A system and method includes steps, or acts, of: defining one or more events to provide a unified specification; registering one or more events to be detected; detecting an occurrence of at least one of the registered event or events; generating a monitoring entry each time one of the registered events is detected; and entering each of the monitoring entries generated into a single logical entity. Selectively assigning channels to wavelengths having desirable gain characteristics for a given amplifier permits channels to be more closely spaced in the available frequency spectrum. The bleed valve is configured to move from the closed position to the open position in response to an adjustment of the height adjustment mechanism. By this means it is possible to suppress interference to a communication terminal apparatus that performs adaptive modulation communication with another base station apparatus and a communication terminal apparatus that performs adaptive modulation communication with the local base station apparatus at the same time.