Abstract:
There is a need in the art for application servers to be able to exhibit the same behavior irrespective of the used access technology. In order to address this need the present invention provides methods and apparatuses for allowing one or more subscribers to be administratively registered.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/888,411, filed Feb. 6, 2007, the disclosure of which is incorporated herein by reference. 
    
    
     FIELD 
     The present invention relates to Internet Protocol Multimedia Subsystem networks. More particularly, the present invention relates to administrative registration of one or more users using IMS networks. 
     BACKGROUND 
     In Internet Protocol Multimedia Subsystem (IMS) networks, a terminal is required to register IMS public user identifiers to the IMS network in order to receive terminating calls for the IMS public user identifiers. The IMS also uses application servers (AS) to assist in providing services to IMS users. As such, the registration status of an IMS public user identifier is an indication of whether the network views that the user is reachable or not. As such, the Registration status impacts the application logic of application servers, and also which application servers can be invoked. 
     In addition to performing the initial Registration to the IMS network, a termination is required to periodically refresh the registration state in the network via performing the registration again. The terminal may also cancel the registration (e.g. before powering down). It is possible to administratively de-register a user from the network. 
     As such, a home subscriber server (HSS) recognizes that a user may be:
         Registered: A Public User Identity is Registered at the request of the user and has an S-CSCF assigned.   Un-Registered: A public User Identity is not registered but has a S-CSCF assigned to execute Unregistered state services as a consequence of a terminating call or there is a S-CSCF keep the profile stored   Not-Registered: Public Identity is not Registered and has no S-CSCF assigned.       

     System and service aspects of IMS (among other registration and de-registration procedures) are described in Third Generation Partnership Project (3GPP) Technical Specification (TS) 23.228 V7.5.0 (September 2006). A more detailed description of the service logic for some of these service aspects and procedures is given in 3GPP TS 29.228 V7.3.0 (September 2006). 
     Whether the Public user identity is Registered or Un-Registered/Not Registered may impact which application servers are invoked as different Filter Criteria is applied, and/or the behavior of the application logic within the application servers. This can imply that the expected behavior of an application server is different when the call originates from the circuit switch (CS) domain or the IMS domain, in that when originating/terminating a call to/from a packet switch (PS) access over IMS (normal access to IMS), the application servers will see that the user is Registered and apply registered services, however when originating/terminating a call via a CS access, the user may be unregistered. 
     One example is in the case of a terminating call for a voice call continuity (VCC) user. If the user is registered, the application logic is likely to try to deliver the call to the user, however if the user is not registered, the application logic is likely to forward the call to, e.g., a mail box. However, applications are appearing where a call may be made to or from a user, where the terminal for the user has not performed a registration. One example of this is VCC which is being progressed within 3GPP. TS 23.206 describes a VCC user entity (UE) that can originate and terminate a call without being registered to the IMS. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following section, the invention will be described with reference to exemplary embodiments illustrated in the figures, in which: 
         FIG. 1  illustrates a system for administrative registration according to one embodiment of the present invention; 
         FIG. 2  illustrates a method for providing administrative registration using the administration centre of  FIG. 1 , according to one embodiment of the present invention; 
         FIG. 3  illustrates a method for providing administrative registration using the home subscriber server of  FIG. 1 , according to one embodiment of the present invention; 
         FIG. 4  illustrates a method for providing administrative registration using the serving call session control function of  FIG. 1 , according to one embodiment of the present invention; 
         FIG. 5  illustrates a flow diagram of an Administrative Registration procedure for the system of  FIG. 1  according to one embodiment of the present invention; 
         FIG. 6  illustrates a system for providing administrative registration according to one embodiment of the present invention; 
         FIG. 7  illustrates a method for providing administrative registration using the administration centre of  FIG. 6  according to one embodiment of the present invention; 
         FIG. 8  illustrates a method for providing administrative registration using the serving call session control and home subscriber server of  FIG. 6  according to one embodiment of the present invention; and 
         FIG. 9  illustrates a flow diagram of an Administrative Registration procedure for the system of  FIG. 6  according to one embodiment of the present invention. 
     
    
    
     SUMMARY 
     There is a need in the art for application servers to be able to exhibit the same behavior irrespective of the used access technology. The present invention provides methods and apparatuses for providing administrative registration in IMS to address this need. 
     A method and apparatus for providing administrative registration in an internet protocol multimedia subsystem using an administration centre is provided. In one embodiment, user data of a user to be registered is obtained. A home subscriber server for the user is determined. An administrative request is sent to the home subscriber server. 
