Abstract: A remote station communicates with a base station over a secondary radio channel. During communication, the remote station determines channel conditions of the secondary radio channel. Based on the channel conditions, the remote station selects one or more sensing methods to be performed on the secondary radio channel. The result of performing the sensing method is used to determining whether an incumbent signal is present on the secondary radio channel.

Abstract: A method, wireless device, and information processing system dynamically update spectrum sensing groups in a wireless communication system. A set of wireless devices (114) currently allocated to a spectrum sensing group is identified. Each wireless device (114, 116, 118) in the set performs spectrum sensing on one or more wireless communication channels. Spectrum sensing performance data (144) is analyzed for each such wireless device (114) in the set. The spectrum sensing performance data (144) indicates wireless communication performance of a wireless device (114) associated with the spectrum sensing performance data with respect to detecting a transmitted signal on the one or more communication channels. Wireless device membership of the set of wireless devices (114, 116, 118) allocated to the spectrum sensing group is dynamically adjusted based on the analysis.

Abstract: A cognitive radio wireless device (114) dynamically manages signal detection in a cognitive radio system (100). Spectrum sensing is performed for a first sensing frame on at least one communication channel. At least one observed signal is received (204) on the at least one communication channel. A detection decision (210) is performed to determine if the observed signal is noise or an active signal associated with an active user. The detection decision (210) is performed by comparing observed signal energy estimation with a current detection threshold. The current detection threshold can be an arbitrarily defined threshold or a detection threshold based on a previous detection decision for a sensing frame immediately prior to the first sensing frame.

Abstract: A method, wireless controller, and information processing system are provided to dynamically allocate spectrum sensing resources. A first input (804) including available sensing session time for performing spectrum sensing with respect to one or more primary systems (102) is received. A second input (806) including a set of communication channels to be monitored in the spectrum sensing session is received. A third input (808) including detection constraints associated with a plurality of available sensing nodes (114) in a secondary network (104) for performing the spectrum sensing is received. Spectrum sensing resources are dynamically allocated (814) among a set of the plurality of available sensing nodes (114) based on the first (804), second (806), and third inputs (808).

Abstract: A wireless communication system and method for determination of the location of a location-incapable device of a decentralized wireless communication network. Upon receipt of location determination information, relevant to the location of the location-incapable device in the network and sufficient to perform a calculation of the location of the location-incapable device, a location-capable device of the network may calculate the location of the location-incapable device and make this information available to one or more devices of the network.

Abstract: A location technique is utilized where channel-model parameters are originally estimated prior to location taking place. Location then takes place using a first set of known-located nodes, and the channel-model parameters are updated based on the distances resulting from the location estimate. Once the channel-model parameters have been updated, location again takes place using a second set of known-located nodes, node distances are calculated based on the produced locations and the channel-model parameters are again updated. This process continues until no significant change is observed between the previous and the newly estimated location, or until a maximum number of iterations is reached.

Abstract: A method and apparatus for determining the path loss model of an object within a wireless communication system is provided herein. During operation, a path loss model for a node is generated based on path loss values and corresponding numbers of neighbors of the said node. The path loss model is used to determine a relationship between path loss and distance. With this relationship established, distances to known-located nodes may be obtained by obtaining a path loss to the known-located node. From these distances, a node can then be located.

Abstract: A communications network (100) has coordinator devices (10) each transmitting a beacon message in a cluster area (30). Neighboring coordinator devices (1, 2) define overlap areas (60) in which each beacon message of the neighboring coordinator devices is present. Neighboring coordinator devices (1, 2) may also define non-overlap areas (204) in which each beacon message is present. A method for distributing communication signals includes providing nodes (50), (51,52) within a transmission region (30) of the coordinator devices (1, 2). The node (50) or nodes (51, 52) detect at least one beacon message of the neighboring coordinator devices (1, 2), determine the existence of a condition (302), and warn neighboring coordinator devices of the condition. The condition (302) is corrected by making an adjustment to the communication signal (such as beacon timing) by a correction amount (304).

Abstract: To enable wireless applications which require the use of location information, a method and apparatus for transmitting location data within an ad-hoc communication system is provided herein. During operation, a portion of a packet payload is used to transmit location coordinate information along with an identifier of location estimation technique utilized for a node, as well as other parameters that may be needed for location estimation. Nodes in the communication system calculate their location coordinates using the said portion of packets received from other nodes in the communication system.

Abstract: A method for peer-to-peer ranging and discovery of a rigid body existing in a scatternet having piconets and nodes includes the steps of defining a node (12) in a piconet (10) to be a piconet controller (PNC) having controller functions, locating a rigid body seed including the node (12), and discovering a rigid body by sequentially downloading controller functions of the piconet controller (12) to at least one border node. Also provided is a communications node including a receiver for receiving communications from other communications nodes in a communications range (R), a transmitter for sending communications to other communications nodes in the communications range (R), a memory storing at least ranging information and a unique identification for describing the node, and a processor connected to the receiver, to the transmitter, and to the memory, the processor being programmed to carry out the method according to the present invention.

