64 results about "Tree routing" patented technology

A method for relaying a route request RREQ message by an intermediate node which is connected with at least one node using a tree topology in a mobile communication system including a destination node and a source node which sends the RREQ message to the destination node via at least one intermediate node, to thus establish an optimal route for communications. The RREQ message is received along the route other than the tree route, and the first information is updated using its information. The intermediate node relays to a next intermediate node the RREQ message containing the updated first information.

The invention discloses a ZigBee sensor network tree route low-expense optimization method. The method comprises four stages of route finding packet sending, route finding packet processing, reply packet sending and reply packet processing. The flooding operation in the ZigBee sensor network tree route optimization process is limited in the aspects of transmitting nodes and hop count range of the route finding packet, so that flooding expense is obviously reduced. Meanwhile, intermediate nodes are allowed to reply the route finding packet, the flooding expense can be further lowered, and the route finding time delay of the optimal route can be reduced. Moreover, the energy optimal route can be selected in the condition of multiple routes by designing a new route length measurement mechanism, namely synthesized hop count, for simultaneously reflecting the hop count and node residual energy, node energy consumption is balanced, and the node survival time and network service life are prolonged.

A method and device are disclosed. In one embodiment the method includes driving a first clock domain reference signal on a first clock tree and driving a second clock domain reference signal on a second clock tree. The first tree routes the first signal from a PLL to a first clock domain drop off circuit and the second tree routes the second signal from the PLL to a second clock domain drop off circuit. A jitter produced from the second tree is less than a jitter produced from the first tree. The method continues by detecting any phase misalignment between the first signal and the second signal. The method also causes the first signal to be delayed so that it aligns with the second signal.

The invention provides a sensor network-oriented approximate query method commonly used for privacy protection. The method includes the following steps that the shared data structure of a base station and sensor nodes is used for enabling the numbers and collection data of the sensor nodes to be hidden in a vector; gathering nodes transmit the vector to the base station through a tree route; a linear system of equations is constructed in the base station, and a column diagram with global statistical information and a corresponding sensor node number are solved; the needed approximate query is completed according to the statistical information of the column diagram. According to the sensor network-oriented approximate query method, under the condition that privacy information is not leaked, approximate query energy consumption is reduced by the adoption of the strategies like network internal data gathering and a filter, and under the condition that the model does not need to be modified, accuracy control over the privacy protection approximate query can be achieved by the way of parameter adjustment.

A routing method of a wireless communication system is provided implementing advantageous features of both the tree routing and the link state routing. In the routing method, the system generates an adaptive tree table which defines a network in a tree structure of at least one branch with at least one node and each node generates a link state table which includes information on neighbor nodes, such that the packets are routed on the basis of the adaptive tree table and the link state table. Advantageous mechanisms of the tree routing and the link state routing are combined, thereby it is possible to eliminate most single point of failures of conventional tree routing and provide shorter paths compared with conventional tree routing.

The invention discloses a method for realizing energy conservation of a wireless sensing node in a greenhouse tomato irrigating system. A ZigBee tree routing mechanism is improved through analyzing the requirement of tomato irrigating environment information and a ZigBee tree routing algorithm; during the data forwarding process of a sensing node, a next-hop routing node is selected by an energy comprehensive evaluation function; during the irrigation decision-making process, a coordinator judges whether the irrigation is needed according to the illumination, air temperature, humidity, relative humidity of the soil, and the current crop growth cycle acquired by the sensing node; when the irrigation is not needed, the coordinator predicts when the irrigation is needed; and prior to this process, the sensing node is in a dormancy state. By the improved ZigBee tree routing and the coordinator irrigation decision-making data request mechanism of the invention, the transmission of a data packet in an overall wireless sensing network is greatly reduced, the energy utilization ratio of the node is effectively improved, and the stable period of the wireless sensing network is prolonged.

A gateway selection method for a wireless mesh network is provided for selecting an optimal gateway includes building a spanning routing tree to a given network. Reference factors of routers are calculated regarding the network to total network capacity in association with the spanning routing tree. A router is selected which has the greatest reference factor as being an optimal gateway of the network.

