Connection recovery procedure for UE in EDRX and RRC inactive state for MT data

Abstract

The present invention describes techniques, systems and devices for supporting user equipment (UE) in extended discontinuous reception mode. The techniques performed by a radio access network (RAN) include: managing UE in extended discontinuous reception mode and in an inactive state; sending a notification message to an access and mobility management function (AMF), the message including buffer support information for a user plane function (UPF) to buffer data; receiving a notification request message from the AMF, the notification request message including a request to obtain information about the reachability of the UE; sending a notification response message to control when the UPF provides downlink data to the RAN for transmission to the UE; performing a connection recovery procedure with the UE to cause the UE to switch from an inactive state to a connected state; receiving downlink data; and transmitting downlink data to the UE.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 828,344, entitled “CONNECTION RESUME PROCEDURE FORUE IN EDRX AND RRC INACTIVE STATE FOR MT DATA,” filed on April 2, 2019. The entirety of the above-described patent application is incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to signaling in wireless communication systems. Background Art

[0004] The use of wireless communication systems is growing rapidly. In addition, wireless communication technology has evolved from voice-only communications to also include the transmission of data (such as the Internet and multimedia content) to various devices. In order to accommodate the increasing number of devices that communicate, many wireless communication systems share available communication channel resources between devices. Internet of Things (IoT) devices are also growing in use and can coexist with user devices in various wireless communication systems such as cellular networks.

[0005] Base stations, such as nodes of a radio access network (RAN), can communicate wirelessly with wireless devices, such as user equipment (UE). Downlink (DL) transmissions refer to communications from a base station to a wireless device. Uplink (UL) transmissions refer to communications from a wireless device to another device, such as a base station. A base station can transmit control signaling in order to control wireless devices operating within its network. Summary of the invention

[0006] The present invention describes techniques, systems and devices for supporting user equipment (UE) in extended discontinuous reception mode. The techniques include: managing the UE in extended discontinuous reception mode and in an inactive state by the RAN; sending a notification message by the RAN to an access and mobility management function (AMF), the notification message including information causing a user plane function (UPF) to buffer data for the UE; receiving a notification request message by the RAN from the AMF, the notification request message including a request for obtaining information about the reachability of the UE; sending a notification response message by the RAN to control when the UPF provides downlink data to the RAN for transmission to the UE; performing a connection recovery procedure with the UE to cause the UE to switch from an inactive state to a connected state; receiving downlink data by the RAN from the UPF; and transmitting downlink data to the UE. Other specific implementations include corresponding systems, devices and computer programs for performing the actions of the method defined by instructions encoded on a computer-readable storage device.

[0007] These and other implementations may include one or more of the following features. The RAN may be configured to determine a next paging time for the UE based on the extended discontinuous reception mode. The implementation may include generating expected UE reachability information based on the next paging time. The notification response message may include the expected UE reachability information. The UPF may be configured to forward downlink data based on the expected UE reachability information.

[0008] Specific implementations may include the RAN transmitting a page to the UE based on the next paging time to trigger the connection recovery process. Sending the notification response message may be based on the completion of the connection recovery process. The notification response message may include a notification that the UE is ready to receive data. The UPF may be configured to forward downlink data upon receiving the notification that the UE is ready to receive data.

[0009] In some implementations, the notification request message is triggered by receiving data for the UE at the UPF. In some implementations, the UE is associated with a first node of the RAN before entering a sleep cycle according to the extended discontinuous reception mode. Performing a connection recovery procedure may include operating a second node of the RAN to perform a connection recovery procedure with the UE. The UPF may be configured to forward the downlink data to the second node.

[0010] A RAN in a wireless communication system may include: one or more processors; a circuit configured to communicate with a device such as a UE; a circuit configured to communicate with a device providing an AMF; and a memory storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations. These operations may include: managing a UE in an extended discontinuous reception mode and an inactive state; sending a notification message to the AMF, the notification message including buffer support information for the UPF to buffer data for the UE; receiving a notification request message from the AMF, the notification request message including a request to obtain information about the reachability of the UE; sending a notification response message to control when the UPF provides downlink data to the RAN for transmission to the UE; performing a connection recovery procedure with the UE to cause the UE to switch from the inactive state to the connected state; receiving downlink data from the UPF; and transmitting downlink data to the UE.

[0011] These specific implementations and other specific implementations may include one or more of the following features. These operations may include determining the next paging time of the UE according to the extended discontinuous reception mode. These operations may include generating expected UE reachability information based on the next paging time. The notification response message may include the expected UE reachability information. The UPF may be configured to forward downlink data according to the expected UE reachability information. These operations may include transmitting a paging to the UE by the RAN based on the next paging time to trigger a connection recovery process. Sending the notification response message may be based on the completion of the connection recovery process. The notification response message may include a notification that the UE is ready to receive data. The UPF may be configured to forward downlink data upon receiving a notification that the UE is ready to receive data. The notification request message may be triggered by receiving data for the UE at the UPF. In some specific implementations, the UE is associated with a first node of the RAN before entering a sleep cycle according to the extended discontinuous reception mode, and performing a connection recovery process may include causing a second node of the RAN to perform a connection recovery process with the UE. The UPF may be configured to forward downlink data to the second node.

[0012] The details of one or more specific implementations are set forth in the drawings and description below. Other features and advantages will be apparent from the detailed description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 An example of a wireless communication system is illustrated.

[0014] Figure 2 An exemplary architecture of a system including a core network is illustrated.

[0015] Figure 3 Another exemplary architecture of a system including a core network is illustrated.

[0016] Figure 4 An example of infrastructure equipment is illustrated.

[0017] Figure 5 An example of a platform or device is illustrated.

[0018] Figure 6 Exemplary components of baseband circuitry and radio front-end circuitry are illustrated.

[0019] Figure 7 Exemplary components of a cellular communications circuit are illustrated.

[0020] Figure 8 Example protocol functions that may be implemented in a wireless communication system are illustrated.

[0021] Fig. 9 An example of a computer system is illustrated.

[0022] Fig.10 An example of a network triggered communication process for mobile terminated data is shown.

[0023] Fig.11 Another example of a network triggered communication process for mobile terminated data is shown.

[0024] Fig.12 An example of a connection recovery procedure is shown.

