PATENT DOCUMENT

Publication Number: US-8619637-B2
Application Number: US-201213525673-A
Country: US
Kind Code: B2

Title: Multiple-termination routing in a wireless network environment with an internet protocol core

Abstract:
Methods for multiple-termination routing in a wireless network environment that includes an Internet Protocol (“IP”) core are described herein. One method includes receiving a call delivery request. The call delivery request includes a called number. The call features associated with the called number are determined. A determination is made whether the call features include multiple-termination routing information for a plurality of potential terminating devices. When the call features include the multiple-termination routing information including at least one termination to be routed utilizing Session Initiation Protocol (“SIP”), a call setup is initiated to each of the plurality of potential terminating devices.

Claims:
What is claimed is: 
     
       1. A method for multiple-termination routing in a wireless network environment, the method comprising:
 receiving a call delivery request, wherein the call delivery request includes a called number; 
 determining call features associated with the called number; 
 determining whether the call features include multiple-termination routing information to a plurality of potential terminating devices; 
 when the call features include multiple-termination routing information including at least one termination to be routed utilizing Session Initiation Protocol (“SIP”), initiating a call setup to each of the plurality of potential terminating devices; and 
 when the potential terminating device is a public switched telephone network (“PSTN”)-protocol based device, sustaining signaling communication with a media gateway for enabling the PSTN-protocol based device to interwork with an Internet Protocol (“IP”) core while initiating the call setup to each of the plurality of potential terminating devices. 
 
     
     
       2. The method of  claim 1 , further comprising:
 when the call delivery request is a SIP INVITE, responding to the received call delivery request with a ringback message, wherein the ringback message instructs the sender of the call delivery request to generate ringback to the calling party terminating device. 
 
     
     
       3. The method of  claim 1 , wherein said initiating a call setup to each of the plurality of potential terminating devices comprises:
 consecutively initiating the call setup to each of the plurality of potential terminating devices; 
 extending a call setup leg to the consecutively initiated call setups in response to a received provisional response, wherein the received provisional response provides call connection information to be used for establishing a bearer path; and 
 upon detecting a first potential terminating device to complete the call setup, foregoing initiation of the subsequent call setup to any of the remaining potential terminating devices. 
 
     
     
       4. The method of  claim 1 , wherein said initiating the call setup to each of the plurality of potential terminating devices comprises:
 concurrently initiating the call setup to each of the plurality of potential terminating devices; 
 extending a call setup leg to each of the concurrently initiated call setups in response to a received provisional response, wherein the received provisional response provides call connection information that is to be used for establishing a bearer path; and 
 upon detecting a first potential terminating device to complete the call setup, releasing the call setup to any of the remaining potential terminating devices. 
 
     
     
       5. The method of  claim 1 , wherein the multiple-termination routing information comprises:
 a member list providing the plurality of potential terminating devices; and 
 information indicating when to request instructions on call processing relating to a device of the plurality of potential terminating devices. 
 
     
     
       6. The method of  claim 1 , further comprising:
 providing timing information as to when to invoke error treatment for a plurality of bearers for the call setup. 
 
     
     
       7. A switching center, comprising:
 one or more processors; and 
 one or more memory mediums coupled to the one or more processors, wherein the one or more memory mediums store program instructions that are executable by the one or more processors to:
 receive a call delivery request, wherein the call delivery request includes a called number; 
 determine call features associated with the called number; 
 determine whether the call features include multiple-termination routing information to a plurality of potential terminating devices; 
 
 when the call features include multiple-termination routing information including 
 at least one termination to be routed utilizing Session Initiation Protocol (“SIP”), initiate a call setup to each of the plurality of potential terminating devices; and 
 when the potential terminating device is a public switched telephone network (“PSTN”)-protocol based device, sustain signaling communication with a media gateway for enabling the PSTN-protocol based device to interwork with an Internet Protocol (“IP”) core while initiating the call setup to each of the plurality of potential terminating devices. 
 
     
     
       8. The switching center of  claim 7 , wherein the program instructions are further executable to:
 when the call delivery request is a SIP INVITE, respond to the received call delivery request with a ringback message that instructs the sender of the call delivery request to generate ringback to the calling party terminating device. 
 
     
     
       9. The switching center of  claim 7 , wherein the program instructions are further executable to:
 consecutively initiate the call setup to each of the plurality of potential terminating devices; 
 extend a call setup leg to the consecutively initiated call setups in response to a received provisional response, wherein the received provisional response provides call connection information to be used for establishing a bearer path; and 
 upon detecting a first potential terminating device to complete the call setup, foregoing initiation of a subsequent call setup to the remaining potential terminating devices. 
 
     
     
       10. The switching center of  claim 7 , wherein the program instructions are further executable to:
 concurrently initiate the call setup to each of the plurality of potential terminating devices; 
 extend a call setup leg to each of the concurrently initiated call setups in response to a received provisional response, wherein the received provisional response provides call connection information that is to be used for establishing a bearer path; and 
 upon detecting a first potential terminating device to complete the call setup, release the call setup to any of the remaining potential terminating devices. 
 
     
     
       11. The switching center of  claim 7 , wherein the multiple-termination routing information comprises:
 a member list providing the plurality of potential terminating devices; and 
 information indicating when to request instructions on call processing relating to a device of the plurality of potential terminating devices. 
 
     
     
       12. A non-transitory, computer accessible memory medium storing program instructions for multiple-termination routing in an wireless network, wherein the program instructions are executable by a processor to:
 receive a call delivery request, wherein the call delivery request includes a called number; 
 determine call features associated with the called number; 
 determine whether the call features include multiple-termination routing information to a plurality of potential terminating devices; 
 when the call features include multiple-termination routing information including at least one termination to be routed utilizing Session Initiation Protocol (“SIP”), initiate a call setup to each of the plurality of potential terminating devices; and 
 when the potential terminating device is a public switched telephone network (“PSTN”)-protocol based device, sustain signaling communication with a media gateway for enabling the PSTN-protocol based device to interwork with an Internet Protocol (“IP”) core while initiating the call setup to each of the plurality of potential terminating devices. 
 
     
     
       13. The non-transitory, computer accessible memory medium of  claim 12 , wherein the program instructions are further executable to:
 when the call delivery request is a SIP INVITE, respond to the received call delivery request with a ringback message, wherein the ringback message instructs the sender of the call delivery request to generate ringback to the calling party terminating device. 
 
     
     
       14. The non-transitory, computer accessible memory medium of  claim 12 , wherein said initiating a call setup to each of the plurality of potential terminating devices comprises:
 consecutively initiating the call setup to each of the plurality of potential terminating devices; 
 extending a call setup leg to the consecutively initiated call setups in response to a received provisional response, wherein the received provisional response provides call connection information to be used for establishing a bearer path; and 
 upon detecting a first potential terminating device to complete the call setup, foregoing initiation of the subsequent call setup to any of the remaining potential terminating devices. 
 
     
     
       15. The non-transitory, computer accessible memory medium of  claim 12 , wherein said initiating the call setup to each of the plurality of potential terminating devices comprises:
 concurrently initiating the call setup to each of the plurality of potential terminating devices; 
 extending a call setup leg to each of the concurrently initiated call setups in response to a received provisional response, wherein the received provisional response provides call connection information that is to be used for establishing a bearer path; and 
 upon detecting a first potential terminating device to complete the call setup, releasing the call setup to any of the remaining potential terminating devices. 
 
     
     
       16. The non-transitory, computer accessible memory medium of  claim 12 , wherein the multiple-termination routing information comprises:
 a member list providing the plurality of potential terminating devices; and 
 information indicating when to request instructions on call processing relating to a device of the plurality of potential terminating devices. 
 
     
     
