Patent Description:
Some embodiments of the present invention relate to usage monitoring. Usage monitoring can be applied to an accumulated usage of network resources on a per IP-CAN session and user basis. This capability is required for enforcing dynamic policy decisions based on the total network usage in real-time.

A PCRF that uses usage monitoring for making dynamic policy decisions sets and sends applicable thresholds to a PCEF or TDF for monitoring. The usage monitoring thresholds may be based e.g. on volume or actively used time. The PCEF or TDF notifies the PCRF when a threshold is reached and reports the accumulated usage since the last report for usage monitoring.

The usage monitoring capability can be applied to an individual service data flow, a group of services data flows, or to all traffic of an IP-CAN session in the PCEF. Usage monitoring, if activated, is performed both for service data flows associated with predefined PCC rules and dynamic PCC rules, including rules with deferred activation and/or deactivation times while those rules are active.

A usage monitoring group, when only a single user / UE is connected, is a set of service data flow(s)/application(s) of a user / UE that share a common traffic usage allowance and need to be monitored together for usage monitoring control purposes. Within a wider concept addressed in this application, a usage monitoring group comprises service data flows/applications of several users / UEs that share a common traffic usage allowance and need to be monitored together for usage monitoring control purposes.

The present application is not only directed to usage monitoring groups, but also other kinds of policy controlled groups. For example, 3GPP SA21 has a Rel-<NUM> work item on Group Communication System Enablers for LTE (GCSEL), refer to the draft 3GPP TS <NUM>. The scope of the Wl reads as follows:
The present document collects the requirements as relevant to improve the EPC and E-UTRAN for system enablers to the 3GPP system to support group communication over LTE for Public Safety. The application layer making use of the group communication service enablers specified below is out of scope of this work. The US requirements as specified in NPSTC (Mission Critical Voice Requirements) are taken as starting point. Other regional requirements may also be reflected in the work. The requirements shall be worded in a way to easily accommodate future requirements from other regions or stakeholders.

Among other things, the following requirements should be fulfilled (e.g., 3GPP document S1-<NUM>):.

3GPP SA2 has also a Rel-<NUM> study on Usage Monitoring Control PCC Enhancements, refer to the prior art draft TR <NUM>. One of the key issues of this study is Usage Monitoring for Subscriber Group.

Handling of subscriber groups may involve problems, as will be described in the following.

Mobile networks typically apply the "always-on" principle, i.e. when a UE is switched on, it attaches a mobile network and establishes a default context / bearer with the network. And if policy and charging control (PCC) is deployed in the network, the network allocates a policy and charging control function (PCRF) for the UE and its network context. This relationship is maintained as long as the UE is connected to the network.

A major problem with this is that if the user/UE is included/added in a policy and/or charging controlled group while already being attached to the network, the UE and the rest of the group members may be served by different PCRFs, selected upon IP-CAN session establishment. Handling of common / group related policy and/or charging control activities, e.g. monitoring of the usage of common quota, would be impossible or very complicated with several PCRFs involved in the process.

The problem is acute within the Group Communication System Enablers for LTE (GCSEL) work item even without an "always-on" principle, because it quite obviously does not make sense that possible to-be-joined-into-a-public-safety-group subscribers were not online / connected and because the joined-in subscribers shall be notified of being added to the group.

Prior art document <CIT> describes a resource handling and controlling method applying policy control rules applicable to group session to all Internet protocol connectivity access network sessions associated with group session; Prior art document <CIT> discloses a congestion control method comprising a group load indicator and adjusting session parameters according to group load condition of the group.

The invention is carried out as described in the appended claims.

Embodiments of the present invention address this situation and aim to overcome the above-described problems and to provide a reliable management of policy controlled groups.

According to claim <NUM>, a PCRF is provided.

According to claim <NUM> an apparatus is provided.

According to claim <NUM> an inter-related apparatus is provided.

According to claim <NUM> a method is provided.

According to claim <NUM>, an inter-related method is provided.

According to claim <NUM> an inter-related method is provided.

Modifications of the above aspects are defined in the dependent claims.

According to claim <NUM> a computer program product is provided.

The computer program product may be embodied on a computer-readable medium, for example.

Thus, according to embodiments of the present invention, handling/serving of a user equipment wishing to join a policy controlled group which is not handled by a certain rules function can be transferred to a rules function which also controls the policy controlled group. Thus, since the policy controlled group and the user equipment can be handled/served by the same rules function, a reliable management of policy controlled groups can be achieved.

These and other objects, features, details and advantages will become more fully apparent from the following detailed description of embodiments of the present invention which is to be taken in conjunction with the appended drawings, in which:.

In the following, description will be made to 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.

However, before explaining embodiments of the present invention in detail, a logical architecture of a PCC functionality to which embodiments of the present invention may be applied is described by referring to <FIG>. The PCC functionality is comprised by the functions of a PCEF (policy and charging enforcement function) included in a gateway node, a BBERF (bearer binding and event reporting function), a PCRF (policy and charging rules function), an AF (application function), a TDF (traffic detection function), an OCS (online charging system), an OFCS (offline charging system) and an SPR (subscription profile repository) or UDR (user data repository).

