Mobile network user plane with access network user plane function

Abstract

Embodiments of the present disclosure relate to mobile network user plane with access network user plane function. In one example, a method includes performing, by an access network user plane function (ANUP) for a mobile network, an access network protocol to enable a connection with a user equipment (UE); enabling, by the ANUP, an interface with a data network based on session data received from a control plane function of a mobile core network for the mobile network; and routing or switching, by the ANUP, packets between the connection with the UE and the interface with the data network.

Description

[0001] This application claims the benefit of U.S. Patent Application No. 17 / 657,582, filed March 31, 2022, and U.S. Provisional Patent Application No. 63 / 264,075, filed November 15, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to computer networking, and more specifically, to mobile networks connected to data networks. Background Technology

[0003] Computer networks have become ubiquitous, and network applications, the number of network-connected devices, and the types of network-connected devices are rapidly expanding. Such devices now include computers, smartphones, Internet of Things (IoT) devices, automobiles, medical equipment, factory equipment, and more. End-user network-connected devices typically do not have direct access to public networks such as the Internet. Instead, end-user network devices establish network connections with access networks, and access networks communicate with core networks connected to one or more packet data networks (PDNs) providing the service.

[0004] Mobile networks include one or more radio access networks (RANs) that serve as access networks within 3GPP (3rd Generation Partnership Project) networks, trusted and untrusted non-3GPP networks such as Wi-Fi or WiMAX networks, and fixed / wired networks such as digital subscriber line (DSL), passive optical network (PON), and cable networks. The mobile core network can be a mobile service provider network, such as 3G, 4G / LTE, or 5G networks. Summary of the Invention

[0005] In summary, this disclosure describes techniques for integrating various aspects of the mobile network user plane to simplify user data exchange between the UE (User Equipment) and the data network (DN) providing services to the UE. In the 3GPP 5G specification, the user plane includes a tunnel for the N3 interface, which transmits user data traffic between the RAN (Radio Access Network) and the User Plane Functions (UPFs) in the mobile core network, and the UPF acts as a session anchor for PDU (Protocol Data Unit) sessions. Furthermore, the UPF can be serially connected to one or more other UPFs via the N9 interface. Because the 3GPP 5G specification specifies that all N3 and N9 tunneling uses GTP [GPRS ​​(General Packet Radio Service) Tunneling Protocol)], which involves additional encapsulation of the underlying data, eliminating N3 tunneling would be advantageous.

[0006] In 5G mobile network systems, N3 tunneling can be performed over an IP-VPN within the transport infrastructure, typically serving both fixed and mobile networks. The UPF is usually deployed in a centralized location within the core network, and as mentioned above, the N3 / N9 tunnel extends the PDU layer to and within the UPF. The UPF terminates PDU sessions to / from the data network (DN), where each session can be a VPN over the transport infrastructure. Centralized UPFs maintain per-session state for thousands of UEs [according to PDR (Packet Detection Rules) and FAR (Forwarding Action Rules)], and are typically used in large systems serving hundreds or thousands of gNodeBs (base stations). The RAN's gNodeBs connect the N3 tunnels to the radio bearers implemented at the base stations.

[0007] In some implementations of the 5G mobile network user plane, UPFs are not centralized but rather distributed closer to the RAN and mobile core network edge, allowing them to be co-located with the RAN's gNodeBs (i.e., in the same data center or even the same server), thereby facilitating multi-access edge processing. In co-location examples, the N3 interface can be simplified to a direct and / or internal connection between the gNodeB and the UPF. Because the UPF-DN connection is direct, the connection link becomes the same transport infrastructure over which the VPN (e.g., IPVPN in the case of IP PDU sessions) is located, most likely the same transport infrastructure used for VPNs supporting N3 / N9 tunneling.

[0008] In some examples of the mobile network user plane described herein, at least some aspects of user plane functions and gNodeB / RAN functions are integrated into a single network function that can be deployed to support base stations. This integrated network function is referred to herein as the Access Network (and / plus) User Plane Function (ANUP) to reflect that it is a combination of access network gNodeB functions (AN functions) and user plane functions. This integrated single network function can be implemented in future generations (“xG”) of 3GPP mobile networks where the 3GPP standard does not require N3 tunneling between the access network function and the UPF.

[0009] The technology disclosed herein offers advantages over previous systems. For example, it can simplify and, in some cases, completely eliminate the N3 interface and its corresponding encapsulation requirements, replacing it with IP-VPN and introducing IETF (Internet Engineering Task Force) standards into “mobile core networks” using packet transport, while preserving 3GPP standards for radio links used in the RAN. Various VPN-compatible tunneling technologies can be used, including but not limited to segmented routing (e.g., SRv6), and tunnels can be per VRF (virtual routing and forwarding) or per session. In effect, the VPN technology achieves what was previously accomplished using N3 tunnels (and some deployed N9 tunnels). This contrasts with other proposals to extend N3 tunnels to the DN.

[0010] Consistent with the integration of IP-VPN, host routes advertised by the ANUP to the DN can replace per-session PDR / FAR rules and, in some cases, eliminate the General Packet Radio Service (GPRS) Tunneling Protocol (GTP) in the mobile network protocol stack. However, if the ANUP only maintains default routes to some hub routes in the DN (i.e., a hub-and-spoke VPN can be used to reduce host routes on most ANUPs), the traffic pattern can remain similar to a more centralized UPF deployment. While typically the same amount of state data (per session) is maintained, the total amount of state may be less, given the lighter weight of host routes compared to GTP session data. Host routes are only needed if a persistent UE address is expected after re-anchoring. Additional advantages can include seamless integration with wired services, native Multi-Access Edge Computing (MEC) and simpler multicast and broadcast services (MBS) / 5GLAN, and reduced operating costs due to the combined ANUP and the absence of separate UPF management.

