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Ashwin Sampath, Princeton US

Ashwin Sampath, Princeton, NJ US

Patent application numberDescriptionPublished
20090122782SYNCHRONIZATION OF WIRELESS NODES - A first wireless node may synchronize its timeslots with the timeslots of a second wireless node that was previously transmitting and receiving data in an asynchronous manner with respect to the timeslots of the first wireless node. By synchronizing timeslots, the wireless nodes may avoid interference that may otherwise occur if the wireless nodes operate in an asynchronous manner. A wireless node shares its timing information with other wireless nodes by repeatedly transmitting timing reference signals in conjunction with a synchronization metric that defines the relative priority of the timing reference. In the event a wireless node does not receive a GPS-based timing reference, the wireless node may synchronize to a timing reference based on the parameters of the synchronization metric of that timing reference. In the event a wireless node does not receive any timing references, the wireless node may define and advertise it's a timing reference and associated synchronization metric. To avoid synchronization race conditions, the synchronization metrics may be defined such that wireless nodes that have different timing references will advertise different synchronization metrics.05-14-2009
20090131061BEACON-BASED CONTROL CHANNELS - Systems and methodologies are described that facilitate transmitting control information in wireless networks. Portions of bandwidth can be blanked for transmitting control information, and the control information transmitters can utilize beacon symbols to convey the control information. In this regard, interference is mitigated with respect to data transmissions over the control information bandwidth. Selected frequencies of the beacon symbols in a codeword can be used to indicate the control information. The codewords can be encoded with an error control code to provide redundancy for decoding in the presence of some interference.05-21-2009
20090161636FLEXIBLE CONTROL CHANNELS FOR UNPLANNED WIRELESS NETWORKS - A wireless node configured to communicate with a remote node using a timeslot structure. The timeslot structure includes a plurality of data channels and a plurality of control channels, wherein each of the control channels comprises a plurality of control units. The wireless node is further configured to assign any one of a plurality of control messages for the data channels to any one of the control units.06-25-2009
20090175324DYNAMIC INTERFERENCE CONTROL IN A WIRELESS COMMUNICATION NETWORK - A method and apparatus for dynamic interference management is disclosed. A frequency channel is partitioned into a plurality of groups. Two or more groups are assigned weights reflecting degrees of disadvantage of a node. Each group is further partitioned into a plurality of tones. A node experiencing interference determines a group, selects a tone within the group, and transmits a wireless signal using the selected tone. A receiving node receives a plurality of tones including the selected tone, identifies active tones from the received tones, and determines a response based on the weights of the active tones.07-09-2009
20090191817Adaptive transmission of resource utilization messages based on throughput - 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.07-30-2009
20090191890ADAPTIVE TRANSMISSION OF RESOURCE UTILIZATION MESSAGES - 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.07-30-2009
20090196221METHOD AND APPARATUS FOR PROVIDING SIGNALING ACCESS - Signaling-only access may be established with an access node under certain circumstances such as, for example, upon determining that a node is not authorized for data access at the access node. A node that is not authorized for data access at an access node may still be paged by the access node through the use of signaling-only access. In this way, transmissions by the access node may not interfere with the reception of pages at the node. A first node may be selected for providing paging while a second node is selected for access under certain circumstances such as, for example, upon determining that the second node provides more desirable service than the first node.08-06-2009
20090197570PAGING AND ACCESS VIA DIFFERENT NODES - Signaling-only access may be established with an access node under certain circumstances such as, for example, upon determining that a node is not authorized for data access at the access node. A node that is not authorized for data access at an access node may still be paged by the access node through the use of signaling-only access. In this way, transmissions by the access node may not interfere with the reception of pages at the node. A first node may be selected for providing paging while a second node is selected for access under certain circumstances such as, for example, upon determining that the second node provides more desirable service than the first node.08-06-2009
