TELECOMMUNICATIONS SYSTEMS

TECHNICAL FIELD

[0001] The present invention generally relates to communication networks and, more particularly, to mechanisms and techniques for charging systems.

BACKGROUND

[0002] Over time the number of products and services provided to users of telecommunication products has grown significantly. For example, in the early years of wireless communication, devices could be used for conversations and later also had the ability to send and receive text messages. Over time, technology advanced and wireless phones of varying capabilities were introduced which had access to various services provided by network operators, e.g., data services, such as streaming video or music service. More recently there are numerous devices, e.g., so called “smart” phones and tablets, which can access communication networks in which the operators of the networks, and other parties, provide many different types of services, applications, etc. Accordingly, there need to be methods and systems for efficiently charging for services, particularly, as service offerings exist in a dynamic environment with expectations of increased volume and new types of services becoming available. Additionally, there are now multiple different radio access technologies (RATs) as well as various generations of the various RATS which further adds to this complexity.

[0003] Regarding the charging for services in a 4G environment, the standards specify an Sy reference point between the Policy and Charging Rules Function (PCRF) and the Online Charging System (OCS). The Sy reference point enables transfer of policy counter status information relating to subscriber spending from the OCS to the PCRF. The PCRF node would then use this information to decide on the Quality of Service (QoS) to be provided for a subscriber session by the respective Policy and Charging Enforcement Function (PCEF) node. The RFC 3588, the Diameter Credit Card Application) and the 3 ^rd Generation Partnership Project (3GPP) 29.219 provides a session-based communication mechanism between the PCRF and the OCS for 4G. [0004] When a subscriber initiates a data session via the PCEF node, the Gx interface will interact with the PCRF to request the appropriate QoS and other policies for the respective subscriber session. The PCRF node will further communicate over the Sy session with the OCS node to determine policy counters for the session. Policy counters related information is only available on the OCS node, therefore the Sy interface is used for policy counter based QoS allocation.

[0005] As operator networks switch over to 5G, a different architecture is used with respect to a policy and control framework, a reference architecture 100 associated with the policy and charging control framework for a 5G system is now described below with respect to Figure 1. In Figure 1 , the reference architecture 100 includes a Policy and Charging Function (PCF) 102, a Charging Function (CHF) 104, an Access and Mobility Management Function 1 (AMF1) 106, an AMF2 108, a User Equipment (UE) 110 and a Network Slice Selection Function (NSSF) 112.

[0006] As shown in Figure 1 , there is also an N28 interface (or reference point) 114 between the PCF 102 and the CHF 104, which is defined for interactions between the PCF 102 and the CHF 104. The N28 interface 114 performs functions in 5G which are similar to the above described Sy interface for 4G, these functions being modified to work in a 5G architecture and, therefore, including additional features. For example, the N28 interface 114 can also be associated with an Nchf_spending limit support service which enables the PCF 102 to access policy counter status information relating to subscriber spending from the CHF 104. Further, the Nchf_spending limit can also support the following features: (1) request for reporting of policy counter status information from the PCF 102 to the CHF 104 and subscribe or unsubscribe from spending limit reports, e.g., notifications of policy counter status changes; (2) report of policy counter status information upon a PCF request from the CHF 104 to the PCF 102; (3) notification of spending limit reports from the CHF 104 to the PCF 102; and (4) cancellation of spending limit reporting from the PCF 102 to the CHF 104. Further, as the N28 interface 114 resides between the PCF 102 and the CHF 104, in a Home Public Land Mobile Network (HPLMN), roaming with home routed and non-roaming scenarios are supported in the same manner.

[0007] In the 5G architecture, the N28 interface includes such features as spending limits and the bandwidth can be throttled by the PCRF/PCF once a limit of data is exhausted by a subscriber, e.g., 1 gigabyte (Gb) for 2 Megabits per second (Mbps) and later 1 Mbps. The OCS manages the bucket of the total data consumed by the subscriber and provides the update to the PCF 102 for reducing and/or changing the bandwidth post exhaustion of the data limit.