[0011] In one example, this disclosure describes an Access Network User Plane Function (ANUP) for a mobile network. The ANUP includes processing circuitry and is configured to: execute access network protocols to establish a connection with a User Equipment (UE); interface with a data network based on session data received from a control plane function of the mobile core network for the mobile network; and route or exchange packets between the connection with the UE and the interface with the data network.

[0012] In another example, this disclosure describes a mobile network system including: a mobile core network with control plane functions, and an access network user plane function (ANUP) for the mobile network. The ANUP is configured to: execute access network protocols to establish a connection with a user equipment (UE), interface with a data network based on session data received from the control plane functions of the mobile core network for the mobile network, and route or exchange packets between the connection with the UE and the interface with the data network.

[0013] In another example, this disclosure describes a method comprising: executing an access network protocol by an access network user plane function (ANUP) of a mobile network to establish a connection with a user equipment (UE); interfacing with a data network by the ANUP based on session data received from a control plane function of a mobile core network for the mobile network; and routing or exchanging packets between the connection with the UE and the interface with the data network by the ANUP.

[0014] Details of one or more examples are set forth in the accompanying drawings and the following description. Other features, objects, and advantages will be apparent from the specification, drawings, and claims.

[0015] Details of one or more examples are set forth in the accompanying drawings and the following description. Other features, objects, and advantages will become apparent from the specification, the drawings, and the claims. Attached Figure Description

[0016] Figure 1A This is a block diagram illustrating an example 5G mobile network system.

[0017] Figure 1B A hybrid system and protocol diagram of the user plane of an example 5G mobile network system is depicted.

[0018] Figure 2 A hybrid system and protocol diagram of the user plane of an example 5G mobile network system with a distributed UPF is depicted.

[0019] Figure 3A This is a block diagram illustrating an example xG mobile network system with a mobile network according to the technology of this disclosure, wherein the access network user plane function (ANUP) implements a combination of access network / gNodeB and user plane functions.

[0020] Figure 3B A hybrid system and protocol diagram of the user plane of an example xG mobile network system according to the technology of this disclosure is depicted. This example xG mobile network system can be considered as follows: Figure 2 Further evolution of the distributed UPF deployment and implementation of the described mobile network system.

[0021] Figure 4The network functions and interfaces of a public land mobile network (PLMN), including VPLMN (visited PLMN) and HPLMN (home PLMN), are described.

[0022] Figure 5 A network reference model for pseudowire (PW) simulation is depicted.

[0023] Figure 6 An example protocol stack in home-roaming based on the techniques of this disclosure is depicted.

[0024] Figure 7 This is a block diagram illustrating details of an example of an ANUP computing device operating according to one or more techniques disclosed herein. Detailed Implementation

[0025] Figure 1A This is a block diagram illustrating an example 5G mobile network system 100. The example network system 100 implements Control Plane-User Plane Separation (CUPS). CUPS refers to the separation between network management (control) functions and network data traffic forwarding (user) functions. For example, control plane functions may include user connection management, route determination, QoS (Quality of Service) policy definition and enforcement, user authentication, etc. User plane functions typically include the ability to forward network traffic from one node to another. Separation between user plane functions and control plane functions can be beneficial because it facilitates scaling of user plane functionality that is separated from control plane functions.

[0026] exist Figure 1A In the example shown, the control plane and user plane components of mobile network system 100 conform to the fifth-generation mobile network (“5G”) specifications published by 3GPP. The user plane may include components that communicatively attach user equipment (UE) 101 to data network 140. In some aspects, data network 140 may be the Internet. UE 101 may be an end-user network device that communicates with other network devices via data network 140 through an operator’s access network. Examples of UE 101 may be devices that communicate with data network 140 via a radio access network such as a 3GPP network. Such devices may include smartphones, laptops, tablets, IoT devices, autonomous vehicles, etc. The techniques disclosed herein are not limited to any particular type of UE 101, mobile network system or protocol, radio access network, or network system.

[0027] Mobile network system 100 includes one or more radio access networks (RANs) 109 and mobile core networks 105. In a 5G mobile system, the radio access network 109 includes gNodeBs. A gNodeB is a 3GPP-compliant implementation of a 5G base station that implements 3GPP-compliant RAN protocols, which may include PHY, Media Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), Serving Data Adaptation Protocol (SDAP), Radio Resource Control (RRC), and New Radio Access Point (NRAP). gNodeB 102 may include radio units (RUs) located at various cellular network sites (“cell sites”), as well as distributed units (DUs) and centralized units (CUs). 5G RUs are hardware-based and used for the user data plane, and each RU includes a LO PHY and an RF transmitter. The LO PHY component can be implemented using dedicated hardware for high-performance packet processing. DUs and CUs are typically implemented as network functions (NFs), also referred to herein as access network functions (AN functions).

[0028] The RU connects to the DU via a fronthaul network. The fronthaul network connects the LO PHY and HI PHY and is used by the RU and DU to implement the 5G F2 interface. The DU manages packet transmissions via the RU. In some cases, this packet transmission conforms to the Common Packet Radio Interface (CPRI) and / or Enhanced CPRI (eCPRI) standards, or to IEEE 1914.3. The DU can implement the RLC, MAC, and HI PHY layers. The DU is controlled at least partially by the CU.

[0029] The DU connects to the CU via the midhaul network, and both the DU and CU can be used to implement the 5G F1 interface. The CU can implement the RRC and PDCP layers. The CU connects to the mobile core network 105 via the backhaul network. Both the midhaul and backhaul networks can be wide area networks (WANs).

[0030] In some examples of the radio access network 109 of the mobile network system 100, the gNodeB 102 includes one CU and one DU. A CU can support multiple DUs to implement multiple gNodeBs. One or more RUs can be supported by a single DU.