20090201846SYSTEM AND METHOD FOR SCHEDULING OVER MULTIPLE HOPS - Systems and methodologies are described that facilitate scheduling over multiple hops in a wireless communication network. Radio resources can be partitioned into sets of sub-frames that can be allocated statically and/or dynamically. Statically allocated radio resources can be reassigned over time based on the loading on each hop and/or throughput imbalance. In addition, dynamic assignment of sub-frames to each hop can be based on traffic or channel conditions. Moreover, the radio resources can be dynamically allocated in a distributed scheme, wherein a base station controls the scheduling of resources, or a centralized scheme, wherein a relay station controls the scheduling of resources. Furthermore the allocation of radio resources can be transparent or explicit. In the transparent case, the access terminal listens directly to the base station, and the relay station does not transmit control information, such as DL or UL assignments. Conversely, when the allocation of resources is explicit the relay station does transmit control information.08-13-2009
20090203320ASYNCHRONOUS INTERFERENCE MANAGEMENT BASED ON TIMESLOT OVERLAP - Interference management may involve the transmission of interference management messages by wireless nodes that are experiencing interference and appropriate responses by potential interferers that receive the interference management messages. Upon detection of interfering signals, a wireless node may determine whether the signals are from a synchronous interferer or an asynchronous interferer. Based on this determination, the wireless node may use different types of signals to manage the different types of interference. In some aspects, asynchronous interference management may involve backing-off in frequency and/or in time in response to interference signals. Asynchronous interference management may involve transmitting back-off beacons to clear potential interferers from a given carrier. Here, the transmission of beacons by a wireless node may be metered to facilitate fair sharing of communication resources.08-13-2009
20090203322ASYNCHRONOUS INTERFERENCE MANAGEMENT - Interference management may involve the transmission of interference management messages by wireless nodes that are experiencing interference and appropriate responses by potential interferers that receive the interference management messages. Upon detection of interfering signals, a wireless node may determine whether the signals are from a synchronous interferer or an asynchronous interferer. Based on this determination, the wireless node may use different types of signals to manage the different types of interference. In some aspects, asynchronous interference management may involve backing-off in frequency and/or in time in response to interference signals. Asynchronous interference management may involve transmitting back-off beacons to clear potential interferers from a given carrier. Here, the transmission of beacons by a wireless node may be metered to facilitate fair sharing of communication resources.08-13-2009
20090203372SYNCHRONOUS AND ASYNCHRONOUS INTERFERENCE MANAGEMENT - Interference management may involve the transmission of interference management messages by wireless nodes that are experiencing interference and appropriate responses by potential interferers that receive the interference management messages. Upon detection of interfering signals, a wireless node may determine whether the signals are from a synchronous interferer or an asynchronous interferer. Based on this determination, the wireless node may use different types of signals to manage the different types of interference. In some aspects, asynchronous interference management may involve backing-off in frequency and/or in time in response to interference signals. Asynchronous interference management may involve transmitting back-off beacons to clear potential interferers from a given carrier. Here, the transmission of beacons by a wireless node may be metered to facilitate fair sharing of communication resources.08-13-2009
20090207730SCHEDULING POLICY-BASED TRAFFIC MANAGEMENT - Various traffic management techniques may be employed in a multi-hop wireless communication system. For example, a decision to transmit data to another node may be based on whether that node is able to effectively transmit its data. A decision to transmit an interference management message may be based on the amount of data a parent node may transmit. A decision to transmit an interference management message may be based on how effectively data is being transmitted. A weight may be assigned for an interference management message based on a traffic scheduling policy.08-20-2009