[0008] Another driver associated with the 5G charging system architecture and associated processes is the ability of 5G to enable many business use cases across Business to Consumer (B2C), Business to Business (B2B), Business to Business to Consumer (B2B2C), etc., domains and therefore, in some cases, there will be additional focus on enterprise customers like a software defined wide area network (SD WAN) enterprise requiring dedicated network slice(s) in a Public Land Mobile Network (PLMN) and across the globe, e.g., dedicated network slices across the globe for healthcare managed by a United Nations (UN) organization. In this context, 5G network slices can, for example, be considered to be a type of network architecture that enables the multiplexing of virtualized and independent logical networks on the same physical network infrastructure. Each network slice is an isolated end-to-end network tailored to fulfill diverse requirements requested by a particular application. The use of network slices in 5G further complicates charging for services relative to 4G systems.

[0009] For example, 5G Internet of Things (loT) use cases are mostly expected to be Machine to Business (M2B) loT businesses where companies and governments will have several types of devices that will monitor, trigger or perform several activities that could not be performed in 4G networks due to the needs of latency and/or throughput. These network requirements will compose a network slice that will enable these use cases. Described below are two use cases with their specific requirements. [0010] For a first use case, consider autonomous vehicle control which can include the following network requirements: a latency of 5 ms; an availability of 99.999% and a reliability of 99.999%. For the second use case, consider a so-called “Smart City”, which can have a network requirement of: user throughput downlink (DL) of 300 Mbps and an uplink (UL) of 60 Mpbs; a traffic Density of 700 Gbps/km ² ; and a connection density of 200,000 devices/km ² . [0011] Each of these use cases will have its requirements in specific network slices being created by Communication Service Providers (CSPs) and these use cases could be charged in accordance with the business needs and usage of the network from the CSPs. The higher the average revenue per user (ARPU) generated by the enterprise, whether in one PLMN or across multiple PLMNs, will lead to different service level agreements/key performance indicators (SLAs/KPIs). Hence support via dedicated network slices in 5G will provide a more controlled and independent way for the implementation of services as compared to legacy networks, assuming the legacy networks can even provide such options. In the case of Mobile Virtual Network Operators (MVNOs), the CSPs can provide the handling of network slice management via a management and orchestration application programming interface (MANO API) to the respective MVNOs.

[0012] In 4G, typically, there is one network for enhanced Mobile Broadband (eMBB) use cases and as 4G has no concept of any form of implementation of a network slice, the bandwidth changes can only be applied via the PCF 102 for throttling at a Packet Gateway (PGW). However, this feature of 4G networks can lead to congestion on different network functions, e.g., Radio Access Network (RAN) transportation/backhaul and core network issues (Pgw, UPw). Additionally, a same level of segregation is not possible at the network function level in 4G as compared to the network slice level in 5G.

[0013] Network congestion is a harsh and practical reality for CSPs in 4G due to different reasons, e.g., increased demand on special days, time of the day, special events, etc. Further, congestion scenarios can affect the users’ experience and lead to unnecessary churn, which can be detrimental to a CSP’s revenue. An example of this can be seen in a 4G network where a high revenue customer tries to latch up in network and, due to radio congestion, the user is not able to make an outgoing call. So, the respective user needs to wait for the congestion to end or try multiple times to get a radio slot for the outgoing call.

[0014] Additionally, there is no mechanism currently provided in the 3GPP specifications where the recommendation of movement of subscribers across network slices are triggered by a CHF/Business Support System (BSS) aspect.

[0015] Thus, there is a need to provide methods and systems that overcome the above-described drawbacks associated with the charging schemes described in 4G for enabling charging in 5G telecommunication networks.

SUMMARY

[0016] Embodiments allow for moving a user session from a first network slice to a second network slice. This allows, for example, network slice segregation to provide better control for a Communication Service Provider (CSP) to prioritize a high priority customer in one network slice using similar business use cases. This concept of moving user sessions across network slices can be used to increase revenue for a telecommunication operator.

