Abstract: Disclosed are a method and system for connecting lower nodes to one another to increase scalability in a ZigBee network. The method includes approving a participation request to excess lower nodes requesting participation in higher nodes where network addresses set with respect to the higher nodes are allocated to all of the lower nodes; when a transmission message is received from the excess lower nodes, analyzing the received transmission message and determining a node for transmitting the transmission message; and transmitting the transmitted transmission message to the determined node.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The present invention relates to a radiation element and a device for cooling a heating element using the radiation element, which can reduce noise, increase discharge air volume, and improve cooling efficiency. The radiation element includes: a mounting part on which a heating element is mounted; and air discharging means mounted on the mounting part having a space for receiving a cooling fan and a number of air discharge slits for discharging air generated from the cooling fan in the horizontal direction along the circumference of the cooling fan.