20090207777TRAFFIC MANAGEMENT FOR MULTI-HOP WIRELESS COMMUNICATION - Various traffic management techniques may be employed in a multi-hop wireless communication system. For example, a decision to transmit data to another node may be based on whether that node is able to effectively transmit its data. A decision to transmit an interference management message may be based on the amount of data a parent node may transmit. A decision to transmit an interference management message may be based on how effectively data is being transmitted. A weight may be assigned for an interference management message based on a traffic scheduling policy.08-20-2009
20090209262TRAFFIC MANAGEMENT EMPLOYING INTERFERENCE MANAGEMENT MESSAGES - Various traffic management techniques may be employed in a multi-hop wireless communication system. For example, a decision to transmit data to another node may be based on whether that node is able to effectively transmit its data. A decision to transmit an interference management message may be based on the amount of data a parent node may transmit. A decision to transmit an interference management message may be based on how effectively data is being transmitted. A weight may be assigned for an interference management message based on a traffic scheduling policy.08-20-2009
20090219851ADDING HYBRID ARQ TO WLAN PROTOCOLS WITH MAC BASED FEEDBACK - A wireless node having a MAC layer configured to coordinate access to a shared wireless medium using a MAC protocol, a PHY layer configured to provide an interface to the shared wireless medium, and a HARQ layer between the MAC and PHY layers, the HARQ layer being configured to support HARQ using the MAC protocol.09-03-2009
20090238289CHANNEL ESTIMATION IN WIRELESS SYSTEMS WITH IMPULSIVE INTERFERENCE - Systems and methodologies are described that facilitate detecting impulsive interference of pilot signals in wireless communications networks and accounting for such interference in estimating data channels to decode the pilot signals. Portions of a received pilot signal can be compared to other portions to create correlated subsets of similar portions. The number of portions in a subset can indicate a high likelihood of non-interference, and portions that are not in the subsets can be disregarded or weighted less in estimating channels for decoding. In cases of ambiguous subsets or portions, one or more subsets/portions can each be used to estimate the channel and data can be decoded multiple times. The decoding that results in a higher decoding metric can be selected. Additionally, systems and methodologies for inserting pilot signals within data are described.09-24-2009
20090245182ADAPTIVELY REACTING TO RESOURCE UTILIZATION MESSAGES INCLUDING CHANNEL GAIN INDICATION - An adaptable decision parameter is used to determine whether to react to resource utilization messages. The decision parameter may comprise a decision threshold that is adapted based on received resource utilization messages. The decision parameter may comprise a probability that is used to determine whether to react to a received resource utilization message. Such a probability may be based on, for example, one or more channel conditions, the number of interferers seen by a node, the number of received resource utilization messages, or some other form of resource utilization message-related information.10-01-2009
20090247177ADAPTING DECISION PARAMETER FOR REACTING TO RESOURCE UTILIZATION MESSAGES - An adaptable decision parameter is used to determine whether to react to resource utilization messages. The decision parameter may comprise a decision threshold that is adapted based on received resource utilization messages. The decision parameter may comprise a probability that is used to determine whether to react to a received resource utilization message. Such a probability may be based on, for example, one or more channel conditions, the number of interferers seen by a node, the number of received resource utilization messages, or some other form of resource utilization message-related information.10-01-2009
20090279563SIGNALING SEPARATE UNICAST AND BROADCAST INFORMATION WITH A COMMON PILOT - Aspects describe conveying unicast information and broadcast information in a resource set for a transmission request. The unicast information and broadcast information can be transmitted at substantially the same time. Power control can be applied separately to the unicast information and the broadcast information for reliable decoding. A null request can be indicated by “00” bits in a unicast portion and a zero power level in the broadcast portion.11-12-2009
20090285119INFRASTRUCTURE ASSISTED DISCOVERY IN A WIRELESS PEER-TO-PEER NETWORK - Apparatuses and methods are disclosed for infrastructure assisted discovery in wireless peer-to-peer networks. Various discovery procedures may be implemented where a first node supports discovery of other nodes for a second node.11-19-2009
20090286481DYNAMIC INTERFERENCE MANAGEMENT FOR WIRELESS NETWORKS - Methods and apparatuses for dynamic interference management for wireless networks are disclosed. A node in a wireless network is configured to determine whether to cease transmissions during a period of time designated for a first node to transmit to a second node based on at least parameter relating to a channel between the first and second nodes.11-19-2009
