Abstract: An UpLink (UL) scheduling method and apparatus considering a characteristic of a power amplifier in a mobile communication terminal are provided. The UL scheduling method includes calculating a packet transmission time, which minimizes energy consumed in packet transmission, by using a Direct Current (DC) voltage used in a power amplifier for signal amplification and by using nonlinear amplification efficiency; and scheduling UL data by using the calculated packet transmission time.

Abstract: Disclosed is a method for detecting a hidden station in a specific station constituting a wireless communication network that includes receiving a frame after a lapse of an idle state interval longer than a predetermined waiting time; determining that there is a hidden station, if a size of the received frame is equal to a size of an Acknowledge (ACK) frame; and determining that there is no hidden station, if the size of the received frame is not equal to the size of the ACK frame.

Abstract: Provided are a system and method of transmitting an Aggregated Media Access Control (MAC) Protocol Data Unit (A-MPDU) in a Wireless Local Area Network (WLAN) system. A MAC layer divides service data transferred from an upper layer into a plurality of MPDUs, forms a single transmission frame including the sequentially arranged MPDUs, delimiter information for distinguishing each of the MPDUs, and ACK request information for requesting for a reception result of the MPDUs, and transmits the formed transmission frame to a recipient. Accordingly, service coverage is extended, and a transmission delay is minimized, resulting in improved service efficiency.

Abstract: An apparatus and method for controlling transmission rate by determining whether a data transmission failure is caused by a channel error or a data collision in order to reduce a collision-caused rate decrease or a collision-caused rate increase delay in a WLAN. A collision-caused data transmission failure and if the number of data transmission failures reaches a predetermined threshold, data is retransmitted by means of an RTS/CTS exchange.

Abstract: A Cognitive Radio (CR) communication apparatus is provided. The CR communication apparatus may include a determination unit to determine any one of a plurality of Radio Access Technologies (RATs) as a temporary control RAT, an estimation unit to estimate an available resource and a channel state of each common RAT using the temporary control RAT, and a selection unit to calculate an available capacity of each of the common RATs using the available resource and the channel state, and to select an optimum RAT from the common RATs based on the available capacity of each of the common RATs. The common RATs may be used by the CR communication apparatus and a receiving CR communication apparatus from among the plurality of RATs.

Abstract: A method and apparatus for adjusting the transmission power level or transmission data rate between a plurality of stations located within the coverage area of a basic service set (BSS) or in an independent basic service set (IBSS) in a wireless local area network (WLAN). The receiving station extracts a transmission data rate from an incoming signal, determines a signal-to-noise ratio (SNR) for the incoming signal, and then calculates noise margin information based on a difference between the SNR of the incoming signal and a minimum SNRMIN for the extracted data rate. The noise margin is then transmitted back to the original transmitting station and using the noise margin information, the transmit power level and/or the transmission rate of this station may be adjusted accordingly.

Abstract: Disclosed is a method for detecting a hidden station in a specific station constituting a wireless communication network that includes receiving a frame after a lapse of an idle state interval longer than a predetermined waiting time; determining that there is a hidden station, if a size of the received frame is equal to a size of an Acknowledge (ACK) frame; and determining that there is no hidden station, if the size of the received frame is not equal to the size of the ACK frame.

Abstract: Disclosed is an apparatus and method for managing resources in a mobile communication system. The method includes classifying an overall frequency band into a plurality of segment types defined in time and frequency domains by considering a channel condition between a mobile station and the base station and a QoS level required by the mobile station, if data to be transmitted is data to be transmitted in real time, allocating the data to real-time type segments in such a manner as to satisfy a minimum QoS level for the data, and when there are real-time data remaining after allocating the data, and non-real-time type segments for allocating data to be transmitted in non-real time, diverting and allocating the real-time data to the non-real-time type segments.

Abstract: The present invention relates to a method for performing fast channel switching in a wireless local area network (WLAN). The method generally includes the steps of: determining that the wireless medium has been idle during a PCF interframe space (PIFS) period, transmitting a first management frame during a slot time following the PIFS period; wherein the transmission at said slot time substantially guarantees priority access said wireless medium; and performing fast channel switching in the network in accordance with directives contained within the management frame. Fast channel switching as defined herein includes one of quieting the current channel and/or switching from a current channel of operation to a new channel of operation. The method overcomes the latencies associated with contention based services, such as the DCF service.

