Abstract:
A communication system establishes a communication path between users through separate TDM nodes and a packet system. The communication system removes the packet system from the communication path during the communication session. To accomplish the removal, the communication system connects the separate TDM nodes within the TDM system and removes the portion of the communication path that traverses the packet system. If the packet system connects a service node to the communications path, then the communication system effectively removes the service node from the communications path during the session.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is related to the field of communications, and in particular, to the controlled removal of a packet communication system from a communication path during a communication session. 
     2. Description of the Prior Art 
     Time Division Multiplex (TDM) systems have been used for many years to establish communication paths between users. More recently, packet communication systems have also been used to establish communication paths between users. In many cases, the users are connected to separate TDM systems, and the separate TDM systems are connected by a packet communication system. Thus, the communication path between two users extends from the first user through a first TDM system to the packet system, and from the packet system through a second TDM system to the second user. 
     Communication service platforms provide various services to the users, such as operator assistance and voice recognition. To provide the service, a communication path is established from the user to the service platform. In many cases, the service platform then extends the communication path to another user. For example, a first user initiates a communication path to an operator assistance platform, and after providing operator assistance, the platform extends the communication path to a second user. 
     In many scenarios, the service platform is used to establish the communication path between users, but the platform is no longer used after the communication path has been established. For example, the operator assistance platform is used to establish the communication path between users, but the platform is typically not used after this communication path has been established. 
     To free-up the service platform for other users, the portion of the communication path that passes through the service platform is released during the communication session. In TDM systems, a single TDM node extends the communication path from the first user to the service platform, and the same TDM node also extends the communication path from the service platform to the second user. When the service platform is finished providing the service, the platform signals the single TDM node, and the single TDM node eliminates the portion of the communication path to and from the service platform. 
     Unfortunately, the above technique for removing the service node from the communication path is ineffective where a packet network connects separate TDM systems, because the communication path to and from the service node does not pass through the same TDM node. For example, the communication path from a first user extends through a first TDM node and a packet system to a service platform. The communication path then extends from the service platform through the packet system and a second TDM node to a second user. Since the communication path does not pass through the same TDM node both to and from the service platform, neither the first TDM node nor the second TDM node can effectively remove the service platform from the communication path. 
     SUMMARY OF THE INVENTION 
     In a communication system that establishes a communication path between users through separate TDM nodes and a packet system, the communication system removes the packet system from the communication path during the communication session. To accomplish the removal, the communication system connects the separate TDM nodes within the TDM system and removes the portion of the communication path that traverses the packet system. If the packet system connects a service node to the communications path, then the communication system effectively removes the service node from the communications path during the session. 
     In some examples, the user initiates the removal of the packet system from the communication path during the communication session. The user also initiates the addition of the packet system back to the communication path during the session. If the packet system connects a service node to the communication path, the user can effectively remove the service node from the communication path and add the service node back to the communication path during the communication session. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a communication system in an embodiment of the invention. 
         FIG. 2  illustrates the operation of the communication system in an embodiment of the invention to establish a communication path between user systems through TDM nodes and a packet system. 
         FIG. 3  illustrates the operation of the communication system in an embodiment of the invention to remove the packet system from the communication path during the communication session. 
         FIG. 4  illustrates the operation of the communication system in an embodiment of the invention to establish a communication path between user systems through TDM nodes and a packet system. 
         FIG. 5  illustrates the operation of the communication system in an embodiment of the invention to establish a communication path between user systems through TDM nodes and a packet system. 
         FIG. 6  illustrates the operation of the communication system in an embodiment of the invention to remove the packet system from the communication path during the communication session. 
         FIG. 7  illustrate the operation of the communication system in an embodiment of the invention to reset the communication path between the user systems through the TDM nodes and the packet system during the communication session. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  illustrates communication system  100  in an embodiment of the invention. Communication system  100  comprises TDM nodes  103 - 104  and packet system  105 . Packet system  105  includes packet gateways  106 - 107 , service node  108 , and processing system  109 . Communication system  100  exchanges signaling over links  111 - 118 . Communication system  100  exchanges user communications over connections  121 - 128 . Links  111 - 118  and connections  121 - 128  may include various intermediate systems that are omitted for clarity. 
