Abstract:
Described are methods and apparatuses, for selectively terminated custom application in a telecommunications network. A Gateway Mobile Switching Center (GMSC) receives a request to initiate a call session to a subscriber device in a service area of a first Mobile Switching Center (MSC). The GMSC established a dialogue to implement the custom application on the subscriber device. The GMSC receives a message indicating that the subscriber device is moving from the first MSC to a second MSC. The GMSC analyzes a service key of the custom application to determine if the dialogue should be terminated and determines that the dialogue should be terminated so that the custom application is continued on the subscriber device.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates generally to computer-based methods and apparatuses, including computer program products, for a Gateway Mobile Switching Center (GMSC) to selectively terminate and initiate custom applications when Mobile Terminating Roaming Retry (MTRR) is supported by the GMSC. 
       BACKGROUND 
       [0002]    The Global System for Mobile Communications (GSM) is one or more networks that execute cell phone calls. GSM networks include various network elements that are used to complete a call. For example, GSM networks can include a Home Location Register (HLR), Mobile Switching Center (MSC), and Gateway Mobile Switching Center (GMSC). In addition to providing call connections, mobile provider networks provide Intelligent Network (IN) services to enhance service provided to customers. Video downloads, music downloads, prepaid service, automated call forwarding, and ring-back tone services are a few of such enhanced services. Enhanced services can be implemented using Customized Applications for Mobile Network Enhanced Logic (CAMEL) protocol. 
         [0003]    CAMEL protocol is a set of standards defined by European Telecommunication Standardization Institute (ETSI). Subsequently, Third Generation Partnership Project (3GPP) defined upgrades to the CAMEL protocol. CAMEL protocol enables service providers to continue to service their subscribers with enhanced services even when a subscriber is roaming outside of their home network. 
         [0004]    When a call is made to a subscriber&#39;s equipment (commonly referred to as user equipment (UE)), a GMSC establishes CAMEL Application Protocol (CAP) dialogues to supply services to the UE. Simultaneously, an MSC that is connected to the GMSC and servicing the UE pages the UE. When the UE moves from a location that is covered by the MSC to a location that is covered by a second MSC, the UE sends out a location update to the second MSC. Location update is described in 3GPP TS 23.018. 
         [0005]    If a first MSC receives a call to a UE while the UE is moving from a geographic location served by the first MSC to a geographic location served by the second MSC, the first MSC sends a paging message to the UE at the same time that the UE is in the process of a location update. Thus, the UE does not respond to the paging message and the first MSC can not establish the call. Mobile Terminating Roaming Retry Call (MTRR) has been implemented to address this problem. If MTRR is implemented on the GMSC, when the UE transmits a location update, the HLR transmits a cancel location message to the first MSC. The first MSC aborts paging the UE and transmits a Resume Call Handling (RCH) message to the GMSC. The RCH message indicates whether MTRR is requested for this call. 
         [0006]    When the GMSC receives a RCH message that indicates MTRR is requested, it terminates all ongoing CAP dialogues. After the location update is complete the GMSC reestablishes the CAP dialogues. Terminating and reestablishing the CAP dialogues can create an interruption in a subscriber&#39;s service. For example, if a caller&#39;s tune is being played to the calling party by a CAP dialogue, when the CAP dialogue is terminated the tune is stopped. When the CAP dialogue is terminated, the caller will no longer hear the tune and may hang up due to the lack of audio. Therefore, it is desirable to selectively terminate CAP dialogues, rather than terminate all CAP dialogues upon receipt of a RCH message by the GMSC when MTRR is enabled. 
       SUMMARY OF THE INVENTION 
       [0007]    In one aspect, the invention features a method of selectively terminating a custom application in a mobile telecommunications network. The method involves receiving, by a GMSC, a request to initiate a call session to a subscriber device in a service area of first MSC. The method also involves, establishing, by the GMSC, a dialogue to implement the custom application on the subscriber device. The method also involves receiving, by the GMSC, a message indicating that the subscriber device is moving from the first MSC to a second MSC and analyzing, by the GMSC, a service key of the custom application to determine if the dialogue should be terminated and the custom application ceased. The method also involves determining, by the GMSC, that the dialogue should not be terminated so that the custom application is continued on the subscriber device. 
