At S50211, a registration request associated with the PDU session of the UE is sent to the BSF network element, so that the BSF network element selects the first PCF network element for the PDU session of the UE when the BSF network element determines that the first PCF network element may serve as the same PCF network element based on the registration request. The registration request includes a UE group identifier of the UE group.

In this embodiment, when the first PCF network element determines there is a need to select for the PDU session of the UE, the same PCF network element serving each UE within the UE group to which the UE belongs, the first PCF network element sends a registration request carrying the UE group identifier of the UE group to the BSF network element, so that the BSF network element may select the same PCF network element for the PDU session of the UE based on the UE group identifier. That is, the BSF network element selects the same PCF network element for a PDU session of each UE in the UE group, based on the UE group identifier of a group of UEs.

In some embodiments, the UE group identifier may be obtained by querying the user description of the UE stored in the UDR.

The user description of the UE stored in the UDR may record a UE group identifier of a UE group to which a UE belongs, so that any network device in need may obtain a UE group identifier of a UE group to which a UE belongs by querying a user description of the UE stored in the UDR. For example, when the PCF network element determines that there is a need to select the same PCF network element serving each UE in the UE group to which the UE belongs for the PDU session of the UE, the PCF network element may obtain the UE group identifier of the UE group by querying the user description of the UE stored in the UDR, enable the UE group identifier to be carried in the registration request and send to the BSF network element, so as to request to select the same PCF network element for the PDU session of the UE.

Usually, after the BSF network element receives a registration request for a certain PDU session from a certain PCF network element, the BSF network element may give priority to selecting the PCF network element for the PDU session. However, in this embodiment, after the BSF network element receives a registration request for a PDU session of a certain UE that carries a UE group identifier from the first PCF network element, even if the registration request comes from the first PCF network element, the BSF network element will determine whether the first PCF network element may serve as the same PCF network element since the registration request carries a UE group identifier (which indicates it is expected to select for the PDU session of the UE, the same PCF network element serving each UE in the UE group to which the UE belongs). Only when the first PCF network element may serve as the same PCF network element, the BSF network element may select the first PCF network element for the PDU session of the UE.

In some embodiments, a condition for the first PCF network element that may serve as the same PCF network element includes one of: binding information including the UE group identifier is not registered in the BSF network element; or binding information including the UE group identifier is registered in the BSF network element and a PCF network element indicated in the registered binding information is the first PCF network element.

The BSF network element may determine whether the first PCF network element may serve as the same PCF network element according to a registration state of the binding information.

For example, if the binding information including the UE group identifier is not registered in the BSF network element, meaning that the BSF network element has not selected a PCF network element for a PDU session of any UE in the UE group. In this case, any PCF network element may be selected for the PDU session of the UE. Considering that the registration request is sent by the first PCF network element, the first PCF network element may serve as the same PCF network element and the first PCF network element is selected for the PDU session of the UE.

For another example, if the binding information including the UE group identifier is registered in the BSF network element, meaning that the BSF network element has selected a PCF network element for a PDU session of a UE within the UE group, it may be determined based on the registered binding information whether a PCF network element that has been selected for the PDU session of the UE within the UE group (hereinafter may be referred to as the “selected PCF network element”) is the first PCF network element. Usually, the binding information may record information on the selected PCF network element. If the information on the selected PCF network element indicates that the selected PCF network element is the first PCF network element, meaning that the same PCF network element serving each UE within the UE group is the first PCF network element, the first PCF network element may be selected for the PDU session of the UE.

By implementing this embodiment, when the PCF network element determines that there is a need to select for the PDU session of the UE, the same PCF network element serving each UE in the UE group to which the UE belongs, the PCF network element sends a registration request carrying the UE group identifier of the UE group to the BSF network element, and selects the same PCF network element for the PDU session of the UE, so as to achieve the purpose of selecting the same PCF network element for each UE within the same UE group.

FIG. 6 illustrates a flowchart of a method for selecting a PCF network element according to an embodiment of the present disclosure. The method is applied to the first PCF network element. Based on the embodiment described in FIG. 5, as shown in FIG. 6, the method may include but is not limited to the following steps.

At S601, when the received policy association establishment request is related to the PDU session of the UE within the UE group, it is determined whether to select the same PCF network element serving each UE in the UE group for the PDU session of the UE.

Regarding the specific implementation details of the step S601, reference may be made to the related descriptions of the step S101 in the embodiment shown in FIG. 1, the step S201 in the embodiment shown in FIG. 2, and the step S301 in the embodiment shown in FIG. 3, which will not be repeated here.

At S602, based on the result of determining whether to select the same PCF network element for the PDU session of the UE, the BSF network element is requested to select a PCF network element for the PDU session of the UE.

As described above based on the related description of step S101 in the embodiment of FIG. 1, the determination result may be that there is a need to select the same PCF network element serving each UE within the UE group for the PDU session of the UE, or may be that there is no need to select the same PCF network element serving each UE within the UE group for the PDU session of the UE. Based on different determination results, different registration requests may be made to the BSF network element.

