Abstract:
A method for restricting the completion of a call made to a subscriber is disclosed. The method includes activating a termination attempt trigger, requesting call-processing instructions in response to detection of the activated termination attempt trigger, receiving call-processing instructions, and redirecting the call responsive to the call-processing instructions.

Description:
BACKGROUND 
   The present application is related, generally, to systems and methods for restricting incoming calls. For a variety of reasons, there are times when a telephone customer may not want to be disturbed by the ringing that announces an incoming telephone call. To prevent the receipt of such calls, customers have resorted to unplugging the jack, leaving the telephone off-hook, turning off the ringer, or subscribing to a call forwarding service. Although such remedies can be effective in stopping the telephone from ringing, each remedy has shortcomings associated therewith. 
   Unplugging the jack from a telephone disconnects the telephone from the telephone system. During the time the telephone is disconnected, no outgoing calls can be placed from the telephone, and no incoming calls can be received at the telephone. Leaving the telephone off-hook allows for the placement of outgoing calls but prevents the receipt of any incoming calls, including calls that the customer may have wanted to receive. In addition, leaving the telephone off-hook typically results in the generation of a beeping sound, a sound some customers consider to be more annoying than the ringing that announces an incoming telephone call. Call forwarding services allow for the placement of outgoing calls and can automatically redirect all incoming calls, even calls the customer may have wanted to receive, to the customer&#39;s voice mailbox. Although a calling party can leave a voice message for the customer, the customer does not know who called or why they called until the message is retrieved. 
   SUMMARY 
   In one general respect, the present invention is directed to a system for restricting incoming calls. According to one embodiment, the system includes a service switching point connected to a subscriber line having a termination attempt trigger provisioned thereto, a service control point in communication with the service switching point, and an intelligent peripheral in communication with the service switching point. The service control point is for executing a call restriction Service Program Application (SPA), and the intelligent peripheral is for executing a call restriction override SPA. 
   In another general respect, the present invention is directed to a method for restricting incoming calls. According to one embodiment, the method includes activating a termination attempt trigger, requesting call-processing instructions in response to detection of the activated termination attempt trigger, receiving the call-processing instructions, and redirecting the call responsive to the call-processing instructions. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  illustrates one embodiment of a call restriction system; 
       FIG. 2  illustrates another embodiment of the call restriction system; 
       FIGS. 3A–3C  illustrate one embodiment of a process flow of the call restriction system of  FIG. 1 ; and 
       FIGS. 4A–4C  illustrate one embodiment of a process flow of the call restriction system of  FIG. 2 . 
   

   DESCRIPTION 
   It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for purposes of clarity, other elements. Those of ordinary skill in the art will recognize, however, that these and other elements may be desirable. However, because such elements are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements is not provided herein. 
   According to one embodiment, the present invention utilizes the intelligent functionality of an Advanced Intelligent Network (AIN). The AIN is a network used in conjunction with a conventional telephone network, such as the public switched telephone network (PSTN), to provide enhanced voice and data services and dynamic routing capabilities using two different networks. The actual voice call is transmitted over a circuit-switched network, but the signaling is done on a separate packet-switched network. The functioning of an AIN is disclosed in U.S. Pat. No. 5,438,568, which is incorporated herein by reference. 
     FIG. 1  illustrates one embodiment of a call restriction system  10 . The call restriction system  10  may be utilized in conjunction with a telephone network such as, for example, the Public Switched Telephone Network (PSTN), to restrict the completion of incoming calls to a subscriber of a call restriction service. The call restriction system  10  may include Service Switching Points (SSPs)  12 , a Signal Transfer Point (STP) 14 , a Signal Control Point (SCP)  16 , a database  18 , and an Intelligent Peripheral (IP)  20 . 