20090287827MANAGING DISCOVERY IN A WIRELESS PEER-TO-PEER NETWORK - Apparatuses and methods are disclosed for managing discovery in wireless peer-to-peer networks. Various discovery procedures may be implemented by supporting a broadcast of a plurality of discovery signals spaced apart in time by silent periods from a peer node and changing the duration of at least one of the silent periods.11-19-2009
20090323598METHOD AND APPARATUS FOR RESOURCE UTILIZATION MANAGEMENT IN A MULTI-CARRIER COMMUNICATIONS SYSTEM - Systems and methods are described that facilitate evaluating conditions of nodes (e.g., access points, access terminals, etc.) in a wireless communication environment having a plurality of carriers to determine a level of disadvantage for a given node relative to other nodes. The node may transmit a resource utilization message (RUM) that represents the level of disadvantage for the node and request other interference nodes to back off on one or more carriers.12-31-2009
20100027479TONE SELECTION IN COMMUNICATION NETWORKS - Tones within a channel can be selected randomly and/or based on orthogonal tone selection. Random selection can include selecting tones randomly from a fixed set, which is referred to as channelized tone selection. Channelized tone selection can be chosen if a critical tone exists. Random selection can also include selecting resources randomly from the total number of resources available, which is referred to as non-channelized tone selection. Orthogonal tone selection can be chosen to mitigate the probability of receiver desensitization and/or to attempt to mitigate interference.02-04-2010
20100118793COMMUNICATIONS METHODS AND APPARATUS RELATED TO PATITIONED TRAFFIC SEGMENTS - Methods and apparatus related to partitioning traffic segments are described. An access router, having concurrent connections with two access terminals and desiring to transmit traffic signals to the two access terminals in the same traffic segment, partitions a traffic segment. The partition is such that a first portion of the traffic segment is allocated to a first access terminal and a second portion of the traffic segment is allocated to the second access terminal. Control information, e.g., identifying partition portion assignments, data rate and/or coding information, is also communicated in the traffic segment as in-band control signaling. An access terminal, to which some of traffic signals are directed, receives and recovers the in-band control signaling, identifying its allocated partition portion of the traffic segment and identifying data rate and/or coding information used. The access terminal receives the traffic segment signals in its allocated partition portion and recovers the traffic information.05-13-2010
20100118794PARTITIONED TRAFFIC SEGMENT COMMUNICATIONS METHODS AND APPARATUS - Methods and apparatus related to partitioning traffic segments are described. An access router, having concurrent connections with two access terminals, each desiring to transmit traffic signals to the access router in the same traffic segment, partitions a traffic segment. The partition is such that a first portion of the traffic segment is allocated to a first access terminal and a second portion of the traffic segment is allocated to the second access terminal. Control information, e.g., conveying partition information, is communicated to access terminals prior to the traffic segment. In some embodiments, the partition information is communicated as part of a transmission request response signal, e.g., via phase of the request response signal. An access terminal which has been allocated a traffic segment partition portion identifies is allocation from the transmitted control information, and subsequently transmits traffic signals to the access router in its allocated portion of the traffic segment.05-13-2010
20100120372METHODS AND APPARATUS FOR SUPPORTING DISTRIBUTED SCHEDULING USING QUALITY OF SERVICE INFORMATION IN A PEER TO PEER NETWORK - Methods and apparatus well suited to decentralized traffic scheduling in wireless peer to peer network are described. An individual wireless terminal corresponding to a peer to peer connection makes a transmitter yielding or receiver yielding decision for a traffic slot. Quality of service information is disseminated as part of the scheduling control signaling. A scheduling control signal, e.g., a traffic transmission request signal or a traffic transmission request response signal, includes a pilot portion and a quality of service information portion. The pilot facilitates the recovery of the quality of service information by a plurality of different devices which may have different channel conditions with respect to the transmitter of the scheduling control signal. The different devices may benefit from utilizing the recovered quality of service information in making a yielding decision regarding traffic signaling in a traffic segment.05-13-2010
