Location systems for locating objects or personnel within a facility and their use in conjunction with telephone systems have previously been proposed. Typically, location systems locate personnel or objects by seeking out where the objects or personnel are closest to designated monitors. Such systems generally include a central controller connected to a plurality of transceivers distributed at designated locations throughout a facility. Portable units are worn or attached to objects or personnel to be located. Each portable unit is assigned a unique identification. In some systems, the central controller causes the transceivers to broadcast or page the portable unit by its identification. The broadcast or page signal is received by the portable units but only the portable unit having a matching identification will respond with a confirmation signal, which is received by the transceiver located closest to the responding portable unit. The transceiver in turn reports to the central controller that it has received a confirmation signal. The location of the portable unit is determined by the central controller by the message received from the transceiver. Location systems employing such location technique are described, for example, in U.S. Pat. No. 4,649,385 to Aires et al.; and U.S. Pat. Nos. 3,805,265, 3,805,227 and 3,696,384 to Lester.
The proposed use of locator systems in conjunction with telephone systems have usually been in the form of locating the called party and automatically ringing the telephone closest to the called party. While such systems would significantly reduce the "phone tagging" problems, (i.e., the calling and called parties repeatedly calling each other without an actual conversation, which are common in office facilities), numerous problems associated with the use of telephones remains. For example, a busy called party who does not wish to answer the phone, who does not want to be disturbed or who wishes an opportunity to screen a caller, must nevertheless take the call. An automatic PBX/locator system may also be the cause of other problems, for example, the automatic routing of a call to a telephone in a conference room, causing disruption to an important meeting.
Therefore, a need exists for a telephone/locator system which provides advanced features to address the above problems and to facilitate interaction and control of the system by the users.