       17. The non-transitory, computer accessible memory medium of  claim 12 , wherein the program instructions are further executable to:
 provide timing information as to when to invoke error treatment for a plurality of bearers for the call setup.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This invention is a continuation application of U.S. patent application Ser. No. 11/352,757, entitled “Multiple-Termination Routing in a Wireless Network Environment with an Internet Protocol Core”, filed Feb. 13, 2006 now U.S. Pat. No. 8,208,413, which claims priority pursuant to 35 U.S.C. §119 (e) to U.S. Provisional Application Ser. No. 60/652,561, filed Feb. 14, 2005, and to U.S. Provisional Application Ser. No. 60/661,163, filed Mar. 11, 2005. U.S. patent application Ser. No. 11/352,757, U.S. Provisional Application Ser. No. 60/652,561, and U.S. Provisional Application Ser. No. 60/661,163 are all hereby incorporated by reference in their entirety as though fully and completely set forth herein. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present invention relates generally to cellular wireless communication networks; and more particularly to mobile station operation in a legacy mobile station domain communication network. 
     2. Related Art 
     Cellular wireless networks include a “network infrastructure” that facilitates wireless communications with mobile terminals operating within a particular service coverage area. The network infrastructure couples to other network elements to support numerous types of communications, for example, the Public Switched Telephone Network (PSTN), the Internet, et cetera. The network infrastructure may route communications to other subscribing wireless units, to terminals coupled to the PSTN, to terminals coupled to the Internet, or to terminals coupled via another network to one of these networks. 
     Various wireless interface specifications have been developed to standardize wireless communications between the mobile terminals and the network infrastructure and between components that comprise the network infrastructure. Wireless interface specifications include, for example, the Advanced Mobile Phone Service (AMPS) specifications, the Global System for Mobile communications (GSM) specifications, the Code Division Multiple Access (CDMA) specifications, and the Time Division Multiple Access (TDMA) specifications. Generations of these specifications are generally referred to as first generation (1G), second generation (2G), third generation (3G), fourth generation (4G), et cetera. Each advancing generation of standards typically performs and/or supports a greater number of services, a greater number of features, and provides better communication qualities. These operating specifications may also be partially deployed from generation to generation, for example, 2G to 2.5G. 
     Some partial generation wireless specification updates may be deployed using a legacy infrastructure. For example, a 2.5G network has been deployed using upgraded components of a 2G network. When moving from one generation to another generation, however, the network infrastructure must typically be rebuilt using new infrastructure components. 
     Network infrastructure replacement is both expensive and difficult to deploy. An additional problem resulting from the generational replacement relates to backward compatibility of subscriber services. With 3G networks, for example, a subscriber subscribes to 3G services, which includes a suite of services. A 3G subscription may include, for example, circuit switched voice services for the subscriber&#39;s 2G mobile terminal, packet switched voice service for the subscriber&#39;s 3G packet switched mobile terminal, packet data services for the subscriber&#39;s personal data assistant, and packet data services for the subscriber&#39;s notebook computer, among other services. Each of the subscriber&#39;s wireless devices, however, may not be compatible with the 3G infrastructures. 
     In a typical next generation 3G infrastructure, legacy terminal support will be provided. When 3G systems are deployed, 3G mobile terminals will be placed into service. In such cases, the 3G infrastructures will support the 3G services for the 3G mobile terminals as they operate within the respective service areas. The 3G mobile terminals, however, must also be serviced while roaming into legacy 2G wireless networks. Thus backward compatibility issues arise that have not heretofore been addressed. 
     Further, 3G wireless terminals may be placed in service within a legacy network, and thus will be limited in their operation to certain services. If such a 3G wireless device roams from its home service area (that is, the area for which the subscriber normally obtains service) into a visiting service area that supports all 3G packet switched services, the 3G wireless device should not be allowed to receive services to which it does not subscribe. In such case, the visited network must prevent delivery of these services. 
     Thus, there is a need in the art for a system and method that may be employed to support services for both legacy mobile terminals and next generation mobile terminals operating within a next generation wireless communication systems and further to support services for next generation terminals operating within next generation networks for which the subscriber has subscribed to legacy networks based services. 
     SUMMARY 
     Provided is multiple-termination routing in a wireless network environment that includes an Internet Protocol (“IP”) core, where a call delivery request is received. The call delivery request is based upon intelligent network protocols and includes a called number. The call features associated with the called number are retrieved, and a determination is made whether the call features include multiple-termination routing information for a plurality of potential terminating devices. When the call features include multiple-termination routing information wherein at least one termination to be routed utilizes Session Initiation Protocol (“SIP”), independent call setups are initiated, concurrently or consecutively, to each of the plurality of potential terminating devices. 
     In a further aspect, when the call delivery request is a SIP INVITE, responding to the received call delivery request with a ringback message, wherein the ringback message instructs the sender of the call delivery request to generate ringback to the calling party terminating device. 
     In another aspect, the call setups are initiated consecutively to each of the plurality of potential terminating devices. A call setup leg is extended to the consecutively initiated call setups in response to a received provisional response, wherein the received provisional response provides call station information to be used for establishing a bearer path. Upon detecting a first potential terminating device to complete the call setup, initiation of a subsequent call setup (or setups) to the remaining terminating devices is foregone. 
     In yet another aspect, the call setup is concurrently initiated to each of the plurality of potential terminating devices concurrently initiating. A call setup leg is extended to each of the concurrently initiated call setups in response to a received provisional response, wherein the received provisional response provides call station information that is to be used for establishing a bearer path. Upon detecting a first potential terminating device to complete the call setup, the call setup is released to any of the remaining potential terminating devices. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a functional block diagram of a communication network formed according to an embodiment of the invention; 
         FIG. 2  is a functional block diagram of an MSCe according to an embodiment of the invention; 
         FIG. 3  is a functional block diagram of a multiple-termination call delivery to mobile stations according to an embodiment of the invention; 
         FIG. 4  is a signal flow diagram illustrating call delivery for concurrent multiple-termination routing according to one embodiment of the present invention; 
         FIG. 5  is a signal flow diagram illustrating the call feature retrieval of signaling steps of  FIG. 4 ; 
         FIG. 6  is a signal flow diagram illustrating the ringing management signal sequence of  FIG. 4 ; 
         FIG. 7  is a signal flow diagram illustrating the session progress signal sequence of  FIG. 4 ; 
         FIG. 8  is a signal sequence illustrating releasing the call setups to the remaining potential terminating devices of  FIG. 4 ; 
         FIG. 9  is a functional block diagram of a multiple-termination call delivery with a mobile termination and a PSTN termination according to an embodiment of the invention; 
         FIG. 10  is a signal flow diagram  400  illustrating call delivery for concurrent multiple-termination routing including a mobile termination and a PSTN termination according to an embodiment of the invention; 
         FIG. 11  is a signal flow diagram illustrating retrieve call features of  FIG. 10 ; 
         FIG. 12  is a signal flow diagram illustrating the ringing management signal sequence of  FIG. 10 ; 
         FIG. 13  is a signal flow diagram illustrating the detailed session progress signal sequence of  FIG. 10 ; 
         FIG. 14  is a signal flow diagram illustrating the release of the call setups to the remaining potential terminating devices of  FIG. 10 ; 
         FIGS. 15   a  and  15   b  are a signal flow diagram illustrating call delivery for consecutive multiple-termination routing according to an embodiment of the invention; 
         FIG. 16  is a signal flow diagram illustrating the retrieve call features signal sequence of  FIG. 15   a;    
         FIG. 17  is a signal flow diagram illustrating the ringing management signal sequence of  FIG. 15   a;    
         FIG. 18  is a signal flow diagram illustrating the detailed session progress signal sequence of  FIG. 15   a;    
         FIG. 19  is a signal sequence illustrating releasing the call setup of a potential terminating device of  FIG. 15   a;    
         FIG. 20  is a signal flow diagram illustrating the next call features retrieval of signaling steps of  FIG. 15   b;    
         FIG. 21  is a signal flow diagram illustrating the ringing management signal sequence of  FIG. 15   b;    
         FIG. 22  is a signal flow diagram illustrating the detailed session progress signal sequence of  FIG. 15   b ; and 
         FIG. 23  is a flow chart of a method for call delivery for consecutive multiple-termination routing according to an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a functional block diagram of a communication network formed according to an embodiment of the invention. The wireless communication network environment  10  is a next generational network that includes known components that, in addition to legacy network protocols (such as Integrated Services Digital Network User Part (“ISUP”), the call control portion of Signaling System 7), also utilizes the Internet Protocol (“IP”) as a network transport and IP-based call control protocols (for example, the Session Initiation Protocol (“SIP”)). The wireless communication network environment  10  may be employed to support both legacy mobile terminals and next generation mobile terminals within next generation wireless communication systems and further to properly service next generation terminals within next generation networks that have subscribed legacy networks services deploying legacy protocols in combination with IP-based signaling protocols that create additional complexity and processing obstacles to provide features that were taken for granted in legacy networks. 
     The communications network  10  includes a code division multiple access (“CDMA”) wireless access link that can use SIP and Internet Protocol (“IP”) for call origination and termination operations. An example of such a network is a Legacy Mobile Station Domain (“LMSD”). As one of ordinary in the skill would appreciate, other mobile wireless networks may be deployed. The wireless communications network is accessed with respect to the placement of a call to a mobile subscriber or by the initiation of a call by the mobile subscriber, and may be implemented by a variety of devices, such as a computer-based device, another mobile station, and/or a landline terminal. 
     Though a communications network may be modified and/or evolved to accommodate newer features, such as the multimedia data communications, support for maintaining legacy network features is also desired. For example, one such feature is multiple-termination routing, which allows a subscriber to be contacted simultaneously at multiple phone numbers, including home and office phones, mobile phones, and/or pagers, that are arranged and/or sequenced in a member list which contains information as to initiating concurrent and/or consecutive call setups with respect to the devices. Callers reach the subscriber by dialing a single called number. The call setup is completed on the first phone that answers, whether in a concurrent fashion that causes all of the members in the member list to be alerted, in a consecutive fashion where the members are successively alerted until a call is completed on the first phone that answers, and/or a mixture of concurrent and consecutive alerting. Completion of the call setup may occur through a subscriber answering the alerting terminal, through the alerting terminal entering a voice mail mode of operation, through a no-answer basis that allows the subscriber to determine how they want “no answer” calls to be handled, for example, forwarded to voice mail, et cetera. 
     The wireless communications network environment  10  includes a call initiation network  11 , a packet network  22 , a public switched telephone network (“PSTN”)  32 , and an originating/serving network  13 . The call initiation network supports calls initiated by the mobile station  12  and originating/serving network  13 , supports the call terminating devices, mobile stations  40  and  46 . The call initiation network  11  includes a mobile switching center emulation (“MSCe”)  18 , a home location register/visitor location register  24 , a base station  16 , media gateway (“MGW”)  20  and a mobile station  12 . The originating/serving network  13  includes MGW  26 , base stations  36  and  42 , an MSCe  28 , a HLR/VLR  30 , and mobile stations  40  and  46 . 
     The call initiation network  11  and the originating serving network  13  interwork with other networks that include a packet network  22  and a public switched telephone network (“PSTN”)  32  which is coupled to a landline terminal  34 . The packet network  22  and the PSTN  32  provide access to other networks and/or termination devices beyond those illustrated in the example provided. 
     The packet network  22  is a data network where data, arranged in a packet form, is routed between nodes over data links that may be shared between the nodes. An example of a packet network  22  include the Public Internet (which uses Internet Protocol (“IP”) based communications), Asynchronous Transfer Mode (“ATM”) based networks, et cetera. 
     The PSTN  32  is a network based upon circuit switching methodologies where dedicated connections between nodes are established for the duration of a communication dialog, such as with the local, long distance, and international phone systems. The PSTN uses intelligent network protocols for call delivery, such as the Signaling System No. 7 (“SS #7”). Intelligent networking is a method for providing and interpreting information within a distributed network. The North American variant of this protocol is referred to as “SS7” (without the “#”). The SS7 protocol employs a dedicated data circuit to carry packetized machine language messages about each call connected between and among machines of a network to achieve connection control. Intelligent network applications are built upon this protocol, and include call control and transaction capabilities that support database access as well as a variety of intelligent network functions and wireless telecommunications services. 
     With respect to wireless mobile communications networks (such as those under the TIA-136 and TIA-2000 specifications) utilize ANSI-41 as a signaling protocol that provides transaction-based operations to support subscriber mobility in the wireless telecommunications network. In the call initiation network  11 , the base station  16 , the MSC  18 , MGW  20 , and the HLR/VLR  24  provide subscriber mobility services to the mobile station  12 . ANSI-41 allows a subscriber to move between networks while a call is in progress, allows subscribers to originate calls while roaming (that is, operating their mobile devices in a system other than the home system where the subscription was established), allows subscribers to receive calls while roaming, and allows subscribers to activate and use supplementary call features while roaming (for example, call forwarding). 
     A mobile station  12  is coupled to the call initiation network  11  through a base station  16  by the communication link  14 . Communication link  14  is a wireless link. The base station  16  includes a base station controller and a base station transceiver (that is, radio receiver and transmitter) to provide the communication link  14 . The base station  16  is further coupled to a mobile switching center emulation (MSCe)  18 . The MSCe  18  provides the signaling functionality equivalent to that defined for a legacy MSC (that is, a 3GPP2 call control entity that only supports circuit-switched operations). Part of the signaling functionality supported by MSCe  18  includes the establishment, maintenance and termination of voice calls, the ability to modify an established call (for example, establishing three-way call after establishing a two-way call), and triggers to other network elements for the support of subscriber specific features (for example, prepaid calling). The MSCe  18  is coupled to the packet network  22  and the PSTN  32 . The packet network  22  provides signaling connectivity (such as SIP connectivity) to other mobile communications networks, such as a LMSD network. The PSTN  32  provides signaling connectivity to landline devices, such as the landline terminal  34 . The MGW  20  is coupled to base station  16 , the packet network  22  and the PSTN  32 . 
     The MGW  20  provides the bearer functionality for voice calls in the call initiation network  11 . An example of bearer functionality includes the conversion of a voice data format, such as enhanced variable rate codec (“EVRC”), into another voice data format, such as ITU-T (International Telecommunication Union-Telecommunication Standardization Sector) G.711. Such voice data formats are used when a voice call is established between the mobile station  12  through the base station  16 , and the landline terminal  34  through the PSTN  32 . Also, the MGW  20  supports the bearer traffic connectivity (for example, IP connectivity) to other mobile station communication networks, such as a LMSD, though packet network  22 , and to landline devices through PSTN  32 . The MGW  20  is also coupled to MSCe  18 , which controls the bearer resources of MGW  20  through signaling (for example, the MEdia GAteway COntrol protocol (“MEGACO”) or the ITU-T recommendation for MEGACO, which is H.248). Generally, under MEGACO, the commands apply to terminations that are related to a “context.” A termination sources and/or sinks one or more streams of information. A context is an association between a collection of Terminations. The context describes the topology (that is who hear/sees whom) and the media mixing and/or switching parameters for the cases where more than two terminations are involved with this association Contexts are modified using the Add, Subtract, and Modify commands of H.248, with a connection created when two or more terminations are placed in a common context. The MSCe  18  retrieves subscriber and location information for the mobile stations it presently serves from the HLR/VLR  24 . 
     With respect to the originating/serving network  13 , the mobile station  40  communicates over a communication link  38  with a base station  36 , and the mobile station  46  communicates over a communication link  44  to the base station  42 . The base station  36  and the base station  42  access the MSCe  28  for supporting subscriber services. The MSCe  28  accesses the HLR/VLR  30  for subscriber and location information to mobiles stations it presently serves, such as mobile station  40  and mobile station  46 . Though the MSCe  28  includes an Originating MSCe  48  and a Serving MSCe  50 , the originating and serving components of the MSCe may exist as separate units. The multiple-termination routing operation and function of the Originating MSCe  48  will be described in detail with reference to  FIGS. 3 through 23 . 
     The MSCe  28  provides the signaling functionality to support subscriber services (for example, the delivery of a voice call to the mobile station  40 ). The MSCe  28  is coupled to the packet network  22  and the PSTN  32 . For signaling connectivity (for example, SIP connectivity) to other mobile station communications networks, such as a LMSD, the packet network  22  is utilized. The PSTN  32  provides signaling connectivity (for example, Integrated Services Digital Network User Part (“ISUP”) connectivity) to landline devices, such as the landline terminal  34 . 
     The MGW  26  provides the bearer functionality for voice calls in the originating/serving network  13 . The MGW  26  is coupled to base station  36 , the packet network  22  and the PSTN  32 . The MGW  26  supports the bearer traffic connectivity (for example, IP connectivity) to other mobile station networks, such as a LMSD network, though the packet network  22  and to landline devices through the PSTN  32 . The MGW  26  is also coupled to the MSCe  28 , which controls the bearer resources of MGW  27  through signaling protocols (for example, MEGACO and/or H.248). 
     The MGW  27  also provides the bearer functionality for voice calls in the originating/serving network  13 . The MGW  27  is coupled to base station  42 , the packet network  22  and the PSTN  32 . The MGW  27  supports the bearer traffic connectivity (for example, IP connectivity) to other mobile station networks, such as a LMSD network, though the packet network  22  and to landline devices through the PSTN  32 . The MGW  27  is also coupled to the MSCe  28 , which controls the bearer resources of MGW  27  through signaling protocols (for example, MEGACO and/or H.248). 
     In operation, when the mobile station  12  initiates a call to the mobile station  40  via its called number, the network  10  engages in the necessary signaling for termination routing to the mobile station  40 . In the case where a multiple-termination routing is not present (that is, a one-to-many termination routing) the MSCe  18  configures the bearer resources in MGW  20 , the base station  16 , and mobile station  12  based upon information returned by MSCe  28 . 
     With the wireless communication network environment  10 , utilizing IP-based signaling protocols (for example, SIP) in combination with legacy network signaling protocols such as ANSI-41, additional complexity and processing exists to provide features otherwise taken for granted in legacy networks limited to deploying legacy signaling protocols such as ISUP and/or ANSI-41. The provisioning of multiple-termination routing involves accommodating the various subscriber services associated with a unique subscriber identifier (such as the Directory Number, the Mobile Identification Number, the Equipment Serial Number, etc.). 
     For example, for multiple-termination routing, if the called number placed by the mobile station  12  is associated with the mobile station  40 , a multiple-termination routing feature may be present with respect to the call being completed with not only alerts mobile station  40  that a call from mobile station  12  is being attempted, but also alerts mobile station  46  and the landline terminal  34 . The Originating MSCe  48  accommodates multiple-termination routing for the originating/serving network  13 . In general, upon receiving a call delivery request  23  for a called number from the packet network  22  and/or a call delivery request  33  from the PSTN  32 , the Originating MSCe  48  has the capability to access the subscriber feature subscription using the home location register  52  and the visitor location register  54  for call features associated with the called number in the call delivery request. The call features may include multiple-termination routing information as part of the subscriber feature subscription. When the call features include multiple-termination routing information, the MSCe  28  has the capability to initiate the multiple independent call setups to provide this subscriber feature accordingly. 
       FIG. 2  is a functional block diagram of the MSCe  28  that includes a processing module  60 , a memory  62 , a peripheral bus interface  70 , and network interfaces  72  through  80 . The processing module  60 , in combination with operational instructions stored in memory  62  and accessed via the bus  61 , executes MSCe functions. The MSCe functions include, but are not limited to, basic switching functions, call establishment coordination to and from wireless subscribers, transmission facilities management, mobility management, and/or call processing functions. The MSCe  28  may be implemented using a shared processing device, individual processing devices, or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on operational instructions. The memory  62  may be a single memory device or a plurality of memory devices. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, and/or any device that stores digital information. 
     The memory  62  can include a transcoder list  64 , ringback logic  66 , and operation logic  68 . The operation logic includes logic for communicating through at least one network interface utilizing standardized protocols. The MSCe  28  includes a plurality of network ports labeled as network I/Fs (interfaces)  72 - 80 . For intercommunication, the MSCe  28  receives a list of transcoders from a mobile station through one of the network interfaces  72 - 80 , and the MSCe  28  forwards the list of transcoders through the network  10  through another interface of the network interface  72 - 80 . The MSCe  28  also determines whether to generate a ringback or whether to allow another MSCe (such as MSCe  18 ) to generate ringback to the calling party. In the described embodiment, MSCe  28  includes operational logic that enables it to act as an Originating MSCe  48 , and/or a terminating (serving) MSCe  50 . 
       FIG. 3  is a functional block diagram of a multiple-termination call delivery  100  to mobile stations serviced by the base station  36  and the base station  42 . The multiple-termination call delivery  100  includes an MSCe  28 , a HLR/VLR  30 , media gateways  26  and  27 , and base station  36  that services mobile station  40 , and base station  42  that services mobile station  46 . The MSCe  28  includes a Serving MSCe  50  and an Originating MSCe  48 . The Originating MSCe  48  provides the multiple-termination call delivery capability. 
     The HLR/VLR  30  includes a home location register  52  and a visitor location register  54 . The HLR  52  and the VLR  54  may be located with each other, or as separate network elements. The home location register  52  is the location register to which a user identity is assigned for record purposes such as subscriber information. Subscriber information includes items such as location information, subscriber status, subscribed features, and directory numbers. An HLR may serve one or more MSCs and/or MSCes 
     The visitor location register  54  is the location register other than the HLR used by an MSC or MSCe to retrieve subscriber information for handling of services for a visiting subscriber. A service provider populates a visitor location register  54  initially, and is subsequently populated with visiting subscribers as they roam into, and out of, the coverage area served by the visitor location register  54 . A visiting subscriber is a subscriber having services provided by a network outside of it home service area. The visitor location register  54  may serve one or more MSCs and/or MSCes. 
     The MSCe  28 , in the present example, has an Originating MSCe  48  and a Serving MSCe  50 . The “emulator” designation for the MSCe indicates the packet implementation of an MSC, though bearer data is not “switched” in the sense of a conventional MSC. The Originating MSCe  48  and the Serving MSCe  50  may be present in the same MSCe  28  or in a separate MSCe across a network. For simplicity of example, the originating and the Serving MSCe  50  are shown as being present in the MSCe  28 . When a mobile station becomes operational within an area serviced by the MSCe  28 , the visitor location register  54  temporarily stores subscriber information obtained from the home location register  52  that relates to the mobile station. The Serving MSCe  50  uses this subscriber information to provide services to the mobile station while it operates within the service coverage area of Serving MSCe  50 . 
     In operation, a call delivery request  101 , which includes a called number, is provided to the Originating MSCe  48 . The Originating MSCe  48  may receive the call delivery request  101  from the packet network  22  (for example, the call delivery request  23  is a SIP INVITE request), or from the PSTN  32  (for example, the call delivery request  33  is an ISUP Initial Address Message (“IAM”)). In response to the call delivery request, the Originating MSCe  48  makes a request  102  to HLR/VLR  30  to obtain any call features associated with the called number and information as to how the Originating MSCe  48  should respond to the call setup request. The call features may include multiple-termination routing information. This information includes a member list and termination triggers. The member list provides a list of potential terminating devices, and may also designate the termination sequence for initiating the call sequence. The call sequence may be for consecutive call setups, concurrent call setups to each of the members, and/or a mixture thereof. In the present example, the members include mobile station  40  and mobile station  46 , and the member list provides for concurrent, and/or consecutive, call setups to the terminating devices. Consecutive call setups are described in detail with reference to  FIGS. 15 through 22 . Based upon its subscriber information (for example location information), the home location register  52  retrieves termination information for the mobile station  40  at  104   a  and  105   a , and for the mobile station  46  at  104   b  and  105   b  via the visitor location register  54 . The HLR/VLR  30  returns call features associated with the called number in response  106 . 
     Having retrieved the call features, the Originating MSCe  48  determines whether the call features include multiple-termination routing information to a plurality of potential terminating devices. Such determination, for example, is the presence of a TERMLIST parameter from an ANSI-41 location request response (“locreq”). When the call features include multiple-termination routing information, the Originating MSCe  48  initiates a call setup to each of the potential terminating devices. Using the routing information, the Originating MSCe can determine whether the terminating device is being served by another MSCe. When the terminating device is being served by an MSCe, the Originating MSCe  48  uses SIP for the call control protocol. In the present example both mobile station  40  and mobile station  46  are being served by the MSCe  48 . Based upon the TERMLIST information, that is concurrent call setups, the Originating MSCe sends a SIP setup request at  107   a  and at  107   b  to the Serving MSCe  50 . 
     Based upon internal information received while mobile station  40  and mobile station  46  are operating within the service area of the Serving MSCe  50 , the Serving MSCe  50  attempts to contact the mobiles. The Serving MSCe  50  initiates an access setup to the base station  36  at  108   a  and to the base station  42  at  108   b . After mobile  40  responses base station  36  send  109   a  to the Serving MSCe  50 . After mobile station  46  responses base station  42  sends  109   b  to the Serving MSCe  50 . In preparation for the call path with any of the mobile stations, the Serving MSCe  50  sends a signaling message  110   a , for example a H.248 ADD command, to the media gateway  27  to setup bearer resources to support a call setup to mobile station  46 . The media gateway acknowledges the bearer resource setup with signaling message  111   a  sent to the Serving MSCe  50 . The Serving MSCe sends a signaling message  110   b , for example a H.248 ADD command, to the media gateway  26  to setup bearer resources to support a call setup to mobile station  40 . The media gateway acknowledges the bearer resource setup with signaling message  111   b  sent to the Serving MSCe  50 . 
     The call setup status for each of the potential terminating devices, mobile station  42  and mobile station  46 , is provided to the Originating MSCe  48  via the SIP setup ACK  112   a  and  112   b . In this instance, the call setup is completed by the mobile station  40 , as in having been “answered.” The base station  36  informs the Serving MSCe  50  by sending  113 . In response to  113 , SIP setup response  114  is sent to Originating MSCe. The Originating MSCe  48  completes the call setup by sending the call setup response  115  containing information about the first responder, mobile station  40 . The Originating MSCe  48  releases the remaining potential terminating device, mobile station  46 , and any bearer resources allocated to the call setup to mobile station  46 . 
       FIG. 4  is a signal flow diagram  200  illustrating call delivery for concurrent multiple-termination routing via the base station  36  and the base station  42 . Although the signal flow diagram  200  illustrates a concurrent multiple-termination routing for two mobile stations, one of ordinary skill in the art would appreciate that additional multiple-terminations may be used. 
     The SIP protocol is an IP based call control protocol set out by the Internet Engineering Task Force (“IETF”) Request-For-Comment (“RFC”) 3261. SIP-T is set out by IETF RFC 3372 regarding encapsulating ISUP messages (for example, as defined by ITU-T Q.763 or Alliance for Telecommunications Industry Solutions PP-1000113.2005) within SIP. ISUP messaging is used as circuit-switched (for example a SS7 based network) call control protocol. ISUP messaging is used to set-up, manage, and release trunk circuits that carry voice and data calls over a PSTN. The SIP-T/SIP convention is used to denote that a SIP message may include an encapsulated ISUP message. SIP-T/SIP messages may also include a payload. An example of a SIP payload is an SDP (Session Description Protocol) message. A SDP message, is a short structured textual description of the name and purpose of the session, and the media, protocols, codec (code/decode) formats, timing and transport information that are required to decide whether a session is likely to be of interest and to know how to start media tools to participate in the session. The information within a SDP message is set out in IETF RFC 2327. 
     For ANSI-41 commands, the ANSI-41 convention for operation component acronyms is used. For example, the Invoke component acronym is in all-capital letters (for example, “LOCREQ”), while the return result component acronym is in all-lowercase letters (for example, “locreq”). Also, IP terminals at the media gateways and the base stations are illustrated as numbers inside small ovals. The terminals are numbered for so that the various call segments may be more easily referenced. The description of  FIGS. 4 through 8  and  10  through  23  is organized according to the particular events identified by corresponding numerical identifiers:
       201  The Originating MSCe  48  receives an INVITE (per RFC 3261) message that includes a SDP message, labeled SDP-4, and a called number. The INVITE may include an encapsulated Initial Address Message (“IAM”). The Originating MSCe  48  is the MSCe that owns the called number dialed by the calling party (for example, mobile station  12 ).     202 . The Originating MSCe  48  sends a LOCREQ to the home location register  52  associated with called number. The Originating MSCe  48  may optionally include a TransactionCapability parameter to specify the appropriate termination handling.     203 - 10  The call features associated with the called number are retrieved via the home location register  52 . Retrieval of the call features will be discussed in detail with reference to  FIG. 5 .     211  When all routreqs are received by the home location register  52 , it returns a locreq to the Originating MSCe  48 . The locreq includes multiple-termination routing information in the form of the TerminationList (“TERMLIST”) parameter, along with an indication of the reason for extending the incoming call (that is, for multiple-termination routing) in the DMH_RedirectionIndicator (“REDIND”) parameter. The TerminationList parameter includes a member list providing the plurality of potential terminating devices, and termination triggers that indicates when to request further instructions on call processing relating to each of the devices where call setups are being initiated. In this scenario the TerminationList member list includes two terminations: an intersystem termination for the first member, mobile station  40 , and an intersystem termination for the second member, mobile station  46 . The information indicates the sequence of call processing instructions to initiate a consecutive sequence of call setups.     212  After receiving the locreq in signaling step  211 , the Originating MSCe  48  initiates a call setup to each of the plurality of potential terminating devices (that is, mobile station  40  and mobile station  46 ). Upon analyzing the intersystem termination information the Originating MSCe  48  determines that both of the intersystem terminations are associated with an MSCe and thus SIP-T/SIP will be used for call setups to the MSCe serving the termination-devices. For mobile station  40 , the Originating MSCe  48  sends an INVITE message to the Serving MSCe  50  including Call-ID1, TLDN1 (“Temporary Local Directory Number”) and SDP-4. The INVITE may include an encapsulated ISUP IAM message. Note that the Originating MSCe  48  may elect to modify SDP-4 as received in Step  201 . Note that this INVITE request is for the establishment of a Dialog between the Originating MSCe  48  and the Serving MSCe  50  and is a different Dialog than that related to the INVITE request of signaling step  201  received by the Originating MSCe  48 . The dialog between Originating MSCe  48  and the Serving MSCe  50  for a call setup to mobile station  40  is identified by Call-ID1. The Serving MSCe  50  will use TDLN1 to make the association with MSID1 received in the ROUTREQ message ( FIG. 5 , Step  204 ).     213  After receiving the locreq at signaling step  211 , for initiating a call setup to the mobile station  46 , the Originating MSCe  48  sends an INVITE message to the Serving MSCe  50  including Call-ID2, TLDN2 and SDP-4. The INVITE may include an encapsulated ISUP IAM message. Note that the Originating MSCe  48  may elect to modify SDP-4 that was received in signaling step  201 . Note that this INVITE request is for the establishment of a Dialog between the Originating MSCe  48  and the Serving MSCe  50  and is a different Dialog than that related to the INVITE request of signaling step  201  received by the Originating MSCe  48 . The dialog between Originating MSCe  48  and the Serving MSCe  50  for a call setup to mobile station  46  is identified by Call-ID2. The Serving MSCe  50  will use the TDLN2 to make the association with MSID2 received in response to the ROUTREQ message (see  FIG. 5 , step  206 ).     214  After receiving the locreq in signaling step  211 , if the INVITE request of signaling step  201  did not include an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message to the originator of the INVITE request of signaling step  201 . The SIP informational class of responses “1xx” is used to indicate call setup progress.
       When the INVITE request at signaling step  201  includes an ISUP IAM Message the Originating MSCe  48  may send either a 180 Ringing message or a 183 Session Progress message including an ISUP Address Complete (“ACM”) message to the originator of the INVITE request of signaling step  201 .   
       