[0031] Any DU may or may not be located at a cell site, including the RUs supported by the DU. A DU may be located at a cell site, while other DUs may be located in a local data center and collectively support multiple RUs. The mobile network system 100 may have a radio access network 109 comprising thousands of cell sites and gNodeBs.

[0032] Radio access network 109 connects to mobile core network 105 to exchange packets with data network 140. Mobile core network 105 may be a 5G core network, and data network (DN) 140 may represent, for example, one or more service provider networks and services, the Internet, third-party services, one or more IP-VPNs, IP-Multimedia Subsystems, combinations thereof, other networks, or combinations of networks.

[0033] The core network 105 implemented in 5G is a service-based architecture that includes various interconnected cloud-native network functions (NFs) with authorization to access each other's services. As shown in the figure, the mobile network system 100 includes a core network 105 that implements various discrete control plane functions of the network system 100. In some aspects, the core network 105 includes 5G control plane functions (network functions), such as Access Mobility Management Function (AMF) 152, Session Management Function (SMF) 153, Policy Control Function (PCF) 154, User Data Management (UDM) 155, Network Repository Function (NRF) 157, Authentication Server Function (AUSF) 156, and Network Slice Selection Function (NSSF) 159.

[0034] The AMF 152 communicates with the UE 101 via the N1 control interface. The AMF 152 can also connect to access network functions such as the DU / CU via the N2 interface. The AMF receives all connection and session-related information from the UE via the N1 / N2 interfaces, but is only responsible for handling connection and mobility management tasks. All session management-related messages are forwarded to the SMF via the N11 interface. The SMF 153 communicates with the I-UPF 144 and UPF 146 using the N4 interface. The SMF 153 handles session management, IP address allocation, and policy enforcement control. The AMF 152, SMF 153, PCF 154, UDM 155, NRF 157, AUSF 156, and NSSF 159 are integrated into the core network 105 along with other network functions and services. Further details regarding the services and capabilities offered by AMF 152, SMF 153, PCF154, UDM 155, NRF 157, AUSF 156, and NSSF 159 can be found in: “3rd Generation Partnership Project 2021, Technical Specification Group Services and System Aspects; System architecture for the 5G System (5GS); Stage 2 (Release 17), TS 23.501 V17.0.0 (2021-03)”, the entire contents of which are incorporated herein by reference.

[0035] In 5G, the User Plane Function (UPF) is responsible for packet routing and forwarding under the control of the SMF. The UPF generates billing data records and traffic usage records sent to the SMF and can perform packet inspection and policy application. The N3 interface extends from the gNodeB 102 to the Protocol Data Unit (PDU), Session Anchor Point (PSA), and UPF. Figure 1A The I-UPF 146 used for UE 101, although the I-UPF 144 can mediate traffic between the gNodeB and PSA UPF. In this case, the N9 interface is used between the I-UPF 144 and the PSA UPF 146, as shown in the example. Figure 1A As shown in the example.

[0036] Figure 1B Depicting Figure 1A Example 5G mobile network system 100 user plane hybrid system and protocol diagram 110. The UPF is typically deployed in a central location, and the N3 / N9 tunnel extends the PDU layer from the gNodeB to the UPF and within the UPF. At gNodeB 102, relay / stitching is used to connect the Serving Data Adaptation Protocol (SDAP) layer and the N3 interface. At I-UPF 144, relay / stitching is used to connect N3 and N9. The PSA UPF terminates the N3 or N9 tunnel and (at L3 / L2 levels respectively) performs routing / switching between UE 101 (via PDU session) and data network 140.

[0037] The N3 and N9 interfaces are GTP-U tunnels, which typically use a Virtual Private Network (VPN) implemented over the transport network 141 infrastructure for transmission. GTP-U stands for GPRS (General Packet Radio Traffic) Tunneling Protocol. In other words, GTP-U is used to transmit user data within the core network 105 and between the radio access network and the core network 105. The transmitted user data can be packets in any of the following formats: IPv4, IPv6, or PPP. The transport network 141 can represent a mobile network operator (MNO) network and can include infrastructure shared with the core network 105.

[0038] User data between core network 105 and networks such as transport network 141 / data network 140 uses the N6 interface. Although N6 is a 3GPP-defined interface, it is for reference only—it does not involve tunneling or specifications. The N6 interface is simply a direct IP connection (in the case of an IP PDU session) or Ethernet connection (in the case of an Ethernet PDU session) to data network 140.

[0039] Figure 2Figure 210 depicts a hybrid system and protocol diagram of the user plane of a 5G mobile network system with a distributed UPF. In this case, the N9 interface is absent, and the PSA UPF 146 interfaces with the gNodeB via the N3 interface. In other words, in... Figure 2 The deployment shown eliminates the need for a centralized PSA UPF. Instead, the UE can migrate its session anchor between multiple UPFs distributed across the mobile core network, such as at the access edge. In this example, multiple UPFs 146 are connected to the same data network where a VPN is instantiated and configured in a transport network 141 with provider edge (PE) routers PE1, PE2, and PE3. Each of PEs 1, PE2, and PE3 has a Virtual Router and Forward Instance (VRF) (vrf1 and vrf2) configured on it for the corresponding IP VPN. IP VPNs are described in more detail in Request for Comments 4364, “BGP / MPLSIP Virtual Private Networks (VPNs),” issued by the Internet Engineering Task Force Network Working Group in February 2006, the entirety of which is incorporated herein by reference.

[0040] Figure 2 The exemplary deployments described herein can serve as a general guideline for multi-access edge computing (MEC) (formerly known as mobile edge computing). Edge cloud is an evolution of cloud computing that enables application hosting and data processing to move from centralized data centers to the network edge. Cloud capabilities are distributed across the network, which is particularly useful for applications requiring low latency and / or high bandwidth.

