(19)
(11)EP 2 522 102 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
23.11.2016 Bulletin 2016/47

(21)Application number: 10841605.8

(22)Date of filing:  22.12.2010
(51)International Patent Classification (IPC): 
H04L 29/08(2006.01)
H04L 12/24(2006.01)
H04W 8/18(2009.01)
H04L 12/14(2006.01)
H04M 15/00(2006.01)
H04W 8/04(2009.01)
(86)International application number:
PCT/US2010/061934
(87)International publication number:
WO 2011/082090 (07.07.2011 Gazette  2011/27)

(54)

METHOD, SYSTEM, AND COMPUTER READABLE MEDIUM FOR POLICY CHARGING AND RULES FUNCTION (PCRF) NODE SELECTION

VERFAHREN, SYSTEM UND COMPUTERLESBARES MEDIUM ZUR KNOTENAUSWAHL MIT VORSCHRIFTEN- UND LADEREGELFUNKTION (PCRF)

PROCÉDÉ, SYSTÈME ET SUPPORT LISIBLE PAR ORDINATEUR POUR LA SÉLECTION DE NOEUDS DE LA FONCTION DE RÈGLES DE POLITIQUE ET DE FACTURATION (PCRF)


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 04.01.2010 US 292062 P
21.12.2010 US 974869
21.10.2010 US 405629 P

(43)Date of publication of application:
14.11.2012 Bulletin 2012/46

(73)Proprietor: Tekelec, Inc.
Morrisville, NC 27560 (US)

(72)Inventors:
  • BANIEL, Uri
    Marlborough MA 01752 (US)
  • JACKSON, Ken
    Marlborough MA 01752 (US)
  • ABOU-ASSALI, Tarek
    Boston MA 02111 (US)
  • MERCURIO, Michael
    Jamaica Plain MA 02130 (US)
  • SPRAGUE, David Michael
    Raleigh NC 27615 (US)

(74)Representative: Gill Jennings & Every LLP 
The Broadgate Tower 20 Primrose Street
London EC2A 2ES
London EC2A 2ES (GB)


(56)References cited: : 
EP-A1- 1 357 720
US-A1- 2009 265 467
WO-A1-2009/086759
US-B1- 6 298 383
  
  • "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Policy and charging control architecture (Release 9)", 3GPP STANDARD; 3GPP TS 23.203, 3RD GENERATION PARTNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE ; 650, ROUTE DES LUCIOLES ; F-06921 SOPHIA-ANTIPOLIS CEDEX ; FRANCE, no. V9.3.0, 10 December 2009 (2009-12-10), pages 1-123, XP050400588, [retrieved on 2009-12-10]
  • CISCO SYSTEMS ET AL: "Cisco Content Services Gateway - 2nd Generation Release 3.5 Installation and Configuration Guide, Chapter 10 (Configuring Gx Support) , Chapter 11 (Configuring Mobile PCC Support)", CISCO CONTENT SERVICES GATEWAY - 2ND GENERATION RELEASE 3.5 INSTALLATION AND CONFIGURATION GUIDE , no. Revision OL-19290-01 pages 10-1, XP002584240, Retrieved from the Internet: URL:http://www.cisco.com/en/US/docs/wirele ss/csg2/3.5/installation/guide/csg3-51.pdf [retrieved on 2009-06-05]
  
Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


Description

TECHNICAL FIELD



[0001] The subject matter described herein relates to identifying PCRF nodes in communications networks. More particularly, the subject matter described herein relates to PCRF node selection in a network with plural PCRFs and/or plural diameter relay agents (DRAs) or other nodes that perform PCRF node selection.

BACKGROUND



[0002] In communications networks, such as long term evolution (LTE) networks, the PCRF is the node that executes user policies that control aspects of a user's network services, such as authentication, authorization, bandwidth, other quality of service features, etc. A PCRF may obtain the policies for subscribers from another node referred to as a subscription profile repository (SPR), which may be co-located with a home subscriber server (HSS). The PCRF may communicate with a policy and charging enforcement function (PCEF), which enforces policies for subscriber terminals. When a user first communicates with a network, the user is assigned to a PCRF. Once a PCRF has been assigned, subsequent session related traffic for the user must be sent to the same PCRF because the PCRF stores policy state for the user. For example, the PCRF may store the volume of data accessed by the user while the user is attached to the network. The user's policy maintained by the PCRF may specify that the user's network access bandwidth is to be adjusted once the volume of accessed data reaches a threshold level. In order to manage such a policy, all traffic intended for the user during a particular network attachment must traverse the same PCRF.

[0003] More generally, when a node seeks to establish a session with the user, the node may contact the PCRF to request a particular level or quality of service for the session. The PCRF may execute the user's policy and respond to the request, indicating the quality of service that will be provided for the session. The PCRF may instruct the PCEF to enforce the policy as communicated to the requesting node.

[0004] Another function performed by the PCRF is charging. The PCRF may implement charging on a per packet flow basis. Packets matching filters of a particular policy rule are referred to as a service data flow (SDF). By identifying all packets associated with the same flow, the PCRF may charge for the flow in accordance with policy rules defined for the subscriber.

[0005] A DRA is responsible for routing or relaying Diameter signaling messages between Diameter nodes. In networks with very few Diameter nodes (such as PCRFs), there may be little need for a DRA. However, as the number of subscribers served by a network increases, it is necessary to scale the policy control functionality of the network and thus to add PCRFs and other Diameter nodes to the network. With plural PCRFs, it may be necessary to add plural DRAs to the network. While DRAs route Diameter signaling messages based on Diameter parameters, the base Diameter protocol specified in IETF RFC 3588 does not specify a methodology for selecting a PCRF in a network with plural PCRFs. As set forth above, there is a need to assign a PCRF to a user when the user first connects or attaches to the network and to ensure that subsequent session related traffic for the user is routed to the same PCRF. When there are plural DRAs and/or PCRFs in a network, optimally assigning subscribers to a PCRF and ensuring the proper routing of signaling after assignment has been made become important.

[0006] Accordingly, there exists a need for methods, systems, and computer readable media for PCRF node selection.

[0007] WO 2009/086759 A1 (ZTE CORP [CN]; ZHOU XIAOYUN [CN]; ZONG ZAIFENG [CN]; RUI TONG [CN]; ZH) 16 July 2009 (2009-07-16); & US 2010/291923 A1 (ZHOU XIAOYUN [CN] ET AL) 18 November 2010 (2010-11-18), discloses background information.

[0008] "3rd Geneation Partnership Project; Technical Specification Group Services and System Aspects; Policy and charging control architecture (Release 9)", 3GPP STANDARD; 3GPP TS 23.203, 3RD GENERATION PARNERSHIP PROJECT (3GPP), MOBILE COMPETENCE CENTRE; 650, ROUTE DES LUCIOLES; F-06921 SOPHIA-ANTIPOLIS CEDEX; FRANCE, no. V9.3.0, 10 December 2009 (2009-12-10), pages 1-123, XP050400588, [retrieved on 2009-12-10], discloses background information.

