Abstract:
An elapsed time reminder system for a telecommunication network provides elapsed time reminder service to a party participating in a call in the network. A call state processing component processes requests for elapsed time reminder service from the requesting party. An elapsed time reminder interval may be specified by a requesting party, or a default interval may be used. When the service is invoked, a timer is reset to monitor call duration. When the reminder interval is reached, an elapsed time reminder announcement is played to the requesting party.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to voice communications in a telecommunication network. More particularly, the invention pertains to the monitoring of calls and the selective presentation of call information to call parties. 
     2. Description of the Prior Art 
     In a conventional telecommunication network, such as the Public Switched Telephone Network (PSTN), parties participating in a voice call are generally not able to monitor call duration unless they time the call themselves. Although callers using pay telephones or prepaid calling cards will receive a warning when their authorized telephone time is nearing an end, they are not told how long an active call has been in progress. 
     As a result, callers who make long distance calls, 900 charge calls, etc., or who receive collect calls, can incur significant telephone charges if they fail to pay attention to the length of the call. What would be desirable is a system for providing a warning or notification to a call party that serves as an indication of call duration. Such a system should preferably be available at the outset of a call as well as during a call, and should be available to each of the call parties, or at least the party who will be billed for a call. 
     SUMMARY OF THE INVENTION 
     A solution to the forgoing problem and an advance in the art is provided by an elapsed time reminder system for a telecommunication network. The elapsed time reminder system provides elapsed time reminder service to a party participating in a call in the network. A call state processing component of the elapsed time reminder system processes requests for elapsed time reminder service. An elapsed time reminder interval may be specified by a requesting party, or a default interval may be used. After the service is invoked, a timer is reset to monitor call duration. When the reminder interval is reached, an elapsed time reminder announcement is played to the requesting party. 
     Elapsed time reminder service can be provided in response to a request made by the requesting party at call initiation or during mid-call. The requesting party may either be a call originator or a call recipient. If service is requested at call initiation, the timer is preferably not reset until the call is connected between both parties. If service is requested during mid-call, the timer is preferably not reset until the call is reconnected following the request for service. Whether the elapsed timer reminder service is provided at call initiation or during mid-call, the service can be invoked based on digits dialed by the requesting party. These service invocation digits may include a service code and an elapsed time reminder period. 
     In its preferred embodiments, the invention is implemented using the existing IN (Intelligent Network) infrastructure of modern telephone networks, with appropriate modifications being made thereto. In particular, it is contemplated that there will be one or more service control points providing Intelligent Network services on behalf of switching nodes that setup calls between call originating and call terminating equipment. To provide elapsed time reminder service, the switching nodes are adapted to receive a service code and an elapsed time interval period value from the requesting party. The receiving switching node routes the service code and the elapsed time interval value to a service control point providing Intelligent Network services to the switching node. The service control point processes the service code and the elapsed time interval and then sends a timer reset request back to the switching node. The timer reset request contains a timer identifier and the elapsed time interval value specified by the requesting party. At the switching node, a timer corresponding to the timer identifier is reset. An elapsed time announcement is then generated whenever the timer reaches the elapsed time interval value. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The foregoing and other features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying Drawing, in which: 
     FIG. 1 is a functional block diagram showing a telecommunication system configured in accordance with the invention; 
     FIG. 2 is a flow diagram illustrating method steps performed in accordance with a first aspect of the invention; and 
     FIG. 3 is a flow diagram illustrating method steps performed in accordance with a second aspect of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning now to the Drawing, FIG. 1 illustrates an exemplary telecommunication system  2  that is configured, according to preferred embodiments of the invention, in a telephone system providing voice communication between customer premises equipment  4  and  6 . The latter are illustrated in FIG. 1 as conventional telephones, but could also comprise ISDN user equipment or the like. The customer premises equipment  4  and  6  respectively connect via LE (Local Exchange) pathways  8  and  10  to switches  12  and  14 . Depending on whether the customer premises equipment  4  and  6  connect via single-user interfaces (e.g., POTS line customer premises drop points) or multiple-user interfaces (e.g., PBX systems, key telephone systems, etc.), the LE pathways  8  and  10  could function as either lines or trunks. The switches  12  and  14  may be conventionally situated at respective telecommunication system central offices or the like. 
