The present invention provides a mobile phone system, which can give a desired voice message to a user of an opposite party terminal without speaking in a state that limitation to usable voice messages has been reduced, while allowing a user existing under an environment that heshe can not speak to listen to a voice from the opposite party terminal. At least one of a charging bias and a transfer bias is changed between a first area and a second area. Airflow can pass between the plurality of carbon elements and through the carbon filter panel. Caching logic of a given caching unit may include content characterization functionality for generating one or more characterization parameters associated with andor derived from content entering a gateway node with which the given caching unit is integral or otherwise functionally associated.