Abstract:
A screening and monitoring capability for switch based voice messaging systems that allows a called party to hear the caller and the caller&#39;s voice as the caller leaves a message and break in to start a normal telephone discussion if the caller or the caller&#39;s subject warrants such action. The method and apparatus of this invention provide for an advanced intelligent network service feature that controls the bridging of the connections to the voice mail and the called party&#39;s telephone station. The service feature turns the voice mail off and tears down the connection if the monitoring called party speaks.

Description:
TECHNICAL FIELD 
     The invention relates generally to voice mail, and more particularly to a method and apparatus for screening messages as they are being transmitted for storage in a switch based voice mail system. 
     DESCRIPTION OF THE PRIOR ART 
     As switch based voice mail services have evolved, there is one very advantageous service that customer premises equipment answering machines provide that switch based voice mail has lacked, namely the ability to listen and/or screen a call as a caller stores a message on the storage media. By listening and/or screening an incoming call, the called party has the option of interjecting himself or herself into the call at any time as a message is being stored and talking to the calling party immediately if it concerns a matter upon which the called party wishes to immediately discuss. This is most useful when family, friends or co-workers are traveling and they call from an unfamiliar number, such calls cannot be filtered for special attention by their ICLIDs so if the called party is busy, calls that the called party would typically answer are instead passed to the voice mail system and delayed. 
     A switch based voice mail screening service capability has been specified generically in BellCore Call Screening Capability GR-1512-Core. But an actual embodiment of such a switch based service is not presently available. 
     Thus, there is a long felt need in the art for a switch based method and apparatus for screening voice mail as the voice mail message is transmitted by the calling party to the storage medium. Furthermore, there is a long felt need for switch based method and apparatus for screening voice mail with a capability for interjection by the called party by listening and/or speaking to the calling party instead of leaving the calling party to transmit a message to the switch based voice mail system that will be heard and responded to later. 
     SUMMARY OF THE INVENTION 
     Briefly stated in accordance with one aspect of the invention the aforementioned needs are fulfilled and a technical advance is achieved by providing a voice mail screening service using an advanced intelligent network (AIN) including a service node connected as a bridging point between a calling party, voice mail system, and called subscriber. AIN service switching point (SSP) Service Control Point (SCP) is used to route the calls to the appropriate location for screening as the calling party transmits a message. If the called party is a subscriber to switch based voice mail with screening and interjecting capabilities, the called party screens the call as the calling party transmits information to the switch based voice mail system. Further, the AIN service switching point (SSP) Service Control Point (SCP) is used to change the call characteristics, such as dialed number, calling number and redirecting number to work transparently with existing voice mail systems. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a simplified block diagram illustrating an arrangement for a system for call screening of voice mail. 
     FIG. 2 is a call flow diagram. 
    
    
     DETAILED DESCRIPTION 
     Referring to FIG. 1, an arrangement  10  for a voice mail screening service feature is shown. The arrangement  10  has SSP  100 . SSP  100  is connected to calling party&#39;s station  12  through one or more transit switches  20 , i.e. a public switched telephone network. SSP  100  is connected to called party&#39;s station  14  and via SSP  200  and transit switches  22  to switch based voice mail system (VMS)  500  to which the called party subscribes. 
     SSPs  100 ,  200  and Transit Switches  20 ,  22  are preferrably connected using ISDN User Part (ISUP) Trunks. It is worth noting that SP  100  and SSP  200  may be the same unit, in which case the ISUP trunk shown between SSP  100  and SSP  200  is not necessary and only one link to SS7 network  350 , instead of the two shown in FIG. 1. A service node (SN)  300  is connected to SSP  200  using either a PRI or a BRI interface. VMS  500  is connected to transit switch(es)  22  using as its physical connection a standard voice mail interface such as SMDI, but it could also be another interface such as a PRI or an ISUP interface. 
     In operation, a calling party at station  12  dials the number of called party&#39;s station  14 . The network of transit switches  20  routes this call to the called party&#39;s switching system  10  causing the called party&#39;s station  14  to ring. If the called party does not answer, switching system  10  detects a no answer condition and invokes an existing switch feature, Call Forwarding on No Answer. The call is forwarded to the number of VMS  500 . The number of VMS  500  has been provisioned with an AIN Dialed Number Trigger (DNT) in the switching system  10 . Due to this trigger, an AIN SS7 query (i.e. Info Analyze Message) is made to SCP  400 . This query passes, along with other information as specified in BellCore GR-1298, the calling party line number, the calling party&#39;s number, and the call forwarded number. Based on called party&#39;s number, SCP  400  determines that the called party is a subscriber to voice mail screening service. The SCP  400  returns an Analyze Route Message to the SSP  100  indicating that this call will be routed to Service Node (SN)  300 . The SSP  100  routes the call to SSP  200  of SN  300  and passes call setup information over the D-Channel to the SN  300 . The SN  300  answers the call and stores the calling party&#39;s number, called party&#39;s number and the number of VMS  500 . 
