Abstract: A method is provided that includes selectively engaging impedance circuits one at a time from a plurality of selectable impedance circuits in-line with a communication channel. Each of the plurality of selectable impedance circuits includes a hybrid circuit responsive to a modem and to the communication channel. The method further includes determining a performance characteristic for each of the impedance circuits and selecting one of the plurality of selectable impedance circuits for transmission based on the respective performance characteristic.

Abstract: An XDSL system comprising a hybrid circuit in operative communication with a transmission line and an XDSL modem associated with a subscriber premises. The hybrid circuit comprises a plurality of selectable impedance circuits having different impedance values. A controller selectively engages each of the impedance circuits in-line with the XDSL modem and the transmission line. The controller records the performance of the modem with each circuit engaged, and selects the desired impedance circuit as a function of the performance characteristics associated with each of the impedance circuits. The impedance circuit which provides the best performance characteristic is selected as the impedance circuit for normal modem operation.

Abstract: An XDSL system comprising a hybrid circuit in operative communication with a transmission line and an XDSL modem associated with a subscriber premises. The hybrid circuit comprises a plurality of selectable impedance circuits having different impedance values. A controller selectively engages each of the impedance circuits in-line with the XDSL modem and the transmission line. The controller records the performance of the modem with each circuit engaged, and selects the desired impedance circuit as a function of the performance characteristics associated with each of the impedance circuits. The impedance circuit which provides the best performance characteristic is selected as the impedance circuit for normal modem operation.

Abstract: A circular internal combustion engine includes a torque shaft, a central cam connected to the torque shaft, a stationary middle ring located about the central cam, and, an exhaust ring assembly located about the middle ring and connected to the torque shaft and the central cam. The middle ring provides stationary support for power chambers located between the central cam and the exhaust ring. Power shuttle assemblies utilize thermal energy from the power chambers to apply leverage on surfaces of the central cam and exhaust ring to provide rotational force.