Abstract: Provided are a device, a system, and a method in which redundancy is changed in accordance with a line state, and thus the optimal redundancy can be set while the current settings are compared to the previous settings. A communication device measures line quality information from a received packet, and generates a redundancy change instruction based on information regarding a line. In a case where the communication device acquires line quality information for the second and subsequent times, the communication device compares the previous redundancy change instruction and the previous line quality information, to the current line quality information, and sets redundancy. Thus, it is possible to suppress the occurrence of congestion and satisfy a target value of the line quality, and to search for a condition which causes the redundancy to be the minimum.

Abstract: A packet collision among a plurality of access points is avoided and QoS is ensured. An access point that shares a wireless channel with a plurality of access points to carry out communication is provided with a function for determining, based on information contained in a polling communication signal or a broadcast signal transmitted from another access point, an access point (preceding AP) that is to perform polling communication immediately before the own station to form a group within which the order of the polling communication is determined, and after determining that a polling communication period of the preceding AP has ended, starting the polling communication period of the own station in a wireless network.

Abstract: Provided is a wireless transmission system including a plurality of access points and an access controller. The access controller determines a start standard time for a polling period for the plurality of access points to perform polling communication with a plurality of wireless terminals. The access controller generates a scheduling setting information indicating timings when the plurality of access points perform polling communication with the plurality of wireless terminals during the polling period. The access controller transmits, to each of the plurality of access points, a polling period start signal including the start standard time and a corresponding portion of the scheduling setting information for each of the plurality of access points. The plurality of access points perform polling communication with the plurality of wireless terminals based on respective polling period start signals.

Abstract: A communication device that performs bidirectional multiplex communication between a plurality of slave communication devices and the communication device is provided with: a first port connected to one end section of a transmission line to which the slave communication devices are connected; a second port connected to the other end section of the transmission line; and a current detection unit connected to the first port and the second port. An operation voltage is supplied from the communication device to the slave communication devices, a change of the quantity of a current flowing in the first port and/or the second port is detected by means of the current detection unit, and on the basis of the current quantity change, occurrence of disconnection in the transmission line is detected.

Abstract: To provide a delivery system by which an unmanned aerial vehicle can be safely landed at a landing site, and the unmanned aerial vehicle can be landed at the desired site with high accuracy, a delivery system, comprising: an unmanned aerial vehicle that delivers a package to a delivery destination; a control server that manages delivery of the package; and an access point set in a vicinity of a landing site of the unmanned aerial vehicle, wherein the unmanned aerial vehicle is configured to: communicate with the control server through the access point when inside a predetermined range; and communicate with the control server through a telecommunications carrier network outside of the predetermined range.

Abstract: Provided are a device, a system, and a method in which redundancy is changed in accordance with a line state, and thus the optimal redundancy can be set while the current settings are compared to the previous settings. A communication device measures line quality information from a received packet, and generates a redundancy change instruction based on information regarding a line. In a case where the communication device acquires line quality information for the second and subsequent times, the communication device compares the previous redundancy change instruction and the previous line quality information, to the current line quality information, and sets redundancy. Thus, it is possible to suppress the occurrence of congestion and satisfy a target value of the line quality, and to search for a condition which causes the redundancy to be the minimum.

Abstract: An object of the disclosed invention is to provide a polling-based multihop communication system capable of achieving robust communication. Solving means thereof is a (multihop communication) wireless transmission system including, as wireless stations, a base station, a plurality of relay stations connected at multiple stages by using the base station as a root, and a plurality of terminals connected to the relay stations, in which the base station and the relay stations perform communication using polling in one or more service periods which have been allocated to each of the base and relay stations in time division in advance in a system cycle.

Abstract: It is necessary to increase the scale of a sensor network to achieve high resource exploration efficiency. On the other hand, since there are increasing needs to extend the area of an exploration region and to detect deeper geological stratum and crust structures more accurately, the large-scale sensor network needs to be operated for a long period of several weeks or longer. In order to solve the problem, a sensor unit needs to be turned on always to perform measurement always. However, an auxiliary measurement unit is activated intermittently since the auxiliary measurement unit needs to acquire data at necessary timings only. On the other hand, during collection and transmission of data and charging of a battery, a sensor terminal detects whether power is supplied from a data collection and charging device and automatically turns off the sensor unit and the auxiliary measurement unit to activate a data transmission unit.

Abstract: A packet collision among a plurality of access points is avoided and QoS is ensured. An access point that shares a wireless channel with a plurality of access points to carry out communication is provided with a function for determining, based on information contained in a polling communication signal or a broadcast signal transmitted from another access point, an access point (preceding AP) that is to perform polling communication immediately before the own station to form a group within which the order of the polling communication is determined, and after determining that a polling communication period of the preceding AP has ended, starting the polling communication period of the own station in a wireless network.