[0025] Fig.13 A flow chart illustrating an example of a process associated with buffering downlink data and delivering the downlink data to a UE.

[0026] Like reference symbols in the various drawings indicate like elements. DETAILED DESCRIPTION

[0027] In many wireless communication systems, including Long Term Evolution (LTE) and Fifth Generation New Radio (5G NR) cellular networks, a user equipment (UE) may need to transmit small amounts of data to a base station (BS) within the network. For example, in the Cellular Internet of Things (CIoT), a sensor device equipped with a communication device such as a user equipment (UE) may acquire sensor readings and then transmit the readings or a batch of readings to the BS. Other examples include tracking devices for mobile originated (MO) and mobile terminated (MT) use cases that report location via the BS. The present disclosure describes, among other things, signaling mechanisms to support frequent small data transmissions without path switching between different base stations.

[0028] Figure 1 An example of a wireless communication system 100 is illustrated. For convenience and not limitation, the exemplary system 100 is described in the context of LTE and 5G NR communication standards defined by the 3rd Generation Partnership Project (3GPP) technical specifications. However, other types of wireless standards are possible.

[0029] System 100 includes UE 101a and UE 101b (collectively referred to as "UE 101"). In this example, UE 101 is shown as a smartphone (eg, a handheld, touch-screen mobile computing device that can connect to one or more cellular networks). In other examples, any of the UEs 101 may include other mobile or non-mobile computing devices, such as consumer electronic devices, cellular phones, smart phones, feature phones, tablet computers, wearable computer devices, personal digital assistants (PDAs), pagers, wireless handheld devices, desktop computers, laptop computers, in-vehicle infotainment (IVI), in-car entertainment (ICE) devices, instrument clusters (ICs), heads-up display (HUD) devices, on-board diagnostic (OBD) devices, on-board mobile equipment (DME), mobile data terminals (MDTs), electronic engine management systems (EEMS), electronic / engine control units (ECUs), electronic / engine control modules (ECMs), embedded systems, microcontrollers, control modules, engine management systems (EMS), networked or “smart” appliances, machine type communication (MTC) devices, machine-to-machine (M2M) devices, Internet of Things (IoT) devices, or combinations thereof, etc.

[0030] In some implementations, any of the UEs 101 may be an IoT UE, which may include a network access layer designed for low-power IoT applications that utilize short-term UE connections. The IoT UE may utilize technologies such as M2M or MTC to exchange data with an MTC server or device using, for example, a public land mobile network (PLMN), a short-range service (ProSe), a device-to-device (D2D) communication, a sensor network, an IoT network, or a combination thereof. The M2M or MTC data exchange may be a machine-initiated data exchange. The IoT network describes interconnected IoT UEs that may include uniquely identifiable embedded computing devices (within the Internet infrastructure) with short-lived connections. The IoT UE may execute background applications (e.g., keep-alive messages or status updates) to facilitate connectivity to the IoT network. In some implementations, one or more of the UEs 110 may be configured for discontinuous reception mode (DRX) communication. In some implementations, one or more of the UEs 110 may be configured for extended DRX (eDRX) communication.

[0031] The UE 101 may be configured to connect (e.g., be communicatively coupled) to a radio access network (RAN) 110. In some implementations, the RAN 110 may be a next generation RAN (NG-RAN), an evolved UMTS terrestrial radio access network (E-UTRAN), or a legacy RAN, such as a UMTS terrestrial radio access network (UTRAN) or a GSM EDGE radio access network (GERAN). As used herein, the term "NG-RAN" may refer to the RAN 110 operating in a 5G NR system 100, while the term "E-UTRAN" may refer to the RAN 110 operating in an LTE or 4G system 100.

[0032] To connect to the RAN 110, the UE 101 utilizes connections (or channels) 103 and 104, respectively, each of which may include a physical communication interface or layer, as described below. In this example, connections 103 and 104 are shown as air interfaces to achieve communication coupling, and may be consistent with a cellular communication protocol, such as a global system for mobile communications (GSM) protocol, a code division multiple access (CDMA) network protocol, a push-to-talk (PTT) protocol, a cellular PTT (POC) protocol, a universal mobile telecommunications system (UMTS) protocol, a 3GPP LTE protocol, a 5G NR protocol, or a combination thereof, as well as other communication protocols.

[0033] UE 101b is shown configured to access access point (AP) 106 (also referred to as "WLAN node 106", "WLAN 106", "WLAN termination 106", "WT 106", etc.) using connection 107. Connection 107 may include a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, where AP 106 would include a Wireless Fidelity (Wi-Fi) router. In this example, AP 106 is shown connected to the Internet and not to the core network of the wireless system, as described in further detail below.

[0034] The RAN 110 includes one or more nodes such as RAN nodes 111a and 111b (collectively referred to as "RAN nodes 111") that enable connections 103 and 104. As used herein, the terms "access node", "access point", etc. may describe equipment that provides radio baseband functions for data or voice connections or both between a network and one or more users. These access nodes may be referred to as base stations (BS), gNodeBs, gNBs, eNodeBs, eNBs, NodeBs, RAN nodes, road side units (RSUs), transmit receive points (TRxPs or TRPs), etc., and may include ground stations (e.g., terrestrial access points) or satellite stations that provide coverage within a geographic area (e.g., a cell), etc. As used herein, the term "NG-RAN node" may refer to a RAN node 111 (e.g., a gNB) operating in a 5G NR system 100, while the term "E-UTRAN node" may refer to a RAN node 111 (e.g., an eNB) operating in an LTE or 4G system 100. In some implementations, the RAN node 111 may be implemented as one or more of a dedicated physical device such as a macrocell base station, or a low power (LP) base station for providing a femtocell, picocell, or other similar cell with a smaller coverage area, smaller user capacity, or higher bandwidth than a macrocell.

