Abstract: The present invention relates to cognitive wireless sensor network technologies, and in particular to a medium access control method for a cognitive sensor network based on broadcast preamble sampling. A cognitive node in the cognitive sensor network adopts a periodical dormancy awakening mechanism. Firstly, a state of a primary user is judged by using a spectrum sensing technology. If the primary user is not active, a data sending node establishes a communication link by using a broadcast preamble code. Each neighbor node simultaneously considers information of hops from a gateway according to an awakening order, and independently determines to serve as a relay node for forwarding data. Furthermore, a transmission conflict between the cognitive node and the primary user may be caused due to return or missed alarm of the primary user. The present invention adopts a retransmission mechanism based on confirmation to ensure transmission reliability of data packets.

Abstract: The present invention relates to a Torus-Quorum based channel rendezvous method for directional antennas. A pair of directional antennas facing any side initially points to the other party mutually in one Torus-Quorum system cycle through a rotation closure attribute of a Torus-Quorum system; and a receiver and a sender switch to a same available channel according to frequency hopping sequences to realize channel rendezvous. In the Torus-Quorum based channel rendezvous method for directional antennas proposed in the present invention, the directional antennas are rotated based on the Torus-Quorum, and elements are ensured to coincide with each other within limited time through the rotation closure attribute of the Torus-Quorum system, i.e., directions are opposite, thereby effectively shortening channel rendezvous time of the directional antennas.

Abstract: The present invention relates to the field of architecture of Internet of Things, specifically to a semantics-based architectural model of Internet of Things. The present invention puts forward the architecture of the Internet of Things based on the study of semantic Web, sensor network, sensor Web, wherein the architecture is divided into 7 layers: physical layer, perception layer, gateway layer, data layer, semantic layer, service layer and application layer. By means of semantic processing of sensor data and building of sensor ontology, the architecture is capable of realizing automatic discovery of heterogeneous resources, enhancing the expression ability of data, achieving effective sharing, reuse, integration, and access to data, improving interoperability of resources and accomplishing intellectualized service.

Abstract: The present invention discloses a method for controlling transmission security of an industrial communication flow based on an SDN architecture. The method comprises: designing a flow security control module in a management controller, performing in-depth parsing on industrial communication flow data, matching the parsing result with each preset industrial rule policy, and executing a control processing operation of the industrial rule policy, to implement transmission control of an industrial communication flow. The management controller comprises an industrial rule policy database used for storing all industrial rule policies set by a user. An SDN switch maintains a structure of a flow table, and an industrial communication flow is forwarded according to the flow table. The flow table comprises a security control identifier used for indicating whether security transmission of this communication flow needs to be controlled.

Abstract: Low power consumption networking method for 802.15.4e wireless device “WD” taking 4-20 mA loop power, including: a “WD” taking loop power; constructing a WD oriented to ultra-low power consumption; the WD implementing unidirectional time synchronization based on preceding wireless network; on basis of preceding time synchronization, completing neighbor discovery; the WD interacting with the wireless network; and pausing a preceding procedure according to a power monitoring result of an energy storage monitoring module.

Abstract: The present invention relates to the technical field of terminal devices of the Internet of Things, more specifically to a semantic method for terminal devices of the Internet of Things capable of analyzing the application characteristics of terminal devices of the Internet of Things, setting down the rules for building ontology base; analyzing and building initial ontology base by using the ontology base building tool; pre-processing information from network and sensors; collecting information uploaded by sensors, updating the initial ontology base, and expanding the ontology base by collecting information searched by network. The method establishes program plan by object-oriented mode, analyzes implementing results by using existing test data or simulated data, and realizes domain updating and expansion of sensor ontology according to specific applications. The whole development and evolution of sensor ontology is increasing gradually in a spiral form.

