Patent Publication Number: US-2022232365-A1

Title: Systems and methods for enabling efficient establishment of policy control associations

Description:
BACKGROUND INFORMATION 
     This patent application is a continuation of U.S. patent application Ser. No. 16/925,954 filed on Jul. 10, 2020, titled “SYSTEMS AND METHODS FOR ENABLING EFFICIENT ESTABLISHMENT OF POLICY CONTROL ASSOCIATIONS,” the disclosure of which is hereby incorporated by reference herein in its entirety. 
     Wireless communication service providers continue to develop and expand available services and their delivery networks. An enhanced core network deployment enables separation of access management functionality from session management functionality. That is, user equipment (UE) access and mobility policy control function (AM PCF), discrete packet data unit (PDU) session management PCF (SM PCF), and UE access selection and PDU session-related PCF (UE PCF), may be handled independently. Facilitating efficient exchanging of AM policy data, UE policy data, and SM policy data within the core network, poses various challenges. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an environment according to an implementation described herein; 
         FIG. 2  is a diagram illustrating exemplary components of a portion of the environment of  FIG. 1 ; 
         FIG. 3  is a diagram illustrating exemplary components of a device that may be included in a component of  FIG. 1  or  FIG. 2  according to an implementation described herein; 
         FIG. 4  is a diagram of an exemplary signal flow according to an implementation described herein; and 
         FIG. 5  is a flowchart of a process for implementing a policy control associations establishment procedure according to an implementation described herein. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. 
     As communication networks and services increase in size, complexity, and number of users, network management has become increasingly complex. One way in which wireless access networks are becoming more complicated is by incorporating various aspects of next generation networks, such as Fifth Generation (5G) mobile networks, utilizing high frequency bands (e.g., 24 Gigahertz (GHz), 39 GHz, etc.) and/or lower frequency bands (e.g., sub 6 GHz), and considerably more antennas. 5G technology may provide significant improvements in bandwidth and/or latency over previous wireless network technology. Furthermore, coverage and signal quality may be improved using multiple-input and multiple-output (MIMO) adaptive antenna arrays. Additionally, UE devices may also include multiple antennas to improve spectral efficiency. 
     For a UE device to acquire wireless service of a network, the UE device has to first establish a wireless connection (e.g., a Radio Resource Control (RRC) connection) with a radio access network (RAN), and then authenticate, register, and establish a bearer with a core network. Typically, as part of an attachment procedure with the core network, the UE device receives policies or policy decisions from the core network. For example, the policies may include a UE route selection policy (URSP) for outgoing traffic, a policy for network discovery and selection, a policy pertaining to acceptable service areas and available bandwidth, and/or policies relating to quality of service (QoS) requirements. 
     In practice, because implementations may differ as to whether UE/AM PCF and SM PCF are the same or not, the same PCF can retain all SM, AM, and UE policy control associations for a subscriber. Further, a Uniform Data Repository (UDR) function and an Nudr interface may enable the combination PCF (i.e., a same PCF handling two or more of the AM, UE, and SM policy control) to obtain policy control-related subscription information and application-specific information stored in the UDR. Implementations described herein relate to policy control associations establishment procedures in which the retrieval from the UDR function of policy control-related subscription information and application-specific information, for AM policy data, UE policy data, and SM policy data, may be accomplished in fewer signaling exchanges via the Nudr interface. 
       FIG. 1  is a diagram of an exemplary environment  100  in which the systems and/or methods, described herein, may be implemented. As shown in  FIG. 1 , environment  100  may include UE devices  110 -AA to  110 -NY (referred to herein collectively as “UE devices  110 ” and individually as “UE device  110 ”), a radio access network (RAN)  120 , a core network  130 , and data networks  140 -A to  140 -N. 
     UE device  110  may include any device with long-range (e.g., cellular or mobile wireless network) wireless communication functionality. For example, UE device  110  may include a handheld wireless communication device (e.g., a mobile phone, a smart phone, a tablet device, etc.); a wearable computer device (e.g., a head-mounted display computer device, a head-mounted camera device, a wristwatch computer device, etc.); a laptop computer, a tablet computer, or another type of portable computer; a desktop computer; a customer premises equipment (CPE) device, such as a set-top box or a digital media player (e.g., Apple TV, Google Chromecast, Amazon Fire TV, etc.), a WiFi access point, a smart television, etc.; a portable gaming system; a global positioning system (GPS) device; a home appliance device; a home monitoring device; and/or any other type of computer device with wireless communication capabilities and a user interface. UE device  110  may include capabilities for voice communication, mobile broadband services (e.g., video streaming, real-time gaming, premium Internet access etc.), best effort data traffic, and/or other types of applications. 