[0035] In some implementations, some or all of the RAN nodes 111 may be implemented as one or more software entities running on a server computer as part of a virtual network that may be referred to as a cloud RAN (CRAN) and / or a virtual baseband unit pool (vBBUP). The CRAN or vBBUP may implement a RAN functional split, such as a packet data convergence protocol (PDCP) split, where the radio resource control (RRC) and PDCP layers are operated by the CRAN / vBBUP, and other layer 2 (e.g., data link layer) protocol entities are operated by individual RAN nodes 111; a medium access control (MAC) / physical layer (PHY) split, where the RRC, PDCP, MAC, and radio link control (RLC) layers are operated by the CRAN / vBBUP, and the PHY layer is operated by individual RAN nodes 111; or a "lower PHY" split, where the RRC, PDCP, RLC, and MAC layers and the upper portion of the PHY layer are operated by the CRAN / vBBUP, and the lower portion of the PHY layer is operated by individual RAN nodes 111. The virtualization framework allows idle processor cores of the RAN node 111 to execute, for example, other virtualized applications. In some implementations, a single RAN node 111 may represent a single virtualized application using each F1 interface ( Figure 1 ) are connected to the gNB Central Unit (CU). In some implementations, the gNB-DU may include one or more remote radio heads or RFEMs (see, e.g., Figure 4 ), and the gNB-CU may be operated by a server (not shown) located in the RAN 110 or by a server pool in a manner similar to the CRAN / vBBUP. In addition or alternatively, one or more of the RAN nodes 111 may be a next generation eNB (ng-eNB), including a RAN node that provides E-UTRA user plane and control plane protocol terminals to the UE 101 and is connected to a 5G core network (e.g., the core network 120) using a next generation interface.

[0036] In a vehicle-to-everything (V2X) scenario, one or more of the RAN nodes 111 may be or act as an RSU. The term "roadside unit" or "RSU" refers to any traffic infrastructure entity used for V2X communication. The RSU may be implemented in or by a suitable RAN node or a stationary (or relatively stationary) UE, wherein an RSU implemented in or by a UE may be referred to as a "UE-type RSU", an RSU implemented in or by an eNB may be referred to as an "eNB-type RSU", an RSU implemented in or by a gNB may be referred to as a "gNB-type RSU", and so on. In some specific implementations, the RSU is a computing device coupled to a radio frequency circuit located on the road side that provides connectivity support to a passing vehicle UE 101 (vUE 101). The RSU may also include internal data storage circuitry for storing intersection map geometry, traffic statistics, media, and applications or other software for sensing and controlling ongoing vehicle and pedestrian traffic. The RSU may operate on the 5.9 GHz Direct Short Range Communications (DSRC) band to provide extremely low latency communications required for high-speed events, such as collision avoidance, traffic warnings, and the like. In addition or alternatively, the RSU may operate on the cellular V2X band to provide the aforementioned low latency communications as well as other cellular communications services. In addition or alternatively, the RSU may operate as a Wi-Fi hotspot (2.4 GHz band) or provide connectivity to one or more cellular networks to provide uplink and downlink communications, or both. Some or all of the computing device and the RSU's RF circuitry may be packaged in a weather-resistant enclosure suitable for outdoor installation, and may include a network interface controller to provide a wired connection (e.g., Ethernet) to a traffic signal controller or a backhaul network, or both.

[0037] Any of the RAN nodes 111 may serve as a termination point for the air interface protocol and may be the first point of contact for the UE 101. In some implementations, any of the RAN nodes 111 may perform various logical functions of the RAN 110, including but not limited to functions of a radio network controller (RNC), such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management.

[0038] In some implementations, multiple UEs 101 may be configured to communicate with each other or any of RAN nodes 111 over a multi-carrier communication channel using orthogonal frequency division multiplexing (OFDM) communication signals according to various communication techniques, such as, but not limited to, OFDMA communication techniques (e.g., for downlink communications) or SC-FDMA communication techniques (e.g., for uplink communications), although the scope of the techniques described herein is not limited in this respect. The OFDM signal may include multiple orthogonal subcarriers.

[0039] The RAN node 111 may transmit to the UE 101 via various channels. Various examples of downlink communication channels include a physical broadcast channel (PBCH), a physical downlink control channel (PDCCH), and a physical downlink shared channel (PDSCH). Other types of downlink channels are possible. The UE 101 may transmit to the RAN node 111 via various channels. Various examples of uplink communication channels include a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and a physical random access channel (PRACH). Other types of uplink channels are possible.

[0040] In some specific implementations, a downlink resource grid may be used for downlink transmissions from any of the RAN nodes 111 to the UE 101, while uplink transmissions may utilize similar techniques. The grid may be a time-frequency grid, referred to as a resource grid or a time-frequency resource grid, which is a physical resource in the downlink in each time slot. For OFDM systems, such a time-frequency plane representation is a common practice, which makes wireless resource allocation intuitive. Each column and each row of the resource grid corresponds to an OFDM symbol and an OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to a time slot in a radio frame. The smallest time-frequency unit in the resource grid is represented as a resource element. Each resource grid may include multiple resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block may include a set of resource elements. In the frequency domain, this may represent the minimum amount of resources that can currently be allocated. Such resource blocks are used to transmit several different physical downlink channels.

[0041] The PDSCH carries user data and higher layer signaling to multiple UEs 101. The PDCCH carries, among other information, information about the transport format and resource allocation related to the PDSCH channel. It may also inform the UE 101 about the transport format, resource allocation, and hybrid automatic repeat request (HARQ) information related to the uplink shared channel. Downlink scheduling (e.g., allocating control and shared channel resource blocks to UE 101b within a cell) may be performed at any of the RAN nodes 111 based on channel quality information fed back from any of the UEs 101. Downlink resource allocation information may be sent on the PDCCH for (e.g., allocated to) each of the UEs 101.

[0042] PDCCH uses control channel elements (CCE) to transmit control information. Before being mapped to resource elements, the PDCCH complex-valued symbols can first be organized into quadruplets, which can then be arranged using a sub-block interleaver for rate matching. In some implementations, one or more of these CCEs can be used to transmit each PDCCH, where each CCE can correspond to four sets of nine physical resource elements, collectively referred to as resource element groups (REGs). Four quadrature phase shift keying (QPSK) symbols can be mapped to each REG. Depending on the size of the downlink control information (DCI) and channel conditions, one or more CCEs can be used to transmit the PDCCH. In LTE, there may be four or more different PDCCH formats defined with different numbers of CCEs (e.g., aggregation levels, L=1, 2, 4, or 8).