     A method and apparatus for providing administrative registration in an internet protocol multimedia subsystem using a home subscriber server is provided. In one embodiment, an administrative request is received. A determination is made as to whether a serving call session control function has been assigned for a user. The user is registered with the serving call session control function. The serving call session control function is provided with information from the administrative request. 
     A method and apparatus for providing administrative registration in an internet protocol multimedia subsystem using a serving call session control function is provided. In one embodiment, information associated with an administrative request is received. The received information is stored. Depending on the settings for the subscriber a third party registration may be performed when the information comprises initial filter information. 
     A method and apparatus for providing administrative registration in an internet protocol multimedia subsystem using an administration centre is provided. In one embodiment, user data of a user to be registered is obtained. A determination is made as to whether a serving call session control function has been allocated for the user. An administrative request is sent to the serving call session control function. 
     A method and apparatus for providing administrative registration in an internet protocol multimedia subsystem using a serving call session control function is provided. In one embodiment, an administrative request is received. Information associated with the administrative request is stored. A user is registered with a home subscriber server in response to the received administrative request. 
     DETAILED DESCRIPTION 
     The present invention provides methods and apparatuses for allowing one or more subscribers to be administratively registered. A subscriber, e.g., a user, may comprise a mobile device. The embodiments are not limited in this context. In one embodiment, the following can occur:
         The HSS is informed, via an administrative interface, that an IMS public user Identities (or set of public user Identities) should be registered.   A serving call session control function (S-CSCF) is selected for that IMS Public User identity (IMPU) (or all the IMS public User Identities that have the same subscription as the IMS Public User Identity against which the provision effort was performed).   That S-CSCF informed that the IMPU is administratively registered. In addition, the S-CSCF is provided with a session initiation protocol (SIP) path that ultimately identifies a SIP user agent (UA) to where the registration should be terminated. This includes going via the proxy call session control function (P-CSCF) functionality if required. In TS 24.229, this is referred to as the “Path header” that the S-CSCF received. The S-CSCF uses this to reach the P-CSCF using the “loose routing functionality”.       

     An alternative approach is that the S-CSCF is not informed upon administrative action, but upon another event—such as a call terminating call. In such a case, the S-CSCF would retrieve the information when it receives a SIP request for the administratively registered IMPU. 
       FIG. 1  illustrates a system  100  for providing administrative registration according to one embodiment. An administration centre  105  is connected to a home subscriber server (HSS)  110  via an Admin  1  interface. The Admin  1  interface is an interface used for O&amp;M and Service Provisioning. Although there have been initiatives to standardize the Admin  1  interface, this interface is primarily a proprietary interface when implemented in a product. In one embodiment, Administration Centre  105  looks up an HSS for a user and sends an administrative request, e.g., an Administrative Register Request to HSS  110 . HSS  110  registers the user with serving call session control function (S-CSCF)  115 . In one embodiment, HSS  110  registers the user with S-CSCF  115  over a Cx interface. HSS  110  also provides S-CSCF  115  with information determined from the administrative request. S-CSCF  115  communicates with multimedia resource function controller (MRFC)  125 , interrogating call session control function (I-CSCF)  130 , proxy call session control function (P-CSCF)  135 , and breakout gateway control function (BGCF)  140  via interfaces Mr, Mw, Mw, and Mi respectively. S-CSCF  115  communicates with session initiation protocol application server (SIP-AS)  120  via an IMS service control (ISC) interface. HSS  110  may also communicate with SIP-AS  120  via an Sh interface. SIP-AS  120 , MRFC  125 , I-CSCF  130 , P-CSCF  135 , and BGCF  140  are shown in  FIG. 1  for completeness, however, it should be apparent to one skilled in the art that S-CSCF  115  is not limited to connections with the aforementioned devices. 
       FIG. 2  illustrates a method  200  for providing administrative registration using administration centre  105 , according to one embodiment. In step  205 , user data of a user to be registered is obtained. In one embodiment, an operator enters/collects the necessary user data. The operator may comprise a human, machine, computer program, and so forth. In step  215 , a home subscriber server, e.g., HSS  110 , is determined for the user. In step  225 , an administrative request is sent to HSS  110 . The administrative request may comprise an S-CSCF name to register the user, the terminating route, and service information. 
       FIG. 3  illustrates a method  300  for providing administrative registration using HSS  110 , according to one embodiment. In step  305  an administrative request is received. In step  315  a determination is made as to whether a serving call session control function (S-CSCF) has been assigned for a user. In step  325 , the user is registered with an assigned S-CSCF, e.g., S-CSCF  115 . In step  335 , S-CSCF  115  is provided with information from the administrative request. 