Abstract: Proposed is an anomaly detection method for communication behaviors in an industrial control system based on an OCSVM algorithm. According to the present invention, a normal behavior profile model and an abnormal behavior profile model, i.e. a dual-outline model, of communication behaviors in an industrial control system are established, parameter optimization is performed by means of a particle swarm optimization (PSO) algorithm, an optimal intrusion detection model is obtained, and abnormal Modbus TCP communication traffic is identified. According to the present invention, the false alarm rate is reduced by means of cooperative discrimination of the dual-outline detection model, the efficiency and reliability of anomaly detection are improved, and the method is more applicable to practical applications.

Abstract: The present invention relates to a robust coverage method for relay nodes in a double-layer structure wireless sensor network. The present invention is a local search based relay node 2-coverage deployment algorithm which, by means of reducing the global deployment problem to a local deployment problem, achieves optimal deployment while ensuring robustness. The method specifically comprises two steps: first 1-coverage and second 1-coverage, wherein the first 1-coverage comprises the three steps of construction of relay node candidate deployment locations, grouping of sensor nodes and local deployment of relay nodes, wherein the sensor nodes are grouped by means of a novel grouping method, and the complexity of the algorithm is reduced while ensuring optimal deployment.

Abstract: The present invention relates to a Torus-Quorum based channel rendezvous method for directional antennas. A pair of directional antennas facing any side initially points to the other party mutually in one Torus-Quorum system cycle through a rotation closure attribute of a Torus-Quorum system; and a receiver and a sender switch to a same available channel according to frequency hopping sequences to realize channel rendezvous. In the Torus-Quorum based channel rendezvous method for directional antennas proposed in the present invention, the directional antennas are rotated based on the Torus-Quorum, and elements are ensured to coincide with each other within limited time through the rotation closure attribute of the Torus-Quorum system, i.e., directions are opposite, thereby effectively shortening channel rendezvous time of the directional antennas.

Abstract: The present invention provides an AP handover method based on double wireless network interface cards. A mobile terminal actively scans the signal strength of an AP, compares the scanned signal strength with the signal strength of a currently accessed AP, and if the signal strength is greater than the signal strength of the current AP, starts handover; otherwise, continuously scans till the handover succeeds. To reduce the handover delay and in accordance with the characteristic that the moving paths are basically fixed in industrial application scenarios, the present invention provides a pre-learning mechanism, that is, before formal application, information such as the location of the AP and the handover sequence in the application scenario is learned and stored in a terminal node, so that specific scanning and handover can be implemented in formal application.

Abstract: The present invention discloses a method and system for realizing Open vSwitch that supports 802.1p. The method comprises: a priority mode configuration stage: the switch receiving a priority configuration statement of a user and parsing the configuration statement; a configuration storage stage: storing the parsed configuration information into a switch database; and a priority-based data forwarding stage: the switch putting a received data packet into a corresponding priority queue according to said configuration information and a flow table so as to forward the data packet. The system comprises a configuration module, a configuration information storage module and a priority-based forwarding module, wherein the data priority-based forwarding module comprises a configuration reading unit, a traffic control setting unit, a flow table storage unit, a data packet parsing unit, a flow table matching unit, a flow table executing unit, a scheduling unit, priority queues, a sending unit, etc.

Abstract: The present invention discloses a method for trusted booting of PLC based on a measurement mechanism, comprising the following steps: a step of initializing self firmware verification; a step of reading and computing firmware information about a PLC; a step of checking and storing one by one; and a step of verifying at the operation start stage. In the method of the present invention, a chip with a trusted function is used as a core of hardware computation. The PLC extends a Flash bus for loading by hardware of the method of the present invention. The hardware of the method of the present invention recognizes necessary boot information, verifies the integrity of the boot loader necessary for the PLC system through the integrity check method and ensures that the booted PLC system is in a trusted state. On the basis of ensuring validity and feasibility for the safety of a terminal device, the present invention can build a safe and trusted industrial control system operating environment.

Abstract: The present application discloses a method for automatically establishing an intrusion detection model based on an industrial control network, including: judging whether a first intrusion detection model meets preset detection requirements, and extracting communication behavior traffic data in real time if not; setting a training data set and a test date set according to the communication behavior traffic data; establishing an initial intrusion detection model according to the training data set; and testing the initial intrusion detection model using the test date set, and establishing a second intrusion detection model meeting the preset detection requirements according to the test result. The second intrusion detection model has high detection accuracy, thereby increasing intrusion detection rate of abnormal behavior and reducing false positive rate and false negative rate.