[0043] Some implementations may use the concept of resource allocation for control channel information, which is an extension of the above concept. For example, some implementations may utilize an enhanced PDCCH (EPDCCH) that uses PDSCH resources for control information transmission. One or more enhanced CCEs (ECCEs) may be used to transmit EPDCCH. Similar to the above, each ECCE may correspond to nine sets of four physical resource elements, collectively referred to as enhanced REGs (EREGs). ECCEs may have other numbers of EREGs.

[0044] The RAN nodes 111 are configured to communicate with each other using the interface 112. In an example, such as if the system 100 is an LTE system (eg, when the core network 120 is Figure 2101 ), the interface 112 may be an X2 interface 112. The X2 interface may be defined between two or more RAN nodes 111 (e.g., two or more eNBs, etc.) connected to the EPC 120, or between two eNBs connected to the EPC 120, or both. In some implementations, the X2 interface may include an X2 user plane interface (X2-U) and an X2 control plane interface (X2-C). The X2-U may provide a flow control mechanism for user packets transmitted over the X2 interface, and may be used to transmit information about the delivery of user data between eNBs. For example, the X2-U may provide specific sequence number information about user data transmitted from the primary eNB to the secondary eNB; information about successful in-sequence delivery of PDCP protocol data units (PDUs) from the secondary eNB to the UE 101 for user data; information about PDCP PDUs that were not delivered to the UE 101; information about the current minimum expected buffer size at the secondary eNB for transmitting user data to the UE; and the like. X2-C can provide intra-LTE access mobility functions, including context transfer from the source eNB to the target eNB, or user plane transmission control; load management function; inter-cell interference coordination function; and so on.

[0045] In some implementations, such as if system 100 is a 5G NR system (e.g., when core network 120 is Figure 3), the interface 112 may be an Xn interface 112. The Xn interface may be defined between two or more RAN nodes 111 (e.g., two or more gNBs, etc.) connected to the 5G core network 120, between a RAN node 111 (e.g., a gNB) and an eNB connected to the 5G core network 120, or between two eNBs connected to the 5G core network 120, or a combination of the above. In some specific implementations, the Xn interface may include an Xn user plane (Xn-U) interface and an Xn control plane (Xn-C) interface. The Xn-U may provide non-guaranteed delivery of user plane PDUs and support / provide data forwarding and flow control functions. The Xn-C may provide management and error handling functions for managing the functions of the Xn-C interface; mobility support for UE 101 in a connected mode (e.g., CM-CONNECTED), including functions for managing UE mobility in a connected mode between one or more RAN nodes 111; and the like. Mobility support may include context transfer from the old (source) serving RAN node 111 to the new (target) serving RAN node 111, and control of the user plane tunnel between the old (source) serving RAN node 111 and the new (target) serving RAN node 111. The protocol stack of Xn-U may include a transport network layer built on an Internet Protocol (IP) transport layer, and a GPRS Tunneling Protocol (GTP-U) layer of the user plane on top of a User Datagram Protocol (UDP) or IP layer, or both, to carry user plane PDUs. The Xn-C protocol stack may include an application layer signaling protocol (referred to as the Xn Application Protocol (Xn-AP or XnAP)) and a transport network layer (TNL) built on a stream control transmission protocol (SCTP). SCTP may be on top of the IP layer and may provide guaranteed delivery of application layer messages. In the transport IP layer, point-to-point transport is used to deliver signaling PDUs. In other specific implementations, the Xn-U protocol stack or the Xn-C protocol stack or both may be the same as or similar to the user plane and / or control plane protocol stacks shown and described herein.

[0046] RAN 110 is shown as being communicatively coupled to a core network 120 (referred to as "CN 120"). CN 120 includes one or more network elements 122 configured to provide various data and telecommunication services to customers / subscribers (e.g., users of UE 101) connected to CN 120 using RAN 110. Components of CN 120 may be implemented in one physical node or separate physical nodes, and may include components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). In some specific implementations, network function virtualization (NFV) may be used to virtualize some or all of the network node functions described herein using executable instructions stored in one or more computer-readable storage media, as will be described in further detail below. A logical instance of CN 120 may be referred to as a network slice, and a logical instance of a portion of CN 120 may be referred to as a network sub-slice. NFV architecture and infrastructure may be used to virtualize one or more network functions onto physical resources comprising a combination of industry-standard server hardware, storage hardware, or switches (alternatively performed by proprietary hardware). In other words, a NFV system may be used to perform virtual or reconfigurable implementations, or both, of one or more network components or functions.

[0047] The application server 130 may be an element that provides applications that use IP bearer resources with the core network (e.g., UMTS packet service (PS) domain, LTE PS data services, etc.). The application server 130 may also be configured to support one or more communication services for the UE 101 (e.g., VoIP sessions, PTT sessions, group communication sessions, social network services, etc.) using the CN 120. The application server 130 may communicate with one or more network elements 112 using the IP communication interface 125.

[0048] In some implementations, CN 120 may be a 5G core network (referred to as "5GC 120" or "5G core network 120"), and RAN 110 may be connected to CN 120 using a next generation interface 113. In some implementations, the next generation interface 113 may be divided into two parts: a next generation user plane interface 114, which carries traffic data between the RAN node 111 and the UPF (user plane function); and an S1 control plane interface 115, which is a signaling interface between the RAN node 111 and the access and mobility management function (AMF). Reference Figure 3 Discussing in more detail, CN 120 is an example of a 5G core network.

[0049] In some implementations, the CN 120 may be an EPC (referred to as “EPC 120” or the like), and the RAN 110 may be connected to the CN 120 using an S1 interface 113. In some implementations, the S1 interface 113 may be divided into two parts: an S1 user plane (S1-U) interface 114, which carries traffic data between the RAN node 111 and a serving gateway (S-GW); and an S1-MME interface 115, which is a signaling interface between the RAN node 111 and a mobility management entity (MME).

[0050] Figure 2 An exemplary architecture of a system 200 including a first CN 220 is shown. In this example, the system 200 may implement the LTE standard such that the CN 220 is a Figure 1 In addition, UE 201 may communicate with EPC 220 of CN 120. Figure 1 The UE 101 is the same as or similar to the UE 101, and the E-UTRAN 210 may be Figure 1 The CN 220 may be a RAN that is the same as or similar to the RAN 110 of the present invention and may include the RAN node 111 discussed previously. The CN 220 may include an MEE 221, an S-GW 222, a PDN Gateway (P-GW) 223, a High Speed ​​Packet Access (HSS) function 224, and a Serving GPRS Support Node (GENEVA) 225.

