IP address allocation in wireless communication networks

Abstract

A method performed by a user plane core network function for a wireless communication network is provided. The user plane core network function is configured with an Internet Protocol address range for allocation to user equipment. The method comprises sending a message to a control plane core network function, the message comprising an indication of a usage level of the IP address range. A corresponding network node is also provided.

Description

[0001] This application is a divisional application of the Chinese national phase application (application number 202180037185.1) of PCT international application PCT / CN2021 / 094846 entitled “IP ADDRESS ALLOCATION IN A WIRELESS COMMUNICATION NETWORK”, filed on May 20, 2021. Technical Field

[0002] Embodiments of this disclosure generally relate to communications, and more specifically to methods and apparatus relating to IP address allocation in wireless communication networks. Background Technology

[0003] This section introduces aspects that may help in a better understanding of this disclosure. Therefore, the statements in this section should be read in this context and should not be construed as an admission of anything present in or not present in the prior art.

[0004] When a User Equipment (UE) connects to a wireless communication network, an Internet Protocol (IP) address is assigned to the UE by the core network to enable a simple data connection between the UE and the Packet Data Network (PDN). Prior to Release 16 of the 3GPP specification, IP addresses were assigned to the UE through control plane functions in the core network, such as the PDN Gateway (PGW-C) in the control plane. Release 16 of the 3GPP specification introduced the use of User Plane (UP) functions to assign UE IP addresses.

[0005] Therefore, the UP function can manage and allocate UE addresses for each PDN or Protocol Data Unit (PDU) session. The UP function receives session establishment requests (e.g., Packet Forwarding Control Protocol (PFCP) session establishment requests) from control plane (CP) functions, allocates UE IP addresses, and sends them to the CP function in a PFCP session establishment response. For example, the CP function could be a PDN gateway (PGW-C) or a Session Management Function (SMF) in the control plane.

[0006] The details of this process are elaborated in 3GPP Technical Specification (TS) 29.244 v 16.3.1, as follows (see Section 5.21.3):

[0007] When performing UE IP address / prefix allocation in the UP function, the CP function should request the UP function to allocate the UE IP address / prefix in the following manner:

[0008] - Set the selection flag (select IPv4 and / or select IPv6) in the UE IP address information element (IE) of the Packet Detection Rule (PDR) IE (see Table 7.5.2.2-1) or Service Endpoint (see Table 7.5.2.7-1); if an IPv6 prefix other than the default / 64 and for use with an IPv6 prefix proxy (see Clause 5.14) are to be assigned and the User Plane Function (UPF) indicates support for the IP6PL feature (see Clause 8.2.25), then the IPv6 prefix length should be indicated in the UE IP address; and

[0009] - Includes network instance IE to indicate the IP address pool from which to allocate UE IP addresses / prefixes.

[0010] -Optionally include the UE IP address pool identifier that the UP function should use to allocate UE IP addresses.

[0011] The CP function can request the UP function to assign the same UE address / prefix to several PDRs that will be created in a single PFCP session establishment request or PFCP session modification request in the following way:

[0012] - Set the selection flag (select IPv4 and / or select IPv6) in the UE IP address IE of each PDR to be created with the new UE IP address / prefix;

[0013] Alternatively, if the UP function indicates support for optimized Packet Detection Information (PDI) (see Clause 8.2.25), then it is done as follows:

[0014] - Include the UE IP address IE only when creating the service endpoint IE, and set the selection flag (select IPv4 and / or select IPv6) in the UE IP address IE of this IE; and

[0015] - Include the service endpoint ID in all PDRs that will be created using the same UE IP address.

[0016] If the PDR is created successfully, the UP function should return the UE IP address / prefix it assigns to the PDR or to the service endpoint in the PFCP session establishment response or PFCP session modification response.

[0017] Upon receiving a request to delete a PFCP session, remove a service endpoint, or remove the last PDR associated with a UE IP address / prefix, the UP function should release the UE IP address / prefix assigned to the PFCP session, service endpoint, or PDR.

[0018] Therefore, embodiments of this disclosure can be implemented in a 5G core network. Figure 1The architecture for a 5G system is illustrated. As shown in the figure, a 5G system includes User Equipment (UE), (R)Access Network ((R)AN), User Plane Function (UPF), Data Network (DN), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), Serving Communication Broker (SCP), Network Slice Selection Function (NSSF), Network Open Function (NEF), Network Repository Function (NRF), Policy Control Function (PCF), Unified Data Management (UDM), and Application Function (AF).

[0019] The 5G architecture is defined as service-based, and the interactions between network functions (NFs) are represented in two ways. One way is the service-based representation, where an NF within the control plane (e.g., an AMF) enables other authorized NFs to access its services. This representation also includes point-to-point reference points where necessary. The other way is the reference point representation, which shows the interactions between NF services in the NFs described by point-to-point reference points (e.g., N11) between any two NFs (e.g., AMF and SMF).

[0020] NEF supports the external exposure of NF capabilities. External exposure can be categorized into monitoring capabilities, provisioning capabilities, policy / charging capabilities, and analytics reporting capabilities. Monitoring capabilities are used to monitor specific events related to the UE in the 5G system and make this monitoring event information available for external exposure via NEF. Provisioning capabilities allow external parties to provide information that can be used by the UE in the 5G system. Policy / charging capabilities are used to process the UE's Quality of Service (QoS) and charging policies based on external party requests. Analytics reporting capabilities allow external parties to obtain or subscribe to / unsubscribe from analytics information generated by the 5G system. Summary of the Invention

[0021] This summary is provided to introduce a series of concepts in a simplified form, which are further described in the detailed embodiments below. This summary is not intended to define the key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0022] One of the purposes of this disclosure is to reduce the waste of network resources and delays caused by failed requests for UE IP address allocation performed by the UP function.

[0023] According to a first aspect of this disclosure, a method is provided performed by a user plane core network function for a wireless communication network. The user plane core network function is configured with IP address ranges for allocation to a UE. The method includes sending a message to a control plane core network function. The message includes an indication of the usage level of the IP address range.

[0024] According to a second aspect of this disclosure, a method is provided performed by a control plane core network function for a wireless communication network. The method includes receiving messages from one or more user plane core network functions. The user plane core network functions are configured with corresponding IP address ranges for allocation to a UE. At least one of the messages includes an indication of a usage level for the IP address range. The method further includes selecting a user plane core network function to allocate an IP address to the UE based on the indicated usage level.