In some embodiments, the step S602 may be implemented through the following steps.

At S6021, when the result indicates a need of selecting the same PCF network element for the PDU session of the UE, the BSF network element is requested to select the same PCF network element for the PDU session of the UE.

In this embodiment, for the determination result that there is a need to select the same PCF network element serving each UE within the UE group for the PDU session of the UE (that is, the first PCF network element determines to select the same PCF network element for each UE within the UE group), the first PCF network element may submit a registration request to the BSF network element to select the same PCF network element for the PDU session of the UE through the following steps.

At S60211, a registration request associated with the PDU session of the UE is sent to the BSF network element, so that the BSF network element selects the first PCF network element for the PDU session of the UE when the BSF network element determines that the first PCF network element may serve as the same PCF network element based on the registration request. The registration request includes a UE group identifier of the UE group.

For the specific implementation details of the step S60211, reference may be made to the related description of the step S50211 in the embodiment shown in FIG. 5, which will not be repeated here.

At S60212, available PCF network element information fed back by the BSF network element is received. The available PCF network element information is fed back when the BSF network element determines based on the registration request that the first PCF network element cannot serve as the same PCF network element, and the available PCF network element information is related information of the same PCF network element.

As described in the above step S60211, when the first PCF network element determines that there is a need to select the same PCF network element serving each UE within the UE group to which the UE belongs for the PDU session of the UE, the registration request carrying the UE group identifier is sent to the BSF network element, and when the BSF network element determines that the first PCF network element may serve as the same PCF network element based on the UE group identifier, the first PCF network element is selected for the PDU session of the UE.

However, if the BSF network element determines that the first PCF network element cannot serve as the same PCF network element based on the UE group identifier, the BSF network element may not select the first PCF network element for the PDU session of the UE and feed available PCF network element information back to the first PCF network element. The available PCF network element information is related information of the same PCF network element.

In some embodiments, a condition for the first PCF network element that may serve as the same PCF network element includes: binding information including the UE group identifier is registered in the BSF network element and a PCF network element indicated in the registered binding information is not the first PCF network element.

The BSF network element may determine whether the first PCF network element can serve as the same PCF network element according to a registration state of the binding information.

For example, if binding information including the UE group identifier is registered in the BSF network element, meaning that the BSF network element has selected a PCF network element for a PDU session of a UE within the UE group, it may be determined based on the registered binding information whether a PCF network element that has been selected for the PDU session of the UE in the UE group (hereinafter referred to as the “selected PCF network element”) is the first PCF network element. Usually, the binding information may record information on the selected PCF network element information. If the information on the selected PCF network element indicates that the selected PCF network element is not the first PCF network element, meaning that the same PCF network element serving each UE within the UE group is not the first PCF network element, the first PCF network element should not be selected for the PDU session of the UE. In this case, the same PCF network element serving each UE within the UE group is a PCF network element specified in the registered binding information. The BSF network element may feed back to the first PCF network element, available PCF network element information indicating related information of the PCF network element specified in the registered binding information.

S60213, the available PCF network element information is fed back to a SMF network element, so that the SMF network element may reselect the same PCF network element for the PDU session of the UE based on the available PCF network element information.

The first PCF network element receives the available PCF network element information from the BSF network element, meaning that the first PCF network element is not suitable to serve the PDU session of the UE. That is to say, the SMF network element fails to select a suitable PCF network element when selecting a PCF network element for the PDU session of the UE. In this case, the first PCF network element feeds back the available PCF network element information to the SMF network element, so that the SMF network element may reselect a suitable PCF network element for the PDU session of the UE based on the available PCF network element information. Since the available PCF network element information is related information of the same PCF network element, the SMF network element may select the same PCF network element for the PDU session of the UE based on the available PCF network element information, so as to achieve the purpose of selecting the same PCF network element for a PDU session of each UE within the same group of UEs.

By implementing this embodiment, when the PCF network element determines that there is a need to select the same PCF network element serving each UE in the UE group to which the UE belongs for the PDU session of the UE, the PCF network element sends a registration request carrying the UE group identifier of the UE group to the BSF network element, and selects the same PCF network element for the PDU session of the UE, so as to achieve the purpose of selecting the same PCF network element for each UE in the same UE group.

FIG. 7 illustrates a flowchart of a method for selecting a PCF network element according to an embodiment of the present disclosure. The method is applied to the first PCF network element. Based on the embodiment described in any one of FIG. 1 to FIG. 3, as shown in FIG. 7, the method may include but is not limited to the following steps.

At S701, when the received policy association establishment request is related to the PDU session of the UE within the UE group, it is determined whether to select the same PCF network element serving each UE within the UE group for the PDU session of the UE.

Regarding the specific implementation details of the step S701, reference may be made to the related descriptions of the step S101 in the embodiment shown in FIG. 1, the step S201 in the embodiment shown in FIG. 2, and the step S301 in the embodiment shown in FIG. 3, which will not be repeated here.