         [0008]    In another aspect, the invention features a GMSC including a computing device configured to selectively terminate a custom application in a mobile telecommunications network. The computing device is operable to receive a request to initiate a call session to a subscriber device in a service area of a first MSC. The computing device is also operable to establish a dialogue to implement the custom application on the subscriber device and receive a message indicating that the subscriber device is moving from a first MSC to a second MSC. The computing device is also operable to analyze a service key of the custom application to determine if the dialogue should be terminated and the custom application ceased and determine that the dialogue should not be terminated so that the custom application is continued on the subscriber device. 
         [0009]    In another aspect, the invention features a GMSC including means for receiving a request to initiate a call session to a subscriber device in a service area of first MSC. The GMSC also includes means for establishing a dialogue to implement the custom application on the subscriber device and means for receiving a message indicating that the subscriber device can be handed off from a first MSC to a second MSC. The GMSC also includes means for analyzing a service key of the custom application to determine if the dialogue should be terminated and the custom application ceased and means for determining that the dialogue should not be terminated so that the custom application is implemented on the subscriber device. 
         [0010]    In other embodiments, any of the aspects, or any apparatus, device or system or method, process or technique described herein, can include one or more of the following features. 
         [0011]    In some embodiments, the mobile telecommunications network supports Mobile Terminating Roaming Retry. In some embodiments, the message indicating that the subscriber device is moving is a RCH message received from the first MSC. In some embodiments, the service key comprises a control action configured by a service provider to indicate that the custom application should not be terminated. In some embodiments, the dialogue is an application level dialogue. 
         [0012]    In some embodiments, the dialogue comprises a CAMEL application protocol. In some embodiments, the custom application is an intelligent network customized application. In some embodiments, the custom application comprises CAMEL. 
         [0013]    In some embodiments, the method involves continuously providing the custom application without interruption after the GMSC determines that the dialogue should not be terminated. In some embodiments, the service key is configured, by the GMSC, based on a type of the customized application. 
         [0014]    In some embodiments, the method involves receiving, by the GMSC, a request to establish the dialogue, analyzing, by the GMSC, a service key of the custom application to determine if the dialogue should be established, and determining, by the GMSC, that the dialogue should not be established. 
         [0015]    One advantage of the process is that subscriber services can be maintained while roaming. Another advantage of the process is that each service provider can either specify services it wants to terminate or maintain. 
         [0016]    Other aspects and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating the principles of the invention by way of example only. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The foregoing and other objects, features, and advantages of the invention, as well as the invention itself, will be more fully understood from the following description of various embodiments, when read together with the accompanying drawings. 
           [0018]      FIG. 1  is block diagram showing an exemplary GSM network. 
           [0019]      FIG. 2  is a sequence diagram of a GMSC terminating all CAP dialogues. 
           [0020]      FIG. 3  is sequence diagram of a GMSC selectively terminating CAP dialogues. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    In general overview, a GMSC receives a request to initiate a call to a UE. The GMSC establishes one or more CAP dialogues to implement custom applications on the UE. The UE is in the process of moving from a first MSC to a second MSC. The UE is transmitting a location update. The first MSC sends a RCH message to the GMSC. The RCH message includes an indicator that MTRR is applicable. The GMSC analyzes a service key of each CAP dialogue to selectively determine whether the CAP dialogue should be terminated or not. 