[0017] According to an embodiment, there is a method for moving a user session from a first network slice to a second network slice. The method comprising: receiving charging information associated with moving the user session from the first network slice to the second network slice; determining, based at least in part on the received charging information, to move the user session from the first network slice to the second network slice; and initiating a change of the user session from the first network slice to the second network slice when the determination is made to move the user session.

[0018] According to an embodiment, there is a system for moving a user session from a first network slice to a second network slice. The system including a communication interface configured to receive charging information associated with moving the user session from the first network slice to the second network slice; a processor configured to determine, based at least in part on the received charging information, to move the user session from the first network slice to the second network slice; and the processor configured to initiate a change of the user session from the first network slice to the second network slice when the determination is made to move the user session, wherein the communication interface and the processor are located on at least one communication node.

[0019] According to an embodiment, there is a computer-readable storage medium containing a computer-readable code that when read by a processor causes the processor to perform a method moving a user session from a first network slice to a second network slice. The method including receiving charging information associated with moving the user session from the first network slice to the second network slice; determining, based at least in part on the received charging information, to move the user session from the first network slice to the second network slice; and initiating a change of the user session from the first network slice to the second network slice when the determination is made to move the user session.

[0020] According to an embodiment, there is an apparatus adapted to receive charging information associated with moving a user session from a first network slice to a second network slice; to determine, based at least in part on the received charging information, to move the user session from the first network slice to the second network slice; and to initiate a change of the user session from the first network slice to the second network slice when the determination is made to move the user session.

[0021] According to an embodiment, there is an apparatus including a first module configured to receive charging information associated with moving the user session from the first network slice to the second network slice; a second module configured to determine, based at least in part on the received charging information, to move the user session from the first network slice to the second network slice; and a third module configured to initiate a change of the user session from the first network slice to the second network slice when the determination is made to move the user session.

BRIEF DESCRIPTION OF THE DRAWINGS [0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments. In the drawings:

[0024] Figure 1 illustrates a portion of a 5G architecture associated with a Policy Control Function (PCF);

[0025] Figure 2 shows Charging Function (CHF) triggering network slice movement according to an embodiment;

[0026] Figure 3 shows signaling diagram for CHF triggered network slice movement according to an embodiment;

[0027] Figure 4 shows a flowchart of a PCF triggered network slice movement according to an embodiment;

[0028] Figure 5 depicts a signaling diagram of post recharge movement of a user equipment (UE) from a lower priority network slice to a higher priority network slice; [0029] Figure 6 shows a method flow diagram for moving a user session from a first network slice to a second network slice according to an embodiment;

[0030] Figure 7 depicts a communication node according to an embodiment; and

[0031] Figure 8 depicts an electronic storage medium on which computer program embodiments can be stored. DETAILED DESCRIPTION

[0032] The following description of the embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The embodiments to be discussed next are not limited to the configurations described below, but may be extended to other arrangements as discussed later.

[0033] Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily all referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

[0034] As described in the Background section, there are opportunities to further segregate customer experience associated with using the charging schemes described in 4G for charging in 5G telecommunication networks. Embodiments described herein support allowing Communication Service Providers (CSPs) to easily segregate the experience across subscribers which are attached to different logical network slices to provide different customer experiences. For example, a change in revenue limits and/or revenue thresholds can be a trigger for a telecommunications network to deprioritize the subscriber(s) to a low priority network slice and ensure that a superior experience occurs for high revenue customer(s) by keeping the high revenue subscriber(s) on a high priority network slice.

[0035] Prior to describing the various embodiments in detail, a brief description of some concepts and structures associated with 5G are first presented. 5G introduces the concept and functionality of network slices which can be used across different business use cases as well as allowing the possibility for subscribers to move across network slices with similar characteristics including changes possible for a new session as well as ongoing sessions. The N28 interface used in a 5G architecture has some similarities to the Sy interface used in 4G as a spending limit counter to degrade the Quality of Service (QoS) for respective users once their respective data limit is reached. The network slice concept theoretically segregates the network into different sub logical networks with respective characteristics. Network slices can be treated as separate and logically dedicated combinations of Radio Access Network (RAN)/transport/packet core. A “network slice”, as used herein, can be described as a logical network used in a one or more 5G networks, wherein the network slice appears to a user as an independent network.