The invention discloses a genetic algorithm based minimum-cost optical multicast tree routing method. The method includes two parts of edge initialization of a network and minimum-cost multicast tree iteration. The edge initialization of the network mainly includes completing initialization of edges in the network, representing the edges with integer multiples of unit capacity with multiple unit capacity edges, and conveniently applying a genetic algorithm to optimize an information transmission path and an encoding method. The minimum-cost optical multicast tree iteration mainly includes the steps of selection, intersection, variation, bad gene removal and the like. Some bad genes are removed from a gene pool according to a designed fitness function value in the process of iteration every time, so that size of an algorithm searching space can be greatly decreased, convergence rate of the algorithm is increased beneficially, and an optical multicast tree with less cost is found out. The information transmission routing method is smallest in total number of found and needed information transmission links meeting the requirement on multicast request rate, and minimum in encoding operation times.

A method for relaying a route request RREQ message by an intermediate node which is connected with at least one node using a tree topology in a mobile communication system including a destination node and a source node which sends the RREQ message to the destination node via at least one intermediate node, to thus establish an optimal route for communications. The RREQ message is received along the route other than the tree route, and the first information is updated using its information. The intermediate node relays to a next intermediate node the RREQ message containing the updated first information.

A method and device are disclosed. In one embodiment the method includes driving a first clock domain reference signal on a first clock tree and driving a second clock domain reference signal on a second clock tree. The first tree routes the first signal from a PLL to a first clock domain drop off circuit and the second tree routes the second signal from the PLL to a second clock domain drop off circuit. A jitter produced from the second tree is less than a jitter produced from the first tree. The method continues by detecting any phase misalignment between the first signal and the second signal. The method also causes the first signal to be delayed so that it aligns with the second signal.

The invention discloses a dynamic clustering based multi-gateway WMN load balancing realization method in presence of IEEE802.11s. The dynamic clustering based multi-gateway WMN load balancing realization method in presence of IEEE802.11s comprises the steps of regarding a gateway node as a cluster head and a gateway MAC address as a cluster identifier; adding the cluster head and the cluster identifier in an RANN frame and a PREQ frame to realize cluster selection and cluster segmentation of a common node; modifying the processing process of the PREP frame and the PERR frame to maintain a transcendental tree routing and realize smooth transition of a routing list and a gateway load when the cluster of the node is changed; and giving comprehensive consideration to the path Metric from the node to the gateway and the load condition of the gateway per se when the common node selects the cluster, and selecting an optimal gateway to realize the purpose of balancing the gateway load, wherein the load volume is the proportion of the length of a transmission queue buffering region of a wired network card of a gateway node to the total length of the queue, and is added in the RANN frame for broadcasting. According to the dynamic clustering based multi-gateway WMN load balancing realization method in presence of IEEE802.11s, the dynamic clustering based multi-gateway wireless Mesh network and gateway load balancing is realized, the network overhead is reduced, the gateway load is balanced and the performance of the whole network is accordingly improved.

Computer method and apparatus for connection tree routing in visual modeling of software is disclosed. Tree routing style is represented as a property of a subject connection. A router object manages location of bendpoints of the subject connection in a connection tree. The subject connection maintains an end node as its target instead of a trunk element of the connection tree. The router object is formed of a hierarchy of routers including branch routers, tree routers and forest routers. Different routers maintain different aspects of the tree data forming display of the connection tree.

The invention discloses a compressed data collection method for a mobile wireless sensor network, which comprises the following steps of: firstly, designing a Treelet-based sparse representation baseby utilizing the space-time correlation of sensor node perception data; secondly, designing a sparse random measurement matrix; then, designing a Brown tree routing algorithm for data collection; andfinally, carrying out compressed data reconstruction at the Sink node according to the sparse representation base, the sparse random measurement matrix and the Brown tree route. By adopting the method, the data collection efficiency of the sensor network can be improved, the total cost of the nodes of the sensor network is reduced, and the life cycle of the network is prolonged to a certain extent.