     As is conventional, the telecommunication system  2  further includes an Intelligent Network (IN)  16  that assists the switches  12  and  14  to set up call connections on behalf of the subscribers they serve. The IN  16  includes an SCP (Service Control Point)  18  and a pair of SSPs (Service Switching Points)  20  and  22  that are co-located with the switches  12  and  14 . Although not shown, the IN  16  also includes a plurality of packet switches, known as “signaling transfer points” (STPs), that route call signaling messages between the SCP  18  and the switches  12  and  14  as the latter engage in the establishment and termination of call connections. Except to the extent that their programming is modified to provide the functions of the present invention, the foregoing IN components are all conventional in nature. 
     In addition to the IN SSPs  20  and  22 , the switches  12  and  14  also implement the usual OCP (Origination Call Processing) and TCP (Termination Call Processing) functions. More particularly, the switch  12  implements an OCP  24  and a TCP  26 , while the switch  14  implements an OCP  28  and a TCP  30 . Again, except to the extent their programming is modified to assist in implementing the present invention, the foregoing OCP and TCP functions are all conventional in nature. 
     A pair of announcement devices  32  and  34  complete the list of telecommunication system components that can be utilized to perform the functions of the invention. The announcement devices  32  and  34  are respectively connected to the switches  12  and  14 . They are conventional in nature except to the extent that they have been modified to provide elapsed time information in accordance with the invention. 
     In its preferred embodiment, the invention is implemented as a new IN service that shall be referred to as ETR (Elapsed Time Reminder) service. According to this new service, a person operating the customer premises equipment  4  or  6  can request an announcement reminder of the elapsed time for a telephone call, including any ordinary non-prepaid call. ETR service can be invoked on a per-call basis either when dialing a telephone number, or during a call. The service can be invoked by either the calling party or the called party. 
     As described in more detail in the call examples given below, the ETR service disclosed herein utilizes one or more conventional IN TDPs (Trigger Detection Points) that will be defined according to the basic call state model being implemented in the telecommunication system  2 . Assuming that a basic call state model fashioned upon ITU-T (International Telephone Union) recommendation Q.1224 is in use, the TDPs which can be used to provide ETR service include the TDP 3  (Analyze_Information) trigger detection point, the TDP 8  (Originating_midCall) trigger detection point, and the TDP  16  (Terminating_midCall) trigger detection point. The ETR service disclosed herein also utilizes a conventional INAP (Intelligent Network Application Protocol) ResetTimer operation that has been modified to broaden its normal usage. Lastly, the announcement devices  32  and  34  are used to provide ETR service announcement messages. 
     A requesting party can invoke ETR service in two ways, depending on their needs. One way to invoke the service is to prepend a prefix digit string to a dialed telephone number. The prefix digits may comprise a service code and an ETR interval period in minutes. The ETR interval period represents the time interval at which ETR announcements will be played. Another way to invoke the ETR service is during mid-call. This can be done using a hook flash operation followed by entry of digits representing the service code and the elapsed time. An exemplary ETR service invocation digit string has two components, namely, a service code that starts with “*” followed by two digits (e.g., “75”), and two digits representing the ETR interval period. Note that under either of the above ETR service implementation methods, provision may also be made for prompting the requesting party in the event that no ETR interval period is specified when ETR service is invoked. Alternatively, a default ETR interval period (e.g., 10 minutes) could be used. 
     Example 1 
     Invoking ETR Service When Dialing A Call 
     With reference now to FIG. 2, and beginning at the step labeled by reference numeral  40 , a requesting party (A_party) invokes ETR service by dialing “*75xx” followed by the number (B_party number) of a called party (B_party). It will be assumed that A_party uses customer premises equipment  4  and B_party uses customer premises equipment  6  (see FIG.  1 ). In step  42 , a TDP 3  (Analyzed_Information) trigger detection point in the call state model running in the switch  12  triggers for *75 and the SSP  20  sends an InitialDP (Initial Detection Point) operation to the SCP  18 . The InitialDP operation includes a service key (that identifies the ETR service) and a called party number that includes *75xx +B_party_number. 