The PCEF is connected to the PCRF, the OCS and the OFCS via Gx, Gy and Gz interfaces, respectively.

The PCRF is connected to the BBERF, the AF, the TDF and the OCS via Gxx, Rx, Sd und Sy interfaces, respectively.

The SPR/UDR is applied to store PCC related subscription data. An Sp/Ud interface between PCRF and SPR/UDR is used to access subscription data in the SPR/UDR. The PCC architecture extends the architecture of an IP-CAN, where the PCEF is a functional entity in a gateway node implementing IP access to a PDN.

As mentioned above, in such a situation problems may occur when a UE served/handled by particular PCRF joins a policy controlled group (e.g., a usage monitoring group) which is served/handled by another PCRF. According to embodiments of the present invention, all UEs belonging to the same policy and charging controlled group, e.g. monitoring group, should preferably use the same PCRF.

In the following, a general embodiment of the present invention is described by referring to <FIG> according to which the above measure can be achieved. It is noted that the elements described in the following may be applied to the architecture described above by referring to <FIG>, but that the elements may also applied in other suitable architectures.

<FIG> shows a PCRF or a network element carrying out the corresponding function, as an example for a corresponding apparatus applying an embodiment of the present invention. The PCRF is only an example, and also other suitable network elements performing a rules function could be applied. For example, the PCRF may be implemented in a gateway node.

The PCRF <NUM> comprises a processor <NUM> and a connection unit <NUM>. The connection unit <NUM> is configured to provide a connection to a communication network. The processor <NUM> is configured to receive a notification informing that a user equipment is to be included in a policy controlled group via the connection unit, to check whether the policy controlled group is controlled by the apparatus, and, in case the policy controlled group is not controlled by the apparatus, to cause a transfer of the policy control session for the user equipment to a rules function (e.g., another PCRF) controlling the policy controlled group.

In case the policy controlled group is controlled by the apparatus, no transfer is necessary and the user equipment will be controlled by the apparatus.

<FIG> shows a PCEF or a corresponding network element carrying out the function thereof, as an example for a corresponding apparatus applying an embodiment of the present invention. The PCEF is only an example, and also other suitable network elements performing an enforcement function could be applied.

The PCEF <NUM> comprises a processor <NUM> and a connection unit <NUM>. The connection unit <NUM> is configured to provide a connection to a communication network. The processor <NUM> is configured to receive a request from a first rules function (e.g., the PCRF <NUM> handling/serving the user equipment) including information that a user equipment is to be included in a policy controlled group which is not controlled by the first rules function, and to cause a determination of a second rules function (e.g., a PCRF handling/serving the group) which controls the policy controlled group.

<FIG> shows a DRA or a corresponding network element carrying out a routing function thereof, as an example for a corresponding apparatus applying an embodiment of the present invention. The DRA is only an example, and also other suitable network elements performing a routing function could be applied.

The DRA <NUM> comprises a processor <NUM> and a connection unit <NUM>. The connection unit <NUM> is configured to provide a connection to a communication network. The processor <NUM> is configured to receive a request from an enforcement function (e.g., the PCEF <NUM>) including information that a user equipment attached to a first rules function is to be included in a policy controlled group which is not controlled by the first rules function, and to determine a second rules function which controls the policy controlled group.

Thus, the above-described elements perform procedures such that when a user equipment handled/served by a certain rules function (such as the PCRF <NUM>) wishes to join a policy controlled group which is not handled by this certain rules function, the rules function determines that rules function handling/serving the group, namely by forwarding a corresponding request to an enforcement function (such as the PCEF <NUM>). The enforcement function in turn causes a determination of the correct rules function (e.g., another PCRF) which handles/serves the group. For example, this can be effected by sending a corresponding request to the routing element (such as the DRA <NUM>), which is able to determine the correct PCRF.

In this way, handling/serving of the user equipment can be transferred to the rules function (PCRF) which also controls the policy controlled group.

Optionally, the PCRF <NUM>, the PCEF <NUM> and the DRA <NUM> may further comprise respectively memories <NUM>, <NUM> and <NUM> for storing data and programs, by means of which the corresponding processors <NUM>, <NUM> and <NUM> may carry out their corresponding functions.

In the following, a more detailed embodiment of the present invention is described. This embodiment is applied to the architecture as described above in connection with <FIG>.

In particular, when a user / UE that is already attached to the network, is included/added in a policy controlled group, e.g. a Group Communication related group or a usage monitoring group, the group management entity, e.g. the subscription register (SPR / UDR) informs the PCRF of the UE about the event by sending a notification to the PCRF. The notification contains relevant group identification information, e.g. a Group ID, and may contain other group or service related information, e.g. policy and/or charging rules, or quotas or thresholds in case of a monitoring group.

