Abstract: A communications system includes a transmitter for transmitting an optical signal including a plurality of data streams over an optical communications link. The transmitter includes first signal processing circuitry for processing each of the plurality of input data streams to generate a parallel pair of data streams including an in-phase stream (I) and a quadrature-phase stream (Q) for each of the plurality of input data streams. The first signal processing circuitry modulates a first and second parallel pair of data streams with a selected one of at least three mutually orthogonal functions at a first and second signal widths, respectively, to generate a plurality of first data sub-layers and a plurality of second data sub-layers and generates a plurality of composite data stream by overlaying the first data subs-layers with the second data sub-layers at a preconfigured overlay offset.

Abstract: Signal generation circuitry generates a first signal having at least one orbital angular momentum applied thereto and applies the first signal to the sample. A detector for receives the first signal after it passes through the sample and determines the concentration of the material within the sample based on a detected value of orbital angular momentum with the first signal received from the sample.

Abstract: A method for transmitting a plurality of input streams from a transmitting unit to a receiving unit receives the plurality of input data streams and each of the plurality of input data streams are processed to generate a parallel pair of data streams including an in-phase stream (I) and a quadrature-phase stream (Q) for each of the plurality of input data streams. A first and second parallel pair of data streams are modulated with a selected one of at least three mutually orthogonal functions at a first and second signal widths, respectively, using a predefined modulation process to generate a plurality of first data sub-layers and a plurality of second data sub-layers. A plurality of composite data stream are generated by overlaying the first data subs-layers with the second data sub-layers at a preconfigured overlay offset. The plurality of composite data streams are overlapped by a predetermined overlap amount and placed on a wavelength of a communications link.

Abstract: A method is disclosed for completing a roaming cellular call between a roaming subscriber and another party. The first step is initiating the roaming call between the roaming subscriber and the another party. The roaming subscriber is provided with a prepaid debit account. The roaming subscriber is then connected to a cellular network when a connection between the subscriber and the another party is to be made such that a call has been built over a calling network. The prepaid debit account of the roaming subscriber is then examined to determine the balance thereof, and then the roaming subscriber is informed of financial information regarding the call connection prior to connecting the roaming subscriber to the another party over the already built call.

Abstract: A method is disclosed for completing a roaming cellular call between a roaming subscriber and another party. The first step is initiating the roaming call between the roaming subscriber and the another party. The roaming subscriber is provided with a prepaid debit account. The roaming subscriber is then connected to a cellular network when a connection between the subscriber and the another party is to be made such that a call has been built over a calling network. The prepaid debit account of the roaming subscriber is then examined to determine the balance thereof, and then the roaming subscriber is informed of financial information regarding the call connection prior to connecting the roaming subscriber to the another party over the already built call.