Abstract: This invention relates to switching power saving modes and rescheduling communication frames for various periods of a beacon interval (BI) defined under WGA Draft Specification 0.8 for the personal basic service set (PBSS) and infrastructure BSS to achieve further power savings and other advantages. Stations can be awake during a contention-based period (CBP) if it is in active state and can schedule frames during a service period (SP) to allow the assigned receiver to transmit to the assigned initiator. Stations in a group can schedule a group address frame to be sent during the CBP and group SP of a specific periodic BI. Stations in peer-to-peer connection may directly notify its peer stations of its power saving mode and wakeup schedule. Stations of an infrastructure basic service set (BSS) can also use the same power saving mechanism as stations of a PBSS noting a difference where each BI will be an access point's (AP's) awake BI.

Abstract: Handover of the role of a personal basic service set coordination point (PCP) in a personal wireless area network occurs with the issuance of a PCP handover request by the existing PCP station. A response from a PCP handover capable station within the BSS includes attributes of the responding station pertinent to its ability to carry out the role of a PCP. Once a new PCP station has been identified, handover steps are undertaken to modify beacon filtering and beam-forming in other non-PCP stations within the BSS to facilitate interruption free transition from the old PCP to the new PCP.

Abstract: Fair usage of working channels in a wireless network is disclosed. A base station associated with a cell within a wireless community monitors the congestion of the working channel of neighboring communities. Upon determining that the congestion of the working channel of a neighboring community is less than that of its existing working channel, the base station initiates a switch to the neighboring community's working channel. Upon joining the new community, the frame structure and other networking parameters and attributes are adjusted.

Abstract: A common control channel for base station (“BS”)/consumer premise equipment (“CPE”) communication in areas of overlapping coverage by wireless regional area network (“WRAN”) cells operating on different working channels is disclosed. A common control channel is selected from among the various working channels sensed in each of a plurality of overlapping WRAN cells so as to enable BS/CPE and BS/BS communication. Once chosen, each CPE within the overlapping area communicates with the controlling BS via an enhanced coexistence beacon protocol messages. These messages include timing and other synchronization information.

Abstract: A common control channel for base station (“BS”)/consumer premise equipment (“CPE”) communication in areas of overlapping coverage by wireless regional area network (“WRAN”) cells operating on different working channels is disclosed. A common control channel is selected from among the various working channels sensed in each of a plurality of overlapping WRAN cells so as to enable BS/CPE and BS/BS communication. Once chosen, each CPE within the overlapping area communicates with the controlling BS via an enhanced coexistence beacon protocol messages. These messages include timing and other synchronization information.

Abstract: Clean and reliable channel sensing during dynamic frequency hopping over a plurality of overlapping wireless regional area network (WRAN) cells is conducted using a minimum number of channels. By coordinating a phase-shift of the operation periods of each WRAN cell over a minimum number of working channels, interruption-free communication and data transmission for each of the WRAN cells as well as interference-free channel sensing can be achieved.

Abstract: Collisions between tunneled direct link setup (“TDLS”) requests are resolved by associating each request with a priority value. Upon issuing a TDLS request the encapsulated frame is associated with a priority value. When a station, which is waiting for a response from a recently issued TDLS request, receives a TDLS request from another station, a collision occurs. The collision is resolved by comparing the priority value associated with the TDLS request initiated by the station and the TDLS request received. The TDLS request with the higher priority value is pursued while the TDLS request with the lower priority value is ignored. The priority value can be based on the sending station's MAC address or other value which can differentiate the TDLS requests.

Abstract: In an embodiment, a channel estimator includes first and second stages. The first stage is operable to generate a respective one-dimensional array of first channel-estimation coefficients for each communication path of a communication channel, and the second stage is operable to generate a multi-dimensional array of second channel-estimation coefficients in response to the first channel-estimation coefficients. For example, such a channel estimator may estimate the response of a channel over which propagates an orthogonal-frequency-division-multiplexed (OFDM) signal that suffers from inter-carrier interference (ICI) due to Doppler spread. Such a channel estimator may estimate the channel response more efficiently, and with a simpler algorithm, than conventional channel estimators.

Abstract: This invention relates to cognitive radio based wireless communications of dynamic spectrum access networks, and more particularly to a method of addressing inter-systems (cells) coexistence and spectrum sharing. The described method of spectrum sharing called On-Demand Spectrum Contention, integrates Dynamic Frequency Selection and Transmission Power Control with iterative on-demand spectrum contentions and provides fairness, adaptability, and efficiency of spectrum access for dynamic spectrum access systems using active inter-system coordination.

Abstract: A Dynamic Frequency Hopping Community (DFH Community) is formed from a plurality of Wireless Regional Area Network (WRAN) cells wherein each of the plurality of WRAN cells within the DFH Community is a one-hop neighbor of the leader cell. The leader cell sets and distributes a hopping pattern for use among the WRAN cells based on, in part, the number of usable channels and whether a WRAN cell is shared by two groups in the DFH Community.