     In some implementations, UE device  110  may communicate using machine-to-machine (M2M) communication, such as machine-type communication (MTC), and/or another type of M2M communication. 
     RAN  120  may enable UE devices  110  to connect to core network  130  for mobile telephone service, Short Message Service (SMS) message service, Multimedia Message Service (MMS) message service, Internet access, cloud computing, and/or other types of data services. RAN  120  may include access stations  125 -A to  125 -N (referred to herein collectively as “access stations  125 ” and individually as “access station  125 ”). Each access station  125  may service a set of UE devices  110 . For example, access station  125 -A may service UE devices  110 -AA to  110 -AX, etc., to access station  125 -N, which may service UE devices  110 -NA to  110 -NY. In other words, UE devices  110 -AA to  110 -AX may be located within the geographic area serviced by access station  125 -A, and other UE devices  110  may be serviced by another access station  125 . 
     Access station  125  may include a 5G access device (e.g., a gNodeB (gNB)) that includes one or more radio frequency (RF) transceivers (also referred to as “cells” and/or “access device sectors”) facing particular directions. In some implementations, access station  125  may also include a 4G access device (e.g., an eNodeB (eNB)). Furthermore, in some implementations, access station  125  may include a mobile edge computing (MEC) system that performs cloud computing and/or network processing services for UE devices  110 . 
     Core network  130  may manage communication sessions for UE devices  110 . For example, core network  130  may establish an Internet Protocol (IP) connection between UE device  110  and a particular data network  140 . Furthermore, core network  130  may enable UE device  110  to communicate with an application server, and/or another type of device, located in a particular data network  140  using a communication method that does not require the establishment of an IP connection between UE device  110  and data network  140 , such as, for example, Data over Non-Access Stratum (DoNAS). 
     In some implementations, core network  130  may include a Long Term Evolution (LTE) access network (e.g., an evolved packet core (EPC) network). In other implementations, core network  130  may include a Code Division Multiple Access (CDMA) access network. For example, the CDMA access network may include a CDMA enhanced High Rate Packet Data (eHRPD) network (which may provide access to an LTE access network). 
     Furthermore, core network  130  may include an LTE Advanced (LTE-A) access network and/or a 5G core network or other advanced network that includes functionality such as management of 5G NR access devices; carrier aggregation; advanced or massive multiple-input and multiple-output (MIMO) configurations (e.g., an  8 x 8  antenna configuration, a  16 x 16  antenna configuration, a 256×256 antenna configuration, etc.); cooperative MIMO (CO-MIMO); relay stations; Heterogeneous Networks (HetNets) of overlapping small cells and macrocells; Self-Organizing Network (SON) functionality; MTC functionality, such as 1.4 MHz wide enhanced MTC (eMTC) channels (also referred to as category Cat-M1), Low Power Wide Area (LPWA) technology such as Narrow Band (NB) IoT (NB-IoT) technology, and/or other types of MTC technology; and/or other types of LTE-A and/or 5G functionality. 
     Data networks  140 -A to  140 -N (referred to herein collectively as “data networks  140 ” and individually as “data network  140 ”) may each include a packet data network (PDN). A particular data network  140  may include, and/or be connected to and enable communication with, a local area network (LAN), a wide area network (WAN), a metropolitan area network (MAN), an optical network, a cable television network, a satellite network, a wireless network (e.g., a CDMA network, a general packet radio service (GPRS) network, and/or an LTE network), an ad hoc network, a telephone network (e.g., the Public Switched Telephone Network (PSTN) or a cellular network), an intranet, or a combination of networks. Some or all of a particular data network  140  may be managed by a communication services provider that also manages core network  130 , RAN  120 , and/or particular UE devices  110 . For example, in some implementations, a particular data network  140  may include an IP Multimedia Sub-system (IMS) network (not shown in  FIG. 1 ). An IMS network may include a network for delivering IP multimedia services and may provide media flows between two different UE devices  110 , and/or between a particular UE device  110  and external IP networks or external circuit-switched networks (not shown in  FIG. 1 ). 