At S702, based on the result of determining whether to select the same PCF network element for the PDU session of the UE, the BSF network element is requested to select a PCF network element for the PDU session of the UE.

As described above based on the related description of step S101 in the embodiment of FIG. 1, the determination result may be that there is a need to select the same PCF network element serving each UE within the UE group for the PDU session of the UE, or may be that there is no need to select the same PCF network element serving each UE within the UE group for the PDU session of the UE. Based on different determination results, different registration requests may be made to the BSF network element.

In some embodiments, the step S702 may be implemented through the following steps.

At S7021, when the result indicates no need of selecting the same PCF network element for the PDU session of the UE, the BSF network element is requested to select the first PCF network element for the PDU session of the UE.

In this embodiment, for the determination result that there is no need to select the same PCF network element serving each UE within the UE group for the PDU session of the UE (that is, the first PCF network element determines that there is no need to select the same PCF network element for each UE within the UE group), the first PCF network element may submit a registration request to select the first PCF network element for the PDU session of the UE to the BSF network element. For example, a registration request that does not carry the UE group identifier of the UE group is sent to the BSF network element. After the BSF network element receives the registration request from the first PCF network element, since the registration request does not carry the UE group identifier, the BSF network element may select the first PCF network element for the PDU session of the UE.

By implementing this embodiment, when the PCF network element determines that there is no need to select the same PCF network element serving each UE in the UE group to which the UE belongs for the PDU session of the UE, the PCF network element submits a registration request to select a PCF network element for the PDU session of the UE to the BSF network element, so that the BSF network element may select a PCF network element for the PDU session of the UE.

FIG. 8 illustrates a flowchart of another method for selecting a PCF network element according to an embodiment of the present disclosure. The method is applied to a BSF network element. As shown in FIG. 8, the method may include but is not limited to the following steps.

At S801, a registration request is received from the first PCF network element. The registration request is related to a PDU session of a UE within a UE group and includes a UE group identifier of the UE group.

In this embodiment, for the PDU session of the UE belonging to the UE group, a SMF network element may select a PCF network element (which may be referred to as the “first PCF network element” hereafter for the sake of clarity) to serve the PDU session of the UE. For example, the SMF network element may send a policy association establishment request to the selected PCF network element. When the first PCF network element receives the policy association establishment request, the first PCF network element may send a registration request carrying the UE group identifier of the UE group to the BSF network element, so as to request a selection of the same PCF network element serving each UE within the UE group for the PDU session of the UE group.

At S802, a same PCF network element serving each UE within the UE group is selected for the PDU session of the UE based on the registration request.

After receiving the registration request carrying the UE group identifier, the BSF network element selects the same PCF network element serving each UE within the UE group for the PDU session of the UE based on the UE group identifier.

By implementing this embodiment, after receiving a registration request carrying the UE group identifier of the UE group from the PCF network element selected for the PDU session of the UE within the UE group, the BSF network element selects the same PCF network element serving each UE within the UE group for the PDU session of the UE, so as to achieve the purpose of selecting the same PCF network element for each UE within the same UE group.

FIG. 9 illustrates a flowchart of another method for selecting a PCF network element according to an embodiment of the present disclosure. The method is applied to the BSF network element. Based on the embodiment shown in FIG. 8, as shown in FIG. 9, the method may include but is not limited to the following steps.

At S901, a registration request is received from the first PCF network element. The registration request is related to a PDU session of a UE within a UE group and includes a UE group identifier of the UE group.

For the specific implementation details of the step S901, reference may be made to the related description of the step S801 in the embodiment shown in FIG. 8, which will not be repeated here.

At S902, a same PCF network element serving each UE within the UE group is selected for the PDU session of the UE based on the registration request.

After receiving the registration request carrying the UE group identifier, the BSF network element selects the same PCF network element serving each UE within the UE group for the PDU session based on the UE group identifier.

In some embodiments, the step S902 may be implemented through the following steps.

At S9021, when binding information including the UE group identifier is not registered in the BSF network element, the binding information including the UE group identifier is registered and the first PCF network element is selected for the PDU session of the UE.

Usually, after the BSF network element receives a registration request for a certain PDU session from a certain PCF network element, the BSF network element may select a PCF network element for the PDU session. However, in the disclosure, after the BSF network element receives the registration request for the PDU session of the certain UE carrying the UE group identifier from the first PCF network element, even if the registration request comes from the first PCF network element, the BSF network element will determine whether the first PCF network element may serve as the same PCF network element since the registration request carries a UE group identifier (which indicates it is expected to select for the PDU session of the UE, the same PCF network element serving each UE in the UE group to which the UE belongs). Only when the first PCF network element may serve as the same PCF network element, the BSF network element may select the first PCF network element for the PDU session of the UE.

The BSF network element may determine whether the first PCF network element may serve as the same PCF network element according to a registration state of the binding information.