   The SSP  12   a  may be a central office switch used to interconnect customer premises equipment (i.e., terminal equipment such as telephones, modems, or answering machines that are connected to the telephone network and reside on the customers&#39; premises). The SSP  12   a  may have a plurality of subscriber lines  22  connected thereto. The subscriber lines  22  may be, for example, local loops comprising conventional twisted pair loop circuits connected between the SSP  12   a  and the customer premises equipment. Each subscriber line  22  connected to the SSP  12   a  may also be connected to a terminating piece of customer premises equipment such as, for example, a landline telephone  24 . Alternatively, the terminating equipment may be any other type of communications unit such as, for example, a telecopier, a personal computer, a modem, an answering machine, or a private branch exchange (PBX) switching system. 
   A subscriber line  22  may be connected to the SSP  12   a  and have a termination attempt trigger  26  provisioned thereto. The termination attempt trigger  26  may be provisioned to the subscriber line  22  such that any call placed to that subscriber line  22  would activate the termination attempt trigger  26 . When the SSP  12   a  recognizes or detects that the termination attempt trigger  26  has been activated by an incoming call, the SSP  12   a  may suspend normal call processing, then query the SCP  16  for instructions as to how to process the call. 
   The SSP  12   b  may be a host SSP connected to the IP  20  as described in more detail hereinbelow. The SSP  12   b  may be similar to the SSP  12   a , and may be connected to the SSP  12   a  via communication link  28 , which may be, for example, one or more trunk circuits, such as T-1 trunk circuits. According to one embodiment, the call restriction system  10  may include a plurality of SSPs. For example, any number of SSPs similar to the SSP  12   a  may be connected between the SSP  12   a  and the SSP  12   b , and may be connected to one another via communication link  28 . 
   The STP  14  is a packet switch that routes signaling and control messages between the SSPs  12  and the SCP  16 . As illustrated in  FIG. 1 , the STP  14  is in communication with the SSPs  12  via communication link  30  and with the SCP  16  via communication link  32 . Communication links  30 ,  32  employ out-of-band signaling using, for example, the Signaling System 7 (SS7) signaling protocol. 
   The SCP  16  is a server associated with a database  18 , and may provide instructions to the SSPs  12  as requested and required. The SCP  16  may be an intelligent database server such as, for example, an Intelligent Network Service Control Point available from Lucent Technologies Inc., Murray Hill, N.J. The intelligent functionality of the SCP  16  may be realized by application programs, such as programmable Service Program Applications (SPA), which are executed by the SCP  16 . According to one embodiment, the SCP  16  may execute a call restriction SPA associated with the call restriction service of the present invention that may be enabled or disabled by a subscriber to the call restriction service. According to one embodiment, the subscriber may turn the call restriction service on and off via a touch-tone telephone. For example, the subscriber may call a special telephone number to toggle the call restriction service on or off. 
   The database  18  may be for storing customer information used in providing enhanced calling services, such as the call restriction service provided by the call restriction system  10 . According to one embodiment, the database  18  may be in communication with the SCP  16  via communication link  34 , which may be, for example, a portion of a communication network such as, for example, a Local Area Network (LAN), a Metropolitan Area Network (MAN), or a Wide Area Network (WAN). According to another embodiment, the database  18  may reside at the SCP  16 . Although the call restriction system  10  illustrated in  FIG. 1  only shows one database  18  associated with the SCP  16 , it is understood that more than one database  18  may be associated with the SCP  16 . 
   The IP  20  may provide an enhanced feature or service that requires an audio connection between the IP  20  and customer premises equipment connected to a subscriber line  22 . The IP  20  may be any type of AIN-compliant service node, and may be, for example, a Compact Services Node (CSN) available from Lucent Technologies Inc., Murray Hill, N.J. According to one embodiment, the IP  20  may be associated with one or more databases (not shown). Similar to the SCP  16 , the intelligent functionality of the IP  20  may be realized by programmable SPAs executable by the IP  20 . According to one embodiment, the IP  20  may execute a call restriction override SPA associated with the call restriction service. 
   As illustrated in  FIG. 1 , the IP  20  is in communication with the SSP  12   b  via communication link  36 . Communication link  36  may be, for example, an Integrated Service Digital Network (ISDN) Primary Rate Interface (PRI), an ISDN Basic Rate Interface (BRI), or a T-1 trunk circuit. 