SUMMARY



[0009] According to a first aspect of the invention, there is provided a system as set out in claim 1.

[0010] According to a second aspect of the invention, there is provided a method as set out in claim 5.

[0011] According to a third aspect of the invention, there is provided a computer readable medium as set out in claim 9. The subject matter described herein for PCRF node selection may be implemented using a non-transitory computer readable medium having stored thereon executable instructions that when executed by the processor of a computer control the computer to perform steps. Exemplary computer readable media suitable for implementing the subject matter described herein include disk memory devices, chip memory devices, programmable logic devices, and application specific integrated circuits. In addition, a computer readable medium that implements the subject matter described herein may be located on a single device or computing platform or may be distributed across plural devices or computing platforms.

BRIEF DESCRIPTION OF THE DRAWINGS



[0012] Preferred embodiments of the subject matter described herein will now be described with reference to the accompanying drawings of which:

Figure 1 is a network diagram illustrating an exemplary system for PCRF node selection according to an embodiment of the subject matter described herein;

Figure 2 is a message flow diagram illustrating exemplary messages that are exchanged for static PCRF node selection where a PCRF selection node locally performs PCRF node selection according to an embodiment of the subject matter described herein;

Figure 3 is a message flow diagram illustrating exemplary messages exchanged for static PCRF node selection where selection of the PCRF is delegated from a first PCRF selection node to a second PCRF selection node according to an embodiment of the subject matter described herein;

Figure 4 is a message flow diagram illustrating static PCRF node selection where a PCRF selection node uses a previously selected PCRF node according to an embodiment of the subject matter described herein;

Figure 5 is a message flow diagram illustrating static PCRF selection for an application function (AF) session where a PCRF selection node delegates PCRF selection according to an embodiment of the subject matter described herein;

Figure 6 is a message flow diagram illustrating dynamic PCRF node selection where a PCRF is selected locally by a PCRF selection node according to an embodiment of the subject matter described herein;

Figures 7A and 7B are a message flow diagram illustrating dynamic PCRF selection where PCRF selection is delegated according to an embodiment of the subject matter described herein;

Figure 8 is a message flow diagram illustrating exemplary messages exchanged for dynamic PCRF selection for an AF session where a PCRF selection node selects a previously selected PCRF according to an embodiment of the subject matter described herein;

Figure 9 is a message flow diagram illustrating dynamic PCRF selection for an AF session where a PCRF selection node delegates PCRF selection according to an embodiment of the subject matter described herein;

Figure 10 is a flow chart illustrating exemplary steps for PCRF node selection according to an embodiment of the subject matter described herein;

Figure 11 is a block diagram of an exemplary PCRF selection node according to an embodiment of the subject matter described herein; and

Figure 12 is a network diagram where PCRF selection state is maintained by a subscription binding repository (SBR) according to an embodiment of the subject matter described herein.


DETAILED DESCRIPTION



[0013] Methods, systems, and computer readable media for PCRF node selection are provided. Figure 1 is a block diagram illustrating an exemplary network including a system for PCRF node selection according to an embodiment of the subject matter described herein. Referring to Figure 1, the network includes PCRF selection nodes 100, 102, and 103 that perform PCRF selection among PCRF nodes 1041-1043, 1061-1064, and 1081-1082, respectively. Each PCRF is capable of executing policies for subscribers in a communications network, including wireless and/or wireline networks. An exemplary network for implementing the subject matter described herein is an LTE network. Each PCRF selection node 100, 102, and 103 include the ability to select and route signaling to the proper PCRF for a subscriber. In addition, each PCRF selection node 100, 102, and 103 may include DRA functionality.

[0014] The network illustrated in Figure 1 further includes packet gateway/home service gateways (PGW/HSGWs) 110 and 112 and proxy call session control functions (P-CSCFs) 114 and 116. PGW/HSGWs 110 and 112 provide access network services to subscriber terminals. Without the subject matter described herein, PGW/HSGWs 110 and 112 would be required to be programmed with PCRF node selection functionality for all the PCRFs in the network. Thus, each time a new PCRF was added anywhere in the network, each PGW or HSGW would have to be updated. Such a solution is not scalable, as the number of PGWs and HSGWs in a network may be large. Accordingly, PCRF selection nodes 100, 102, and 103 shield PGW/HSGWs 110 and 112 and P-CSCFs 114 and 116 from having to communicate directly with PCRFs.

[0015] P-CSCFs 114 and 116 perform proxy call session control functions for subscriber terminals and communicate with PCRF selection nodes 100, 102, and 103 via Rx interfaces. The P-CSCF is the key element in an IMS network in that the P-CSCF handles signaling for voice over IP (VoIP) calls. One function that must be performed by each P-CSCF in establishing a VoIP call is to obtain authorization from a PCRF to connect the call. Rather than having every P-CSCF programmed to select a PCRF for a given call, the subject matter described herein allows the P-CSCF to offload the functionality of selecting a PCRF for a particular call to PCRF selection nodes 100, 102, and 103.

[0016] According to one embodiment of the subject matter described herein, a PCRF selection node may select a PCRF based on a subscriber identifier, such as an international mobile station identifier (IMSI). The IMSI-based approach is a static approach in that the same IMSI will always hash to the same PCRF. In this embodiment, it is assumed that the P-CSCFs 114 and 116 can provide a subscriber's IMSI over the Rx interfaces and that PGW/HSGWs 110 and 112 provide the IMSI over the Gx and Gxx interfaces so the same user identity will be used across all policy and charging control (PCC) client interfaces (Gx, Gxx, and Rx). Each PCRF selection node 100, 102, and 103 may be configured with the same IMSI hashing function to determine which PCRF selection node is performing the actual PCRF selection. The hashing algorithm used in selecting the PCRF selection node that performs PCRF selection may be a truncation algorithm where the last seven digits of the IMSI are truncated, leaving the first three digits. Using a truncation algorithm where predetermined digits of a subscriber or mobile station identifier are used to determine which node will perform the PCRF selection may allow delegation of PCRF node selection on a geographic basis. For example, subscribers within a particular geographic region may have IMSIs with the same first three digits. As a result, PCRF selection for these nodes may be performed by a PCRF selection node/DRA that serves that particular geographic region. The subject matter described herein is not limited to performing PCRF node selection based on the IMSI. Any subscriber identifier that appears on the Gx, Gxx, and Rx interfaces may be used. In alternate implementation, the subscriber's telephone number can be used.

[0017] During session establishment over the Gx, Gxx, or Rx interface, a PCRF selection node receiving an establishment request, will, based on the IMSI in the request and the hash algorithm, either process the request and identify the PCRF to which the request should be routed or delegate the PCRF selection function to another PCRF selection node responsible for the IMSI.