     Based on the service key information, the SCP  18  sends a ResetTimer operation to the SSP  20  in step  44 . This portion of step  44  is implemented as a conventional INAP ResetTimer operation that has been modified to broaden its normal usage for resetting the default SSP-SCP communication guard timer. In particular, the timer value sent as part of the modified ResetTimer operation contains the ETR interval period value “xx” specified by A_party. A timer ID (Identification) value is also sent as part of the modified ResetTimer operation. This parameter conventionally has a default value of “0” that indicates the SSP-SCP guard timer. For ETR service, this parameter is set to “1,” to specify that an ETR timer is to be set. To complete step  44 , the ECP  18  sends a conventional Connect operation to the SSP  20  with a destination routing address parameter containing the B_party_number. 
     In step  46 , the OCP  24  routes the call to B_party. When B_party answers the call in step  48 , the OCP  24  starts an ETR timer with an ETR interval period of “xx.” In step  50 , when the ETR timer expires, the SSP  20  invokes the announcement device  32  to play a short announcement to A_party indicating that “xx minutes have passed.” The ETR timer is then reset. Subsequent announcements could either indicate that “another xx minutes have passed,” or that “yy total minutes have passed,” with “yy” being the value “xx” multiplied by the number of ETR interval periods that have elapsed. 
     Example 2 
     Invoking ETR Service During a Call 
     With reference now to FIG. 3, and beginning with the step labeled by reference numeral  60 , a requesting _party ) is assumed to receive a collect call from another party (A_party) and is in the talk stage. Again, it is assumed that A party uses customer premises equipment  4  and B_party uses customer premises equipment  6 . In step  62 , B_party presses a hook flash, invokes ETR service by dialing “*75xx,” and then presses hook flash a second time to return to the connection with A_Party. Note that a hook flash can be produced by pressing the hook on a corded telephone or pressing a hook flash button on a cordless telephone. In step  64 , a TDP  16  (Terminating_midCall) trigger detection point in the call state model running in the switch  14  triggers on the first hook flash. This causes the SSP  22  to send an InitialDP (Initial Detection Point) operation to the SCP  18 . The InitialDP operation includes a service key (that identifies the ETR service) and a called party number that includes only *75xx. 
     Based on the service key information, the SCP  18  sends a ResetTimer operation to the SSP  20  in step  66 . This portion of step  66  can again be implemented as a conventional INAP ResetTimer operation that has been modified to broaden its normal usage for resetting the default SSP-SCP communication guard timer. In particular, the timer value sent as part of the modified ResetTimer operation contains the ETR interval period value “xx” specified by B_party. A timer ID value is also sent as part of the modified ResetTimer operation. This parameter conventionally has a default value of “0” that indicates the SSP-SCP guard timer. For ETR service, this parameter is set to “1,” to specify that an ETR timer is to be set. To complete step  66 , the SCP  18  sends a conventional Continue operation to the SSP  22  to close the dialog between the SCP and the SSP. 
     In step  68 , after the SSP  22  receives the Continue operation and the TCP  30  reconnects B_party to A_party. It also starts an ETR timer with an ETR interval period of “xx.” In step  70 , when the ETR timer expires, the SSP  22  invokes the announcement device  34  to play a short announcement to B_party indicating that “xx minutes have passed.” The ETR timer is then reset. Subsequent announcements could either indicate that “another xx minutes have passed,” or that “yy total minutes have passed,” with “yy” being the value “xx” multiplied by the number of ETR interval periods that have elapsed. 
     It will be appreciated that Example 2 could be used when A arty invokes ETR service during a call. In that case, step  64  would cause a TDP (OrginatingMidCall) trigger detection point to trigger in response to the first hook flash. 
     Accordingly, an elapsed time reminder system for a telecommunication network has been described. The disclosed system can be very useful to persons who make charge calls and who may tend to forget about the call length, thereby inadvertently generating large telephone bills. Such persons can now invoke elapsed time reminder service when initiating a call and at any point during a call. The service will also be useful for persons receiving collect calls. 
     While various embodiments of the invention have been disclosed, it should be apparent that many variations and alternative embodiments could be implemented in accordance with the invention. For example, although examples are shown in which ETR service is requested on a per-call basis, it will be appreciated that the service could also be invoked as a service option that applies to multiple calls, or all calls, originated or terminated by a caller. It is understood, therefore, that the invention is not to be in any way limited except in accordance with the spirit of the appended claims and their equivalents.