[0036] Embodiments described herein allow for situations where a subscriber is recommended to be moved from a first network slice to a second network slice based on a trigger from a Charging Function (CHF), where the first network slice is of a higher priority than the second network slice. This is illustrated in Figure 2 which shows a message 200 recommending network slice movement being sent from the CHF 202 to the Network Slice Selection Function (NSSF) 204. Additionally, two other scenarios associated with moving a subscriber from one network slice to another network slice according to embodiments include: (1) a Policy and Charging Function (PCF) triggered movement of the subscriber, or user equipment (UE), from a first network slice to a second network, where the first network slice is of a higher priority than the second network slice; and (2) during a post recharge action, movement of the subscriber or user equipment (UE), from a first network slice to a second network, where the first network slice is of a lower priority than the second network slice. These embodiments are described in more detail below.

[0037] Additionally, embodiments can provide the flexibility to a CSP/Operator to segregate the services provided to high priority customers as compared to lower priority customers in real-time based on 5G network slice movement concepts. These slice movements can consider aspects over and above PCF base spending limit(s), i.e., throttling, as 5G can include other consideration parameters, such as, latency, speed, and data requirements, which are different from 4Gand which can be addressed via 5G network slicing concepts.

[0038] According to an embodiment, Figure 3 shows signaling associated with a CHF triggered network slice movement from a higher priority network slice to a lower priority network slice. The signaling diagram 300 includes a UE 302, a NSSF 204, an Access and Mobility Management Function (AMF)1 304, and AMF2 306, a PCF 308 and the CHF 202. Initially, the UE establishes a Packet Data Unit (PDU) session, per TS 23.502, and initiates the session as shown in step 310. Step 310 includes establishing the PDU session with a first network slice (NS1), which in this case is a high priority network slice. The PCF 308 will then send a request 312 to the NChf on the N28 interface to determine whether the spending limit associated with the subscriber of the UE 302 is exhausted or still has a positive balance. This balance can be money, data, and the like. At some point in time, the CHF 202 determines that the balance is exhausted as shown in step 314. The CHF 202 then requests, in message 316, the session originating AMF network function, in this case AMF1 304, to change the currently used network slice (NS1) to a lower priority network slice (NS2).

[0039] The AMF1 304 then sends a message 318 which includes a new parameter, Subscriberstatusind, to the NSSF 204 for the NSSF 204 to consider when performing future network slice selection for the UE 302. Subscriberstatusind is a parameter which could be introduced in 5G and which is associated with the Nnssf interface to allow the NSSF 204 to identify that a currently used network slice should be updated and to return such information back to the originating AMF. The Subscriberstatusind parameter can include a numeric parameter such that each number will have its own identification and which can further be expanded in the future to include additional information. For an example, consider the Subscriberstatusind parameter to include values as shown below:

1 - High

2 - Medium

3 - Low

4 - Enterprise_high

5 - Consumerjow

6+ - reserved for future use/to be defined based on compelling 5G use cases It is to be understood that this example of priorities is only an example and can be modified as needed. For example, priorities and numbers can also be used to reflect such information as 911/emergency information and/or revenue information.

[0040] According to an embodiment, when the NSSF 204 receives the information included in the Subscriberstatusind, the NSSF 204 can update/modify its information associated with its repository of network slices. Thus, in this example, the NSSF 204 updates the network slice information associated with UE 302. The NSSF 204 then transmits a message 320 to AMF1 304 requesting AMF1 304 to re-initiate the registration with UE 302 so that UE 302 can be moved to a different network slice than the network slice to which it is currently connected. AMF1 304 then updates the network slice selection information and forwards that information as shown in message 322 to the appropriate AMF, in this case AMF2 306 which will be responsible for the new network slice, for handover of the UE 302. AMF2 306 then re-initiates the registration procedure as shown in step 324 to then include the normal registration request from the UE 302.