[0018] If the PCRF selection node that receives a request determines that it is responsible for PCRF selection based on hashing of the IMSI, the PCRF selection node will, in response to the signaling over the Gx or Gxx interface, whichever occurs first, select a PCRF in its region based on any suitable algorithm, such as a load balancing or node availability algorithm. The subject matter described herein is not limited to performing PCRF node selection using a load balancing or node availability algorithm. In an alternate implementation, a subscriber or mobile station identifier, such as the IMSI, can also be used to select a PCRF. For example, if the first three digits of the IMSI are used to select a PCRF selection node, some or all of the remaining digits of the IMSI may be used by the PCRF selection node to select the PCRF. The PCRF selection node may also maintain local state about the selected PCRF so that selection may only be required to occur once per attachment.

[0019] Once a PCRF selection node has selected a PCRF, subsequent session establishment requests will be routed to the assigned PCRF selection node based on the IMSI. The requests will then be routed by the assigned PCRF selection node to the selected PCRF based on the PCRF selection state maintained by the assigned PCRF selection node.

[0020] Session updates and terminations may be delivered to the assigned PCRF based on a combination of destination-realm and destination-host as per RFC 3588. The destination-host or destination-realm parameter in a message may contain the identity of the PCRF handling the session. If the destination-host or destination-realm parameter in a message contains Diameter routing information that allows a node to identify the PCRF assigned to a subscriber, these parameters may be used to route the message to the proper PCRF. Upon detachment (i.e., when all Gx and Gxx sessions for the subscriber are terminated), the PCRF selection node may remove local state about the selected PCRF.

[0021] Figure 2 is a message flow diagram illustrating static PCRF node selection where PCRF node selection is performed locally by a PCRF selection node in response to UE attachment to a network according to an embodiment of the subject matter described herein. Referring to Figure 2, in line 1, a home service gateway (HSGW) 110A that serves a user terminal sends a Gxx credit control request (CCR) message to PCRF selection node 100. The CCR message may be generated by the HSGW in response to a user activating the user's mobile phone for the first time within an area served by a radio tower. In response to the user activating the user's mobile phone, the phone signals the radio tower. The radio tower signals HSGW 110A of the attachment. In the illustrated example, the core network to which the UE is attaching is assumed to be an LTE network. However, the access network components may not be LTE components. As such, the attachment procedure illustrated in Figure 2 is an evolved high rate packet data (eHRPD) attachment. Using an eHRPD attachment allows operators to incrementally upgrade to LTE components. However, the subject matter described herein is not limited to performing PCRF node selection in response to a UE attachment procedure. The PCRF selection methods and systems described herein may also be used to perform PCRF node selection when the UE attaches to the network via an LTE node, such as an eNodeB.

[0022] Once attachment occurs, HSGW 110A needs to establish a Gxx session with a local PCRF. However, rather than contacting a PCRF directly, HSGW 110A signals PCRF selection node 100, which may be implemented by a DRA local to HSGW 110A. In line 2, PCRF selection node 100 performs a hash algorithm on the IMSI in the CCR message, determines that PCRF selection node 100 should be the node that selects the PCRF, and selects PCRF 1041, based on any suitable criteria, such as load balancing, node availability, and/or the IMSI. Accordingly, in line 3, PCRF selection node 100 sends a Gxx CCR message to PCRF 1041. In line 4, PCRF 1041 queries home subscriber server (HSS) 200 to obtain the subscriber's policy. In line 5, PCRF 1041 sends a credit control answer (CCA) message to PCRF selection node 100. In line 6, PCRF selection node 100 sends a Gx CCA message to HSGW 110A.

[0023] In line 7, packet gateway (PGW) 110B sends a CCR message over the Gx interface to PCRF selection node 100. PGW 110B may generate the CCR message to establish a Gx session for the subscriber with the assigned PCRF. However, rather than communicating directly with the assigned PCRF, PGW 110B, which does not know which PCRF has been assigned, contacts its local DRA/PCRF selection node 100. In line 8, PCRF selection node 100 determines that PCRF 1041 has already been selected for the IMSI in the CCR message and, in line 9, sends a CCR message to the selected PCRF 1041. In line 10, PCRF 1041 sends a Gx CCA message to PCRF selection node 100. In line 11, PCRF selection node 100 sends a Gx CCA message to packet gateway 110B.

[0024] Figure 3 is a message flow diagram illustrating static PCRF selection where the PCRF selection is delegated according to an embodiment of the subject matter described herein. Referring to Figure 3, when a UE attaches to the network, in line 1, HS gateway 110A sends a CCR message over the Gx interface to PCRF selection node 100. In line 2, PCRF selection node 100 performs a hash function on the IMSI in the CCR message and determines that PCRF selection node 100 is not the node that is assigned to select the PCRF. As set forth above, PCRF selection node 100 may determine that the subscriber's IMSI is local to another PCRF selection node. In this example, the PCRF selection node local to the IMSI (i.e., the subscriber's home PCRF selection node) is assumed to be PCRF selection node 102. Accordingly, PCRF selection node 100 sends a CCR message to PCRF selection node 102, delegating the PCRF node selection. In line 4, PCRF selection node 102 determines, based on the IMSI, that PCRF selection node 102 is the PCRF selection node assigned to select the PCRF and selects PCRF 1061, based on any suitable criteria, such as load balancing, node availability, and/or a subscriber identifier in the message. In line 5, PCRF selection node 102 sends a CCR message to the selected PCRF 1061. In line 6, PCRF 1061 obtains the subscriber's policy from HSS 200. In line 7, PCRF 1061 sends a CCA message to PCRF selection node 102. In line 8, PCRF selection node 102 sends a CCA message to PCRF selection node 100. In line 9, PCRF selection node 100 sends a CCA message to HS gateway 110A. The response CCA messages may follow the same paths as the corresponding requests using standard Diameter routing.

[0025] In line 10 of the message flow diagram, packet gateway 110B sends a CCR message to PCRF selection node 100 to initiate a Gx session for the subscriber. In line 11, PCRF selection node 100 performs the hash function based on the IMSI in the CCR message and determines that the CCR message should be routed to PCRF selection node 102. In line 12, PCRF selection node 100 sends a CCR message to PCRF selection node 102. In line 13, PCRF selection node 102 determines that PCRF 1061 has already been selected for the IMSI. Accordingly, in line 14, PCRF selection node 102 sends a CCR message to the selected PCRF 1061. In line 15, PCRF 1061 sends a CCA message to PCRF selection node 102. In line 16, PCRF selection node 102 sends a CCA message to PCRF selection node 100. In line 17, PCRF selection node 100 sends a CCA message to packet gateway 110B.

[0026] Figure 4 is a message flow diagram illustrating exemplary messages exchanged for establishment of an application function (AF) session where a PCRF was selected using the method illustrated in Figure 2 according to an embodiment of the subject matter described herein. Referring to Figure 4, it is assumed that a UE is attached to the network and that PCRF selection node 100 selected PCRF 1041 to serve the UE, as illustrated in Figure 2. In line 1 of the message flow diagram illustrated in Figure 4, an AF 400 sends an AA request (AAR) message to PCRF selection node 100 to establish an AF session with the PCRF assigned to the subscriber. AF 400 may be a web server, a video server, or a P-CSCF that seeks to establish a session with a user. Rather than communicating directly with a PCRF, application function 400 may communicate with its local DRA/PCRF selection node 100. In line 2, PCRF selection node 100 determines, using its stored PCRF selection state, that PCRF 1041 has already been selected for the IMSI received in the AAR message. Accordingly, in line 3, PCRF selection node 100 sends an AAR message over the Rx interface to PCRF 1041. In line 4, PCRF 1041 sends an AA answer (AAA) message to PCRF selection node 100 over the Rx interface. In line 5, PCRF selection node 100 sends an AAA message to AF 400 over the Rx interface.

