This invention describes a protective device and associated method for protecting a mobile terminal whether or not the terminal is in use, and for providing a hands-free operation of the mobile terminal, wherein the mobile terminal can be a mobile phone, a personal digital assistant, a pager, a MP3 player, or any similar portable communication device or a mobile electronic device. 5 to 100 parts by weight of vegetable oil per part by weight of sitosterol. Each node also includes a memory configured to store at least one respective propagation delay parameter related to a signal propagation delay between the central controller and the node.