Abstract: Expected channel occupancy time is a wireless link metric determined based on a transmission protocol to be used for transmitting data in a wireless network. The wireless link metric may be used for routing or other network management functions. For determining the wireless link metric, an overhead is determined for one or more of accessing and releasing a channel to transmit a burst, including at least one frame, in the wireless network using the transmission protocol. An expected burst transmission time is calculated based at least on the overhead. The expected channel occupancy time is determined from the expected burst transmission time and an estimation of a number of frames to be successfully delivered during the burst.

Abstract: A channel quieting/measurement request element is provided for use in a wireless local area network. The unified element of the invention integrates a dual capability for performing channel quieting and for making measurement requests of one or more stations in the network. According to another aspect of the invention, a conventional channel quieting element is modified to include provisions for defining an offset time and an offset duration interval for performing channel quieting.

Abstract: In retransmitting data at high speed by a PHY layer in a mobile communication system, when data to be transmitted to the receiver is received from the MAC layer of the transmitter, the PHY layer of the transmitter transmits the data to the PHY layer of the receiver, receives first information representing normal reception or abnormal reception of the data from the PHY layer of the receiver, notifies the MAC layer of the transmitter of the normal reception of the data when the first information represents the normal reception, and retransmits the data to the PHY layer of the receiver when the first information represents the abnormal reception.

Abstract: Disclosed are a base station and mobile station to adaptively control a bandwidth of a channel. The base station includes a state information recognition unit to recognize neighboring-state information related with a traffic load of at least one neighboring network adjacent to a target network, a control state information transmitting unit to transmit control state information related with the controlled bandwidth of the target channel to mobile stations of the target network, and a bandwidth control unit to control a bandwidth of a target channel used in the target network according to a bandwidth of a channel used in the neighboring network based on the neighboring-state information.

Abstract: A cognitive radio terminal device. The cognitive radio terminal device comprises an available radio resource determination unit to determine an available radio resource from among up-link radio resources assigned to an up-link communication in a primary network, and an ad hoc communication performing unit to perform an ad hoc communication in a secondary network by using the available radio resource.

Abstract: A local area network is provided where an OFDM station and DSSS/CCK station coexist. During a contention-free period both stations operate under the point coordination function rules as defined in the IEEE 802.11 specification. Both stations transmit data when polled by the access point. The contention-free period comprises a sub-contention period during which only the OFDM station communicate. During the sub-contention period the OFDM station operates under the distributed coordination function while the DSSS/CCK station waits to be polled by the access point before starting to communicate.

Abstract: This invention discloses a set of internal signaling (i.e., management primitives) to support a clock-synchronization protocol for wirelessly synchronizing clock registers of wired or wireless nodes via a wireless local area network (i.e., 802.11 network). The clock synchronization is performed between two higher-layer protocol entities residing within two different wireless stations (STAs).

Abstract: An UpLink (UL) scheduling method and apparatus considering a characteristic of a power amplifier in a mobile communication terminal are provided. The UL scheduling method includes calculating a packet transmission time, which minimizes energy consumed in packet transmission, by using a Direct Current (DC) voltage used in a power amplifier for signal amplification and by using nonlinear amplification efficiency; and scheduling UL data by using the calculated packet transmission time.

Abstract: Expected channel occupancy time is a wireless link metric determined based on a transmission protocol to be used for transmitting data in a wireless network. The wireless link metric may be used for routing or other network management functions. For determining the wireless link metric, an overhead is determined for one or more of accessing and releasing a channel to transmit a burst, including at least one frame, in the wireless network using the transmission protocol. An expected burst transmission time is calculated based at least on the overhead. The expected channel occupancy time is determined from the expected burst transmission time and an estimation of a number of frames to be successfully delivered during the burst.

Abstract: A wireless communication system includes at least one AP assigned with a unique MAC address and a shared virtual MAC address; and at least one mobile station to search the at least one AP, receive AP information from the retrieved AP, and perform a handoff, wherein the mobile station transmits query data to the shared virtual MAC address, receives response data from the AP, determines whether the AP exists on a predetermined channel, and when the AP exists on the channel, requests the AP having the shared virtual MAC address for AP information, and receives the AP information from the AP.

Abstract: A method and system for determining the transmission rate between a plurality of stations in a wireless local area network (WLAN) are provided. Each mobile station evaluates the current link condition based on the Received Signal Strength (RSS) from received frames and adjusts a new transmission rate according to predetermined criteria, which is updated based on whether the transmission of subsequent signals is successful.