     If the Originating MSCe  48  elects to initiate local ringback (that is have ringback generated and sent to calling party by the originator of the INVITE request at signaling step  201 ), then a 180 Ringing message is sent to the originator of the INVITE request of signaling step  201 ; otherwise a 183 Session Progress message is sent. In this regard, when the call delivery request of signaling step  201  is a SIP INVITE, the Originating MSCe  48  responds to the received call delivery request with a ringback message that instructs the sender of the call delivery request to generate ringback to the calling party terminating device. For a call setup to a single terminating device, the Serving MSCe is serving the terminating device controls all aspects of ringback to the calling party. When multiple-termination routing is performed the control logic within Originating MSCe  48  controls all aspects of ringback to the calling party.
       215  In response to the 180 Ringing or 183 Session Progress message, a provisional acknowledgement (“PRACK”) message  215 , is sent to the Originating MSCe  48 . PRACK is used to acknowledge receipt of a SIP provisional response. In some scenarios, like voice calls, it is critical that the network serving the called party known that the call state information within a SIP provisional response has been received by the network serving the calling party. The use of PRACK is set out in IETF RFC 3262.     216  The Originating MSCe  48  sends a 200 OK response to the PRACK message,  215 . The 200 OK response stops any retransmissions of the PRACK message.     217 - 22  The ringing management between the originating MSCe  48  and the Serving MSCe  50  operates to permit sufficient time for the call setups to the potential terminating devices, which in this example are mobile stations  40  and  46 . Ringing management  217 - 22  will be discussed in detail with reference to  FIG. 6 .     223 - 24  After receiving the INVITE message of signaling step  212 , the Serving MSCe  50  sends a PAGING REQUEST message (under the Interoperability Specification (“IOS”) for CDMA2000 access network interfaces) to the base station  36  to initiate a mobile terminated call setup scenario for the mobile station associated with TLDN1 (that is, mobile station  40 ). The PAGING REQUEST message includes the “Desired Codec” for the mobile station  40 . The IOS protocol is used to pass information between an MSCe and a Base Station (BS). The messaging formats and procedures for this protocol are set out in the 3GPP2 A.S0011-C through A.S0017-C, or updates revisions, of these documents.
       When the mobile station  40  responds to the page, a PAGING RESPONSE message is sent from the serving base station  36  to the Serving MSCe  50 . The PAGING RESPONSE message includes the codec chosen by the mobile station  40 . The PAGING RESPONSE message may include a list of available BS transcoders, and the connection information, for example the IP address and port number, for the base station  36  communications channel at termination  7 .   
         225 - 26  After receiving the INVITE message of signaling step  213 , the Serving MSCe  50  sends a PAGING REQUEST message to the base station  42  to initiate a mobile terminated call setup scenario for the mobile station associated with TLDN2 (that is, mobile station  46 ). The PAGING REQUEST message includes the “Desired Codec” for the mobile station  46 .
       When a terminating mobile station responds to the page, a PAGING RESPONSE message is sent from the serving base station  42  to the Serving MSCe  50 . The PAGING RESPONSE message includes the codec chosen by the terminating mobile station  46 . The PAGING RESPONSE message may include a list of available base station transcoders, and the connection information for the base station  42  communications channel at termination  11 .   
         227  With respect to the mobile station  40 , the Serving MSCe  50  establishes a context with media gateway (“MGW”)  26 . The H.248 message sent from the Serving MSCe  50  to MGW  26  includes two ADD commands The first ADD command establishes a termination for a bearer channel using RTP (“Real-time Transport Protocol”) towards the packet network  22 . The mode is set to sendrecv. If the Serving MSCe  50  elects to initiate Termination-Side ringback (that is, ringback sent to the calling party generated by the network presently serving the called party), then ringback from termination  5  is initiated. The first ADD command includes a SDP-4, which is the remote SDP including the connection information for the bearer entity supporting the calling party (for example MGW  20  supporting a call initiated by mobile station  12 ). Connection information may include an IP Address and a User Datagram Protocol (“UDP”) Port number.
       Note that the ringback tone generated by the MGW  26  will not be received by the calling party. As mentioned in step  214  the Originating MSCe  48  controls all aspects of ringback to the calling party for multiple-termination routing scenarios. The bearer entity supporting the calling party will not allow received data to be passed to the calling party until the bearer entity is assured that the data is coming from a trusted source. The Originating MSCe  48  controls the flow of all messaging to the network entities support the calling party. It is only when the Originating MSCe  48  sends a 200 OK (INVITE) including a SDP (with the connection information of the trusted source) that is in response to the SIP INVITE of signaling step  201  will the bearer entity supporting the calling party will allow received bearer data to be passed to the calling party.   
       