     Although  FIG. 1  shows exemplary components of environment  100 , in other implementations, environment  100  may include fewer components, different components, differently arranged components, or additional components than depicted in  FIG. 1 . Additionally or alternatively, one or more components of environment  100  may perform functions described as being performed by one or more other components of environment  100 . 
       FIG. 2  is a diagram illustrating a portion of environment  100  that includes exemplary components of core network  130  in the context of environment  100  according to an implementation described herein. As shown in  FIG. 2 , the portion of environment  100  may include UE device  110 , gNodeB (gNB)  210 , core network  130 , and data network  140 . 
     gNB  210  (corresponding to access station  125 ) may include one or more devices (e.g., access devices) and other components and functionality that enable UE device  110  to wirelessly connect to RAN  120  using 5G NR RAT. For example, gNB  210  may service one or more cells, with each cell being served by a wireless transceiver with an antenna array configured for mmWave wireless communication. gNB  210  may correspond to access station  125 . gNB  210  may communicate with an Access and Mobility Management Function (AMF)  220  using an N 2  interface  212  and communicate with a User Plane Function (UPF)  230  using an N 3  interface  214 . 
     Core network  130  may include AMF  220 , UPF  230 , an SMF  240 , an Application Function (AF)  250 , a Unified Data Repository (UDR)  252 , a Policy Control Function (PCF)  254 , a Charging Function (CHF)  256 , a Network Repository Function (NRF)  258 , a Network Exposure Function (NEF)  260 , a Unified Data Management (UDM) function  262 , an Authentication Server Function (AUSF)  264 , a 5G Equipment Identity Register (EIR)  266 , a Network Data Analytics Function (NWDAF)  268 , a Short Message Service Function (SMSF)  270 , a Network Slice Selection Function (NSSF)  272 , and a Non-3GPP Inter-Working Function (N3IWF)  274 . 
     The components depicted in  FIG. 2  may be implemented as dedicated hardware components or as virtualized functions implemented on top of a common shared physical infrastructure using software-defined networking (SDN). For example, an SDN controller may implement one or more of the components of  FIG. 2  using an adapter implementing a virtual network function (VNF) virtual machine, an event driven serverless architecture interface, and/or another type of SDN architecture. The common shared physical infrastructure may be implemented using one or more devices  300  described below with reference to  FIG. 3  in a cloud computing center associated with core network  130 . Additionally, or alternatively, some, or all, of the common shared physical infrastructure may be implemented using one or more devices  300  described below with reference to  FIG. 3  using a MEC system associated with access stations  125 . 
     AMF  220  may be a network element that is capable of performing registration management, connection management, reachability management, mobility management, lawful intercepts, SMS transport between UE device  110  and SMSF  270 , session management messages transport between UE device  110  and SMF  240 , access authentication and authorization, location services management, functionality to support non-3GPP access networks, and/or other types of management processes. AMF  220  may be accessible by other function nodes via an Namf interface  222 . 
     UPF  230  may be a network element that is capable of maintaining an anchor point for intra/inter-RAT mobility, maintain an external Packet Data Unit (PDU) point of interconnect to a particular data network  140 , perform packet routing and forwarding, perform the user plane part of policy rule enforcement, perform packet inspection, perform lawful intercept, perform traffic usage reporting, perform QoS handling in the user plane, perform uplink traffic verification, perform transport level packet marking, perform downlink packet buffering, forward an “end marker” to a RAN node (e.g., gNB  210 ), and/or perform other types of user plane processes. UPF  230  may communicate with SMF  240  using an N 4  interface  232  and connect to data network  140  using an N 6  interface  234 . 
     SMF  240  may be a network element that is capable of performing session establishment, session modification, and/or session release, perform IP address allocation and management, perform Dynamic Host Configuration Protocol (DHCP) functions, perform selection and control of UPF  230 , configure traffic steering at UPF  230  to guide the traffic to the correct destinations, terminate interfaces toward PCF  254 , perform lawful intercepts, charge data collection, support charging interfaces, control and coordinate of charging data collection, terminate session management parts of NAS messages, perform downlink data notification, manage roaming functionality, and/or perform other types of control plane processes for managing user plane data. SMF  240  may be accessible via an Nsmf interface  242 . 
     AF  250  may be a network element that is capable of providing services associated with a particular application, such as, for example, an application for influencing traffic routing, an application for accessing NEF  260 , an application for interacting with a policy framework for policy control, and/or other types of applications. AF  250  may be accessible via an Naf interface  251 . 
