Abstract: The present invention relates to a method and system for enhancing the performance of the Forward-Error-Correction (FEC) scheme in a wireless local area network (WLAN). When a transmission error occurs more than a predetermined number of times using a first modulation scheme, the data transmission rate of the first modulation scheme is compared to a predetermined data rate and, if greater, the retransmission of error data is performed using a second modulation scheme.

Abstract: A local area network is provided where OFDM stations and DSSS/CCK only stations coexist. Before transmitting, an OFDM station learns of the modulation capability of an intended receiving station. If the receiving station is only capable of DSSS/CCK modulation then the OFDM station transmits DSSS/CCK modulated data. If the receiving station is capable of OFDM modulation, then the OFDM station transmits OFDM modulated data thereby enabling efficient bandwidth usage.

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: 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: 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: A method and system for combining signals in a receiver are provided. If the current packet is determined to be the retransmitted packet according to predetermined criteria, The retransmitted packet and the previously stored packet in error with the same packet number are combined using a maximum ratio combining method according to the signal-to-noise-ratio (SNR) calculated from the preamble of each packet. With this type of diversity combining, a reliable data packet transmission in a shorter time period can be obtained while increasing the SNR and reducing the throughput time in multipath channel.

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: An apparatus and method is disclosed for providing Quality of Service (QoS) signaling for an IEEE 802.11e Medium Access Control (MAC) layer in a wireless local area network (WLAN). The invention comprises a WLAN that is capable of providing three types of Quality of Service (QoS) signaling to and from wireless QoS stations in the WLAN. Upstream QoS signaling establishes a QoS stream that originates from a source wireless QoS station in the WLAN. Downstream QoS signaling establishes a QoS stream that is sent to a destination wireless QoS station in the WLAN. Sidestream QoS signaling establishes a QoS stream between a source wireless QoS station and a destination wireless QoS station in the same QoS basic service set of the WLAN.

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 system and method for providing recovery of lost payload blocks in a packet switch network in which a sequence of packets having a number of payload blocks are transmitted from a source node to a destination node. The recovery process determines whether at least one of the payload blocks within a particular packet is lost during transmission; stores other payload blocks that are successfully received within the particular packet in a storage medium for subsequent retrieval; transmits a request for retransmission of the particular packet containing said lost payload block to the source node; and, combines the stored payload blocks with the lost payload block(s) that are retrieved from the subsequent transmission in sequential order.

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: Dynamic frequency selection for an IEEE 802.11 basic service set network is enabled by a dynamic frequency selection (DFS) element within beacon and probe response frames defining a DFS owner, a DFS interval specifying the time until channel switch in beacon intervals, a DFS count specifying a time in beacon intervals until the DFS owner initiates selection of the next channel frequency from the supported channel set, and a DFS recovery interval specifying a time after the end of the DFS interval when recovery procedures are initiated if no channel switch information was received during that DFS interval. Channel switch information is presented in beacons following the end of the channel selection process, and within beacons during the DFS recovery interval.

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: A method and apparatus for determining the transmission power level between a plurality of stations located within the coverage area of a basic service set (BSS) in a wireless local area network (WLAN). The receiving station measures a received signal power from the transmitting station, then the path loss estimation is computed based on the difference between the received signal power and the transmit power level extracted from the incoming signal. The computed path loss is updated according predetermined criteria. Based on the updated path loss information, the transmit power level and/or the transmission rate of a receiving station is adjusted.

Abstract: A system and method for providing concurrent transmission in a wireless Local Area Network (WLAN) are provided. The WLAN includes a plurality of stations for transmitting information via an assigned TDM time slot, and an access point in communication with the stations for monitoring access control and providing time allocation to allow data exchange between multiples pairs of stations, without the intervention of the access point. For establishing concurrent transmission, the access point periodically broadcasts a signal message to the stations over a wireless communication channel to determine pairs of stations that are hidden from each other based on the interference power level reported by each station.

Abstract: A system and method for allocating a time slot to support data transmission between the co-located 802.11a/e and HIPERLAN/2 systems in a wireless local area network (WLAN) are provided. To comply with the H2 standard requirement of periodic transmission of the frame at every 2 msec, the access point (AP) performs the QoS CF-Poll function to allow the transmission of the H2 MAC frames to occur at n * 2 msec interval in the CCHC superframe, where the value of n depends on the HIPERLAN/2 MAC frame schedule of the AP. In particular, the AP polls itself to make other stations silent using the QoS CF-Poll function, then allocates a predetermined time period at each station to initiate H2 frame exchanges.

Abstract: In this document, we proposed a hybrid MAC protocol that can utilize the precious wireless link bandwidth efficiently in the environment of a partially connected wireless network topology and VBR connections running in the network.

Abstract: A medium access control (MAC) protocol is provided for avoiding collisions from stations (STAs) comprising two or more IEEE 802.11 basic service sets (BSSs) collocated and operating in the same channel during contention free periods (CFPs). The MAC protocol includes hardware/software for utilizing ready-to-send(RTS)/clear-to-send(CTS) exchange during CFPs to avoid potential collision from STAs in overlapping BSSs and hardware/software for providing overlapping network allocation vectors (ONAV) in addition to a network allocation vector (NAV), the ONAV included to facilitate the effectiveness of the RTS/CTS during CFPs.

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 between the AP and STAs within a particular basic service set (BSS) is needed; requesting a channel signal quality measure to some of the plurality of stations by the AP; reporting a channel signal quality report back to the AP based on a received signal strength indication (RSSI) and a packet error rate (PER) of all channels detected by the stations within the BSS; selecting a new channel based on the channel quality report for use in communication between the AP and the plurality of stations.