For example, if the binding information including the UE group identifier is not registered in the BSF network element, meaning that the BSF network element has not selected a PCF network element for a PDU session of any UE in the UE group. In this case, any PCF network element may be selected for the PDU session of the UE. Considering that the registration request is sent by the first PCF network element, the first PCF network element may serve as the same PCF network element and the first PCF network element is selected for the PDU session of the UE.

By implementing this embodiment, after the BSF network element receives a registration request carrying the UE group identifier of the UE group from the PCF network element selected for the PDU session of the UE within the UE group, if binding information including the UE group identifier is not registered in the BSF network element, the PCF network element is selected for the PDU session of the UE.

FIG. 10 illustrates a flowchart of another method for selecting a PCF network element according to an embodiment of the present disclosure. This method is applied to the BSF network element. Based on the embodiment shown in FIG. 8, as shown in FIG. 10, the method may include but is not limited to the following steps.

At S1001, a registration request is received from the first PCF network element. The registration request is related to a PDU session of a UE within a UE group and includes a UE group identifier of the UE group.

Regarding the specific implementation details of the step S1001, reference may be made to the related description of the step S801 in the embodiment shown in FIG. 8, which will not be repeated here.

At S1002, a same PCF network element serving each UE within the UE group is selected for the PDU session of the UE based on the registration request.

After receiving the registration request carrying the UE group identifier, the BSF network element selects the same PCF network element serving each UE within the UE group for the PDU session of the UE based on the UE group identifier.

In some embodiments, the step S1002 can be implemented by the following steps.

At S10021, when the binding information including the UE group identifier is registered in the BSF network element and a PCF network element indicated in the registered binding information is the first PCF network element, the first PCF network element is selected for the PDU session of the UE.

In the disclosure, after the BSF network element receives a registration request carrying the UE group identifier for a PDU session of a certain UE from the first PCF network element, even if the registration request comes from the first PCF network element, the BSF network element will determine whether the first PCF network element may serve as the same PCF network element since the registration request carries a UE group identifier (which indicates it is expected to select for the PDU session of the UE, the same PCF network element serving each UE in the UE group to which the UE belongs). Only when the first PCF network element may serve as the same PCF network element, the BSF network element may select the first PCF network element for the PDU session of the UE.

The BSF network element may determine whether the first PCF network element may serve as the same PCF network element according to a registration state of the binding information.

For example, if the binding information including the UE group identifier is registered in the BSF network element, meaning that the BSF network element has selected a PCF network element for a PDU session of a UE in the UE group, it may be determined based on the registered binding information whether the PCF network element that has been selected for the PDU session of the UE within the UE group (hereinafter referred to as the “selected PCF network element”) is the first PCF network element. Usually, the binding information may record information on the selected PCF network element. If the information on the selected PCF network element indicates that the selected PCF network element is the first PCF network element, meaning that the same PCF network element serving each UE within the UE group is the first PCF network element, the first PCF network element may be selected for the PDU session of the UE.

By implementing this embodiment, after the BSF network element receives a registration request carrying the UE group identifier of the UE group from the PCF network element selected for the PDU session of the UE within the UE group, if the binding information including the UE group identifier is already registered in the BSF network element and a PCF network element specified in the registered binding information is the selected PCF network element, then the PCF network element is selected for the PDU session of the UE.

FIG. 11 illustrates a flowchart of another method for selecting a PCF network element according to an embodiment of the present disclosure. The method is applied to the BSF network element. Based on the embodiment shown in FIG. 8, as shown in FIG. 11, the method may include but is not limited to the following steps:

At S1101, a registration request is received from the first PCF network element. The registration request is related to a PDU session of a UE within a UE group and includes a UE group identifier of the UE group.

Regarding the specific implementation details of above step S1101, reference may be made to the related description of the step S801 in the embodiment shown in FIG. 8, which will not be repeated here.

At S1102, a same PCF network element serving each UE within the UE group is selected for the PDU session of the UE based on the registration request.

After receiving the registration request carrying the UE group identifier, the BSF network element selects the same PCF network element serving each UE within the UE group for the PDU session based on the UE group identifier.

In some embodiments, the step S1102 can be implemented by the following steps.

At S11021, when the binding information including the UE group identifier is registered in the BSF network element and a PCF network element indicated in the registered binding information is not the first PCF network element, available PCF network element information is fed back to the first PCF network element, so that the first PCF network element feeds back the available PCF network element information to the SMF network element and the SMF network element may reselect a same PCF network element for the PDU session of the UE. The available PCF network element information is related information of the PCF network element indicated in the registered binding.

In the disclosure, after the BSF network element receives a registration request carrying the UE group identifier for a PDU session of a certain UE from the first PCF network element, even if the registration request comes from the first PCF network element, the BSF network element will determine whether the first PCF network element may serve as the same PCF network element since the registration request carries a UE group identifier (which indicates it is expected to select for the PDU session of the UE, the same PCF network element serving each UE within the UE group to which the UE belongs). Only when the first PCF network element may serve as the same PCF network element, the BSF network element may select the first PCF network element for the PDU session of the UE.

