Abstract: Numerous Clos Star Networks (CSNs), each constructed as a set of connectors providing single-hop paths for each pair of access nodes of a respective access group, are fused to form a large-scale global network providing at least one single-hop path for each pair of access nodes of the formed global network. The access groups are arranged into access bands of multiple access groups each. Connectors of CSNs are paired to form distributors so that each access node has multiple parallel single-hop paths to each other access node of the same access band and one single-hop path to each access node of each other access band. The distributors are clustered into a set of geographically-spread constellations and each access node of the global network has a direct multichannel link to each of a respective subset of constellations thus entirely eliminating use of cross connectors and significantly simplifying the network structure.

Abstract: Access nodes of a large-scale network are arranged into a number of groups. The groups are arranged into a number of bands. Each distributor of a pool of distributors interconnects each access node of a selected group to at least one channel from each group of a selected band. A discipline of allocating the selected group and the selected band to a distributor ensures that each access node has: a number, approximately equal to half the number of groups, of parallel single-hop paths to each other access node of a same group; a number, approximately equal to half the number of bands, of parallel single-hop paths to each access node of a different group within a same band; and one single-hop path to each other access node of a different access band. To eliminate the need for cross connectors, geographically-spread distributors are arranged into geographically-spread constellations of collocated distributors.

Abstract: A passive signal transport medium, constructed as an array of spectral-temporal connectors, connects a large number of access nodes to a number of distributors to form a single-hop network of wide coverage and high throughput yet simplified control. Parameterized spectral-temporal connectors define network expansion over networks using conventional signal transport media. A network accommodating 32000 access nodes with a throughput of an Exabits/second is realizable. The distributors may be geographically distributed (the access nodes are naturally geographically distributed). The entire network structure is parameterized. Selecting the number of distributors to equal the number of access nodes, and pairing each access node with a respective distributor to form an integrated node, an expanded fully-meshed network is realized with each pair of integrated nodes having a direct path and numerous single-hop paths.

Abstract: A method of time aligning signals transmitted from a plurality of access nodes to a distributor is disclosed. The signals are formed according to a cyclic structure of a predetermined number of segments, including content segments and control segments, each segment having two markers. A controller of the distributor allocates observation time slots for each access node corresponding to control segments. The controller detects, from a portion of a signal received from an access node during a respective observation time slot, a position of a particular marker and a segment index then determines a temporal displacement of the signal accordingly. If the temporal displacement exceeds a predefined value, a distributing mechanism of the distributor halts signal transfer from the access node to all other access nodes and instructs the access node to adjust transmission time according to the temporal displacement.

Abstract: A detect-and-avoid system for an ownship aircraft is disclosed. The system has a control station in communication with an ownship aircraft, and a Passive Secondary Surveillance Radar (PSSR) system at the ownship aircraft. The PSSR is equipped to receive a reply from a target object, in response to an interrogation signal of staggered P1 and P3 pulses sent by a narrow-beam antenna of a Secondary Surveillance Radar (SSR) to the target object, and also to receive P2 pulses transmitted by a wide-beam antenna of the SSR. A pulse repetition frequency (PRF) pattern for the staggered interrogation signal is determined, followed by estimating a transmit time of the interrogation signal, and determining a position of the target object. A corresponding detect-and-avoid method is also disclosed.

Abstract: Access nodes of a large-scale network are arranged into a number of groups. The groups are arranged into a number of bands. Each distributor of a pool of distributors interconnects each access node of a selected group to at least one channel from each group of a selected band. A discipline of allocating the selected group and the selected band to a distributor ensures that each access node has: a number, approximately equal to half the number of groups, of parallel single-hop paths to each other access node of a same group; a number, approximately equal to half the number of bands, of parallel single-hop paths to each access node of a different group within a same band; and one single-hop path to each other access node of a different access band. To eliminate the need for cross connectors, geographically-spread distributors are arranged into geographically-spread constellations of collocated distributors.

