WO2010091734A1

WO2010091734A1 - Policy control enhancement for service continuity

Info

Publication number: WO2010091734A1
Application number: PCT/EP2009/051723
Authority: WO
Inventors: Mirko Schramm
Original assignee: Nokia Siemens Networks Oy
Priority date: 2009-02-13
Filing date: 2009-02-13
Publication date: 2010-08-19

Abstract

A system comprises a proxy call state control function (16; 26; 36) in operable connection with a policy and charging rules function (172; 272; 372). The proxy call state control function (16; 26; 36) is configured to control a communication session signaling, to detect (4) that the communication session signaling relates to an ongoing service, and to indicate (5) the ongoing service to the policy and charging rules function (172; 272; 372). The policy and charging rules function (172; 272; 372) is configured to check (6a) a request for communication resources for information about an ongoing service, and to prefer (6b) authorization of communication resources for an ongoing service over authorization of communication resources for a new service.

Description

Policy Control Enhancement for Service Continuity

Field of the Invention

The present invention relates to an apparatus, method, system and computer program product for enhancing service continuity.

Related background Art

Prior art which is related to this technical field can e.g. be found by the technical specifications TS 23.237 (current version: 8.2.0) and TS 23.203 (current version: 8.4.0) of the 3GPP.

The following meanings for the abbreviations used in this specification apply: 3GPP: 3rd Generation Partnership Project

AF: Application Function

AVP: Attribute Value Pair iFC: initial Filter Criteria

IMS: IP Multimedia Subsystem IP: Internet Protocol

IP-CAN: IP Continuity Access Network

LTE: Long Term Evolution

PCC: Policy and Charging Control

PCEF: Policy and Charging Enforcement Function PCRF: Policy and Charging Rules Functions

P-CSCF: Proxy Call State Control Function

PMIP: Proxy Mobile IP

QoS: Quality of Service

SAE: System Architecture Evolution SCC AS: Service Centralization and Continuity Application Server S-CSCF: Serving Call State Control Function SIP: Session Initiation Protocol STI: Session Transfer Identifier UE: User Equipment VoIP: Voice over IP

It is one of the design principles of the 3GPP SAE/LTE architecture to establish an anchor to support mobility management, QoS and accounting control which remains in place dur- ing the whole lifecycle of a service, i.e. in particular that the anchor does not change during handover. However, this approach is only applicable if handover between access networks (of differing technology) is supported, e.g. based on network-layer mechanisms, such as Proxy Mobile IP (PMIP) . If this concept is not applicable, higher-layer mechanisms like SIP-based mobility can be employed to enable handover between access networks.

For example, with the specification TS 23.237 (IP Multimedia Subsystem (IMS) Service Continuity) the 3GPP defined the architecture and the basic procedures for an IMS based mobility solution which provides service continuity, i.e. the seamless provisioning of the IMS session, while the network-layer mobility anchor which is correlated with the UE IP address changes during an inter-system handover. The UE is connecting to a new access network and thus receiving a new UE IP address. This new address information is sent to the IMS (via a new P-CSCF) with an "INVITE" message. A Service Centralization and Continuity Application Server (SCC AS) is used to correlate the new INVITE message with an ongoing IMS session based on a Session Transfer Identifier (STI) which was assigned by the SCC AS during the initial IMS session establishment and which is now provided together with the new UE IP address information in the INVITE message. The SCC AS con- tinues the IMS session with the new UE IP address information and terminates the IMS leg that is no longer required, i.e. the part of the IMS signaling path between the SCC AS and the UE via the old P-CSCF.

An access network is often using a policy control functional- ity to be able to manage the resources in an efficient and adequate way for the provisioning of the services. At the same time, the resource usage of each subscriber can be controlled and thus it is ensured that resources are only allocated if there is a corresponding service running and an ap- propriate charging in place. The policy control functionality typically consists of a Policy Decision Point that maintains the operator policies and makes the decisions about the authorization of resources for a service and a Policy Enforcement Point that enforces these decisions by managing the bearer resources and influencing the service traffic of the user accordingly.