     Processing system  109  is coupled to TDM node  103  by link  113  and to TDM node  104  by link  114 . TDM nodes  103 - 104  are coupled by link  115 . Links  113 - 115  transfer Signaling System #7 (SS7) signaling, Interim Standard 41 (IS-41) signaling, or some other form of TDM network signaling adapted in accord with this disclosure. Processing system  109  is coupled to packet gateway  106  by link  116 , to service node  108  by link  117 , and to packet gateway  107  by link  118 . Links  116 - 118  transfer Session Initiation Protocol (SIP) signaling, Media Gateway Control Protocol (MGCP) signaling, or some other form of packet network signaling adapted in accord with this disclosure. 
     TDM node  103  is coupled to packet gateway  106  by connection  123 . TDM node  104  is coupled to packet gateway  107  by connection  124 . TDM node  103  is coupled to TDM node  104  by connection  125 . Connections  123 - 125  use the TDM format. Packet gateway  106  is coupled to service node  108  by connection  126 . Packet gateway  107  is coupled to service node  108  by connection  127 . Packet gateway  106  is coupled to packet gateway  107  by connection  128 . Connections  126 - 128  use Internet Protocol (IP), Asynchronous Transfer Mode (ATM), Ethernet, or some other packet communication format. 
     User device  101  and TDM node  103  are coupled by link  111  and connection  121 . User device  102  and TDM node  104  are coupled by link  112  and connection  122 . Links  111 - 112  and connections  121 - 122  may use various protocols and may include various intermediate systems. For example, link  111  and connection  121  may include a wireless base station, and link  112  and connection  122  may include a local telephone network. User devices  101 - 102  do not necessarily use the TDM format or TDM network signaling. 
     User devices  101 - 102  comprise telephones, computers, personal digital assistants, Internet appliances, wireless transceivers, or some other user communication device that is adapted in accord with this disclosure. TDM nodes  103 - 104  comprise TDM switches, Mobile Switching Centers (MSCs), wireless transceivers, or some other communication equipment that is adapted in accord with this disclosure. Packet gateways  106 - 107  comprise Voice over Internet Protocol (VOIP) gateways, border controllers, or some other communication device that is adapted in accord with this disclosure. Service node  108  comprises a computer platform that is adapted to exchange user communications to provide a service in accord with this disclosure. The service could include virtual private network, voice recognition, conferencing, operator assistance, voice mail, PIN-based access, location service, or some other communication-based service. Processing system  109  comprises a VOIP soft-switch, media gateway controller, or some other type of communication signaling processor that is adapted in accord with this disclosure. Processing system  109  may be distributed across multiple signaling processors at different locations. 
       FIG. 2  illustrates the operation of communication system  100  in an embodiment of the invention to establish a communications path between user systems  101 - 102  through TDM nodes  103 - 104  and packet system  105 . User device  101  transfers set-up signaling to TDM node  103  to initiate the communication session. TDM node  103  processes the set-up signaling to select TDM connection  123  to packet gateway  106 . TDM node  103  transfers set-up signaling to processing system  109  indicating TDM connection  123 . Processing system  109  processes the set-up signaling to select packet connection  126 . Processing system  109  transfers set-up signaling to packet gateway  106  indicating TDM connection  123  and packet connection  126 . Processing system  109  transfers set-up signaling to service node  108  indicating packet connection  126 . 
     TDM node  102  receives user communications from user device  101  over connection  121 . TDM node  102  transfers the user communications to packet gateway  106  over TDM connection  123 . Packet gateway  106  transfers the user communications to service node  108  over packet connection  126 . Service node  108  processes the user communications to provide a service to user device  101 . For example, service node  108  might provide operator assistance to determine that user device  101  needs to communicate with user device  102 . Service node  108  transfers set-up signaling to processing system  109  in response to providing the service. 