     The first ADD command may also contain a BT (Bearer Timer) parameter indicating, in seconds, the length of time MGW  26  waits without receiving data from the connection endpoint defined in SDP-4 before applying an error treatment to termination  5  (for example removing termination  5  from the bearer channel using RTP towards the packet network  22  and sending a message to the Serving MSCe  50  informing it of the action). The Serving MSCe  50 , from the LEGINFO1 parameter in the Routereq message (signaling step  204 ), is aware that the call associated with TLDN1 is one termination of a multiple-termination routing scenario. In general the call setup time of a multiple-termination routing scenario is greater than the call setup time of a single termination scenario. The Serving MSCe  50  may, on a per call setup basis, adjust the value of BT based on knowledge it may have about the call setup. 
     The second ADD command establishes a termination for the base station  36  communication channel with a mode set to sendrecv (a bi-directional connection). The second ADD command includes SDP-7, which is the remote SDP including the base station  36  connection information (that is information sent in signaling step  224  that relates to termination  7 ).
       228  The MGW  20  replies to the H.248 message of signaling step  227  by sending a H.248 Reply message to the Serving MSCe  50 . The Reply message includes a SDP-5 and SDP-6. The SDP-5 is the local SDP for the termination given in SDP-4 and includes the MGW  20  connection information for termination  5 . The SDP-6 is the local SDP for the termination towards the base station  36  and includes the MGW  26  connection information (for example, the IP address and the UDP Port number) for termination  6 .     229  With respect to the mobile station  46 , the Serving MSCe  50  establishes a context with the MGW  27 . The H.248 message sent from the Serving MSCe  50  to MGW  27  includes two ADD commands. The first ADD command establishes a termination for a bearer channel using RTP towards the packet network  22 . The termination mode is set to sendrecv. If the Serving MSCe  50  elects to initiate Termination-Side ringback, then ringback from termination  9  is initiated. The first ADD command includes SDP-4, which is the remote SDP including the connection information for the bearer entity supporting the calling party (for example, the MGW  20  supporting a call initiated by the mobile station  12 ). Connection information may include an IP Address and a User Datagram Protocol (“UDP”) Port number).
       Note that the ringback tone generated by the MGW  27  will not be received by the calling party. As mentioned in step  214  the Originating MSCe  48  controls all aspects of ringback to the calling party for multiple-termination routing scenarios. The bearer entity supporting the calling party will not allow received data to be passed to the calling party until the bearer entity is assured that the data is coming from a trusted source. The Originating MSCe  48  controls the flow of all messaging to the network entities that support the calling party. It is only when the Originating MSCe  48  sends a 200 OK (INVITE) including a SDP (with the connection information of the trusted source) that is in response to the SIP INVITE of signaling step  201  will the bearer entity supporting the calling party will allow received bearer data to be passed to the calling party.
           The first ADD command may also contain a BT (Bearer Timer) parameter indicating, in seconds, the length of time MGW  26  waits without receiving data from the connection endpoint defined in SDP-4 before applying an error treatment to termination  9  (for example removing termination  9  from the bearer channel using RTP towards the packet network  22  and sending a message to the Serving MSCe  50  informing it of the action). The Serving MSCe  50 , from the LEGINFO2 parameter in the Routereq message (signaling step  206 ), is aware that the call associated with TLDN2 is one termination of a multiple-termination routing scenario. In general the call setup time of a multiple-termination routing scenario is greater than the call setup time of a single termination scenario. The Serving MSCe  50  may, on a per call setup basis, adjust the value of BT based on knowledge it may have about the call setup.   
           The second ADD command establishes a termination for the base station  42  communication channel with a termination mode set to sendrecv (a bi-directional connection). The second ADD command includes SDP-11, which is the remote SDP including the base station  42  connection information (that is information sent in signaling step  226  that relates to the termination  11  of the base station  42 ).   
         230  The MGW replies to the H.248 message of signaling step by sending a H.248 Reply message to the Serving MSCe  50 . The Reply message includes SDP-9 and SDP-10. The SDP-9 is the local SDP for the termination given in SDP 4 and includes MGW  27  connection information for the termination  9 . The SDP-10 is the local SDP for the termination towards base station  42  and includes the connection information (for example, IP address and UDP Port number) for termination  10 .     231 - 36  The session progress signaling addresses the handshake operation between the Serving MSCe  50  and the Originating MSCe  48 . The handshake operation between the Originating MSCe  48  and the Serving MSCe  50  operates to provide connection management for the call setups. The session progress signaling is not forwarded through, as would occur with single termination call setups. The session progress signaling  231 - 36  will be discussed in detail with reference to  FIG. 7 .     237  After receiving the Reply message of signaling step  228 , the Serving MSCe  50  sends an IOS Assignment Request message to the base station  36  to request assignment of radio resources. The Assignment Request message includes MGW  26  connection information (for termination  6 , obtained from signaling step  228 ), the request of any base station  36  transcoding (if necessary) and the codec assignment for the mobile station associated with TDLN1 (that is, mobile station  40 ).     238  After receiving an Assignment Request message at signaling step  237 , the base station  36  sends the IOS Assignment Complete message to the Serving MSCe  50 .     239  After receiving the Reply message at signaling step  230 , the Serving MSCe  50  sends an IOS Assignment Request message to the base station  42  to request assignment of radio resources. The Assignment Request message includes the MGW  27  connection information (for termination  10 , obtained from signaling step  230 ), the request of any base station  42  transcoding (if necessary), and the codec assignment for the mobile station associated with TDLN2 (that is, mobile station  46 ).     240  After receiving an Assignment Request message at signaling step  239 , the base station  42  sends the IOS Assignment Complete message to the Serving MSCe  50 .     241  Base station  36  sends a Connect message to the Serving MSCe  50  to indicate that the call has been answered by the mobile station associated with TLDN1 (that is, mobile station  40 ).     242  If the Serving MSCe  50  elected to initiate Termination-Side ringback at signaling step  227 , then the Serving MSCe  50  will send a H.248 message to MGW  26 . The H.248 message contains a MODIFY command to deactivate Termination-Side ringback.     243  The MGW  26  acknowledges the H.248 message of signaling step  242  by sending a H.248 Replay message to the Serving MSCe  50 .     244  After receiving the CONNECT message from the base station  36  and the PRACK message is received at signaling step  232  (see  FIG. 7 ), the Serving MSCe  50  sends a 200 OK message to the Originating MSCe  48 . The 200 OK message includes Call-ID1, which identifies to the Originating MSCe  48  that mobile station  40  was the terminating device completing the call setup. When the INVITE request from signaling step  212  for the mobile station  40  includes an ISUP IAM Message then the 200 OK message may include an ISUP Answer (“ANM”) message. The 200 OK message acknowledges that the INVITE (signaling step  212 ) message has succeeded.     245  Upon receiving a 200 OK message from any one of the initiated call setup requests (for example, the INVITE send in signaling step  212  to setup a call to the mobile station  40  or in signaling step  213  to setup a call to mobile station  46 ) the Originating MSCe  48  sends a 200 OK message to the originator of the INVITE request (signaling step  201 ). The 200 OK message including SDP-5 (that is the SDP received in signaling step  231  (see  FIG. 7 ). The 200 Ok message includes SDP-5, instead of SDP-9, for the 200 OK message in signaling step  244  included Call-ID1. When the INVITE request from the initiating network at step  201  includes an ISUP IAM Message, then the 200 OK message may include an ANM message. The 200 OK message acknowledges that the INVITE at signaling step  201  message has succeeded.     246  The Originating MSCe  48  receives an ACK message. The ACK message confirms reception of the final response (that is, 200 OK at signaling step  245 ) for the Dialog identified by Call-ID0.     247  Upon receiving an ACK message at signaling step  246  for the Dialog identified by Call-ID0, the Originating MSCe  48  sends an ACK message to the Serving MSCe  50  to confirm reception of the final response (that is, 200 OK in signaling step  244 ) for the Dialog identified by Call-ID1.     248 - 54  Upon detecting the first potential terminating device to complete the call setup, in this instance mobile station  40 , any call setups to remaining potential terminating device or devices are released. The release signaling steps  248 - 54  will be discussed in detail with reference to  FIG. 8 .   

       FIG. 5  is a signal flow diagram illustrating the call feature retrieval of signaling steps  203 - 210  of  FIG. 4 .
       203 - 06  The home location register  52  recognizes the called number as having a multiple-termination routing feature, and that, based on the received TransactionCapability parameter, received in signaling step  202 , the Originating MSCe  48  is capable of supporting a multiple-termination call. In this scenario, there are the two Mobile Station Identifiers (MSIDs) in the member list are registered in the same system; therefore, two ROUTREQs are sent to the Serving visitor location register  54 , and the visitor location register  54  forwards the ROUTREQs to the Serving MSCe  50 . The MSID is a private, unique identification of the subscriber.     208 - 10  In reaction to each ROUTREQ, the Serving MSCe  50  checks its internal data structures and determines that the mobile stations  40  (associated with MSID1) and mobile station  46  (associated with MSID2) are currently idle (or in similar call-ready states, such as the call is involved in another call, but has a call waiting feature). The Serving MSCe  50  then allocates two TLDNs. TLDN1 is associated with MSID1 and TLDN2 is associated with MSID2. The TLDN values are returned to the visitor location register  54  in a routreq. The visitor location register  54  sends each routreq to the home location register  52 .   

