Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that minimizes the probability of interfering with existing legacy users. Interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum are provided. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at multiple transceivers in a wireless network.

Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that minimizes the probability of interfering with existing legacy users. Interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum are provided. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at multiple transceivers in a wireless network.

Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that will minimize the probability of interfering with existing legacy users. The invention provides interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at a multiplicity of transceivers in a wireless network.

Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that will minimize the probability of interfering with existing legacy users. The invention provides interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at a multiplicity of transceivers in a wireless network.

Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that will minimize the probability of interfering with existing legacy users. The invention provides interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at a multiplicity of transceivers in a wireless network.

Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that will minimize the probability of interfering with existing legacy users. The invention provides interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at a multiplicity of transceivers in a wireless network.

Abstract: An optical vector modulator includes an information generator that generates a plurality of N-bit streams at an output where each of the plurality of N-bit streams represents a desired modulation point in a signaling constellation. A memory look-up table having an N-bit address input retrieves a first and a second stored value that corresponds to the N-bit address input, where each of the first and the second stored value represent a respective one of a first and a second modulation vector of a desired modulation point in the signaling constellation. A first and a second digital-to-analog converter generates first and second analog signals, respectively, that correspond to respective ones of the first and second modulation vectors of the desired modulation points in the signaling constellation. A dual-drive interferometric modulator modulates the first and the second analog signals on the optical beam to obtain the desired modulation points in the signaling constellation.

Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that will minimize the probability of interfering with existing legacy users. The invention provides interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at a multiplicity of transceivers in a wireless network.

Abstract: An optical vector modulator includes an information generator that generates a plurality of N-bit streams at an output where each of the plurality of N-bit streams represents a desired modulation point in a signaling constellation. A memory look-up table having an N-bit address input retrieves a first and a second stored value that corresponds to the N-bit address input, where each of the first and the second stored value represent a respective one of a first and a second modulation vector of a desired modulation point in the signaling constellation. A first and a second digital-to-analog converter generates first and second analog signals, respectively, that correspond to respective ones of the first and second modulation vectors of the desired modulation points in the signaling constellation. A dual-drive interferometric modulator modulates the first and the second analog signals on the optical beam to obtain the desired modulation points in the signaling constellation.

Abstract: An optical data transmitter includes a symbol generator that generates a stream of symbols having a symbol rate. A Nyquist filter that is electrically connected to the symbol generator generates a Nyquist filtered stream of symbols. An optical modulator modulates an optical beam with the Nyquist filtered stream of symbols to generate a modulated optical beam. The symbol rate is greater than a bandwidth of the modulated optical beam.

Abstract: An ultra-wide band (UWB) radio frequency (RF) receiving device (205) includes a first receiver (305) that receives UWB RF signals, a second receiver (315) that receives an external cue, and a processing unit (330). The second receiver (315) receives an external cue that includes one of a television blanking signal, a zero-crossing of a FM radio transmission, a paging system signal, a zero-crossing of an analog voice transmission, a zero-crossing of an analog video transmission, a cellular telephony control channel signal, a cellular telephony traffic channel signal, a digital sub-band for an AM or FM radio station signal, a digital or analog signal in a short-wave-radio transmission, a digital television signal, a digital or analog signal in a land mobile radio transmission, a radio-navigation signal, a radar signal, a satellite signal, an acoustic event or signal, a magnetic event or signal, or an optical event or signal.

Abstract: A wireless network [100] includes a number of first wireless terminals configured to operate as cluster heads [110] by communicating with at least one other cluster head over a relatively long range backbone link [115]. Each one of the first wireless terminals includes a backbone transceiver. The backbone transceivers may operate in a first frequency range. At least one second wireless terminal is configured to operate as a cluster member [120] by communicating with an associated cluster head over a local link. Each one of the second wireless terminals includes a cluster transceiver. The cluster transceivers may operate in a second frequency range that is different from the first frequency range of the backbone transceivers. At least one of the first and second wireless terminals includes both a backbone transceiver and a cluster transceiver.

Abstract: Method and apparatus for detecting whether router status information sent from a first router is unreliable, includes structure and/or steps for storing a router status database. Structure and/or steps are provided for receiving a first signal corresponding to a first router status message sent by the first router, the first router status message containing router status information indicative of the status of communication between the first router and a second router. Further, structure and/or steps are provided for issuing an alarm signal if the signal comparison reveals that the first and second router status messages contain non-complementary router status information. Such information can be flooded through the network to isolate the unreliable/compromised router.

Abstract: According to the principles of the invention, there is provided a system, apparatus, and method for detecting spurious network traffic. In a system according to the principles of the invention, a switch such as a router constructs a routing tree for each other switch connected thereto. When a network packet is received, the switch inspects the source address of the packet, and determines whether the forwarding switch or network interface could be expected to deliver a network packet from the indicated address. If it appears from this analysis that the network packet should not have come from the forwarding switch, then certain measures may be taken to address the situation. For example, the network packet may be dropped, an alarm may be generated to the forwarding switch, or an alarm may be generated to an automated or human network supervisor.

Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that will minimize the probability of interfering with existing legacy users. The invention provides interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at a multiplicity of transceivers in a wireless network.

Abstract: A navigation system for an unmanned ground vehicle (UGV) includes an MPEG encoder that pre-processes frame data from a plurality of cameras on the UGV before the data is used to generate maps that identify objects in the vehicle's field of view and that identify terrain characteristics. The MPEG encoder converts the red-green-blue (RGB) data into luminance-chrominance (YUV) data. The luminance and chrominance data for each frame are divided into blocks for determining motion vectors, average chrominance values, and spatial frequencies for each block. A range map identifying objects is generated from the motion vectors and average chrominance values, and a slope map identifying terrain characteristics is generated from the spatial frequencies.

Abstract: The present invention increases the available spectrum in a wireless network by sharing existing allocated (and in-use) portions of the RF spectrum in a manner that will minimize the probability of interfering with existing legacy users. The invention provides interference temperature-adaptive waveforms, and a variety of physical and media access control protocols for generating waveforms based on measurement and characterization of the local spectrum. The invention measures the local spectrum at a receiving node, generates an optimal waveform profile specifying transmission parameters that will water-fill unused spectrum up to an interference limit without causing harmful interference to primary and legacy transmitters using the same frequency bands, and enables simultaneous transmit and receive modes at a multiplicity of transceivers in a wireless network.