   Although the call restriction system  10  illustrated in  FIG. 1  includes only two SSPs  12 , one STP  14 , one SCP  16 , one database  18 , and one IP  20 , it is understood that the call restriction system  10  may further include an additional number of these components as well as other network components that are not included in  FIG. 1  for purposes of clarity. For example, the call restriction system  10  may additionally include redundant STPs and SCPs to take over if the STP  14  or the SCP  16  should fail. Further, the call restriction system  10  may include regional STPs and regional SCPs in communication with, for example, the local STP  14 , for routing and servicing calls between different Local Exchange Carriers (LECs). 
     FIG. 2  illustrates another embodiment of the call restriction system  10 . The call restriction system  20  is similar to the call restriction system  10  of  FIG. 1 , but also includes a communication link  38  connected between the SCP  16  and the IP  20 . Therefore, according to this embodiment, the SCP  16  may communicate directly with the IP  20 , and may provide instructions to the IP  20  as requested and required. The communication link  38  may be, for example, a portion of a communication network such as, for example, a Local Area Network (LAN), a Metropolitan Area Network (MAN), or a Wide Area Network (WAN). 
     FIGS. 3A–3C  illustrate one embodiment of the process flow of the call restriction system  10  of  FIG. 1 . According to this embodiment, when a customer first subscribes to a call restriction service, certain information must be provisioned before the call restriction service can become fully operational for the subscriber. Such information may be provisioned at the SCP  16  and may include, for example, the name of the customer, the customer&#39;s landline telephone number, a telephone number that the customer wishes to have incoming calls redirected to while the call restriction service is enabled, and exempt telephone numbers that the customer wishes to have calls originating therefrom automatically bypass the call restriction service. The customer may designate any number of such exempt telephone numbers. Provisioned information may also include, for example, one or more service override codes for bypassing the call restriction service. A system administrator may provision the call restriction service by entering the information via a Service Management System (SMS) that is in communication with the call restriction system  10 . The information may be modified at any time and as often as the customer desires. Alternatively, the customer may provision the call restriction service remotely via the Internet by providing information to a web server (not shown), which in turn passes the information to the SMS for provisioning of the call restriction service. For the call restriction system  10  of  FIG. 2 , the information may be provisioned to the IP  20  via the SCP  16  and communication link  38 . Once the necessary information has been provisioned, the subscriber may activate the call restriction service. 
   The process begins at block  40 , where a calling party places a call to the customer&#39;s landline telephone  24 . The call may be placed, for example, from a landline telephone or a mobile telephone. From block  40 , the process proceeds to block  42 , where the call is received at the SSP  12   a  connected to the subscriber line  22 , which is connected to the customer&#39;s landline telephone  24 . From block  42 , the process proceeds to block  44 , where the incoming call activates the termination attempt trigger  26  provisioned to the subscriber line  22  connected to the customer&#39;s landline telephone  24 . From block  44 , the process proceeds to block  46 , where the SSP  12   a  detects or recognizes that the termination attempt trigger  26  has been activated. From block  46 , the process proceeds to block  48 , where the SSP  12   a  suspends normal call processing, and generates a query message for call-processing instructions. Such generation may include, for example, assembling an information-collected message that comprises a portion of the query message. 
   From block  48 , the process proceeds to block  50 , where the SSP  12   a  transmits the query message to the SCP  16  via the STP  14 . The query message may be transmitted via-out-of-band signaling using the SS7 signaling protocol. From block  50 , the process proceeds to block  52 , where the SCP  16  receives the query message transmitted from the SSP  12   a.    
   From block  52 , the process proceeds to block  54 , where the SCP  16  determines whether the call restriction service is turned on or off. The SCP  16  may determine whether the call restriction service is turned on or off by checking a flag indicative of whether the call restriction SPA associated with the call restriction service is enabled or disabled. From block  54 , the process may proceed to block  56 , or to block  62 . 
   If the call restriction service is turned off, the process proceeds from block  54  to block  56 , where the SCP  16  generates a message in response to the query message and transmits the response message to the SSP  12   a  via the STP  14 . The response message may be an analyze route message and may include, for example, an instruction to process the call in the normal manner. From block  56 , the process proceeds to block  58 , where the SSP  12   a  receives the response message transmitted from the SCP  16 . From block  58 , the process proceeds to block  60 , where the SSP  12   a  connects the calling party to the customer&#39;s landline telephone  24  via the subscriber line  22 . 