[0027] Figure 5 is a message flow diagram illustrating exemplary messaging for establishment of an AF session where PCRF selection was delegated during UE attachment. Referring to Figure 5, it is assumed that PCRF selection node 102 select PCRF 1061 for the subscriber using the method illustrated in Figure 3. In line 1 of the message flow diagram in Figure 5, AF 400 sends an AAR message over the Rx interface to PCRF selection node 100 to initiate the AF session. PCRF selection node 100 does not store PCRF selection state because PCRF selection node 100 did not select the PCRF for this particular subscriber. Accordingly, in line 2, PCRF selection node 100 determines that the AAR message should be routed to PCRF selection node 102 based on the IMSI in the AAR message. In line 3, PCRF selection node 100 sends an AAR message over the Rx interface to PCRF selection node 102. PCRF selection node 102 is the node that performs the PCRF selection and stores PCRF selection state for the IMSI. Accordingly, in line 4 of the message flow diagram, PCRF selection node 102 determines that PCRF 1061 has already been selected for the IMSI. In line 5, PCRF selection node 102 sends an AAR message to the selected PCRF 1061. In line 6, PCRF 1061 sends an AAA message to PCRF selection node 102. In line 7, PCRF selection node 102 sends an AAA message to PCRF selection node 100. In line 8, PCRF selection node 100 sends an AAA message to AF 400.

[0028] According to another embodiment of the subject matter described herein, dynamic PCRF node selection is provided. According to dynamic PCRF selection, the node that performs PCRF node selection is determined based on dynamic criteria, such as load balancing and/or node availability, rather than based on static criteria, such as the IMSI. Once a PCRF selection node has been assigned and has selected a PCRF, the PCRF selection node may store its identity and/or the identity of the selected PCRF in a database node, such as an HSS. Other PCRF selection nodes can retrieve the selected PCRF information from the database node. According to this embodiment, during session establishment over the Gx, Gxx, or Rx interfaces, a PCRF selection node that receives a session establishment request will determine whether the receiving PCRF selection node or another PCRF selection node will be responsible for selecting the PCRF handling the session. In contrast to the static embodiment described above where the decision as to whether to select the PCRF locally or delegate the selection is based on static criteria, in this embodiment, the determination as to whether to perform such delegation may be based on dynamic criteria, such as load balancing and/or node availability. In such an embodiment, assignment of a PCRF selection node and/or a PCRF based on home or geographic indicators associated with a subscriber identifier may be avoided. Instead, the selection of a PCRF selection node to perform the PCRF node selection and selection of the corresponding PCRF may be done based on domains of responsibility that may be assigned by the network operator.

[0029] If a PCRF selection node that receives a session establishment request has already selected a PCRF for the user, it will route the request to the selected PCRF. Otherwise, it will query the HSS or other database to determine if a PCRF has already been selected. If the result of the query indicates that a PCRF has already been selected, the PCRF selection node will route the request to the PCRF via the PCRF's DRA / PCRF selection node. If a PCRF was not previously selected, the PCRF selection node will dynamically determine (e.g., using load balancing and/or node availability information) a PCRF selection node that will be responsible for PCRF selection and will route the request to that node. The request to the receiving PCRF selection node may include a token or parameter that indicates to the receiving PCRF selection node that it is the last node in a hierarchy of PCRF selection nodes and that the PCRF selection node should perform, rather than delegate, the PCRF selection. The PCRF selection node that receives the request will select the PCRF and write the HSS or other database its identity and optionally the identity of the selected PCRF. The PCRF selection node that performed the selection may store the identity of the selected PCRF locally to shield the HSS or other database from subsequent queries to determine the assigned PCRF.

[0030] As stated above, a PCRF selection node may perform PCRF selection within its domain of responsibility using a load balancing and/or node availability algorithm. The PCRF selection node may maintain local state about the local PCRF to minimize interaction with the HSS. Session updates and terminations may be delivered to the proper PCRF based on a combination of destination-realm and destination-host, as specified in RFC 3588. The destination-host parameter in a message may contain the identity of the PCRF handling this session. Upon detachment (i.e., when all Gx and Gxx session for subscriber are terminated) the PCRF selection node may delete the selected PCRF and/or DRA/PCRF selection node data in the HSS and remove the corresponding local state.

[0031] Figure 6 is a message flow diagram illustrating dynamic PCRF selection where a PCRF is selected locally by a DRA/PCRF selection node that receives a Diameter session establishment request in response to user attachment to a network according to an embodiment of the subject matter described herein. Referring to Figure 6, it is assumed that user equipment attaches to the network and, in line 1, HS gateway 110A sends a CCR message over the Gxx interface to PCRF selection node 100 to initiate establishment of a Gxx session for the user. PCRF selection node 100 determines in line 2 that it does not store information indicating that a PCRF has been selected for the UE. Accordingly, in line 3, PCRF selection node 100 queries HSS 200 to determine whether a PCRF has been selected. As set forth above, the subject matter described herein is not limited to storing PCRF selection state in an HSS. Any suitable centralized database accessible by DRA/PCRF selection nodes to store and access PCRF selection information is intended to be within the scope of the subject matter described herein. In an alternate implementation, which will be described in detail below, PCRF selection state may be maintained by a node that is dedicated to storing PCRF selection state, referred to as a subscription binding repository (SBR). In the embodiment illustrated in Figure 6, it is assumed that once PCRF selection has occurred, the selection state is stored in HSS 200.

[0032] In line 4, PCRF selection node 100 determines that no PCRF has been selected, so PCRF selection node 100 dynamically determines that PCRF selection node 100 is the PCRF selection node responsible for selecting the PCRF and selects PCRF selection node 1041. As set forth above, the determination as to whether to perform PCRF selection locally may be based on dynamic criteria, such as load balancing and/or node availability. Other dynamic criteria that may be used may include PCRF selection delegation token in a message received from another DRA/PCRF selection node.