Abstract: A method for estimating the location of a blindfolded node (235) in a wireless network having reference nodes (225, 230) is provided. The reference nodes (225, 230) are combined into pairs (301) and each pair is checked to determine if the reference nodes are within each other's communication rage (304). A plurality of probable regions (315) for the blindfolded node are obtained (313, 315). These probable regions are overlapped (320), and the blindfolded node's estimated location is estimated to be the geometric center of the overlapped regions (325).

Abstract: To reduce interference and increase battery life, a method and apparatus for transmitting location data within an ad-hoc communication system is provided herein. During operation, a portion of a beacon payload is reserved to broadcast location information (coordinates) for a node as well as other parameters that may be needed for location estimation. In addition to a node's location, an accuracy of the nodes location is also included within the beacon field. Because nodes will no longer have to awake outside their beacon transmit times to broadcast location information, battery life is extended. In addition, because nodes will no longer be transmitting location information outside their guaranteed time slot, system interference is also reduced.

Abstract: A location technique is utilized within a wireless communication system where power measurements from various nodes are weighted to determine a node's location. An iterative location process is executed where as more and more nodes are heard from, a node will re-locate itself in order to improve location accuracy.

Abstract: A wireless communication system and method for determination of the location of a location-incapable device of a decentralized wireless communication network. Upon receipt of location determination information, relevant to the location of the location-incapable device in the network and sufficient to perform a calculation of the location of the location-incapable device, a location-capable device of the network may calculate the location of the location-incapable device and make this information available to one or more devices of the network.

Abstract: A method for locating nodes in a multi-hop sensor network forms a rigid body (RB1, RB2, RB3) and, from the nodes, utilizes the rigid body to decide if a node is locatable. The method obtains a reduced order model (ROM) of the network by categorizing all of the nodes by location status, grouping them based upon the categorizations, and defining and identifying a rigid body from a group. The method further simplifies determinability of node location by forming the rigid body from the nodes based upon the categorized location status. To locate the nodes, the nodes are separated from one another into subsets dependent upon characteristics (100). Then, groups are formed from one subset (200) and the rigid body is formed from a group (300). The ROM is formed from the rigid body (400) and a location capability of the rigid body is evaluated based upon the ROM (500).

Abstract: A method and system is provided for determining a location for each of a plurality of units, which are sub-divided into more than one sub-net groupings, that each include two or more units. Within each sub-net grouping, measured range information between units within the sub-nets and one or more reference units is gathered in at least a selected one of the units. The selected one of the units then estimates a location for each of the units, which minimizes any error in the measured ranges between the units in each of the corresponding sub-nets.

Abstract: A method for reducing communications in a peer-to-peer wireless network having nodes includes sending an RTS-TOA ranging communication from a first node (N0) in a node group to another node (Nr, I) in the group, receiving the RTS-TOA communication with the second node (Nr, I) and sending a multi-cast CTS-TOA/RTS-TOA ranging communication from the second node (Nr, I) as a reply to the received RTS-TOA communication, and successively and sequentially repeating the multi-cast sending step for each of the nodes. A CTS-TOA message is a reply to the received RTS-TOA message and, simultaneously, is an RTS-TOA ranging communication to a new destination node (J). The method applies for a randomized communications approach when node identifications are not sequenced and to a sequential approach where nodes are sequenced, and also applies to completely connected and multi-hop networks. Also provided is a node for carrying out the method of the present invention.

Abstract: A method and location determination module is provided for determining a location of one of a plurality of units using neighbor lists. Each unit is communicatively coupled to at least some of the other plurality of units, where at least some of the plurality of units are reference units, whose locations are known. The units communicate with other nearby units within communication range, to establish neighbor lists. A unit to be located then identifies an aggregate value corresponding to the number of occurrences of the reference units in the neighbor list of the unit to be located and the neighbor lists of each of a group of associated units. The location of the unit to be located is then determined, based upon the known locations of the reference units and the number of identified occurrences of the reference units in the corresponding neighbor lists.

Abstract: A method and apparatus for determining the location of a node within a communication system is provided herein. During operation, located nodes (105) having known locations are utilized to locate “blind” nodes (200) whose location is to be determined. More particularly, a blind node (200) wishing to determine its location will measure a plurality of signal strengths between itself and a plurality of located nodes (105). Each located node's signal strength will then be adjusted based on at least one antenna gain pattern. A radio-location algorithm will then be executed on the adjusted signal-strength measurements to determine the nodes location.

Abstract: A method and apparatus for determining the location of a node within a communication system is provided herein. During operation, reference nodes (105) having known locations are utilized to locate “blind” nodes (104) whose location is to be determined. More particularly, a blind node (104) wishing to determine its location will measure a plurality of path losses between itself and a plurality of reference nodes (105). These reference nodes' locations will then be mathematically weighted by the path loss between these reference nodes (105) and the blind node (104). The location of the blind node (104) is a sum of the mathematically weighted reference nodes' locations.