Nippon Telegraph and Telephone Corporation

Shota Nakayama

Kenichi Kawamura

Keisuke Wakao

Yasushi Takatori

Takatsune Moriyama

Tomoyuki Yamada

Akira Kishida

Hiroshi Nakamoto

Daisuke Murayama

A communication system includes a terminal configured to wirelessly communicate with a base station, a plurality of IoT terminals, and a control device. The control device includes a processor; and a memory that includes instructions, which when executed, cause the processor to execute the following steps: selecting an IoT terminal around a dead zone and transmitting a command of signal transmission to the selected IoT terminal. The selected IoT terminal includes a receiver configured to receive the command, and a transmitter configured to transmit a signal according to the command. The terminal receiving the signal transmitted from the selected IoT terminal performs a connection operation for avoiding the dead zone.

Communication system, connection designation control method, control apparatus and program

A wireless LAN system where an interfering communication device is present around a base station device and a terminal device includes an interference control signal transmitter that transmits an interference control signal that causes the interfering communication device to wait for transmission, and an interference control signal management device that collects wireless environment information, sets wireless LAN communication between the base station device and the terminal device, which are protection targets, as protected communication, and causes the interference control signal transmitter to transmit an interference control signal that causes the interfering communication device to wait for transmission, and the interference control signal management device instructs the interference control signal transmitter to start transmitting the interference control signal when detecting a start of the protected communication and instructs the interference control signal transmitter to stop transmitting the interference control signal when detecting a stop of the protected communication.

Provide a wireless local area network (LAN) system, an interference control signal management device which are capable of limiting interference

Provided is a wireless communication system that performs priority control by setting, depending on a type of transmission data, a channel use period during which exclusive use of a channel after a right to access the channel is acquired is permitted. The wireless communication system includes a measurement unit that measures quality measurement information related to a quality of wireless communication, a parameter setting unit that makes, when a latency in transmission of a prioritized frame due to transmission of a non-prioritized frame is not expected based on the quality measurement information measured by the measurement unit, settings such that the channel use period for the transmission of the non-prioritized frame is changed to be longer, and a MAC frame generation unit that generates a MAC frame which permits continuous transmission of the non-prioritized frames within the channel use period set by the parameter setting unit.

System and method for performing priority control in wireless communication

A wireless LAN system in which a BSS composed of one wireless LAN base station and a plurality of wireless LAN terminals belonging to the wireless LAN base station, is set as a unit, and a plurality of the BSSs using an identical channel respectively perform uplink multi-user transmission, includes a radio control apparatus that is connected to the wireless LAN base station of each of the plurality of the BSSs and a wireless LAN terminal of the plurality of wireless LAN terminals of each of the plurality of the BSSs, and configured to collect radio information indicating interference states of respective radio waves, group sets of BSSs of the plurality of the BSSs, which are outside of radio wave reachable ranges of each other, as one of a plurality of groups among the plurality of the BSSs using the identical channel according to the radio information, and perform control to shift a timing of channel access for performing uplink multi-user transmission between the plurality of groups.

Wireless LAN communication system, uplink control method, and wireless control device

Provided is a wireless LAN system in which an interference control signal transmitter that is provided in the surroundings of the wireless LAN base station and the wireless LAN terminal, and is configured to collect wireless environment information regarding the interfering AP/STA, and transmit, to the interfering AP/STA, an interference control signal that is to be used to set a transmission waiting period; and an interference control signal management device configured to collect the wireless environment information from the interference control signal transmitter, determine the interference control signal transmitter whose communication area includes the interfering AP/STA based on the wireless environment information, and control the determined interference control signal transmitter to transmit the interference control signal to be used to set the transmission waiting period that corresponds to a length of time of the communication between the wireless LAN base station and the wireless LAN terminal, wherein while the interfering AP/STA that has received the interference control signal sets the transmission waiting period, the wireless LAN base station and the wireless LAN terminal preferentially perform communication.

Wireless LAN system and interference control method

In a random access radio communication system configured to perform downlink communication from a radio base station to radio terminals by random access, the radio terminals include one or more low latency terminals requiring low latency and one or more non-low latency terminals not requiring low latency, and the low latency terminals and the non-low latency terminals are configured to be distinguished by service set identifiers (SSIDs). The random access radio communication system includes terminal assignment destination control unit of distinguishing the low latency terminals and the non-low latency terminals in accordance with the SSIDs and evenly distributing the terminals into a plurality of communication channels, and random access control unit of performing priority control on the low latency terminals and the non-low latency terminals for each communication channel so that the downlink communication in the low latency terminal satisfies a predetermined delay time.

Random access wireless communication system and random access wireless communication method

A wireless LAN communication device generates an MPDU by attaching a MAC header to transmission data, generates an A-MPDU subframe by attaching an MPDU delimiter to the MPDU, generates an A-MPDU by aggregating a plurality of A-MPDU subframes, and transmits the A-MPDU. The wireless LAN communication device includes: an MPDU duplicating means for determining whether or not transmission data is a redundancy target according to a required quality of the transmission data, determining that an MPDU generated from the transmission data determined to be a redundancy target is a redundant MPDU, and generating a duplicate MPDU by duplicating the redundant MPDU; and an A-MPDU generating means for generating an A-MPDU that includes the redundant MPDU and the duplicate MPDU.

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Tokyo, Japan

Shota Nakayama