[0041] The UE 302 then requests the new network slice (NS2) attachment from AMF2 306 as shown in message 326. According to an embodiment, upon registration request, the AMF may decide on its own to which network slice the UE 302’s session should be handed over, e.g., based on inputs from the NSSF 204, or the AMF may re check with the NSSF 204 for network slice information. In this example, it can be seen that AMF2 306 re-checks with the NSSF 204 for network slice information as shown by message 328. The NSSF 204 then sends the network slice information for NS2, as shown in message 330, to AMF2 306. The AMF2306 continues with session creation using NS2 and the UE establishes the new PDU session with NS2, which is a lower priority network slice than previously used NS1, and the session is initiated on the new network slice (NS2) as seen in step 332.

[0042] According to another embodiment, Figure 4 shows the signaling associated with PCF triggered network slice movement from a higher priority network slice to a lower priority network slice. The signaling diagram 400 includes a UE 302, a NSSF 204, an AMF1 304, and AMF2 306, the PCF 308 and the CHF 202. Initially, the UE establishes a Packet Data Unit (PDU) session, per TS 23.502 and initiates the session as shown in step 402. Step 402 includes establishing the PDU session with a first network slice (NS1), which in this case is a high priority network slice. The PCF 308 will then send a request 404 to the NChf on the N28 interface to determine whether the spending limit associated with the subscriber of the UE 302 is exhausted or still has a positive balance. This balance can be money, data, and the like. At some point in time, the CHF 202 determines that the balance is exhausted as shown in step 314. The CHF 202 then informs the PCF 308 of this balance exhausted condition as shown in message 408. The PCF 308 then requests, in message 410, that the session originating AMF network function, in this case AMF1 304, to change the currently used network slice (NS1) to a lower priority network slice (NS2).

[0043] The AMF1 304 then sends a message 412 which includes a parameter, Subscriberstatusind, to the NSSF 204 for the NSSF 204 to consider when performing future network slice selection for the UE 302. As described above,

Subscriberstatusind is a parameter which can be introduced in 5G and which is associated with the Nnssf interface that will allow the NSSF 204 to identify that a currently used network slice should be updated and to return such information back to the originating AMF.

[0044] According to an embodiment, when the NSSF 204 receives the information included in the Subscriberstatusind, the NSSF 204 can update/modify its information associated with its repository of network slices. Thus, in this example, the NSSF 204 updates the network slice information associated with UE 302. The NSSF 204 then transmits a message 414 to AMF1 304 requesting AMF1 304 to re-initiate the registration with UE 302 so that UE 302 can be moved to a different network slice than the network slice to which it is currently connected. AMF1 304 then updates the network slice selection information and forwards that information as shown in message 416 to the appropriate AMF, in this case AMF2 306 which will be responsible for the new network slice, for handover of the UE 302. AMF2 306 then re-initiates the registration procedure as shown in step 418 to then include the normal registration request from the UE 302.

[0045] The UE 302 then requests the new network slice (NS2) attachment from AMF2 306 as shown in message 420. According to an embodiment, on registration request, the AMF may decide to which network slice to handover the UE’s session on its own based on inputs from the NSSF 204, or the AMF may re-check with the NSSF 204 for network slice information. In this example, it can be seen that AMF2 306 re-checks with the NSSF 204 for network slice information as shown by message 422. The NSSF 204 then sends the network slice information for NS2, as shown in message 424, to AMF2 306. The AMF2 306 continues with session creation using NS2 and the UE establishes the new PDU session with NS2, which is a lower priority network slice than previously used NS1 , and the session is initiated on the new network slice (NS2) as seen in step 420. [0046] According to another embodiment, Figure 5 shows the signaling associated with moving from a lower priority network slice to a higher priority network slice based on a change of subscriber/account condition, e.g., a recharging of a monetary or data balance associated with a session. The signaling diagram 500 includes the UE 302, the NSSF 204, the AMF1 304, and AMF2 306, the PCF 308 and the CHF 202. Initially, the UE establishes a PDU session, per TS 23.502 and initiates the session as shown in step 502. Step 502 includes establishing the PDU session with a NS2, which in this case is a low priority network slice. In step 504, it is determined by the CHF 202 that there has been a balance recharge in which the prepaid connection amount now exceeds a limit for premium service and as such is indicative of using a higher priority NS.