[0033] In line 5, PCRF selection node 100 sends a CCR message to the selected PCRF 1041 over the Gxx interface. In line 6, the selected PCRF 1041 queries HSS 200 to obtain a policy for the subscriber. In line 7, PCRF node 1041 sends a CCA message to PCRF selection node 100 over the Gxx interface. In line 8, PCRF selection node 100 writes the identifier of the selected PCRF for the user equipment to HSS 200. As set forth above, it may not be necessary for the identifier of selected PCRF to be written to the HSS. In an alternate implementation, only the identifier of the PCRF selection node/DRA that performs the selection may be written to the HSS. Since the PCRF selection node/DRA that performs the selection stores the PCRF selection state, subsequent queries to the HSS will yield the PCRF selection node/DRA, and the PCRF selection node/DRA will route the signaling to the proper PCRF. In line 9, PCRF selection node 100 sends a CCA message to HS gateway 110A. In line 10, packet gateway 110B sends a CCR message to PCRF selection node 100 to establish a Gx session for the UE. In line 11, PCRF selection node 100 determines whether a PCRF has already been selected by PCRF selection node 100 for the UE. Because PCRF 1041 has already been selected by PCRF selection node 100, in line 12, PCRF selection node 100 sends a CCR message to PCRF 1041 over the Gx interface. In line 13, PCRF 1041 sends a CCA message to PCRF selection node 100 over the Gx interface. In line 14, PCRF selection node 100 sends a Gx CCA message to packet gateway 110B.

[0034] Figures 7A and 7B are a message flow diagram illustrating exemplary messages exchanged for dynamic PCRF selection where PCRF selection is delegated from one PCRF selection node/DRA to another PCRF selection node/DRA according to an embodiment of the subject matter described herein. Referring to Figure 7A, it is assumed that a UE attaches to the network via an access network within the domain of responsibility of HSGW 110A. According, in line 1, HS gateway 110A sends a CCR message to PCRF selection node 100 via the Gxx interface to establish a Gx session for the UE. In line 2, PCRF selection node 100 determines whether PCRF selection node 100 has information that indicates that a PCRF has been selected for a session. No information is determined to be present in this example, so in line 3, PCRF selection node 100 queries HSS 200 to determine whether a PCRF has been assigned. In line 4, PCRF selection node 100 determines, based on the response from HSS 200, that no PCRF has been selected. Accordingly, PCRF selection node 100 performs a load balancing or other suitable algorithm and selects PCRF selection node 102 to perform the PCRF selection. Accordingly, in line 5, PCRF selection node 100 sends a CCR message to PCRF selection node 102. As set forth above, the CCR message may include a PCRF selection delegation token that indicates to PCRF selection node 102 that PCRF selection node 102 is to perform the PCRF selection, rather than delegate the PCRF selection to another node. In line 6, PCRF selection node 102 performs PCRF selection using a load balancing or other suitable algorithm to select PCRF node 1061. In line 7, PCRF selection node 102 sends a CCR message to the selected PCRF 1061. In line 8, PCRF 1061 queries HSS 200 to obtain a policy for the subscriber.

[0035] Referring to Figure 7B, in line 10, PCRF selection node 102 writes the identity of the selected PCRF and/or the identity of PCRF selection node 102 to HSS 200. In line 11, PCRF selection node 102 sends a CCA message to PCRF selection node 100 over the Gxx interface. In line 12, PCRF selection node sends a CCA message to HS gateway 110A over the Gxx interface.

[0036] In line 13, PGW 110B sends a CCR message to PCRF selection node 100 to establish a Gx session for the UE. In line 14, PCRF selection node 100 determines whether a PCRF has already been selected for this session. In this example, PCRF selection node 100 does not know whether a PCRF has been selected, because PCRF selection node 100 did not perform the selection and store the selection state locally. Accordingly, PCRF selection node 100 sends a PCRF selection query to HSS 200. In line 16, PCRF selection node 100 determines, from the response from the HSS 200, that PCRF 1061 is selected and determines that the CCR message should be routed to PCRF 1061 via PCRF selection node 102. In line 17, PCRF selection node 100 sends a CCR message to PCRF selection node 102 via the Gx interface. In line 18, PCRF selection node 102 determines, using locally stored PCRF selection state, that PCRF 1061 has already been selected for the UE. Accordingly, in line 19, PCRF selection node 102 sends a CCR message to the selected PCRF 1061. In line 20, PCRF 1061 sends a CCA message to PCRF selection node 102 over the Gx interface. In line 21, PCRF selection node 102 sends a CCA message to PCRF selection node 100 over the Gx interface. In line 22, PCRF selection node 100 sends a CCA message to PGW 110B over the Gx interface.

[0037] Figure 8 is a message flow diagram illustrating assignment of PCRF to an AF session where the PCRF was previously dynamically selected using the method illustrated in Figure 6 according to an embodiment of the subject matter described herein. Referring to Figure 8, it is assumed that a UE has attached to the network and PCRF 1041 has been selected by PCRF selection node 100, as illustrated in Figure 6. In line 1 of Figure 8, AF 400 sends an AAR message to PCRF selection node 100. In line 2, PCRF selection node 100 determines, using locally stored PCRF selection state, that PCRF 1041 has already been selected for this session. Accordingly, in line 3, PCRF selection node 100 sends an AAR message over the Rx interface to the selected PCRF 1041. In line 4, PCRF 1041 sends an AAA message over the Rx interface to PCRF selection node 100. In line 5, PCRF selection node 100 sends an AAA message to application function 400.

[0038] Figure 9 is a message flow diagram illustrating assignment of PCRF to an AF session where the PCRF was previously dynamically selected using the method illustrated in Figure 6. However, unlike the example illustrated in Figure 8, the PCRF selection node that receives the initial AAR message in Figure 9 is not the PCRF selection node that performed the PCRF selection. In Figure 9, it is assumed that a PCRF 1041 and PCRF selection node 100 have been selected using the method set forth in Figure 6. Accordingly, in line 1, AF 400 sends an AAR message to PCRF selection node 102. In line 2, PCRF selection node 102 determines that PCRF selection node 102 does not have any local state information indicating that a PCRF selection has occurred. Accordingly, in line 3, PCRF selection node 102 queries HSS 200 for the selected PCRF information. In line 4, PCRF selection node 102 determines that PCRF 1041 has been selected and that the request should be routed to PCRF 1041 via PCRF selection node 100. In line 5, PCRF selection node 102 sends an AAR message to PCRF selection node 100. In line 6, PCRF selection node 100 determines, using locally stored PCRF selection state, that PCRF 1041 is already selected for the UE. In line 7, PCRF selection node 100 sends an AAR message to PCRF 1041. In line 8, PCRF 1041 sends an AAA message to PCRF selection node 100. In line 9, PCRF selection node 100 sends an AAR message to PCRF selection node 102. In line 10, PCRF selection node 102 sends an AAA message to AF 400.

[0039] Figure 10 is a flow chart illustrating exemplary overall steps for PCRF node selection according to an embodiment of the subject matter described herein. Referring to Figure 10, in step 1000, a request for which PCRF node selection is required is received at a first PCRF selection node. In step 1002, the first PCRF selection node determines whether to select the PCRF locally or to delegate the selection. If the first PCRF selection node determines to select the PCRF locally, control proceeds to step 1004 where the first PCRF selection node selects the PCRF locally. The determination as to whether to select the PCRF locally or to delegate the PCRF selection may be determined statically, using the IMSI, as described above, or dynamically, based on dynamic criteria, as described above.