Abstract: This invention relates to cognitive radio based wireless communications of dynamic spectrum access networks, and more particularly to a method of addressing inter-systems (cells) coexistence and spectrum sharing. The described method of spectrum sharing, called On-Demand Spectrum Contention, integrates Dynamic Frequency Selection and Transmission Power Control with iterative on-demand spectrum contentions and provides fairness, adaptability, and efficiency of spectrum access for dynamic spectrum access systems using active inter-system coordination.

Abstract: A unified contention based protocol is implemented in which a source station within a basic service set selects the protection methodology for data transmission on the communication medium. Utilizing EDCA as a medium access method and maintaining that each transmission opportunity has multiple slots, the source station is provided with the opportunity to select a protection methodology based on the protection environment, which enables transmission opportunity protection without direct PCP involvement.

Abstract: SP recovery between communications of a source and destination apart from the PCP can occur by performing, prior to the initial frame response between a source and a destination, a back-off procedure using back-off parameters for SP recovery when the initiator of a SP cannot receive a responding frame from the destination and detects the communication medium being idle. In alternative embodiments the source and/or destination can send a notification frame to the PCP informing the PCP of transmission failure. When the PCP determines the communication medium to be idle, the PCP truncates and reallocates the remaining portion of the SP.

Abstract: In a PBSS cluster environment, the beacon interval is allocated such that each PBSS in a PBSS cluster possesses its own master sub-beacon interval. Moreover, each member of the PBSS cluster can share unoccupied sub-beacon intervals. When a master PBSS fails to use its own master sub-beacon interval or the beacon intervals which are unoccupied, the available idle time within the beacon interval can be utilized by other member PBSSs in the PBSS cluster. As available or idle beacon interval time is allocated, each master PBSS retains the highest priority to its own master sub-beacon interval thus providing immediate access to a beacon interval when necessary.

Abstract: A method for creating and maintaining semi-dynamic frequency hopping communities. Each community is a set of neighboring cells, such as wireless regional area networks (WRANs) according to IEEE 802.22, that follow a protocol defining coordinated frequency hopping operations, e.g., hopping is performed by community members according to a leader-defined hopping pattern rather than to channels selected in the prior operation period. Each community has one leader base station and one or more community member base stations. The leader determines membership, calculates hopping patterns for all members, and distributes the hopping information to the community members. Members provide their neighborhood and channel availability information, e.g., information about their sensing results and channel usage of neighboring WRANs.

Abstract: The addition of high throughput capability elements to beacon frames and peer link action frames in wireless mesh networks enable the utilization of desirable features without further modifications to the network. Rules can be established for high throughput mesh point protection in a mesh network, Space-time Block Code (STBC) operations and 20/40 MHz operation selections. However, features such as PSMP (power save multi-poll) and PCO (phased coexistence operations) are barred from implementation to prevent collisions.

Abstract: A reliable and deterministic video communication protocol is provided. In one aspect, a method of transmitting data, audio or video frames in a basic service set having a plurality of stations in a wireless local area network transmits a transmit opportunity information element to reserve a transmit opportunity time interval. The method further transmits the data, audio or video frames to a number of the stations in the basic service set during the reserved transmit opportunity time interval. In another aspect, a method of transmitting data, audio or video frames in a basic service set having a plurality of stations in a wireless local area network first transmits protection frames to reserve a time interval, then transmits frames during the reserved time interval or during a non-reserved time interval.

Abstract: Methods and apparatus for implementing a robust unicast/broadcast/multicast protocol are provided. In one aspect, a method of avoiding collision of intra-basic service set unicast, broadcast or multicast transmissions notifies stations in the basic service set of a reserved transmit opportunity for a unicast, broadcast or multicast transmission. Transmissions from at least one station in the basic service set are deferred until after the reserved unicast, broadcast or multicast transmit opportunity.

Abstract: Methods and apparatus for transmitting a video frame in wireless local area network communications are proposed. In one aspect, a method generates and transmits an IEEE 802.11 media access control (MAC) frame containing a video transport stream (VTS) frame. The VTS frame includes a video frame and a VTS control header that includes control information with respect to the video frame.

Abstract: In an embodiment, a multi-carrier signal (e.g., an OFDM signal) is received over a channel. Indicators of interference and the channel response at a carrier frequency of the signal are determined, and compared. If the indicator of interference has a particular relationship to the indicator of the channel response, then a data value transmitted at the carrier frequency is recovered from a data value received at the carrier frequency according to a particular data-recovery algorithm. Because the particular data-recovery algorithm may be faster than a conventional data-recovery algorithm, recovering one or more data values with the particular algorithm may increase the speed at which data is recovered from a multicarrier signal as compared to using a conventional data-recovery algorithm.