The 3GPP SAE/LTE architecture is based on a mobility anchor that contains the Policy Enforcement Point and thus there is only a single Policy Decision Point required. However, in general each access network has its own Policy Enforcement Point and Policy Decision Point and thus it cannot be assumed that a common Policy Decision Point is used, since the access networks may be deployed in a completely independent manner and even belong to different access network operators. Consequently, it may be assumed that there is at least one Policy Decision Point per access network.

The Policy and Charging Rules Function (PCRF) as defined in the specification TS 23.203 is used here as an example for a Policy Decision Point.

Accordingly, after connecting to a new access network and thus receiving a new UE IP address, the UE is sending this new address information to the IMS (via a new P-CSCF) with an INVITE message. For the P-CSCF this is similar to a new IMS session establishment. Consequently, it establishes a new Rx session towards the responsible PCRF (as described in 3GPP TS 23.203) . During this interaction the PCRF receives the information about the IMS session (address and port number infor- mation, media and bandwidth) and the required resources can be authorized for the access.

However, before the resources are authorized the PCRF performs a check against policies which are typically configured by the operator of the access network. For example, an operator may have a policy that is depending on the time of day and thus reject the usage of a high bit rate codec during the rush hours. If the IMS session is not conform to any of the policies, the required resources would not be authorized and the P-CSCF would be informed.

Furthermore, even after the resources have been authorized successfully, the access network still needs to check the availability of the required resources. This is typically done in an aggregated way by using e.g. a bearer concept that treats service traffic with similar QoS demands together. That means the resource request for the IMS session to be transferred could occur together with resource requests of any other services that are started at a similar time. For example, the UE may automatically start an IP TV service once it connects to a certain access network. There is always a chance that the required resources cannot be (fully) allocated. In this case the PCEF informs the PCRF about the services for which resources were insufficient. The PCRF could then retry with a reduced QoS request (e.g. by authorizing service individually) or just decide to inform the respective application function (e.g. the P-CSCF) about it.

Summary of the Invention It is an object of the present invention to enhance service continuity.

According to a first aspect of the present invention, this is accomplished by an apparatus, comprising a controller configured to control a communication session signaling; a detector configured to detect that the communication session signaling relates to an ongoing service; and a processor configured to create an indication signaling including information about the ongoing service.

Modifications of the first aspect may be as follows.

The apparatus according to the first aspect may be configured to be suitable for enhancing service continuity.

The communication session signaling may be at least one of a wireless communication session signaling and a fixed communication session signaling.

The detector may be further configured to analyze the communication session signaling and detect at least one of a session transfer identifier and a replaces header in a session initiation protocol signaling.

The controller may be further configured to provide a proxy call state control functionality.

The processor may be further configured to create the indica- tion signaling including information about the ongoing service as an authorization session establishment signaling.

The communication session signaling may be an internet protocol multimedia subsystem session signaling. The processor may be further configured to generate the information about the ongoing service by using an attribute value pair.

The processor may be further configured to add the information about the ongoing service to one of a dedicated attribute value pair and a value of a service-info-status attribute value pair.

According to a second aspect of the present invention, the object is accomplished by an apparatus, comprising means for controlling a communication session signaling; means for detecting that the communication session signaling relates to an ongoing service; and means for creating an indication sig- naling including information about the ongoing service.

Modifications of the second aspect may correspond to what is set forth above as possible modifications for the apparatus according to the first aspect.

According to a third aspect of the present invention, the object is accomplished by an apparatus, comprising a policy checking element configured to check a request for communication resources for information about an ongoing service; and a decision element configured to prefer authorization of communication resources for an ongoing service over authorization of communication resources for a new service.

Modifications of the third aspect may be as follows.

The apparatus according to the third aspect may be configured to be suitable for enhancing service continuity.

The decision element may be further configured to prefer the authorization of communication resources for the ongoing service by authorizing the communication resources of the ongo- ing service despite non-compliance with operator configured policies .

The decision element may be configured to prefer the authori- zation of communication resources for the ongoing service by authorizing the communication resources of the ongoing service and rejecting the request for communication resources of the new service.

The policy checking element may be further configured to provide a policy and charging rules functionality.

The decision element may be further configured to retrieve the information that the request for communication resources is related to an ongoing service from an authorization session establishment signaling.

The decision element may be further configured to assign a priority in the authorization of communication resources to the ongoing service for its duration, which overrules policies related to a provision of quality of service.