[0025] The technical advantage of the embodiments disclosed herein is that it reduces the likelihood of failure when requesting the UP function to assign an IP address to the UE. This reduces the latency in establishing a PDU / PDN session for the UE and allows for more efficient utilization of network resources. Attached Figure Description

[0026] These and other objects, features, and advantages of this disclosure will become apparent from the following detailed description of illustrative embodiments, which will be understood in conjunction with the accompanying drawings.

[0027] Figure 1 It is a diagram illustrating the architecture used in 5G systems;

[0028] Figure 2 This is a signaling diagram illustrating signaling according to an embodiment of the present disclosure;

[0029] Figure 3 This is a signaling diagram illustrating signaling according to other embodiments of this disclosure;

[0030] Figure 4 This is a signaling diagram illustrating signaling according to other embodiments of this disclosure;

[0031] Figure 5 This is a signaling diagram illustrating signaling according to other embodiments of this disclosure;

[0032] Figure 6 This is a flowchart illustrating a method implemented at a user plane core network function according to an embodiment of the present disclosure;

[0033] Figure 7 This is a flowchart illustrating a method implemented at the core network function of the control plane according to an embodiment of the present disclosure;

[0034] Figure 8 This is a block diagram illustrating an apparatus suitable for practicing some embodiments of the present disclosure;

[0035] Figure 9 This is a block diagram illustrating a user plane entity according to an embodiment of the present disclosure;

[0036] Figure 10This is a block diagram illustrating a control plane entity according to an embodiment of the present disclosure;

[0037] Figure 11 The structure of a node report type IE according to an embodiment of this disclosure is shown; and

[0038] Figure 12 The structure of the IE according to an embodiment of this disclosure is shown. Detailed Implementation

[0039] For purposes of explanation, details are set forth in the following description in order to provide a thorough understanding of the disclosed embodiments. However, it will be apparent to those skilled in the art that various embodiments may be implemented without these specific details or with equivalent arrangements.

[0040] One problem identified by the inventors concerns UE IP address allocation by UP core network functions (such as 3GPP-defined User Plane Functions (UPF) and PGW-U). UP functions configured to provide this functionality have a limited range of IP addresses for dynamic allocation to the UE. However, a CP function requesting UE IP address allocation may not know whether this range is already exhausted or about to be exhausted in the UP function; the CP function may still select the UP function to allocate an IP address to the UE. If all dynamic IP addresses are occupied (e.g., already allocated to other UEs), or if all dynamic IP addresses in the UE IP address pool indicated by the CP function are occupied, the UP function will reject the PFCP session establishment request. Therefore, IP address allocation to the UE is delayed, and network resources are wasted (e.g., used in failed requests for IP address allocation). Even after such failed requests, the CP function can still continue to select the UP function for UE IP address allocation because the request may have been rejected for reasons other than all dynamic IP addresses being occupied.

[0041] This disclosure proposes an improved solution for UE IP address allocation by UP core network functions. As an exemplary example, this solution can be applied to... Figure 1 The communication system shown. Figure 1 The functional descriptions of the entities shown are detailed in section 6 of 3GPP TS 23.501 v 16.4.0 (the entire contents of which are incorporated herein by reference). Alternatively, the embodiments may be implemented in other networks that include a separation between the user plane and the control plane, and in which the user plane is used to assign IP addresses to wireless devices.

[0042] It should be noted that, within the context of this disclosure, the term "terminal device" (or UE) as used herein may also be referred to as, for example, an access terminal, mobile station, mobile unit, subscriber station, etc. It can refer to any (fixed or mobile) terminal device that can access a wireless communication network and receive services from it. By way of example and not limitation, a UE may include a portable computer, an image capture terminal device (such as a digital camera), a gaming terminal device, a music storage and playback device, a mobile phone, a cellular phone, a smartphone, a tablet computer, a wearable device, a personal digital assistant (PDA), an integrated or embedded wireless network card, an externally inserted wireless network card, etc.

[0043] In Internet of Things (IoT) scenarios, a terminal device (or UE) can represent a machine or other device that performs monitoring and / or measurement and sends the results of such monitoring and / or measurement to another terminal device (or UE) and / or network device. In this context, the terminal device (or UE) can be a machine-to-machine (M2M) device, which, in the 3GPP context, can be referred to as a machine-type communication (MTC) device. Specific examples of such machines or devices can include sensors, metering devices (such as power meters), industrial machinery, bicycles, vehicles, or household or personal appliances (e.g., refrigerators, televisions), personal wearable devices (such as watches), etc.

[0044] As used herein, the term "communication system" refers to a system that conforms to any suitable communication standard, such as first-generation (1G), 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communication protocols, and / or any other currently known or to be developed in the future. Furthermore, communication between terminal devices and network nodes (or network entities) in a communication system can be performed according to any suitable generated communication protocol, including but not limited to 1G, 2G, 2.5G, 2.75G, 3G, 4G, 4.5G, 5G communication protocols, and / or any other currently known or to be developed in the future. Moreover, the specific terminology used herein does not limit this disclosure to communication systems in relation to the specific terminology used; however, these terms can be applied more generally to other communication systems.

[0045] As used herein, the term "UP core network function" refers to core network functions in the user plane, and includes UPF and PGW-U as examples. The term "UP function" is also used for this purpose. The acronym "UPF" explicitly refers to core network functions defined in 3GPP specifications as user plane functions, such as in section 6.2.3 of 3GPP TS 23.501 v 16.4.0. The terms "CP function" and "CP core network function" are synonyms and refer to core network functions in the control plane, such as PGW-C and SMF.

[0046] Therefore, as mentioned above, such as Figure 1 The UP function in the illustrated wireless communication network can be configured with a range of IP addresses for allocation to the UE. Upon receiving a request message from the CP function, the UP function allocates an available IP address from its IP address range and sends a response message including an indication of the allocated IP address. However, the IP address range may be exhausted, thus preventing the UP function from allocating any more IP addresses to the UE.

[0047] According to embodiments of this disclosure, the UP function is configured to send a message to the CP function including an indication of the usage level of its IP address range. In this way, the CP function is informed of the usage level in the UP function and can take this into account when selecting the UP function in the future to request IP address allocation to the UE. For example, the CP function may choose not to select (or select with a lower frequency or probability) the UP function that reports a high usage level or a lack of available IP addresses.