[0051] The MME 221 may be similar in function to the control plane of a traditional SGSN, and may implement mobility management (MM) functions to keep track of the current location of the UE 201. The MME 221 may perform various mobility management processes to manage mobility aspects of the access, such as gateway selection and tracking area list management. Mobility management (also referred to as "EPSMM" or "EMM" in the E-UTRAN system) may refer to all applicable procedures, methods, data stores, etc. for maintaining knowledge of the current location of the UE 201, providing user identity confidentiality to users / subscribers, or performing other similar services, or a combination thereof, etc. Each UE 201 and the MME 221 may include an EMM sublayer, and when the attachment process is successfully completed, a mobility management context may be established in the UE 201 and the MME 221. The mobility management context may be a data structure or database object that stores mobility management related information of the UE 201. MME 221 may be coupled to HSS 224 using an S6a reference point, to SGSN 225 using an S3 reference point, and to S-GW 222 using an S11 reference point.

[0052] SGSN 225 may be a node that serves UE 201 by tracking the location of individual UE 201 and performing security functions. In addition, SGSN 225 may perform inter-EPC node signaling for mobility between 2G / 3G and E-UTRAN 3GPP access networks; PDN and S-GW selection as specified by MME 221; handling of UE 201 time zone functions, as specified by MME 221; and MME selection for handover to E-UTRAN 3GPP access network, etc. The S3 reference point between MME 221 and SGSN 225 may enable user and bearer information exchange for inter-3GPP access network mobility in an idle state or an active state or both.

[0053] The HSS 224 may include a database for network users that includes subscription-related information for supporting network entities in handling communication sessions. Among other features, the EPC 220 may include one or more HSSs 224, depending on the number of mobile subscribers, the capacity of the equipment, the organization of the network, or a combination thereof. For example, the HSS 224 may provide support for routing, roaming, authentication, authorization, naming / addressing resolution, location dependency, etc. The S6a reference point between the HSS 224 and the MEE 221 may enable the transmission of subscription and authentication data between the HSS 224 and the MEE 221 for authenticating or authorizing user access to the EPC 220.

[0054] The S-GW 222 may terminate the S1 interface 113 toward the RAN 210 ( Figure 2 The S-GW 222 may be a local mobility anchor for inter-RAN node handovers and may also provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful interception, charging, and enforcement of certain policies. The S11 reference point between the S-GW 222 and the MME 221 may provide a control plane between the MME 221 and the S-GW 222. The S-GW 222 may be coupled to the P-GW 223 using the S5 reference point.

[0055] The P-GW 223 may terminate the SGi interface toward the PDN 230. The P-GW 223 may utilize the IP communication interface 125 (see, e.g., Figure 1 ) routes data packets between EPC 220 and external networks such as a network including application server 130 (sometimes referred to as "AF"). In some implementations, P-GW 223 can be communicatively coupled to an application server (e.g., AF) using IP communication interface 125 (see, e.g., FIG. 1 ). Figure 1 Application server 130 or Figure 2The S5 reference point between the P-GW 223 and the S-GW 222 may provide user plane tunneling and tunnel management between the P-GW 223 and the S-GW 222. The S5 reference point may also be used for S-GW 222 relocation due to the mobility of the UE 201 and whether the S-GW 222 needs to be connected to a non-colocated P-GW 223 for the required PDN connectivity. The P-GW 223 may also include nodes for policy enforcement and charging data collection, such as a PCEF (not shown). In addition, the SGi reference point between the P-GW 223 and the packet data network (PDN) 230 may be an operator-external public, private PDN, or an internal operator packet data network, such as for providing IMS services. The P-GW 223 may be coupled to a policy control and charging rules function (PCRF) 226 using the Gx reference point.

[0056] PCRF 226 is a policy and charging control element of EPC 220. In a non-roaming scenario, there may be a single PCRF 226 in a domestic public land mobile network (HPLMN) associated with an Internet Protocol Connectivity Access Network (IP-CAN) session of UE 201. In a roaming scenario with local traffic breakout, there may be two PCRFs associated with the IP-CAN session of UE 201: a domestic PCRF (H-PCRF) in the HPLMN and a visited PCRF (V-PCRF) in a visited public land mobile network (VPLMN). PCRF 226 may be communicatively coupled to application server 230 using P-GW 223. Application server 230 may signal PCRF 226 to indicate a new service flow and select appropriate quality of service (QoS) and charging parameters. PCRF 226 may configure the rule to a PCEF (not shown) with an appropriate traffic flow template (TFT) and QoS class identifier (QCI), which initiates QoS and charging specified by application server 230. The Gx reference point between PCRF 226 and P-GW 223 may allow for the transfer of QoS policies and charging rules from PCRF 226 to PCEF in P-GW 223. The Rx reference point may reside between PDN 230 (or "AF 230") and PCRF 226.

[0057] Figure 3The architecture of the system 300 including the second CN 320 is shown. The system 300 is shown to include a UE 301, which may be the same or similar to the previously discussed UE 101 and UE 201; a RAN 310, which may be the same or similar to the previously discussed RAN 110 and RAN 210, and which may include the previously discussed RAN node 111; and a data network (DN) 303, which may be, for example, an operator service, Internet access, or a 3rd party service; and a 5GC 320. The RAN 310 may be referred to as a 5G access network (5G-AN) or a 5G-RAN. 5GC 320 may include an authentication server function (AUSF) 322; an access and mobility management function (AMF) 321; a session management function (SMF) 324; a network exposure function (NEF) 323; a policy control function (PCF) 326; a network repository function (NRF) 325; a unified data management (UDM) function 327; an application function (AF) 328; a user plane function (UPF) 302; and a network slice selection function (NSSF) 329.