However, if the BSF network element determines that the first PCF network element cannot serve as the same PCF network element based on the UE group identifier, the BSF network element may not select the first PCF network element for the PDU session of the UE.

The BSF network element may determine whether the first PCF network element may serve as the same PCF network element according to a registration state of the binding information.

For example, if the binding information including the UE group identifier is registered in the BSF network element, meaning that the BSF network element has selected a PCF network element for a PDU session of a UE within the UE group, it may be determined based on the registered binding information whether a PCF network element that has been selected for the PDU session of the UE within the UE group (hereinafter referred to as the “selected PCF network element”) is the first PCF network element. Usually, the binding information may record information on the selected PCF network element. If the information on the selected PCF network element indicates that the selected PCF network element is not the first PCF network element, meaning that the same PCF network element serving each UE within the UE group is not the first PCF network element, the first PCF network element should not be selected for the PDU session of the UE. In this case, the same PCF network element serving each UE within the UE group is the PCF network element specified in the registered binding information. The BSF network element may feed back to the first PCF network element, available PCF network element information indicating related information of the PCF network element indicated in the registered binding information.

The first PCF network element receives the available PCF network element information from the BSF network element, meaning that the first PCF network element is not suitable to serve he PDU session of the UE. That is to say, the SMF network element fails to select a suitable PCF network element when selecting a PCF network element for the PDU session of the UE. In this case, the first PCF network element feeds back the available PCF network element information to the SMF network element, so that the SMF network element may reselect a suitable PCF network element for the PDU session of the UE based on the available PCF network element information. Since the available PCF network element information is related information of the same PCF network element, the SMF network element may select the same PCF network element for the PDU session of the UE based on the available PCF network element information, so as to achieve the purpose of selecting the same PCF network element for a PDU session of each UE within the same group of UEs.

By implementing this embodiment, after the BSF network element receives a registration request carrying the UE group identifier of the UE group from the PCF network element selected for the PDU session of the UE within the UE group, if the binding information including the UE group identifier is already registered in the BSF network element and the selected PCF network element specified in the registered binding information is not the PCF network element, then the available PCF network element information is fed back to the PCF network element for the purpose of reselecting a PCF network element.

FIG. 12 illustrates a flowchart of another method for selecting a PCF network element according to an embodiment of the present disclosure. The method is applied to the BSF network element. Based on the embodiment shown in any one of FIG. 8 to FIG. 11, as shown in FIG. 12, the method may include but is not limited to the following steps.

At S1201, a registration request is received from the first PCF network element. The registration request is related to a PDU session of a UE within a UE group and includes a UE group identifier of the UE group.

Regarding the specific implementation details of the step S1201, reference may be made to the related description of the step S801 in the embodiment shown in FIG. 8, which will not be repeated here.

At S1202, a same PCF network element serving each UE within the UE group is selected for the PDU session of the UE based on the registration request.

After receiving the registration request carrying the UE group identifier, the BSF network element selects the same PCF network element serving each UE within the UE group for the PDU session of the UE based on the UE group identifier.

For the specific implementation details of the step S1202, reference may be made to the step S802 in the embodiment shown in FIG. 8, the step S902 in the embodiment shown in FIG. 9, the step S1002 in the embodiment shown in FIG. 10 and the step S1102 in the embodiment shown in FIG. 11, which will not be repeated here.

At S1203, when the UE group identifier is carried in a received policy request related to an AF session of the UE within the UE group, the same PCF network element is selected for the AF session based on the UE group identifier.

In this embodiment, for the AF session of a UE belonging to the UE group, the AF network element may send a policy request to the BSF network element to select an appropriate PCF network element to serve the AF session. If the policy request received by the BSF network element carries the UE group identifier of the UE group, meaning that it is expected to select the same PCF network element serving each UE within the UE group for this AF session, the BSF network element may thus select the same PCF network element for the AF session.

By implementing this embodiment, after receiving the policy request carrying the UE group identifier of the UE group from the AF network element, the BSF network element selects the same PCF network element serving each UE within the UE group for the AF session of the UE, so as to achieve the purpose of selecting the same PCF network element for each UE in the same UE group.

FIG. 13 illustrates a flowchart of another method for selecting a PCF network element according to an embodiment of the present disclosure. The method is applied to an AF network element. As shown in FIG. 13, the method may include but is not limited to the following steps.

At S1301, when an AF session is initiated for a UE within a UE group, a policy request carrying a UE group identifier of the UE group is sent to a BSF network element, so that the BSF network element selects a same PCF network element serving each UE within the UE group for the AF session of the UE based on the UE group identifier.

In this embodiment, for an AF session of a UE belonging to the UE group, the AF network element may send a policy request carrying a UE group identifier of the UE group to the BSF network element, so as to select a same PCF network element serving each UE within the UE group for the AF session. If the policy request received by the BSF network element carries the UE group identifier of the UE group, meaning that it is expected to select the same PCF network element serving each UE in the UE group for the AF session, the BSF network element may thus select the same PCF network element for the AF session.

In some embodiments, the UE group identifier is stored in a user description of the UE in the UDR.