[0048] Indications of usage levels can include a proportion of the currently allocated range of IP addresses, such as a percentage. This proportion can be implicit or explicit. For example, in the former case, the indication could be a proportion of the currently available range of IP addresses. Since IP addresses can be either allocated or available, an indication of the former is an implicit indication of the latter, and vice versa.

[0049] The indication of usage levels may additionally or alternatively include the absolute number of available IP addresses within the range. Similarly, the indication of absolute numbers can be implicit or explicit. For example, in the former case, the indication could include an indication of the total number of IP addresses (available and allocated) within the range and the number of allocated IP addresses. Therefore, the number of available IP addresses can be derived from these numbers through subtraction.

[0050] The message may include a response message in response to a request from the CP function to assign an IP address to the UE. An example of this embodiment is shown below. Figure 2 and Figure 3 As shown below. For example, an indication of usage level can be included in such a message in response to a usage level exceeding a threshold. In this way, network resources are not used to report usage levels unless and until the usage level reaches a value at which a request to assign an IP address to the UE might be rejected because all IP addresses have already been assigned. Alternatively, the message can be sent autonomously by the UP function, for example, in response to a subscription request from the CP function. In this case, the message can be sent, for example, in response to a usage level exceeding a threshold. An example of this embodiment is shown below. Figure 4 and Figure 5 As shown in the image.

[0051] The IP address range configured in the UP function can include one or more UE IP address pools. Each UE IP address pool can be associated with a specific network instance configured in the UP function. In other words, each network instance of the UP function can be associated with one or more UE IP address pools.

[0052] An IP address can be assigned to the UE for each PDN or PDU session, for example, when such a session is established. Therefore, if a UE has multiple PDN or PDU sessions, it can have multiple IP addresses.

[0053] Additionally or alternatively, some embodiments provide a mechanism by which the UP function can report that the failure to allocate an IP address to the UE is due to the exhaustion of the IP address range in the UP function.

[0054] Figure 2 This is a signaling diagram illustrating the signaling between CP and UP functions according to embodiments of the present disclosure. For example, the CP function may correspond to PGW-C or SMF. For example, the UP function may correspond to PGW-U or UPF. In one embodiment where the CP function corresponds to PGW-C and the UP function corresponds to PGW-U, transmission between network functions is performed via the Sxb interface. In another embodiment where the CP function corresponds to SMF and the UP function corresponds to UPF, transmission between network functions is performed via the N4 interface. In other embodiments, different UP and CP functions may be utilized, and messages may be sent through different interfaces (such as Sxa and Sxc interfaces).

[0055] In step 1, the UP function is configured to manage and assign IP addresses to the UE, for example as described above.

[0056] In step 2, the CP function sends a request message (e.g., a PFCP session establishment request) to the UP function to request the UP function to assign an IP address to the UE associated with the session to be established. According to 3GPP TS 29.244 v 16.3.1, the request to assign an IP address can be indicated by Create PDR / PDI / UE IP Address / CHOOSE, where a CHOOSE value of 1 indicates that the CP function requires the UP function to assign a UE IP address for this PDN / PDU session.

[0057] In step 3, the UP function assigns a UE IP address and sends a response message (e.g., a PFCP session establishment response) to the CP function, including an indication of the assigned IP address. The assigned UE IP address may be associated with one or more PDRs. Furthermore, according to embodiments of this disclosure, the response message includes a new IE: UE IP address allocation information. This IE includes an indication of the usage level of the IP address range configured in the UP function. In the illustrated example, this includes an indication of the proportion (e.g., percentage) of the allocated IP address range (UE IP address allocation metric: 56%) and an indication of the absolute number of available (i.e., unassigned) IP addresses (number of UE IP addresses: 100K). Additionally, the IE includes a sequence number associated with the information element (UE IP address sequence number: 1), which allows the CP function to determine the current usage level in the UP function by utilizing the usage level with the latest (e.g., highest) sequence number rather than the previously indicated usage level. In some embodiments, this sequence number increments with each indication of the usage level (e.g., each transmission of the UE IP address allocation information IE); alternatively, the sequence number may increment each time the usage level changes. Table 1 below shows a list of information elements that can be included in the message sent in step 3. This list includes the new IE, i.e., UE IP address allocation information, which includes an indication of the usage level according to embodiments of this disclosure.

[0058] In step 4, the IP address range in the UP function is almost exhausted.

[0059] In step 5, for another new PDU / PDN session, the CP function sends a request message again (e.g., a PFCP session establishment request with the option to create a PDR / PDI / UE IP address / selection), which instructs the CP function to request the UP function to allocate a UE IP address for this PDN / PDU session.

[0060] In step 6, similar to step 3 above, the UP function reassigns the UE's IP address and sends a response message with an indication of the assigned IP address to the CP function (e.g., PFCP Session Establishment Response Created PDR / UE IP Address). Again, similar to step 3, this message includes a new IE, which includes an indication of the usage level of the IP address range. In this message, the sequence number has been incremented (i.e., UE IP address sequence number: 2), and the usage level indication indicates a high proportion of assigned addresses (UE IP address allocation metric: 96%) and a low number of available IP addresses (UE IP addresses: 0.5K).

[0061] Based on the indicated usage level, in step 7, the CP function adjusts the algorithm used to select the UP function to assign an IP address to the UE. For example, the algorithm can be adjusted so that the UP function is less likely to be selected, or selected less frequently. In one embodiment, the algorithm can be adjusted so that the UP function is not selected to assign an IP address to the UE.

[0062] In step 9, the CP function sends a message relating to the ongoing PDN / PDU session associated with the UP function. For example, this message may include a request to modify some aspect of the session, such as a PFCP session modification request.

[0063] In step 10, the UP function sends a response message (e.g., a PFCP session modification response) to the CP function in response to the message sent in step 9. Prior to step 9, in step 8, the usage of the IP address range in the UP function had returned to a lower value. For example, PDN / PDU sessions associated with some allocated IP addresses may have terminated. Therefore, the response message sent in step 10 includes an indication of a new, lower usage level for the IP address range. In this message, the sequence number is incremented again (i.e., UE IP address sequence number: 3), and the usage level indication shows a low proportion of allocated addresses (UE IP address allocation metric: 36%) and a high number of available IP addresses (UE IP addresses: 900K). Table 2 below shows a list of information elements that can be included in the message sent in step 10. This list includes a new IE, namely UE IP address allocation information, which includes an indication of the usage level according to embodiments of this disclosure.

