Patent Publication Number: US-2007104207-A1

Title: Selective handling of user equipment

Description:
FIELD OF THE INVENTION  
      The invention relates to a method and a device for selective handling of user equipment in a telecommunications network.  
     DESCRIPTION OF PRIOR ART  
      Telecommunications networks such as GSM (Global System for Mobile communications) networks, GPRS (General Packet Radio System) networks or UMTS (Universal Mobile Telecommunication System) networks comprise a database for registering user equipment. The registration of user equipment entails user equipment identification and a permission status of the user equipment. The user equipment identification may be the IMEI (International Mobile Equipment Identity) as specified by 3GPP (3 rd  Generation Partnership Project) in TS 22.016, V5.0.0, published 2002 Jun. 13.  
      An example of a database registering user equipment is the EIR (Equipment Identity Register). The EIR comprises three registers, known as ‘white list’, ‘black list’ and ‘grey list’. User equipment assigned to the white list is deemed permitted for use. User equipment assigned to the black list is deemed not permitted for use. User equipment assigned to the grey list is deemed permitted for use, but should be monitored by the network.  
      A control node may query the EIR to obtain the permission status of a user equipment that is currently registered with the control node. The control node may be a MSC (Mobile Services Switching Centre) in the case of a GSM or UMTS network, or a SGSN (Serving GPRS Support Node) in the case of a GPRS or UMTS network. A network architecture that enables querying the EIR by a control node is specified in 3GPP TS 23.002, V.6.5.0, published 2004 Jun. 23. According to this architecture, messages are exchanged via a so-called F-interface between the MSC and the EIR or via a so-called Gf-interface between the SGSN and the EIR respectively. The Mobile Application Part (MAP) is used as signaling protocol on these interfaces.  
      Based on the result of the query the control node may decide whether the network accepts the user equipment. In the case of user equipment that is deemed not permitted for use, the control node may not accept registration by the user equipment or it may terminate a call set-up request by the user equipment.  
      The mechanism for checking the permission status of user equipment according to the state of the art has a number of shortcomings. Once user equipment has registered with a control node and does not perform a location update after registration, the control node will not query the EIR when the user equipment is switched off and on. In the period between detaching from the control node and a subsequent re-attaching to that control node, the subscriber may have changed the SIM (Subscriber Identity Module) from one user equipment to another; this may not be noticed by the control node.  
      Another shortcoming relates to roaming. If the control node would check the user equipment of an inbound roaming subscriber, i.e. a subscriber visiting the network comprising the control node, the EIR of the visited network may not comprise status information about the user equipment, because the status information may be stored only in the EIR of the home network. Because a control node is normally configured with a single EIR address only, it may not obtain status information for such subscriber.  
     SUMMARY OF THE INVENTION  
      It is an object of the invention to provide an improved way of handling an attribute related to user equipment.  
      This object is achieved by the method of claim  1  and the Service Control Point of claim  8 .  
      The invention provides a method for selective handling of user equipment implemented in a Service Control Point. The Service Control Point performs the steps of receiving a service request, determining a user equipment identifier, requesting a user equipment attribute, receiving the user equipment attribute and initiating an appropriate action based on the user equipment attribute.  
      In an embodiment of the invention the user equipment attribute comprises an indication that the user equipment is not permitted for use and the step of initiating an appropriate action based on the user equipment attribute comprises a step of initiating the termination of servicing the user equipment.  
      In a further embodiment of the invention the user equipment attribute comprises an indication that the user equipment is permitted for use and the step of initiating an appropriate action based on the user equipment attribute comprises a step of continuing servicing the user equipment.  
      In a further embodiment of the invention the user equipment attribute comprises an indication of a particular deficiency of the user equipment.  
      In a further embodiment of the invention the step of initiating an appropriate action based on the user equipment attribute comprises a step of initiating an appropriate deficiency handling based on said particular deficiency.  
      In a further embodiment of the invention the step of determining a user equipment identifier comprises a step of receiving the user equipment identifier in the service request.  
      In a further embodiment of the invention the step of determining a user equipment identifier comprises the steps of requesting a user equipment identifier from a user equipment and receiving the user equipment identifier from the user equipment.  
      The invention further provides a Service Control Point for a telecommunications network. The Service Control Point comprises a service handling unit for handling a service request, a processing unit for controlling further units, a user equipment identifier determining unit for determining a user equipment identifier and an interface unit for requesting a user equipment attribute and receiving the user equipment attribute.  