     UDR  252  may be a network element that is capable of providing a unified data structure that is accessible to a number of functional elements. For example, UDR  252  may support storage and retrieval of subscription data by UDM  262 , storage and retrieval of policy data by PCF  254 , storage and retrieval of structured data for exposure, and application data by NEF  260 . UDR  252  may be accessible via an Nudr interface  253 . 
     PCF  254  may be a network element that is capable of supporting policies to control network behavior, provide policy rules to control plane functions (e.g., to SMF  240 ), access subscription information relevant to policy decisions, perform policy decisions, and/or perform other types of processes associated with policy enforcement. PCF  254  may be accessible via Npcf interface  255 . CHF  256  may perform charging and/or billing functions for core network  130 . CHF  256  may be accessible via Nchf interface  257 . 
     NRF  258  may be a network element that is capable of supporting a service discovery function and maintain profiles of available network function (NF) devices/instances and their supported services. An NF profile may include an NF instance identifier (ID), an NF type, a Public Land Mobile Network (PLMN) ID associated with the NF, network slice IDs associated with the NF, capacity information for the NF, service authorization information for the NF, supported services associated with the NF, endpoint information for each supported service associated with the NF, and/or other types of NF information. Additionally, NRF  258  may include one or more transport network KPIs associated with the NF device/instance. NRF  258  may be accessible via an Nnrf interface  259 . 
     NEF  260  may be a network element that is capable of exposing capabilities and events to other NFs, including third party NFs, AFs, edge computing NFs, and/or other types of NFs. Furthermore, NEF  258  may secure provisioning of information from external applications to core network  130 , translate information between core network  130  and devices/networks external to core network  130 , support a Packet Flow Description (PFD) function, and/or perform other types of network exposure functions. NEF  260  may be accessible via an Nnef interface  261 . 
     UDM  262  may be a network element that is capable of maintaining subscription information for UE devices  110 , manage subscriptions, generate authentication credentials, handle user identification, perform access authorization based on subscription data, perform network function registration management, maintain service and/or session continuity by maintaining assignment of SMF  240  for ongoing sessions, support SMS delivery, support lawful intercept functionality, and/or perform other processes associated with managing user data. UDM  262  may be accessible via an Nudm interface  263 . 
     AUSF  264  may be a network element that is capable of performing authentication. For example, AUSF  264  may implement an Extensible Authentication Protocol (EAP) authentication server and may store authentication keys for UE devices  110 . AUSF  264  may be accessible via an Nausf interface  265 . EIR  266  may authenticate a particular UE device  110  based on UE device identity, such as a Permanent Equipment Identifier (PEI). For example, EIR  266  may check to see if a PEI has been blacklisted. EIR  266  may be accessible via an Neir interface  267 . 
     NWDAF  268  may be a network element that is capable of collecting analytics information associated with RAN  120  and/or core network  130 . For example, NWDAF  268  may collect accessibility KPIs (e.g., an RRC setup success rate, a RAB success rate, etc.), retainability KPIs (e.g., a call drop rate, etc.), mobility KPIs (e.g., a handover success rate, etc.), service integrity KPIs (e.g., downlink average throughput, downlink maximum throughput, uplink average throughput, uplink maximum throughput, etc.), utilization KPIs (e.g., resource block utilization rate, average processor load, etc.), availability KPIs (e.g., radio network unavailability rate, etc.), traffic KPIs (e.g., downlink traffic volume, uplink traffic volume, average number of users, maximum number of users, a number of voice bearers, a number of video bearers, etc.), response time KPIs (e.g., latency, packet arrival time, etc.), and/or other types of wireless network KPIs. 
     SMSF  270  may be a network element that is capable of performing SMS services for UE devices  110 . SMSF  270  may be accessible via an Nsmsf interface  271 . NSSF  272  includes one or more devices that select network slice instances for UE device  110 . By providing network slicing, NSSF  220  allows an operator to deploy multiple substantially independent end-to-end networks potentially with the same infrastructure. In some implementations, each slice can be customized for different services. NSSF  272  maybe accessible via an Nnssf interface  273 . 
     N3IWF  274  may be a network element that is capable of interconnecting to a non-3GPP access device, such as, for example, a WiFi access point (not shown in  FIG. 2 ). N3IWF  274  may facilitate handovers for UE device  110  between RAN  120  and the non-3GPP access device. N3IWF  274  maybe accessible via an Nn 3 iwf interface  275 . 