The policy checking element may be further configured to check the request for communication resources for information about an ongoing service by checking for an attribute value pair .

The information about the ongoing service may be one of a dedicated attribute value pair and a value of a service-info- status attribute value pair.

According to a fourth aspect of the present invention, the object is accomplished by an apparatus, comprising means for checking a request for communication resources for informa- tion about an ongoing service; and means for preferring authorization of communication resources for an ongoing service over authorization of communication resources for a new service .

Modifications of the fourth aspect may correspond to what is set forth above as possible modifications for the apparatus according to the third aspect.

According to a fifth aspect of the present invention, the object is accomplished by a method, comprising controlling a communication session signaling by a controller; detecting that the communication session signaling relates to an ongoing service by a detector; and creating an indication signaling including information about the ongoing service by a processor .

Modifications of the fifth aspect may be as follows.

The method according to the fifth aspect may be performed such that it is capable of enhancing service continuity.

The detecting may further comprise analyzing the communication session signaling and detecting at least one of a session transfer identifier and a replaces header in a session initiation protocol signaling.

The method may further comprise providing a proxy call state control functionality by the controller.

The method may further comprise creating the indication signaling including information about the ongoing service as an authorization session establishment signaling by the processor . The communication session signaling may be an internet protocol multimedia subsystem session signaling.

The method may further comprise generating the information about the ongoing service by using an attribute value pair by the processor.

The generating the information about the ongoing service by using an attribute value pair by the processor may include adding the information about the ongoing service to one of a dedicated attribute value pair and a value of a service-info- status attribute value pair.

According to a sixth aspect of the present invention, the object is accomplished by a method, comprising checking a request for communication resources for information about an ongoing service by a policy checking element; and preferring authorizing of communication resources for an ongoing service over authorization of communication resources for a new service by a decision element.

Modifications of the sixth aspect may be as follows.

The method according to the sixth aspect may be performed such that it is capable of enhancing service continuity.

The preferring authorizing of communication resources for the ongoing service may further comprise authorizing the communi- cation resources of the ongoing service despite non-compliance with operator configured policies.

The preferring authorizing of communication resources for the ongoing service may further comprise authorizing the communi- cation resources of the ongoing session and rejecting a request for communication resources of a new service. The method may further comprise providing a policy and charging rules functionality by the policy checking element.

The method may further comprise retrieving the information that the request for communication resources is related to an ongoing service from an authorization session establishment signaling by the decision element.

The method may further comprise assigning a priority in the authorization of communication resources to the ongoing service for its duration by the decision element, which overrules policies related to a provision of quality of service.

The checking a request for communication resources for information about an ongoing service by a policy checking element may be performed by checking for an attribute value pair.

According to a seventh aspect of the present invention, the object is accomplished by a computer program product embodied on a computer-readable medium encoded with instructions that, when executed on a computer, perform: controlling a communication session signaling by a controller; detecting that the communication session signaling relates to an ongoing service by a detector; and creating an indication signaling including information about the ongoing service by a processor.

Modifications of the seventh aspect may correspond to what is set forth above as possible modifications for the method according to the fifth aspect. According to an eighth aspect of the present invention, the object is accomplished by a computer program product embodied on a computer-readable medium encoded with instructions that, when executed on a computer, perform: checking a request for communication resources for information about an ongoing service by a policy checking element; and preferring authorizing of communication resources for an ongoing service over authorization of communication resources for a new service by a decision element.

Modifications of the eighth aspect may correspond to what is set forth above as possible modifications for the method according to the sixth aspect.

According to a ninth aspect of the present invention, the object is accomplished by a system, comprising a proxy call state control function in operable connection with a policy and charging rules function, wherein the proxy call state control function is configured to control a communication session signaling, to detect that the communication session signaling relates to an ongoing service, and to indicate the ongoing service to the policy and charging rules function, and wherein the policy and charging rules function is configured to check a request for communication resources for in- formation about an ongoing service, and to prefer authorization of communication resources for an ongoing service over authorization of communication resources for a new service. The system according to the ninth aspect may be configured to be suitable for enhancing service continuity.

