Abstract: An apparatus and a method for performing a protocol that optimizes a transmission power in a network. The apparatus and the method perform a protocol that optimizes the transmission power in the network for point-to-multipoint communication (1:N). The apparatus includes a communication unit for sending and receiving a data packet through the air, and a control unit that outputs a control signal for controlling the transmission power according to connection information of the data packet received through the communication unit. The connection information includes a reception signal strength and/or link quality information. Since the transmission power is adjustable, communication is carried out among nodes of the network with an adequately minimum power consumption and a proper communication quality.

Abstract: An apparatus and a method for performing a protocol that optimizes a transmission power in a network. The apparatus and the method perform a protocol that optimizes the transmission power in the network for point-to-multipoint communication (1:N). The apparatus includes a communication unit for sending and receiving a data packet through the air, and a control unit that outputs a control signal for controlling the transmission power according to connection information of the data packet received through the communication unit. The connection information includes a reception signal strength and/or link quality information. Since the transmission power is adjustable, communication is carried out among nodes of the network with an adequately minimum power consumption and a proper communication quality.

Abstract: An apparatus and a method for performing a protocol that optimizes a transmission power in a network. The apparatus and the method perform a protocol that optimizes the transmission power in the network for point-to-multipoint communication (1:N). The apparatus includes a communication unit for sending and receiving a data packet through the air, and a control unit that outputs a control signal for controlling the transmission power according to connection information of the data packet received through the communication unit. The connection information includes a reception signal strength and/or link quality information. Since the transmission power is adjustable, communication is carried out among nodes of the network with an adequately minimum power consumption and a proper communication quality.

Abstract: A method for managing a network in which Bluetooth equipped devices are linked together when the network master cannot serve as a master. During normal operation, the network master updates the backup master rank information when the network master disappears, in a predetermined cycle, according to link information, such as received signal strength indication (RSSI) or link quality, transmitted from the Bluetooth equipped devices serving as a slave. When power of the network master is exhausted, or when the network master leaves the network operating region, a new master is selected from the remaining slaves according to the backup master rank information, thereby reconfiguring a network around the new network master. The method enables proper designation of a new master when a preexisting network master leaves the network operating region, thereby increasing a probability of holding connection throughout the network.

Abstract: A mobile radio frequency identification (mRFID) reader having a receiving circuit is provided. The receiving circuit includes a local oscillator which generates a carrier signal at a predetermined frequency band; a mixer which mixes a tag signal received from a tag with the carrier signal, to lower a frequency of the tag signal; a phase adjusting block which adjusts a phase of the carrier signal by determining a phase of the tag signal; and a control block which processes the tag signal through a series of operations, and controls an operation of the phase adjusting block to compensate for a phase delay of the tag signal according to an output of the processed tag signal. Because the mRFID reader can be provided as small as a half size of a related art reader, a mobile communication terminal accommodating the mRFID reader can be compact-sized. Additionally, because the number of components for the receiving circuit decreases, not only the power consumption but also the unit price can be reduced.

Abstract: Provided are an RFID reader and a data recovery method which selectively selects only an integrity-checked phase signal, when receiving a backscattered signal of an RFID tag through an I signal path or a Q signal path, and may reduce a shadow area of a read range. The RFID reader includes a signal receiver which receives a plurality of phase signals; a symbol detector which recovers data with respect to each of the received phase signals; and a signal selector which selects a signal that satisfies a predetermined standard, from the data-recovered phase signals.

Abstract: A system and method for providing geographical information to a driver of a vehicle using radio frequency identification (RFID). Also provided is a traffic information supply system using RFID. The geographical information supply system includes a reader provided near a road which outputs a first signal and receives a second signal generated in response to the first signal; a tag that senses the first signal, converts information on a destination into the second signal in response to the first signal, and outputs the second signal. Also included is a first control unit which extracts and outputs the destination information from the second signal, receives geographical information to the destination, and supplies the geographical information to a driver. A server generates the geographical information corresponding to the destination information and outputs the generated geographical information to the first control unit.

Abstract: In receiving information on an item by use of electromagnetic waves propagating from the item in which a radio frequency identification (RFID) chip is embedded, a portable handset requests the information on the item that is stored in the RFID chip to the RFID chip-embedded item, receives from the item the information on the item, and, if additional information is needed other than the received information, requests the additional information to a server storing the information on the item by using the received information.

Abstract: A single side band (SSB) response method of a radio frequency identification (RFID) tag receives a double side band (DSB) response signal whose frequency band is shifted from the RFID tag by shifting an SSB frequency band after transmitting an SSB command signal to an RFID tag. Even though the reader uses the SSB frequency band, the reader can receive a stable DSB response signal from the RFID tag.

Abstract: Disclosed is a correlation method to adaptively operate in a time varying phase and a correlator thereof. A correlation method according to the present invention includes performing the first correlation according to a certain reference value and a certain reference interval for correlation of a received signal; calculating an average variation of the received signal through the result of performing the first correlation; deciding a new reference value for the second correlation through the average variation; performing the second correlation according to the new reference value and the reference interval; and selecting the maximum value among the result of performing the second correlation. Accordingly, plural references are decided considering variation of a response signal between tags and also separate plural references are decided considering bit variation of a response signal in the same tag, so that a digital signal can be ideally demodulated in the environment where signal phase variation occurs.