         [0022]      FIG. 1  is block diagram showing an exemplary GSM network  100  including UE  105 , a MSC  130 , an Equipment Identity Register (EIR)  140 , an Authorization Center (AUC)  150 , a HLR  160 , a GSM Service Control Function (gsmSCF)  155 , and a GMSC  170  that interfaces with other Public Land Mobile Networks (PLMN). The GMSC  170  can include a Service Switching Function (SSF) (not shown). The gsmSCF  155  and the SSF are two elements used with CAMEL protocol. The SSF stores CAMEL features that are unique to a particular carrier. The gsmSCF  155  contains call processing steps for the CAMEL services. Communication between GSM network elements is defined by the 3GPP to enable data, speech, and mobile network technology to converge over an Internet Protocol (IP) based infrastructure. One of ordinary skill in the art can appreciate that the GSM network can include other network elements not shown in  FIG. 1 . Exemplary CAMEL services include video downloads, music downloads, prepaid service, automated call forwarding, and ring-back tone services. 
         [0023]      FIG. 2  is a sequence diagram of a GMSC terminating all CAP dialogues. A GMSC  170  receives a request (not shown) to initiate a call session to a UE  105 . The GMSC  170  queries a HLR  160  for a temporary number (e.g., Mobile Subscriber Roaming Number (MSRN)) of the UE  105  by transmitting a Send Routing Information (SRI) message  206 . The SRI message includes a reference to the UE  105 , Call ref, and indicates that MTRR is supported. The HLR  160  returns an SRI acknowledgement (ACK) message  208  with Terminating CAMEL Subscription Information (T-CSI). The T-CSI identifies CAMEL services that are applicable to the UE  105 . The T-CSI includes service keys and a gsmSCF address where service logic that corresponds to the service keys reside. The GMSC  170  establishes CAP dialogues  210  with a gsmSCF  155 . 
         [0024]    The GMSC  170  queries the HLR  160  with a second request for the temporary number of the UE  105  by transmitting a SRI message  214 . The SRI message  214  indicates to the HLR  160  not to send a T-CSI in the SRI ACK with a suppress T-CSI indicator. The SRI message  214  indicates to the HLR  160  that MTRR is supported. The HLR  160  requests the temporary number from a first MSC  130  by transmitting a Provide Roaming Number (PRN) message  218 . The PRN message  218  includes the reference to the UE  105  and an indicator that MTRR is implemented. The first MSC  130  transmits a PRN ACK message  220  that includes the temporary number (MSRN) to the HLR  160 . The HLR  160  transmits an SRI ACK message  222  including the temporary number to the GMSC  170 . 
         [0025]    The GMSC  170  forwards an Integrated Service Digital Network (ISDN) User Part (ISUP) Initial Address Message (IAM) message  224  to the first MSC  130 . The IAM message  224  includes the MSRN. The first MSC  130  pages the UE  105  by transmitting a paging message  228  to the UE  105 . The UE  105  does not respond to the paging message  228  because the UE  105  has moved from a geographic location served by the first MSC  130  to a geographic location served by a second MSC  130 ′ during the call initiation request. The UE  105  transmits a location update message  232  to the second MSC  130 ′. The second MSC  130 ′ informs the HLR  160  that the UE  105  is within its service area by transmitting a location update message  236  to the HLR  160 . The HLR  160  informs the first MSC  130  that the UE  105  is no longer in the first MSC&#39;s  130  service area by transmitting cancel location message  238  to the first MSC  130 . The first MSC  130  transmits a cancel location ACK message  240  to the HLR  160 . The first MSC  130  stops paging the UE  105  and transmits a RCH message  246  to the GMSC  170 . The RCH message  246  includes the reference to the UE  105  and an indicator that MTRR is implemented. 
         [0026]    Upon receipt of the RCH message  246 , the GMSC  170  transmits an RCH ACK message  246  to the first MSC  130 . The GMSC  170  terminates all ongoing CAP dialogues  250 . The GMSC  170  releases the call request towards the first MSC  130  by transmitting a release (REL) message  252  to the first MSC  130 . The first MSC  130  releases the call request and transmits a release complete (RLC) message  254  to the GMSC  170 . 
