Abstract: A computer-executed method is provided for IEEE 802.15.4 devices based on an active carrier sense based carrier-sense multiple access with collision avoidance (ACS-CSMA/CA) control program and standard CSMA/CA control program for coexistence of an IEEE 802.15.4 network composing of IEEE 802.15.4 devices and IEEE 802.11 network composing of IEEE 802.11 devices sharing frequency spectra between the networks. The computer-executed method is provided on an IEEE 802.15.4 device, and causes a processor of the IEEE 802.15.4 device to perform steps that include estimating a severity of IEEE 802.11 interference based on a severity estimation metric, selecting the ACS-CSMA/CA control program based on the estimated severity.

Abstract: A master station (111) and a slave station (121) each communicate an individually set, fixed number of communication frames in a cyclic period. The communication frame contains, as communication information, a sequence number and a period number. The master base station (113) and the slave base station (123) determine, upon communication of each communication frame in a wireless manner, if there is a missing communication frame on a basis of the communication information of a this-time communication frame and the communication information of a last-time communication frame. When there is a missing communication frame, a history management server (300) records communication history information of the last-time communication frame and of the this-time communication frame, as preceding/succeeding history information.

Abstract: A computer-implemented method is provided for discovering heterogenous neighbors in coexisting IoT networks including at least one Wi-Fi device and at least one of Zigbee coordinators, ZigBee routers and ZigBee end devices. The method includes generating a broadcast packet such that the broadcast packet emulates a ZigBee broadcast frame, transmitting the emulated broadcast packet using a transceiver of the at least one Wi-Fi device according to cross-technology communication (CTC) method, wherein the emulated broadcast packet is configured to trigger the at least one of the Zigbee coordinators and ZigBee routers having received the emulated broadcast packet to rebroadcast the received packet.

Abstract: A wireless smart utility network (Wi-SUN) device participating in a Wi-SUN network for coexistence with a Wi-Fi HaLow network sharing frequency spectra between the networks is provided.

Abstract: A computer-executed method is provided for IEEE 802.15.4 devices based on an active carrier sense based carrier-sense multiple access with collision avoidance (ACS-CSMA/CA) control program and standard CSMA/CA control program for coexistence of an IEEE 802.15.4 network composing of IEEE 802.15.4 devices and IEEE 802.11 network composing of IEEE 802.11 devices sharing frequency spectra between the networks. The computer-executed method is provided on an IEEE 802.15.4 device, and causes a processor of the IEEE 802.15.4 device to perform steps that include estimating a severity of IEEE 802.11 interference based on a severity estimation metric, selecting the ACS-CSMA/CA control program based on the estimated severity.

Abstract: A node device for forming a multi-hop network is provided. The node device is configured to avoid interference from coexisting interfering networks and includes a transceiver configured to receive and transmit data with respect to a Destination Oriented Directed Acyclic Graph (DODAG) Information Object message (DIO message), a memory configured to store computer executable programs including an interfered-node count (IC), single-rate link count (SLC), multi-rate link count (MLC), hop count (HP), path communication latency (PCL) and an interference efficient and multi-rate supported routing program CoM-RPL, and a processor configured to perform steps of the computer executable programs. The steps include determining if the received DIO message indicates a new DODAG or an existing DODAG.

Abstract: A node device for forming a multi-hop network is provided. The node device is configured to avoid interference from coexisting interfering networks and includes a transceiver configured to receive and transmit data with respect to a Destination Oriented Directed Acyclic Graph (DODAG) Information Object message (DIO message), a memory configured to store computer executable programs including an interfered-node count (IC), single-rate link count (SLC), multi-rate link count (MLC), hop count (HP), path communication latency (PCL) and an interference efficient and multi-rate supported routing program CoM-RPL, and a processor configured to perform steps of the computer executable programs. The steps include determining if the received DIO message indicates a new DODAG or an existing DODAG.

Abstract: A wireless smart utility network (Wi-SUN) device participating in a Wi-SUN network for coexistence with a Wi-Fi HaLow network sharing frequency spectra between the networks is provided.

Abstract: A wireless smart utility networks (Wi-SUN) device participating in a Wi-SUN network for coexistence with a Wi-Fi HaLow network sharing frequency spectra between the networks is disclosed. The Wi-SUN device includes a receiver to receive packets of neighbor Wi-SUN devices, a memory configured to store computer executable programs including a Hybrid carrier-sense multiple access (CSMA) control program and Wi-SUN Backoff control Program, a processor configured to execute the Hybrid CSMA control program, including instructions that cause the processor to perform steps of estimating a severity of Wi-Fi Halow interference based on a severity detection method, switching a backoff mode between predetermined backoff modes in response to the estimated severity, and performing a backoff procedure according to the selected backoff mode, and a transmitter to transmit packets.

Abstract: A delivery data transmission device (100A) is mounted on a train, and transmits delivery data. A redundancy-degree decision unit (115A) decides a redundancy-degree of an erasure-correction code to be applied to delivery data when a distance between the delivery data transmission device (100A) and a next arrival station the train stops at next becomes equal to or smaller than a threshold value. An encoding unit (116B) encodes the delivery data at an encoding rate corresponding to the redundancy-degree decided by the redundancy-degree decision unit (115A).