   If the call restriction service is turned on, the process proceeds from block  54  to block  62 , where the SCP  16  determines whether the calling party&#39;s telephone number is an exempt telephone number. The SCP  16  may determine whether the calling party&#39;s telephone number is an exempt telephone number by comparing the calling party&#39;s telephone number to a list of exempt telephone numbers populated in the database  18 . From block  62 , the process may proceed to block  56 , or to block  64 . 
   If the calling party&#39;s telephone number is an exempt telephone number, the process proceeds from block  62  to block  56 , where the process proceeds as described hereinabove. If the calling party&#39;s telephone number is not an exempt telephone number, the process proceeds from block  62  to block  64 , where the SCP  16  generates a message in response to the query message and transmits the response message to the SSP  12   a  via the STP  14 . The response message may be an analyze route message and may include, for example, an instruction to redirect the call to the IP  20 . From block  64 , the process proceeds to block  66 , where the SSP  12   a  receives the response message and redirects the call to the IP  20 . The SSP  12   a  may redirect the call to the IP  20  by redirecting the call to the host SSP  12   b  via communication link  28 , which in turn passes the call to the IP  20  via communication link  36 . According to one embodiment, the call may pass thru any number of SSPs between the SSP  12   a  and the host SSP  12   b . According to another embodiment, the subscriber line  22  connected to the customer&#39;s landline telephone  24  may be connected to the host SSP  12   b  that is in communication with the IP  20  via communication link  36 . For this embodiment, the SSP  12   b  is the SSP that sends the query message to the SCP  16 , receives the response message from the SCP  16 , and redirects the call directly to the IP  20  via communication link  36 . 
   From block  66 , the process proceeds to block  68 , where the IP  20  takes control of the call and plays an announcement to the calling party. The announcement may inform the calling party that the customer does not wish to receive any incoming telephone calls at that time. The announcement may also give the calling party the option of entering a service override code to connect the calling party to the customer&#39;s landline telephone  24 , or the option of leaving a voice message for the customer. For example, according to one embodiment, the announcement may instruct the calling party to enter a service override code to connect to the customer, or to press the numeral “1” to leave a voice message for the customer. The calling party may enter the service override code by pressing a combination of the buttons of a touch-tone telephone. According to another embodiment, the announcement may prompt the calling party to verbalize the service override code to connect to the customer, or to speak the word “one” to leave a voice message for the customer. From block  68 , the process proceeds to block  70 , where the IP  20  determines whether the calling party has responded to the announcement by entering the service override code or indicating the desire to leave a voice message. According to one embodiment, the call may be ended if the caller does not respond to the announcement. 
   From block  70 , the process may proceed to block  72 , or to block  74 . If the calling party has indicated a desire to leave a voice message, the process proceeds from block  70  to block  72 , where the IP  20  may gather the information indicating a desire to leave a voice message, then connect the calling party to the customer&#39;s voice mailbox via the host SSP  12   b . If the calling party has entered a service override code, the process proceeds from block  70  to block  74 , where the IP  20  may capture the entered service override code and redirect the call to the SSP  12   a  via the host SSP  12   b . From block  74 , the process proceeds to block  76 , where the termination attempt trigger  26  provisioned to the SSP  12   a  is activated in response to receipt of the call redirected from the IP  20  via the host SSP  12   b . From block  76 , the process proceeds to block  78 , where the SSP  12   a  detects or recognizes the activated trigger. From block  78 , the process proceeds to block  80 , where the SSP  12   a  suspends normal call processing, and generates a query message for call-processing instructions. From block  80 , the process proceeds to block  82 , where the SSP  12   a  transmits the query message to the SCP  16  via the STP  14 . 