[0040] Returning to step 1002, if the first PCRF selection node determines to delegate the PCRF selection, control proceeds to step 1006 where the first PCRF selection node sends a second request message related to the first request message to a second PCRF selection node. The second PCRF node may execute the same algorithm illustrated in Figure 10 to determine whether it should select the PCRF or delegate the selection.

[0041] Figure 11 is block diagram illustrating an exemplary PCRF selection node according to an embodiment of the subject matter described herein. Referring to Figure 11, PCRF selection node 100, 102, or 103 includes a communications interface 1100 for receiving request messages for which PCRF selection is indicated. The request messages may be CCR message and they may arrive over any suitable interface, such as the Gx or the Gxx interfaces. For application originated sessions, the messages may be AAR messages that arrive over the Rx interface. PCRF selection node 100, 102, or 103 may include a PCRF selection module 1102 that performs local or delegates PCRF selection as described above. PCRF selection nodes 100, 102, or 103 may also store PCRF selection state information 1104 to avoid unnecessary contact with HSS nodes to obtain PCRF selection information. As set forth above, PCRF selection node 100, 102, or 103 may be dedicated to performing PCRF node selection or may include diameter routing agent (DRA) functionality. As such, PCRF selection node 100, 102, or 103 may include a Diameter routing table 1106 that contains information for routing diameter signaling messages sent by Diameter parameters, such as destination-realm and destination-host.

[0042] Figure 12 illustrates an embodiment of the subject matter described herein where PCRF selection state information is stored in a database separate from the HSS and from the DRA. Referring to Figure 12, a node that is dedicated to storing PCRF selection state, referred to as a subscription binding repository (SBR) 1200, stores PCRF selection state information. SBR 1200 can be updated with PCRF selection state using any of the methods used herein. For example, PCRF selection nodes 100 or 102 can select the PCRF statically based on the IMSI, as described above or dynamically, using load balancing, as described above. The PCRF selection state may be written to SBR 1200. In an alternate implementation, PCRF selection nodes 100 and 102 may select one of front end nodes 1204 and 1206, and front end nodes 1204 and 1206 may perform the PCRF selection based on load balancing or other suitable criteria. Front end nodes 1204 and 1206 may be dedicated to performing PCRF node selection. Alternatively, front end nodes 1204 and 1206 may also include DRA functionality, similar to PCRF selection nodes 100 and 102. Once a PCRF is selected, that information will be stored in SBR 1200. Storing PCRF selection information in SBR 1200 allows SBR 1200 to be queried to obtain PCRF selection state and further offloads traffic and processing from the HSS and the DRA. In addition, SBRs may be arranged in a hierarchy such that each SBR stores PCRF selection state for its domain of responsibility and forwards PCRF-related queries requests to peers when an SBR does not have the selection state to provide in response to a query but knows of a peer SBR that might have the PCRF selection state.


Claims

1. A system for a policy charging and rules function, PCRF, node (104, 106, 108) selection, the system comprising:

a first PCRF selection node (100) for receiving a first request message for which PCRF node selection is required, for determining whether to select a PCRF node (104, 106, 108) or to delegate selection of the PCRF node (104, 106, 108), and, in response to determining to delegate selection of the PCRF node (104, 106, 108), for generating and sending a second request message based on the first request message; and

a second PCRF selection node (102) for, in response to receiving the second request message from the first PCRF selection node (100), for determining whether to select the PCRF node (104, 106, 108), and, in response to determining to select the PCRF node (104, 106, 108), for selecting the PCRF node (104, 106, 108);

wherein the second PCRF selection node (102), in response to selecting the PCRF node (104, 106, 108), is configured to write information indicating at least one of: an identity of the selected PCRF (104, 106, 108) and an identity of the second PCRF selection node (102) to a database node (1200);
wherein the database node (1200) comprises a subscription binding repository, SBR (1200), that is configured as part of an SBR hierarchy for providing PCRF selection information in response to queries for PCRFs within a domain of responsibility of the SBR (1200); and
wherein the second request message comprises a token or parameter that indicates to the second PCRF selection node (102) that it is the last node in a hierarchy of PCRF selection nodes and that the second PCRF selection node (102) should perform, rather than delegate, the PCRF selection.
 
2. The system of claim 1 wherein the first PCRF selection node (100) is configured to determine whether to select the PCRF node (104, 106, 108) based on a subscriber identifier in the first request message, a hash of the subscriber identifier, or dynamic criteria, including load balancing criteria or node availability criteria.
 
3. The system according to claim 1 or 2, wherein the SBR (1200) is configured to forward SBR queries to other SBRs in the SBR hierarchy when the queries request information outside of the domain of responsibility of the SBR (1200).
 
4. The system of claim 1 wherein the first and second PCRF selection nodes (100, 102) are dedicated to performing PCRF node (104, 106, 108) selection or additionally include diameter relay agent, DRA, functionality.
 
5. A method for policy charging and rules function, PCRF, node (104, 106, 108) selection, the method comprising:

at a first PCRF selection node (100):

receiving a first request message for which PCRF node (104, 106, 108) selection is required;

determining whether to select a PCRF node (104, 106, 108) or to delegate selection of the PCRF node (104, 106, 108); and

in response to determining to delegate selection of the PCRF node (104, 106, 108), generating and sending a second request message based on the first request message; and

at a second PCRF selection node (102):

in response to receiving the second request message from the first PCRF selection node (100);

determining whether to select the PCRF node (104, 106, 108); and

in response to determining to select the PCRF node (104, 106, 108), for selecting the PCRF node;

wherein the second PCRF selection node (102), in response to selecting the PCRF (104, 106, 108), writes information indicating at least one of: an identity of the selected PCRF (104, 106, 108) and an identity of the second PCRF selection node (102) to a database node (1200);
wherein the database node (1200) comprises a subscription binding repository, SBR (1200), that is configured as part of an SBR hierarchy for providing PCRF selection information in response to queries or PCRFs within a domain of responsibility of the SBR (1200); and
wherein the second request message comprises a token or parameter that indicates to the second PCRF selection node (102) that it is the last node in a hierarchy of PCRF selection nodes and that the second PCRF selection node (102) should perform, rather than delegate, the PCRF selection.
 
6. The method of claim 5 wherein the first PCRF selection node (100) determines whether to select the PCRF node (104, 106, 108) based on a subscriber identifier in the first request message, a hash of the subscriber identifier, or dynamic criteria, including load balancing criteria or node availability criteria.
 
7. The method of claim 5 or 6, wherein the SBR (1200) is configured to forward SBR queries to other SBRs in the SBR hierarchy when the queries request information outside of the domain of responsibility of the SBR (1200).
 
8. The method of claim 5 wherein the first and second PCRF selection nodes (100, 102) are dedicated to performing PCRF node selection or additionally include diameter relay agent, DRA, functionality.
 
9. A computer readable medium having stored thereon executable instructions that when executed by the processor of a computer control the computer to perform the method of any one of claims 5 to 8.
 