       FIG. 6  is a signal flow diagram illustrating the ringing management signal sequence of  FIG. 4 . In this sequence of step the Originating MSCe  48  receives the SIP provisional responses, indicating that the call setups to mobile station  40  and mobile station  46  are proceeding, from Serving MSCe  50  and acknowledges there reception with SIP PRACK. messages. Unlike a single termination scenario, when the Originating MSCe  48  receives any 18x messages from Serving MSCe  50 , for example indicating a desire for local ringback, the 18x messages are terminated (that is not forward onward) by Originating MSCe  48 :
       217  After receiving the INVITE for a call setup to the mobile station  40  at signaling step  212 , if the INVITE request did not include an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message to the Originating MSCe  48 
       When the INVITE request includes an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message including an ISUP ACM message to the Originating MSCe  48 . The purpose of the ISUP ACM message is to stop any timers in the Originating MSCe  48  that might be associated with the ISUP IAM sent in signaling step  212 .   If the Serving MSC  50  elects to initiate local ringback then the 180 Ringing message is sent.   
         218  In response to the 180 Ringing message or a 183 Session Progress message at signaling step  217 , a PRACK message is sent to the Serving MSCe  50 .     219  The Serving MSCe  50  sends a 200 OK response to the Originating MSCe  48  in response to the PRACK message at signaling step  218 .     220  After receiving the INVITE for the mobile station  46  at signaling step  213 , if the INVITE request did not include an ISUP IAM Message the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message to the Originating MSCe  48 
       When the INVITE request includes an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message including an ISUP ACM message to the Originating MSCe  48 . The purpose of the ISUP ACM message is to stop any timers in the Originating MSCe  48  that might be associated with the ISUP IAM sent in signaling step  213 . The Originating MSCe  48  does not forward the 180 Ringing message and/or the 183 Session Progress message, as may the case in single-termination call setups.   If the Serving MSC  50  elects to initiate local ringback then the 180 Ringing message is sent.   
         221  In response to the 180 Ringing message or a 183 Session Progress message at signaling step  220 , a PRACK message is sent to the Serving MSCe  50 .     222  The Serving MSCe  50  sends a 200 OK response to the Originating MSCe  48  in response to the PRACK message from signaling step  221 .   

       FIG. 7  is a signal flow diagram illustrating the session progress signal sequence of  FIG. 4 . The Originating MSCe  48  coordinates the multiple-termination routing for connection management. In this sequence of signaling steps, the Originating MSCe  48  receives the SIP provisional responses, indicating that the call setups to mobile station  40  and mobile station  46  are proceeding, from Serving MSCe  50  and acknowledges there reception with SIP PRACK messages. Unlike a single termination scenario the Originating MSCe stores any information received, for example SDP messages, in the SIP provisional responses and does not act. When the Originating MSCe  50  receives information as to which terminating device will actually complete the call setup (signaling step  244  which includes Call-ID1) does the Originating MSCe  50  retrieve the appropriate stored information and send it to the signaling entity supporting the calling party.
       231  Upon receiving a Reply message in signaling step  228 , the Serving MSCe  50  sends the Originating MSCe  48  a 183 Session Progress message including SDP-5.
       Note the 183 Session Progress message is not sent to the originator of the INVITE message, signaling step  201 .   
         232  In response to the 183 Session Progress message from signaling step  231 , the Originating MSCe  48  stores SDP-5 and sends a PRACK message to the Serving MSCe  50 .     233  The Serving MSCe  50  sends a response to the PRACK message from signaling step  232  to the Originating MSCe  48 .     234  Upon receiving a Reply message in signaling step  230 , the Serving MSCe  50  sends the Originating MSCe  48  a 183 Session Progress message including SDP-9.
       Note the 183 Session Progress message is not sent to the originator of the INVITE message, signaling step  201 .   
         235  In response to the 183 Session Progress message from signaling step  234 , the Originating sends a PRACK message to the Serving MSCe  50 .     236  The Serving MSCe  50  sends a response to the PRACK message from signaling step  235  to the Originating MSCe  48 .   

       FIG. 8  is a signal sequence illustrating releasing the call setups to the remaining potential terminating devices of  FIG. 4 :
       248  Upon receiving a 200 OK in signaling step  244 , the Originating MSCe  48  releases all other call setup attempts. The Originating MSCe  48  sends an IOS CANCEL message to the Serving MSCe  50 . If the INVITE request for the mobile station  46  in signaling step  213  included an ISUP IAM Message, then the CANCEL message may contain a REL message.     249  The Serving MSCe  50  sends a 487 Request Terminated message to the Originating MSCe  48 . The Message is a response to the INVITE request from signaling step  213 .     250  The Serving MSCe  50  answers the CANCEL request for the mobile station  46  in signaling step  248  by sending a 200 OK message to the Originating MSCe  48 .     251  Upon receiving the CANCEL message of signaling step  248  from the Originating MSCe  248 , the Serving MSCe  50  begins releasing all resources associated with the call setup attempt to the mobile station  46 . The Serving MSCe  50  sends the MGW  27  a H.248 message consisting of two SUBTRACT commands. The first SUBTRACT command removes termination  10  to base station  42 . The second SUBTRACT removes termination  9  for the bearer channel using RTP towards the packet network  22 .     252  The MGW  27  replies to the H.248 message at signaling step  251  by sending Serving MSCe  50  with a H.248 Reply message.     253  Upon receiving the CANCEL message at signaling step  248  from the Originating MSCe  48 , the Serving MSCe  50  sends a Clear Command to the base station  42  to instruct the base station  42  to release the associated dedicated resources.     254  The base station  42  sends a Clear Complete message to the Serving MSCe  50 . The Serving MSCe  50  releases the underlying transport connection.   

