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.

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: A local-area network is provided where a plurality of OFDM stations and DSSS/CCK-only stations coexist. A beacon signal having a contention-free-period (CFP) is transmitted from an access point to the plurality of stations. The OFDM-modulated data is transmitted to the plurality of stations before the CFP ends, and after the CFP period ends, the DSSS/CCK-modulated data is transmitted, thereby preventing collisions between the stations.

Abstract: An apparatus and method for improving the signal reception of a digital wireless receiver comprises a processing circuit for processing the preamble information of incoming signals, wherein a first predetermined portion of the preamble information is applied to a first antenna and a second predetermined portion of the preamble information is applied to a second antenna to produce a plurality of processed signals, such that the plurality of processed signals is compared to a predefined preamble sequence to obtain a mean-square error (MSE) for the respective antenna. Then, one of the first and second antennas with a lower MSE is selected to receive and process the incoming signals.

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: A granted TxOP holder transmits the first frame of a QSTA-to-QSTA communication at a power level sufficient to ensure correct reception by the destination and at least detection by the HC, and then, with exceptions, transmits subsequent frames at a power level merely sufficient to ensure correct reception by the destination, regardless of reception or detection by the HC. Subsequent frames that must be received by the HC, such as those changing the TC queue size or requesting extension of the current TxOP, are transmitted at a power sufficient to ensure reception by the HC as well as the destination, as are the last frame(s). The HC is constrained from reclaiming the channel unconditionally merely because of failure to detect activity, and recovery is limited to the TxOP holder.

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: 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 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: An apparatus and method is disclosed for providing recovery and backoff rules for a hybrid coordinator of an IEEE 802.11e Quality of Service (QoS) wireless station. The invention comprises a wireless local area network that is capable of using the recovery and backoff rules of the present invention in the Medium Access Control (MAC) layer of QoS hybrid coordinators. The HC recovery and backoff rules of the present invention minimize collisions especially when hybrid coordinators from an overlapping basic service set are present.

Abstract: Disclosed is a method and system for dynamically selecting a communication channel between an access point (AP) and a plurality of stations (STAs) in an IEEE 802.11 wireless local area network (WLAN). The method includes the steps of: determining whether a new channel to be used by the plurality of STAs is needed; measuring the channel quality of a plurality of frequency channels by at least one of the plurality of STAs; reporting the quality of the plurality of frequency channels in terms of a received signal strength indication (RSSI), Clear Channel Assessment (CCA) busy periods and periodicity; and, selecting one of the candidate channels based on the channel quality report for use in communication between the AP and the plurality of STAs.

Abstract: The present invention is related to a medium access control (MAC) protocol for avoiding collisions among ESTAs when two or more overlapping basic service sets (OBSSs) co-exist and operate in the same channel. To achieve this, each mobile station operating under HCF maintains a first counter known as Network Allocation Vector (NAV) and a second counter known as Overlapping Network Allocation Vector (ONAV), which is updated within a mobile station by frames coming from OBSSs, during the Contention Free Period (CFP) or during a Contention Free Burst (CFB) granted by a polling frame. The mobile station uses the NAV to update only to the medium occupancy in its own BSS to ensure that the mobile station will not interfere with the transmissions in its own QBSS, while the ONAV is used to avoid collisions with the mobile stations from the OBSS.

Abstract: A power saving method of a terminal in a wireless communication system including an access point for transmitting a beacon frame and a paging frame, and a terminal for compensating for timing offset with the access point using the beacon frame and detecting a position thereof using the paging frame. The terminal supports an active mode in which data transmission/reception is actually performed and a power saving mode in which power consumption is reduced when there is no transmission/reception data. The method includes calculating a paging timing offset generated for a reception interval of the paging frame using the beacon frame, and receiving the paging frame after a lapse of a time corresponding to the paging timing offset in the power saving mode.

Abstract: An apparatus and method are provided for power management in an Independent Basic Service Set (IBSS) Wireless Local Area Network (WLAN) based on adjusting ATIM window size dynamically. In the present invention, each STA uses the gap between the last overheard Ad-hoc traffic indication message ATIM frame transmission and the end of the ATIM window to determine whether to increase or decrease the size of its ATIM window. Each STA of an IBSS competes to send its Beacon containing the size of its ATIM window and the window size of the winner is adopted by all STAs of the IBSS.

Abstract: A clock synchronization method and apparatus is disclosed for use in a communication system including a plurality of wireless nodes communicatively coupled via a wireless network, each of the plurality of wireless nodes having a local time base, and one of the plurality of wireless nodes being designated as a master node having a master time base which serves as a master clock against which the local time bases are synchronized. The clock synchronization method includes the steps of periodically transmitting synchronization frames to the plurality of non-master nodes so as to adjust the slave clocks associated with the respective non-master nodes. The synchronization frames are distributed from the master node at near-periodic intervals and includes a cycle time value that corresponds to the end of the previously transmitted synchronization frame. The slave clocks (i.e.