[0041] ETSI has defined a set of technical standards for Multi-Access Edge Computing (MEC), aiming to enable an open ecosystem of service providers and third parties to flexibly and rapidly deploy applications with real-time access to radio network information for optimization. MEC is widely considered one of the key enabling technologies for 5G, particularly its ability to flexibly offload traffic via UPF and its open environment for enabling various vertical applications and services.

[0042] With MEC, more UPFs are distributed closer to the gNodeB. In this case, the N3 interface becomes very simple—via, for example, a direct or short transport connection between gNodeB 102 and UPF 146, or even via an internal connection if gNodeB 102 and UPF 146 are hosted on the same server. On the other hand, since the connection from UPF 146 to data network 140 is direct, the data network becomes a VPN over the transport infrastructure (e.g., an IPVPN in the case of IP PDU sessions), most likely the same transport infrastructure used for VPNs supporting N3 / N9 tunneling.

[0043] Therefore, for distributed UPFs in 5G networks, such as Figure 2 As shown, the transport network infrastructure has elements common to the data network 140, and the data network 140 that provides data packet services to the UE can be an IP-VPN corresponding to either vrf1 or vrf2.

[0044] VPN standards are defined in RFC 4364 and other IETF standards and have been widely deployed in wired networks. Figure 2 In this configuration, the UPF acts as a customer edge device (CE) connected to the PE. Figure 2 In this context, the PE3's VRF can connect to VPN sites on the wired side, including the Internet.

[0045] Figure 2 Two PSAUPFs and two access networks / gNodeBs are shown. If a UE needs to maintain a persistent IP address when it is re-anchored to a different distributed UPF, the anchored UPF can advertise IP host routes (e.g., / 32 routes) using the UE's persistent IP address. Once such a UE is unanchored by a UPF, the UPF can revoke the host routes.

[0046] Figure 3A This is a block diagram illustrating a mobile network system 300 with a radio access network, wherein the access network user plane function (ANUP) 302 implements combined access network functions and user plane functions. Figure 3AAs shown, UE 101 is connected to RU via an over-the-air radio connection, and RU communicates with ANUP 302. ANUP 302 may be implemented by one or more servers, appliances, or other physical network functions or other computing devices. ANUP 302 terminates its PDU session with UE 101 and also has an N6 interface with data network 140. Transport network 141 may include one or more PE routers, P routers, switches, and other network devices to implement IP and / or Layer 2, thereby transmitting IP and / or Ethernet packets between different instances of ANUP for end-user applications operating on the UE and between ANUP 302 and data network 140 services. Transport network 141 and data network 140 may have at least some common infrastructure. Data network 140 may represent an IP VPN or other Layer 3 VPN, the Internet, a cloud service provider network, an IP Multimedia Subsystem (IMS), or other data network or packet data network (PDN).

[0047] ANUP 302 communicates with various network functions (NF1, NF2, NF3, etc.) of the core network 305. In the example shown, AMF 352 and SMF 353 have interfaces N2 and N4 with ANUP 302, respectively, for different functions, which can be analogous to the following... Figure 1A The description describes the functionality of an example 5G network. In some examples, the core network 305 may include other or different network functions or combinations of functions. For example, AMF / SMF may also be combined into a single function, and N2 / N4 may be combined into a common interface.

[0048] Figure 3B The technology according to this disclosure is described Figure 3A The example instance of the mobile network system 300 shown in Figure 310, a hybrid system and protocol diagram, can be considered a further evolution of distributed UPF deployment and has a distributed UPF (with Figure 2 The implementation of a mobile network (the protocol layer depicted in the diagram). UE 318A-318B (collectively referred to as "UE 318") are example instances of user equipment. Figure 3A In this architecture, UPF and access network functions are integrated into Access Network User Plane Functions (ANUP) 320A-320B (collectively referred to as "ANUP 320"), where each ANUP 320 can represent Figure 3AAn example instance of ANUP 302. Each ANUP 320 in ANUP 320 executes the access network protocol used to generate the 3GPP mobile network in which the ANUP is deployed. This can be 6G, 7G, etc., and for this reason, the protocol layer is shown and referred to herein as xG-AN protocol layer 322. xG-AN protocol layer 322 can implement any one or more of the 3GPP-compliant RAN protocols listed above, namely, PHY, MAC, RLC, PDCP, SDAP, RRC, or NRAP defined for 5G. xG-AN protocol layer 322 may include additional access network protocol layers newly defined for xG mobile networks to support the PDU layer for UE connectivity between UE 318 and ANUP 320. xG-AN protocol layer 322 may support RAN protocols.

[0049] Protocol Data Unit (PDU) sessions terminate on the ANUP 320, which performs routing / switching between two stacks (PDU / xG-AN stack (3GPP) and IP / L2 stack (IETF)). Although in Figure 3B The N6 interface is shown, but the N6 interface can be removed, renamed, or considered to be used only for reference in xG.

[0050] In this flattened architecture, IETF and 3GPP technologies are applied where they are most suitable—3GPP for radio access networks, and IETF for the rest, such as transport and data networks. As IETF technologies continue to evolve, they can be automatically applied to mobile networks without any changes to the 3GPP architecture / specifications. For example:

[0051] • Any type of tunnel can be used, such as MPLS or SRv6, which avoids the overhead of UDP / GTP encapsulation on the N3 / N9 interface as in 3GPP networks. Network slicing is supported (the transport network also needs to instantiate slices of the N3 / N9 tunnel).

[0052] 5G-LAN and MEC become native applications (PDU sessions terminate at the nearest ANUP and are routed / switched to different data networks).

[0053] Multicast and Broadcast Services (MBS) become very simple—ANUP obtains multicast traffic from DN and can then send it to interested UEs using a shared radio bearer or a separate bearer.