According to a tenth aspect of the present invention, the object is accomplished by a system, comprising controlling means in operable connection with policy means, wherein the controlling means is for controlling a communication session signaling, for detecting that the communication session signaling relates to an ongoing service, and for indicating the ongoing service to the policy means, and the policy means is for checking a request for communication resources for information about an ongoing service, and for preferring authorization of communication resources for an ongoing service over authorization of communication resources for a new service.

The system according to the tenth aspect may be configured to be suitable for enhancing service continuity.

According to an eleventh aspect of the present invention, the object is accomplished by a method, comprising controlling a communication session signaling by a proxy call state control function, detecting that the communication session signaling relates to an ongoing service by the proxy call state control function, indicating the ongoing service to a policy and charging rules function by the proxy call state control function by using an operable connection between the proxy call state control function and the policy and charging rules function, checking a request for communication resources for information about an ongoing service by the policy and charging rules function, and preferring authorization of communication resources for an ongoing service over authorization of communication resources for a new service by the policy and charging rules function.

The method according to the eleventh aspect may be performed such that it is capable of enhancing service continuity.

Brief Description of the Drawings

These and other objects, features, details and advantages will become more fully apparent from the following detailed description of the preferred embodiments which is to be taken in conjunction with the appended drawings, in which: Fig. 1 shows the architecture for service continuity based on IMS service continuity as defined by the 3GPP;

Fig. 2 shows a signaling flow illustrating the forwarding of an indication to the PCRF based on the IMS service continuity as defined by the 3GPP according to certain embodiments of the present invention; and

Fig. 3 shows implementation embodiments of the present inven- tion.

Detailed Description of the preferred Embodiments

In the following, description will be made to what are pres- ently considered to be preferred embodiments of the present invention. It is to be understood, however, that the description is given by way of example only, and that the described embodiments are by no means to be understood as limiting the present invention thereto.

For example, for illustration purposes, in some of the following exemplary embodiments, service continuity between a 3GPP access network and a non-3GPP access network is described. However, it should be appreciated that these exem- plary embodiments are not limited for use among these particular types of wireless communication systems, and according to further exemplary embodiments, the present invention can be applied also to the service continuity between Circuit Switched (CS) and Packet Switched (PS) access networks or other types of fixed or wireless communication systems and access networks such as e.g. to WLAN (wireless local area network) and WIMAX (worldwide interoperability for microwave access) techniques and standards.

Furthermore, certain embodiments of the present invention are described herein below with respect to IMS services. However, the present invention is not restricted thereto and other embodiments of the present invention are related to messenger services or VoIP services. For example, as an instance of the IMS, i.e. a core network subsystem, in the following descrip- tion is made with respect to the exemplary example of a

P-CSCF. However, this is not intended to limit the invention in any way. For example, certain embodiments of the present invention are related to any instance of an application function (AF), i.e. an element offering applications that require dynamic policy and/or charging control over IP-CAN user plane behaviour. An AF may be typically enabled to communicate with a PCRF to transfer dynamic session information, required for PCRF decisions as well as to receive IP-CAN specific information and notifications about IP-CAN bearer level events.

Under these premises, certain embodiments of the present invention include the following.

In the situations described above in the introductory part (i.e. non-conformance with access network operator policies or insufficient resources while other services are started in parallel) the PCRF is not able to know that the IMS session is subject to IMS service continuity and thus cannot perform a preferred treatment, i.e. to try to keep the IMS session alive.

Consequently, the PCRF can only inform the P-CSCF about the failure of resource authorization which would lead to a failure of the IMS service continuity procedure. In the extreme case, the IMS session would have to be terminated if the connectivity via the initial access network is no longer possible.

Furthermore, operators are required to carefully negotiate the operator policies for the access networks to ensure that a non-conformance to policies is a rare event. The following exemplary embodiments of the present invention provide service continuity by overcoming the limitations mentioned above with respect to the prior art in that the P-CSCF detects that the INVITE belongs to an ongoing IMS session and informs the PCRF about the fact that the Rx session does belong to an ongoing service (compared to a new service that is still in the establishment phase) . The detection can be based on the identification of the Session Transfer Identifier (STI) in the IMS session signaling or the identification of the REPLACES header.

The PCRF can use this indication to allow a violation of the access network operator policies for the ongoing service.

