Abstract: A method and system for indoor positioning using a mobile terminal, the method including designating a plurality of virtual locations using the mobile terminal while the mobile terminal is in motion; and tracking a location of a specific terminal by performing a localization measurement communication with the specific terminal based on the plurality of virtual anchor locations.

Abstract: A location recognition system and method using stereophonic sound, the system having a transmitter and a receiver. The transmitter uses the stereophonic sound and transmits location tracking information of an object. The transmitter includes a sound detector which detects a sound of the object and converts the detected sound to an electrical signal; a data converter which converts the electrical signal converted by the sound detector, to acoustic data; and a first communication interface which transmits the acoustic data converted by the data converter and the location tracking information to the receiver. A user can immediately recognize the location of the transmitter which transmits the location tracking information and is the target of the location tracking. Therefore, the mutual communications between the transmitter and the receiver which receives the location tracking information can be smoothly carried out.

Abstract: A receiver having a low computation complexity so as to estimate a transmitted includes a likelihood function calculator calculating likelihoods of transmittable signals using a currently received signal, at least one previously received signal, and an estimated signal corresponding to the at least one previously received signal; and a maximum value output unit outputting a transmittable signal corresponding to a likelihood function of the likelihood functions having a maximum value. Thus, a currently received signal can be estimated using a previously received signal, a previously estimated signal, and the currently received signal. As a result, the reliability of the estimated signal can be improved. Also, the previously estimated signal can be stored to prevent the complexity of a computation from being increased.

Abstract: A coordinator's data transmission method, a device's data reception method, a coordinator using the coordinator's data transmission method and a device using the device's data reception method are provided. In a Zigbee system including at least one device and a coordinator for coordinating the device, in a case where a frame pending bit in a beacon frame is determined to be a value representing a direct transmission method, a beacon frame containing an address of a device to receive data and a data transmission time is generated and data is transmitted from the coordinator at the data transmission time. Data transmission time and power consumption can be reduced.

Abstract: A beacon scheduling method and system in a network system. The beacon scheduling method of a router in a network system that includes at least one router, includes receiving a beacon signal from a parent node; calculating a difference between an address of the parent node and an address of the router; and setting the calculated difference to a beacon transmission offset of the router. Accordingly, all devices from the top to the bottom of the network can transmit their beacons without collisions, and thus the multi-hop tree structure can be established.

Abstract: A method for flooding a route request packet that is received at a node in a communication system constructed of at least three nodes including a source node that requests to establish a route and a destination node that receives the route request. One of a plurality of levels having different transmission periods is determined using a strength of a received signal of a measured packet. A transmission start point is selected at the determined level, and it is determined whether a route request packet is re-received before the selected transmission start point. The received packet is broadcast at the selected transmission start point when the packet is not re-received. The transmission start point is randomly selected within the transmission period or at the level in consideration of the number of the connected nodes.

Abstract: The present invention is a wireless media access method on a wireless network synchronized by a synchronizing signal broadcasted from a coordinator. In the method, priority is assigned to a plurality of devices interconnected over the wireless network for securing wireless resources in accordance with application characteristics of a packet to be transmitted, and if the devices request communication, dividing at least one slot within a superframe into a plurality of minislots. Minislots are then allocated to the devices, respectively, according to the priority, and information about the allocated minislots is inserted into the synchronizing signal. The information is then broadcast, thereby allowing each of the devices with the allocated minislots to exclusively use the allocated minislot for data communication.

Abstract: A wireless communication apparatus and method for voice communications in the wireless personal area network. The present wireless communication apparatus and method is applied to a network environment to which plural devices are connected and which is synchronized by a synchronization signal broadcast from any of the plural devices. In such a network environment, the present invention includes allocating time slots for the voice communications between first and second devices of the plural devices, inserting information on the allocated time slots to the synchronization signal, and broadcasting the synchronization signal to the plural devices; sending and receiving voice data between the first and second devices to and from the allocated time slots; and releasing the allocated time slots if the sending and receiving of the voice data is terminated. Through such a wireless communication, the voice communications can be achieved in the personal area network environment based on the IEEE 802.15.4 standard.

Abstract: A control packet management device of a packet forwarding system has a packet queue having a plurality of queues to store a control packet as transmitted, a first processor to transmit said control packet stored in one queue of said plurality of queues to a host a by one-to-one interrupt, a second processor to divide said control packets stored in said one queue into groups of a predetermined size and transmit said control packets to said host in the group unit and by direct memory access (DMA), a third processor to discard a most common type of said control packets stored in said one queue, and a controller to control said first, second and third processors to selectively operate in accordance with an accumulation state of said control packets stored in said plurality of queues.

Abstract: An apparatus and method of processing protocols and traffic are disclosed. An assembling and segmenting portion assembles input cells to generate data packets and segments the data packets to regenerate the cells. A lower layer protocol processing portion processes lower layer protocols of sub-data packets extracted from a packet extracting portion. A higher layer protocol processing portion divides the sub-data packets into major packets and minor packets and processes them adaptively. Accordingly, traffic and protocols can be processed in a network system in which a master system and a plurality of slave systems are combined. Therefore, the size of the network system can be smaller.

Abstract: A system for accessing a node of a private network includes an assigning portion for assigning external port values to respective network nodes based on information collected from the network nodes of the private network, and storing the assigned external port values; an exchanging portion for exchanging the external port values of the respective network nodes of private networks; and an address converting portion for converting the external port values into corresponding private IP addresses and internal port values when a network node of one private network accesses another network node of another private network by using the external port values of another network node of another private network. Accordingly, a network node of a private network without a global IP address becomes accessible.