Electronics and Telecommunications Research Institute

Motorola Mobility LLC

Yoonmee Doh

Noseong Park

Cheol Sig Pyo

Jong-Arm Jun

Sun-Joong Kim

Hyunhak Kim

Jong-Suk Chae

Yao Zhiying

Cheol-Sig Pyo

Jisun Lee

Chang Sub Shin

Bong Soo Kim

Matthew R Perkins

Yan Huang

Sun Joong Kim

Gwang Ja Jin

Zhiying Yao

So Young Hwang

Hyun-Hak Kim

Sung Joong Kim

No-Seong Park

Provided is a Media Access Control (MAC) technology that may improve a data transmission performance in an asynchronous sensor network. The MAC technology may increase a waked-up time interval of a reception node to thereby continue to receive traffic from a transmission node, and change a frequency band where data is transmitted and received to thereby reduce occurrence of collision. Also, when the wake-up time interval of the reception node is similar to a wake-up time of a neighboring node, the wake-up time interval of the reception node may be moved to another time interval, thereby improving the data transmission performance.

Sensor node for using asynchronous MAC

A time synchronization method in a wireless sensor network, a low power routing method using a reservation scheme, and an apparatus for performing the method are provided. The time synchronization method in the wireless sensor network may include: receiving a first synchronization request command packet from a parent node that manages time synchronization for a predetermined synchronization region; receiving, from the parent node, a second synchronization request command packet that has a transmission timestamp value of the first synchronization request command packet; and performing time synchronization for a child node based on a reception time of the first synchronization request command packet, a reception time of the second synchronization request command packet, and the transmission timestamp value of the first synchronization request command packet.

Time synchronization and routing method in wireless sensor network, and apparatus for enabling the method

Provided is a data transmission method of a plurality of sending nodes in a sensor network. In the data transmission method, data is generated to be transmitted to a receiving node, respectively. Headers of the generated data are transmitted to the receiving node, respectively, in response to a Wake-up Notification Message (WNM) from the receiving node. A Grant Notification Message (GNM) for selecting one of the plurality of sending nodes is received from the receiving node. The plurality of sending nodes transmit a payload of the generated data according to the GNM, or switch into sleep mode without data transmission.

Data transmission method in sensor network

Disclosed is a method of preventing overlap of multiple PANs in a ZigBee network. According to the method of preventing overlap of multiple personal area networks (PANs) in the ZigBee network, a first node included in a first PAN of the ZigBee network verifies whether overlap of the multiple PANs occurs by verifying packets received from neighbor nodes, identifies beacon information of a neighbor node that causes the overlap of the multiple PANs by gradually adjusting radio frequency (RF) transmission wave, and adjusts a communication range based on the beacon information.

Multiple pans conflict resolution method in zigbee

A method and apparatus for address assignment and node scheduling within an ad-hoc communication system is provided herein. During operation a personal area network coordinator (PANC) () will divide a superframe () into a plurality of slots, assigning each sub-tree under the PANC's direct child node to each slot for communication with the PANC. Each sub-tree coordinator will be assigned a same logical address by the PANC. As a result, a sub-tree coordinator synchronizes to the PANC node in only one subsuperframe slot assigned by the PANC with different sub-tree coordinators synchronizing to the PANC in different slots.

Node scheduling and address assignment within an ad-hoc communication system

Provided are a sensor node of a low power for a monitoring application in a mesh sensor network using a time division access scheme, and a routing method thereof. The routing method of the sensor node may include: transmitting a beacon containing routing information to neighboring nodes in a first time slot within a first beacon interval that is allocated to the sensor node; and receiving a beacon from each of the neighboring nodes in a second time slot within a second beacon interval that is allocated to each of the neighboring nodes.

Sensor node of low power for monitoring application in mesh sensor network using time division access scheme, and routing method thereof

Provided is a method of managing addresses of incommunicable nodes in a ZigBee network, and more particularly, a method of managing address values of a plurality of nodes that form a ZigBee network by efficiently withdrawing address values from nodes which are incommunicable for reasons of abnormality. An address management process can be performed using two methods. According to a first method, a parent node withdraws address values of child nodes that do not transmit a hello message for a predetermined period of time. According to a second method, a parent node transmits a periodic or non-periodic request message to child nodes, and the child nodes, which receive the request message, immediately transmit a hello message to the parent node. Then, the parent node withdraws address values of child nodes that do not respond to the request message sent by the parent node more than a predetermined number of times. An address value assignment process and a process for nodes that have their address values withdrawn are also provided.

Method of managing address spaces of incommunicable nodes in ZigBee network

The present invention relates to a sensor network having node architecture for performing trust management of neighboring sensor nodes, and to an adaptive method for performing trust management of neighboring sensor nodes for monitoring security in the sensor network. The sensor network includes a base station and a plurality of sensor nodes for reporting sensed information packets to the base station through radiofrequency signals relayed by other sensor nodes. A judge sensor node may have a trust estimator in its node architecture to evaluate trustworthiness of a neighboring suspect sensor node by determining a personal reference and receiving personal references from jury sensor nodes. Based on the trustworthiness of the suspect, the judge may modify a route for transmitting packets to the base station.

Wireless sensor network and adaptive method for monitoring the security thereof

A sensor node of a wireless sensor network includes a first sensor node module for generating and processing, when it is activated, a first sensing signal to detect occurrence of an event based on the first sensing signal; and a second sensor node module for generating and processing a second sensing signal, when it is activated, to monitor state transition of the event based on the second sensing signal. Further, when the occurrence of the event is detected, the first sensor node module is inactivated and the second sensor node module is activated.

Sensor node of wireless sensor networks and operating method thereof

A regional positioning method and apparatus in a wireless sensor network (WSN) is provided. The regional positioning method in a WSN, the regional positioning method including: setting a locating premise in the WSN based on a signal strength of an anchor node; sensing an event where a sensor node, installed in a target and called a target node, joins the WSN; detecting a locating premise where the target node is located based on the sensing of the event; and recognizing a location of the target based on the detected locating premise.

Regional positioning method and apparatus in wireless sensor network

Provided a method and device for efficiently retransmitting packets of which transmissions failed in wired/wireless network including detecting continuity by detecting whether or not a sequence ID of a received packet is continuous with a start sequence ID or an end sequence ID of packets included in reception blocks which are generated in advance of the received packet; depending on the result of the detection, manipulating reception blocks to renew or delete the reception blocks or generate a new reception block by using the sequence ID of the received packet; and transmitting an EBN (Explicit Block NACK) for requesting retransmission of lost packets in units of a block when discontinuity is detected.

Growing community of inventors

Daejeon, South Korea

Yoonmee Doh