[0064] Based on the indicated usage level, in step 11, the CP function readjusts the algorithm used to select the UP function to assign an IP address to the UE. For example, the algorithm can be adjusted so that the UP function is more likely to be selected, or selected more frequently. In one embodiment, the algorithm can be adjusted so that the CP function begins to select the UP function again to assign an IP address to the UE.

[0065] In step 12, the CP function selects the UP function to assign an IP address to the UE and sends a request message to the UP function accordingly (e.g., a PFCP session establishment request with the option to create a PDR / PDI / UE IP address / selection), similar to steps 2 and 5 above.

[0066] In step 13, the UP function allocates a UE IP address and sends a response message to the CP function with an indication of the allocated IP address (e.g., PFCP SessionEstablishment Response Created PDR / UE IP Address). The response message includes an indication of the current usage level of the IP address range (UE IP address sequence number: 4, UE IP address allocation metric: 38%, number of UE IP addresses: 800K).

[0067] In one embodiment, an indication of the usage level of the IP address range in the UP function is included in a response message (e.g., the response message sent in steps 3, 6, 10, and 13) in response to the usage level exceeding a threshold. For example, the threshold may relate to the proportion of allocated IP addresses and be set to a value relatively close to fully utilizing the IP address range (e.g., 80% or 90%). Alternatively, the threshold may relate to the number of available IP addresses and be set to a relatively low value (e.g., 1K). Therefore, if the response message does not include an indication of the usage level, the CP function can assume a low usage level and may choose to allocate IP addresses to the UE using the UP function.

[0068] Despite Figure 2 As not shown, but it is possible that the entire IP address range in the UP function is allocated, and therefore one of the request messages received in steps 2, 5, 9, and 12 may cause the allocation of an IP address to the UE to fail. In this case, the response messages sent in steps 3, 6, 10, and 13 may include an indication of IP address allocation failure, rather than an indication of an IP address allocated to the UE. According to embodiments of this disclosure, the response message may additionally include an indication that the cause of the failure is that the entire IP address range is allocated. This indication may be included within the cause IE, for example, as... Figure 12 As shown. The reason value indicates whether the request to assign an IP address to the UE was successful, and the reason behind the rejection if the request was rejected. Table 8 below shows the possible reason values ​​that can be included in such a response message. It can be seen that an additional reason value (given the unassigned value xx) is included to indicate that the request was rejected because all dynamic IP addresses were assigned.

[0069] Figure 3 This is a signaling diagram illustrating signaling according to other embodiments of this disclosure. This embodiment is related to... Figure 2The embodiments shown and described above are very similar, except that the indication of the usage level of the IP address range in the UP function is not listed in a dedicated IE, but rather in a sub-IE within another IE (e.g., the load control information IE). Table 3 below shows the load control information IE according to this embodiment. This IE includes a new sub-IE, namely UE IP address allocation information, which includes an indication of the usage level according to embodiments of this disclosure.

[0070] Figure 4 This is a signaling diagram illustrating signaling according to other embodiments of the present disclosure. In this embodiment, the indication of the usage level of the IP address range is sent autonomously by the UP function, i.e., without response to a message from the CP function. For example, the UP function may send such a message in response to the usage level exceeding or falling below a threshold.

[0071] Steps 1 to 4 are similar to those above. Figure 2 and Figure 3 Steps 1 through 4 differ in that the response message sent in step 3 does not include any indication of the level of IP address range usage as described above. The UP function is responsible for managing and allocating UE IP addresses for each PDN / PDU session.

[0072] In step 5, the UP function sends a message to the CP function including an indication of the usage level of the IP address range in the UP function. This message may be a PFCP node report request, or something similar. Figure 4 The PFCP associated update request is shown. As described above, the indication of the usage level can be included within a dedicated IE. In the example shown, this includes an indication of the proportion (e.g., percentage) of the allocated IP address range (UE IP address allocation metric: 96%) and an indication of the absolute number of available (i.e., unallocated) IP addresses (number of UE IP addresses: 0.5K). Furthermore, the IE includes a sequence number associated with the information element (UE IP address sequence number: 1), which allows the CP function to determine the current usage level in the UP function by utilizing the usage level with the latest (e.g., highest) sequence number rather than the previously indicated usage level. Table 4 below shows the IEs that can be included in the messages sent in step 5 (and also in step 9 below). This list includes new IEs, namely UE IP address allocation information, which include an indication of the usage level according to embodiments of this disclosure.

[0073] In one embodiment, a message is sent in step 5 in response to the usage level exceeding a threshold. For example, the threshold may be related to the proportion of allocated IP addresses and is set to a value relatively close to the full utilization range of IP addresses (e.g., 80% or 90%). Alternatively, the threshold may be related to the number of available IP addresses and is set to a relatively low value (e.g., 1K).

[0074] In step 6, the CP function sends a response message to the UP function, such as a PFCP node report response or a PFCP association update response as shown in the figure.

[0075] Steps 7 and 8 are similar to the combination above. Figure 2 and Figure 3 Steps 7 and 8 are described. Therefore, the CP function adjusts the algorithm used to select the UP function to assign an IP address to the UE. For example, the algorithm can be adjusted so that the UP function is less likely to be selected, or selected less frequently. In one embodiment, the algorithm can be adjusted so that the UP function is not selected to assign an IP address to the UE. At a later time, the usage level decreases in step 8.

[0076] In step 9, the UP function sends a message to the CP function (e.g., a PFCP node report request or a PFCP association update request). The message includes an indication of a new, lower usage level for the IP address range. In this message, the sequence number is incremented (i.e., UE IP address sequence number: 2), and the indication of the usage level indicates a low proportion of allocated addresses (UE IP address allocation metric: 56%) and a relatively high number of available IP addresses (UE IP addresses: 100K).

[0077] In one embodiment, a message is sent in step 9 in response to a usage level falling below a threshold. For example, the threshold could be related to the proportion of allocated IP addresses or the number of available IP addresses. The threshold could have the same value as the threshold described above in conjunction with step 5, or a different value (e.g., a lower value) such that messages are not sent at a higher frequency when the usage level reaches or approaches the threshold.