Ansprüche

1. System für eine Richtliniengebührenerhebungs- und Regelnfunktions- (Policy Charging and Rules Function - PCRF) Knoten- (104, 106, 108) Auswahl, wobei das System Folgendes umfasst:

einen ersten PCRF-Auswahlknoten (100) zum Empfang einer ersten Anforderungsnachricht, für die eine PCRF-Knotenauswahl erforderlich ist, um zu bestimmen, ob ein PCRF-Knoten (104, 106, 108) auszuwählen ist oder eine Auswahl des PCRF-Knotens (104, 106, 108) zu delegieren ist, und als Reaktion auf die Bestimmung, dass eine Auswahl des PCRF-Knotens (104, 106, 108) zu delegieren ist, zum Erzeugen und Senden einer zweiten Anforderungsnachricht basierend auf der ersten Anforderungsnachricht; und

einen zweiten PCRF-Auswahlknoten (102) zum Bestimmen, als Reaktion auf den Empfang der zweiten Anforderungsnachricht von dem ersten PCRF-Auswahlknoten (100), ob der PCRF-Knoten (104, 106, 108) auszuwählen ist, und als Reaktion auf die Bestimmung der Auswahl des PCRF-Knotens (104, 106, 108), zum Auswählen des PCRF-Knotens (104, 106, 108);

wobei der zweite PCRF-Auswahlknoten (102) als Reaktion auf die Auswahl des PCRF-Knotens (104, 106, 108) dafür konfiguriert ist, Informationen, die mindestens eine Identität des ausgewählten PCRF (104, 106, 108) und eine Identität des zweiten PCRF-Auswahlknotens (102) anzeigen, in einen Datenbankknoten (1200) zu schreiben;
wobei der Datenbankknoten (1200) einen Abonnementbindungsspeicher (Subscription Binding Repository - SBR) (1200) umfasst, der als Teil einer SBR-Hierarchie konfiguriert ist, um PCRF-Auswahlinformationen als Reaktion auf Abfragen nach PCRFs innerhalb einer Verantwortsdomäne des SBR (1200) bereitzustellen; und
wobei die zweite Anforderungsnachricht einen Token oder Parameter enthält, der dem zweiten PCRF-Auswahlknoten (102) anzeigt, dass er der letzte Knoten in einer Hierarchie von PCRF-Auswahlknoten ist und dass der zweite PCRF-Auswahlknoten (102) die PCRF-Auswahl ausführen sollte, anstatt sie zu delegieren.
 
2. System nach Anspruch 1, wobei der erste PCRF-Auswahlknoten (100) dafür konfiguriert ist, zu bestimmen, ob der PCRF-Knoten (104, 106, 108) basierend auf Folgendem auszuwählen ist: einer Teilnehmerkennung in der ersten Anforderungsnachricht, einem Hash der Teilnehmerkennung oder dynamischen Kriterien, die Lastausgleichskriterien oder Knotenverfügbarkeitskriterien umfassen.
 
3. System nach Anspruch 1 oder 2, wobei der SBR (1200) dafür konfiguriert ist, SBR-Abfragen an andere SBRs in der SBR-Hierarchie weiterzuleiten, wenn die Abfragen Informationen außerhalb der Verantwortungsdomäne des SBR (1200) anfordern.
 
4. System nach Anspruch 1, wobei der erste und zweite PCRF-Auswahlknoten (100, 102) der Durchführung einer PCRF-Knoten- (104, 106, 108) Auswahl gewidmet sind oder zusätzlich Durchmesserweiterleitungsagenten- (Diameter Relay Agent - DRA) Funktionalität umfassen.
 
5. Verfahren für eine Richtliniengebührenerhebungs- und Regelnfunktions-, PCRF-, Knoten- (104, 106, 108) Auswahl, wobei das Verfahren Folgendes umfasst:

bei einem ersten PCRF-Auswahlknoten (100):

Empfangen einer ersten Anforderungsnachricht, für die eine PCRF-Knoten- (104, 106, 108) Auswahl erforderlich ist;

Bestimmen, ob ein PCRF-Knoten (104, 106, 108) auszuwählen ist oder eine Auswahl des PCRF-Knotens (104, 106, 108) zu delegieren ist, und

als Reaktion auf die Bestimmung, dass eine Auswahl des PCRF-Knotens (104, 106, 108) zu delegieren ist, Erzeugen und Senden einer zweiten Anforderungsnachricht basierend auf der ersten Anforderungsnachricht; und

bei einem zweiten PCRF-Auswahlknoten (102):

als Reaktion auf den Empfang der zweiten Anforderungsnachricht von dem ersten PCRF-Auswahlknoten (100):

Bestimmen, ob der PCRF-Knoten (104, 106, 108) auszuwählen ist und

als Reaktion auf die Bestimmung der Auswahl des PCRF-Knotens (104, 106, 108), zum Auswählen des PCRF-Knotens;

wobei der zweite PCRF-Auswahlknoten (102) als Reaktion auf die Auswahl des PCRF (104, 106, 108) Informationen, die mindestens eine Identität des ausgewählten PCRF (104, 106, 108) und eine Identität des zweiten PCRF-Auswahlknotens (102) anzeigen, in einen Datenbankknoten (1200) schreibt;
wobei der Datenbankknoten (1200) einen Abonnementbindungsspeicher (Subscription Binding Repository - SBR) (1200) umfasst, der als Teil einer SBR-Hierarchie konfiguriert ist, um PCRF-Auswahlinformationen als Reaktion auf Abfragen nach PCRFs innerhalb einer Verantwortsdomäne des SBR (1200) bereitzustellen; und
wobei die zweite Anforderungsnachricht einen Token oder Parameter enthält, der dem zweiten PCRF-Auswahlknoten (102) anzeigt, dass er der letzte Knoten in einer Hierarchie von PCRF-Auswahlknoten ist und dass der zweite PCRF-Auswahlknoten (102) die PCRF-Auswahl ausführen sollte, anstatt sie zu delegieren.
 
6. Verfahren nach Anspruch 5, wobei der erste PCRF-Auswahlknoten (100) bestimmt, ob der PCRF-Knoten (104, 106, 108) basierend auf Folgendem auszuwählen ist: einer Teilnehmerkennung in der ersten Anforderungsnachricht, einem Hash der Teilnehmerkennung oder dynamischen Kriterien, die Lastausgleichskriterien oder Knotenverfügbarkeitskriterien umfassen.
 
7. Verfahren nach Anspruch 5 oder 6, wobei der SBR (1200) dafür konfiguriert ist, SBR-Abfragen an andere SBRs in der SBR-Hierarchie weiterzuleiten, wenn die Abfragen Informationen außerhalb der Verantwortungsdomäne des SBR (1200) anfordern.
 
8. Verfahren nach Anspruch 5, wobei der erste und zweite PCRF-Auswahlknoten (100, 102) der Durchführung einer PCRF-Knotenauswahl gewidmet sind oder zusätzlich Durchmesserweiterleitungsagenten- (Diameter Relay Agent - DRA) Funktionalität umfassen.
 
