Abstract: Providing fairness-based metrics for managing inter-sector interference of a mobile AN is described herein. By way of example, accumulation of resource utilization messages (RUMs) at a sector of the mobile AN can be based at least in part on a performance metric of that sector as compared with one or more neighboring sectors. In at least one aspect, performance metrics of multiple sectors of the mobile AN can be aggregated and a RUM accumulation rate of each sector is determined based on the aggregated metric. Accumulation rates can further be updated periodically as sector and/or aggregated metrics of the mobile AN change. Accordingly, accumulation and utilization of RUMs is based on inter-sector fairness to optimize overall wireless communication quality of service for the mobile AN.

Abstract: An adaptive scheme controls the transmission of interference management messages by wireless nodes. For example, the adaptive scheme may be used to determine whether and/or how to transmit resource utilization messages. Such a determination may be based on, for example, comparison of a quality of service threshold with a current quality of service level associated with received data. A quality of service threshold may be adapted based on the effect of previously transmitted resource utilization messages. A quality of service threshold for a given wireless node may be adapted based on the frequency at which the wireless node transmits resource utilization messages. A quality of service threshold for a given wireless node may be adapted based on information received from another wireless node. An adaptation scheme also may depend on the type of traffic received by a given wireless node. A quality of service threshold also may be adapted based on throughput information.

Abstract: To select a transmission mode to use for a data transmission via a MIMO channel from station A to station B, station A obtains channel information used for spatial processing and determines the age of this information. Station A selects one of multiple transmission modes based on the age of the channel information and possibly other information (e.g., the fading characteristic of the MIMO channel). To select rate(s) to use for the data transmission, station A obtains channel state information (CSI) indicative of the received signal quality for the MIMO channel, e.g., received SNRs or “initial” rates. Station A determines the age of the CSI and selects one or more “final” rates based on the CSI, the age of the CSI, the selected transmission mode, and possibly other information. Station A processes data in accordance with the selected transmission mode and final rate(s) and transmits the processed data to station B.

Abstract: Techniques for resolving blinded-node problems are described herein. One aspect operates on the physical (PHY) layer only, which a second layer operates on the medium access control (MAC) layer. Both aspects involve having a node stop processing a data packet that is not destined for it so as to be able to reserve its resources to detect control and other packets. An apparatus for implementing the techniques are also disclosed.

Abstract: Beacons may be grouped to facilitate neighbor discovery in a wireless network. For example, neighboring access devices such as IEEE 802.11 access points may cooperate to transmit beacons in a group. In this way, a wireless device seeking to discover the neighboring access devices may scan for the beacons for a shorter period of time. An indication may be provided to enable a wireless device to more efficiently scan the beacons. For example, the indication may indicate the channel the wireless device should scan to receive the next beacon that is to be transmitted. In addition, the indication may include information relating to the transmission time of the next beacon.

Abstract: Techniques for using at least one of omni-directional and directional antennas for communication are described. A station may be equipped antenna elements selectable for use as an omni-directional antenna or one or more directional antennas. The station may select the omni-directional antenna or a directional antenna for use for communication based on various factors such as, e.g., whether the location or direction of a target station for communication is known, whether control frames or data frames are being exchanged, etc.

Abstract: An apparatus includes a processing system configured to establish a link with any one of a plurality of access points in a mesh network, each of the access points providing the apparatus with a different data path through the mesh network. The processing system is further configured to compute a metric for each of the data paths and select one of the access points to establish the link with based on the metrics. In a centralized mesh network, an apparatus includes a processing system configured to compute, for each of the access points, a metric for each of a plurality of data paths supportable by that access point, and establish interconnections between the access points based on the metrics.

Abstract: Systems and methodologies are described that facilitate communication in a wireless network environment. In particular, access points can dynamically adjust transmit power and/or carrier-sensing thresholds to allow multiple access points to communicate concurrently. In aspects, access points exchange node information, including RSSI and node addresses, of nearby nodes. The node information can be utilized to detect hidden nodes and estimate interference levels. Transmit power and/or carrier-sensing thresholds can be modified as a function of distance between source and destination access points, interference from hidden nodes, transmission rates, and/or path loss.

Abstract: Techniques for controlling transmissions in wireless communication networks are described. In one aspect, transmission control for a mesh network may be achieved by ranking mesh points or stations in the mesh network. In one design, the rank of a first station in the mesh network may be determined. At least one station of lower rank than the first station in the mesh network may be identified. At least one transmission parameter for the at least one station of lower rank may be set by the first station. In another aspect, stations may be assigned different transmission parameter values to achieve the data requirements of each station. At least one transmission parameter value may be selected for each station based on the rank, QoS requirements, amount of traffic, and/or achievable data rate for that station and may be sent (e.g., via a probe response message) to the station.

Abstract: An apparatus and method of controlling a traffic stream in a mesh network comprising receiving at a second node a traffic stream admission request to admit a traffic stream from a first node, determining a traffic load for the second node, and determining whether to admit or deny the traffic stream from the first node using the traffic load.

Abstract: Flows admitted to a mesh node may be controlled through contention access parameters. The admitting node may determine a desired transmission opportunity duration, and a transmission opportunity frequency. Furthermore, the node may achieve the flow rate and delay bound requirements of the admitted flow based at least in part upon the desired transmission opportunity duration, and the transmission opportunity frequency. The data rate and the access frequency of the admitted node may be monitored at the physical access level. The flow rate requirement may be accomplished based at least in part upon an adjustment to the transmission opportunity duration. The delay bound requirement may be accomplished at least in part upon manipulation of the contention access parameters. The transmission opportunity duration and the access parameters may be determined by the upstream admitting nodes, which may reduce congestion near mesh portals, and accomplish increased data transfer.