[0078] In step 10, the CP function sends a response message to the UP function (e.g., a PFCP node report response or a PFCP association update response).

[0079] Steps 11 to 13 are similar to the combination above. Figure 2 and Figure 3 The difference between steps 11 to 13 is that the response message sent in step 13 does not include an indication of the level of use of the IP address range in the UP function.

[0080] Figure 5 This is a signaling diagram illustrating signaling according to other embodiments of the present disclosure. In this embodiment, the indication of the usage level of an IP address range is sent by the UP function according to the subscription terms of the CP function. Similarly, in this example, the UP function may send an indication of the usage level in response to the usage level exceeding or falling below a threshold.

[0081] In step 1, the CP function sends a subscription request message (e.g., a PFCP association setting request) to the UP function, for the UP function to report the usage level of its IP address range. The subscription request message may include one or more conditions under which the usage level should be reported. For example, conditions may include one or more of the following: a threshold usage level at which the usage level should be reported; a threshold usage level at which the usage level should be stopped when it is below; and the frequency at which the usage level should be reported. In one embodiment, conditions may include multiple thresholds such that the UP function reports its usage level when the usage level exceeds a specific threshold. Table 5 below shows what can be included... Figure 5 The IEs sent in steps 7 and 11. This list includes new IEs, namely UE IP address allocation information, which includes a request for the UP function to report its usage level, and may also contain instructions on one or more of these conditions.

[0082] In step 2, the UP function sends a response or acknowledgement message (e.g., a PFCP association setting response) to the CP function. Afterwards, an indication of the usage level is sent by the UP function to the CP function under the conditions specified in the subscription. Steps 3 through 15 correspond to the above combinations. Figure 4 Steps 1 to 13 as described.

[0083] Table 6 below shows the items that can be included Figure 5 The IEs sent in steps 7 and 11. This list includes new IEs, namely UE IP address allocation information, which includes indications of usage levels according to embodiments of this disclosure. Figure 11 The structure of the Node Report Type IE listed in Table 6 is shown. It can be seen that bit 5 of the octet 5 includes a bit for UE IP Address Allocation Information (UIAAR), which is set (e.g., set to "1") to indicate the presence of a UE IP Address Allocation Information IE in the message. The messages sent in steps 7 and 11 (e.g., PFCP Node Report Requests) can be sent by the UP function via the Sxa, Sxb, Sxc, and N4 interfaces to report information not specific to the PFCP session to the CP function.

[0084] Figure 6 This is a flowchart illustrating a method implemented at the UP function according to an embodiment of the present disclosure. This flowchart may correspond in certain portions to... Figures 2 to 5The signaling executed by the UP function in any of the diagrams. For example, the UP function may correspond to UPF or PGW-U. The UP function is configured with IP address ranges for allocation to the UE. The IP address ranges configured in the UP function may include one or more UE IP address pools. Each of the UE IP address pools can be associated with a specific network instance configured in the UP entity. That is, each network instance of the UP function can be associated with one or more UE IP address pools.

[0085] At box 600, the UP function receives a message from the CP function. This message may include a request for the UP function to assign an IP address to the UE, for example, as part of a request to establish a PDU or PDN session for the UE. See, for example, [link to relevant documentation]. Figure 2 and Figure 3 Step 2. In these examples, the request message may include an indication of the network instance of the UP function, and may also include an identifier of the pool of UE IP addresses from which the UP function will allocate IP addresses. Alternatively, the message may include a subscription request for the UP function to report its usage level. See, for example, [link to relevant documentation]. Figure 5 Step 1.

[0086] Box 602 illustrates an alternative embodiment in which the UP function reports its usage level to the CP function, provided that the usage level exceeds a threshold. Therefore, in box 602, the UP function determines whether the usage level of its configured IP address range is higher than a threshold. For example, the threshold may be related to the proportion of allocated IP addresses and is set to a value relatively close to fully utilizing the IP address range (e.g., 80% or 90%). Alternatively, the threshold may be related to the number of available IP addresses and is set to a relatively low value (e.g., 1K). If the usage level does not exceed the threshold, the method ends and the UP function does not report its usage level to the CP function. For example, the UP function may not respond to the message received in step 600 (especially if the message is a subscription request), or it may respond without any indication of its usage level (especially if the message is a request for the UP function to allocate an IP address to the UE). If the usage level does not exceed the threshold, the method continues to step 604 and the UP function reports its usage level to the CP function. Alternatively, the UP function may not be configured in this manner and may proceed directly to step 604 after step 600.

[0087] In step 604, the UP function sends a message to the CP function including an indication of the usage level of the IP address range in the UP function. The indication of usage level may include an indication of the proportion of the currently allocated IP address range, such as a percentage. The indication of proportion may be implicit or explicit. For example, in the former case, the indication may be a proportion of the currently available IP address range. Since IP addresses can be either allocated or available, an indication of the proportion of the former is an implicit indication of the proportion of the latter, and vice versa. The indication of usage level may additionally or alternatively include the absolute number of available IP addresses within the range. Again, an indication of the absolute number may be implicit or explicit. For example, in the former case, the indication may include an indication of the total number of IP addresses (available and allocated) within the range and the number of allocated IP addresses. Therefore, the number of available IP addresses can be derived from these numbers by subtraction.

[0088] According to some embodiments of this disclosure, the message may include a sequence number associated with an indication of the usage level for an IP address range, which enables the CP function to determine the current usage level in the UP function by utilizing the usage level with the most recent (e.g., highest) sequence number rather than the previously indicated usage level. In some embodiments, the sequence number increments with each indication of the usage level (e.g., each transmission of UE IP address allocation information IE); alternatively, the sequence number may increment each time the usage level changes.

[0089] The message sent in step 604 may include a response message to a request from the CP function for assigning an IP address to the UE. An example of this embodiment is shown above. Figure 2 and Figure 3 As shown below. For example, an indication of usage level can be included in such a message in response to a usage level exceeding a threshold. In this way, network resources are not used to report usage levels unless and until the usage level reaches a value at which a request to assign an IP address to the UE might be rejected because all IP addresses have already been assigned. Alternatively, the message can be sent autonomously by the UP function, for example, in response to a subscription request from the CP function. In this case, the message can be sent, for example, in response to a usage level exceeding a threshold. An example of this embodiment is shown below. Figure 4 and Figure 5 As shown in the image.