Abstract: Constellations of distributors interconnect access nodes to form a vast contiguous network. The access nodes are generally geographically spread and the constellations are generally geographically spread, however the distributors within each constellation are collocated. The access nodes are arranged into access groups. The access nodes of each access group interconnect through selected constellations, with each access node having a wavelength-division-multiplexed (WDM) link to each of the selected constellations, to form a three-stage network. The three-stage networks corresponding to the access groups are mutually fused so that an access node of any three-stage network has multiple paths, each traversing one distributor, to each other access node of the same three-stage network and a path to each other access node of the entire network traversing one distributor. The distributors are preferable configured as fast optical switches.

Abstract: A method of time aligning signals transmitted from a plurality of access nodes to a distributor is disclosed. The signals are formed according to a cyclic structure of a predetermined number of segments, including content segments and control segments, each segment having two markers. A controller of the distributor allocates observation time slots for each access node corresponding to control segments. The controller detects, from a portion of a signal received from an access node during a respective observation time slot, a position of a particular marker and a segment index then determines a temporal displacement of the signal accordingly. If the temporal displacement exceeds a predefined value, a distributing mechanism of the distributor halts signal transfer from the access node to all other access nodes and instructs the access node to adjust transmission time according to the temporal displacement.

Abstract: Sensor nodes each equipped with a directional antenna configured to form a set of beams of predefined directions, with respect to a global reference direction, during beam cycles timed according to a global time reference form a sensor network. An electronic compass determines the global reference direction and a Global-Positioning-System (GPS) receiver provides the global time reference. The directional antenna is implemented as a phased-array antenna. During each beam period within a beam cycle, a phased-array controller determines a phase vector as a function of the geometrical arrangement of antenna elements and angular displacement of a reference direction of a node from the global reference direction. The phase vector is supplied to phase shifters coupled to the antenna elements to form a beam of a specified direction. During each beam period, all sensor nodes form beams of a same direction thus guaranteeing inter-nodal communication among neighboring nodes.

Abstract: An apparatus for fast clustering of massive data is disclosed. A set of variates characterizes a population of objects with the domain of each variate segmented into a variate-specific number of population strata. The set of variates and the variate-specific population strata define boundaries of a number of cluster zones. Each object of the population of objects is allocated to a cluster corresponding to a respective cluster zone according to the boundaries of the cluster zones and object vectors individually characterizing the population of objects. Upon receiving a specific object vector of a model object, a specific cluster compatible with the model object is determined according to the specific object vector and the boundaries of the cluster zones.

Abstract: Methods and apparatus for directing access to sources of information through an information dissemination network are disclosed. Upon detecting a user's access to a source, a recommendation to access a complementing source is communicated to the user. The recommendation is based on affinity measures for pairs of sources of information. Upon detecting the user's access transition to a new source of information within a predefined time interval, inter-source transition scores are recorded and new affinity levels of the current source to the new source are determined for each affinity measure. Affinity merits corresponding to affinity levels are determined based on tracking a population of users and determining users' compliance with recommendation. A complementing source is selected according to affinity merits corresponding to specific affinity levels of a current source to a set of sources.

Abstract: A method and apparatus for enhancing aviation safety, ensuring that unmanned aircraft remain well clear of other flying objects, are disclosed. A control station acquires a direction of a path of a flying object and periodically transmits requests to a transponder of the flying object to acquire specific data. Upon receiving a response to a request, a range of the flying object from the control station is determined. Using data acquired from each three consecutive responses, the displacement magnitude, the speed, and angular displacements of the flying object are determined. The method assesses potential crossing of a protection zone surrounding a protected aircraft based on most recent acquired data.

Abstract: Constellations of distributors interconnect access nodes to form a vast contiguous network. The access nodes are generally geographically spread and the constellations are generally geographically spread, however the distributors within each constellation are collocated. The access nodes are arranged into access groups. The access nodes of each access group interconnect through selected constellations, with each access node having a wavelength-division-multiplexed (WDM) link to each of the selected constellations, to form a three-stage network. The three-stage networks corresponding to the access groups are mutually fused so that an access node of any three-stage network has multiple paths, each traversing one distributor, to each other access node of the same three-stage network and a path to each other access node of the entire network traversing one distributor. The distributors are preferable configured as fast optical switches.