Abstract: When a reader of a Radio Frequency Identification (RF-ID) system sends out a command signal to the RF-ID tag and receives a response signal from the RF-ID tag, an End of Signal (EOS) of the received response signal is detected such that the next command signal can be transmitted within a time. Accordingly, response signal can be detected even under the environment of poor signal to noise ratio performance, and the EOS of the response signal from the RF-ID tag can be recognized with ease and speed.

Abstract: A signal transmitting and receiving method in a wireless network use a reader creates a pulse width list relating to pulse widths of transmission signals; transmits signals in sequence according to the created pulse width list; and receives a reply signal with respect to the transmitted signals. The method includes creating a pulse width list relating to pulse widths of the transmitted signals; transmitting signals in sequence according to the created pulse width list; and creating an available pulse width list including a corresponding pulse width in response to receiving a reply signal from the transmitted signals; and transmitting signals in sequence according to the created available pulse width list.

Abstract: An identification (ID) anti-collision method using a data structure to be applied to a radio frequency identification (RFID) system, includes transmitting an ID transmission request command from the reader to the tags using a predetermined request value; determining whether the IDs of the tags collide with one another, based on a bit pattern transmitted from the tags; if the IDs of the tags collide, computing a next request value to be used at a next request to transmit a request command, and if the IDs of the tags do not collide, computing and storing a future request value to be used; and if the IDs of the tags do not collide, transmitting and receiving data and a tag using an ID of the tag corresponding to the bit pattern and if the requested value is stored, transmitting a request command using the stored request value.

Abstract: A reader, tags, an RFID system, and a method of simultaneously identifying a plurality of tags having colliding reply signals and reducing the reading time. In the RFID system including a reader and plural tags assigned unique IDs, the reader stores a comparison code which identifies ID codes generated based on the unique IDs of the tags, and issues a query signal to the tags to inquire into the presence of the tags. In response to the received query signal, the tags generate the ID) codes based on their unique IDs and sends the ID codes to the reader. The reader stores the received ID codes and identifies the responding tags by comparing the stored comparison code with the ID codes. When the ID codes are orthogonal, colliding reply signals can be resolved through a correlation technique.

Abstract: A channel selection method for reading tag information, a channel selection apparatus of an RFID reader applying the same, and an RFID reader. A channel selection apparatus of a radio frequency identification (RFID) reader equipped within a wireless communication portable terminal, includes a channel selection unit which selects a channel to read tag information stored in an RFID tag, and a channel determination unit which, when determining that the selected channel is not used by another RFID reader, determines the selected channel to be a channel to read the tag information. Accordingly, when a plurality of RFID readers reads out the tag information from the RFID tag almost at the same time, the interference among them can be avoided.

Abstract: An anti-collision method is provided for a radio frequency identification (RFID) system including a reader, and two or more tags each having an ID. The anti-collision method includes transmitting an ID request value from the reader to the respective tags, the ID request value containing one or more of the codes forming the ID, receiving the ID from at least one of the tags which contain the ID request value, when a plurality of IDs collide, requesting the tags for a value representing a position of collision, and receiving the value representing the position of collision from the tags and identifying the IDs of the tags. Because collision pattern of the bits of respective IDs is recognized, and a plurality of IDs are recognized, the number of transmissions between the reader and the tags can be reduced.

Abstract: A system for protecting signal emitting tag related information and a method thereof are provided. The method of protecting the signal emitting tag related information includes operations of receiving a request for the signal emitting tag related information, which is information related to a the signal emitting tag, and providing the requested signal emitting tag related information after authenticating the request. Therefore, a non-permitted user can be prevented from reading the signal emitting tag related information so that the signal emitting tag related information can be protected.

Abstract: A radio frequency identification (RFID) reader for offering tag related information and a method thereof are provided. The RFID reader includes a communicator which receives a radio frequency (RF) signal from an RFID tag, a controller which calculates location information of the RFID tag on the basis of the RF signal, and a display information generator which processes the location information of the RFID tag to be displayed on a display. Accordingly, even when a plurality of RFID tags are located around the reader, a user can identify the RFID tags with the identifications (IDs) of the RFID tags read by the reader.

Abstract: A radio frequency identification (RFID) tag and a RFID reader for anti-collision, and an operation method thereof are provided. The RFID tag includes a tag receiving part for receiving a tag recognition signal from a RFID reader, a tag transmitting part for transmitting a response signal and a tag data in response to the tag recognition signal, a mode switching part for switching current mode into a predetermined mode, and a controlling part for causing the predetermined mode to be switched by the mode switching part, when the response signal is transmitted by a predetermined number of times by the tag transmitting part. Accordingly, when a few number of RFID tags are used, collision of tag data can be prevented at the RFID reader, and the RFID tags are rapidly recognized.

Abstract: A mobile radio frequency identification (RFID) reader, a portable terminal having the same, and an RF transmission (Tx) power setting method thereof. The RF Tx power setting method includes selecting an RF Tx power of an RF Tx power which is used to read tag information from an RF identification (RFID) tag; and setting the selected RF Tx power to a Tx power of the RF Tx signal. Accordingly, since it is possible to variably set the Tx power of the RF Tx signal used to read out the tag information from the RFID tag, the power consumption can be reduced at the RFID reader or the portable terminal equipped with the RFID reader.