The PCRF checks whether it itself handles / serves the group with the identification information sent by the group management entity / SPR/UDR. If not, the PCRF (PCRF-A) initiates a PCRF change procedure for the user / UE. It is to be noted that in the following the PCRF handling/serving the UE initially is referred to as PCRF-A, whereas the PCRF handling/serving the group is referred to as PCRF-Group. The change procedure comprises:
The PCRF-A requesting the PCEF (and BBERF, if applicable) to establish a Gx (and Gxx, if applicable) control session to the PCRF ("PCRF-Group") which currently controls / serves the policy control group matching the group identification (sent by the SPR/UDR).

Terminating the current Gx control session between the PCEF and PCRF-A (and Gxx session between BBERF and PCRF-A, if applicable). The termination of the Gx session between PCRF-A and PCEF (and of the Gxx session between PCRF-A and BBERF, if applicable) may be performed / commanded by the PCRF-A, in which case the termination command may contain the parameters (e.g. Group ID) needed for the establishment of the Gx (/ Gxx) session towards the PCRF-Group, or the PCRF-A just sends a request (with parameters) to the PCEF (/ BBERF) and lets the PCEF (/ BBERF) terminate the Gx (/Gxx) session(s) when appropriate either before or after establishing the corresponding control session(s) to the PCRF-Group.

<FIG> describes the basic solution according to the present embodiment in form of a signalling scenario with the following steps:.

As an alternative to the above, in step S9, after finding the correct PCRF (i.e., the PCRF-Group), the DRA may request the PCEF to redirect the request to the correct PCRF (PCRF-Group). This request may include the information as describe above, e.g., user ID, IP address, group ID, parameters etc., and may in addition contain information regarding the identity and/or address of the PCRF-Group. That is, this request to redirect would replace step S10. The PCEF will then redirect the request.

In the following, some alternative embodiments are described by which it can be achieved to handle possible simultaneous services:
In order to ensure that the control of ongoing services of the user / UE is not disrupted, the following further control actions may take place:
The PCRF-A may delay sending the PCRF change request (S6 in <FIG>) or the control session termination command to the PCEF (S14 in <FIG>) until ongoing service related policy and/or charging control actions or the services themselves have terminated. If in the meantime a service belonging to the group control (e.g. usage monitoring) is started, the PCRF-A performs relevant actions (e.g. monitoring control and report reception) and may include related information / parameters in the request / command sent to the PCEF, which may send the information / parameters further to the PCRF-Group if/when applicable. For example the already reported usage could be information needed by the PCRF-Group.

Alternatively, the PCRF-A may send the request (S6 in <FIG>)/ command (S14 in <FIG>) after having received the related notice / indication from the SPR/UDR, but the PCEF may delay the starting of the related PCRF change actions until ongoing service related policy and/or charging control actions or the services themselves have terminated. If in the meantime a service belonging to the group control (e.g. usage monitoring) is started, the PCEF takes care of reporting relevant information / parameters to the PCRF-Group (after establishing a Gx control session).

If an ongoing service belongs to the category of the group the user / UE is just joining, the behaviour may be e.g. as follows (depending e.g. by configuration):.

For implementing the above-described procedures, advantageously new parameters / AVPs could be introduced to indicate the need for changing the PCRF (and the possible transfer of information (e.g. monitoring results) to the new PCRF. This applies in particular when the procedures of the above-described alternative embodiments are applied.

Embodiments of the present application may be applied in the environment regarding usage monitoring groups as described in 3GPP TR <NUM>.

It is to be noted that the embodiments and the present invention in general are not limited to the specific examples given above, but they are limited by the scope of the claims.

For example, the procedures may also be applied to other policy controlled groups than usage monitoring groups or group communication services (GCSEL).

According to the embodiments described above in connection with <FIG>, a Gx control session is established between the PCEF and the PCRF-Group (and/or a Gxx control session between the BBERF and the PCRF-Group). However, the invention is not limited to a Gx (or Gxx) control session, and any kind of control session can be applied which allows exchange of necessary information, parameters etc. between the network elements involved.

In general, the exemplary embodiments of this invention may be implemented by computer software stored in the memories (memory resources) <NUM>, <NUM>, <NUM> and executable by the processors (processing resources) <NUM>, <NUM>, <NUM>, or by hardware, or by a combination of software and/or firmware and hardware in the corresponding apparatuses.

It is to be understood that any of the above modifications can be applied singly or in combination to the respective aspects and/or embodiments to which they refer, unless they are explicitly stated as excluding alternatives as far as any modification falls within the scope of the appended claims.

For the purpose of the present invention as described herein above, it should be noted that.

Claim 1:
A policy and charging rules function comprising:
receiving means for receiving a notification informing that a user equipment is to be included into a policy controlled group,
checking means for checking whether the policy controlled group is controlled by the policy and charging rules function, and
causing means for causing, in case the policy controlled group is not controlled by the policy and charging rules function, a transfer of a policy control session for the user equipment to a second policy and charging rules function controlling the policy controlled group.