       FIG. 4  illustrates a method  400  for providing administrative registration using S-CSCF  115 , according to one embodiment. In step  405 , information associated with an administrative request is received. In step  415 , the information associated with the administrative request is stored. In one embodiment, the information may comprise a terminating route, initial filter criteria, contact information. In step  425 , depending on the settings for the subscriber, a third party registration may be performed when the information comprises initial filter criteria. The third party registration is performed if the settings for that subscriber dictate that a third party registration is needed. In one embodiment, the settings for the subscriber are downloaded to the S-CSCF at the registration. 
       FIG. 5  illustrates a flow diagram of an Administrative Registration procedure according to one embodiment. The steps of  FIG. 5  may be implemented in system  100  of  FIG. 1 . The procedure of this embodiment comprises the following steps: 
     1. Operator (human/machine/computer program/etc) enters/collects the necessary user data of the user to be registered. 
     2. The administrative centre  105  looks up an HSS for the user and sends an administrative request to HSS  110 . The administrative request may comprise one or more identifiers of the user(s) to be registered. The request may also be applied for a plurality of users already provisioned in HSS  110 . The administrative request (2) may comprise the following information: 
     A) S-CSCF name to register the user; 
     B) the terminating route (In TS 24.229, this is referred to as the “Path header” that the S-CSCF received. The S-CSCF uses the path header to reach the P-CSCF using the “loose routing functionality”). The terminating route is the route that the S-CSCF will insert when it receives a request for a terminating call. Normally this information is the path towards a P-CSCF, however, for an administratively registered user, the terminating route may be a path towards a MGCF (to get to a mobile switching center (MSC)), private branch exchange (PBX), or any other circuit switched accesses. Any other circuit switched network means that the MGCF may be used to route to a PLMN (the MSC reference), a PSTN/ISDN network, to a PBX, etc. PSTN/ISDN/PLMN are all examples of CS networks; 
     C) service information (such as “Feature Tags”, IMS communication service identifiers, and/or other items to identify the terminal to be registered) are associated with the user, e.g., terminal, and stored in the S-CSCF. (“Feature Tags” fixes the problem of identifying a particular communication service when other data of said service, such as the media being used for it, is not sufficient to do so). Feature Tags express capabilities of registered contacts, i.e., capabilities of a registered terminal. Examples of FTs are audio, video, SIP methods—defined in RFC 2840/3841 and referred to as base feature tags. Other feature tags may be defined to express other capabilities than the ones that exist as base feature tags. Examples are +g.+g.oma.poc.talkburst for Push-to-talk, +g.oma.sip-im, +g.3gpp.app_ref=3gpp-service.ims.icsi.mmtel, etc. These services are implemented on top of IMS. Note that feature Tags are used for service identification in 3GPP, but it is not the complete solution. The complete solution for service identification in 3GPP is based on information in Feature Tags carried in Accept-Contact/Reject-Contact headers, and information carried in a P-Preferred-Service/P-Asserted-Service headers. The information provisioned in the present disclosure shall be used to construct these headers in signalling. 
     One example of an item to identify a terminal to be registered is a Globally Routable User Agent URI (Uniform Resource Identifier) (GRUU). The IMS architecture supports the possibility for multiple UEs (User Equipment/User Entity) to register with the same Public User Identity. Many IMS based enablers, such as Voice Call Continuity, Presence, Conferencing or Push To Talk, need to be able to identify the origin of SIP signalling and route that SIP signalling to a specific UE instance even when multiple UEs use the same Public User Identity. This issue is fixed by the assignation of GRUU to a specific UE, and its subsequent use for routing messages to a specific UE instance. 
     If the user already has an S-CSCF assigned due to, e.g., a previous registration or terminating call, the HSS will use the address to the assigned S-CSCF for the signalling in step 3. 
     If no S-CSCF has previously been assigned or a S-CSCF has been assigned that is not suitable for supporting registered traffic, the HSS will assign an S-CSCF based on the same criteria used for a normal IMS Registration (I-CSCF to HSS signalling where HSS returns “required-CSCF capability” back to the I-CSCF). 
     Alternatively, the administrative centre may send a SIP message to the S-CSCF (via the I-CSCF) to enable the I-CSCF to perform S-CSCF selection. 
     3. As a novel procedure between HSS and S-CSCF, the HSS sends a “Cx-Register” to the S-CSCF, for registering a user, providing the S-CSCF with the information received in step 2 above. In addition, the HSS may include “initial Filter Criteria” iFC. 