Abstract: A vast contiguous network comprises a large number of three-stage networks, each constituent three-stage network interconnecting a group of access nodes to a group of distributors. The three-stage networks are mutually fused where each pair of three-stage networks shares a respective distributor so that each distributor of the entire network is common in exactly two three-stage networks. Consequently, each access node has multiple parallel paths, each traversing one distributor, to each access node of a same access group and a path traversing one distributor, in addition to numerous compound paths, to each access node of a different access group. Each access node of the contiguous network has a cyclic time-limited dedicated dual control path to each distributor of a respective distributor group as well as a dedicated end-to-end control path, configured as a reserved time-limited path or a contention-free path, to each other access node of the contiguous network.

Abstract: A method and apparatus for optimal signal encoding based on reference data relating encoded-signal characteristics to encoding parameters are disclosed. Reference vectors of encoding parameters and corresponding measurements of encoded-signal characteristics are used to establish a functional relationship between each characteristic and the encoding parameters. Candidate vectors of encoding parameters are identified based on user-defined boundaries of both the encoding parameters and acceptable encoded-signal characteristics. A figure of merit is determined for each candidate vector and the candidate vector of highest figure of merit is presented to an encoder.

Abstract: A vast contiguous network comprises a large number of three-stage networks, each constituent three-stage network interconnecting a group of access nodes to a group of distributors. The three-stage networks are mutually fused where each pair of three-stage networks shares a respective distributor so that each distributor of the entire network is common in exactly two three-stage networks. Consequently, each access node has multiple parallel paths, each traversing one distributor, to each access node of a same access group and a path traversing one distributor, in addition to numerous compound paths, to each access node of a different access group. Each access node of the contiguous network has a cyclic time-limited dedicated dual control path to each distributor of a respective distributor group as well as a dedicated end-to-end control path, configured as a reserved time-limited path or a contention-free path, to each other access node of the contiguous network.

Abstract: A method and apparatus for optimal signal encoding based on reference data relating encoded-signal characteristics to encoding parameters are disclosed. Reference vectors of encoding parameters and corresponding measurements of encoded-signal characteristics are used to establish a functional relationship between each characteristic and the encoding parameters. Candidate vectors of encoding parameters are identified based on user-defined boundaries of both the encoding parameters and acceptable encoded-signal characteristics. A figure of merit is determined for each candidate vector and the candidate vector of highest figure of merit is presented to an encoder.

Abstract: A large-scale contiguous network comprises access nodes arranged into access groups and distributors arranged into constellations of collocated distributors. The distributors may comprise switches, rotators, or a mixture of switches and rotators. Each access group connects to each distributor of a respective set of distributors selected so that each pair of access groups connects once to a respective distributor. At least one access group comprises a global controller. Each access node has a dual multichannel link to each constellation of a respective set of constellations, the link carrying a set of dual channels connecting through a spectral demultiplexer and a spectral multiplexer to a subset of distributors. Each access node is equipped with a respective access controller having a memory device storing identifiers of dual paths to all other access nodes and the global controller, each path traversing only one distributor.

Abstract: A large-scale contiguous network comprises access nodes arranged into access groups and distributors arranged into constellations of collocated distributors. The distributors may comprise switches, rotators, or a mixture of switches and rotators. Each access group connects to each distributor of a respective set of distributors selected so that each pair of access groups connects once to a respective distributor. At least one access group comprises a global controller. Each access node has a dual multichannel link to each constellation of a respective set of constellations, the link carrying a set of dual channels connecting through a spectral demultiplexer and a spectral multiplexer to a subset of distributors. Each access node is equipped with a respective access controller having a memory device storing identifiers of dual paths to all other access nodes and the global controller, each path traversing only one distributor.

Abstract: Sensor nodes each equipped with a directional antenna configured to form a set of beams of predefined directions, with respect to a global reference direction, during beam cycles timed according to a global time reference form a sensor network. An electronic compass determines the global reference direction and a Global-Positioning-System (GPS) receiver provides the global time reference. The directional antenna is implemented as a phased-array antenna. During each beam period within a beam cycle, a phased-array controller determines a phase vector as a function of the geometrical arrangement of antenna elements and angular displacement of a reference direction of a node from the global reference direction. The phase vector is supplied to phase shifters coupled to the antenna elements to form a beam of a specified direction. During each beam period, all sensor nodes form beams of a same direction thus guaranteeing inter-nodal communication among neighboring nodes.