       FIG. 9  is a functional block diagram of a multiple-termination call delivery  100  to a mobile station serviced by the base station  36  and a landline terminal serviced by the PSTN  32 . In operation, a call delivery request  301 , which includes a called number, is provided to the Originating MSCe  48 . The Originating MSCe  48  may receive the call setup request  301  from the packet network  22  (for example, the call delivery request  23  is a SIP INVITE request), or from the PSTN  32  (for example, the call delivery request  33  is an ISUP IAM). In response to the call delivery request, the Originating MSCe  48  makes a request  302  to HLR/VLR  30  to obtain any call features associated with the called number and information instruction the nature in which the Originating MSCe  48  should response to the call delivery request. The call features may include multiple-termination routing information, which includes a member list and termination triggers. The member list provides a list of potential terminating devices, and the termination triggers indicate when to request further instructions on call processing relating to each of the devices where call setups are being initiated. The information also provides the call setup sequence with respect to the list of potential terminating devices. The call sequence may be for consecutive call setups to each of the members, concurrent call setups to each of the members, and/or a mixture thereof. 
     In the present example, the member list includes mobile station  40  and the landline terminal  34 , and provides for concurrent call setups. Based upon its subscriber information (for example location information), the home location register  52  retrieves termination information for the mobile station  40  at steps  304  and  305  via the visitor location register  54 . The HLR/VLR  30  returns call features associated with the called number in response  306 . 
     Having retrieved the call features, the Originating MSCe  48  determines whether the call features include multiple-termination routing information to a plurality of potential terminating devices. The Originating MSCe  48  uses the routing information to determine whether the terminating device is being served by another MSCe, a legacy MSC, or if neither, by the PSTN  32 . If the terminating device is being served by an MSCe, the Originating MSCe  48  will use SIP for the call control protocol. If the routing is to the PSTN  32 , the originating MSCe uses ISUP for the call control protocol. In the present example, a MSCe serves the mobile station  40  The Originating MSCe  48  sends a SIP setup request  307   a  to the Serving MSCe  50  to attempt a call setup with mobile station  40 . The Originating MSCe  48  sends signaling message  307   b , for example a H.248 ADD command, to the media gateway  27  to setup bearer resources to support a call setup to landline terminal  34 . The media gateway  27  acknowledges the bearer resource setup with signaling message  307   c  sent to the Originating MSCe  50 . Using the information received in signaling message  307   c , the Originating MSCe  48  sends ISUP signaling, for example an ISUP IAM, to PSTN  32  to attempt a call setup with landline terminal  34 . 
     With respect to the mobile station  40 , the Serving MSCe  50 , initiates an access setup to the base station  36  at  308 . After mobile  40  responds, base station  36 , at  309 , sends an access setup to the Serving MSCe  50 . In preparation for the call path with the mobile station  40 , the Serving MSCe  50  sends a signaling message at  310 , for example, a H.248 ADD command, to the media gateway  26  to set up the bearer resources to support a call setup to the mobile station  40 . The media gateway  26  acknowledges the bearer resource setup with a signaling message at step  311 . 
     The call setup status for mobile station  42  and is provided to the Originating MSCe  48  via the SIP setup ACK at step  312   a . The call status for landline terminal  34  is provided to the Originating MSCe  48  via ISUP at step  312   b . In this instance, the call setup is completed by the mobile station  40 , as in having been answered. The base station  36  informs the Serving MSCe  50  at step  313 . In response to  313 , the SIP setup response at  314  is sent to the Originating MSCe  48  from the Serving MSCe  50 . The Originating MSCe  48  completes the call setup by sending the call setup response at step  315  that includes information about the first responder—in this example, mobile station  40 . The Originating MSCe  48  releases the remaining potential terminating device, landline terminal  34 , and any bearer resources (for example, those bearer resources in Media Gateway  27 ) that were allocated to the call setup to the landline terminal  34 . 
       FIG. 10  is a signal flow diagram  400  illustrating call delivery for concurrent multiple-termination routing via the base station  36  and the PSTN  32 . For purposes of this example, the mobile station  40 , serviced by the base station  36 , is presently served by a MSCe other than the Originating MSCe  48 . The Originating MSCe  48  is defined as the home MSCe for the called number from the initiating device. Because the second member of the member list is a PSTN directory number, a media gateway  27  is required in the originating/serving network  13  to support the PSTN call setup. In this example, the mobile station  40  completes (that is, answers) the call setup first and thus the PSTN call setup is abandoned:
       401 . The Originating MSCe  48  receives an INVITE message including a SDP message labeled SDP-4 and a called number. The INVITE may contain an encapsulated ISUP IAM.     402 . The Originating MSCe  48  sends a LOCREQ to the HLR associated with the called number. The Originating MSCe  48  may optionally include the TransactionCapability parameter to specify the appropriate termination handling.     403 - 06  The call features associated with the called number are retrieved via the HLR  52 . Retrieval of the call features will be discussed in detail with reference to  FIG. 11 .     407  When all routreqs are received by the home location register  52 , it returns a locreq to the Originating MSCe  48 . The locreq includes multiple-termination routing information in the form of the TerminationList parameter (“TERMLIST”), along with an indication of the reason for extending the incoming call (that is, for multiple-termination routing) in the DMH_RedirectionIndicator (“REDIND”) parameter. The TerminationList parameter includes a member list providing the plurality of potential terminating devices, and termination triggers that indicate when to request further instructions on call processing relating to each of the devices where call setups are being initiated. In this scenario the TerminationList parameter includes two terminations: an intersystem termination for the first member of the member list, and a PSTN termination for the second member of the member list.     408  After receiving the locreq at signaling step  407 , the Originating MSCe  48  initiates a call setup to each of the plurality of potential terminating devices (that is, mobile station  40  and the landline terminal  34 ). Upon analysis of the intersystem termination information, the Originating MSCe  48  determines that the intersystem termination is associated with an MSCe. Accordingly, the call setup uses SIP-T/SIP with the MSCe serving the termination device. The Originating MSCe  48  sends an INVITE message to the Serving MSCe  50  including Call-ID1, TLDN1 and SDP-4 to setup a call to the first member of the member list (that is, the mobile station  40 ). The INVITE may contain an encapsulated ISUP IAM message. Note that the Originating MSCe  48  may elect to modify SDP-4 from that received in signaling step  401 . Note that this INVITE request is for the establishment of a Dialog between the Originating MSCe  48  and the Serving MSCe  50  and is a different Dialog than that related to the INVITE request (see signaling step  401 ) received by the Originating MSCe  48 . The dialog between Originating MSCe  48  and the Serving MSCe  50  for a call setup to mobile station  40  is identified by Call-ID1. The Serving MSCe  50  will use TDLN1 to make the association with MSID1 received in the ROUTREQ message of signaling step  404  (see  FIG. 11 ).     409  After receiving the locreq at signaling step  407 , the Originating MSCe  48  establishes a context with the MGW  27 .
       Note that the reason the Originating MSCe  48  establishes a context with the MGW  27  is because the TerminationList parameter received in signaling step  407  included a PSTN termination, and the Originating MSCe  48  determined that ISUP must be used for the call setup. If the Originating MSCe  48  had determined that SIP could have been used for the call setup then there would be no requirement to have bearer resources allocated in MGW  27  for this termination.   The H.248 message sent from the Originating MSCe  48  to the MGW  27  includes two ADD commands. The first ADD command establishes termination  8  for a bearer channel using RTP towards the packet network  22 . The first ADD command includes a SDP-4, which is the remote SDP including the connection information for the bearer entity supporting the calling party (for example MGW  20  supporting a call initiated by mobile station  12 ). Connection information may include an IP Address and a User Datagram Protocol (“UDP”) Port number.   The first ADD command may also contain a BT (Bearer Timer) parameter indicating, in seconds, the length of time MGW  27  waits without receiving data from the connection endpoint defined in SDP-4 before applying an error treatment to termination  8  (for example removing termination  8  from the bearer channel using RTP towards the packet network  22  and sending a message to the Originating MSCe  48  informing it of the action). The Originating MSCe  48 , from the TERMLIST parameter in the locreq message (signaling step  407 ), is aware that the call setup is one termination of a multiple-termination routing scenario. In general the call setup time of a multiple-termination routing scenario is greater than the call setup time of a single termination scenario. The Originating MSCe  50  may, on a per call setup basis, adjust the value of BT based on knowledge it may have about the call setup.   The second ADD command establishes termination  9  for a PSTN communication channel (for example, DS0 on a T1 or E1 line) with a mode set to recvonly (or sendrecv).   
         410  The MGW  27  replies to the H.248 message of signaling step  409 , by sending the Serving MSCe  50  a H.248 Replay message. The H.248 Reply message includes SDP-8, the local SDP for the MGW  27 . SDP-8 includes connection information, such as an IP address, a UDP Port number, and a list of Codecs that the MGW  27  supports for sending and receiving.     411  The Originating MSCe  48  sends an ISUP IAM to setup a call to the second member of the member list (that is, the PSTN directory number corresponding to the landline terminal  34 ).     412  After receiving the locreq in signaling step  407 , if the INVITE request of signaling step  401  did not contain an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message to the originator of the INVITE request (signaling step  401 ).
       When the INVITE request in signaling step  401  includes an ISUP IAM Message, the Originating MSCe  48  may send either a 180 Ringing message or a 183 Session Progress message including an ISUP ACM (Address Complete Message) message to the originator of the INVITE request at signaling step  401 .   If the Originating MSCe  48  elects to initiate local ringback, then a 180 Ringing message is sent; otherwise a 183 Session Progress message is sent. For a call setup to a single terminating device the MSCe (or the serving exchange for a landline terminal device) that is serving the terminating device controls all aspects of ringback to the calling party. When multiple-termination routing is performed the control logic within Originating MSCe  48  controls all aspects of ringback to the calling party. Accordingly, in this message exchange, when the call delivery request of signaling step  401  is a SIP INVITE, the Originating MSCe  48  may respond to the received call delivery request with a ringback message that instructs the sender of the call delivery request to generate ringback to the calling party terminating device.   
         413  In response to the 180 Ringing or 183 Session Progress message, a PRACK message is sent to the Originating MSCe  48 .     414  The Originating MSCe  48  sends a 200 OK response to the PRACK message (signaling step  413 ).     415 - 17  The ringing management between the originating MSCe  48  and the Serving MSCe  50  prevents the Serving MSCe  48  from controlling local ringback to the calling party. Ringing management  415 - 17  will be discussed in detail with reference to  FIG. 12 .     418  The Originating MSCe  48  receives an ISUP ACM associated with the PSTN call setup to landline terminal  34 .     419  After receiving an INVITE message in signaling step  408 , the Serving MSCe  50  sends a PAGING REQUEST message to initiate a mobile terminated call setup scenario for the mobile station associated with TLDN1 (that is, mobile station  40 ). The PAGING REQUEST message includes the “Desired Codec” for the mobile station  40 .     420  When the terminating mobile station responds to the page, a PAGING RESPONSE message is sent from the base station  36  to the Serving MSCe  50 . The PAGING RESPONSE message includes the codec chosen by the mobile station  40 . The PAGING RESPONSE message may contain a list of available BS transcoders, and the connection information for the base station  36  communications channel at termination  7 .     421  The Serving MSCe  50  establishes a context with a MGW  26 . The H.248 message sent from the Serving MSCe  50  to the MGW  26  includes of two ADD commands. The first ADD command establishes a termination for a bearer channel using RTP towards the packet network  22 . The mode is set to sendrecv. If the Serving MSCe  50  elects to initiate Termination-Side ringback, then ringback from termination  5  is initiated. SDP-4 is the remote SDP including the connection information for the bearer entity supporting the calling party (for example MGW  20  supporting a call initiated by mobile station  12 ), Connection information may include an IP Address and a User Datagram Protocol (“UDP”) Port number).
       Note that any ringback tone generated by the MGW  26  will not be received by the calling party. As mentioned with respect to signaling step  412  the Originating MSCe  48  controls all aspects of ringback to the calling party for multiple-termination routing scenarios. The bearer entity supporting the calling party will not allow received data to be passed to the calling party until the bearer entity is assured that the data is coming from a trusted source. The Originating MSCe  48  controls the flow of all messaging to the network entities support the calling party. It is only when the Originating MSCe  48  sends a  200  OK (INVITE) including a SDP (with the connection information of the trusted source) that is in response to the SIP INVITE of signaling step  201  will the bearer entity supporting the calling party will allow received bearer data to be passed to the calling party. The second ADD command establishes a termination for the base station  36  communication channel with a mode set to sendrecv. The second ADD command includes SDP-7, which is the remote SDP including the base station connection information (that is, information sent in signaling step  420  that relates to termination  7 ).   The first ADD command may also contain a BT (Bearer Timer) parameter indicating, in seconds, the length of time MGW  26  waits without receiving data from the connection endpoint defined in SDP-4 before applying an error treatment to termination  5  (for example removing termination  5  from the bearer channel using RTP towards the packet network  22  and sending a message to the Serving MSCe  50  informing it of the action). The Serving MSCe  50 , from the LEGINFO1 parameter in the Routereq message (signaling step  404 ), is aware that the call associated with TLDN1 is one termination of a multiple-termination routing scenario. In general the call setup time of a multiple-termination routing scenario is greater than the call setup time of a single termination scenario. The Serving MSCe  50  may, on a per call setup basis, adjust the value of BT based on knowledge it may have about the call setup.   
         422  The MGW  26  replies to the H.248 message of signaling step  421  by sending the Serving MSCe  50  an H.248 Reply message. The Reply message includes SDP-5 and SDP-6. SDP-5 is the local SDP for the termination (identified by the connection information) given in SDP 4, and includes the MGW  26  connection information for termination  5 . SDP-6 is the local SDP for the termination towards the base station  36  and includes the connection information (for example, IP address and UDP Port number) for termination  6 .     423 - 25  The session progress signaling addresses the handshake operation between the Serving MSCe  50  and the Originating MSCe  48 . The session progress interaction of the Originating MSCe  48  with the Serving MSCe  50  operates to provide connection management for the call setups. The session progress signaling  423 - 25  will be discussed in detail with reference to  FIG. 13 .     426  After receiving the Reply message at signaling step  422 , the Serving MSCe  50  sends an IOS Assignment Request message to the base station  36  to request assignment of radio resources. The Assignment Request message includes the MGW  26  connection information (for termination  6 , obtained from signaling step  422 ), request of any base station transcoding (if necessary) and the codec assignment for the mobile station  40  associated with TDLN1.     427  After receiving an IOS Assignment Request message at signaling step  427 , the base station  36  sends the IOS Assignment Complete message to the Serving MSCe  50 .     428  The base station  36  sends a CONNECT message to the Serving MSCe  50  to indicate that the call has been answered by the mobile station associated with TLDN1 (that is, mobile station  40 ).     429  If the Serving MSCe  50  elected to initiate Termination-Side ringback (in signaling step  421 ), then the Serving MSCe  50  will send a H.248 message to MGW  26 . The H.248 message includes a MODIFY command to deactivate Termination-Side Ringback.     430  The MGW  26  acknowledges the H.248 message of signaling step  429  with a H.248 Reply message sent from MGW  26  to Serving MSCe  50 .     431  After receiving the CONNECT message from the base station  36  and the PRACK message (see  FIG. 13 , signaling step  424 ) is received, the Serving MSCe  50  sends a 200 OK message to the Originating MSCe  48 . When the INVITE request at signaling step  408  includes an ISUP IAM Message, then the 200 OK message may contain an ISUP ANM (Answer Message) message. The 200 OK message acknowledges that the INVITE message from signaling step  408  has succeeded. In this manner, the Originating MSCe  48  detects a first potential terminating device to complete the initiated call setup.     432  Upon receiving a 200 OK message or an ISUP ANM message from any one of the call setup requests (for example, from the INVITE message of signaling step  408  or the ISUP IAM in signaling step  411 ) the Originating MSCe  48  sends a 200 OK message to the originator of the INVITE request of signaling step  401 . Since the intersystem termination (that is, the mobile station  40 ) answered first, the 200 OK message includes SDP-5 (that is, the SDP received in signaling step  423 ). When the INVITE request from signaling step  401  includes an ISUP IAM message, then the 200 OK message may contain an ISUP ANM message. The 200 OK message acknowledges that the INVITE request from signaling step  401  message succeeded.
       Note that if the PSTN termination answered first, then the 200 OK message would contain the SDP-8 received in signaling step  410 .   
         433  The Originating MSCe  48  receives an ACK message. The ACK message confirms reception of the final response (that is, the 200 OK from signaling step  432 ) for the Dialog identified by Call-ID0.     434  Upon receiving an ACK message in signaling step  433 , the Originating MSCe  48  sends an ACK message to the Serving MSCe  50  to confirm reception of the final response (that is, the 200 OK from signaling step  431 ) for the Dialog identified by Call-ID1.     435 - 38  Upon detecting a first potential terminating device to complete the call setup, any call setups to remaining potential terminating device or devices are released. The release signaling steps  435 - 38  will be discussed in detail with reference to  FIG. 14 .   

       FIG. 11  is a signal flow diagram illustrating retrieve call features of  FIG. 10 :
       403 - 04  The HLR  52  recognizes the called number as a member of a multiple-termination routing and that, based on the received TransactionCapability parameter the Originating MSCe  48 , is capable of supporting a multiple-termination routing to a plurality of potential terminating devices. In this case, the first member in the member list (that is, the mobile station  40 ) is registered in another system; therefore, a ROUTREQ is sent to the visitor location register  54 , which forwards the ROUTREQ to the Serving MSCe  50 .     405 - 06  In response to the ROUTREQ, the Serving MSCe  50  checks its internal data structures and determines that the mobile station  40  is currently idle (or in similar call-ready states, such as the call is involved in another call, but has a call waiting feature). The Serving MSCe  50  allocates a TLDN and returns this information to the visitor location register  54  in a routreq response. The VLR  54  sends the routreq to the home location register  52 .   

       FIG. 12  is a signal flow diagram illustrating the ringing management signal sequence of  FIG. 10 . In this sequence of steps, the Originating MSCe  48  receives a SIP provisional response, indicating that the call setup to mobile station  40  is proceeding, from Serving MSCe  50  and acknowledges the reception with a SIP PRACK. Unlike a single termination scenario, when the Originating MSCe  48  receives any 18x messages from Serving MSCe  50  (such as for indicating a desire for local ringback), the 18x message is terminated (that is not forwarded onward to the packet network  22 ) by the Originating MSCe  48 .
       415  After receiving the INVITE of signaling step  408 , if the INVITE request did not contain an ISUP IAM Message, the Serving MSCe  50  can send either a 180 Ringing message or a 183 Session Progress message to the Originating MSCe  48 .
       When the INVITE request includes an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message including an ISUP ACM message to the Originating MSCe  48 .   If the Serving MSCe elects to initiate local ringback then the 180 Ringing message is sent.   
         416  In response to the 180 Ringing message or a 183 Session Progress message of signaling step  415 , a PRACK message is sent from the Originating MSCe  48  to the Serving MSCe  50 .     417  The Serving MSCe  50  sends a 200 OK response to the Originating MSCe  48  in response to the PRACK message of signaling step  416 .   

       FIG. 13  is a signal flow diagram illustrating the detailed session progress signal sequence of  FIG. 10  for connection management. In this sequence of steps, the Originating MSCe  48  receives a SIP provisional response from Serving MSCe  50 , indicating that the call setups to mobile station  40  is proceeding, and also acknowledging the Serving MSCe  50  reception of the SIP PRACK message. Unlike a single termination scenario, the Originating MSCe will store any information received (such as SDP messages) in the SIP provisional response and does not act. Only when the Originating MSCe  50  receives information as to which of the terminating devices completes the call setup (signaling step  431  which includes Call-ID1) does the Originating MSCe  50  retrieve the appropriate stored information and send it to the signaling entity supporting the calling party.
       423  Upon receiving a Reply message in signaling step  422 , the Serving MSCe  50  sends the Originating MSCe  48  a 183 Session Progress message including SDP-5.
       Note the 183 Session Progress message is not sent to the originator of the INVITE message, signaling step  401 .   
         424  In response to the 183 Session Progress message of signaling step  423 , the Originating MSCe  48  stores SDP-5, and sends a PRACK message to the Serving MSCe  50 .     425  The Serving MSCe  50  sends a response to the PRACK message of signaling step  424  to the Originating MSCe  48 .   

       FIG. 14  is a signal flow diagram illustrating the release of the call setups to the remaining potential terminating devices of  FIG. 10 :
       435  Upon receiving a 200 OK message (signaling step  431 ), the Originating MSCe  48  sends an ISUP REL (Release) message to release the PSTN call setup.     436  The Originating MSCe  48  receives an ISUP RLC (Release Complete) message signaling completion of the PSTN call setup release.     437  Upon receiving a 200 OK message in signaling step  431 , the Originating MSCe  48  sends the MGW  27  an H.248 message. The H.248 message includes two SUBTRACT commands to remove termination  8  and termination  9 .     438  The MGW  27  replies to the H.248 message of signaling step  437  with a Reply message.   

