Abstract: 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.

Abstract: Provided are a sensor node and method for a preamble sampling, and an apparatus and method for computing a preamble interval. A transceiver may verify a number of neighboring nodes positioned in a sensor network, and a sampling unit may perform the preamble sampling using a sampling duration that is set based on the number of neighboring nodes.

Abstract: Provided are a communication method and system for sensor network. In reporting event occurrence in a real-time sensor network application, a cycle time is divided into an event announcement period and a data transmission period to provide real-time transmission performance and energy efficiency. Each of the periods is again divided into the number of slots equal to the maximum depth of a network. Respective nodes sequentially operate according to their depths in a routing tree during the event announcement period to receive the signal transmitted from the lower node. To remove sleep delay, a slot next to the signal reception slot becomes a signal transmission slot. A node sensed an event transmits a signal informing event occurrence during its signal transmission slot, and this signal includes only the address of the transmission node. When a signal does not exist in the event announcement period, no traffic occurs in the data transmission period and the upper nodes maintain a sleep state.

Abstract: 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.

Abstract: Provided are an apparatus and method for asset tracking based on a ubiquitous sensor network (USN) using a motion sensing. The apparatus may include: a motion sensing manager to receive motion sensing information from a sensor; a filtering processor to filter the motion sensing information based on a filtering parameter and to determine whether a motion occurs based on the filtered motion sensing information; and a location information update (LU) manager to perform LU depending on whether the motion occurs.

Abstract: 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.

Abstract: Provided is a communication apparatus and method for enhancing a reliability in a low power time division access scheme of a sensor network. The communication method may include: transmitting, by a first sensor node, a Media Access Control (MAC) frame to a second sensor node in a first time slot that is allocated to the first sensor node; and receiving, by the first sensor node, a response frame with respect to the MAC frame from the second sensor node in a second time slot that is allocated to the second sensor node.

Abstract: 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.

Abstract: Disclosed is a configuration method and device for a two-dimensional expandable crossbar matrix switch for application to tera-level high-speed and large-capacity switches. The present invention includes N input ports, N output ports, and an N×N matrix switch for transmitting cells between the input and output ports. Each input port includes N VOQs which are sequentially combined by n VOQs to configure respective L VOQ groups. The L VOQ groups are connected to L XSUs through independent interface ports. Therefore, each input port can transmit a maximum of L cells to the matrix switch during one cell time slot.

Abstract: A high speed and high capacity switching apparatus is disclosed. The apparatus includes: N input ports each of which for outputting maximum l cells in a time slot, wherein each of the N input ports includes N virtual output queues (VOQs) which are grouped in l virtual output queues group with n VOQs; N×N switch fabric having l2 crossbar switch units for scheduling cells inputted from N input ports based on a first arbitration function based on a round-robin, wherein l VOQ groups are connected to l XSUs; and N output ports connected to l XSUs for selecting one cell from l XSUs in a cell time slot by scheduling cells by a second arbitration function based on a backlog weighed round-robin, which operates independently of the first arbitration function, and transferring the selected cell to its output link.

Abstract: A high speed and high capacity switching apparatus is disclosed. The apparatus includes: N input ports each of which for outputting maximum l cells in a time slot, wherein each of the N input ports includes N virtual output queues (VOQs) which are grouped in l virtual output queues group with n VOQs; N×N switch fabric having l2 crossbar switch units for scheduling cells inputted from N input ports based on a first arbitration function based on a round-robin, wherein l VOQ groups are connected to l XSUs; and N output ports connected to l XSUs for selecting one cell from l XSUs in a cell time slot by scheduling cells by a second arbitration function based on a backlog weighed round-robin, which operates independently of the first arbitration function, and transferring the selected cell to its output link.

Abstract: Disclosed is a configuration method and device for a two-dimensional expandable crossbar matrix switch for application to tera-level high-speed and large-capacity switches. The present invention includes N input ports, N output ports, and an N×N matrix switch for transmitting cells between the input and output ports. Each input port includes N VOQs which are sequentially combined by n VOQs to configure respective L VOQ groups. The L VOQ groups are connected to L XSUs through independent interface ports. Therefore, each input port can transmit a maximum of L cells to the matrix switch during one cell time slot.

Abstract: An asynchronous transfer mode (ATM) host adapting apparatus comprising: a storage block for storing packet information, received cells, and parameters; an ATM network interface handling block for performing direct memory access of ATM cells and parameter stored therein, segmenting transmit packet information, reassembling received cells, transmitting and receiving the ATM cells to physical media cell received, and arbitrating in the direct memory access; and a secondary interface block for connecting the storage block to the ATM network interface handling block.

Abstract: A direct memory read and cell transmission apparatus for an ATM cell segmentation system having a host CPU is disclosed. The segmentation circuit of the apparatus transfers the address and size for the start of the DMA by the byte unit. When a predetermined information is provided, and a DMA read is requested, the data is transferred through the bus of the word unit such as the PCI interface, and then necessary bytes are obtained for thereby forming a 32 bit word stream, so that the ATM cell of a 32 bit×12 word form and transfers to the lower circuit. Therefore, when the segmentation circuit processes the buffer, all data are computed by the byte unit, and in an application program, the data are not obtained for transmitting the data to the ATM cell, so that it is possible to enhance the processing capability.

Abstract: The present invention relates to a broadband terminal equipment for congestion control in the ring structure and its control method, and the object of the invention is to prevent ATM traffic congestion which can be produced in the ring in order to realize the ATM subscriber premises network having a ring structure.

Abstract: A floating cell removing device using a generic flow control includes a processor having a generic flow control processing logic for transmitting/receiving a signal cell, checking a generic flow control field of an operation and maintenance cell and removing a floating cell; a pair of cell relay and add/drop function units respectively connected to a subscriber and a network of the processor, for supporting an internal communication between subscriber terminals, temporarily storing the signal cell and transmitting it to a network device; a pair of asynchronous transfer mode hierarchical function processors for converting a cell header, inserting and extracting an operation and maintenance cell, and transmitting it to the processor and the cell relay and add/drop function units; and a plurality of buffers formed between the processor and the cell relay and add/drop function units and between the cell relay and add/drop function units, for temporarily storing data inputted therefrom.