[0090] This may include more than one indication of usage level (e.g., in the same type of IE) to indicate usage level for different UE IP address pools and / or different network instances.

[0091] According to some embodiments (where the message sent in step 604 includes a response to a request to assign an IP address to the UE, and the request fails because the IP address range in the UP function is fully allocated), the message may additionally include an indication that the failure to assign an IP address to the UE was caused by the exhaustion of the IP address range in the UP function. This indication may include a reason value corresponding to this meaning. See, for example, Table 8.

[0092] Figure 7 This is a flowchart illustrating a method implemented at a CP entity according to an embodiment of the present disclosure. This flowchart may correspond in certain portions to... Figures 2 to 5 Signaling executed by the UP function in any of the diagrams. For example, a CP entity can correspond to an SMF or PGW-C.

[0093] At box 700, the CP function sends one or more messages to one or more UP functions. For example, an UP function may correspond to a UPF or PGW-U. The UP function is configured with IP address ranges for assignment to the UE. The IP address ranges configured in the UP function may include one or more UE IP address pools. Each of the UE IP address pools can be associated with a specific network instance configured in the UP entity. That is, each network instance of the UP function can be associated with one or more UE IP address pools.

[0094] The message sent in box 700 may include a request for the UP function to allocate an IP address to the UE, for example, when establishing a PDU / PDN session for those UEs. See, for example, Figure 2 and Figure 3 Alternatively or additionally, the message may include a subscription request for the UP function to report its usage level. See, for example, [link to relevant documentation]. Figure 5 The subscription request message may include one or more conditions under which usage levels should be reported. For example, conditions may include one or more of the following: a threshold usage level at which usage levels should be reported; a threshold usage level at which usage levels should be stopped from being reported; and the frequency at which usage levels should be reported. In one embodiment, conditions may include multiple thresholds such that the UP function reports its usage level when the usage level exceeds a specific threshold.

[0095] At box 702, the CP function receives one or more messages from one or more UP functions. At least one of these messages includes an indication of the usage level of an IP address range in the corresponding UP function. The indication of usage level may include an indication of a proportion of the currently allocated IP address range, such as a percentage. The proportion indication may be implicit or explicit. For example, in the former case, the indication may be a proportion of the currently available IP address range. Since IP addresses may be allocated or available, an indication of a proportion of the former is an implicit indication of a proportion of the latter, and vice versa. The indication of usage level may additionally or alternatively include the absolute number of available IP addresses in the range. Again, an indication of an absolute number may be implicit or explicit. For example, in the former case, the indication may include an indication of the total number of IP addresses (available and allocated) in the range and the number of allocated IP addresses. Thus, the number of available IP addresses can be derived from these numbers by subtraction.

[0096] According to some embodiments of this disclosure, the message may include a sequence number associated with an indication of the usage level for an IP address range, which enables the CP function to determine the current usage level in the UP function by utilizing the usage level with the most recent (e.g., highest) sequence number rather than the previously indicated usage level. In some embodiments, the sequence number increments with each indication of the usage level (e.g., each transmission of UE IP address allocation information IE); alternatively, the sequence number may increment each time the usage level changes.

[0097] The message received in step 702 may include a response message to a request from the CP function for assigning an IP address to the UE. An example of this embodiment is shown above. Figure 2 and Figure 3 This is illustrated (for example, see step 3 in those figures). For instance, an indication of the usage level can be included in such a message in response to the usage level exceeding a threshold. In this way, network resources are not used to report the usage level unless and until the usage level reaches a value at which a request to assign an IP address to the UE might be rejected because all IP addresses have already been assigned. Alternatively, the message can be sent autonomously by the UP function. In this case, the message can be received, for example, in response to the usage level exceeding a threshold. An example of this embodiment is shown below. Figure 4 and Figure 5 As shown in the image.

[0098] More than one indication of usage level (e.g., in the same type of IE) may be included in the message received in step 702, such as including usage levels for different UE IP address pools and / or different network instances.

[0099] According to some embodiments (where the message received in step 702 includes a response to a request to assign an IP address to the UE, and the request fails due to the complete allocation of the IP address range in the UP function), the message may additionally include an indication that the failure to assign an IP address to the UE was caused by the exhaustion of the IP address range in the UP function. This indication may include a reason value corresponding to this meaning. See, for example, Table 8.

[0100] In step 704, the CP function selects an UP function to allocate an IP address to the UE based on or according to the indicated usage level received in step 702. For example, the CP function may adjust the algorithm used to select the UP function to allocate an IP address to the UE. The algorithm may be adjusted so that an UP function with a relatively high usage level is less likely to be selected, or selected less frequently, than an UP function with a relatively low usage level. In one embodiment, the algorithm may be adjusted so that the UP function is not selected to allocate an IP address to the UE. The UP function may be selected based on one or more additional parameters, such as the UP function's location relative to the CP function or the UE (UP functions closer to the CP function or the UE may be preferred over UP functions farther away); the UP function's current load; the UP function's capacity; and the UP function's static capacity. Those skilled in the art will recognize that these parameters can be combined in any suitable manner for selecting an UP function.

[0101] In step 706, the CP function sends a request message to the selected UP function for the UP function to assign an IP address to the UE.

[0102] Figure 8 This is a block diagram illustrating an apparatus suitable for practicing some embodiments of the present disclosure. For example, any of the UP and CP functions described above can be implemented by apparatus 800. As shown, apparatus 800 may include a processor 810, a memory 820 storing programs, and a communication interface 830 optionally for data communication with other external devices via wired and / or wireless communication.

[0103] The program includes program instructions that, when executed by processor 810, enable device 800 to operate according to embodiments of the present disclosure, as described above. That is, embodiments of the present disclosure can be implemented, at least in part, by computer software executable by processor 810, or by hardware, or by a combination of software and hardware. For example, program instructions can cause device 800 (particularly when implementing the UP function) to execute... Figure 6 The methods listed in, or Figures 2 to 5The signaling for the UP function is shown in any of the diagrams. In another example, program instructions can cause device 800 (especially when implementing the CP function) to execute... Figure 7 The methods listed in, or Figures 2 to 5 Signaling for the CP function shown in any of the diagrams.