       FIGS. 15   a  and  15   b  are a signal flow diagram  500  illustrating call delivery for consecutive multiple-termination routing. The example provides two multiple-terminations: the mobile station  40  via the base station  36 , and the mobile station  46  via the mobile station  42 .
       501  The Originating MSCe  48  receives an INVITE message including a SDP message labeled SDP-4 and a called number. The INVITE may contain an encapsulated ISUP IAM. The Originating MSCe  48  is the MSCe that owns the called number dialing by the calling party (for example mobile station  12 ).     502  The Originating MSCe  48  sends a LOCREQ to the home location register  52  associated with the called number. The Originating MSCe  48  may optionally include the TransactionCapability parameter to specify the appropriate termination handling.     503 - 06  The call features associated with the called number are retrieved via the home location register  52 . Retrieval of the call features will be discussed in detail with reference to  FIG. 16 .     507  When the routreqs are received by the home location register  52  from signaling steps  503 - 06 , the HLR  52  returns a locreq to the Originating MSCe  48 . The locreq includes termination routing information for the first group member in the form of the TerminationList parameter, along with an indication of the reason for extending the incoming call (that is, for multiple-termination routing) in the DMH_RedirectionIndicator (“REDIND”) parameter. In this scenario the TerminationList member list includes an intersystem termination for the first member, mobile station  40 . The NATIME (No Answer TIME) parameter indicates, in seconds, the length of time the Originating MSCe  48  waits before applying a no-answer treatment to the call setup.     508  After receiving the locreq from signaling step  507 , the Originating MSCe  48  determines that the intersystem termination is associated with an MSCe and thus SIP-T/SIP will be used for the call setup to the MSCe serving the termination device. The Originating MSCe  48  sends an INVITE message to the Serving MSCe  50  including Call-ID1, TLDN1 and SDP-4 to setup a call to the member in the multiple-termination member list (that is, the mobile station  40 ). The INVITE can contain an encapsulated ISUP IAM message. Note that the Originating MSCe  48  can elect to modify SDP-4 as received in signaling step  501 . Note that the INVITE request of this signaling step is for the establishment of a Dialog between the Originating MSCe  48  and the Serving MSCe  50 , and is a different Dialog than that related to the INVITE request of signaling step  501  received by the Originating MSCe  48 . The Serving MSCe  50  will use TDLN1 to make the association with MSID1 received in the ROUTREQ message of signaling step  504  (see  FIG. 16 ).     509  After receiving the locreq in signaling step  507 , if the INVITE request of signaling step  501  did not contain an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message to the originator of the INVITE request (Step  1 ).
       When the INVITE request (Step  501 ) includes an ISUP IAM Message the Originating MSCe  48  may send either a 180 Ringing message or a 183 Session Progress message including an ISUP ACM message to the originator of the INVITE request of signaling step  501 .   If the Originating MSCe  48  elects to initiate local ringback, then a 180 Ringing message is sent. Otherwise, a 183 Session Progress message is sent. For a call setup to a single terminating device, the Serving MSCe that serves the terminating device controls all aspects of ringback to the calling party. When multiple-termination routing is performed, the control logic within the Originating MSCe  48  controls all aspects of ringback to the calling party. Accordingly, in this messaging exchange, when the call delivery request of signaling step  501  is a SIP INVITE, the Originating MSCe  48  may respond to the received call delivery request with a ringback message that instructs the sender of the call delivery request to generate ringback to the calling party terminating device.   
         510  In response to the 180 Ringing or 183 Session Progress message, a PRACK message is sent to the Originating MSCe  48 .     511  The Originating MSCe  48  sends a 200 OK response to the PRACK message of signaling step  510 .     512 - 14  The ringing management between the Originating MSCe  48  and the Serving MSCe  50  prevents the Serving MSCe from controlling local ringback to the calling party. Ringing management  512 - 14  will be discussed in detail with reference to  FIG. 17 .     515  After receiving the INVITE message in signaling step  508 , the Serving MSCe  50  sends an MS PAGING REQUEST message to the base station  36  to initiate a mobile terminated call setup scenario for the mobile station associated with TLDN1 (that is, mobile station  40 ). The PAGING REQUEST message includes the “Desired Codec” for the mobile station  40 .     516 - 20  When the terminating mobile station  40  responds to the page, an IOS PAGING RESPONSE message is sent from the base station  36  to the Serving MSCe  50 . The PAGING RESPONSE message includes the codec chosen by the mobile station  40 . The PAGING RESPONSE message may contain a list of available base station  36  transcoders, and the connection information for the base station communications channel at termination  7 .     521  The Serving MSCe  50  establishes a context with a MGW  26 . An H.248 message is sent from the Serving MSCe  50  to the MGW  26 , and for this example, includes two ADD commands. The first ADD command establishes a termination for a bearer channel using RTP towards the packet network  22 . The mode is set to sendrecv. If the Serving MSCe  50  elects to initiate Termination-Side ringback, then the MGW  26  initiates ringback from termination  5 . The first ADD command includes SDP-4, which is the remote SDP including the connection information for the bearer entity supporting the calling party (for example, the MGW  20  supporting a call initiated by the mobile station  12 ). Connection information may include an IP Address and/or a User Datagram Protocol (“UDP”) port number. Note that the ringback tone generated by the MGW  26  is not sent to the calling party. As mentioned in signaling step  509  the originating MSCe  48  controls all aspects of ringback to the calling party for multiple-termination routing scenarios. The bearer entity supporting the calling party will not allow such data to pass to the calling party until the bearer entity confirms that the data comes from a trusted source (such as a first responding device). In this manner, erroneous noise or sound transmission to the calling party is avoided. The Originating MSCe  48  controls the flow of the messaging to the network entities that support the calling party. Upon the Originating MSCe  48  response to the SIP INVITE of signaling step  501  with a 200 OK (INVITE) having an SDP (and the associated connection information of the trusted source), then the bearer entity supporting the calling party passes the received bearer data to the calling party.
       The first ADD command may also contain a BT (Bearer Timer) parameter indicating, in seconds, the length of time MGW  26  waits without receiving data from the connection endpoint defined in SDP-4 before applying an error treatment to termination  5  (for example removing termination  5  from the bearer channel using RTP towards the packet network  22  and sending a message to the Serving MSCe  50  informing it of the action). The Serving MSCe  50 , from the LEGINFO1 parameter in the Routereq message (signaling step  504 ), is aware that the call associated with TLDN1 is one termination of a multiple-termination routing scenario. In general the call setup time of a multiple-termination routing scenario is greater than the call setup time of a single termination scenario. The Serving MSCe  50  may, on a per call setup basis, adjust the value of BT based on knowledge it may have about the call setup.   The second ADD command establishes a termination for the base station  36  communication channel with a mode set to sendrecv. The second ADD command includes SDP-7, which is the remote SDP including the base station  36  connection information (that is information sent in signaling step  512  that relates to termination  7 ).   
         522  The MGW  26  replies to the H.248 message by sending a H.248 Reply message to Serving MSCe  50 . The Reply message includes SDP-5 and SDP-6. SDP-5 is the local SDP for the termination given in SDP 4 and includes the MGW  26  connection information for termination  5 . SDP-6 is the local SDP for the termination towards the base station  36  and includes the MGW  26  connection information (for example, IP address and UDP Port number) for termination  6 .     523 - 26  The session progress signaling addresses the handshake operation between the Serving MSCe  50  and the Originating MSCe  48 . The handshake operation between the Originating MSCe  48  and the Serving MSCe  50  operates to provide connection management for the call setup. The session progress signaling  523 - 26  will be discussed in detail with reference to  FIG. 18 .     526 - 27  After receiving the H.248 Reply message of signaling step  522 , the Serving MSCe  50  sends an IOS Assignment Request message to the base station  36  to request assignment of radio resources. The Assignment Request message includes the MGW  26  connection information (for termination  6 , obtained from signaling step  522 ), request for base station  36  transcoding (if necessary) and the codec assignment for the mobile station associated with TDLN1.
       After receiving an Assignment Request message in signaling step  526 , the base station  36  sends an IOS Assignment Complete message to the Serving MSCe  50 .   
         528 - 34  After the time value of NATIME in signaling step  507  has been exceeded, the call setup is released. Details of the release in signaling steps  528 - 34  will be discussed in detail with reference to  FIG. 19 .     535  Following a non-completion of the initiated call setup to the first of the plurality of potential terminating devices (in this example, the mobile station  40 ), the Originating MSCe  48 , based upon the instructions in the TERMTRIG (Termination Triggers) parameter of signaling step  507  sends a TRANUMREQ to the home location register  52 . The TRANUMREQ contains a REDREASON (RedirectionReason) parameter and the BILLID (Billing ID) associated with the first call setup. The Originating MSCe  48  may optionally include a TRANSCAP (TransactionCapability) parameter to indicate the Originating MSCe  50  transaction capability at the current time.     536 - 39  The next call features associated with the called number with respect to consecutively initiated call setups for the remaining potential terminating devices are retrieved next via the home location register  52 . Retrieval of the call features for signaling steps  536 - 39  will be discussed in detail with reference to  FIG. 20 .     540  When the routreq is received by the home location register  52  in signaling steps  536 - 39 , the HLR  52  returns a tranumreq to the Originating MSCe  48 . The tranumreq includes multiple-termination routing information in the form of the TerminationList parameter, along with an indication of the reason for extending the incoming call (that is, for consecutively initiated multiple-termination routing) in the REDIND (DMH_RedirectionIndicator) parameter. In this scenario the TerminationList parameter includes the next termination for consecutively initiating terminations (that is, mobile station  46 ).     541  After receiving the tranumreq response from signaling step  540 , the Originating MSCe  48  determines that the intersystem termination is associated with a MSCe, and that SIP-T/SIP is used for the call setup to the MSCe serving the termination device. The Originating MSCe  48  sends to the Serving MSCe an INVITE message that includes Call-ID2, TLDN2 and SDP-4 to setup a call to the second member of the member list (that is, the mobile station  46 ). The INVITE can include an encapsulated ISUP IAM message. Note that the Originating MSCe  48  can elect to modify SDP-4 as received in signaling step  501 . Also, the INVITE request for this signaling step establishes a Dialog between the Originating MSCe  48  and the Serving MSCe  50 , and is a different Dialog than that related to the INVITE request of signaling step  501 , received by the Originating MSCe  48 . The Serving MSCe  50  uses TDLN2 to make the association with MSID2 received in the ROUTREQ message of signaling step  537 .     545 - 47  The ringing management between the Originating MSCe  48  and the Serving MSCe  50  prevents the Serving MSCe from controlling local ringback to the calling party. Ringing management  545 - 47  will be discussed in detail with reference to  FIG. 21 .     548  After receiving an INVITE message in signaling step  541 , the Serving MSCe  50  sends to the base station  42  an IOS PAGING REQUEST, which initiates a mobile terminated call setup scenario for the mobile station associated with TLDN2 (that is, mobile station  46 ). The PAGING REQUEST message includes the “Desired Codec” for mobile station  46       549  When the mobile station  46  responds to the page, an IOS PAGING RESPONSE message is sent from the base station  42  to the Serving MSCe  50 . The PAGING RESPONSE message includes the codec chosen by the terminating mobile. The PAGING RESPONSE message may contain a list of available base station transcoders, and the connection information for the base station  42  communications channel at termination  11 .     555  The Serving MSCe  50  establishes a context with a MGW  27 . An H.248 message is sent from Serving MSCe  50  to the MGW  27  including two ADD commands. The first ADD command establishes a termination for a bearer channel using RTP towards the packet network  22 . The mode is set to sendrecv. If the Serving MSCe  50  elects to initiate Termination-Side ringback, the MGW  27  initiates ringback from termination  9 . The first ADD command includes SDP-4, which is the remote SDP including the connection information for the bearer entity supporting the calling party (for example MGW  20  supporting a call initiated by mobile station  12 ). Connection information may include an IP Address and a User Datagram Protocol (“UDP”) Port number.
       Note that the MGW  26  generates a ringback tone that will not be received by the calling party. As mentioned in step  509  the Originating MSCe  48  controls all aspects of ringback to the calling party for multiple-termination routing scenarios. The bearer entity supporting the calling party will not allow received data to be passed to the calling party until the bearer entity is assured that the data is coming from a trusted source (such as a first responding terminal). The Originating MSCe  48  controls the flow of all messaging to the network entities support the calling party. As an example of a trusted source, the bearer entity that supports the calling party passes received bearer data (such as voice/sound data) to the calling party when a 200 OK (INVITE) including a SDP (with the connection information of the trusted source) sent by the Originating MSCe  48  in response to the SIP INVITE of signaling step  501 .   The first ADD command may also contain a BT (Bearer Timer) parameter indicating, in seconds, the length of time MGW  27  waits without receiving data from the connection endpoint defined in SDP-4 before applying an error treatment to termination  9  (for example removing termination  9  from the bearer channel using RTP towards the packet network  22  and sending a message to the Serving MSCe  50  informing it of the action). The Serving MSCe  50 , from the LEGINFO2 parameter in the Routereq message (signaling step  537 ), is aware that the call associated with TLDN2 is one termination of a multiple-termination routing scenario. In general the call setup time of a multiple-termination routing scenario is greater than the call setup time of a single termination scenario. The Serving MSCe  50  may, on a per call setup basis, adjust the value of BT based on knowledge it may have about the call setup.   The second ADD command establishes a termination for the base station  42  communication channel with a mode set to sendrecv. The second ADD command includes SDP-7, which is the remote SDP including the base station  42  connection information (that is, information sent in signaling step  547  that relates to termination  11 ).   
         556  The MGW  27  replies to the H.248 message by sending a H.248 Reply message to Serving MSCe  50 . The Reply message includes SDP-9 and SDP-10. SDP-9 is the local SDP for the termination given in SDP-4 and includes the MGW  27  connection information for termination  9 . SDP-10 is the local SDP for the termination towards the base station  42  and includes the MGW  27  connection information (for example, IP address and UDP Port number) for termination  10 .     557 - 59  The session progress signaling addresses the handshake operation between the Serving MSCe  50  and the Originating MSCe  48 , which provides connection management for the call setup. The session progress signaling  557 - 59  will be discussed in detail with reference to  FIG. 22 .     560 - 61  After receiving the H.248 Reply message of signaling step  556 , the Serving MSCe  50  sends an IOS Assignment Request message to the base station  42  to request assignment of radio resources. The IOS Assignment Request message includes the MGW  27  connection information (for termination  10 , obtained from signaling step  556 ), request of any base station  42  transcoding (if necessary) and the codec assignment for the mobile station associated with TDLN2.
       After receiving an IOS Assignment Request message from signaling step  560 , the base station  42  sends an IOS Assignment Complete message to the Serving MSCe  50 .   
         562  The base station  42  sends an IOS CONNECT message to the Serving MSCe  50  to indicate that the call has been answered by the mobile station associated with TLDN2 (that is, mobile station  46 ).     563  If the Serving MSCe  50  elected in signaling step  555  to initiate Termination-Side ringback, then the Serving MSCe  50  sends a H.248 message to MGW  27 . The H.248 message contains a MODIFY command to deactivate Termination-Side Ringback.     564  MGW  27  acknowledges the H.248 message of signaling step  562  by sending a H.248 Reply message to Serving MSCe  50 .     565  After receiving the CONNECT message from the base station  42  and the PRACK message is received in signaling step  558  (see  FIG. 22 ), the Serving MSCe  50  sends a 200 OK message to the Originating MSCe  48 . When the INVITE request of signaling step  541  includes an ISUP IAM Message, then the 200 OK message can contain an ISUP ANM message. The 200 OK (INVITE) message acknowledges that the INVITE of signaling step  541  has succeeded.     566  Upon receiving a 200 OK message in signaling step  565 , the Originating MSCe  48  sends a 200 OK message to the originator of the INVITE request of signaling step  501 . Since the intersystem termination (that is, the mobile station  46 ) first answered and/or responded, the 200 OK message includes SDP-9 (that is the SDP received in signaling step  556 ). When the INVITE request of signaling step  501  includes an ISUP IAM message, then the 200 OK message can contain an ISUP ANM Message. The 200 OK message acknowledges that the INVITE of signaling step  501  message has succeeded.     567  The Originating MSCe  48  receives an ACK message. The ACK message confirms reception of the final response (that is, the 200 OK message of signaling step  566 ) for the Dialog identified by Call-ID0.     566  Upon receiving an ACK message in signaling step  567  for the Dialog identified by Call-ID0, the Originating MSCe  48  sends an ACK message to the Serving MSCe  50  to confirm reception of the final response (that is, 200 OK message of signaling step  566 ) for the Dialog identified by Call-ID2.   