[0047] The CHF transmits message 506 to AMF2 306 requesting AMF2 306 to change the network slice to a high priority network slice. AMF2 306 then sends information with the parameter, Subscriberstatusind, to the NSSF 204 in message 508 for the NSSF 204 to consider when performing future network slice selection for the UE 302. As described above, Subscriberstatusind is a parameter which can be included in 5G and which is associated with the Nnssf interface that will allow the NSSF 204 to identify that a currently used network slice should be updated and to return such information back to the originating AMF.

[0048] Thus, in this example, the NSSF 204 updates the network slice information associated with UE 302. The NSSF 204 then transmits a message 510 to AMF2 306 requesting AMF2 306 to re-initiate the registration with UE 302 so that UE 302 can be moved to a different network slice than the network slice to which it is currently connected. AMF2 306 then updates the network slice selection information and forwards that information as shown in message 512 to the appropriate AMF, in this case AMF1 304 which will be responsible for the new network slice, for handover of the UE 302. AMF1 304 then re-initiates the registration procedure as shown in step 514 to then include the normal registration request from the UE 302.

[0049] The UE 302 then requests the new network slice NS1 attachment from AMF1 304 as shown in message 516. According to an embodiment, upon registration request, the AMF may decide to which network slice the UE’s session should be handed over on its own based on inputs from the NSSF 204, or the AMF may re-check with the NSSF 204 for network slice information. In this example, it can be seen that AMF1 304 re checks with the NSSF 204 for network slice information as shown by message 518. The NSSF 204 then sends the network slice information for NS1, as shown in message 520, to AMF1 304. The AMF1 304 continues with session creation using NS1 and the UE 302 establishes the new PDU session with NS1 , which is a higher priority network slice than previously used NS2, and the session is initiated on the new network slice NS1 as seen in step 522.

[0050] According to an embodiment, there is a method 600 for moving a user session from a first network slice to a second network slice as shown in Figure 6. The method includes: in step 602, receiving charging information associated with moving the user session from the first network slice to the second network slice; in step 604, determining, based at least in part on the received charging information, to move the user session from the first network slice to the second network slice; and in step 606, initiating a change of the user session from the first network slice to the second network slice when the determination is made to move the user session [0051] Embodiments described above can be implemented in one or more nodes (or servers). An example of a communication node 700 is shown in Figure 7. The communication node 700 (or other network node) includes a processor 702 for executing instructions and performing the functions described herein, e.g., the functions performed by the nodes/equipment shown in Figures 2-6. The communication node 700 also includes a primary memory 704, e.g., random access memory (RAM) memory, a secondary memory 706 which can be a non-volatile memory, and an interface 708 for communicating with other portions of a network or among various nodes/servers in support of charging.

[0052] Processor 702 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other communication node 700 components, such as memory 704 and/or 706, node 700 functionality in support of the various embodiments described herein. For example, processor 702 may execute instructions stored in memory 704 and/or 706.

[0053] Primary memory 704 and secondary memory 706 may comprise any form of volatile or non-volatile computer readable memory including, without limitation, persistent storage, solid state memory, remotely mounted memory, magnetic media, optical media, RAM, read-only memory (ROM), removable media, or any other suitable local or remote memory component. Primary memory 704 and secondary memory 706 may store any suitable instructions, data or information, including software and encoded logic, utilized by node 700. Primary memory 704 and secondary memory 706 may be used to store any calculations made by processor 702 and/or any data received via interface 708.

