This invention relates to a communication service method and an exchange system in a communication network equipped with a function for informing a terminating side of an originating subscriber's number (originating telephone number). More particularly, the invention relates to a communication service method for providing a subscriber with incoming-call logging information, as well as a communication system for implementing this communication service.
An example of a service presently available in telephone and facsimile communications is an originating-call information service through which a user (subscriber) is notified of the circumstances under which a telephone, facsimile machine, etc., was utilized. In accordance with such an originating-call information service, a list of charging information is prepared and provided to the user along with notification of the monthly billing. The list includes, on an outgoing call-by-call basis, when each call was made (the date), to whom the call was placed (the telephone number) and how long the call was (the duration of the call). More specifically, an exchange (the originating exchange) issues an outgoing call from its own subscriber. When communication is established, the exchange creates basic data (the originating subscriber's number, the terminating subscriber's number, communication starting time, call time or communication end time) and transmits the basic data to a billing center. The latter accumulates and edits the basic data, prepares a notification of monthly billing for each user and prepares a list of charging information that is provided to the user. In general a fee is paid for the originating-call information service and the list of charging information is provided only to users who have been registered to receive the service.
With the development of the so-called "information society", there are greater opportunities to utilize communication, as a result of which communication traffic is increasing year by year. When viewed from the circumstances of communication utilization by users, this state of affairs means (a) an increase in the quantity of outgoing calls and (b) an increase in the quantity of incoming calls. Even if the quantity of outgoing calls increases, it is still possible to grasp the circumstances of communication by receiving the above-mentioned originating-call information service. With regard to incoming calls, however, there is no incoming-call information service. Consequently, the user, by his or her own management, can merely ascertain who the caller was and the length of communication (the length of the incoming call). When there is an increase in the quantity of incoming calls, the circumstances under which the calls were terminated cannot readily be grasped. In addition, the method of self-management mentioned above does not make it possible to deal with cases in which an incoming call arrives during communication or in which no response is made to an incoming call (as when an incoming call arrives when the called party is absent). Though an incoming call that arrives during communication or when the called party is absent can be dealt with separately by a call waiting service or a automatic answering telephone service function, the circumstances under which incoming calls were terminated over a certain period (one month, for example) cannot be ascertained systematically.
If an originating subscriber's number, the date and time of an incoming call, the communication conditions (which indicate the distinction between said finish of a call, termination during communication and no response by subscriber) and duration of call can be ascertained, this will be convenient because a customer list can be created with ease and a calling party with which communication could not be established can be called back. Accordingly, the need for a service through which it is possible to acquire logging information of incoming calls is great not only in ordinary households but also in stores, businesses for selling goods via communication services, canvassing companies and the mass media (newspapers and broadcasters).
A system for registering the telephone numbers of incoming calls that arrive when a line is busy is available in the prior art (see Japanese Patent Application Laid-Open No. 4-123648). According to this system, the telephone number of a calling party whose call has arrived during communication is transferred to a terminating telephone, where the telephone number is stored in an internal memory or IC card of the terminating telephone. At the end of the call, the telephone number of the calling party is displayed on a display unit. A call is placed to the calling party based upon the displayed telephone number.
A system for displaying the telephone number of a calling party is also available in the art (see Japanese Patent Application Laid-Open No. 4-137930). In this system, the times at which a wireless terminal is turned off and on are registered at an exchange in advance, and the telephone numbers and call times of calling parties whose incoming calls have arrived at the wireless terminal between the off and on times are stored in a memory. The wireless terminal is notified of this incoming-call information after the terminal is turned on the next time.
However, in the former system, only the originating telephone number of an incoming call that arrives when a line is busy is stored on the side of the terminal. In the latter system, only the originating telephone number of an incoming call that has arrived when the power supply of the wireless terminal is off is stored. As a consequence, the conventional systems do not make it possible to provide a user with a service that allows incoming calls to be logged systematically over any period of time, such as on a monthly basis. In other words, the conventional systems do not make possible a service through which the originating telephone numbers (original subscriber's numbers) of all calls terminated within a certain period, the terminating telephone numbers (terminating subscriber's numbers), date and time of termination and communication conditions (classified by normal finish, termination during communication and no response by subscriber) are stored and this terminating-call information is edited and supplied to each user in response to a request or on a periodic basis.
Furthermore, with the conventional systems, only originating telephone numbers and terminating times are stored; the names and addresses of the calling parties are not. This makes it difficult to specify the parties.