Abstract:
Advertising system for callers to busy numbers. When a call is received for a busy directory number the originator is notified and a determination is made as to whether the originator would like to activate an automatic callback feature. If the originator has activated the feature the call is forwarded to an advertisement server and the directory number is monitored. When the called directory number is free the originator is connected. In effect, an automatic callback service is provided free of charge to a caller, the revenues from the advertising paying for the service. The invention can be implemented either with an automatic callback facility or by using advanced intelligent network triggers. Computer program code within a telecommunication switch is used to implement the invention.

Description:
BACKGROUND 
     1. Field of the Invention 
     This invention is related to the use of advertising to pay for telecommunication services. In particular, this invention is related to the use of advertising to pay for an automatic callback feature for busy directory numbers. 
     2. Description of the Problem 
     Telecommunication today on the Public Switched Telephone Network (PSTN), is marked by the proliferation of numerous services to provide convenience to users. Among these services is automatic callback, through which a caller to a busy directory number (DN) can have the number monitored. When the DN becomes free, the originator of the call is automatically called back by the PSTN. When the originator picks up the callback, the DN which was called is rung. In this scenario, a PSTN switch between the originator and the telephone associated with the DN offers to keep trying the busy number for an additional cost. 
     FIG. 1 illustrates how the automatic callback feature works. According to FIG. 1, a caller or originator,  110 , attempts to call equipment,  114 , associated with a busy DN. End office switch  112  serves the telephone equipment,  114 , associated with the busy DN. At  101  the caller dials the called party DN. At  102  and  103  the switch attempts to establish a connection with the called party DN and receives an indication that the called party is busy, or that the telephone that the called party is using is off-hook. At  104  the end office switch plays a message asking the caller if the caller would like to be notified when the called party becomes idle. If the caller accepts, the end office switch,  112 , activates a feature called automatic callback (ACB). ACB is defined for POTS (plain old telephone system) in Telcordia (formerly BELCORE) standard TR-NWT-000215, Issue 3, June 1993, and for ISDN (integrated services digital network) in Telcordia standard TR-NWT-000855, Issue Jun. 3, 1993, both of which are widely distributed and available from many technical libraries, or can be ordered from Telcordia Technologies, Inc. The ACB facility monitors the line state of the telephone line associated with the called DN to determine if the line is busy or idle. When the called party becomes idle, the caller is notified and a call is established between the two agents. 
     The automatic callback feature, while extremely useful and beneficial, is under-utilized because many users of the PSTN do not want to pay the fee associated with the use of the feature. Telephone companies do not wish to provide the feature for free and forfeit the revenue currently realized through collecting charges for the feature. The use of advertising to pay for goods and services is already well known. In addition the idea of targeting advertising to users of the Public Switch Telephone Network is known. International patent application number PCT/US98/08087, published on Dec. 10, 1998, under the publication number WO 98/56154 discusses the targeting of advertising to users of a telecommunication network. What is needed is a way to pay for automatic callback service through the use of advertising, so that users do not have to pay for the service and telephone companies still realize revenue from providing the service. 
     SUMMARY 
     The present invention meets the above needs by providing an advertising system for users of the PSTN. Using the present invention, a caller to a busy DN is provided with the option of listening to advertising messages while waiting for a switch which serves the called DN to try the called number and make a connection when the called number is no longer busy. The provider of the telephone services for the caller sells advertising time on the service to maintain a revenue stream from providing the automatic callback service. 
     According to the present invention a switch which is implementing the service first receives a call from the originator which is destined for a directory number which is busy. The switch notifies the originator of the busy directory number and determines if the originator has activated the automatic callback feature according to the invention. If the originator has activated the feature, the call is forwarded to an advertisements server and the DN is monitored. When the DN is no longer busy the originator is connected. According to one embodiment of the invention the call is processed using the automatic callback (ACB) facility. According to another embodiment of the invention the call is processed using an advanced intelligent network (AIN) trigger. 