The user description of the UE stored in the UDR may record a UE group identifier of a UE group to which the UE belongs, so that any network device in need may obtain a UE group identifier of a UE group to which a UE belongs by querying a user description of the UE stored in the UDR. For example, when the AF network element determines that there is a need to select the same PCF network element serving each UE in the UE group to which the UE belongs for the AF session of the UE, the AF network element may obtain the UE group identifier of the UE group by querying the user description of the UE stored in the UDR, enable the UE group identifier to be carried in the policy request and send to the BSF network element, so as to request to select the same PCF network element for the AF session of the UE.

In some embodiments, the user description also indicates whether the UE is subscribed to a service requiring group policy coordination.

By implementing this embodiment, for an AF session of a UE belonging to a UE group, the AF network element sends a policy request carrying a UE group identifier of the UE group to the BSF network element, so that the BSF network element selects for the AF session of the UE, the same PCF network element serving each UE within the UE group, so as to achieve the purpose of selecting the same PCF network element for each UE within the same UE group.

In the above-mentioned embodiments according to the disclosure, the methods according to the embodiments of the disclosure are introduced from the perspectives of different network devices. In order to implement each function in the methods according to the above embodiments of the disclosure, the network device may include a hardware structure and a software module to implement the above functions in the form of a hardware structure, a software module, or a hardware structure plus a software module. One of the above functions may be implemented in the form of a hardware structure, a software module, or a hardware structure plus a software module

Corresponding to the method for selecting a PCF network element according to the above several embodiments, the present disclosure also provides an apparatus for selecting a PCF network element. As the apparatus for selecting a PCF network element according to the embodiments of the present disclosure corresponds to the method for selecting a PCF network element according to the above several embodiments, specific implementations of the method for selecting a PCF network element are also applicable to the apparatus for selecting a PCF network element according to the embodiments, which will not be repeated in detail in this embodiment. FIG. 14 to FIG. 17 are structural diagrams of the apparatus for selecting a PCF network element according to the present disclosure.

FIG. 14 is a structural diagram of an apparatus 1400 for selecting a PCF network element according to an embodiment of the present disclosure. The apparatus is applied to the first PCF network element.

As shown in FIG. 14, the apparatus 1400 for selecting a PCF network element includes: a determination module 1401, and a sending module 1402.

The determination module 1401 is configured to in response to a received policy association establishment request being related to a PDU session of a UE within a UE group, determine whether to select a same PCF network element serving each UE in the UE group for the PDU session of the UE.

The sending module 1402 is configured to request a BSF network element to select a PCF network element for the PDU session of the UE based on a result of determining whether to select the same PCF network element for the PDU session of the UE.

By implementing this embodiment, the PCF network element provides a PCF network element selection method that the same PCF network element is selected for each UE within the same UE group by determining whether to select the same PCF network element for each UE in the same UE group, which avoids an interaction process between a plurality of PCF network elements serving the same UE group.

In some embodiments, the determination module 1401 is configured to: obtain a user description of the UE from a UDR, in which the user description indicates whether the UE is subscribed to a service requiring group policy coordination; and determine whether to select the same PCF network element for the PDU session of the UE based on the user description.

In some embodiments, the determination module 1401 is configured to: determine whether to select the same PCF network element for the PDU session of the UE based on a local policy in the first PCF network element, in which the local policy indicates whether each UE belonging to a same UE group is served by a same PCF network element.

In some embodiments, the sending module 1402 is configured to: in response to the result indicating a need of selecting the same PCF network element for the PDU session of the UE, request the BSF network element to select the same PCF network element for the PDU session of the UE.

In some embodiments, the sending module 1402 requests the BSF network element to select the same PCF network element for the PDU session of the UE by: sending a registration request associated with the PDU session of the UE to the BSF network element, so that the BSF network element determines based on the registration request that the first PCF network element may serve as the same PCF network element and selects the first PCF network element for the PDU session of the UE, in which the registration request includes a UE group identifier of the UE group.

In some embodiments, a condition for the first PCF network element to serve as the same PCF network element includes one of: binding information including the UE group identifier is not registered in the BSF network element; or binding information including the UE group identifier is registered in the BSF network element and a PCF network element indicated in the registered binding information is the first PCF network element.

In some embodiments, as shown in FIG. 15, the apparatus 1400 further includes a receiving module 1403, configured to receive available PCF network element information fed back by the BSF network element, in which the available PCF network element information is fed back when the BSF network element determines based on the registration request that the first PCF network element cannot serve as the same PCF network, and the available PCF network element information is related information of the same PCF network element.

The sending module 1402 is further configured to: feed the available PCF network element information back to a SMF network element, so that the SMF network element reselects the same PCF network element for the PDU session of the UE based on the available PCF network element information.

In some embodiments, a condition that the first PCF network element cannot serve as the same PCF network element includes: binding information including the UE group identifier is registered in the BSF network element and a PCF network element indicated in the registered binding information is not the first PCF network element. The same PCF network element is the PCF network element indicated in the registered binding information.