Abstract: The present invention relates to a wireless network communication technology, and in particular to a time synchronization error compensation method for multi-hop wireless backhaul network based on PTP. Based on PTP, the present invention uses an intermediate node to count the timestamps of transceiving the PTP synchronization message Sync and the delay request message Delay_Req, detect and compensate the local forwarding time of synchronization message Sync and the delay request message Delay_Req and the link delay of transmitting the two between nodes based on the linear regression technology, thereby finally implementing asymmetric delay correction of wireless links between the master and slave nodes and completing time synchronization error compensation.

Abstract: The present invention relates to wireless network technologies, and particularly to a chain-type wireless sensor network-oriented hybrid media access control (MAC) method. The present invention fully considers features of a chained or linear topology of a wireless sensor network applied in power transmission line monitoring and the like, adopts different access policies at different periods of the network, and proposes a method of time division access control Pipelined TDMA during busy periods and contention access control S-XMAC during idle periods. During busy periods, a pipelined scheduling transmission method is used to avoid the problem of hidden terminals so as to improve transmission reliability and resource utilization.

Abstract: The present invention relates to a wireless network communication technology, and in particular to a time synchronization error compensation method for multi-hop wireless backhaul network based on PTP. Based on PTP, the present invention uses an intermediate node to count the timestamps of transceiving the PTP synchronization message Sync and the delay request message Delay_Req, detect and compensate the local forwarding time of synchronization message Sync and the delay request message Delay_Req and the link delay of transmitting the two between nodes based on the linear regression technology, thereby finally implementing asymmetric delay correction of wireless links between the master and slave nodes and completing time synchronization error compensation.

Abstract: The present invention relates to wireless network technology and presents a permutation group-based channel rendezvous method for a multi-antenna cognitive radio network, allowing a cognitive user equipped with multiple antennas to achieve blind channel rendezvous without the need for clock synchronisation.

Abstract: The present invention provides an AP handover method based on double wireless network interface cards. A mobile terminal actively scans the signal strength of an AP, compares the scanned signal strength with the signal strength of a currently accessed AP, and if the signal strength is greater than the signal strength of the current AP, starts handover; otherwise, continuously scans till the handover succeeds. To reduce the handover delay and in accordance with the characteristic that the moving paths are basically fixed in industrial application scenarios, the present invention provides a pre-learning mechanism, that is, before formal application, information such as the location of the AP and the handover sequence in the application scenario is learned and stored in a terminal node, so that specific scanning and handover can be implemented in formal application.

Abstract: The present invention relates to a robust coverage method for relay nodes in a double-layer structure wireless sensor network. The present invention is a local search based relay node 2-coverage deployment algorithm which, by means of reducing the global deployment problem to a local deployment problem, achieves optimal deployment whilst ensuring robustness. The method specifically comprises two steps: first 1-coverage and second 1-coverage, wherein the first 1-coverage comprises the three steps of construction of relay node candidate deployment locations, grouping of sensor nodes and local deployment of relay nodes, wherein the sensor nodes are grouped by means of a novel grouping method, and the complexity of the algorithm is reduced whilst ensuring optimal deployment.

Abstract: The present invention discloses a method for controlling transmission security of an industrial communication flow based on an SDN architecture. The method comprises: designing a flow security control module in a management controller, performing in-depth parsing on industrial communication flow data, matching the parsing result with each preset industrial rule policy, and executing a control processing operation of the industrial rule policy, to implement transmission control of an industrial communication flow. The management controller comprises an industrial rule policy database used for storing all industrial rule policies set by a user. An SDN switch maintains a structure of a flow table, and an industrial communication flow is forwarded according to the flow table. The flow table comprises a security control identifier used for indicating whether security transmission of this communication flow needs to be controlled.