[0104] Memory 820 may be any type of memory suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Processor 810 may be any type of processor suitable for the local technical environment and, as a non-limiting example, may include one or more general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures.

[0105] Figure 9 This is a block diagram illustrating a UP entity 900 according to an embodiment of the present disclosure. The UP entity 900 may be configured with IP address ranges for allocation to a UE. As shown, the UP entity 900 includes a sending module 902. The sending module 902 may be configured to send a message to a control plane core network function, the message including an indication of the usage level of the IP address range.

[0106] Figure 10 This is a block diagram illustrating a CP entity 1000 according to an embodiment of the present disclosure. As shown, the CP entity 1000 includes a receiving module 1002 and a selection module 1004. The receiving module 1002 can be configured to receive messages from one or more user plane core network functions configured with corresponding IP address ranges for allocation to a UE. The messages include an indication of the usage level of the IP address range. The selection module 1004 can be configured to select a user plane core network function to allocate an IP address to the UE based on the indicated usage level.

[0107] The above modules can be implemented through hardware, software, or a combination of both.

[0108] Generally, the various exemplary embodiments can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while others may be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device, but this disclosure is not limited thereto. Although various aspects of the exemplary embodiments of this disclosure may be shown and described as block diagrams, flowcharts, or using some other graphical representation, it is fully understood that such blocks, apparatuses, systems, techniques, or methods described herein may be implemented as non-limiting examples in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0109] Therefore, it should be understood that at least some aspects of the exemplary embodiments of this disclosure can be practiced in various components such as integrated circuit chips and modules. Therefore, it should be understood that the exemplary embodiments of this disclosure can be implemented in a device embodied as an integrated circuit, wherein the integrated circuit may include circuitry (and possible firmware) embodying at least one or more of a data processor, digital signal processor, baseband circuitry, and radio frequency circuitry configurable to operate according to the exemplary embodiments of this disclosure.

[0110] It should be understood that at least some aspects of the exemplary embodiments of this disclosure may be embodied in computer-executable instructions, which are executed by one or more computers or other devices, such as in one or more program modules. Typically, program modules include routines, programs, objects, components, data structures, etc., which, when executed by a processor in a computer or other device, perform a specific task or implement a specific abstract data type. The computer-executable instructions may be stored on a computer-readable medium, such as a hard disk, optical disk, removable storage medium, solid-state memory, RAM, etc. As those skilled in the art will understand, the functionality of program modules can be combined or distributed as needed in various embodiments. Furthermore, functionality may be wholly or partially embodied in firmware or hardware equivalents, such as integrated circuits, field-programmable gate arrays (FPGAs), etc.

[0111] References to "an embodiment," "embodiment," etc., in this disclosure indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of those skilled in the art to implement such a feature, structure, or characteristic in conjunction with other embodiments, whether explicitly described or not.

[0112] It should be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element may be referred to as a second element and similarly a second element may be referred to as a first element, without departing from the scope of this disclosure. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed terms.

[0113] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that, when used herein, the terms “comprises,” “comprising,” “has,” “having,” “includes,” and / or “including” designate the presence of stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof. The terms “connect,” “connects,” “connecting,” and / or “connected” as used herein cover direct and / or indirect connections between two elements. This disclosure includes any novel features or combinations of features disclosed herein or in any of their generalized forms. Any modifications or alterations to the exemplary embodiments described above will be apparent to those skilled in the art when read in conjunction with the accompanying drawings, in view of the foregoing description. However, any and all modifications shall still fall within the scope of the non-limiting and exemplary embodiments of this disclosure.

[0114] Table 1: Information Elements in the PFCP Session Establishment Response

[0115]

[0116]

[0117]

[0118] Table 2: Information Elements in PFCP Session Modification Response

[0119]

[0120]

[0121]

[0122] Table 3: Load control information in the PFCP session establishment response (IE)

[0123]

[0124] Table 4: Information Elements in PFCP Association Update Requests

[0125]

[0126]

[0127]

[0128] Table 5: Information Elements in PFCP Association Settings Request

[0129]

[0130]

[0131] Table 6: Information Elements in PFCP Node Report Requests

[0132]

[0133] Table 7: UE IP address allocation information in PFCP node report requests (IE)

[0134]

[0135] Table 8: Cause Values

[0136]

[0137]

[0138]

Claims

1. A method performed by a user plane core network function (900) for a wireless communication network, the user plane core network function (900) being configured with Internet Protocol (IP) address ranges for assigning to user equipment (UE), the method comprising: If the proportion of occupied IP addresses exceeds a threshold, a (604) message is sent to the control plane core network function (1000), the message including an indication of the usage level of the IP address range.

2. The method of claim 1, wherein the indication of the usage level of the IP address range includes an indication of the number of IP addresses within the range that can be allocated to the UE.

3. The method of claim 2, wherein the indication of the number of IP addresses that can be used to allocate to the UE within the range includes the absolute number of IP addresses that can be used to allocate to the UE within the range.

4. The method of claim 1, wherein the indication of the usage level of the IP address range includes an indication of the portion of the IP address range that has already been allocated to the UE.

5. The method of claim 4, wherein the indication of the portion of the IP address range that has been allocated to the UE includes the percentage of the IP address range that has been allocated to the UE.

6. The method according to any one of claims 1 to 5, wherein the message further includes a sequence number indicating the usage level of the IP address range, so that the control plane core network function (1000) can distinguish between the current usage level of the IP address range and the previous usage level of the IP address range.

7. The method according to any one of claims 1 to 5, wherein the message includes a Packet Forwarding Control Protocol (PFCP) Association Update Request message.

8. The method according to any one of claims 1 to 5, wherein the message is sent in response to a subscription request from the control plane core network function.

9. The method according to any one of claims 1 to 5, wherein the method further comprises: Obtain the usage level of the IP address range in the user plane core network function (900).

10. The method according to any one of claims 1 to 5, wherein the method further comprises: Receive (600) a request message from the control plane core network function (1000), wherein the message is sent in response to the request message from the control plane core network function (1000).

11. The method of claim 10, wherein the request message indicates that the IP address range uses the horizontal reporting feature supported by the control plane core network function (1000).

