Described is an apparatus for calibrating a position finding device, having a comparer for comparing a received radio signal pattern to a multitude of reference radio signal patterns, a determiner for determining a signal strength difference, and a determiner for determining a calibration value. The liners have edges extending in contacting relationship with the edge portions of the side posts in connected relationship. The example method may also include selectively storing a control packet security indicator sniffed from a control packet network communication in response to determining that a match exists between a control packet identification field and a QoS database entry. Individual members of the group may or may not have existing internet presences.