     Processing system  109  processes the set-up signaling from service node  108  to select packet connection  127  and TDM connection  124 . Processing system  109  transfers set-up signaling to service node  108  indicating packet connection  127 . Processing system  109  transfers set-up signaling to packet gateway  107  indicating packet connection  127  and TDM connection  124 . Processing system  109  transfers set-up signaling to TDM node  104  indicating the TDM connection  124 . TDM node  104  processes the set-up signaling from processing system  109  to select connection  122 . TDM node  104  transfers set-up signaling to user device  102 . 
     TDM node  102  receives user communications from user device  101  over connection  121  and transfers the user communications to packet gateway  106  over TDM connection  123 . Packet gateway  106  transfers the user communications to service node  108  over packet connection  126 . Service node  108  transfers the user communications to packet gateway  107  over packet connection  127 . Packet gateway  107  transfers the user communications to TDM node  104  over TDM connection  124 . TDM node  104  transfers the user communications to user device  102  over connection  122 . Thus, user communications for the communication session flow over a communication path from user device  101  to user device  102  through TDM nodes  103 - 104  and packet system  105 . 
       FIG. 3  illustrates the operation of communication system  100  in an embodiment of the invention to remove packet system  105  from the communication path during the communication session. The operation of  FIG. 5  starts after the operations described above for  FIG. 2 . Thus, user communications for the session already flow over the communication path from user device  101  to user device  102  through TDM nodes  103 - 104  and packet system  105 . 
     Service node  108  determines that packet system  105  should be removed from the user communication path for the session. For example, service node  108  may provide operator assistance, verify operational communications between user devices  101 - 102 , and determine that packet system  105  is no longer required. In response to the determination, service node  108  transfers redirect signaling to processing system  109 . 
     Processing system  109  processes the redirect signaling from service node  108  to transfer redirect signaling to TDM node  103 . The redirect signaling to TDM node  103  indicates that TDM connections  123 - 124  should be removed from the communication path for the session and that TDM node  103  should redirect user communications for the session to TDM node  104 . TDM node  103  processes the redirect signaling to select TDM connection  125  for the session. TDM node  103  transfers redirect signaling to TDM node  104  indicating that TDM connection  125  will be used for the session instead of TDM connection  124 . 
     TDM node  103  receives user communications for the session from connection  121  and redirects the user communications to TDM node  104  over TDM connection  125 . TDM node  104  receives the user communications for the session from TDM connection  125  and redirects the user communications to connection  122 . Thus, packet system  105  has been removed from the user communication path during the session. 
     Processing system  109  transfers termination signaling to packet gateway  106  terminating the session over TDM connection  123  and packet connection  126 . Processing system  109  transfers termination signaling to service node  108  terminating the session over packet connections  126 - 127 . Processing system  109  transfers termination signaling to packet gateway  107  terminating the session over packet connection  127  and TDM connection  124 . 
       FIG. 4  illustrates the operation of communication system  100  in an embodiment of the invention to establish a communication path between user systems  101 - 102  through TDM nodes  103 - 104  and packet system  105 .  FIG. 4  shows an alternative technique to that described above for  FIG. 2 . In this alternative technique, processing system  109  completes the communication path through packet system  105  prior to service delivery by service node  108 . 
     User device  101  transfers set-up signaling to TDM node  103  to initiate the communication session. TDM node  103  processes the set-up signaling to select TDM connection  123  to packet gateway  106 . TDM node  103  transfers set-up signaling to processing system  109  indicating TDM connection  123 . 
     Processing system  109  processes the set-up signaling to select packet connections  126 - 127  and TDM connection  124 . Processing system  109  transfers set-up signaling to packet gateway  106  indicating TDM connection  123  and packet connection  126 . Processing system  109  transfers set-up signaling to service node  108  indicating packet connections  126 - 127 . Processing system  109  transfers set-up signaling to packet gateway  107  indicating packet connection  127  and TDM connection  124 . Processing system  109  transfers set-up signaling to TDM node  104  indicating TDM connection  124 . TDM node  104  processes the set-up signaling from processing system  109  to select connection  122 . TDM node  104  transfers set-up signaling to user device  102 . 