Abstract: Provided is a method for effectively suppressing packet losses by burst losses without an increase in delay by adaptively or fixedly changing a size of an FEC encoded block even when the number of packets per unit time is small. Each communication device 101 includes a transmitting unit 102 and a receiving unit 103. The transmitting unit 102 has a function of calculating forward error correction (FEC) codes based on the number of packets per encoding time and a value of a burst loss time of a network line. The receiving unit 103 decodes an FEC encoded packet and measures line quality information of the network for transmission to the transmitting unit 102. The transmitting unit 102 transmits the packets at equal intervals for as long as it is required for encoding, and can change a system for calculating FEC based on the burst loss time and the encoding time.

Abstract: To enable configuration and control of a camera at the same time while providing a certain band and low-delay communication for video and/or voice data, a wireless surveillance camera device includes: a signal processing unit that applies signal processing to the video and/or voice data; and a configuration unit that acquires configuration information data related to video parameters and/or wireless parameters in the device, wherein data communication of the video and/or voice data is performed for a wireless base station based on a polling system, and data communication of the configuration information data is performed for the wireless base station based on a carrier sense system.

Abstract: An object of the disclosed invention is to provide a polling-based multihop communication system capable of achieving robust communication. Solving means thereof is a (multihop communication) wireless transmission system including, as wireless stations, a base station, a plurality of relay stations connected at multiple stages by using the base station as a root, and a plurality of terminals connected to the relay stations, in which the base station and the relay stations perform communication using polling in one or more service periods which have been allocated to each of the base and relay stations in time division in advance in a system cycle.

Abstract: To enable configuration and control of a camera at the same time while providing a certain band and low-delay communication for video and/or voice data, a wireless surveillance camera device includes: a signal processing unit that applies signal processing to the video and/or voice data; and a configuration unit that acquires configuration information data related to video parameters and/or wireless parameters in the device, wherein data communication of the video and/or voice data is performed for a wireless base station based on a polling system, and data communication of the configuration information data is performed for the wireless base station based on a carrier sense system.

Abstract: Provided is a wireless transmission system including a plurality of access points and an access controller. The access controller determines a start standard time for a polling period for the plurality of access points to perform polling communication with a plurality of wireless terminals. The access controller generates a scheduling setting information indicating timings when the plurality of access points perform polling communication with the plurality of wireless terminals during the polling period. The access controller transmits, to each of the plurality of access points, a polling period start signal including the start standard time and a corresponding portion of the scheduling setting information for each of the plurality of access points. The plurality of access points perform polling communication with the plurality of wireless terminals based on respective polling period start signals.

Abstract: Systems and methods for reducing overhead by using block acknowledgment with an all polling technique while attempting to meet latency and QoS requirements. Each node transmits a number of packets upon receiving a polling message. The Access Point (AP) then replies with a Block Acknowledgement (BlockAck), which is combined with a subsequent polling message and contains a bitmap that indicates 1 for a successfully received packet and 0 for a failed reception.

Abstract: Systems and methods for reducing overhead by using block acknowledgment with an all polling technique while attempting to meet latency and QoS requirements. Each node transmits a number of packets upon receiving a polling message. The Access Point (AP) then replies with a Block Acknowledgement (BlockAck), which is combined with a subsequent polling message and contains a bitmap that indicates 1 for a successfully received packet and 0 for a failed reception.

Abstract: Systems and methods directed towards improving reliability for wireless networks. Selective polling techniques are utilized to selectively poll stations within a wireless network in order to ensure that a station failing to properly transmit data is given an opportunity to rectify the transmission failure. The selective polling techniques can be applied to any polling-based system, thus maintaining backwards compatibility with legacy systems.

Abstract: In a wireless network system, the nodes share a frequency hopping pattern. A method comprises providing a channel list table which includes, for each transmitting node, one or more channel lists, each channel list containing conditions of the channels of the shared frequency hopping pattern that include at least one available channel for communications with a target node; selecting a channel of a next allocated time slot from the shared frequency hopping pattern at the transmitting node; selecting the channel list for the target node from the channel list table, to which the transmitting node transmits; checking if the selected channel is available based on the selected channel list; setting the selected channel at the transmitting node if the selected channel is available; and calculating a substitute channel from the channel list if the selected channel is not available.

Abstract: Systems and methods directed towards improving reliability for wireless networks. Selective polling techniques are utilized to selectively poll stations within a wireless network in order to ensure that a station failing to properly transmit data is given an opportunity to rectify the transmission failure. The selective polling techniques can be applied to any polling-based system, thus maintaining backwards compatibility with legacy systems.

Abstract: To correct a sensor data acquisition time with a simple hardware configuration, provided is a wireless sensor-network system including: a base station; and a plurality of sensing terminal nodes, the base station transmitting a beacon at predetermined intervals to the plurality of sensing terminal nodes, the plurality of sensing terminal nodes measuring data and transmitting, based on a reception of the beacon transmitted from the base station, the sensor data thus obtained to the base station, in which the plurality of sensing terminal nodes obtain, based on an internal clock, a time at which the beacon is received and transmit the time to the base station, and the base station corrects, based on the reception time transmitted from each of the plurality of sensing terminal nodes, the sensor data acquisition time.