         [0027]    The GMSC  170  transmits a new SRI message  260  to the HLR  160 . The new SRI message  260  does not contain a MTRR indicator. The HLR  160  holds the SRI response message  262  until the location update is complete. The HLR  160  transmits an update location ACK message  266  to the second MSC  130 ′. Subsequently, the HLR  160  transmits an SRI ACK message  268  including T-CSI to the GMSC  170 . 
         [0028]    The GMSC  170  reestablishes the CAP dialogues  270 . The GMSC  170  queries the HLR  160  with a second request for the temporary number of the UE  105  by transmitting a SRI message  272 . The SRI message  272  indicates to the HLR  160  not to send a T-CSI in the SRI ACK with a suppress T-CSI indicator. The HLR  160  requests the temporary number from the second MSC  130 ′ by transmitting a PRN message  274 . The second MSC  130 ′ transmits a PRN ACK message  276  that includes the temporary number (MSRN) to the HLR  160 . The HLR  160  transmits an SRI ACK message  278  including the temporary number to the GMSC  170 . 
         [0029]    The GMSC  170  forwards an ISUP IAM message  280  to the second MSC  130 ′. The ISUP IAM message  280  includes the MSRN. The second MSC  130 ′ pages the UE  105  by transmitting a paging message  282  to the UE  105 . The UE  105  transmits a paging response message  284  to the second MSC  130 ′. Call delivery is completed by typical call delivery procedures, according to 3GPP standards. 
         [0030]    As shown above, the GMSC  170  communicates with the two MSC&#39;s  130  and  130 ′ via the ISUP call control protocol. It is apparent to one of ordinary skill in the art that the GMSC  170  can communicate with the two MSC&#39;s via any call control protocol. For example, the call control protocol can be Bearer Independent Call Control or Session Initiation Protocol (SIP-I). 
         [0031]      FIG. 3  is a sequence diagram of a GMSC selectively terminating CAP dialogues. The transmission of messages or dialogues in  FIG. 3  is substantially the same as the transmission of messages or dialogues transmitted in  FIG. 2  until the receipt of the first RCH message  246  by the GMSC  170 . For clarity purposes, the message flow is not repeated here. 
         [0032]    Upon receipt of the RCH message  246 , the GMSC  170  transmits an RCH ACK message  248  to the first MSC  130 . The GMSC  170  determines whether each CAP dialogue should be terminated based on the service key of each CAP dialogue. The service key can include an associated control action that indicates whether or not the CAP dialogue should be terminated. The service key can be an integer value. The integer value in the service key can identify the service the CAP dialogue supports. 
         [0033]    The control action can be set by an IN service provider. The service provider can set the control action by accessing the GMSC  170 . For example, an IN service provider can indicate that all audio download CAP dialogues should be terminated but ring back tone CAP dialogues should not be terminated. The IN service provider can indicate the CAP dialogues that should be terminated and the CAP dialogues that should not be terminated by setting the control action. 
         [0034]    The control action can be automatically assigned a default value based on the service the CAP dialogue supports. The default value can be assigned by the GMSC  170 . For example, the GMSC  170  can always assign control action equal to do not terminate for all ring tone CAP dialogues. 
         [0035]    The GMSC  170  terminates the CAP dialogues that it determines should be terminated and does not terminate the CAP dialogues that it determines should not be terminated  302 . The GMSC  170  releases the call request towards the first MSC  130  by transmitting a REL message  304  to the first MSC  130 . The first MSC  130  releases the call request and transmits a RLC message  306  to the GMSC  170 . 
         [0036]    The GMSC  170  transmits a new SRI message  310  to the HLR  160 . The new SRI message  310  does not contain a MTRR indicator. The HLR  160  holds the SRI response message  312  until the location update is complete. The HLR  160  transmits an update location ACK message  314  to the second MSC  130 ′. Then the HLR  160  transmits an SRI ACK message  318  including T-CSI to the GMSC  170 . 