In some embodiments, the UE group identifier is obtained by querying a user description of the UE stored in the UDR.

In some embodiments, the sending module 1402 is configured to: in response to the result indicating no need of selecting the same PCF network element for the PDU session of the UE, request the BSF network element to select the first PCF network element for the PDU session of the UE.

FIG. 16 is a structural diagram of another apparatus 1600 for selecting a PCF network element according to an embodiment of the present disclosure. The apparatus is applied to the BSF network element.

As shown in FIG. 16, the apparatus 1600 for selecting a PCF network element includes: a receiving module 1601, and a registration module 1602.

The receiving module 1601 is configured to receive a registration request from a first PCF network element, in which the registration request is related to a PDU session of a UE within a UE group and includes a UE group identifier of the UE group.

The registration module 1602 is configured to select a PCF network element for the PDU session of the UE based on the registration request.

By implementing this embodiment, after receiving a registration request carrying the UE group identifier of the UE group from the PCF network element selected for the PDU session of the UE within the UE group, the BSF network element selects he same PCF network element serving each UE within the UE group for the PDU session of the UE, so as to achieve the purpose of selecting the same PCF network element for each UE within the same UE group.

In some embodiments, the registration module 1602 is configured to: in response to binding information including the UE group identifier being not registered in the BSF network element, register the binding information including the UE group identifier and select the first PCF network element for the PDU session of the UE.

In some embodiments, the registration module 1602 is configured to: in response to binding information including the UE group identifier being registered in the BSF network element and a PCF network element indicated in the registered binding information being the first PCF network element, select the first PCF network element for the PDU session of the UE.

In some embodiments, the registration module 1602 is configured to: in response to the binding information including the UE group identifier being registered in the BSF network element and a PCF network element indicated in the registered binding information is not the first PCF network element, feed back available PCF network element information to the first PCF network element, so that the first PCF network element may feed back the available PCF network element information to the SMF network element and the SMF network element may reselect the same PCF network element for the PDU session of the UE, in which the available PCF network element information is related information of the PCF network element indicated in the registered binding information.

In some embodiments, the registration module 1602 is configured to: in response to the UE group identifier being carried in a received policy request related to an AF session of the UE within the UE group, select the same PCF network element for the AF session based on the UE group identifier.

FIG. 17 is a structural diagram of another apparatus 1700 for selecting a PCF network element according to an embodiment of the present disclosure. The apparatus is applied to the AF network element.

As shown in FIG. 17, the apparatus 1700 for selecting a PCF network element includes: a sending module 1701.

The sending module 1701 is configured to in response to an AF session being initiated for a UE within a UE group, send a policy request carrying a UE group identifier of the UE group to a BSF network element, so that the BSF network element selects a PCF network element based on the policy request for the AF session of the UE.

By implementing this embodiment, for the AF session of the UE belonging to the UE group, the AF network element sends a policy request carrying the UE group identifier of the UE group to the BSF network element, so that the BSF network element selects the same PCF network element serving each UE within the UE group for the AF session of the UE, so as to achieve the purpose of selecting the same PCF network element for each UE within the same UE group.

In some embodiments, the UE group identifier is stored in a user description of the UE in a UDR.

In some embodiments, the user description also indicates whether the UE is subscribed to a service requiring group policy coordination.

Referring to FIG. 18, it is a structural diagram of another communication device 1800 according to an embodiment of the disclosure. The communication device 1800 may be a network device, or a user device, or a chip, a chip system or a processor that supports a network device to implement the above method, or a chip, a chip system or a processor that supports a terminal to implement the above method. The device can be used to implement the method described in the above method embodiments. For details, please refer to the description in the above method embodiments.

The communication device 1800 may include one or more processors 1801. The processor 1801 may be a general purpose processor or a special purpose processor or the like. For example, it may be a baseband processor or a central processing unit. The baseband processor may be used to process communication protocols and communication data. The central processor can be used to control a communication device (such as a base station, a baseband chip, a terminal, a terminal chip, a DU or a CU, etc.), execute computer programs and process data for computer programs.

Optionally, the communication device 1800 may further include one or more memories 1802, on which a computer program 1804 may be stored. The processor 1801 executes the computer program 1804, so that the communication device 1800 executes the method described in the foregoing method embodiments. Optionally, the memory 1802 may also store data. The communication device 1800 and the memory 1802 can be provided separately or integrated together.

Optionally, the communication device 1800 may also include a transceiver 1805 and an antenna 1806. The transceiver 1805 may be called a transceiver unit, a transceiver, a transceiver circuit, etc., which is used to implement transmission and reception functions. The transceiver 1805 may include a receiver and a transmitter, and the receiver may be called a receiver or a receiving circuit for realizing a reception function; the transmitter may be called a transmitter or a transmission circuit for realizing a transmission function.

Optionally, the communication device 1800 may further include one or more interface circuits 1807. The interface circuit 1807 is used to receive code instructions and transmit them to the processor 1801. The processor 1801 runs the code instructions to enable the communication device 1800 to execute the methods described in the foregoing method embodiments.