      In an embodiment of the invention the service control point is adapted to handle a user equipment attribute that comprises an indication that the user equipment is not permitted for use and the Service Control Point further comprises a service termination unit for initiating the termination of servicing the user equipment.  
      In a further embodiment of the invention the service control point is adapted to handle a user equipment attribute that comprises an indication of a particular deficiency of the user equipment.  
      In a further embodiment of the invention the Service Control Point further comprises a deficiency handling unit for initiating an appropriate deficiency handling based on the particular deficiency.  
      In a further embodiment of the invention the service handling unit is arranged to process a user equipment identifier in the service request.  
      In a further embodiment of the invention the Service Control Point further comprises an interface unit for requesting a user equipment identifier and receiving the user equipment identifier. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  depicts a signal flow between entities involved illustrating a possible sequence of steps for selective handling of user equipment according to a first embodiment of the invention.  
       FIG. 2  depicts a signal flow between entities involved illustrating a possible sequence of steps for selective handling of user equipment according to a second embodiment of the invention.  
       FIG. 3  depicts a signal flow between entities involved illustrating a possible sequence of steps for selective handling of user equipment according to a third embodiment of the invention.  
       FIG. 4  depicts a signal flow between entities involved illustrating a possible sequence of steps for selective handling of user equipment according to a fourth embodiment of the invention.  
       FIG. 5  depicts a Service Control Point according to the invention. 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS  
       FIG. 1  shows a method for selective handling of user equipment in a telecommunications network according to a first embodiment of the invention. The telecommunications network may be for example a network operating according to GSM, GPRS or UMTS standards. The telecommunications network comprises a control node CN 1  that is servicing a subscriber using a user equipment UE 101 . The control node may be embodied in a MSC (Mobile Services Switching Centre) in the case of a GSM or UMTS network, or in a SGSN (Serving GPRS Support Node) in the case of a GPRS or UMTS network.  
      The telecommunications network further comprises a service control point SCP 1 . The service control point SCP 1  comprises service logic and data that allows it to send instructions to the control node CN 1 . According to the invention, the service control point SCP 1  exchanges information with an equipment database ED 1  storing user equipment attributes. The equipment database ED 1  may also be part of the telecommunications network. The equipment database ED 1  may be an Equipment Identity Register (EIR) or another suitable database arranged to store information regarding user equipment. In the case of an EIR the user equipment attributes may comprise indications of a permission status of a particular user equipment. The permission status may indicate that the particular user equipment is ‘black-listed’, i.e. deemed not permitted for use, or ‘white-listed’, i.e. deemed permitted for use, or ‘grey-listed’, i.e. neither ‘black-listed’ nor ‘white-listed’, but use of such user equipment should be tracked by the telecommunications network. In another embodiment of the invention, depicted for example in  FIG. 4 , the user equipment attributes comprise an indication of a particular deficiency known of the user equipment. Such deficiency may be an implementation of functionality in the user equipment that does not comply with defined telecommunications standards. An example is the registration of implementation faults of early UMTS equipment, as specified in TS25.994, V0.0.0, published 2003 Jan. 06.  
      The telecommunications network further comprises a further user equipment UE 102 . For reasons of simplicity the control node servicing user equipment UE 102  is not depicted.  
      In a first step S 101  a user equipment UE 101  sends a call set-up request to a control node CN 1 . A user equipment identifier of the user equipment UE 101  may be known to the control node CN 1 . If this is not the case, then the control node CN 1  may request the user equipment UE 101  to provide the user equipment identifier, not depicted. Preferably the user equipment identifier is the International Mobile Equipment Identifier (IMEI). The call set-up request also comprises a destination number of a called subscriber. Upon receipt of the call set-up request the control node CN 1  sends a service request comprising the user equipment identifier and the destination number of the called subscriber to the service control point SCP 1  in a step S 102 . The service control point SCP 1  requests an equipment database ED 1  to provide a user equipment attribute based on the user equipment identifier in a step S 103 . In a step S 104  the equipment database ED 1  sends the user equipment attribute to the service control point SCP 1 . The user equipment attribute may comprise indications of a permission status of the user equipment. The permission status may indicate that the user equipment is not permitted for use, or is permitted for use. The user equipment attribute may also or instead comprise an indication of a particular deficiency known of the user equipment. Such deficiency may be an implementation of functionality in the user equipment that does not comply with defined telecommunications standards. In the following the check of a permission is described as an example, however, the same steps may be performed when checking for deficiencies.  