     Although  FIG. 2  shows exemplary components of core network  130 , in other implementations, core network  130  may include fewer components, different components, differently arranged components, or additional components than depicted in  FIG. 2 . Additionally or alternatively, one or more components of core network  130  may perform functions described as being performed by one or more other components of core network  130 . For example, core network  130  may include additional function nodes not shown in  FIG. 2 , such as a Security Edge Protection Proxy (SEPP), an Unstructured Data Storage Network Function (UDSF), a Location Management Function (LMF), a Lawful Intercept Function (LIF), a binding session function (BSF), and/or other types of functions. Furthermore, while particular interfaces have been described with respect to particular function nodes in  FIG. 2 , additionally, or alternatively, core network  130  may include a reference point architecture that includes point-to-point interfaces between particular function nodes. 
       FIG. 3  is a diagram illustrating example components of a device  300  according to an implementation described herein. UE device  110 , gNB  210 , AMF  220 , UPF  230 , SMF  240 , AF  250 , UDR  252 , PCF  254 , CHF  256 , NRF  258 , NEF  260 , UDM  262 , AUSF  264 , EIR  266 , NWDAF  268 , SMSF  270 , NSSF  272 , N3IWF  274 , and/or other components of core network  130 , may each include one or more devices  300 . As shown in  FIG. 3 , device  300  may include a bus  310 , a processor  320 , a memory  330 , an input device  340 , an output device  350 , and a communication interface  360 . 
     Bus  310  may include a path that permits communication among the components of device  300 . Processor  320  may include any type of single-core processor, multi-core processor, microprocessor, latch-based processor, and/or processing logic (or families of processors, microprocessors, and/or processing logics) that interprets and executes instructions. In other embodiments, processor  320  may include an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), and/or another type of integrated circuit or processing logic. 
     Memory  330  may include any type of dynamic storage device that may store information and/or instructions, for execution by processor  320 , and/or any type of non-volatile storage device that may store information for use by processor  320 . For example, memory  330  may include a random access memory (RAM) or another type of dynamic storage device, a read-only memory (ROM) device or another type of static storage device, a content addressable memory (CAM), a magnetic and/or optical recording memory device and its corresponding drive (e.g., a hard disk drive, optical drive, etc.), and/or a removable form of memory, such as a flash memory. 
     Input device  340  may allow an operator to input information into device  300 . Input device  340  may include, for example, a keyboard, a mouse, a pen, a microphone, a remote control, an audio capture device, an image and/or video capture device, a touch-screen display, and/or another type of input device. In some embodiments, device  300  may be managed remotely and may not include input device  340 . In other words, device  300  may be “headless” and may not include a keyboard, for example. 
     Output device  350  may output information to an operator of device  300 . Output device  350  may include a display, a printer, a speaker, and/or another type of output device. For example, device  300  may include a display, which may include a liquid-crystal display (LCD) for displaying content to the customer. In some embodiments, device  300  may be managed remotely and may not include output device  350 . In other words, device  300  may be “headless” and may not include a display, for example. 
     Communication interface  360  may include a transceiver that enables device  300  to communicate with other devices and/or systems via wireless communications (e.g., radio frequency, infrared, and/or visual optics, etc.), wired communications (e.g., conductive wire, twisted pair cable, coaxial cable, transmission line, fiber optic cable, and/or waveguide, etc.), or a combination of wireless and wired communications. Communication interface  360  may include a transmitter that converts baseband signals to radio frequency (RF) signals and/or a receiver that converts RF signals to baseband signals. Communication interface  360  may be coupled to one or more antennas/antenna arrays for transmitting and receiving RF signals. 
     Communication interface  360  may include a logical component that includes input and/or output ports, input and/or output systems, and/or other input and output components that facilitate the transmission of data to other devices. For example, communication interface  360  may include a network interface card (e.g., Ethernet card) for wired communications and/or a wireless network interface (e.g., a WiFi) card for wireless communications. Communication interface  360  may also include a universal serial bus (USB) port for communications over a cable, a Bluetooth™ wireless interface, a radio-frequency identification (RFID) interface, a near-field communications (NFC) wireless interface, and/or any other type of interface that converts data from one form to another form. 