Abstract: Traffic streams through mesh points in a mesh network are managed. Data arriving at the mesh point are aggregated in packet queues. The packet queues segregate arriving data by the data's Quality of Service (QoS) requirement. An appropriate communication channel is selected. The communication channel is accessed through a contention access schema. An M-Request-To-Send (MRTS) message is sent to potential receiving mesh points with receiving mesh points responding with an M-Clear-to-Send (MCTS) message. Data from the packet queues is transmitted to the next mesh point. A mesh point power save mode allows battery operated mesh points to sleep preserving power.

Abstract: Maintaining a cache of indications of exclusively-owned coherence state for memory space units (e.g., cache line) allows reduction, if not elimination, of delay from missing store operations. In addition, the indications are maintained without corresponding data of the memory space unit, thus allowing representation of a large memory space with a relatively small missing store operation accelerator. With the missing store operation accelerator, a store operation, which misses in low-latency memory (e.g., L1 or L2 cache), proceeds as if the targeted memory space unit resides in the low-latency memory, if indicated in the missing store operation accelerator. When a store operation misses in low-latency memory and hits in the accelerator, a positive acknowledgement is transmitted to the writing processing unit allowing the store operation to proceed. An entry is allocated for the store operation, the store data is written into the allocated entry, and the target of the store operation is requested from memory.

Abstract: Techniques for selecting rates for data transmission on eigenmodes of a MIMO channel are described. An access point transmits an unsteered MIMO pilot via the downlink. A user terminal estimates the downlink channel quality based on the downlink unsteered MIMO pilot and transmits an unsteered MIMO pilot and feedback information via the uplink. The feedback information is indicative of the downlink channel quality. The access point estimates the uplink channel quality and obtains a channel response matrix based on the uplink unsteered MIMO pilot, decomposes the channel response matrix to obtain eigenvectors and channel gains for the eigenmodes of the downlink, and selects rates for the eigenmodes based on the estimated uplink channel quality, the channel gains for the eigenmodes, and the feedback information. The access point processes data based on the selected rates and transmits steered data and a steered MIMO pilot on the eigenmodes with the eigenvectors.

Abstract: Intelligent prediction of critical sections is implemented using a method comprising updating a critical section estimator based on historical analysis of atomic/store instruction pairs during runtime and performing lock elision when the critical section estimator indicates that the atomic/store instruction pairs define a critical section.

Abstract: Techniques for scheduling flows and links for transmission are described. Each link is an oriented source-destination pair and carries one or more flows. Each flow may be associated with throughput, delay, feedback (e.g., acknowledgments (ACKs)) and/or other requirements. A serving interval is determined for each flow based on the requirements for the flow. A serving interval is determined for each link based on the serving intervals for all of the flows sent on the link. Each link is scheduled for transmission at least once in each serving interval, if system resources are available, to ensure that the requirements for all flows sent on the link are met. The links are also scheduled in a manner to facilitate closed loop rate control. The links are further scheduled such that ACKs for one or more layers in a protocol stack are sent at sufficiently fast rates.

Abstract: To select a transmission mode to use for a data transmission via a MIMO channel from station A to station B, station A obtains channel information used for spatial processing and determines the age of this information. Station A selects one of multiple transmission modes based on the age of the channel information and possibly other information (e.g., the fading characteristic of the MIMO channel). To select rate(s) to use for the data transmission, station A obtains channel state information (CSI) indicative of the received signal quality for the MIMO channel, e.g., received SNRs or “initial” rates. Station A determines the age of the CSI and selects one or more “final” rates based on the CSI, the age of the CSI, the selected transmission mode, and possibly other information. Station A processes data in accordance with the selected transmission mode and final rate(s) and transmits the processed data to station B.

Abstract: A method and structure for equipping a cache with information to enable the processor to track and report whether a given speculative access causes prefetches and/or pollutions of the cache. Two types of events are tracked in one of two different ways: first by counting/tracking prefetch operations, either globally or on a per instruction address basis and then by counting/tracking cache pollutions, either globally or on a per instruction address basis.

Abstract: A clustering based load adaptive sleeping protocol for ad hoc networks includes a plurality of nodes forming a cluster, where the nodes in the cluster are partitioned into n groups. This partitioning is performed based on the node ID (e.g. node_id modulo n). The cluster head transmits a beacon at fixed intervals. The beacon interval is divided into N slots, where N is a multiple of n. Node sleep/activation times are synchronized to the beacon interval slots. The node's group number is used to determine the slots within a beacon interval that a node begins it s sleep cycle. Therefore, no additional signaling is required between nodes to indicate sleep patterns. The sleeping time of each node may be increased when extended periods of inactivity are detected according to an adaptive procedure.

Abstract: An advance over the prior art is achieved through an efficient method for an admission control algorithm and a scheduling mechanism that complement each other in providing the following three classes of service. A first class of service is termed Class 1 where users specify a nominal amount of bandwidth desired. A second, lower tier service class is termed Class 2, wherein users specify a nominal and minimum amount of bandwidth desired when entering into a network connection. A third server class is Class 3, where Class 3 users are treated as best effort users. For Class 1 users the methodology of the present invention provides a guaranteed nominal amount of bandwidth. The admission control procedure ensures that Class 1 users are admitted only if resources exist to satisfy the nominal bandwidth requirements of the Class 1 users. Class 2 users are admitted if resources exist to satisfy the minimum bandwidth requirements of the user.