     4. S-CSCF  115  stores the terminating route (In TS 24.229, this is referred to as the “Path header” that the S-CSCF received. The S-CSCF uses this to reach P-CSCF  135  using “loose routing functionality”.), iFC (such as IMS communication service identifier), contact information, and the like. 
     5. The Cx-Register request is acknowledged. 
     6. HSS  110  stores the Registered S-CSCF name, and marks the subscriber as REGISTERED. 
     7. The administrative command is acknowledged. 
     8. If there were “initial Filter Criteria” for Registration, then the S-CSCF performs a “third party registration”. The “third party registration” procedure before an application server (AS) is detailed, e.g. in 3GPP TS 29.328 V7.4.0 (December 2006), for example in chapter B.1.1.1. According to this embodiment of the invention, the S-CSCF performs this procedure as a part of the novel processing related to the request received on step 3 above. 
     In one embodiment, a variation of the above flow occurs when the Administrative centre does not include a S-CSCF name. In this embodiment, the “Cx-Register” goes through I-CSCF  130  and I-CSCF  130  performs the S-CSCF selection, e.g., using similar selection criteria as disclosed in 3GPP specifications related to IMS procedures related to S-CSCF selection. 
       FIG. 6  illustrates a system  600  for providing administrative registration according to one embodiment. An administration centre  605  is connected to S-CSCF  615  via an Admin  2  interface. The Admin  2  interface is an interface used for operation and maintenance (O&amp;M) and Service Provisioning. Although there have been initiatives to standardize the Admin  2  interface, this interface is primarily a proprietary interface when implemented in a product. In one embodiment, Administration Centre  605  sends an administrative request, e.g., an Administrative Register Request to S-CSCF  615 . S-CSCF  615  registers a user with HSS  610 . In one embodiment, S-CSCF  615  registers the user with HSS  610  over a Cx interface. S-CSCF  615  communicates with multimedia resource function controller (MRFC)  625 , interrogating call session control function (I-CSCF)  630 , proxy call session control function (P-CSCF)  635 , and breakout gateway control function (BGCF)  640  via interfaces Mr, Mw, Mw, and Mi respectively. S-CSCF  615  communicates with session initiation protocol application server (SIP-AS)  620  via an IMS service control (ISC) interface. HSS  610  may also communicate with SIP-AS  620  via an Sh interface. SIP-AS  620 , MRFC  625 , I-CSCF  630 , P-CSCF  635 , and BGCF  640  are shown in  FIG. 6  for completeness, however, it should be apparent to one skilled in the art that S-CSCF  615  is not limited to connections with the aforementioned devices. 
       FIG. 7  illustrates a method for providing administrative registration using administration centre  605  according to one embodiment. In step  705 , user data of a user to be registered is obtained. In one embodiment, an operator enters/collects the necessary user data. The operator may comprise a human machine, computer program, and so forth. In step  715 , a determination is made as to whether an S-CSCF has been allocated for the user. In step  725  an administrative request is sent to the allocated S-CSCF, e.g., S-CSCF  615 . 
       FIG. 8  illustrates a method for providing administrative registration using S-CSCF  615  and HSS  610  according to one embodiment. In step  805 , an administrative request is received at S-CSCF  615 , e.g. from administration centre  605 . In step  815 , information associated with the administrative request is stored at S-CSCF  615 . In step  825  a user is registered with HSS  610  in response to the received administrative request. 
       FIG. 9  illustrates a flow diagram of an Administrative Registration procedure according to one embodiment. 
     1. Operator (human/machine/computer program/etc) enters/collects the necessary user data of the user to be registered. 
     2. The administrative centre sends an administrative request to the S-CSCF. The administrative request can comprise an identifier of the user(s) to be registered. The request can be also run for a plurality of users already provisioned in the HSS. The administrative request (2) may contain the following information: 
     A) the terminating route (In TS 24.229, this is referred to as the “Path header” that the S-CSCF received. The S-CSCF uses this to reach the P-CSCF using the “loose routing functionality”). The terminating route is the route that the S-CSCF will insert when it receives a request for a terminating call. Normally this information is the path towards a P-CSCF, however, for an administratively registered user, the terminating route may be a path towards a MGCF (to get to a mobile switching center (MSC)), private branch exchange (PBX), or any other circuit switched accesses. Any other circuit switched network means that the MGCF may be used to route to a PLMN (the MSC reference), a PSTN/ISDN network, to a PBX, etc. PSTN/ISDN/PLMN are all examples of CS networks; 
     B) service information (such as “Feature Tags”, IMS communication service identifiers, and/or other items to identify the terminal to be registered) are associated with the user, e.g., terminal, and stored in the S-CSCF. (“Feature Tags” fixes the problem of identifying a particular communication service when other data of said service, such as the media being used for it, is not sufficient to do so). Feature Tags express capabilities of registered contacts, i.e., capabilities of a registered terminal. Examples of FTs are audio, video, SIP methods—defined in RFC 2840/3841 and referred to as base feature tags. Other feature tags may be defined to express other capabilities than the ones that exist as base feature tags. Examples are +g.+g.oma.poc.talkburst for Push-to-talk, +g.oma.sip-im, +g.3gpp.app_ref=3gpp-service.ims.icsi.mmtel, etc. These services are implemented on top of IMS. Note that feature Tags are used for service identification in 3GPP, but it is not the complete solution. The complete solution for service identification in 3GPP is based on information in Feature Tags carried in Accept-Contact/Reject-Contact headers, and information carried in a P-Preferred-Service/P-Asserted-Service headers. The information provisioned in the present disclosure shall be used to construct these headers in signalling. 