     The invention is typically implemented using a computer program product for the equipment involved. A computer program product includes a media with computer program code which causes the systems involved to perform the necessary operations. A switch which implements the invention includes a switching matrix, one or more peripheral modules connected to the switching matrix, one or more input/output devices connected to the switching matrix, and a processor core which controls the operation of the switch and, during operation, contains the computer program code which implements the invention. 
     The telecommunication network in which the invention operates includes the originator customer premises equipment, the destination customer premises equipment (CPE) which is associated with the called DN, and one or more switches disposed between the originator and destination CPE. At least one of the one or more switches includes the computer program code which implements the invention. Usually, the invention will be implemented at the end office switch. An advertisements server which contains the audio advertisements stored on a media, is connected to the switch which implements the invention. Where AIN is used to implement the invention, the switch is also connected to a service control point (SCP). 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a network diagram showing the network and messaging of the prior art. 
     FIG. 2 is a network diagram showing the operating environment and messaging according to one embodiment of the present invention. 
     FIG. 3 is a network diagram showing the operating environment and the messaging according to another embodiment of the present invention. 
     FIG. 4 is a block diagram of a telecommunication switch which implements some aspects of the present invention. 
     FIG. 5 illustrates a media on which computer program code which implements the present invention is stored. 
    
    
     DETAILED DESCRIPTION 
     FIG. 2 illustrates the operation of the invention according to one embodiment. According to FIG. 2, a caller or originator,  210 , is connected to end office switch  212  which is in turn connected to equipment associated with a called directory number (DN),  214 . As a practical matter end office switch  212  is only directly connected to the originator  210  if both the originator and the called DN are served by the same switch. However the operation of the invention is the same regardless of whether there are intervening switches between end office switch  212  and the caller,  210 . The additional switches are omitted for simplicity. An advertisement server,  216 , is also connected to the network. The reference numbers in circles illustrate the various steps in the processing required to implement the invention. 
     At  201  the caller dials the called party DN. The switch attempts to establish a connection with the called party at  202  and receives a busy indication at  203 . There are numerous ways in which PSTN switches determine and keep track of which DN&#39;s are busy and which are free. In some cases the switch maintains a busy/idle map of all lines. The map is dynamically updated and is stored in the switch&#39;s memory. Some switches use messaging between the computing module or processor core and the various peripheral devices within the switch to determine if a line is busy. 
     At  204  a busy announcement is transmitted to the caller and the caller is asked if they wish to listen to advertisements and be automatically connected to the called DN when the called DN becomes free. In this embodiment, when using a traditional or (POTS) telephone the user indicates his or her willingness to listen to advertisements in return for activating the automatic callback feature through a touch-tone code entered at the telephone terminal. It is also possible to use voice recognition to provide input. Other options such as using telephones with special text messaging capabilities or with full alpha-numeric keyboards can be implemented. When the user selects the feature, the call is forwarded to an advertisement server at  205 . Advertisements are played back to the user at  206 . All the while, a feature inside the switch,  207 , is monitoring the status of the called DN. As soon as the called party becomes idle the feature inside the switch signals the advertisement server to release the call at  208 . The caller is notified at  209  via an announcement that the called party is idle and the called party and calling party are connected. In the present embodiment of the invention, the feature in the switch which monitors the busy status of the DN and forwards the call to the advertisement&#39;s server is the automatic callback (ACB) facility. 
     The advertisement&#39;s server which is used with the present invention will typically be implemented on a workstation or computer having sufficient storage media to store all of the various advertising messages. The advertisement&#39;s server can be interfaced with the switch in many ways. If the switch is an Integrated Services Digital Network (ISDN) switch, the interface will probably be a primary rate interface (PRI) trunk. In this case, the signaling used will follow the well-known international telecommunication&#39;s union (ITU) Q.931 standard. The interface can also be an ISDN user part (ISUP) trunk which implements messaging via a signaling system 7 (SS7) network. In a telephony network using voice over internet protocol architecture the advertisements server may be connected through a gateway using ITUH.323 signaling, or a similar voice over IP type of signaling. 
