Abstract: A central management system polls a lighting node in a mesh lighting network, sending a command message for the node to measure a link quality indication (LQI) of the received command message. The node returns a status message, including in its payload the measured LQI. The management system computes from the node's status messages, a statistical characterization of the link quality of the node and compares it with a threshold quality value. If the comparison indicates sufficient degradation in link quality, the management system automatically transmits a disconnect command to the node. In response, the node disconnects and enters a discovery mode to find a better quality link to rejoin the network. In example embodiments, the lighting node may also report its illumination and operational status in the payload of the status message, along with the LQI, enabling the management system to determine whether illumination by the node is failing.

Abstract: Example embodiments of the invention efficiently organize, control and prioritize a distributed lighting network. A mesh lighting network is organized from the bottom up into groups of lighting devices with control signal repeaters fanning out control signals to each group. Each lighting device is capable of forwarding control signals to additional lighting devices. During build-out of the mesh network, as new lighting devices are installed, the control network automatically selects a device whose repeater function will provide the most reliable and efficient distribution of control signals to the new group of devices being installed.

Abstract: Example embodiments of an invention to efficiently organize and control a distributed lighting network. A process supports message flows and an interface to facilitate the organization and control a very large array of intelligent lighting nodes. Each newly installed lighting node broadcasts an initial contact message that includes fields specifying requests, such as lighting schedule, intensity, color, aiming direction, flood lighting, etc. A central controller receives the message at a discovery message and provisioning request interface, commissions the lighting node, and processes the provisioning requests.

Abstract: An improved per-tone FEQ method with a noise reduction technique using periodic training pilot tones increases the throughput for long-reached modems. This method can reduce the noise effects in estimating FEQ equalizer coefficients. Each per-tone FEQ can be estimated by using the periodic training signals and an averaging technique to remove noise from each sub-channel (EQN. VI). After solving the system equations (EQN. IV), per-tone equalization coefficients of the FEQ equalizer for each group can be combined to obtain the optimized results in the form of the Toeplitz matrix (EQN. V). Each element within the Toeplitz matrix can be derived from the averaging technique used to remove noise from each sub-channel (EQN. VI). To demodulate a signal with the Toeplitz matrix, an inverse of every element in a row of the Toeplitz matrix is taken and multiplied by the sending signal which creates an N Log N matrix.

Abstract: The method and apparatus in accordance with the present invention provides signal-to-noise ratio improvement through noise reduction by means of spectral averaging and subcarrier based averaging techniques.

Abstract: A quadrature amplitude modulation implementation incorporating a symmetric spherical quadrature amplitude modulation constellation. The symmetric spherical quadrature amplitude constellation, as displayed in a multi-dimensional complex plane, is bounded by a surface comprising all symbol points at a predetermined distance from a center point and coincident with the intersection of at least two axes, and exhibiting correspondence in relative position of the symbol points on opposite sides of the at least two axes.

Abstract: The present invention discloses an improved initialization method for modem communication wherein the timing offset required for synchronization is estimated utilizing an entire received DMT frame and the channel impulse response is estimated utilizing the pilot tones received within the same DMT frames utilized for synchronization.

Abstract: An improved per-tone FEQ method with a noise reduction technique using periodic training pilot tones increases the throughput for long-reached modems. This method can reduce the noise effects in estimating FEQ equalizer coefficients. Each per-tone FEQ can be estimated by using the periodic training signals and an averaging technique to remove noise from each sub-channel (EQN. VI). After solving the system equations (EQN. IV), per-tone equalization coefficients of the FEQ equalizer for each group can be combined to obtain the optimized results in the form of the Toeplitz matrix (EQN. V). Each element within the Toeplitz matrix can be derived from the averaging technique used to remove noise from each sub-channel (EQN. VI). To demodulate a signal with the Toeplitz matrix, an inverse of every element in a row of the Toeplitz matrix is taken and multiplied by the sending signal which creates an N Log N matrix.