     TDM node  102  receives user communications from user device  101  over connection  121  and transfers the user communications to packet gateway  106  over TDM connection  123 . Packet gateway  106  transfers the user communications to service node  108  over packet connection  126 . Service node  108  provides a service to the user communications and transfers the user communications to packet gateway  107  over packet connection  127 . Packet gateway  107  transfers the user communications to TDM node  104  over TDM connection  124 . TDM node  104  transfers the user communications to user device  102  over connection  122 . Thus, user communications for the session flow over the communication path from user device  101  to user device  102  through TDM nodes  103 - 104  and packet system  105 . 
       FIG. 5  illustrates the operation of communication system  100  in an embodiment of the invention to establish a communication path between user systems  101 - 102  through TDM nodes  103 - 104  and packet system  105 .  FIG. 4  shows an alternative technique to those described above for  FIGS. 2 and 4 . In this alternative technique, service node  108  in packet system  105  is not used for the communication session. 
     User device  101  transfers set-up signaling to TDM node  103  to initiate the communication session. TDM node  103  processes the set-up signaling to select TDM connection  123  to packet gateway  106 . TDM node  103  transfers set-up signaling to processing system  109  indicating TDM connection  123 . 
     Processing system  109  processes the set-up signaling to select packet connection  128  and TDM connection  124 . Processing system  109  transfers set-up signaling to packet gateway  106  indicating TDM connection  123  and packet connection  128 . Processing system  109  transfers set-up signaling to packet gateway  107  indicating packet connection  128  and TDM connection  124 . Processing system  109  transfers set-up signaling to TDM node  104  indicating the TDM connection  124 . TDM node  104  processes the set-up signaling from processing system  109  to select connection  122 . TDM node  104  transfers set-up signaling to user device  102 . 
     TDM node  102  receives user communications from user device  101  over connection  121  and transfers the user communications to packet gateway  106  over TDM connection  123 . Packet gateway  106  transfers the user communications to packet gateway  107  over packet connection  128 . Packet gateway  107  transfers the user communications to TDM node  104  over TDM connection  124 . TDM node  104  transfers the user communications to user device  102  over connection  122 . Thus, user communications for the session flow from user device  101  to user device  102  over the communication path through TDM nodes  103 - 104  and packet system  105 . 
       FIG. 6  illustrates the operation of communication system  100  in an embodiment of the invention to remove packet system  105  from the communication path during the communication session.  FIG. 6  shows an alternative to the technique described above for  FIG. 3 . In this alternative technique, the user has the ability to initiate the removal during the session. The operation of  FIG. 6  starts after the operations described above for  FIG. 2 . Thus, user communications for the session already flow from user device  101  to user device  102  over the communication path through TDM nodes  103 - 104  and packet system  105 . 
     Once the session is established, service node  108  transfers a redirect application to user device  101  over connections  126 ,  123 , and  121 . The redirect application may include an icon that is displayed to the user and that may be invoked by the user to initiate redirect. The redirect application enables user device  101  to initiate the removal of packet system  105  from the communication path during the session. Thus, user device  101  controls if and when service node  108  is on the user communication path. 
     Either the user or user device  101  determines that redirection should occur. For example, the user may no longer want service node  108  on the communication path due to cost, quality, or security. In another example, user device  101  may detect poor quality attributable to packet system  105 . There could be other factors that invoke redirection. In response to the determination, user device  101  transfers redirect signaling to service node  108 . The redirect signaling may traverse connections  121 ,  123 , and  126 . 
     Service node  108  processes the redirect signaling from user device  101  to transfer redirect signaling to processing system  109 . The redirect signaling indicates that packet system  105  should be removed from the communication path for the session. Processing system  109  processes the redirect signaling from service node  109  to transfer redirect signaling to TDM node  103 . The redirect signaling indicates that TDM connections  123 - 124  should be removed from the communication path for the session and that TDM node  103  should redirect user communications to TDM node  104 . The redirect signaling also sets TDM node  103  to handle potential reset signaling from user device  101 . TDM node  103  processes the redirect signaling to select TDM connection  125 . TDM node  103  transfers redirect signaling to TDM node  104  indicating that TDM connection  125  will be used for the session instead of TDM connection  124 . 