   From block  82 , the process proceeds to block  84 , where the SCP  16  receives the query message transmitted from the SSP  12   a . From block  84 , the process proceeds to block  86 , where the SCP  16  recognizes that the query was generated in response to a call redirected from the IP  20 , and the SCP  16  determines whether the service override code entered by the calling party is a valid service override code. The SCP  16  may determine whether the service override code entered by the calling party is a valid service override code by comparing the service override code entered by the calling party to a list of valid service override codes populated in the database  18 . 
   From block  86 , the process may proceed to block  88 , or to block  90 . If the SCP  16  determines that the service override code entered by the calling party is a valid service override code, the process proceeds from block  86  to block  88 , where the SCP  16  generates a response message instructing the SSP  12   a  to connect the call to the subscriber line connected to the customer&#39;s landline telephone  24 , and transmits the response message to the SSP  12   a  via the STP  14 . From block  88 , the process proceeds to block  58 , where the process proceeds as described hereinbefore. 
   If the SCP  16  determines that the service override code entered by the calling party is not a valid service override code, the process proceeds from block  86  to block  90 , where the SCP  16  generates a response message instructing the SSP  12   a  to end the call, and transmits the response message to the SSP  12   a  via the STP  14 . From block  90 , the process proceeds to block  92 , where response message is received by the SSP  12   a , and the call is ended. 
     FIGS. 4A–4C  illustrate a process flow of one embodiment of the call restriction system  10  of  FIG. 2 . The process flow is identical to the process flow described hereinabove with respect to  FIGS. 3A–3C  for blocks  40 – 70 . Thus, this process flow will only be described from block  70  forward. 
   From block  70 , the process may proceed to block  94 , where the IP  20  determines whether the service override code entered by the calling party is a valid service override code. The IP  20  may determine whether the service override code entered by the calling party is a valid service override code by requesting the SCP  16  to compare the service override code entered by the calling party to a list of valid service override codes populated in the database  18 . The IP  20  may send the request to the SCP  16  via the communication link  38 , and the SCP  16  may inform the IP  20  of its determination via communication link  38 . According to another embodiment, the IP  20  may determine whether the service override code input by the calling party is a valid service override code by comparing the service override code input by the calling party to a list of valid service override codes populated in a database associated with the IP  20 . 
   From block  94 , the process may proceed to block  96 , or back to block  68 . If the service override code input by the calling party is not a valid service override code, the process proceeds from block  94  back to block  68 , where the process proceeds as described hereinabove. According to one embodiment, if a predetermined number of invalid service override codes have been input by the calling party, the call may be disconnected. If the service override code input by the calling party is a valid service override code, the process proceeds from block  94  to block  96 , where the call is redirected from the IP  20  to the SSP  12   a  via the host SSP  12   b . From block  96 , the process proceeds to block  98 , where the termination attempt trigger  26  provisioned to the SSP  12   a  is activated in response to receipt of the call redirected from the IP  20  via the host SSP  12   b . From block  98 , the process proceeds to block  100 , where the SSP  12   a  detects or recognizes the activated trigger. From block  100 , the process proceeds to block  102 , where the SSP  12   a  suspends normal call processing. From block  102 , the process proceeds to block  104 , where the SSP  12   a  generates a query message for call-processing instructions, and transmits the query message to the SCP  16  via the STP  14 . 
   From block  104 , the process proceeds to block  106 , where the SCP  16  receives the query message transmitted from the SSP  12   a , and recognizes that the query was generated in response to a call redirected from the IP  20 . From block  106 , the process proceed to block  108 , where the SCP  16  generates a response message instructing the SSP  12   a  to connect the call to the subscriber line connected to the customer&#39;s landline telephone  24 , and transmits the response message to the SSP  12   a  via the STP  14 . From block  108 , the process proceedS to block  58 , where the process proceeds as described herinbefore. 
   While several embodiments of the invention have been described, it should be apparent, however, that various modifications, alterations and adaptations to those embodiments may occur to persons skilled in the art with the attainment of some or all of the advantages of the present invention. For example, the systems and methods described hereinabove may also be adapted to restrict incoming calls to wireless telephones. It is therefore intended to cover all such modifications, alterations and adaptations without departing from the scope and spirit of the present invention as defined by the appended claims.