Protective clothing includes trousers having a leg portion with a distal end, a proximal end, and a knee area that corresponds to a wearer’s knee when the trousers are worn by the wearer. Data included in a cache slot is put \u201con parole\u201d with a first cache hit while waiting for subsequent cache hits. A regular transmission detecting part refers to the transmission history table for every time zone corresponding to the check interval memorized in a setting table.