Nippon Telegraph and Telephone Corporation

Ntt Broadband Platform, Inc.

Kengo Nagata

Shinya Otsuki

Kazuyoshi Saito

Satoru Aikawa

Tomoaki Kumagai

Yasuhiko Inoue

Atsushi Ohta

Akinori Hirukawa

Yusuke Asai

Yasushi Takatori

Akira Kishida

Shoko Shinohara

Takatoshi Sugiyama

Jun Mashino

Makoto Umeuchi

Kentaro Nishimori

Tomohiro Tokuyasu

Toshihiro Manabe

Hiroshi Hojo

Tadao Kobayashi

A base station according to an embodiment of the present disclosure includes a generation unit () that generates a beacon including switching information () indicating whether to cooperatively use a frequency channel and a transmission unit () that transmits the beacon.

Base station, terminal apparatus, and wireless communication method

A base station () according to an embodiment includes a data processing unit () and a wireless signal processing unit (). The data processing unit () generates a MAC frame. The MAC frame includes input data and an identification bit (CB). The identification bit (CB) indicates that data is extended broadcast data. The wireless signal processing unit () converts the MAC frame into a wireless signal to distribute the wireless signal.

Utilizing wireless distribution content

A data processing apparatus () according to an embodiment includes a data processing unit () and a wireless unit (). The wireless unit receives the data converted by the data processing unit and wirelessly transmits the input data to an access point. The data processing unit converts, when a remaining amount input from a battery () is in a first state, the input data with a first setting and outputs the converted data to the wireless unit. The data processing unit converts, when the remaining amount of the battery is in a second state different from the first state, the input data with a second setting and outputs the converted data to the wireless unit. A capacity per unit time of the data after conversion is different between the first setting and the second setting.

Data processing apparatus, data processing method, and data processing program

When a transmission rate of each of lines that transmit data simultaneously between two STAs by using a plurality of radio channels and/or MIMO can be set independently, one data frame is fragmented in accordance with the transmission rates of the respective lines so as to generate a plurality of data packets having the same packet time length and data sizes equal to or smaller than a maximum data size. Those data packets are transmitted simultaneously by using a plurality of radio channels, or one radio channel and MIMO, or a plurality of radio channels and MIMO.

Wireless packet communication method

In retransmission processing due to a failure of transmission of data packets, a plurality of data packets are simultaneously transmitted between two STAs by utilizing multiple wireless channels and MIMO, and the number of idle channels and the number of retransmission packets are compared. Then, when both of the numbers are different or only when the number of idle channels is larger than the number of retransmission packets, the retransmission packets are reconstructed according to the number of idle channels, and the reconstructed retransmission packets are simultaneously transmitted by using the idle channels.

Wireless packet communication method and wireless packet communication apparatus

An interference cancelling station ICS includes a transmission weight factor calculating unit calculating a transmission weight factor wand an interference cancelling data signal transmitting unit generating an interference cancelling data signal by multiplying, by the transmission weight factor w, a data signal transmitted by a base station BSb of the wireless communication system B and transmitting the interference cancelling data signal in synchronization with timing with which the base station BSb of a wireless communication system B transmits the data signal, and a mobile station MSa of a wireless communication system A receives a data signal transmitted by a base station BSa of the wireless communication system A, the data signal having cancelled interference from the base station BSb of the wireless communication system B.

Wireless communication system, interference cancelling station, and interference cancelling method

A wireless relay device connecting a wireless terminal to one of a plurality of access networks with different wireless interfaces and performing relay processing between the wireless terminal and one of the plurality of access networks being connected, the wireless relay device including a wireless interface on local side to be connected to the wireless terminal, a plurality of wireless interfaces on network side to be connected to the plurality of respective access networks, and a connection control section which boots the plurality of wireless interfaces on network side when the wireless interface on local side receives a signal from the wireless terminal, connects a wireless interface on network side establishing a fastest connection and the wireless interface on local side, and connects the wireless terminal to an access network corresponding to the wireless interface on network side establishing the fastest connection.

Wireless relay device and wireless communication system

Data packets are transmitted between two STAs capable of using plural radio channels and MIMO together, by using idle channels and MIMO. When at least one idle channel has been detected, plural data packets are generated in the same number as the sum of MIMO numbers of the respective idle channels, in which the data packets are generated from one or plural data frames, and plural data packets having the same packet time length are transmitted simultaneously between the two STAs by using the idle channels and MIMO.

A plurality of types of available transmission rates to be used for transmission of data packets are individually managed for each receiver terminal. When there are a plurality of data packets to be transmitted onto a transmission buffer and when it is possible to transmit said plurality of data packets simultaneously, the packet sizes representative of the data amounts of the respective data packets are referred to as well as the transmission rates of the respective data packets associated with the receiver terminals. The packet time lengths (transmission times) defined by the packet sizes and transmission rates are checked for the respective data packets. A plurality of data packets whose packet time lengths are approximately equal to each other are selected regardless of their receiver terminals. The transmissions of the plurality of selected data packets are commenced simultaneously by use of a plurality of radio channels.

For data packet transmission in special format generated by connecting or patching data frames, a request packet and reply packet receivable only by STAs supporting the special format are transmitted/received before the data packet transmission, to check and manage the STA supporting the special format. Based on management information in own station, the data packet is transmitted in the special or standard format according to a receive-side STA. For generating plural data packets in special format in which plural data frames are patched, the plural data frames having subheaders added are connected and divided to data blocks. A main header including information necessary to restore patched data frames are added to each data block, and a control information field and a frame check field of a data packet are added before and after the data block having the main header added thereto, respectively, to generate data packets.

Wireless packet communication method and apparatus

A transmit-side STA transmits a wireless packet using a wireless channel which has been determined to be idle by both a physical carrier sense for determining based on received power whether the wireless channel is busy or idle and a virtual carrier sense for determining the wireless channel to be busy during set transmission inhibition time. At this time, the transmit-side STA sets transmission time used for the virtual carrier sense to a paired wireless channel which is affected by leakage from a transmitting wireless channel. This allows for setting transmission inhibition time to a paired wireless channel even when the paired wireless channel cannot successfully receive due to the effect caused by leakage from the transmitting wireless channel.

A plurality of data packets that contain sequence numbers, respectively, are transmitted simultaneously between two STAs by using a wireless channel and MIMO. An STA receiving the plurality of data packets transmitted simultaneously by using MIMO generates a single ACK packet containing information that corresponds to a sequence number of each data packet successfully received, and transmits the single ACK packet to a transmit-side STA without using MIMO. Thus, a ratio of successful ACK packet receptions to total receptions can be increased. An effect of improving throughput achieved by simultaneous transmission can also be ensured.

In a wireless packet communication method for transmitting a plurality of wireless packets simultaneously by using multiple wireless channels determined to be idle by carrier sense, a wireless channel determined to be idle and MIMO, or the multiple wireless channel and the MIMO, a mandatory channel that is always used for transmission is set. The wireless packets are transmitted by using the wireless channel(s) including the mandatory channel only when the mandatory channel is idle. That is, in case of transmitting a plurality of wireless packets simultaneously, transmission is performed by using the wireless channel(s) including the mandatory channel, and transmission is not performed when the mandatory channel is not idle.

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Yokohama, Japan

Kengo Nagata