     FIG. 3 illustrates another embodiment of the present invention. In FIG. 3 the caller is represented by customer premises equipment (CPE),  320 . The caller CPE is connected to end office switch  328  which is in turn connected to telephone equipment  322  associated with the called, busy DN. As before switch  328  is connected to the advertisement server,  326 . Switch  328  is also connected to a service control point (SCP),  324 , which is further explained below. Also as before, reference numbers and circles indicate steps in the processing which is necessary to carry out the invention. 
     In the embodiment of FIG. 3, advanced intelligent network (AIN) triggers are used to implement the automatic callback feature. With AIN, a signaling network is disposed in parallel with the telecommunication network which carries voice and/or data traffic. In such a network a switch serves as a service switching point, or SSP. A service switching point processes AIN triggers. Most typically, the signaling system 7 (SS7) protocol is used to exchange information on the AIN. Databases containing information used to respond to queries which are triggered at an SSP are contained in a service control point (SCP). A trigger is a process that identifies calls that need AIN processing. When encountering a trigger, an SSP suspends normal call processing and sends a query. Such a trigger can be used to implement the present invention. 
     In this embodiment the invention uses a T_BUSY trigger for residential lines. In this case the originating agent, the caller, attempts to call a terminating agent which is busy. The end office switch which serves the terminating agent is enabled to process the T_BUSY trigger. Turning again to FIG. 3, at  301  the originator dials the terminator DN. The end office,  328 , attempts to establish a connection with the called party at  302  and determines at  303  that the called party is busy. The T_BUSY trigger is detected. The calling party does not hear a busy indication at this point. The T_BUSY trigger causes a query to be sent to the SCP at  305 . The end office switch still does not provide the busy indication to the calling party, but rather waits for instructions from the SCP. At  306  the SCP sends a response message to the switch with instructions on how to process the call. In the present embodiment the response directs the end office switch to determine if the caller or originator wishes to activate the automatic callback feature at  307 . If so the call is then forwarded to the advertisement server,  326 , at step  308 . The advertisement server is connected to the end office switch through any of the same interfaces previously described, including ISUP, SS7, or H.323. Advertisements are now played to the caller at  309 . 
     The switch monitors the state of the busy DN at  310 . As soon as the called party becomes free the switch signals the advertisement server to release the call at  311 . The user is notified at  312  that the called party is idle and the two agents are connected. 
     FIG. 4 illustrates a conceptual, functional block diagram of a switch which implements the invention. Processor core  402  includes a central processing unit memory and supporting circuitry. In some switch architectures the processor core is called the computing module. This processor core, together with any computer program code stored in memory is the means for controlling the overall operation of the switch. Switching matrix  401  allows the processing core to communicate with the other components. The switching matrix,  401 , includes one or more buses and accompanying internal circuitry. Input/Output (I/O) module  605  is also connected to the switching matrix and includes removable media devices to load computer program code. The I/O module also includes devices for connection to work stations and similar equipment. The peripheral modules,  603 , are connected to the switching matrix,  601 , and are managed by the processor core,  602 . The peripheral modules,  603 , provide an interface to various networks including various types of line interfaces, as well as interfaces to CPE. It should be noted that the computer program code which implements the invention can be stored and executed within the switch itself, or in another device. For example some of the computer program code could be stored and executed by the advertisement&#39;s server, or by an auxiliary device connected to the switch via the AIN. 
     Appropriate computer code in combination with hardware implements many of the elements of the present invention. The computer program code is often stored on a storage media. This media can be a diskette, hard disk, CD-ROM, or tape. The media can also be a memory storage device or collection of memory storage devices such as read-only memory (ROM) or random access memory (RAM). Additionally, the computer code can be transferred to the switch over some type of data network. FIG. 5 illustrates one example of a media. FIG. 5 shows a tape cartridge of the type where magnetic media  501  is enclosed in a protective cassette,  502 . Magnetic field changes over the surface of the magnetic media,  501 , are used to encode the computer program code. In this way the computer program code is stored for transport and later retrieval. 
     It should be noted that because computer program code is used to implement the invention, there is an infinite variety of ways to handle specific details of the invention. There are also numerous types of switching systems in use, any one of which could be adapted and programmed to implement the invention. Although I have described specific embodiments of the invention, the description is not intended to limit the applicability of the following claims.