         [0037]    The GMSC  170  reestablishes the CAP dialogues that it terminated, and does not reestablish the CAP dialogues that it did not terminate  320 . The GMSC  170  queries the HLR  160  with a second request for the temporary number of the UE  105  by transmitting a SRI message  322 . The SRI message  272  indicates to the HLR  160  not to send a T-CSI in the SRI ACK with a suppress T-CSI indicator. The HLR  160  requests the temporary number from the second MSC  130 ′ by transmitting a PRN message  324 . The second MSC  130 ′ transmits a PRN ACK message  326  that includes the temporary number (MSRN) to the HLR  160 . The HLR  160  transmits an SRI ACK message  328  including the temporary number to the GMSC  170 . 
         [0038]    The GMSC  170  forwards an ISUP IAM message  330  to the second MSC  130 ′. The ISUP IAM message  280  includes the MSRN. The second MSC  130 ′ pages the UE  105  by transmitting a paging message  332  to the UE  105 . The UE  105  transmits a paging response message  334  to the second MSC  130 ′. Call delivery is completed by typical call delivery procedures, according to 3GPP standards. 
         [0039]    Whether or not a CAP dialogue should be terminated can depend on the service key of other CAP dialogues. For example, a first CAP dialogue can have a service key equal to 1, a second CAP dialogue can have a service key equal to 2. The GMSC can terminate the first CAP dialogue only if the second CAP dialogue has a service key equal to 3. The GMSC can terminate the second CAP dialogue if the first CAP dialogue has a service key equal to 1. In this example, the first CAP dialogue is not terminated and the second CAP dialogue is terminated. In another example, the first CAP dialogue and the second CAP dialogue are both terminated. In another example, the first CAP dialogue is terminated and the second CAP dialogue is not terminated. In another example, the first CAP dialogue and the second CAP dialogue are terminated. 
         [0040]    Whether or not the CAP dialogue should be terminated can depend on the type of CAMEL service the CAP dialogue provides. For example, it can be desirable to maintain video downloads, music downloads, prepaid service, automated call forwarding, and ring-back tone services. It can be desirable to terminate prepaid call services and dialing over a Virtual Private Network (VPN). 
         [0041]    The above described techniques can be implemented in a variety of ways. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). The system can include clients and servers. A client and a server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other. 
         [0042]    The above described techniques can be implemented by packet-based networks and/or circuit-based networks. Packet-based networks can include, for example, the Internet, a carrier internet protocol (IP) network (e.g., local area network (LAN), wide area network (WAN), campus area network (CAN), metropolitan area network (MAN), home area network (HAN)), a private IP network, an IP private branch exchange (IPBX), a wireless network (e.g., radio access network (RAN), 802.11 network, 802.16 network, general packet radio service (GPRS) network, HiperLAN), and/or other packet-based networks. Circuit-based networks can include, for example, the public switched telephone network (PSTN), a private branch exchange (PBX), a wireless network (e.g., RAN, bluetooth, code-division multiple access (CDMA) network, time division multiple access (TDMA) network, global system for mobile communications (GSM) network), and/or other circuit-based networks. 
         [0043]    Transmitting devices can include, for example, a computer, a computer with a browser device, a telephone, an IP phone, a mobile device (e.g., cellular phone, personal digital assistant (PDA) device, laptop computer, electronic mail device), and/or other communication devices. The browser device includes, for example, a computer (e.g., desktop computer, laptop computer) with a world wide web browser (e.g., Microsoft® Internet Explorer® available from Microsoft Corporation, Mozilla® Firefox available from Mozilla Corporation). The mobile computing device includes, for example, a personal digital assistant (PDA). 
         [0044]    Comprise, include, and/or plural forms of each are open ended and include the listed parts and can include additional parts that are not listed. And/or is open ended and includes one or more of the listed parts and combinations of the listed parts. 
         [0045]    One skilled in the art can appreciate the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting of the invention described herein. Scope of the invention is thus indicated by the appended claims, rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.