For example, a policy that limits the bandwidth for a certain QoS class to 100kbit/s would not lead to an authorization rejection if the IMS session is currently using 150kbit/s for the respective media flow. Any new services however, would still be subject to this policy.

Furthermore, the PCRF can then differentiate this service (e.g. the IMS session) from any other service that is started in parallel in case of insufficient resources. The ongoing service can be prioritized and its required resources can be checked/re-checked individually and before the resources of the other services (to be started) .

The indication that the RX session belongs to an ongoing ser- vice may be added to the Rx signaling as a separate AVP (like the SIP-Forking-Indication AVP), i.e. the AVP is newly created and dedicated for this special purpose, or as a new value to the Service-Info-Status-AVP . The P-CSCF sends the indication when the Rx session is established, i.e. in the AA-Request (AAR) command. The PCRF stores this indication and applies it for the policy conformance check and the resource authorization phase.

This indication enables a specific treatment of an Rx session that belongs to an ongoing service (compared to a new service that is still in the establishment phase) . Since the violation of access network operator policies becomes possible, the need for inter-operator negotiation of access network policies decreases. Furthermore, ongoing services can be pri- oritized over services that are just starting.

In the end, the chance for a successful service continuity procedure increases as the risks for policy control related failures are minimized.

On a more general level, but still related only to certain embodiments not limiting the present invention, an AF may thus provide a priority indicator and/or an AF ongoing service indicator to enable the PCRF to resolve conflicts where the activation of all requested active PCC rules for services would result in a cumulative authorized QoS which exceeds the subscribed guaranteed bandwidth QoS or the resources that are currently available.

The priority indicator may be used by the PCRF to prioritize a new AF session with a higher relative priority against a new AF session with a lower relative priority. The ongoing service indicator may be used by the PCRF to prioritize an ongoing AF session against a new AF session. That is, if the AF provides the ongoing service indicator, the PCRF may apply this indicator in a check against operator defined policies to enable a less restrictive treatment of ongoing AF sessions. In addition, a service pre-emption priority may be used by the PCRF to prioritize a new or ongoing AF session against another ongoing AF session. Thus, if an AF detects from AF session signalling that an AF session is already established (which e.g. happens in case of an AF session transfer) , the AF may send the ongoing service indicator to the PCRF to enable a prioritization of the ongo- ing AF session and to reduce the risk of failure in the check against operator defined policies.

Certain embodiments of the present invention are described in further detail below by referring to the accompanying draw- ings.

Fig. 1 illustrates by way of example an architecture for service continuity based on 3GPP IMS service continuity.

Specifically, Fig. 1 shows the situation of an intersystem handover, i.e. where access of a UE 11 to a 3GPP IMS network 10 is handed over from a 3GPP access network 121 to a non-3GPP access network 122, i.e. without network layer mobility support, for example. Even though, both access net- works comprise a PCRF 171, 172 and PCEF 181, 182, respectively, which are connected over a Gx interface. In turn, both access networks enable connectivity to the 3GPP IMS network 10 by a connection of the PCEF 181, 182 to the SCC AS 14 of the 3GPP IMS network 10, and a connection of the PCRF 171, 172 to a P-CSCF 15, 16 of the 3GPP IMS network 10, respectively, which P-CSCF 15, 16 in turn are connected to the SCC AS 14. In most of the cases (as shown in Fig. 1), the P-CSCF 16 after the handover is a new one.

Thus, according to certain embodiments of the present invention, the combination of a "new" PCRF 182 and a "new" P-CSCF 16 may form a system, comprising a proxy call state control function 16 in operable connection with a policy and charging rules function 172, wherein the proxy call state control function 16 is configured to control a communication session signaling, to detect that the communication session signaling relates to an ongoing service (for example by detecting a session transfer identifier transmitted by the UE 11'), and to indicate the ongoing service to the policy and charging rules function 172, and wherein the policy and charging rules function 172 is configured to check a request for communication resources for information about an ongoing service and to prefer authorization of communication resources for an ongoing service over authorization of communication resources for a new service.

The old (121) and new (122) access networks could be of any known type (for example fixed and wireless access network types or circuit switched and packet switched access network types or IP-CANs) or of any possible combination of known types.

Fig. 2 illustrates by way of example a signaling flow showing the forwarding of a new indication to a PCRF 272 based on 3GPP service continuity. Fig. 2 is based on Figure 6.3.2.2.1- 1 of TS 23.237 (version 8.2.0) .