     One example of an item to identify a terminal to be registered is a Globally Routable User Agent URI (Uniform Resource Identifier) (GRUU). The IMS architecture supports the possibility for multiple UEs (User Equipment/User Entity) to register with the same Public User Identity. Many IMS based enablers, such as Voice Call Continuity, Presence, Conferencing or Push To Talk, need to be able to identify the origin of SIP signalling and route that SIP signalling to a specific UE instance even when multiple UEs use the same Public User Identity. This issue is fixed by the assignation of GRUU to a specific UE, and its subsequent use for routing messages to a specific UE instance. 
     The Administrative Centre may find an already allocated S-CSCF by using the Sh interface towards HSS. The Administrative Centre uses the Diameter protocol to signal the HSS over the Sh interface. 
     If a S-CSCF has not been allocated, the administrative centre may select a S-CSCF based on the same criteria that the I-CSCF, e.g., I-CSCF  630 , uses. 
     Alternatively, in one embodiment, administrative centre  605  sends a SIP message to S-CSCF  615  (via I-CSCF  630 ) to enable the I-CSCF to perform S-CSCF selection. 
     3. S-CSCF  615  stores the terminating route (In TS 24.229, this is referred to as the “Path header” that the S-CSCF received. The S-CSCF uses the path header to reach the P-CSCF using the “loose routing functionality”). 
     4. S-CSCF  615  performs the registration procedures toward HSS  610  (Cx-Put/Cx-Pull). This registration procedure may be accomplished by using the procedures that exist presently on the Cx interface, which, according to this embodiment of the invention, are triggered by the reception of the request of flow  2 . 
     5. The registration procedure towards HSS  610  is acknowledged. 
     6. The administrative registration request is acknowledged. 
     7. If there were “initial Filter Criteria” for Registration, then the S-CSCF performs the required 3rd party registration, as cited earlier with reference to the embodiment of  FIG. 1  and  FIG. 5 . 
     The above approach requires persistent storage of information in the S-CSCF. This is a new requirement on the S-CSCF. 
     Terminating calls to the S-CSCF for the administratively registered users work in the same manner as for users “normally” registered from terminals. 
     Currently, telecommunications nodes, such as: HSSs, CSCFs, or even provisioning apparatuses (e.g. as it could be the illustrated “Administration Centre”), are mostly implemented in computer-based machines. Accordingly, computer programs comprising computer-readable program codes are loaded in computer-based machines of telecommunications systems, causing them to behave according to a predefined manner, as determined by the respective program codes, which are in accordance to the specific functionality specified for the telecommunications nodes these machine implements. Thus, those skilled in creating and/or modifying computer programs, would, without departing of the teachings of the present invention, readily apply them to create and/or modify computer programs suitable to be loaded in a computer-based nodes and apparatuses, so as to make them to behave according to any of the described embodiments. 
     The invention has been described with respect to some exemplary embodiments in an illustrative and non-restrictive manner. Variations can be readily apparent to those of ordinary skill in the art. While one application of the present disclosure is to target applications accessing over a CS access, it should be noted that the present disclosure is also applicable to IP-PBX, e.g., any enterprise connection, where the enterprise equipment does not perform the registration. 
     The administrative registrations of users according to the invention, allows a given user to receive services (e.g. make/receive multimedia calls) provided by a first telecommunications network, such as IMS, while connected to a second telecommunications network, such as a PSTN, or other network providing only basic CS services. The operator of a device, e.g. a mobile device, is thus not required to use a specific terminal suited for the first network so as to perform a standard registration in said first network. Further, the solutions of the invention do not require the introduction of any new node in the first telecommunications network.