12. The method of claim 10, wherein the request message from the control plane core network function (1000) includes a request to assign an IP address to the UE, wherein the message indicates that the allocation of the IP address to the UE failed, and wherein the message further includes an indication that the allocation of the IP address to the UE failed because there was a lack of available IP addresses within the IP address range configured in the user plane core network function (900).

13. The method of claim 9, further comprising: When it is determined that the usage level of the IP address range has reached 100%, the PFCP session establishment request message is rejected or no longer responded to.

14. The method according to any one of claims 1 to 5, wherein the user plane core network function (900) includes a packet data network gateway user plane PGW-U or a user plane function UPF, and wherein the control plane core network function (1000) includes a packet data network gateway control plane PGW-C or a session management function SMF.

15. The method according to any one of claims 1-5, wherein the user plane core network function (900) is further configured with a network instance, and wherein the IP address range for allocation to the UE corresponds to a pool of UE IP addresses belonging to the network instance.

16. The method according to any one of claims 1-5, wherein an indication of the level of use of the IP address range is included within the information element IE.

17. The method of claim 16, wherein an indication of the usage level of the IP address range is included in the load control information IE.

18. The method according to any one of claims 1-5, wherein an indication of the usage level of the IP address range is included in a message sent to the control plane core network function (1000) in response to the usage level of the IP address range exceeding a threshold.

19. A method performed by a control plane core network function (1000) for a wireless communication network, the wireless communication network including a user plane core network function (900) configured with Internet Protocol (IP) address ranges for assigning to user equipment (UE), the method comprising: If the proportion of occupied IP addresses exceeds a threshold, a message (702) is received from the user plane core network function (900), the message including an indication of the usage level of the IP address range; and Based at least on the usage level, the user plane core network function is selected to assign IP addresses to the UE.

20. The method of claim 19, wherein the indication of the level of use of the IP address range includes an indication of the number of IP addresses within the range that can be allocated to the UE.

21. The method of claim 20, wherein the indication of the number of IP addresses that can be allocated to the UE within the range includes the absolute number of IP addresses that can be allocated to the UE within the range.

22. The method of claim 19, wherein the indication of the usage level of the IP address range includes an indication of the portion of the IP address range that has already been allocated to the UE.

23. The method of claim 22, wherein the indication of the portion of the IP address range that has been allocated to the UE includes the percentage of the IP address range that has been allocated to the UE.

24. The method according to any one of claims 19 to 23, wherein the message further includes a sequence number indicating the usage level of the IP address range so that the control plane core network function (1000) can distinguish between the current usage level of the IP address range and the previous usage level of the IP address range.

25. The method of claim 24, wherein the user plane core network function is selected based on the current level of usage.

26. The method according to any one of claims 19 to 23, wherein the message includes a Packet Forwarding Control Protocol (PFCP) Association Update Request message.

27. The method of any one of claims 19 to 23, further comprising sending a subscription request message to the user plane core network function (900), wherein the message is received in response to the subscription request message.

28. The method of claim 27, wherein the message includes a PFCP node report request.

29. The method according to any one of claims 19 to 23, further comprising sending a request message to the user plane core network function (900) and receiving the message in response to the request message sent from the control plane core network function (1000).

30. The method of claim 29, wherein the request message includes a PFCP session establishment request message or a PFCP session modification request message.

31. The method of claim 29, wherein the request message includes a request to assign an IP address to the UE, wherein the message indicates that the assignment of the IP address to the UE failed, and wherein the message further includes an indication that the assignment of the IP address to the UE failed because there was a lack of available IP addresses within the IP address range configured in the user plane core network function (900).

32. The method according to any one of claims 19 to 23, wherein the first user plane core network function (900) has a first indicated usage level, wherein the second user plane core network function (900) has a second indicated usage level higher than the first indicated usage level, and wherein the control plane core network function (1000) selects the first user plane core network function (900) to allocate IP addresses at a higher frequency or with a higher probability than the second user plane core network function (900).

33. The method according to any one of claims 19 to 23, wherein assigning an IP address to the UE based on the indicated use level for selecting the user plane core network function further comprises: When the IP address range of the user plane core network function (900) has reached 100% utilization, the user plane core network function (900) is not selected.

34. The method according to any one of claims 19 to 23, wherein the user plane core network function (900) includes a packet data network gateway user plane PGW-U or a user plane function UPF, and wherein the control plane core network function (1000) includes a packet data network gateway control plane PGW-C or a session management function SMF.

35. The method according to any one of claims 19 to 23, wherein the user plane core network function (900) is further configured with a network instance, and wherein the IP address range for allocation to the UE corresponds to a pool of UE IP addresses belonging to the network instance.

36. The method according to any one of claims 19 to 23, wherein an indication of the level of use of the IP address range is included within the information element IE.

37. The method of claim 36, wherein an indication of the usage level of the IP address range is included in the load control information IE.

38. A network entity (800, 900) implementing a user plane core network function (900) for a wireless communication network, the user plane core network function (900) being configured with an Internet Protocol (IP) address range for assigning to a user equipment (UE), the network entity (800, 900) comprising: At least one processor (810); as well as At least one memory (820) contains instructions executable by the at least one processor (810), thereby enabling the network entity (800) to operate in the following manner: If the proportion of occupied IP addresses exceeds a threshold, a message is sent to the control plane core network function (1000), the message including an indication of the usage level of the IP address range.

39. The network entity (800) according to claim 38, wherein the network entity (800) is operable to perform the method according to any one of claims 2 to 18.

40. A network entity (800, 1000) implementing a control plane core network function (1000) for a wireless communication network, the wireless communication network including a user plane core network function (900) configured with an Internet Protocol (IP) address range for assigning to a user equipment (UE), the network entity (800, 1000) comprising: At least one processor (810); as well as At least one memory (820) contains instructions executable by the at least one processor (810), thereby enabling the network entity (800) to operate in the following manner: If the proportion of occupied IP addresses exceeds a threshold, a message is received from the user plane core network function (900), the message including an indication of the usage level of the IP address range; and Based at least on the usage level, the user plane core network function is selected to assign IP addresses to the UE.

41. The network entity (800) according to claim 40, wherein the network entity (800) is operable to perform the method according to any one of claims 20 to 37.

42. A computer-readable storage medium (820) comprising instructions that, when executed by at least one processor (810), cause the at least one processor (810) to perform the method according to any one of claims 1 to 37.

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