Thus, Fig. 2 specifically shows in a first step that, for a media path connection to a UE-2 212, UE-I 211 connects to a new access network (for example a non-3GPP access network as shown in Fig. 1) and receives (a) new IP address (es) . In a second step, UE-I 211 registers to a S-CSCF 29 (located between P-CSCF and SCC AS, not shown in Fig. 1) via the new access network. This registration may go through the same (old=new) P-CSCF or a different (new) P-CSCF 26. According to a third step, the UE-I 211 sends an INVITE message on the new access network towards the SCC AS 24 to the new P-CSCF 26. The INVITE message includes a session transfer identifier (STI) identifying the session to be transferred. The INVITE message also indicates to the SCC AS 24 that it performs ac- cess transfer with full media transfer. In a fourth step, the P-CSCF 26 detects the STI in the signaling and thus detects that the signaling relates to an ongoing service (ongoing session) (the detection can be also done other ways; using STI is just one example) . This information about the ongoing service is indicated in a fifth step by signaling to the new PCRF 272, e.g. by Rx session establishment signaling. The new PCRF 272 checks (step 6a) the request for communication resources for the information about an ongoing service and in response thereto prefers this ongoing service over new service requests, which might happen even if operator polices have to be violated for authorizing corresponding communication resources (step 6b) . The violation of operator policies might be even allowed if there is no new service request where the ongoing service can be preferred over. Then, the Rx session establishment signaling is acknowledged by the PCRF 272 to the P-CSCF 26 in a seventh step, whereupon the P-CSCF 26 send the INVITE (STI) to the S-CSCF 29 (step 8) . In a ninth step, the S-CSCF 29 establishes service logic with initial filter criteria, and in a tenth step, the S-CSCF 29 sends the INVITE (STI) to the SCC AS 24. In an eleventh step, the SCC AS 24 identifies the session based on STI and updates the session over the remote access leg. In a twelfth step, the SCC AS 24 completes the session setup with UE-I 211 on the new access leg and releases the old access leg based on the standard IMS procedures.

As is illustrated in Fig. 2, according to certain embodiments of the present invention there are new steps where the P-CSCF 26 controlling the communication session signaling by a controller detects by a detector that the communication session signaling relates to an ongoing service, for example by the session transfer identifier in the communication session signaling. Thus, the P-CSCF 26 is enabled to create an indication signaling including information about the ongoing service by a processor. This signaling may be the Rx session es- tablishment signaling towards the PCRF 272, as indicated in Fig. 2, step 5. The PCRF 272 is enabled to check a request for communication resources for information about an ongoing service, and to prefer authorizing (step 6b/step 7: ACK) of communication resources for an ongoing service over authorization of communication resources for a new service.

However, according to certain embodiments of the present invention, the PCRF 272 is also enabled to authorize communication resources despite non-compliance with the policies related to, for example, the provision of quality of service by a decision element if information is present that a request for communication resources is related to an ongoing service. Apparently, such information may be present due to the indication signaling of the P-CSCF 26 from which the information can be retrieved. In response, a corresponding Rx session es- tablishment acknowledgment may be sent (step 7) .

As options, there can be assigned a priority in the authorization of communication resources, wherein such assignment can be permanent or only for a limited time. The assignment may be done by the new P-CSCF or the PCRF.

Furthermore, as illustrated by Fig. 3, certain embodiments of the present invention relate to an apparatus 36, comprising a controller 361 configured to control a communication session signaling, a detector 362 configured to detect that the communication session signaling relates to an ongoing service, and a processor 363 configured to create an indication signaling including information about the ongoing service.

According to certain embodiments of the present invention, the apparatus 36 can be implemented as a P-CSCF or a component thereof. This first apparatus 36 may be provided separately or on operable connection with a second apparatus 372.

Further, certain embodiments of the present invention relate to an apparatus 372, comprising a policy checking element 3721 configured to check a request for communication resources for information about an ongoing service, and a decision element 3722 configured to prefer authorization of communication resources for an ongoing service over authoriza- tion of communication resources for a new service.