[0054] In some examples, because the ANUP 320 implements routing / switching functions, one or more functions of the PE function can be optionally integrated into the ANUP 320 to further optimize end-to-end communication by reducing the number of NFs and the connections between them. In fact, the current 5G gNodeBN3 tunnel transport function is similar to the pseudowire (PW) PE function, as described in further detail below.

[0055] The compressed user plane architecture techniques described herein can be used in further iterations of 3GPP standards, such as 6G / 7G / xG (designated "xG" network systems) with an integrated AN / UP NF (ANUP), which optionally provides VPN functionality. These techniques fully leverage IETF / wired technologies and provide integrated services for wired / fixed and wireless / mobile customers. In at least some examples, these techniques may not require changes in the control plane, although the control plane can be optimized for the compressed user plane.

[0056] The following subsections describe how the new architecture supports some of the existing features.

[0057] Switch

[0058] For IP PDU sessions, if session continuity is not an issue (e.g., the application is able to handle changing addresses), the UE can be assigned a different IP address each time it is anchored to a different UPF. No special handling is required in this case.

[0059] If necessary, a persistent IP address can be assigned even when the UE moves from one ANUP to another. To handle mobility and handover, each ANUP advertises host routes for UEs anchored to it. When a UE leaves an ANUP, that ANUP revokes the host route.

[0060] For example, if a UE moves from ANUP2 to ANUP1, ANUP2 initially advertises the UE's address. After the UE moves to ANUP1, ANUP1 advertises the UE's address and ANUP2 withdraws the route. Traffic from the DN to the UE (within the DN) is sent to ANUP1, which then routes it to the UE. There may be in-flight traffic (within the DN) destined for ANUP2. Once a host route advertised by ANUP1 becomes an active route on that node, any node in the path (including ANUP2 itself) will redirect traffic to ANUP1.

[0061] ANUPs can retain host routes advertised by other ANUPs. In this case, UE-to-UE traffic will take the short ANUP-ANUP path. Alternatively, an ANUP can maintain only its advertised host routes and the default route to the central router on the DN. In this way, UE-to-UE / Internet traffic can pass through the central router. Note that from a traffic path perspective, this is similar to the 5G central UPF scenario (the central UPF corresponds to the central router in the new user plane architecture), except that in the 5G scenario, traffic is sent to / from the central UPF via the N3 tunnel, while in the new architecture, traffic is routed to / from the central router (in a VPN). Furthermore, although the central router needs to maintain all host routes, the number of host routes can be directly comparable to the number of per-session states (PDR / FAR) maintained by the 5G UPF.

[0062] For the same reason, maintaining host routing within a DN is similar to maintaining per-session state in the 5G context. Even if the DN is the "Internet" (e.g., the UE is a "consumer" UE rather than a "commercial" UE accessing a company intranet), host routing is not advertised to the public Internet. Instead, host routing is restricted to the internal portion of the operator's "Internet access network".

[0063] Note that the above content of the IP PDU session in the new architecture is very similar to that of the Ethernet PDU session, even in 5G (switching the individual-based “host” MAC address, and the MAC address will not change when the UE moves from one ANUP to another).

[0064] Legitimate interception, accounting, etc.

[0065] These features are integrated into ANUP and can continue to work similarly with 5G systems.

[0066] Per-flow QoS

[0067] If traffic to / from a UE originates from / is destined for another UE on the same anchored ANUP, then all QoS-related processing only needs to involve that ANUP.

[0068] Otherwise, traffic needs to pass through another ANUP or central router on the underlying VPN tunnel.

[0069] • Perform QoS marking within the VPN tunnel encapsulation. For comparison, in the case of N3 tunnel transmission, QoS marking is performed in both the IP / UDP header and the GTP header.

[0070] • Flow shaping can be performed at two levels:

[0071] a. Conducted by ANUP on the radio link

[0072] b. This is performed by the central hub on the central hub → ANUP tunnel to prevent the ANUP from being overwhelmed by traffic from the Internet. This can be done at the per-session (host routing) level, just as it can be done at the per-session (N3 tunnel) level in the case of 5G. QoS parameters (such as those learned via N4 signaling) can be advertised by the PSA UPF along with host routes, thus requiring no modifications or additional requirements to the AMF / PCF / other core functions.

[0073] While it may not be necessary to perform this on the ANUP→ANUP / central tunnel, traffic shaping can also be done by the source ANUP at the per-session (host routing) level.

[0074] Security

[0075] Encryption between the UE and ANUP can be similar to or the same as encryption between the UE and gNodeB in 5G. Previous encryption between the gNB and UPF is no longer needed, as they are now a single entity. ANUP-ANUP / central encryption can be performed as in existing VPN deployments (although there are no security requirements at the VPN level if the transport infrastructure is already secure).

[0076] There are situations where separate AN and UP functionalities may be desired. For example, home-roaming (where a subscriber accesses the visited network via its RAN but receives services provided by its home network) requires separate HPLMN UPF and VPLMN AN. In another example, an MNO (Mobile Network Operator) may want to deploy a UPF for the access network cluster near certain locations. Furthermore, an MNO may support a VMNO (Virtual Mobile Network Operator) that has its own UP functionality but utilizes the access network hosted by the MNO. In these examples, tunneling is required between the AN and UP. In such cases, tunneling can be achieved via the pseudowire technique of IEFT, as described below.

[0077] Home Roaming

[0078] Regarding roaming, local exit-based (LBO) roaming can be naturally supported in the new architecture because the AN and UP functions are retained in the visitor network. However, for home-roaming in 5G, the N3 tunnel from the visitor network (VPLMN) extends to N9 and terminates at the UPF in the home network (HPLMN), as... Figure 4 As shown.

