Provided are diffused but transmissive optical image projection screens and methods of their manufacture, including screens comprising acetal polymers such as polyoxymethylene. At start-up of the transmission power amplifier unit, a controller determines whether the base-station apparatus is in a blossoming mode or breathing mode, maximizes gain of the transmission power amplifier unit by controlling the gain varying unit if the mode is the blossoming mode and increases the gain gradually in proportion to the passage of time if the mode is the breathing mode. The WINS NG nodes combine microsensor technology, low power distributed signal processing, low power computation, and low power, low cost wireless andor wired networking capability in a compact system.