     TDM node  103  receives user communications for the session from connection  121  and redirects the user communications to TDM node  104  over TDM connection  125 . TDM node  104  receives the user communications from TDM connection  125  and redirects the user communications to connection  122 . Thus, packet system  105  (including service node  108 ) has been removed from the user communication path during the session in response to signaling from user device  101 . 
     Processing system  109  also processes the redirect signaling from service node  108  to transfer suspend signaling as follows. Processing system  109  transfers suspend signaling to packet gateway  106  suspending the session over TDM connection  123  and packet connection  126 . Processing system  109  transfers suspend signaling to service node  108  suspending the session over packet connections  126 - 127 . Processing system  109  transfers suspend signaling to packet gateway  107  suspending the session over packet connection  127  and TDM connection  124 . Alternatively, processing system  109  may not transfer any suspend signaling and leave connections  123 - 124  and  126 - 127  available and unused, or processing system  109  may transfer terminate signaling to release connections  123 - 124  and  126 - 127  from the session. 
       FIG. 7  illustrate the operation of communication system  100  in an embodiment of the invention to reset the communication path between user systems  101 - 102  through TDM nodes  103 - 104  and packet system  105  during the communication session. The operation of  FIG. 7  starts after the operations described above for FIG.  6 . Thus, user communications for the session flow from user device  101  to user device  102  over the communication path through TDM nodes  103 - 104 , but not through packet system  105 . 
     Either the user or user device  101  determines that reset should occur for the communication session. For example, the user may want service node  108  back on the communication path during the session to obtain additional operator assistance, and accordingly, the user would invoke the icon displayed on user device  101 . There could be other factors that invoke reset. In response to the determination, user device  101  transfers reset signaling to TDM node  103 . The reset signaling may be tones or some other user input that traverses connection  121 , or the reset signaling may be a reset message that traverses link  111 . TDM node  103  processes the reset signaling to re-select TDM connection  123  to packet gateway  106 , although a different TDM connection could be used if connection  123  were no longer available. TDM node  103  transfers reset signaling to processing system  109  indicating TDM connection  123  for the session. 
     Processing system  109  processes the reset signaling to select packet connections  126 - 127  and TDM connection  124 , although different connections could be used if these connections were no longer available. Processing system  109  transfers reset signaling to packet gateway  106  indicating TDM connection  123  and packet connection  126 . Processing system  109  transfers reset signaling to service node  108  indicating packet connections  126 - 127 . Processing system  109  transfers reset signaling to packet gateway  107  indicating packet connection  127  and TDM connection  124 . Processing system  109  transfers reset signaling to TDM node  104  indicating TDM connection  124 . 
     TDM node  102  receives user communications from user device  101  over connection  121  and transfers the user communications to packet gateway  106  over TDM connection  123  instead of TDM connection  125 . Packet gateway  106  transfers the user communications to service node  108  over packet connection  126 . Service node  108  provides a service to the user communications and transfers the user communications to packet gateway  107  over packet connection  127 . Packet gateway  107  transfers the user communications to TDM node  104  over TDM connection  124 . TDM node  104  transfers the user communications to user device  102  over connection  122 . Thus, packet system  105  (including service node  108 ) has been added back to the communication path during the session in response to signaling from user device  101 . 
     Note that the redirect and reset signaling may use the same session identifier as the original set-up signaling. Thus, communication system  100  may associate information from the various stages of the communication session. 
     The above description and associated figures teach the best mode of the invention. The following claims specify the scope of the invention. Note that some aspects of the best mode may not fall within the scope of the invention as specified by the claims. Those skilled in the art will appreciate that the features described above can be combined in various ways to form multiple variations of the invention. As a result, the invention is not limited to the specific embodiments described above, but only by the following claims and their equivalents.