When the communication device 1800 is a network device, such as a PCF network element, the processor 1801 is used to execute the step S101 in FIG. 1, the step S2012 in FIG. 2, the step S3011 in FIG. 3, the step S401 in FIG. 4, the step S501 in FIG. 5, the step S601 in FIG. 6, the step S701 in FIG. 7. The transceiver 1805 is used to perform the step S102 in FIG. 1, the steps S2011 and S202 in FIG. 2, the step S302 in FIG. 3, the step S4021 in FIG. 4, the step S50211 in FIG. 5, the steps S60211-S60213 in FIG. 6, and the step S7021 in FIG. 7.

When the communication device 1800 is a network device, such as a BSF network element, the processor 1801 is used to execute the step S802 in FIG. 8, the step S9021 in FIG. 9, the step S10021 in FIG. 10, the step S11021 in FIG. 11, and the steps S1202-S1203 in FIG. 12. The transceiver 1805 is used to execute the step S801 in FIG. 8, the step S901 in FIG. 9, the step S1001 in FIG. 10, the step S1101 in FIG. 11, and the step S1201 in FIG. 12.

When the communication device 1800 is a network device, such as an AF network element, the transceiver 1805 is used to execute the step S1301 in FIG. 13.

In an implementation, the processor 1801 may include a transceiver for implementing receiving and sending functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuits, interfaces or interface circuits used to implement the receiving and transmitting functions may be separate or integrated together. The above-mentioned transceiver circuits, interfaces or interface circuits may be used for reading and writing codes/data, or the above-mentioned transceiver circuits, interfaces or interface circuits can be used for signal transmission or transfer.

In an implementation, the processor 1801 may store a computer program 1803. When the computer program 1803 is running on the processor 1801, the communication device 1800 is caused to perform the method described in the above method embodiments. The computer program 1803 may be solidified in the processor 1801, in which case the processor 1801 may be implemented in hardware.

In an implementation, the communication device 1800 may include a circuit that may implement the function of sending or receiving or communicating in the foregoing method embodiments. The processors and transceivers described in the disclosure may be implemented on integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed-signal ICs, application specific integrated circuits (ASICs), printed circuit boards (PCBs), electronic devices, etc. The processor and transceiver may also be manufactured using various IC process technologies, such as a complementary metal oxide semiconductor (CMOS), a nMetal-oxide-semiconductor (NMOS), a positive channel metal oxide semiconductor (PMOS), a bipolar junction transistor (BJT), a bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

The communication device described in the above embodiments may be a network device or a terminal device (such as the first terminal device in the foregoing method embodiments), but the scope of the communication device described in the disclosure is not limited, and the structure of the communication device can be not limited by FIG. 18. The communication device may be a stand-alone device or may be part of a larger device. For example, the communication device may be:

- (1) an independent integrated circuit IC, or a chip, or a chip system or a subsystem;
- (2) a collection of one or more ICs. Optionally, the IC collection may also include storage components for storing data and computer programs;
- (3) ASIC, such as modem;
- (4) modules that can be embedded in other devices;
- (5) a receiver, a terminal device, an intelligent terminal device, a cellular phone, a wireless device, a handheld device, a mobile unit, a vehicle-mounted device, a network device, a cloud device, an artificial intelligence device, etc.;
- (6) Others, etc.

For the case where the communication device may be a chip or a chip system, refer to the structural diagram of the chip shown in FIG. 19. The chip shown in FIG. 19 includes a processor 1901 and an interface 1902. The number of processors 1901 may be one or more, and a number of interfaces 1902 may be multiple.

For the case where the chip is used to implement the functions of the network device in the embodiments of the disclosure, such as the PCF network element, the processor 1901 is used to execute the step S101 in FIG. 1, the step S2012 in FIG. 2, the step S3011 in FIG. 3, the step S401 in FIG. 4, the step S501 in FIG. 5, the step S601 in FIG. 6, and the step S701 in FIG. 7. The processor 1901 is configured to execute, via the interface 1902, the step S102 in FIG. 1, the steps S2011 and S202 in FIG. 2, the step S302 in FIG. 3, the S4021 in FIG. 4, the step S50211 in FIG. 5, the steps S60211-S60213 in FIG. 6, and the step S7021 in FIG. 7.

For the case where the chip is used to implement the functions of the network equipment in the embodiment of the disclosure, such as the BSF network element, the processor 1901 is used to execute, via the interface 1902, the step S802 in FIG. 8, the step S9021 in FIG. 9, the step S10021 in FIG. 10, the step S11021 in FIG. 11 and the steps S1202-S1203 in FIG. 12. The processor 1901 is configured to execute the step S801 in FIG. 8, the step S901 in FIG. 9, the step S1001 in FIG. 10, the S1101 in FIG. 11, and the step S1201 in FIG. 12.

For the case where the chip is used to implement the functions of the network device in the embodiment of the disclosure, such as the AF network element, the processor