According to further embodiments of the present invention modified from these, the decision element 3722 is further configured to prefer the authorization of communication re- sources for the ongoing service by authorizing the communication resources of the ongoing service despite non-compliance with operator configured policies. Alternatively or in addition, a request for communication resources of a new service can be rejected.

The apparatus 372 can be implemented as a policy and charging rules functionality, for example by configured the policy checking element 3721 to provide a policy and charging rules functionality.

Further embodiments of the present invention are related to that the decision element 3722 is further configured to retrieve the information that the request for communication resources is related to an ongoing service from an authoriza- tion session establishment signaling, and, alternatively or in addition, that the decision element 3722 is further configured to assign a priority in the authorization of communication resources to the ongoing service for its duration, which overrules policies related to a provision of quality of service.

According to the above description, it should thus be apparent that exemplary embodiments of the present invention provide, for example from the perspective of a network element such as a Proxy Call State Control Function (P-CSCF) and a

Policy and Charging Rules Functions (PCRF), respectively, or a component thereof, an apparatus embodying the same, a method for controlling and/or operating the same, and computer program (s) controlling and/or operating the same as well as mediums carrying such computer program (s) and forming computer program product (s) .

For example, described above are apparatuses, methods and computer program products capable of providing policy control enhancement for service continuity.

Implementations of any of the above described blocks, apparatuses, systems, techniques or methods include, as non limiting examples, implementations as hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

What is described above is what is presently considered to be preferred embodiments of the present invention. However, as is apparent to the skilled reader, these are provided for illustrative purposes only and are in no way intended that the present invention is restricted thereto. Rather, it is the intention that all variations and modifications be included which fall within the spirit and scope of the appended claims.

Claims

Claims :

1. An apparatus, comprising: a controller (361) configured to control a communication session signaling; a detector (362) configured to detect (4) that the communication session signaling relates to an ongoing service; and a processor (363) configured to create an indication signaling (5) including information about the ongoing service .

2. The apparatus according to claim 1, wherein the communication session signaling (5) is at least one of a wireless com- munication session signaling and a fixed communication session signaling.

3. The apparatus according to claim 1 or 2, wherein the detector (362) is further configured to analyze the communica- tion session signaling and detect at least one of a session transfer identifier and a replaces header in a session initiation protocol signaling.

4. The apparatus according to any one of claims 1 to 3, wherein the controller (361) is further configured to provide a proxy call state control functionality (16; 26; 36) .

5. The apparatus according to any one of claims 1 to 4, wherein the processor (363) is further configured to create the indication signaling (5) including information about the ongoing service as an authorization session establishment signaling.

6. The apparatus according to any one of claims 1 to 5, wherein the communication session signaling is an internet protocol multimedia subsystem session signaling.

7. The apparatus according to any one of claims 1 to 6, wherein the processor (363) is further configured to generate the information about the ongoing service by using an attrib- ute value pair.

8. The apparatus according to claim 7, wherein the processor (363) is further configured to add the information about the ongoing service to one of a dedicated attribute value pair and a value of a service-info-status attribute value pair.

9. An apparatus, comprising: a policy checking element (3721) configured to check (6a) a request for communication resources for information about an ongoing service; and a decision element (3722) configured to prefer (6b) authorization of communication resources for an ongoing service over authorization of communication resources for a new service .

10. The apparatus according to claim 9, wherein the decision element (3722) is further configured to prefer (6b) the authorization of communication resources for the ongoing service by authorizing the communication resources of the ongo- ing service despite non-compliance with operator configured policies .

11. The apparatus according to claim 9, wherein the decision element (3722) is configured to prefer the authorization of communication resources for the ongoing service by authorizing the communication resources of the ongoing service and rejecting a request for communication resources of a new service .

12. The apparatus according to any one of claims 9 to 11, wherein the policy checking element (3721) is further configured to provide a policy and charging rules functionality (172; 272; 372) .

13. The apparatus according to any one of claims 9 to 12, wherein the decision element (3722) is further configured to retrieve the information that the request for communication resources is related to an ongoing service from an authorization session establishment signaling.

14. The apparatus according to any one of claims 9 to 13, wherein the decision element (3722) is further configured to assign a priority in the authorization of communication resources to the ongoing service for its duration, which overrules policies related to a provision of quality of service.

