Chinese Academy of Sciences

Xiaoling Zhang

Haibin Yu

Bo Yang

Wei Liang

Peng Zeng

Miao Yang

Chaofan Ma

Weijie Xu

Zhijia Yang

Jun Wang

Shuai Liu

Yutuo Yang

Zhijun Shang

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. The second 1-coverage adjusts a threshold, selects from every group the sensor nodes covered by just one relay node, and uses a 1-coverage method to re-implement 1-coverage of the sensor nodes, thereby ensuring robustness, reducing the number of relay nodes deployed, and shortening the problem-saving time.

Robust coverage method for relay nodes in double-layer structure wireless sensor network

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. During idle periods, different MAC parameters are set for cluster head members and ordinary cluster members, so that the cluster head members can respond to requests in a more timely manner, and meanwhile, the ordinary cluster members save energy as much as possible, thereby meeting requirements for network real-time quality of the application system while saving energy of the network.

Chain-type wireless sensor network-oriented hybrid media access control method

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. The present invention defines channel hopping sequences whilst making full use of properties such as channel diversity, the closure nature of permutation groups, and multi-antenna concurrency; based on the permutation groups obtained by rotating a regular polyhedron or a regular polygon around different angles according to different types of axes of symmetry, cyclical splicing is implemented, and different antennas can, according to different rules, independently generate hopping sequences and switching channels; the sequence generating methods are various and flexible; the use of parallel search ensures that deterministic rendezvous with other cognitive users is achieved as quickly as possible and as much as possible in a limited time; and the present method is a highly efficient blind channel rendezvous method having wide applicability and suitable for use in large-scale wireless networks.

Permutation group-based channel rendezvous method for multi-antenna cognitive radio network

The present invention relates to a TDMA access method and device based on multiple access points. According to the problems that the existing method cannot simultaneously satisfy the demands of timeliness and reliability in actual industrial application and has low resource utilization rate, the present invention takes full consideration of the transmission characteristics and industrial automation application characteristics of wireless networks, and provides a TDMA access method and device based on multiple access points. The main ideas of the method in the present invention are: the multi-access point redundant communication manner is adopted to improve system reliability, beacon frames of multiple access points are utilized to perform time synchronization so as to improve synchronization precision, confirmation messages are fed back with regard to reliable access points to reduce the number of retransmissions, and a modularized multi-access point device design method is adopted to lower the difficulties of device maintenance and management.

TDMA access method and device based on multiple access points

A method for two-stage packet aggregation facing wireless sensor network with hybrid topology structure including: building various nodes in a wireless sensor network into a hybrid topology structure which combines the star topology and mesh topology; establishing a two-stage packet aggregation architecture for periodic sensor data based on the above described topology structure; determining the packet format, aggregating and disaggregating the two-stage packets based on the topology structure and aggregation architecture; according to the application, the aggregated nodes in the network configuring router nodes and aggregation attributes of the nodes; according to the aggregation attribute, the sensor nodes performing the first-stage aggregation and generates an first-stage aggregation packet; according to the aggregation attributes, the router node implementing second-stage aggregation and generating a second-stage aggregation packet; the aggregation nodes taking charge of disaggregating the aggregated packets. Embodiments of the invention adopt the above described hybrid topology structure, feature a two-stage packet aggregation method, decrease the overhead of packet-head, reduce the energy consumption of the nodes and inter-node interference, and save communication resources.

Method for two-stage packet aggregation facing wireless sensor network of hybrid topology structure

A method of achieving wireless sensor network (WSN) communication in a mesh and star topology network (MSTN), including: a) connecting a plurality of nodes in a WSN to form a mesh and star hybrid topology structure; b) based on the topology structure, defining a superframe structure based on IEEE 802.15.4-2006; c) based on the topology structure and superframe structure, defining methods for long period data processing, connectivity assessment, medium access control, channel measurement, frequency hopping, beacon frame formation, and two-stage resource allocation; d) based on the topology structure, superframe structure, and methods, defining a method for network establishment; and e) based on the network establishment method, defining a method for MSTN communications. The method features real-time communication, high reliability, and low energy consumption.

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Liaoning, China

Xiaoling Zhang