[0058] UPF 302 may act as an anchor point for intra-RAT and inter-RAT mobility, an external PDU session point interconnected with DN 303, and a branch point to support multi-homed PDU sessions. UPF 302 may also perform packet routing and forwarding, perform packet inspection, perform the user plane portion of policy rules, lawful interception of packets (UP collection), perform traffic usage reporting, perform QoS processing (e.g., packet filtering, gating, UL / DL rate enforcement) on the user plane, perform uplink traffic verification (e.g., SDF to QoS flow mapping), transport level packet marking in uplink and downlink, and perform downlink packet buffering and downlink data notification triggering. UPF 302 may include an uplink classifier for supporting routing of traffic flows to data networks. DN 303 may represent various network operator services, Internet access, or third-party services. DN 303 may include or be similar to the application server 130 discussed previously. UPF 302 may interact with SMF 324 using the N4 reference point between SMF 324 and UPF 302.

[0059] AUSF 322 stores data for authentication of UE 301 and handles authentication-related functions. AUSF 322 may facilitate a common authentication framework for various access types. AUSF 322 may communicate with AMF 321 using the N12 reference point between AMF 321 and AUSF 322, and may communicate with UDM 327 using the N13 reference point between UDM 327 and AUSF 322. In addition, AUSF 322 may present an interface based on Nausf services.

[0060] AMF 321 is responsible for registration management (e.g., responsible for registering UE 301, etc.), connection management, reachability management, mobility management, and lawful interception of AMF-related events, as well as access authentication and authorization. AMF 321 can be the termination point of the N11 reference point between AMF 321 and SMF 324. AMF 321 can provide transmission of SM messages between UE 301 and SMF 324, and act as a transparent agent for routing SM messages. AMF 321 can also provide UE 301 and SMSF ( Figure 3 301). The AMF 321 may act as a security anchor function (SEAF), which may include interaction with the AUSF 322 and the UE 301 to, for example, receive intermediate keys established as a result of the UE 301 authentication process. In the case of using universal user identity module (UMTS)-based authentication, the AMF 321 may retrieve security materials from the AUSF 322. The AMF 321 may also include a security context management (SCM) function that receives keys from the SEAF to derive access network specific keys. In addition, the AMF 321 may be a termination point for the RAN control plane interface, which may include or be the N2 reference point between the RAN 310 and the AMF 321. In some specific implementations, the AMF 321 may be a termination point for NAS (N1) signaling and perform NAS encryption and integrity protection.

[0061] The AMF 321 may also support NAS signaling with the UE 301 over an N3 interworking function (IWF) interface (referred to as "N3IWF"). The N3IWF may be used to provide access to untrusted entities. The N3IWF may be the termination point for the N2 interface between the RAN 310 and the AMF 321 for the control plane, and may be the termination point for the N3 reference point between the RAN 310 and the UPF 302 for the user plane. Thus, the AMF 321 may process N2 signaling for PDU sessions and QoS from the SMF 324 and the AMF 321, encapsulate / decapsulate packets for IPSec and N3 tunnels, mark N3 user plane packets in the uplink, and perform QoS corresponding to N3 packet markings, taking into account QoS requirements associated with such markings received over N2. The N3IWF may also relay uplink and downlink control plane NAS signaling between the UE 301 and the AMF 321 using the N1 reference point between the UE 301 and the AMF 321, and relay uplink and downlink user plane packets between the UE 301 and the UPF 302. The N3IWF also provides a mechanism for establishing an IPsec tunnel with the UE 301. The AMF 321 may present an interface based on the Namf service, and may be an N14 reference point between the two AMFs 321 and an N14 reference point between the AMF 321 and the 5G Equipment Identity Register (EIR) ( Figure 3 The termination point of the N17 reference point between the two (not shown).

[0062] UE 301 may register with AMF 321 in order to receive network services. Registration Management (RM) is used to register UE 301 with the network (e.g., AMF 321) or deregister UE 301, and to establish a UE context in the network (e.g., AMF 321). UE 301 may operate in an RM-REGISTERED state or an RM-DEREGISTERED state. In the RM DEREGISTERED state, UE 301 is not registered with the network, and the UE context in AMF 321 does not maintain valid location or routing information of UE 301, so AMF 321 cannot reach UE 301. In the RM-REGISTERED state, UE 301 is registered with the network, and the UE context in AMF 321 may maintain valid location or routing information of UE 301, so AMF 321 may reach UE 301. In the RM-REGISTERED state, UE 301 may perform a mobility registration update procedure, perform a periodic registration update procedure triggered by expiration of a periodic update timer (e.g., to notify the network that UE 301 is still active), and perform a registration update procedure to update UE capability information or renegotiate protocol parameters with the network, etc.

[0063] AMF 321 may store one or more RM contexts for UE 301, each RM context being associated with a specific access to the network. The RM context may be, for example, a data structure or a database object, etc., which indicates or stores the registration status and periodic update timer for each access type. AMF 321 may also store a 5GC mobility management (MM) context that may be the same or similar to the (E)MM context discussed previously. In some specific implementations, AMF 321 may store coverage enhancement mode B restriction parameters for UE 301 in an associated MM context or RM context. AMF 321 may also derive values ​​from the UE's usage setting parameters already stored in the UE context (and / or MM / RM context) when necessary.

[0064] Connection Management (CM) may be used to establish and release a signaling connection between the UE 301 and the AMF 321 over the N1 interface. The signaling connection is used to enable NAS signaling exchange between the UE 301 and the CN 320, and includes a signaling connection between the UE and the RAN (e.g., an RRC connection or a UE-N3IWF connection for non-3GPP access) and an N2 connection of the UE 301 between the AN (e.g., RAN 310) and the AMF 321. In some implementations, the UE 301 may operate in one of two CM modes (CM-IDLE mode or CM-CONNECTED mode). When the UE 301 operates in the CM-IDLE mode, the UE 301 may not have a NAS signaling connection established with the AMF 321 over the N1 interface, and there may be a RAN 310 signaling connection for the UE 301 (e.g., an N2 or N3 connection or both). When UE 301 operates in CM-CONNECTED mode, UE 301 may have a NAS signaling connection established with AMF 321 through an N1 interface, and there may be a RAN 310 signaling connection (e.g., N2 and / or N3 connection) for UE 301. Establishing an N2 connection between RAN 310 and AMF 321 may cause UE 301 to transition from CM-IDLE mode to CM-CONNECTED mode, and when the N2 signaling between RAN 310 and AMF 321 is released, UE 301 may transition from CM-CONNECTED mode to CM-IDLE mode.