[0079] In the architecture implemented and deployed according to the technology described herein, although the UPF can terminate the PDU session of a non-roaming UE, the UPF cannot terminate the PDU session of a roaming UE with a home route—the PDU session needs to be extended to the UPF in the Home Public Land Mobile Network (HPLMN). This can be done via a mature pseudowire technique as defined in the IETF, as explained below. Pseudowires are described in Request for Comments 3985, “Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture,” issued by the Internet Engineering Task Force in March 2005, the entirety of which is incorporated herein by reference.

[0080] Comments (RFC) 3985 description:

[0081] This paper describes an architecture for pseudowire emulation of edge-to-edge (PWE3) that supports [RFC3916]. It discusses emulation of services such as Frame Relay, ATM, Ethernet, TDM, and SONET / SDH over packet-switched networks (PSN) using IP or MPLS. It presents an architectural framework for pseudowire (PW), defines the terminology, and specifies the various protocol elements and their functions.

[0082] …

[0083] PW provides the following features to simulate the behavior and characteristics of native services.

[0084] ο Encapsulate service-specific PDUs or circuit data that reaches PE-bound ports (logical or physical).

[0085] Transmit encapsulated data through the PSN tunnel.

[0086] The establishment of a PW includes the exchange and / or distribution of PW identifiers used by PSN tunnel endpoints.

[0087] o In the signaling, timing, sequencing or other aspects of PW's boundary management services.

[0088] o Service-specific status and alarm management.

[0089] …

[0090] The payload is divided into the following general types of raw data units:

[0091] οgroup

[0092] οCell

[0093] bit stream

[0094] Structured bitstream

[0095] Specific service types exist within these general types:

[0096]

[0097] When applied to extend a home-roaming PDU session to the HPLMN, the payload type is "Packet"—IP packets or Ethernet frames for IP or Ethernet PDU sessions (i.e., the layer above the SDAP layer between the UE and the local gNodeB). In the case of unstructured PDU session types, the PW payload type will be "Bitstream".

[0098] Figure 5 A network reference model for pseudo-wire emulation is depicted according to RFC 3985. This model can be mapped to a mobile user plane architecture implemented and deployed according to the techniques described in this disclosure. Figure 6 An example protocol stack for home-roaming according to the techniques of this disclosure is depicted. PE2 and PE3 are used for DN VPN, and PEa and PEb are used for PW for roaming purposes. In this example description, UE1 is roaming while UE2 is not. UE1 is connected to ANUP 338 of the visitor network, represented as a VPLMN, where pseudowires are used to connect to ANPU 340 of UE1's home network, represented as an HPLMN.

[0099] The following helps explain the mapping to the mobile user plane architecture:

[0100] · Figure 5 Customer Edge 1 (CE1) in the PLMN corresponds to the roaming UE, and Provider Edge 1 (PE1) / AN corresponds to ANUP 338 in the visited PLMN (although it does not terminate the PDU session but extends it to the PW).

[0101] The radio link between CE1 / UE1 and PE1 / ANUP 338 is the AC in the PW architecture. The PDU session is an emulation service. The pseudowire corresponds to the N3 / N9 tunnel in 5G. The PSN tunnel corresponds to the UDP tunnel for transmitting N3 / N9 in 5G.

[0102] • Provider Edge 2 (PE2) and Customer Edge 2 (CE2) together correspond to ANUP340 in the HPLMN of the new architecture. It is evident that PE2 provides AN functionality (PW corresponds to the radio link), and CE2 provides UPF functionality.

[0103] PE1 receives PDU packets from the UE (after decapsulating the SDAP stack), which are treated as PW payloads and sent to PE2 via the PW. PE2 decapsulates the PW and exposes the PDU (in a manner similar to how the gNodeB decapsulates the SDAP stack), which is then terminated by CE2 (although, according to the techniques of this disclosure, PE2 and CE2 are integrated into a single ANUP).

[0104] In a 5G home routing roaming architecture, there exists a pair of I-UPF-N3 tunnels between two PLMNs that do not extend directly from the AN of the VPLMN to the UPF of the HPLMN. A similar concept exists in VPN technology—the I-UPF can function similarly to a pair of ASBRs providing option-B inter-AS VPN services.

[0105] Alternatively, in some examples, N3 / N9 tunneling can still be used instead (although one of the motivations for this new architecture is to remove N3 / N9 tunneling, so this is only an alternative implementation in cases where N3 / N9 tunneling must be used).

[0106] Virtual Mobile Network Operator (VMNO) and UP for AN Cluster

[0107] Operators may not be able (or may not want to) distribute UPFs entirely to access nodes. Instead, they can deploy more centralized UPFs for clusters of nearby access nodes.

[0108] The operator can support a "full VMNO," lacking only its own radio network. In this case, a tunneling transmission from the AN / ANUP to the UP / UPF of the Mobile Virtual Network Operator (MVNO) is also required. Similar to roaming scenarios, pseudowires (or even N3 / N9) can be used for these scenarios as described in the preceding paragraphs.

[0109] Figure 7 This is a block diagram illustrating details of an example of a computing device operating according to one or more techniques disclosed herein. Figure 7 Specific examples of a server or other computing device 1000 may be shown, which includes one or more processors 1002 for performing one or more of the following described herein: Access Network User Plane Function (ANUP) 1024, Applications 191A-191N, other Applications 1022, or any other system, application, node software, or module. Other examples of the computing device 1000 may be used in other instances. Although for illustrative purposes... Figure 7The device is shown as a standalone computing device 1000, but computing device 1000 can be any component or system including one or more processors or other suitable computing environments for executing software instructions, and does not necessarily need to include, for example, a separate computing device 1000. Figure 7 One or more components shown (e.g., communication unit 1006); and in some examples, components such as storage devices 1008 may not be co-located with other components or may not be in a different chassis. Figure 7 As shown in a specific example, computing device 1000 includes: one or more processors 1002, one or more input devices 1004, one or more communication units 1006, one or more output devices 1012, one or more storage devices 1008, and a user interface (UI) device 1010. In one example, computing device 1000 also includes one or more applications 1022 and an operating system 1016 executable by computing device 1000. Each of components 1002, 1004, 1006, 1008, 1010, and 1012 is (physically, communicatively, and / or operatively) coupled for inter-component communication. In some examples, communication channel 1014 may include: a system bus, a network connection, an inter-process communication data structure, a message bus, or any other method for transmitting data. As an example, components 1002, 1004, 1006, 1008, 1010, and 1012 may be coupled by one or more communication channels 1014.

