiver receives a signal transmitted by using the first wireless communication scheme. The receiver detects a signal of which a frequency band includes at least a part of a frequency band used in the first wireless communication scheme, which is other than a signal transmitted by using the first wireless communication scheme. The transmission timing instructor instructs the transmitter to transmit a signal by using the first wireless communication scheme if the receiver does not receive a signal over a predetermined time from a detection of a signal other than a signal transmitted by using the first wireless communication scheme.

Abstract: A radio communication method stores a plurality MAC frames for each of a plurality of destinations. The method decides the longest transmission time of transmission times needed to transmit the plurality of MAC frames to each of the plurality of destinations within a fixed period. The method generates a plurality of physical frames for the plurality of destinations to transmit them at the same time by connecting the plurality of MAC frames and adding additional information to each connected MAC frame so as to be a frame length equivalent to a transmission time equal to the longest transmission time.

Abstract: According to one embodiment, a wireless communication apparatus includes a transceiver, an estimator and a controller. The transceiver transmits and receives a frame in a frequency band which is used by a first system executing communication in a first communication range determined by a first transmission power and a first antenna gain. The estimator determines whether an amount of interference in the frequency band from a second system is no less than a threshold, the second system executing communication in a second communication range which is larger than the first communication range and which is determined by a second transmission power and a second antenna gain. The controller increases a transmission power when the amount of interference is no less than the threshold.

Abstract: According to one embodiment, a wireless communication apparatus is provided with first and second determination units. The first unit determines based on a first carrier sense threshold whether busy state or not and specifies a first time when busy state is determined with the first threshold, and determines based on a second carrier sense threshold smaller than the first threshold whether busy state or not and specifies a second time when busy state is determined. The second unit determines, if at least busy state is determined based on the second threshold and the second time precedes a reference time equal to or earlier than the first time, to perform processing for avoiding interference.

Abstract: A wireless communication apparatus performs access control which starts transmission after a backoff time passes since an available state of a channel is detected through carrier sense, the backoff time being set based on a random value selected within a contention window width. The wireless communication apparatus includes a remaining time calculating unit which calculates a remaining time until a request delay time time-outs after data is generated, and a setting unit which sets the contention window width according to the remaining time calculated by the remaining time calculating unit.

Abstract: A wireless communication apparatus supports at least a second wireless communication scheme between a first wireless communication scheme and the second wireless communication scheme. The first wireless communication scheme requires that a wireless medium is determined to be busy when a reception level is equal to or greater than a minimum reception sensitivity level of a physical scheme. The apparatus includes a first processing unit and a second processing unit. The first processing unit is configured to set a value lower than a maximum transmission power of the first wireless communication scheme, for a maximum transmission power of the second wireless communication scheme and set a value greater than the minimum reception sensitivity level of the physical scheme, for a carrier sense level, when the second wireless communication scheme is used. The second processing unit is configured to carry out carrier sense using the carrier sense level.

Abstract: According to one embodiment, there is provided a wireless communication apparatus for making wireless connection in the first connection attempt state wherein a connection request is attempted using a predetermined frequency channel or the second connection attempt state wherein a connection request is attempted using a plurality of frequency channels. A frame generation unit generates a connection request frame which includes the first field for requesting a search of the plurality of frequency channels in response to occurrence of interference, and the second field indicating whether a corresponding frequency channel is a channel wherein occurrence of interference has been detected. A transmission unit transmits the connection request frame using the predetermined frequency channel in the first connection attempt state, and transmits the connection request frame using the plurality of frequency channels in the second connection attempt state.

Abstract: According to one exemplary embodiment, a communication apparatus includes: a measurement module which measures reception power of each field; a determination module which determines whether the reception power is within a range; a calculator which calculates a gain using the reception power if the reception power is not within the range; an adjuster which adjusts a field according to one of an initial gain and the calculated gain; a selector which selects a field length according to the number of field adjustments by the adjuster; and a transmitter which transmits information regarding the field length. When the number of the adjustments is lower than a first threshold value, the selector selects a first value, and when the number of the adjustments is equal to or higher than the first threshold value, the selector selects a second value that is higher than the first value, as the field length.

Abstract: According to embodiments, a wireless communication apparatus supports at least a second wireless communication scheme between a first, wireless communication scheme and the second wireless communication scheme. The first wireless communication scheme requires that a wireless medium is determined to be busy when a reception level is equal to or greater than a minimum reception sensitivity level of physical scheme. The apparatus includes a first processing unit and a second processing unit. The first processing unit is configured to set a value lower than a maximum transmission power of the first wireless communication scheme, for a maximum transmission power of the second wireless communication scheme and set a value greater than the minimum reception sensitivity level, of the physical scheme, for a carrier sense level, when the second wireless communication scheme is used. The second processing unit is configured to carry out carrier sense using the carrier sense level.

Abstract: In a wireless system of one embodiment, a first wireless device includes a first transmitter which transmits an end-of-transmission notification, and a first receiver which receives a change request signal sent from a second wireless device receiving the end-of-transmission notification. The second wireless device includes a second receiver which receives the end-of-transmission notification, and a second transmitter which transmits a change request signal when the end-of-transmission notification is received. The first transmitter transmits a signal at a longer interval after the first receiver receives the change request signal, and the second transmitter transmits a signal at a shorter interval after the second transmitter transmits the change request signal.

Abstract: In a wireless system of one embodiment, a first wireless device includes: a first transmitter which transmits an end-of-transmission notification; and a first receiver which receives a change request signal sent from a second wireless device receiving the end-of-transmission notification. The second wireless device includes: a second receiver which receives the end-of-transmission notification; and a second transmitter which transmits a change request signal when the end-of-transmission notification is received. The first transmitter transmits a signal at a longer interval after the first receiver receives the change request signal, and the second transmitter transmits a signal at a shorter interval after the second transmitter transmits the change request signal.

Abstract: According to one embodiment, a radio apparatus includes: a radio unit; a timer configured to count a first measurement time; a control unit configured to establish a first mode if the first measurement time is shorter than a first time, and establish a second mode if the first measurement time is longer than or equal to the first time; and a power control unit configured to control power to be supplied to the radio unit if the first mode is set and next data is not received even if a second time elapsed, and control power to be supplied to the radio unit if the second mode is set and next data is not received even if a third time elapsed, wherein the radio unit makes a transition to a sleep mode as a result of a power control by the power control unit.