9. Computerlesbares Medium, auf dem ausführbare Anweisungen gespeichert sind, die, wenn sie von einem Prozessor eines Computers ausgeführt werden, den Computer so steuern, dass er das Verfahren nach einem der Ansprüche 5 bis 8 durchführt.
 


Revendications

1. Système pour la sélection de noeuds de la PCRF (policy charging and rules function - fonction de règles de politique et de facturation) (104, 106, 108), le système comportant :

un premier noeud de sélection de la PCRF (100) pour recevoir un premier message de requête pour lequel une sélection de noeud de la PCRF est requise, pour déterminer s'il faut sélectionner un noeud de la PCRF (104, 106, 108) ou s'il faut déléguer la sélection du noeud de la PCRF (104, 106, 108), et, en réponse à la détermination comme quoi il faut déléguer la sélection du noeud de la PCRF (104, 106, 108), pour générer et envoyer un deuxième message de requête en fonction du premier message de requête ; et

un deuxième noeud de sélection de la PCRF (102) pour, en réponse à la réception du deuxième message de requête en provenance du premier noeud de sélection de la PCRF (100), déterminer s'il faut sélectionner le noeud de la PCRF (104, 106, 108), et, en réponse à la détermination comme quoi il faut sélectionner le noeud de la PCRF (104, 106, 108), pour sélectionner le noeud de la PCRF (104, 106, 108) ;

dans lequel le deuxième noeud de sélection de la PCRF (102), en réponse à la sélection du noeud de la PCRF (104, 106, 108), est configuré pour écrire des informations indiquant au moins l'une parmi : une identité de la PCRF sélectionnée (104, 106, 108) et une identité du deuxième noeud de sélection de la PCRF (102) à destination d'un noeud de base de données (1200) ;
dans lequel le noeud de base de données (1200) comporte un SBR (subscription binding repository - référentiel d'association des abonnements) (1200), qui est configuré comme faisant partie d'une hiérarchie de SBR pour fournir des informations de sélection de la PCRF en réponse à des requêtes de PCRF dans les limites d'un domaine de responsabilité du SBR (1200) ; et
dans lequel le deuxième message de requête comporte un jeton ou un paramètre qui indique au deuxième noeud de sélection de la PCRF (102) qu'il est le dernier noeud dans une hiérarchie de noeuds de sélection de la PCRF et que le deuxième noeud de sélection de la PCRF (102) doit effectuer, plutôt que déléguer, la sélection de la PCRF.
 
2. Système selon la revendication 1, dans lequel le premier noeud de sélection de la PCRF (100) est configuré pour déterminer s'il faut sélectionner le noeud de la PCRF (104, 106, 108) en fonction d'un identifiant d'abonné dans le premier message de requête, d'une empreinte numérique de l'identifiant d'abonné, ou de critères dynamiques, comprenant des critères d'équilibrage de charge ou des critères de disponibilité de noeuds.
 
3. Système selon la revendication 1 ou la revendication 2, dans lequel le SBR (1200) est configuré pour transférer des requêtes de SBR à d'autres SBR dans la hiérarchie de SBR quand les requêtes demandent des informations hors du domaine de responsabilité du SBR (1200).
 
4. Système selon la revendication 1, dans lequel les premier et deuxième noeuds de sélection de la PCRF (100, 102) sont spécialisés pour effectuer une sélection de noeud de la PCRF (104, 106, 108) ou pour en outre inclure une fonctionnalité DRA (diameter relay agent - agent de relais Diameter).
 
5. Procédé pour la sélection de noeuds de la PCRF (policy charging and rules function - fonction de règles de politique et de facturation) (104, 106, 108), le procédé comportant :

au niveau d'un premier noeud de sélection de la PCRF (100) :

l'étape consistant à recevoir un premier message de requête pour lequel une sélection de noeud de la PCRF (104, 106, 108) est requise ;

l'étape consistant à déterminer s'il faut sélectionner un noeud de la PCRF (104, 106, 108) ou s'il faut déléguer la sélection du noeud de la PCRF (104, 106, 108) ; et,

en réponse à la détermination comme quoi il faut déléguer la sélection du noeud de la PCRF (104, 106, 108), l'étape consistant à générer et à envoyer un deuxième message de requête en fonction du premier message de requête ; et

au niveau d'un deuxième noeud de sélection de la PCRF (102) :

en réponse à la réception du deuxième message de requête en provenance du premier noeud de sélection de la PCRF (100) ;

l'étape consistant à déterminer s'il faut sélectionner le noeud de la PCRF (104, 106, 108) ; et

en réponse à la détermination comme quoi il faut sélectionner le noeud de la PCRF (104, 106, 108), l'étape consistant à sélectionner le noeud de la PCRF ;

dans lequel le deuxième noeud de sélection de la PCRF (102), en réponse à la sélection de la PCRF (104, 106, 108), écrit des informations indiquant au moins l'une parmi : une identité de la PCRF sélectionnée (104, 106, 108) et une identité du deuxième noeud de sélection de la PCRF (102) à destination d'un noeud de base de données (1200) ;
dans lequel le noeud de base de données (1200) comporte un SBR (subscription binding repository - référentiel d'association des abonnements) (1200), qui est configuré comme faisant partie d'une hiérarchie de SBR pour fournir des informations de sélection de la PCRF en réponse à des requêtes de PCRF dans les limites d'un domaine de responsabilité du SBR (1200) ; et
dans lequel le deuxième message de requête comporte un jeton ou un paramètre qui indique au deuxième noeud de sélection de la PCRF (102) qu'il est le dernier noeud dans une hiérarchie de noeuds de sélection de la PCRF et que le deuxième noeud de sélection de la PCRF (102) doit effectuer, plutôt que déléguer, la sélection de la PCRF.
 
6. Procédé selon la revendication 5, dans lequel le premier noeud de sélection de la PCRF (100) détermine s'il faut sélectionner le noeud de la PCRF (104, 106, 108) en fonction d'un identifiant d'abonné dans le premier message de requête, d'une empreinte numérique de l'identifiant d'abonné, ou de critères dynamiques, comprenant des critères d'équilibrage de charge ou des critères de disponibilité de noeuds.
 
7. Procédé selon la revendication 5 ou la revendication 6, dans lequel le SBR (1200) est configuré pour transférer des requêtes de SBR à d'autres SBR dans la hiérarchie de SBR quand les requêtes demandent des informations hors du domaine de responsabilité du SBR (1200).
 
8. Procédé selon la revendication 5, dans lequel les premier et deuxième noeuds de sélection de la PCRF (100, 102) sont spécialisés pour effectuer une sélection de noeud de la PCRF ou pour en outre inclure une fonctionnalité DRA (diameter relay agent - agent de relais Diameter).
 
9. Support lisible par un ordinateur ayant, stockées sur celui-ci, des instructions exécutables qui, quand elles sont exécutées par le processeur d'un ordinateur, commandent à l'ordinateur d'effectuer le procédé selon l'une quelconque des revendications 5 à 8.
 




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Cited references

REFERENCES CITED IN THE DESCRIPTION



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Patent documents cited in the description




Non-patent literature cited in the description