      In a step S 105  the service control point SCP 1  analyses the destination number to determine whether it belongs to a mobile subscriber. According to this example, the called subscriber is a mobile subscriber using a user equipment UE 102 . Alternatively, if the called subscriber is not a mobile subscriber, then the following steps S 106  to S 109  may be omitted. In a step S 106  the service control point SCP 1  contacts the user equipment UE 102  via a Home Location Register and a control node servicing the user equipment UE 102 , not depicted, to retrieve a user equipment identifier of the called subscriber. In a step S 107  the user equipment UE 102  sends the user equipment identifier towards the service control point SCP 1 . In a step S 108  the service control point SCP 1  requests the equipment database ED 1  to provide a user equipment attribute based on the user equipment identifier of UE 102 . In a step S 109  the equipment database ED 1  sends the user equipment attribute to the service control point SCP 1 .  
      In a step S 110  the service control point SCP 1  analyses the user equipment attributes of user equipment UE 101  and of user equipment UE 102  respectively. If either one or both of the equipment attributes of user equipment UE 101  or user equipment UE 102  indicates that the respective user equipment is not permitted for use, then the service control point SCP 1  sends an instruction to the control node CN 1  to terminate the call-set up in a step S 111 . If the user equipment attributes indicate that the user equipment UE 101  and the user equipment UE 102  are permitted for use, then the service control point SCP 1  sends a notification to the control node CN 1  to continue call-set up in a step S 111 .  
      If the called subscriber is not a mobile subscriber according to the check of step S 105 , then the service control point SCP 1  analyses in step S 110  the user equipment attribute of the user equipment UE 101  as retrieved in steps S 103  and S 104 . If the user equipment attribute indicates that the user equipment UE 101  is not permitted for use, then the service control point SCP 1  sends an instruction to the control node CN 1  to terminate the call-set up in a step S 111 . If the user equipment attribute indicates that the user equipment UE 101  is permitted for use, then the service control point SCP 1  sends a notification to the control node CN 1  to continue call-set up in a step S 111 .  
      As an alternative to the above-described embodiment the user equipment attributes of user equipment UE 101  and UE 102  may also relate to particular deficiencies known about the user equipment.  
       FIG. 2  depicts a further embodiment according to the invention. User equipment UE 2 , control node CN 2 , service control point SCP 2  and equipment database ED 2  are similar to the respective entities as defined in the description of  FIG. 1 .  
      In a step S 201  a user equipment UE 2  sends a short message to a control node CN 2 . Upon receipt of the short message the control node CN 2  sends a service request to a service control point SCP 2  in a step S 202 . In this embodiment the control node CN 2  does not include the user equipment identifier of user equipment UE 2  in the service request. In a step S 203  the service control point SCP 2  contacts the user equipment UE 2  via a Home Location Register and the control node CN 2 , to retrieve the user equipment identifier of the user equipment UE 2 , not depicted. In a step S 204  the user equipment UE 2  sends the user equipment identifier towards the service control point SCP 2 . In a step S 205  the service control point SCP 2  requests an equipment database ED 2  to provide a user equipment attribute based on the user equipment identifier of UE 2 . In a step S 206  the equipment database ED 2  sends the user equipment attribute to the service control point SCP 2 .  
      The service control point SCP 2  analyses the user equipment attribute of the user equipment UE 2  in step S 207 . If the user equipment attribute indicates that the user equipment UE 2  is not permitted for use, then the service control point SCP 2  sends an instruction to the control node CN 2  to terminate the short message transmission in a step S 208 . If the user equipment attribute indicates that the user equipment UE 2  is permitted for use, then the service control point SCP 2  sends a notification to the control node CN 2  to continue the short message transmission in a step  208 .  
       FIG. 3  depicts a further embodiment according to the invention. In this embodiment control node CN 3  is a SGSN and equipment database ED 3  is an EIR.  
      In a step S 301  a user equipment UE 3  sends a request for Packet Data Protocol (PDP) context establishment to a control node CN 3 . Upon receipt of the request the control node CN 3  sends a service request comprising the user equipment identifier of UE 3  to a service control point SCP 3  in a step S 302 . In a step S 303  the service control point SCP 3  requests an equipment database ED 3  to provide a user equipment attribute based on the user equipment identifier of UE 3 . In a step S 304  the equipment database ED 3  sends the user equipment attribute to the service control point SCP 3 .  
      The service control point SCP 3  analyses the user equipment attribute of the user equipment UE 3  in step S 305 . If the user equipment attribute indicates that the user equipment UE 3  is not permitted for use, then the service control point SCP 3  sends an instruction to the control node CN 3  to terminate the PDP context establishment in a step S 306 . If the user equipment attribute indicates that the user equipment UE 3  is permitted for use, then the service control point SCP 3  sends a notification to the control node CN 3  to continue the PDP context establishment in a step  306 .  
