Point-to-point reverse direction phonecalling systems (also known as callback systems) are known in the art. In such systems, when a caller located at a calling telephone dials the number of a called telephone, the system transmits a data message over the telephone network to a remote node instructing the node to place a callback to the calling location. The caller then hangs up. The remote node initiates calls to both the calling telephone and the called telephone and connects these two calls together. Such systems provide considerable savings when the call cost from the calling location to the called location is higher than the call cost from the called location to the calling location, as is often the case with respect to international phone communications.
A long standing problem in the area of callback technology has been that a considerable portion of the period between initiation of a phone call and either completion thereof or determination that the call cannot be completed (because of a no answer or busy signal) has traditionally been treated as non-billable in nature. For example, billing protocols, as they have evolved over time, both in the United States and abroad, only permit billing to the ultimate customer for the period between call completion and call termination as perceived by the ultimate customer. In other words, under such established billing protocols, the ultimate customer cannot be charged for the system time required to ring the called location to determine if the call can be completed. Further, such phone calls do not permit billing for the time between the termination of the phone call as perceived by the caller and the actual stand down time or reset time for the public switched service network. One disadvantage of prior art callback systems has therefore been that when the callback from the central switch to the calling location is successful, but the called party cannot be reached for some reason, the caller cannot be charged for the cost of the callback since the call did not result in a successful connection to the called party. The cost of the callback must instead be born by the company providing the callback service.
In addition, certain environments present unique challenges to implementing a callback system. For example, in a hotel environment, a guest at the hotel has no means of answering a callback directly since the callback must be received by an operator who must know in advance who the call is for and where to transfer it to. This difficulty, plus other factors relative to billing procedures in hotels, has prevented most major hotels from employing international callback services. Similar problems are encountered by other large facilities such as hospitals, industrial installations, governmental sites and telephone companies themselves.
Another problem which can increase the cost of operating a callback system is that of reverse answer supervision after a call termination, or the lack thereof. That is, without a call completion signal after call termination transmitted back from the calling location to the originating switch which placed the callback, it can be difficult for the originating switch to know when a call is finished. As a result, the originating switch may maintain the callback connection after the caller has terminated his call. This can have devastating consequences to the callback operator who may incur charges for callback time which cannot be passed on to the caller.
The invention disclosed in U.S. patent application Ser. No. 08/320,269, filed on Oct. 11, 1994 (the '269 application), provides a solution to the above problems and, additionally, provides a means by which hotels, and other similarly situated establishments, can make use of international callback technology and, further, can do so on a more profitable basis than had been available to any prior user of such technology.
The method disclosed in that application comprises in part the steps of transmitting the identification numbers of a calling party and a called party to a central switching unit which then interrogates the called location to obtain the call supervision status thereof. If the call status is that of an answer, the central switching unit completes a first phone-call from the switching unit to the called location and originates a second phone call through the telecommunications network to the calling location. Upon completion of both phone calls, the two are teleconferenced, thereby placing the calling and called parties in communication with each other. However, if the call status at the called-location is that of a no answer or busy, an uncompleted call status signal is provided to the central switching unit. Thereafter, the central switching unit either transmits a call status signal through said independent transception channel to the local communications node to inform the calling location that the call cannot be completed or, alternatively, the central switching unit sends no status signal whatsoever. In the latter case, a predetermined interval of silence from the central switching unit is interpreted by the local communications node to mean that the call could not be completed. The system then sends an appropriate advisory to the calling party.
While the invention disclosed in the '269 application represents a significant improvement over the prior art, it does not adequately solve all problems associated with callback technology. Specifically, because the system disclosed in the '269 application does not initiate the callback until the called telephone has been answered, a delay must be endured while the system establishes the callback connection to the calling location.
Moreover, in the system disclosed in the '269 application, the callback experience may at times not identically match that of a call placed directly from the calling telephone to the called telephone. For example, in the system disclosed in the '269 application, when the called telephone is busy, the caller receives a message to that effect rather than hearing the appropriate busy signal for the called location as he would had the call been placed directly from the calling telephone to the called telephone.
This is important because certain telephone operators may not use the callback system if it alters the calling experience in any way.