     Next, SN  300  places a call destined for the VMS  500 . In the Setup message of the call to VMS  500  SN  300  specifies the calling party with the number of the calling party&#39;s station  12 , the original called party with the number of the called party&#39;s station  14 , and the called party with the number of the VMS  500 . SSP  200  routes this call to VMS  500 , which in the example of FIG. 1 crosses transit switches  22 , to VMS  500 . Then, SN  300  bridges the call from the calling party at station  12  with the call to the VMS  500 . The VMS  500  plays the subscriber greeting and begins collecting the message from the calling party. 
     The called party, who is a subscriber to the voice mail message screening service feature, if he or she desires to listen to the calling party leaving a message, goes off hook and dials a string, such as *xx, yyyxxxx, etc. This string has been provisioned with a trigger (Public Office Dialing Plan Trigger or DNT based on the format of the number) in the SSP  100 . This causes an AIN SS7 query (InfoAnalyze Message) to be transmitted to the SCP  400 . The SCP  400  returns the number of the SN  300  as the routing number in an Analyze Info Message response to the query. The SSPs  100 ,  200  route the call to the SN  300 . The SN  300  answers the call, correlates the called party&#39;s number with the previous call between the calling party at station  12  and the VMS  500 . Next, the SN  300  bridges the called party on to the call between the calling party at station  12  and the voice mail system  500 . While the calls are bridged, the SN  300  monitors the called party&#39;s leg of the call for spoken word. If the called party speaks, the SN  300  detects it and drops the connection to the voice mail system  500 . Next, the SN  300  signals to the SSP  200  to bridge the call in the switch using a switch capability like the 2 B-Channel Transfer Feature. 
     If, on the other hand, the called party at station  14  chooses not to screen the call, SN  300  detects when the calling party at station  12  or VMS  500  terminates their leg of the call and tears down the other leg of the call. This ends the call initiated by the calling party at station  12 . 
     Variations 
     In another embodiment of the invention, the number used for call forwarding is the service node number instead of the voice mail number. In such a case, the information delivered to SN  300  does not include the number of the voice mail system, therefore the following steps are taken when SN  300  places the call destined for the voice mail system  500 : The SN  300  places a call the call for the voice mail leg. A trigger in the SSP  200  such as a B-Channel Setup causes an AIN SS7 Info Collected Message to be sent to SCP  400 . Based on the calling party ID parameter which contains the called party&#39;s (subscriber&#39;s) number, SCP  400  determines the VMS  500  number and returns an Analyze Information response that includes routing information to the VMS  500 . 
     In yet another embodiment of the invention, after the called party subscriber at station  14  has decided to take the call, SN  300  and VMS  500  can communicate using a protocol such as OCL to remove from VMS  500  any partial message left by the calling party. 
     In yet another embodiment, after the calling party at station  12  has started to leave a message on VMS  500 , SN  300  can place a call to the called party subscriber at station  14  with a special ringing pattern, e.g. a “ping ring”, to indicate that the transmission of a message to VMS  500  is in progress. In such a case if the called party subscriber at station  14  lifts the handset off-hook, then SN  300  directly bridges the called party subscriber at station  14  into the call in screening mode. 
     In yet another embodiment, SCP  400  determines whether the calling party has finished leaving a message by the use of a Termination message when routing the call to SN  300 . If the called party subscriber at station  14  attempts to screen a call to voice mail that has already been completed then the calling party subscriber at station  14  is routed to an announcement indicating the completion of the previous call. 
     In yet another embodiment of the invention, SCP  400  has the capability to route to multiple service nodes, i.e. SN  300  and others (not shown). SCP  400  maintains state on which SN the call from the calling party is routed to and routes the screening call from the called party subscriber to the proper SN. 
     Thus, it will now be understood that there has been described a new method and apparatus for screening a call as it is transmitted to a switch based voice mail system with the option of the called party to cease screening and begin conversing with the calling party of the call. While the invention has been particularly illustrated and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form, details, and applications may be made therein. It is accordingly intended that the appended claims shall cover all such changes in form, details and applications which do not depart from the true spirit and scope of the invention.