[0110] In one example, processor 1002 is configured to implement functional and / or processing instructions for execution within computing device 1000. For example, processor 1002 may be a processing circuitry means capable of processing instructions stored in storage device 1008. Examples of processor 1002 may include any one or more of the following: a microprocessor, a controller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or an equivalent discrete or integrated logic circuitry means.

[0111] One or more storage devices 1008 may be configured to store information within computing device 1000 during operation. In some examples, storage device 1008 is described as a computer-readable storage medium. In some examples, storage device 1008 is temporary memory, meaning that the primary purpose of storage device 1008 is not long-term storage. In some examples, storage device 1008 is described as volatile memory, meaning that storage device 1008 does not retain its stored contents when the computer is shut down. Examples of volatile memory include random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), and other forms of volatile memory known in the art. In some examples, storage device 1008 is used to store program instructions for execution by processor 1002. In one example, storage device 1008 is used by software or applications running on computing device 1000 to temporarily store information during program execution.

[0112] In some examples, storage device 1008 also includes one or more computer-readable storage media. Storage device 1008 can be configured to store a larger amount of information than volatile memory. Storage device 1008 can also be configured for long-term storage of information. In some examples, storage device 1008 includes non-volatile storage elements. Examples of such non-volatile storage elements include magnetic hard disks, optical disks, floppy disks, flash memory, or electrically programmable memory (EPROM) or electrically erasable programmable memory (EEPROM).

[0113] In some examples, computing device 1000 also includes one or more communication units 1006. In one example, computing device 1000 uses communication unit 1006 to communicate with external devices via one or more networks, such as one or more wired / wireless / mobile networks. Communication unit 1006 may include a network interface card such as an Ethernet card, an optical transceiver, a radio frequency transceiver, or any other type of device capable of transmitting and receiving information. In some examples, computing device 1000 uses communication unit 1006 to communicate with external devices.

[0114] In one example, computing device 1000 also includes one or more user interface devices 1010. In some examples, user interface devices 1010 are configured to receive input from a user via haptic, audio, or video feedback. Examples of the multiple user interface devices 1010 include presence-sensitive displays, mice, keyboards, voice response systems, cameras, microphones, or any other type of device for detecting commands from the user. In some examples, presence-sensitive displays include touch-sensitive screens.

[0115] One or more output devices 1012 may also be included in the computing device 1000. In some examples, the output device 1012 is configured to provide output to a user using tactile, audio, or video stimuli. In one example, the output device 1012 includes a presence-sensitive display, a sound card, a video graphics adapter card, or any other type of device for converting signals into an appropriate form that is understandable to humans or machines. Other examples of the output device 1012 include a speaker, a cathode ray tube (CRT) monitor, a liquid crystal display (LCD), or any other type of device that can produce understandable output to a user.

[0116] Computing device 1000 may include operating system 1016. In some examples, operating system 1016 controls the operation of components of computing device 1000. For example, in one example, operating system 1016 facilitates communication between one or more applications 1022, including ANUP 302, and processor 1002, communication unit 1006, storage device 1008, input device 1004, user interface device 1010, and output device 1012.

[0117] Application 1022 may also include program instructions and / or data executable by computing device 1000. Example application 1022 executable by computing device 1000 may include applications and / or other software that implement the above-described capabilities. For example, application 1022 may include applications 191A-191N to implement services.

[0118] Access network user plane function 1024 is a network function that implements both the 3GPP access network protocol layer stack (e.g., xG-AN protocol layer) and the IETF network stack, supporting the PDU layer, and performs routing / handover between the PDU layer and the IETF stack. In some cases, the PDU layer can be IPv4 / IPv6 or Ethernet. For example, access network user plane function 1024 can be implemented and deployed as a virtual machine, bare metal server application, process, or container. Thus, access network user plane function 1024 can be a virtualized network function (VNF) or a cloud-native / containerized network function (CNF) deployed to computing device 1000.

[0119] Computing device 1000 may represent any example instance of an ANUP device or system described in this disclosure, such as ANUP 302, ANUP 320, or ANUP 340. Depending on the context in which the term is used in this disclosure, "access network user plane function" may refer to a software-implemented network function or a hardware computing device, system, appliance, or other system that implements the access network user plane function. This usage will be understood by those skilled in the art of mobile networks. The phrase "access network user plane" may be used herein as an abbreviation or acronym for access network user plane function.

[0120] The techniques described in this disclosure can be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, various aspects of the described techniques can be implemented within one or more programmable processors, including: one or more microprocessors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuit devices, and any combination of such components. The terms "processor" or "processing circuit device" can generally refer to any of the aforementioned logic circuit devices, alone or in combination with other logic circuit devices or any other equivalent circuit devices. Control units, including hardware, can also execute one or more of the techniques of this disclosure.

[0121] Such hardware, software, and firmware can be implemented within the same device or in separate devices to support the various operations and functions described in this invention. Furthermore, any of the described units, modules, or components can be implemented together or separately as discrete but interoperable logical devices. Describing different features as modules or units is intended to highlight different functional aspects and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Rather, the functionality associated with one or more modules or units can be performed by separate hardware or software components, or integrated within common or separate hardware or software components.

