Patent application number | Description | Published |
20090129353 | METHOD FOR RECOGNIZING AVAILABLE CHANNEL IN IEEE 802.15.4 PROTOCOL CSMA/CA MECHANISM - Disclosed is a method of recognizing an available channel in order to prevent channel occupation requirements from colliding with each other when one wireless channel is shared by plural terminals in a CSMA/CA mechanism using an IEEE 802.15.4 protocol slot, the method including: a first step of initializing a counter, CW, as 2, the CW being used for CCA which an attempt to perform is made before frame transmission; a second step of determining if a required channel is occupied; a third step of decreasing the CW by 1 when the channel is idle in the second step; a fourth step of re-determining if the channel is occupied; and a fifth step of, based on a determination result in the fourth step, determining if the CW is 1 when the channel is occupied. | 05-21-2009 |
20090190566 | METHOD AND APPARATUS OF CONTROLLING ACCESS MODE FOR COMMUNICATION SYSTEM USING SHARED OR UNLICENSED BAND - A technology that can adaptively control an access mode according to a shared band or an unlicensed band used by an adjacent communication system. An access mode controlling apparatus includes a band recognition unit to recognize a usage rate of an unlicensed band or a shared band that is used by an adjacent communication system of a target communication system; a mode determination unit to determine, as an access mode, any one of a contention access mode and a contention-free access mode, based on the usage rate of the unlicensed band or the shared band; and an information transmitter to transmit mode information associated with the determined access mode to member nodes or a base station of the target communication system. | 07-30-2009 |
20100067455 | METHOD FOR FRACTIONAL FRQUENCY REUSE WITH ORDERING SCHEME TO INCREASE CAPACITY OF OFDM SYSTEMS - Disclosed herein is a method for fractional frequency reuse with ordering scheme (FFRO) to increase capacity of orthogonal frequency division multiplexing (OFDM) systems while reducing interference due to the use of a common sub-channel set. Each cell includes a common sub-channel set assigned in common to all cells provided in a cluster and a dedicated sub-channel set assigned differently to all of the cells. The method includes classifying the cells into at least one type according to cluster sizes, and allocating the dedicated sub-channel set by frequency partitioning scheme based on the cell type. | 03-18-2010 |
20110032864 | METHODS OF PERFORMING COOPERATIVE COMMUNICATION IN WIRELESS LANs - Method of performing cooperative communication in wireless LAN includes determining, by receiver, whether cooperative communication is necessary based on transmission request signal provided from transmitter, when it is determined that the cooperative communication is necessary, transmitting, by the receiver, transmission response signal instructing the cooperative communication, overhearing, by a plurality of devices, the transmission response signal instructing the cooperative communication, transmitting, by at least one of the devices, response signal for supporting relaying to the transmitter, selecting, by the transmitter, a relay based on the response signal, transmitting, by the transmitter, data to the relay, and attaching, by the relay, data of the relay to the data transmitted by the transmitter and transmitting result data to the receiver. Thus, average transmission rate of wireless LAN can be improved with minimized overhead, and additional transmission opportunity can be provided to relaying device, thereby properly rewarding relaying device. | 02-10-2011 |
20130093571 | ANTI-COLLISION SYSTEM AND METHOD FOR REDUCING THE COLLISION OF DATA TRANSMITTED BY RFID TAGS - Provided are an anti-collision system and method which address the mobility of radio frequency identification (RFID) tags. An RFID reader may transmit an identification start command to identify a plurality of RFID tags in an identification area of the RFID reader. The RFID tags compare the number of collisions of each RFID tag receiving the identification start command with a collision threshold C | 04-18-2013 |
20140098776 | APPARATUS AND METHOD FOR SELF-SCHEDULING IN A WIRELESS COMMUNICATION SYSTEM - The present disclosure provides channel sensing in an efficient manner in a cognitive radio MAC protocol and improves channel utilization. Proposed is an Adaptive Channel Sensing (ACS) for variably sensing a channel in accordance with a Fixed Channel Sensing (FCS) and a channel state so as to perform the channel sensing in an efficient manner while reducing the power consumption of a terminal Further proposed is a self-scheduling mechanism which enables multiple terminals to simultaneously transceive data by means of a slot-based contention on the basis of the results of the FCS and ACS, which are proposed by the present disclosure. | 04-10-2014 |
20140146803 | NETWORK BROADCAST METHOD USING UNICAST AND RELAY NODE - A network broadcast method using a MAC unicast and an MPR node allows a source node to transmit a data packet to at least one MPR node which is located within one-hop distance from the source node and allows the at least one MPR node to transmit the data packet to each next-ranked MPR nodes. At least one normal node, which is not an MPR node while being located within one-hop distance from the source node, receives the data packet of the source node, which is transferred from the source node to an MPR node or transferred between MPR nodes through overhearing. Although the source node and MPR nodes are in a hidden-node relationship, collision is prevented, thereby minimizing data packet loss to improve the transmission reliability, and enabling the data packet of the source node to be reliably broadcasted on a network. | 05-29-2014 |
20140321305 | WIRELESS NETWORK, ACCESS POINT, AND TERMINAL - Wireless network, access point, and terminal are disclosed. A method for determining a size of an access window performed in an access point in a wireless network may comprise estimating a number of terminals attempting to access uplink (hereafter, uplink access attempt terminals) in a first access window including at least one uplink slot which is allocated to the terminal or is randomly selected by the terminal so as to transmit uplink data; and determining a size of a second access window next to the first access window based on the estimated number of the uplink access attempt terminals. | 10-30-2014 |