       FIG. 16  is a signal flow diagram illustrating the retrieve call features signal sequence of  FIG. 15   a:  
       503 - 04  The HLR  52  recognizes the called number as a member of a multiple-termination routing and that, based on the received TransactionCapability parameter the Originating MSCe  48 , is capable of supporting a multiple-termination routing to a plurality of potential terminating devices. In this case, the first member in the member list (that is, the mobile station  40 ) is registered in another system; therefore, a ROUTREQ is sent to the VLR  54 , which forwards the ROUTREQ to the Serving MSCe  50 .     505 - 06  In response to the ROUTREQ, the Serving MSCe  50  checks its internal data structures and determines that the mobile station  40  is currently idle (or in similar call-ready states, such as the call is involved in another call, but has a call waiting feature). The Serving MSCe  50  allocates a TLDN and returns this information to the VLR  54  in a routreq response. The VLR  54  sends a routreq to the HLR  52 .   

       FIG. 17  is a signal flow diagram illustrating the ringing management signal sequence of  FIG. 15   a:  
       512  After receiving the INVITE of signaling step  508 , if the INVITE request did not contain an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message to the Originating MSCe  48 
       When the INVITE request includes an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message including an ISUP ACM message to the Originating MSCe  48 .   If the Serving MSCe elects to initiate local ringback then the 180 Ringing message is sent.   
         513  In response to the 180 Ringing message or a 183 Session Progress message of signaling step  512 , a PRACK message is sent from the Originating MSCe  48  to the Serving MSCe  50 .     514  The Serving MSCe  50  sends a 200 OK response to the Originating MSCe  48  in response to the PRACK message of signaling step  513 .   

       FIG. 18  is a signal flow diagram illustrating the detailed session progress signal sequence of  FIG. 15   a:  
       523  Upon receiving a H.248 Reply message to the ADD message in signaling step  522 , the Serving MSCe  50  sends the Originating MSCe  48  a 183 Session Progress message including SDP-5.
       Note the 183 Session Progress message is not sent to the originator of the INVITE message, signaling step  501 .   
         524  In response to the 183 Session Progress message of signaling step  523 , the Originating MSCe  48  stores SDP-5, and sends a PRACK message to the Serving MSCe  50 .     525  The Serving MSCe  50  sends a response to the PRACK message of signaling step  524  to the Originating MSCe  48 .   

       FIG. 19  is a signal sequence illustrating releasing the call setup of a potential terminating-device of  FIG. 15   a:  
       528  Following the passage of a time period given by the NATIME parameter of signaling step  507 , the Originating MSCe  48  abandons the call setup attempt with mobile station  40 . The Originating MSCe  48  sends a IOS CANCEL message to the Serving MSCe  50 . When the INVITE request of signaling step  508  included an ISUP IAM Message then the CANCEL message may contain a ISUP REL message.     529  The Serving MSCe  50  sends a 487 Request Terminated message to the Originating MSCe  48 . The 487 Request Terminated message is a response to the INVITE request of signaling step  508 .     530  The Serving MSCe  50  answers the CANCEL request of signaling step  528  by sending a 200 OK message to the Originating MSCe  48 .     531  Upon receiving a CANCEL message of signaling step  528  from the Originating MSCe  48 , the Serving MSCe  50  starts releasing all resources associated with the call attempt to MSID-1 (that is, mobile station  40 ). The Serving MSCe  50  sends the MGW  26  a H.248 message consisting of two SUBTRACT commands. The first SUBTRACT command removes termination  6  to base station  36 . The second SUBTRACT removes termination  5  for the bearer channel using RTP towards the packet network  22 .     532  The MGW  26  replies to the H.248 message at signaling step  531  with a H.248 Reply message.     533  Upon receiving a CANCEL message at signaling step  528  from the Originating MSCe  48 , the Serving MSCe  50  sends an IOS Clear Command to base station  36 , instructing the base station  36  to release the associated dedicated resources.     534  The base station  36  sends an IOS Clear Complete message to the Serving MSCe  50 . The Serving MSCe  50  releases the underlying transport connection.   

       FIG. 20  is a signal flow diagram illustrating the next call features retrieval of signaling steps  536 - 539  of  FIG. 15   b:  
       536 - 37  Upon receiving the TRANUMREQ from the Originating MSCe  48 , the HLR  52  recognizes the Billing ID or the PilotNumber (the called number for signaling step  501 ) to relate the request to the information provide in the locreq, signaling step  507 . The HLR  52  associates the PilotNumber to the multiple-termination routing feature, and that, based on the received TransactionCapability parameter, the Originating MSCe  48  is capable of supporting a multiple-termination call. In this case, the second MSID in the member list (that is, mobile station  46 ) is registered in the same network system as MSID2. A ROUTREQ is sent to the VLR  54 , which forwards the ROUTREQ to the Serving MSCe  50 .     538 - 39  In response to the ROUTREQ, the Serving MSCe  50  checks its internal data structures and determines that the mobile station  46  is currently idle (or in similar call-ready states, such as the call is involved in another call, but has a call waiting feature). The Serving MSCe  50  then allocates a TLDN2 and returns this information to the VLR  54  in a routreq. The VLR  54  sends a routreq to the home location register  52 .   

       FIG. 21  is a signal flow diagram illustrating the ringing management signal sequence of  FIG. 15   b:  
       545  After receiving the INVITE of signaling step  541 , if the INVITE request did not contain an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message to the Originating MSCe  48 .
       When the INVITE request includes an ISUP IAM Message, the Serving MSCe  50  may send either a 180 Ringing message or a 183 Session Progress message including an ISUP ACM message to the Originating MSCe  48 .   If the Serving MSCe elects to initiate local ringback then the 180 Ringing message is sent.   
         546  In response to the 180 Ringing message or a 183 Session Progress message of signaling step  512 , a PRACK message is sent from the Originating MSCe  48  to the Serving MSCe  50 .     547  The Serving MSCe  50  sends a 200 OK response to the Originating MSCe  48  in response to the PRACK message of signaling step  548 .   

       FIG. 22  is a signal flow diagram illustrating the detailed session progress signal sequence of  FIG. 15   b . The Originating MSCe  48  coordinates the multiple-termination routing for connection management. Generally, the signal flow of  FIG. 22  reflects that the Serving MSCe  50  seeks to move the ringback to the terminating end of a call. When the Serving MSCe  50  does not seek to move the ringback to the terminating end of a call, the Serving MSCe  50  provides a 180 Ringing message with alert information (to update the SDP and to indicate to continue ringing). 
     As one of ordinary skill in the art would appreciate, the SDP may also be updated at a later point (such as with the 200 OK (Invite) at signaling step  564 ). Note that even through the Serving MSCe  50  might seek to initiate termination-side ringback, the Originating MSCe  48  controls all aspects of ringback to the calling party for multiple-termination routing scenarios. The bearer entity supporting the calling party will not pass received data to the calling party until the bearer entity is assured that the data is coming from a trusted source. The Originating MSCe  48  controls the flow of all messaging to the network entities support the calling party. In the present example, the bearer entity will pass received bearer data to the calling party when the Originating MSCe  48  sends a 200 OK (INVITE) including a SDP (with the connection information of the trusted source) in response to the SIP INVITE of signaling step  501 .
       559  Upon receiving a H.248 Reply message to the ADD message in signaling step  556 , the Serving MSCe  50  sends the Originating MSCe  48  a 183 Session Progress message including SDP-9.     560  In response to the 183 Session Progress message of signaling step  559 , the Originating MSCe  48  stores SDP-9, and sends a PRACK message to the Serving MSCe  50 .     561  The Serving MSCe  50  sends a response to the PRACK message of signaling step  560  to the Originating MSCe  48 .   

       FIG. 23  is a flow diagram of a method  600  for multiple-termination routing in a wireless environment that includes an Internet Protocol (“IP”) core. Beginning at step  602 , a call delivery request is received. The call delivery request is based upon intelligent network protocols and includes a called number. In this regard, the call delivery request may be based on ISUP protocols (for example, from a PSTN network  32 ) or based on SIP protocols (for example, a SIP INVITE request from a packet network  22 ). 
     With the called number, associated call features are retrieved at step  604 . The call feature retrieval uses ANSI-41 protocols, such as with a LOCREQ (LocationRequest) invoke message, which returns an ANSI-41 location request response (“locreq”). Within the location request response are the call features associated with the called number. 
     At step  608 , a determination is made as to whether the call features include multiple-termination routing information to a plurality of potential terminating devices. The call features include multiple-termination routing information in the form of a parameter, such as a TERMLIST (TerminationList) parameter. The multiple-termination routing information provides a member list of the potential terminating devices, and information indicating when to request further instructions on call processing relating to the device of the plurality of potential terminating devices. 
     When the call features include multiple-termination routing information at step  610 , wherein at least one termination to be setup utilizes Session Initiation Protocol (“SIP”), call setups are initiated to each of the plurality of potential terminating devices. The multiple-termination routing information provides the manner and/or sequence for initiating the call setups. 
     For example, the initiation of the call setup to each of the plurality of potential terminating devices may be conducted consecutively. The received call setup provisional responses (for example, those including a session description protocol (SDP)) provides connection information used for establishing a bearer path (that is, a path for voice and/or data) for the call setup. Upon detection of a first potential terminating device to complete the call setup, initiation of subsequent call setups is foregone to any remaining potential terminating devices. 
     As another example, the initiation of the call setup to each of the plurality of potential terminating devices may be conducted concurrently. The received provisional responses (for example, those including a session description protocol (SDP)) for each call setup provides connection information used for establishing a bearer path (that is, a path for voice and/or data) for the call setup. Upon detection of a first potential terminating device to complete the call setup, call setups is to any of the remaining potential terminating devices is released. 
     The invention disclosed herein is susceptible to various modifications and alternative forms. Specific embodiments therefore have been shown by way of example in the drawings and detailed description. It should be understood, however, that the drawings and the detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the claims.

Metadata:
Filing Date: 20120618
Publication Date: 20131231
Grant Date: 20131231
Priority Date: 20050214
Inventors: BIENN MARVIN
BHARATIA JAYSHREE A.
STEPHENS GARY B.
Assignee: APPLE INC
CPC Classifications: [{"code": "H04Q3/005", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W4/16", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04Q3/005", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 46272931