Abstract: A system and method for controlling congestion using Request-to-Send (RTS) and Clear-to-Send (CTS) in a wireless mesh network are provided. A receiver in a congestion state sets a duration field value of congestion control in a CTS frame and transmits the CTS frame to a sender. In response, the sender retransmits an RTS frame to the receiver without transmitting data, after waiting for an RTS retransmission waiting time period corresponding to the duration field value. The congestion state information is broadcast to neighboring nodes. Therefore, the congestion control system using the CTS frame does not use a separate frame for the congestion control. And, all of the neighboring nodes can participate in the congestion control, increasing the network efficiency.

Abstract: A method and apparatus are provided for receiving data in a wireless local area network (WLAN) communication system, where a first control signal to check if it is possible to receive data is received, and, when it is possible to receive data, waiting for data and when it is impossible to receive data, transmitting a second control signal representing data reception impossibility. Herein, the second control signal comprises information that enables data transmission when a second control signal is not received during a time interval.

Abstract: An apparatus and a method are provided in a wireless local area network mesh communication system having one wireless interface and multi-channels for improving the performance of the WLAN mesh communication system. A transmitter and a receiver are set to use different channels respectively. A first channel is assigned as a dedicated channel for transmitting data frames and a second channel is assigned as a common channel which receives a control frame, while transmitting the data frames through the first channel. Thus, the control frame is received, while transmitting the data frames, to obtain information relating to the channels which are not already in use and to effectively use the channels, thereby improving the capacity of the network.

Abstract: A method and system for transmitting and receiving a signal between first and second mobile nodes is provided. The method and system offers improvements to the throughput of an overall wireless local area network. When the first mobile node receives a data frame from the second mobile node, third mobile nodes can also transmit and receive the data frame. The first mobile node sends an acknowledgement (ACK) frame for notifying that the data frame has been completely received to the second mobile node through a common channel.

Abstract: A multi-channel scheduling method in a wireless network is provided. The wireless network includes a plurality of Wireless Local Area Network (WLAN) devices with a single radio interface. A regular time interval P and a Channel Coordination Window (CCW) to be repeated in a period of P are set. A request is made such that the plurality of devices are tuned to a first channel at a start point of the CCW. A pair of arbitrary WLAN devices among the plurality of WLAN devices is allowed to transmit control frames in the regular time interval P. The control frames are a transmission proposal control frame for proposing communication in a second channel and a response frame, responding to the transmission proposal control frame, for indicating whether the second channel has been accepted or rejected. The arbitrary WLAN devices of the pair are switched to the second channel after acceptance.

Abstract: A method to transfer a plurality of data stored in a memory using one instruction. In a memory including at least two regions to which the addresses are assigned respectively, data are allocated to the addresses in sequence, and the allocated data are transferred using one instruction. At least one block is generated, which transfers data using one instruction, and it is instructed to include the data in the at least one block. The data in the block are linked with each other, and the number of paths linking two data is calculated with respect to the at least one block. The data are linked using shortest paths in consideration of the number of the linking paths, and the data are allocated by the addresses using the shortest paths.

Abstract: An apparatus and method for recording/reproducing voice messages using an internet gateway without separately procuring a VMS (Voice Mailing System). Upon receiving the voice message from a subscriber, the voice message is compressed in a data compressor of a digital signal processor (DSP) and stored in a flash memory. Then, the voice message is stored in a buffer of the DSP at a predetermined time interval, and subsequently read and decompressed by a data decompressor, and thereafter reproduced to a calling subscriber.

Abstract: A packet forwarding system to transfer packets through a plurality of interfaces by reading out information for the packet forwarding beforehand includes a packet processor that organizes and processes data to be transferred into packets, a packet memory storing the organized packets, a plurality of interfaces respectively transferring the packets stored in the packet memory depending on destinations of the packets, and a packet forwarding manager managing an packet information to transfer the packets through the plurality of the interfaces, respectively, and to control transfer of the packets immediately through a corresponding interface of the plurality of the interfaces by reading out the packet information before the packet forwarding. Accordingly, the fast packet forwarding is realized by processing the packet information read and the actual packet forwarding in parallel.

Abstract: A method for receiving packets from a network and distributing the packets to corresponding protocol processors, includes determining whether a received fragmented packet is a first fragment; if the received packet is the first fragment, looking-up its tunnel ID and its fragment ID, and comparing the result of the looked-up fragment ID with each list of a fragment look-up table, into which the results of fragment look-ups on received packets are entered, to determine if there is a corresponding list; searching an index corresponding to the tunnel ID of the received packet from a tunnel ID look-up table, and if the list conforming to the result of the looked-up fragment ID exists in the fragment look-up table, entering the index into the corresponding list of the fragment look-up table; and attaching the index as a tag to the received packet and transmitting the received packet to the corresponding protocol processor.

Abstract: An object-based quad-tree mesh motion compensation method using the Greedy algorithm is provided. This method defines an object-based quad-tree mesh structure defined by extending a hierarchical grid interpolation technique, by which complicated or partial motion is more accurately displayed, so that it is suitable for an object-based technique. Also, this method provides a quad-tree block segmentation method using the Greedy algorithm by which the transmission rate-distortion performance of motion compensation is improved. The object-based quad-tree mesh motion compensation method using the Greedy algorithm, includes (a) defining an object-based quad-tree mesh, (b) segmenting each block in an image frame, which is segmented into blocks of predetermined sizes, in order to form the object-based quad-tree mesh of the step (a), and (c) estimating the motions of vertices to minimize distortion during compensation of motions within the segmented block, and compensating for the motion of an image within the block.