       FIG. 4  depicts a further embodiment according to the invention. In this embodiment control node CN 4  is a MSC and equipment database ED 4  registers user equipment attributes comprising indications of deficiencies of user equipment.  
      In a step S 401  a user equipment UE 4  sends a request for a video call to a control node CN 4 . Upon receipt of the request the control node CN 4  sends a service request comprising the user equipment identifier of UE 4  to a service control point SCP 4  in a step S 402 . In a step S 403  the service control point SCP 4  requests an equipment database ED 4  to provide a user equipment attribute based on the user equipment identifier of UE 4 . In a step S 404  the equipment database ED 4  sends the user equipment attribute to the service control point SCP 4 .  
      The service control point SCP 4  analyses the user equipment attribute of the user equipment UE 4  in step S 405 . If the user equipment attribute indicates that the user equipment UE 4  has a deficiency that does support to set up a video call, or not in the requested way, then the service control point SCP 4  sends an instruction to the control node CN 4  to fall back to a speech call in a step S 406 . If the user equipment attribute indicates that the user equipment UE 4  has no such deficiency, then the service control point SCP 4  sends a notification to the control node CN 4  to continue the request for a video call in a step  406 .  
      In  FIG. 5 a  service control point SCP 5  according to an embodiment of the invention is depicted. The service control point SCP  5  comprises a service handling unit SHU 5  for handling a service request, a processing unit PU 5  for controlling further units, a user equipment identifier determining unit IDU 5  for determining a user equipment identifier, an interface unit IFI 5  for requesting a user equipment identifier and receiving the user equipment identifier, an interface unit IFA 5  for requesting a user equipment attribute and receiving the user equipment attribute, a service termination unit STU 5  for initiating the termination of servicing a user equipment and a deficiency handling unit DHU 5  for initiating an appropriate deficiency handling based on a particular deficiency. Via the interface unit IFI 5  the service control point SCP 5  contacts a user equipment, e.g. via a HLR Home Location Register and a control node servicing the user equipment. Via the interface unit IFA 5  the service control point SCP 5  interfaces with one or more external databases comprising user equipment attributes. Each of the units SHU 5 , PU 5 , IDU 5 , IFI 5 , IFA 5 , STU 5  and DHU 5  can be implemented in hardware or software or a combination of both.  
      According to an embodiment of the invention, the service handling unit SHU 5  receives a service request. The service request comprises a user equipment identifier of a user equipment of a calling subscriber and preferably a destination number of a called subscriber. Via the interface unit IFA 5  the processing unit requests an external database to provide a user equipment attribute based on the user equipment identifier of the user equipment of the calling subscriber. The interface unit IFA 5  receives the user equipment attribute from the external database. According to an embodiment of the invention the processing unit analyses the destination number of the called subscriber. If the called subscriber is a mobile subscriber, then the user equipment identifier determining unit IDU 5  contacts the user equipment of the called subscriber via the interface unit IFI 5  to request the user equipment identifier of the user equipment of the called subscriber. The interface unit IFI 5  receives the user equipment identifier of the user equipment of the called subscriber. The processing unit requests an external database via interface unit IFA 5  to provide a user equipment attribute based on the user equipment identifier of the user equipment of the called subscriber. The external database might be the same database as contacted in the case of the calling subscriber or a different database. The choice of external database depends on the user equipment identifier of the user equipment for which the user equipment attribute is retrieved. The interface unit IFA 5  receives the user equipment attribute of the user equipment of the called subscriber from the external database. The processing unit analyses the user equipment attributes of the user equipments of the calling and called subscriber respectively. If in a particular embodiment of the invention, either one or both of the user equipment attributes of the calling or called subscriber indicates that the respective user equipment is not permitted for use, then the service termination unit STU 5  initiates the termination of servicing the user equipment, e.g. by sending an instruction to a control node to terminate a request for call set-up. If the user equipment attributes indicate that both the user equipment of the calling and the user equipment of the called subscriber are permitted for use, then the processing unit sends a notification to a control node to continue e.g. a request for call-set up.  
      If in a further particular embodiment of the invention, the user equipment attribute of the user equipment of the calling or called subscriber comprises an indication of a particular deficiency known of the user equipment, then the deficiency handling unit DHU 5  analyses the indication of the particular deficiency and initiates an appropriate deficiency handling based on said particular deficiency, e.g. by sending an instruction to a control node to disallow a request for a video call and allow a speech call only for the user equipment.