15. The apparatus according to any one of claims 9 to 14, wherein the policy checking element (3721) is further configured to check (6a) the request for communication resources for information about an ongoing service by checking for an attribute value pair.

16. The apparatus according to claim 15, wherein the information about the ongoing service is one of a dedicated attribute value pair and a value of a service-info-status attribute value pair.

17. A method, comprising: controlling a communication session signaling by a controller (361); detecting (4) that the communication session signaling relates to an ongoing service by a detector (362); and creating an indication signaling (5) including information about the ongoing service by a processor (363) .

18. The method according to claim 17, wherein the communication session signaling is at least one of a wireless communi- cation session signaling and a fixed communication session signaling .

19. The method according to claim 17 or 18, wherein the detecting (4) further comprises analyzing the communication session signaling and detecting at least one of a session transfer identifier and a replaces header in a session ini- tiation protocol signaling.

20. The method according to any one of claims 17 to 19, further comprising providing a proxy call state control functionality (16; 26; 36) by the controller (361) .

21. The method according to any one of claims 17 to 20, further comprising creating (5) the indication signaling including information about the ongoing service as an authorization session establishment signaling by the processor (363) .

22. The method according to any one of claims 17 to 21, wherein the communication session signaling is an internet protocol multimedia subsystem session signaling.

23. The method according to any one of claims 17 to 22, further comprising generating the information about the ongoing service by using an attribute value pair by the processor (363) .

24. The method according to claim 23, wherein the generating the information about the ongoing service by using an attribute value pair by the processor (363) includes adding the information about the ongoing service to one of a dedicated attribute value pair and a value of a service-info-status at- tribute value pair.

25. A method, comprising: checking (6a) a request for communication resources for information about an ongoing service by a policy checking element (3721); and preferring (6b) authorizing of communication resources for an ongoing service over authorization of communication resources for a new service by a decision element (3722) .

26. The method according to claim 25, wherein the preferring (6b) authorizing of communication resources for the ongoing service further comprises authorizing the communication re- sources of the ongoing service despite non-compliance with operator configured policies.

27. The method according to claim 25, wherein the preferring (6b) authorizing of communication resources for the ongoing service further comprises authorizing the communication resources of the ongoing session and rejecting a request for communication resources of a new service.

28. The method according to any one of claims 25 to 27, fur- ther comprising providing a policy and charging rules functionality (172; 272; 372) by the policy checking element (3721) .

29. The method according to any one of claims 25 to 28, fur- ther comprising retrieving the information that the request for communication resources is related to an ongoing service from an authorization session establishment signaling (5) by the decision element (3722) .

30. The method according to any one of claims 25 to 29, further comprising assigning a priority in the authorization of communication resources to the ongoing service for its duration by the decision element (3722), which overrules policies related to a provision of quality of service.

31. The method according to any one of claims 25 to 30, wherein the checking (6a) a request for communication resources for information about an ongoing service by a policy checking element (3721) is performed by checking for an at- tribute value pair.

32. The method according to claim 31, wherein the information about the ongoing service is one of a dedicated attribute value pair and a value of a service-info-status attribute value pair.

33. A computer program product embodied on a com- puter-readable medium encoded with instructions that, when executed on a computer, perform: controlling a communication session signaling by a controller (361); detecting (4) that the communication session signaling relates to an ongoing service by a detector (362); and creating an indication signaling (5) including information about the ongoing service by a processor (363) .

34. A computer program product embodied on a com- puter-readable medium encoded with instructions that, when executed on a computer, perform: checking (6a) a request for communication resources for information about an ongoing service by a policy checking element (3721); and preferring (6b) authorizing of communication resources for an ongoing service over authorization of communication resources for a new service by a decision element (3722) .

35. A system, comprising: a proxy call state control function (16; 26; 36) in operable connection with a policy and charging rules function (172; 272; 372), wherein the proxy call state control function (16; 26; 36) is configured to control a communication session signal- ing, to detect (4) that the communication session signaling relates to an ongoing service, and to indicate (5) the ongoing service to the policy and charging rules function (172; 272; 372), and wherein the policy and charging rules function (172; 272; 372) is configured to check (6a) a request for communication resources for information about an ongoing service, and to prefer (6b) authorization of communication resources for an ongoing service over authorization of communication resources for a new service.