[0065] When UE 301 is in CM-CONNECTED state and RRC_NOVATION state, UE 301 may resume RRC connection (e.g., using the connection resumption procedures discussed herein) due to various events such as uplink data pending; mobile initiated NAS signaling procedures; as a response to RAN 310 paging; notifying the network that it has left the RAN notification area; and when the periodic RAN notification area update timer expires. If UE 301 resumes connection in a different NG-RAN node within the same PLMN or equivalent PLMN, the UE AS context is retrieved from the old NG-RAN node and a procedure is triggered towards the CN (see, e.g., 3GPP TS 23.502, clause 4.8.2).

[0066] AMF 321 may include mechanisms for avoiding and handling overload situations, including N2 overload control and NAS congestion control, where N2 overload control may result in RRC rejection, RRC connection release, and unified access restriction.

[0067] In unusual cases, if the AMF 321 has reached an overload condition, the AMF 321 activates NAS level congestion control as specified in clause 5.19.7 of 3GPP TS23.501, and if the 5G-AN is configured to support overload control, the AMF 321 limits the load being generated by the 5G-AN nodes. N2 overload control may be achieved by the AMF 321 invoking the N2 overload procedure (see, e.g., 3GPP TS 38.300 and 3GPP TS38.413) for all or part of the 5G-AN nodes that have N2 connections with the AMF 321. The AMF 321 may include Network Slice Selection Assistance Information (NSSAI), such as a single NNSAI (S-NSSAI) in the NGAP OVERLOAD START message sent to the 5G-AN node to indicate the network slices for which NAS signaling is to be restricted. To reflect the amount of load that AMF 321 wishes to reduce, AMF 321 may adjust the proportion of 5G-AN nodes to which the NGAP OVERLOAD START message is sent and the content of the overload start procedure.

[0068] When NGAP OVERLOAD START is sent by multiple AMF 321s or from the same AMF 321 set in the same PLMN towards the 5G-AN, it should be ensured that the signaling load is evenly distributed within the PLMN and within each AMF set.

[0069] 5G-AN nodes, such as one or more nodes in RAN 310, may support limiting 5G-AN signaling connections when certain UEs 301 (which register or attempt to register with 5GC) attempt signaling connection establishment, as specified in 3GPP TS 38.331 and 3GPP TS36.331. In addition, 5G-AN nodes provide support for blocking of UEs, as described in 3GPP TS 22.261. These mechanisms are further specified in 3GPP TS 38.331 and 3GPP TS 36.331. In terms of 3GPP access types, the signaling connection establishment attempt includes an RRC connection recovery procedure from RRC-Inactive.

[0070] By sending the NGAP OVERLOAD START message, the AMF 321 may request the node of the RAN 310 to impose the following behaviors for the UE 301 being served by the AMF 321: restricting 5G-AN signaling connection requests that are not for emergency situations, not for exception reports, and not for high-priority mobile originated services; or restricting 5G-AN signaling connection requests for uplink NAS signaling transmission to the AMF 321; allowing only 5G-AN signaling connection requests for emergency sessions and mobile terminated services for the AMF 321; or allowing only 5G-AN signaling connection requests for high-priority sessions, exception reports, and mobile terminated services for the AMF 321. Another behavior includes restricting 5G-AN signaling connection requests, where the requested NSSAI at the AS layer includes only the indicated S-NSSAI in the NGAP OVERLOAD START message. This may be applicable to the RRC_INACTIVE connection recovery procedure, where the allowed NSSAI in the stored UE context in the RAN includes only the S-NSSAI included in the NGAP OVERLOAD START. The above can be applied to the RRC connection establishment and RRC connection recovery procedures via 3GPP access and the UE-N3IWF connection establishment via N3GPP access.

[0071] AMF 321 may provide a value indicating the percentage of connection requests to be restricted in NGAP OVERLOAD START, and the 5G-AN node may consider this value for congestion control. When limiting the 5G-AN signaling connection, the 5G-AN indicates an appropriate waiting timer to the UE, which limits further 5G-AN signaling connection requests until the waiting timer expires. During the overload situation, AMF 321 attempts to maintain support for emergency services and for MPS. When AMF 321 is recovering, AMF 321 may send an NGAP OVERLOAD START message with a new percentage value that allows more connection requests to succeed, or send an NGAP OVERLOAD STOP message to the same 5G-AN node that previously sent the NGAP OVERLOAD START message.

[0072] SMF 324 may be responsible for session management (SM), such as session establishment, modification, and release, including tunnel maintenance between UPF and AN nodes; UE IP address allocation and management (including optional authorization); selection and control of UP functions; configuring traffic steering at UPF to route traffic to the correct destination; terminating the interface toward the policy control function; control portion of policy enforcement and QoS; lawful interception (for SM events and interface with LI system); terminating the SM portion of NAS messages; downlink data notification; initiating AN-specific SM information sent to AN via N2 using AMF; and determining the SSC mode of the session. SM may refer to the management of a PDU session, and a PDU session (or "session") may refer to a PDU connectivity service that provides or enables the exchange of PDUs between a UE 301 and a data network (DN) 303 identified by a data network name (DNN). The PDU session may be established upon request by UE 301, modified upon request by UE 301 and 5GC 320, and released upon request by UE 301 and 5GC 320 using NAS SM signaling exchanged between UE 301 and SMF 324 over the N1 reference point. Upon request from an application server, 5GC 320 may trigger a specific application in UE 301. In response to receiving a trigger message, UE 301 may deliver the trigger message (or relevant parts / information of the trigger message) to one or more identified applications in UE 301. The identified applications in UE 301 may establish a PDU session to a specific DNN. SMF 324 may check whether the UE 301 request complies with user subscription information associated with UE 301. In this regard, SMF 324 may retrieve and / or request to receive update notifications about SMF 324 level subscription data from UDM 327.

[0073] The SMF 324 may include some or all of the following roaming functions: handling local execution to apply QoS service level agreements (SLAs) (e.g., in a VPLMN); charging data collection and charging interfaces (e.g., in a VPLMN); lawful interception (e.g., SM events and interfaces with LI systems in a VPLMN); and supporting interaction with external DNs to transport signaling for PDU session authorization / authentication through external DNs. An N16 reference point between two SMFs 324 may be included in the system 300, which in a roaming scenario may be between another SMF 324 in a visited network and an SMF 324 in a home network. In addition, the SMF 324 may present an interface based on Nsmf services.