[0122] The techniques described in this invention can also be embodied in or encoded in a computer-readable medium (such as a computer-readable storage medium) containing instructions. Instructions embedded in or encoded in a computer-readable medium can cause a programmable processor or other processor to perform the methods, for example, when executing the instructions. Computer-readable media can include non-transient computer-readable storage media and transient communication media. Tangible and non-transient computer-readable storage media can include: random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, hard disk, CD-ROM, floppy disk, magnetic tape cassette, magnetic media, optical media, or other computer-readable storage media. The term "computer-readable storage medium" refers to a physical storage medium, not a signal, carrier, or transient medium.

Claims

1. An Access Network User Plane Function (ANUP) for a mobile network, the ANUP including processing circuitry and configured to: Execute access network protocols to establish a connection with user equipment (UE); An interface with the data network is implemented based on session data received from the control plane function of the mobile core network for the mobile network. A common interface with the mobile core network is implemented, wherein the common interface provides a combination of N2 and N4 interfaces; as well as Routing or exchanging packets between the connection with the UE and the interface with the data network.

2. The ANUP according to claim 1, wherein the ANUP does not implement the N3 interface.

3. The ANUP according to claim 1, wherein the control plane function includes one of Access Mobility Management Function (AMF) or Session Management Function (SMF).

4. The ANUP according to any one of claims 1 to 3, wherein the access network protocol includes one of the following: Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Service Data Adaptation Protocol (SDAP).

5. The ANUP according to any one of claims 1 to 3, The access network protocol is used at the access network protocol layer, which supports the Protocol Data Unit (PDU) layer between the connected UE and the ANUP. In order to route or exchange packets between the connection with the UE and the interface with the data network, the ANUP is configured to route IP packets, exchange Ethernet frames, or relay unstructured PDU data.

6. The ANUP according to any one of claims 1 to 3, wherein a single server includes the processing circuitry.

7. The ANUP according to any one of claims 1 to 3, wherein the ANUP is configured to advertise host routes to the data network, the host routes including Internet Protocol addresses for the connected UEs.

8. The ANUP of claim 7, wherein the data network is implemented as an Internet Protocol Virtual Private Network (IP-VPN) or an Ethernet VPN, wherein the ANUP is configured as a customer edge (CE) device connected to a provider edge (PE) device, or integrated into the PE device of the IP-VPN or Ethernet VPN.

9. The ANUP of claim 8, wherein the ANUP is configured to use segmented routing to implement tunneling for the IP-VPN or Ethernet VPN.

10. The ANUP according to any one of claims 1 to 3, wherein the ANUP is configured to implement a pseudowire across the transport network for transmitting packet data traffic in cases using separate access network functions and user plane functions.

11. The ANUP of claim 10, wherein the ANUP is configured to implement a pseudowire across a transport network between a visited public land mobile network (VPLMN) and a home public land mobile network (HPLMN) to transmit packet data traffic received from a UE connected to the VPLMN to the HPLMN.

12. The ANUP of claim 10, wherein the ANUP is configured to implement a pseudowire across a transport network to transmit packet data traffic to the network of a mobile virtual network operator.

13. The ANUP of claim 10, wherein the ANUP is configured to implement a pseudowire across transport networks to transmit packet data traffic to a UPF serving multiple access networks.

14. A mobile network system, comprising: Mobile core network, including control plane functions; and Access Network User Plane Function (ANUP) for mobile networks, wherein the ANUP is configured as follows: Execute access network protocols to establish a connection with user equipment (UE); An interface with the data network is implemented based on session data received from the control plane function of the mobile core network; A common interface with the mobile core network is implemented, wherein the common interface provides a combination of N2 and N4 interfaces; as well as Routing or exchanging packets between the connection with the UE and the interface with the data network.

15. A computer networking method, comprising: Access network protocols are executed by the Access Network User Plane Function (ANUP) for mobile networks to establish connections with user equipment (UE). The ANUP implements an interface with the data network based on session data received from the control plane function of the mobile core network for the mobile network. A common interface with the mobile core network is implemented, wherein the common interface provides a combination of N2 and N4 interfaces; as well as The ANUP routes or exchanges packets between the connection with the UE and the interface with the data network.

16. The computer networking method according to claim 15, wherein the ANUP does not implement the N3 interface.

17. The computer networking method according to claim 15, wherein the access network protocol is used for the access network protocol layer, the access network protocol layer supports the Protocol Data Unit (PDU) layer between the connected UE and the ANUP, and In order to route or exchange packets between the connection with the UE and the interface with the data network, the ANUP is configured to route IP packets, exchange Ethernet frames, or relay unstructured PDU data.

18. The computer networking method according to any one of claims 15 to 17, wherein the ANUP is a first ANUP, the method further comprising: The first ANUP announces the host route for the newly connected UE to the first ANUP to the data network; The second ANUP revokes the host route for the UE that was previously connected to the second ANUP from the data network; When the UE disconnects from the second ANUP and reconnects to the first ANUP, the nodes in the data network use active host routing to direct traffic for the UE to the first ANUP.

19. The computer networking method of claim 15, wherein the data network is implemented as an Internet Protocol Virtual Private Network (IP-VPN) or an Ethernet VPN, wherein the ANUP is configured as a customer edge device (CE) connected to a provider edge (PE) device, or integrated into the PE device of the IP-VPN or Ethernet VPN.

20. The computer networking method of claim 19, further comprising: The ANUP uses segmented routing to achieve tunneling for the IP-VPN or the Ethernet VPN.

21. A computer-readable storage medium encoded with instructions for causing one or more programmable processors to perform the method according to any one of claims 15 to 20.

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