Abstract: A method of allocating logical channels in consideration of an interference range in a wireless sensor network includes defining logical channels to increase the number of available channels and determining the number of logical channels in accordance with the number of nodes within an interference range, allocating the logical channels to the nodes within the interference range so that the determined logical channels do not overlap each other, and exchanging data among the nodes using the allocated logical channels.

Abstract: Disclosed is a time slot allocation method for reducing consumption of energy in a wireless sensor network, including transmitting and receiving, by an upper node, a report request and a response to and from at least one lower node in order to identify whether there is data to be transmitted between the upper node and the at least one lower node, transmitting, by the upper node, information required for data transmission to the at least one lower node based on the report request and response, and transmitting and receiving, by the upper node, data to and from the at least one lower node based on the information required for data transmission.

Abstract: A wireless sensor network and data transmission method thereof provides for improving channel access efficiency and energy saving effect by using inventive carrier sensing mechanism. The data transmission method includes assessing a channel after initializing, when a packet to be transmitted is generated, a number of carrier sensing attempts (Ns) and a backoff value (W); determining, when the channel availability is assessed to be idle, whether W reaches 0; transmitting the packet if W reaches 0; and reassessing, if W does not reach 0, the channel after a duration corresponding W/(Ns-1) slot.

Abstract: A communication terminal and method is provided for improving channel utilization efficiency in a wireless sensor network using contention-based channel access mechanism is disclosed. The communication method according to the present invention comprises initializing, when a packet transmission is required, a contention window to a size; resetting, when a channel is assessed to be busy, the size of the contention window in a hybrid expansion mode; and attempting, when the channel is assessed to be idle, the packet transmission through the channel.

Abstract: A wireless sensor network and management method for same are disclosed. The wireless sensor network includes a plurality of nodes transitioning between a sleeping state, probing state, and working state. The management method enables the nodes to make a state transition according to sent and received messages.

Abstract: A method for performing communication in the wireless sensor network is disclosed. The upper node transmits a beacon message to the lower nodes, wherein the beacon message distinguishes an indirect transmission interval, in which the upper node transmits downlink data to the plurality of lower nodes, from a direct transmission interval adjacent to the indirect transmission interval, in which the upper node receives uplink data from the plurality of lower nodes. The lower nodes determine the indirect transmission interval and the direct transmission interval from the received beacon message. The downlink data is transmitted from the upper node to the lower nodes in the indirect transmission interval. The uplink data is transmitted from the lower nodes to the upper node in the direct transmission interval. When communication is performed between the upper node and the lower nodes, the data can be efficiently transmitted from the upper node to the lower nodes.

Abstract: A packet transmission method for a WPAN that for alleviating traffic concentration in an active period and improving network throughput by controlling packet transmission timing in the active period. A packet transmission method for a wireless personal area network including a coordinator operating with a specific duty cycle and a plurality of devices includes determining, when a packet is generated, whether there is another packet waiting to be sent; determining, if there is no other packet waiting to be sent, whether the network is in an inactive period; setting, when network is in an inactive period, a backoff time; and sending the packet when the backoff time has expired. The packet transmission method controls an initial backoff value adaptively to a duty cycle of the network.

Abstract: A wireless sensor network system and a cluster management method thereof. The wireless sensor network system includes at least one cluster having at least one sensor node for collecting sensing data, and a cluster head for aggregating the sensing data from the at least one sensor node. A sink node collects the aggregated sensing data from the at least one cluster, wherein the cluster head of a first cluster determines a cluster size of the first cluster, and when the first cluster is a master cluster and the cluster size of the first cluster is less than a threshold size, merges, the first cluster into a second master cluster, and switches the first cluster to a slave cluster. In each cluster, management efficiency can thereby be maintained within a specified range, and the lifetime of a wireless sensor network can be prolonged by reducing energy consumption.

Abstract: A method for generating a superframe structure by using a beacon scheduling within a wireless sensor network and transmitting data based on the generated superframe structure includes: defining, by each of a plurality of data transceivers in the network, a relation with data transceivers located in their vicinity; assigning a data transceiver for beacon transmission/reception to each slot of a superframe in consideration of the defined relation; generating a superframe structure including a Beacon Only Period (BOP) and a data frame transmission period, in consideration of assigned slots; and broadcasting beacons and data frames in consideration of the superframe structure.

Abstract: A channel allocation control method in a wireless mesh network system in which an adaptive channel allocation is possible, including: determining whether an Ad-hoc Traffic Indication Message (ATIM) packet is received from a transmission node during an ATIM window period after transmission of a beacon; determining whether a received point in time of the ATIM packet is a termination point in time of the ATIM window period when the ATIM Packet is received from the transmission node as a result of the determination; setting an ATIM unit period for a channel negation time of a received node when the received point in time of the ATIM packet is the termination point in ATIM window period as a result of the determination; and terminating the ATIM window after performing the channel negation with the transmission node that transmitted the ATIM packet. The improved wireless mesh network systems also are disclosed.