20100142365BEACON CODING IN WIRELESS COMMUNICATIONS SYSTEMS - Systems and methodologies are described that facilitate transmitting beacon symbols of a beacon message such that a sequence of symbols can satisfy a linear constraint over a field where the field elements can be identified with carriers. In this regard, a coding scheme can be applied to a beacon message; the coding scheme can produce a plurality of beacon symbols to transmit on given subcarriers. A receiving device of the beacon symbols can decode a beacon message by receiving less than the total number of symbols in a beacon message and determining the remaining symbol subcarriers based on the linear constraint. Thus, more efficient decoding of beacons is facilitated as well as resolving beacon ambiguity by figuring out which symbols satisfy linear constraints for the symbols, and resolving time and frequency shift by detecting an offset that would result in satisfaction of the linear constraint.06-10-2010
20100195585METHODS AND SYSTEMS FOR SCHEDULING AMONG NODES FOR A DATA SLOT IN WIRELESS COMMUNICATION NETWORKS - A method of scheduling among a plurality of nodes may include performing a first sequence of steps followed by a second sequence of steps, each sequence including a Tx step followed by a Rx step. During the Tx step, a node may send a REQ signal containing a request to transmit. During the Rx step, another node may receive the request signal, and respond by sending a confirmation signal indicating an acceptation or a declination of the REQ signal. The REQ signal includes a unicast portion and a broadcast portion. In an uplink mode of the slot, the responding nodes may use the unicast portion of the REQ signal to send supplemental information, in addition to the indication of the acceptation or the declination of the REQ signal.08-05-2010
20100195626METHODS AND SYSTEMS FOR USER SELECTION IN WIRELESS COMMUNICATION NETWORKS - A method of scheduling data transmission in a wireless network is disclosed. The wireless network includes an access router and a plurality of access terminals connectable to the base station. The method includes determining a number of the access terminals that are connected to the base station, and comparing the number with a threshold. The method further includes determining, based on the comparison between the number of connected access terminals and the threshold, whether to send a dedicated control signal or a shared control signal from the base station, in order indicate which ones of the plurality of access terminals are scheduled to transmit data during a slot.08-05-2010
20100198953METHODS AND SYSTEMS FOR MANAGING CONTENTION AMONG NODES IN WIRELESS COMMUNICATION SYSTEMS - A method of managing contention in a wireless network is described. The wireless network may include an access router and a plurality of access terminals connectable to the base station. The method may include designating a data slot as a downlink slot or an uplink slot, and sending a signal from the access router to the access terminals to indicate the designation of the data slot. The access router may determine whether the data slot should be designated as a downlink slot or an uplink slot by assessing information such QoS (quality of service) requirements contained in a REQ message received from one or more of the access terminals, and information regarding buffer level received from one or more of the access terminals.08-05-2010
20100226317METHOD AND APPARATUS FOR TIMESLOT SWAPPING - All or a portion of a timeslot of a slotted communication system may be dynamically designated for transmitting or for receiving. For example, a timeslot originally designated for receiving information at a wireless node may be temporarily designated for transmitting information from the wireless node. Such a designation may be made to accommodate a temporary asymmetry in traffic flow between wireless nodes or may be made based on other criteria. In some aspects, a resource utilization messaging scheme may be employed to mitigate interference associated with the designation of timeslots for transmitting or receiving.09-09-2010
20100279707TIME OF ARRIVAL (TOA) ESTIMATION FOR POSITIONING IN A WIRELESS COMMUNICATION NETWORK - Techniques for determining time of arrivals (TOAs) of signals in a wireless communication network are described. Each cell may transmit (i) synchronization signals on a set of contiguous subcarriers in the center portion of the system bandwidth and (ii) reference signals on different sets of non-contiguous subcarriers distributed across the system bandwidth. A UE may determine TOA for a cell based on multiple signals transmitted on different sets of subcarriers. The UE may perform correlation for a first signal (e.g., a synchronization signal) from the cell to obtain first correlation results for different time offsets. The UE may perform correlation for a second signal (e.g., a reference signal) from the cell to obtain second correlation results for different time offsets. The UE may combine the first and second correlation results and may determine the TOA for the cell based on the combined correlation results.11-04-2010