[0054] Communication node 700 also includes communication interface 708 which may be used in the wired or wireless communication of signaling and/or data. For example, interface 708 may perform any formatting, coding, or translating that may be needed to allow communication node 700 to send and receive data over a wired connection. Interface 708 may also include a radio transmitter and/or receiver that may be coupled to or a part of the antenna. The radio may receive digital data that is to be sent out to other network nodes or wireless devices via a wireless connection. The radio may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters. The radio signal may then be transmitted via an antenna to the appropriate recipient.

[0055] Embodiments provide various advantages or improvements for moving a user session from a first network slice to a second network slice. For example, advantages can include the following: the CHF 202 can provide additional information related to the revenue aspect associated with network slice selection function directly to an NSSF 204 to take a final decision rather than communicating to other network functions, e.g., the PCF 308, for action; and Network Slice Selection Assistance Information (NSSA)I (to include a list of Single (S)-NSSAI and alternative S-NSSAI) information is not scattered across different network functions in 5G architecture and NSSFs can have a 360 degree view of all of the alternative options and exercise actions accordingly. Further, NSSFs can further decide whether to move the subscribers/users from one network slice to another network slice depending upon various other network level factors, which are only available to the NSSF 204, e.g., network slice load factor and/or service experience received from a NWDAF.

[0056] According to embodiments, advantages can also include that network slice segregation provides better control for CSP to prioritize the high priority customer in one network slice using similar business use cases, there can also be a better control and understanding on Operating Expenses/ Capital Expenditures (OPEX/CAPEX) and respective revenue earned for high priority customers at the network slice level. Also, embodiments allow for service providers to provide service to all consumer with const benefits that justify the investments to be done in the network. There can be less churn from high average revenue per user (ARPU) subscribers as embodiments can allow for a higher user experience as compared to others while continuing to provide subscribers with a low ARPU with a fair user experience.

[0057] Additionally, the NSSAI does not need to change, i.e., reduces/removes confusion why a list of the valid S-NSSAIs assigned to each subscriber/UE has changed One will not need to know which S-NSSAI is an alternative to the other S-NSSAIs outside of the NSSF 204, and the NSSF 204 can decide to leave the user on a so-called “better” NSSAI, e.g., an NSSAI with more unused capacity.

[0058] Various embodiments described herein refer in some fashion to nodes, e.g., nodes which support functions associated with charging. In some embodiments the non limiting communication node (also interchangeably called a node or telecommunication node) is more commonly used and it refers to any type of network node which directly or indirectly communicates with a user equipment (UE), a node in one or more operator networks, and a core network. [0059] The disclosed embodiments provide methods and devices for moving a user session from a first network slice to a second network slice. It should be understood that this description is not intended to limit the invention. On the contrary, the embodiments are intended to cover alternatives, modifications and equivalents, which are included in the spirit and scope of the invention. Further, in the detailed description of the embodiments, numerous specific details are set forth in order to provide a comprehensive understanding of the claimed invention. However, one skilled in the art would understand that various embodiments may be practiced without such specific details.

[0060] As also will be appreciated by one skilled in the art, the embodiments may take the form of an entirely hardware embodiment or an embodiment combining hardware and software aspects. Further, the embodiments, e.g., the configurations and other logic associated with the charging process to include embodiments described herein, such as, the methods associated with Figure 6, may take the form of a computer program product stored on a computer-readable storage medium having computer-readable instructions embodied in the medium. For example, Figure 8 depicts an electronic storage medium 800 on which computer program embodiments can be stored. Any suitable computer- readable medium may be utilized, including hard disks, CD-ROMs, digital versatile disc (DVD), optical storage devices, or magnetic storage devices such as floppy disk or magnetic tape. Other non-limiting examples of computer-readable media include flash- type memories or other known memories.

[0061] Although the features and elements of the present embodiments are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the embodiments or in various combinations with or without other features and elements disclosed herein. The methods or flowcharts provided in the present application may be implemented in a computer program, software or firmware tangibly embodied in a computer-readable storage medium for execution by a specifically programmed computer or processor.