     As will be described in detail below, device  300  may perform certain operations relating to establishing AM, UE, and SM policy control associations relating to subscription information and application-specific information. Device  300  may perform these operations in response to processor  320  executing software instructions contained in a computer-readable medium, such as memory  330 . A computer-readable medium may be defined as a non-transitory memory device. A memory device may be implemented within a single physical memory device or spread across multiple physical memory devices. The software instructions may be read into memory  330  from another computer-readable medium or from another device. The software instructions contained in memory  330  may cause processor  320  to perform processes described herein. Alternatively, hardwired circuitry may be used in place of, or in combination with, software instructions to implement processes described herein. Thus, implementations described herein are not limited to any specific combination of hardware circuitry and software. 
     Although  FIG. 3  shows exemplary components of device  300 , in other implementations, device  300  may include fewer components, different components, additional components, or differently arranged components than depicted in  FIG. 3 . Additionally, or alternatively, one or more components of device  300  may perform one or more tasks described as being performed by one or more other components of device  300 . 
       FIG. 4  is a diagram of an exemplary signal flow  400  that depicts exemplary interactions between the components of a portion of environment  130  described above in accordance with  FIG. 2 . It should be understood that the signaling depicted in  FIG. 4  is abbreviated to highlight concepts described herein and that, in practice, additional signals/messages beyond those shown in  FIG. 4  are exchanged between NFs to provide network services. 
     As shown in  FIG. 4 , signal flow  400  may include UE device  110  (also referred to herein as UE  110 ) exchanging registration request signaling with RAN  120  (signal  405 ). For example, UE  110  may initiate Radio Resource Control (RRC) session establishment with gNB  210 . In response, RAN  120  may select and register UE  110  with an appropriate AMF  220  (signal  410 ). For example, gNB  210  may initiate an AMF selection process. Using the selected AMF  220 , RAN  120  and AMF  220  perform registration and authentication processing (block  415 ). For example, AMF  220  may select an appropriate AUSF  264  (not shown in  FIG. 4 ) and may authenticate the registration request from UE  110  using the selected AUSF  264 . 
     Following authentication, AMF  220  may discover and select PCF  254  (block  420 ). Using selected PCF  154 , AMF  220  may initiate AM policy enforcement via Npcf interface  255 . For example, AMF  220  may request creation of an AM policy control association in PCF  254  (referred to as Npcf_AMPolicyControl_Create) for identified UE  110  (signal  425 ). Such a request may include various UE-related and/or subscriber information, such as its subscription permanent identifier (SUPI), Internal Group identifier, subscription notification indication, Service Area Restrictions, RAT/frequency selection priority (RFSP) index, Allowed network slice selection assistance information (NSSAI), general public subscription identifier (GPSI), Access Type and RAT, permanent equipment identifier (PEI), and/or time zone. 
     In response to the request and according to configuration/policy design, PCF  254  may query UDR  252  for any combination of AM, UE, and SM policy data (referred to as Nudr_DataRepository_Query (AM/UE/SM Policy Data)) (signal  430 ). For example, the UE policy data may include various UE-related and/or subscriber information, such as UE route selection policy (URSP), network discovery and selection (e.g., wireless local area network (WLAN) selection information, non-3rd Generation Partnership Project (3GPP) interworking function (N3IWF) selection information, evolved packet data gateway (ePDG) selection information), acceptable service areas (e.g., list of allowed/non-allowed tracking area identifiers (TAIs)) and available bandwidth (e.g., radio access technology (RAT) frequency selection priority (RFSP)), and/or QoS requirements. PCF  254  may store the combination of AM, UE, and SM policy data with any available identification and/or indexing information, such as the SUPI associated with registered UE  110  (block  435 ). In one implementation, PCF  254  requests notifications from UDR  252  (block  440 ) indicating subsequent changes in subscription information for any combination of AM, UE, and SM policy data (referred to as Nudr_DataRepository_Subscribe (AM/UE/SM Policy Data)). 
     After retrieving and storing the requested combination of AM, UE, and SM policy data, PCF  254  transmits a decision regarding access back to AMF  220  (e.g., block  425 ). AMF  220  then deploys or enforces the received decision/AM policy when determining whether to register UE  110 . Assuming that an affirmative policy decision is received by AMF  220  (for the purposes of  FIG. 4 ), AMF  220 , RAN  210  and UE  110  finalize registration of UE  110  onto the core network  130  (block  445 ) and establish the AM policy control association. 
