DETERMINING METHOD, COMPUTER PRODUCT, DETERMINING APPARATUS, AND DETERMINING SYSTEM

A determining method executed by a processor includes obtaining distance information that indicates a distance between monitoring apparatuses disposed to encompass a given area in which wireless communications apparatuses are scattered; causing a wireless signal to be transmitted and received between the monitoring apparatuses by multi-hop communication among the wireless communications apparatuses; calculating an estimated distance between the monitoring apparatuses, based on a hop count of the wireless signal multi-hop communicated among the monitoring apparatuses; and making a determination concerning a vacant area in which none of the wireless communications apparatuses is present, based on a result of comparison of the distance indicated by the obtained distance information and the calculated estimated distance.