Abstract: A wireless smart utility networks (Wi-SUN) device participating in a Wi-SUN network for coexistence with a Wi-Fi HaLow network sharing frequency spectra between the networks is disclosed. The Wi-SUN device includes a receiver to receive packets of neighbor Wi-SUN devices, a memory configured to store computer executable programs including a Hybrid carrier-sense multiple access (CSMA) control program and Wi-SUN Backoff control Program, a processor configured to execute the Hybrid CSMA control program, including instructions that cause the processor to perform steps of estimating a severity of Wi-Fi Halow interference based on a severity detection method, switching a backoff mode between predetermined backoff modes in response to the estimated severity, and performing a backoff procedure according to the selected backoff mode, and a transmitter to transmit packets.

Abstract: A wireless smart utility network (Wi-SUN) device participating in a Wi-SUN network for coexistence with a Wi-Fi HaLow network sharing frequency spectra between the networks is provided.

Abstract: A delivery data transmission device (100A) is mounted on a train, and transmits delivery data. A redundancy-degree decision unit (115A) decides a redundancy-degree of an erasure-correction code to be applied to delivery data when a distance between the delivery data transmission device (100A) and a next arrival station the train stops at next becomes equal to or smaller than a threshold value. An encoding unit (116B) encodes the delivery data at an encoding rate corresponding to the redundancy-degree decided by the redundancy-degree decision unit (115A).

Abstract: A wireless communication device 1 encrypts a passphrase which corresponds to a communication mode after change and which is a character string for authentication by using an encryption key PTK corresponding to a communication mode before change, and transmits the encrypted passphrase to a wireless communication device 2, and also creates an encryption key PTK corresponding to the communication mode after change from the passphrase corresponding to the communication mode after change. The wireless communication device 2 receives the encrypted passphrase transmitted from the wireless communication device 1 and decrypts the encrypted passphrase by using an encryption key PTK corresponding to the communication mode before change, and also creates an encryption key PTK corresponding to the communication mode after change from the decrypted passphrase.

Abstract: Each of wireless communication devices 2A, 2B and 2C is configured in such a way as to transmit information about either a service or an application which the wireless communication device can provide, in accordance with a protocol which makes it possible to perform wireless communications with a wireless communication device 1 regardless of the setting of a communication mode to the wireless communication device 1, and the wireless communication device 1 is configured in such a way as to collect information about an application which is transmitted from each of the wireless communication devices 2A, 2B and 2C. As a result, the wireless communication device 1 can acquire the information about the providable application from each of the wireless communication devices 2A, 2B and 2C existing in the surroundings thereof regardless of the setting of a communication mode.

Abstract: A radio communication system includes a plurality of radio communication apparatuses including an active scan terminal and a passive scan terminal. After transmitting a probe request frame from one frequency channel, the active scan terminal continuously transmits the probe request frame from other frequency channels without waiting for a response frame from the other radio communication apparatuses, thereafter transmits the probe request frame from a response channel, which is a waiting channel, and waits for a response from the passive scan terminal, and superimposes, on the probe request frame, information concerning an offset time to the response and information concerning the response channel, and, after receiving the probe request frame, after the elapse of the offset time to the response, the passive scan terminal transmits a response frame from a frequency channel designated by the response channel information.

Abstract: Each of wireless communication devices 2A, 2B and 2C is configured in such a way as to transmit information about either a service or an application which the wireless communication device can provide, in accordance with a protocol which makes it possible to perform wireless communications with a wireless communication device 1 regardless of the setting of a communication mode to the wireless communication device 1, and the wireless communication device 1 is configured in such a way as to collect information about an application which is transmitted from each of the wireless communication devices 2A, 2B and 2C. As a result, the wireless communication device 1 can acquire the information about the providable application from each of the wireless communication devices 2A, 2B and 2C existing in the surroundings thereof regardless of the setting of a communication mode.

Abstract: A radio communication system includes a plurality of radio communication apparatuses including an active scan terminal and a passive scan terminal. After transmitting a probe request frame from one frequency channel, the active scan terminal continuously transmits the probe request frame from other frequency channels without waiting for a response frame from the other radio communication apparatuses, thereafter transmits the probe request frame from a response channel, which is a waiting channel, and waits for a response from the passive scan terminal, and superimposes, on the probe request frame, information concerning an offset time to the response and information concerning the response channel, and, after receiving the probe request frame, after the elapse of the offset time to the response, the passive scan terminal transmits a response frame from a frequency channel designated by the response channel information.

Abstract: A wireless communication device 1 encrypts a passphrase which corresponds to a communication mode after change and which is a character string for authentication by using an encryption key PTK corresponding to a communication mode before change, and transmits the encrypted passphrase to a wireless communication device 2, and also creates an encryption key PTK corresponding to the communication mode after change from the passphrase corresponding to the communication mode after change. The wireless communication device 2 receives the encrypted passphrase transmitted from the wireless communication device 1 and decrypts the encrypted passphrase by using an encryption key PTK corresponding to the communication mode before change, and also creates an encryption key PTK corresponding to the communication mode after change from the decrypted passphrase.