     AMF  220  may initiate UE policy enforcement via Npcf interface  255 . For example, AMF  220  may request creation of a UE policy control association (signal  450 ) in PCF  254  (referred to as Npcf_UEPolicyControl_Create). Such a request may include the various UE-related and/or subscriber information previously retrieved and stored by PCF  254 , as described above. AMF  220  and PCF  254  may use the stored UE policy data to complete the establishment of the UE policy control association (e.g., signal  450 ). 
     As shown in  FIG. 4 , once the UE policy control association is established, creation of a PDU session is permitted to enable data to flow between UE  110  and data network  140 . In block  455 , PDU session creation may be initiated and include, among other operations, selection of a suitable SMF  240  by AMF  220  and selection of a suitable PCF  254  by SMF  240 . As described above, current standard-based signaling does not require that AMF  220  and SMF  240  select a same PCF  254 . However, consistent with existing standards, AMF  220  does provide a PCF identifier to SMF  240  during PDU session establishment. Based on various criteria, such as operator policies, SMF  240  may determine whether to use the identified PCF for session SM policy decisions. For the purposes of this description, it is assumed that SMF  240  has determined to use the identified PCF  254  for SM policy determination. 
     As part of its policy framework, SMF  240  is configured to create associations between the PDU session being established and any SM policies that may apply to the particular PDU session. Such associations are established by SMF  240  querying PCF  254  for applicable SM policy decisions (signal  460 ). Such a request, referred to as Npcf_SMPolicyControl_Create, may include various elements of information, such as: SUPI, PDU Session ID, PDU Session Type, DNN, Access Type, AMF instance identifier, UE network address, PEI, User Location Information, Time Zone, Serving Network, RAT type, Charging Characteristics, Session AMBR, default QoS information, Internal and Group Identifier. 
     Consistent with implementations described herein, in addition to the SM policy rules themselves, which may be stored within or otherwise available from PCF  254 , and the information received from SMF  240 , PCF  254  may identify the SM policies for enforcement as and may render appropriate SM policy decisions (block  465 ) and transmit such decisions to SMF  240  (e.g., signal  460 ). Based on these decisions, and the establishment of the SM policy control associations, the PDU session may (or may not) be established by SMF  240  (block  470 ) for UE  110  via RAN  120 . 
       FIG. 5  is a flowchart of a process  500  for establishing one or more of AM, UE, and SM policy control associations according to an implementation described herein. In some implementations, the process of  FIG. 5  may be performed by PCF  254 . In other implementations, some or all of process  500  may be performed by another device or a group of devices separate from PCF  254 . 
     Process  500  may include PCF  254  receiving an AM policy control association request via Npcf interface  255  (Npcf_AM_PolicyControl_Create) from AMF  220  in relation to a registration request from a subscriber at UE  110  (block  505 ). For example, as described above, following receipt of a registration request by AMF  220  from UE  110  (via RAN  120 ), AMF  220  may discover and select PCF  254  and may initiate registration and/or authentication with RAN  120  on behalf of UE  110 . The Npcf_AMPolicyControl_Create request may include various elements relating to UE  110 , such as the subscriber&#39;s SUPI, the PDU session ID, the DNN, and the S-NSSAI, among other information. Upon receipt of the AM policy association request from AMF  220 , PCF  254  generates e.g., using an extension to Nudr interface  253  (Nudr_DataRepository_Query (AM/UE/SM Policy Data)), a query for AM policy control data and one or both of UE policy control data and SM policy control data stored in UDR  252  (block  510 ). Based on the response from UDR  252 , PCF  254  may store the obtained data, and forward AM policy decisions to AMF  220  and establish AM policy control association (block  515 ). 
     Process  500  may further include PCF  254  receiving a UE policy control association request via Npcf interface  255  (Npcf_UE PolicyControl_Create) from AMF  220  in relation to the PDU session establishment request from the subscriber at UE  110  (block  520 ). PCF  254  may determine whether UE policy control data has already been retrieved from UDR  252  (e.g., from block  510 ) and is currently stored at PCF  254  (block  525 ). If PCF  254  determines that it does not have the UE policy control data (block  525 —NO), PCF  254  may query, via Nudr interface  253  (Nudr DataRepoistory Query), UDR  252  for the UE policy control data (block  530 ). PCF  254  may establish the UE policy control association using the obtained data (block  535 ). Alternatively, if PCF  254  determines that, from performing block  510 , it does have the UE policy control data (block  525 —YES), PCF  254  may establish the UE policy control association using the stored data (block  535 ). 
