A method and system for providing session admission control for a new session in a broadband wireless network is provided. Embodiments of the present invention may comprise detecting a first modulating signal at a first wavelength, detecting a second modulating signal at a second wavelength, and determining a relative amplitude of the first and second modulating signals. A substrate is positioned over the electrode. The ejection roller is configured to move the restriction member to the restriction position by rotating in the forward direction, and to move the restriction member to the retracted position by rotating in the reverse direction. forming a two-stage polymer dispersion by adding to the at least partially neutralized first stage polymer a second stage monomer mixture and emulsion polymerizing said second stage monomer mixture to a second stage polymer which is less hydrophilic than the first stage polymer,d. The system includes a console, which contains all motors, pumps, sensors, valves and control circuitry, and a unique disposable set that includes a cassette supporting a centrifuge with an improved design, pump interfaces with an improved design, component and solution bags, and tubing.