Patent ID: 7228142

Claim:
A communication terminal apparatus which detects a distance with respect to a connection partner apparatus and limits a predetermined function or notifies that fact thereof to a user in a case when the distance exceeds a predetermined value comprising: communication means for carrying out a wireless communication with a connection partner apparatus by a predetermined wireless communication system; distance detection means for carrying out a distance detection according to a parameter relating to the detection of the distance with respect to said connection partner apparatus; proper distance recognition means for obtaining an information signal to the effect that the distance with respect to said connection partner apparatus is in a predetermined proper distance and for recognizing that it is in a proper distance with respect to said connection partner apparatus; and adjustment means for adjusting said parameter value according to said parameter value when said proper distance recognition means recognized that it is in a proper distance with respect to said connection partner apparatus and said parameter reference value in said proper distance, wherein when a distance with respect to said connection partner apparatus is a predetermined proper distance, the propagation loss is calculated by receiving wireless state information including information of receiving strength and transmission power from said connection partner appartus; the process for recalculating said propagation loss according to the wireless state information sent back from said connection partner apparatus is repeated for a predetermined time period until said propagation loss error falls into a predetermined range; and when said propagation loss error is within a predetermined range, said parameter adjustment is carried out.