     Process  500  may include receiving an SM policy association request via Npcf interface  255  (Npcf_SMPolicyControl_Create) from SMF  240  in relation to the PDU session establishment request (block  540 ). As part of the request, SMF  240  discovers (e.g., from NRF  258 ) and selects a PCF  254  and transmits the Npcf_SMPolicyControl_Create request to the selected PCF. The Npcf_SMPolicyControl_Create request may include various elements relating to UE  110  and the requested PDU session, such as the subscriber&#39;s SUPI, the PDU session ID, the DNN, and the S-NSSAI, among other information. Consistent with embodiments described herein, the SM policy association request may also include the PCF ID relating to PCF  254  selected and used by AMF  220  during UE registration, as described above. 
     Process  500  may further include PCF  254  receiving a SM policy control association request via Npcf interface  255  (Npcf_SM_PolicyControl_Create) from SMF  240  in relation to the PDU session establishment request from the subscriber at UE  110  (block  540 ). PCF  254  may determine whether SM policy control data has already been retrieved from UDR  252  (e.g., from block  510 ) and is currently stored at PCF  254  (block  545 ). If PCF  254  determines that it does not have the SM policy control data (block  545 —NO), PCF  254  may query, via Nudr interface  253  (Nudr_DataRepoistory_Query), UDR  252  for the SM policy control data (block  550 ). PCF  254  may establish the SM policy control association using the obtained data (block  555 ). Alternatively, if PCF  254  determines that, from performing block  510 , it does have the SM policy control data (block  545 —YES), PCF  254  may establish the SM policy control association using the stored data (block  555 ). 
     Various embodiments described herein relate to AM, UE, and/or SM policy control associations establishment procedures that reduce the amount of signaling that is performed using existing standard-based signaling. In one example, a service-based network interface is modified with an extension such that any combination of AM policy control data, UE policy control data, and/or SM policy control data can be queried in fewer than three messages, for example, in two messages or in a single message. In another embodiment, a service-based network interface is modified with an extension such that any combination of AM policy control data, UE policy control data, and/or SM policy control data can be subscribed to for subsequent change notifications, in fewer than three messages, for example, in two messages or in a single message. 
     In the preceding specification, various preferred embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. 
     For example, while a series of messaging and operations have been described with respect to  FIG. 4  and a series of blocks have been described with respect to  FIG. 5  the order of the signals and/or blocks may be modified in other implementations. Further, non-dependent messaging and operations and/or blocks may be performed in parallel, were appropriate. 
     It will be apparent that systems and/or methods, as described above, may be implemented in many different forms of software, firmware, and hardware in the implementations illustrated in the figures. The actual software code or specialized control hardware used to implement these systems and methods is not limiting of the embodiments. Thus, the operation and behavior of the systems and methods were described without reference to the specific software code—it being understood that software and control hardware can be designed to implement the systems and methods based on the description herein. 
     Further, certain portions, described above, may be implemented as a component that performs one or more functions. A component, as used herein, may include hardware, such as a processor, an ASIC, or an FPGA, or a combination of hardware and software (e.g., a processor executing software). 
     It should be emphasized that the terms “comprises”/“comprising” when used in this specification are taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof 
     The term “logic,” as used herein, may refer to a combination of one or more processors configured to execute instructions stored in one or more memory devices, may refer to hardwired circuitry, and/or may refer to a combination thereof. Furthermore, a logic may be included in a single device or may be distributed across multiple, and possibly remote, devices. 
     For the purposes of describing and defining the present invention, it is additionally noted that the term “substantially” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “substantially” is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. 
     To the extent the aforementioned embodiments collect, store, or employ personal information of individuals, it should be understood that such information shall be collected, stored, and used in accordance with all applicable laws concerning protection of personal information. Additionally, the collection, storage and use of such information may be subject to consent of the individual to such activity, for example, through well known “opt-in” or “opt-out” processes as may be appropriate for the situation and type of information. Storage and use of personal information may be in an appropriately secure manner reflective of the type of information, for example, through various encryption and anonymization techniques for particularly sensitive information. 
     No element, act, or instruction used in the present application should be construed as critical or essential to the embodiments unless explicitly described as such. Also, as used herein, the article “a” is intended to include one or more items. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.