[0074] NEF 323 may provide components for securely exposing services and capabilities provided by 3GPP network functions for third parties, internal exposure / re-exposure, application functions (e.g., AF 328), edge computing or fog computing systems, etc. In some specific implementations, NEF 323 may authenticate, authorize and / or throttle AF. NEF 323 may also convert information exchanged with AF 328 and information exchanged with internal network functions. For example, NEF 323 may convert between AF service identifiers and internal 5GC information. NEF 323 may also receive information from other network functions (NFs) based on their exposure capabilities. The information may be stored at NEF 323 as structured data or at a data storage NF using a standardized interface. The stored information may then be re-exposed to other NFs and AFs by NEF 323, or used for other purposes such as analysis, or both. In addition, NEF 323 may present an interface based on Nnef services.

[0075] NRF 325 may support service discovery functionality, receive NF discovery requests from NF instances, and provide information about discovered NF instances to NF instances. NRF 325 also maintains information about available NF instances and services supported by these instances. As used herein, the term "instantiation" and the like may refer to the creation of an instance, and "instance" may refer to the specific occurrence of an object, which may occur, for example, during the execution of a program code. In addition, NRF 325 may present an interface based on Nnrf services.

[0076] The PCF 326 may provide for control plane functions to enforce their policy rules, and may also support a unified policy framework for managing network behavior. The PCF 326 may also implement a front end to access subscription information related to policy decisions in the unified data repository (UDR) of the UDM 327. The PCF 326 may communicate with the AMF 321 using the N15 reference point between the PCF 326 and the AMF 321, which may include the PCF 326 and the AMF 321 in the visited network in the case of a roaming scenario. The PCF 326 may communicate with the AF 328 using the N5 reference point between the PCF 326 and the AF 328; and communicate with the SMF 324 using the N7 reference point between the PCF 326 and the SMF 324. The system 300 or the CN 320 or both may also include an N24 reference point between the PCF 326 (in the home network) and the PCF 326 in the visited network. Additionally, PCF 326 may present an interface based on Npcf services.

[0077] UDM 327 may process subscription-related information to support network entities in handling communication sessions, and may store subscription data for UE 301. For example, subscription data may be transferred between UDM 327 and AMF 321 using the N8 reference point between UDM 327 and AMF. UDM 327 may include two parts: an application front end and a UDR ( Figure 3 The front end and UDR are not shown). The UDR may store subscription data and policy data of the UDM 327 and PCF 326, or structured data for exposure and application data (including PFD for application detection, application request information of multiple UEs 301) of the NEF 323, or both. The Nudr service-based interface may be presented by the UDR 221 to allow the UDM 327, PCF 326, and NEF 323 to access a specific set of stored data, as well as read, update (e.g., add, modify), delete, and subscribe to notifications of related data changes in the UDR. The UDM may include a UDM front end, which is responsible for handling credentials, location management, subscription management, etc. In different transactions, several different front ends may serve the same user. The UDM front end accesses the subscription information stored in the UDR, and performs authentication credential processing, user identification processing, access authorization, registration / mobility management, and subscription management. The UDR may interact with the SMF 324 using the N10 reference point between the UDM 327 and the SMF 324. UDM 327 may also support SMS management, where the SMS front end implements application logic similar to that discussed previously. Additionally, UDM 327 may present an interface based on Nudm services.

[0078] AF 328 can provide the influence of applications on traffic routing, provide access to network capability exposure (NCE), and interact with the policy framework for policy control. NCE can be a mechanism that allows 5GC 320 and AF 328 to provide information to each other using NEF 323, which can be used for edge computing implementation. In such implementations, network operators and third-party services can be hosted near the UE 301 access point of the attachment to achieve effective service delivery through reduced end-to-end delay and load on the transmission network. For edge computing implementation, 5GC can select UPF 302 near UE 301 and perform traffic steering from UPF 302 to DN 303 using the N6 interface. This can be based on UE subscription data, UE location and information provided by AF 328. In this way, AF 328 can affect UPF (re) selection and traffic routing. Based on operator deployment, when AF 328 is considered a trusted entity, the network operator can allow AF 328 to interact directly with the relevant NF. In addition, AF 328 can present an interface based on Naf services.

[0079] NSSF 329 may select a set of network slice instances to serve UE 301. If necessary, NSSF 329 may also determine the allowed NSSAI and the mapping to the subscribed S-NSSAI. NSSF 329 may also determine a set of AMFs to serve UE 301, or a list of candidate AMFs 321, based on appropriate configuration and possibly by querying NRF 325. The selection of a set of network slice instances for UE 301 may be triggered by AMF 321, where UE 301 registers by interacting with NSSF 329, which may result in changes to AMF 321. NSSF 329 may interact with AMF 321 using the N22 reference point between AMF 321 and NSSF 329; and may utilize the N31 reference point ( Figure 3 The NSSF 329 may communicate with another NSSF 329 in the visited network (not shown). In addition, the NSSF 329 may present an interface based on the Nnssf service.

[0080] As previously discussed, CN 320 may include SMSF, which may be responsible for SMS subscription checking and verification, and relaying SM messages to or from UE 301 to or from other entities, such as SMS-GMSC / IWMSC / SMS routers. SMS may also interact with AMF 321 and UDM 327 for notification procedures that UE 301 is available for SMS transmission (e.g., setting a UE unreachable flag and notifying UDM 327 when UE 301 is available for SMS).

[0081] CN 320 may also include Figure 3Other elements not shown, such as a data storage system, 5G-EIR, a security edge protection proxy (SEPP), etc. The data storage system may include a structured data storage function (SDSF), an unstructured data storage function (UDSF), or both, etc. Any network function may utilize any NF and UDSF ( Figure 3 The N18 reference point between the UDSF (not shown) stores or retrieves unstructured data to or from the UDSF (e.g., UE context). Each network function may share the UDSF for storing its corresponding unstructured data, or each network function may each have its own UDSF located at or near each network function. In addition, the UDSF may present an interface based on the Nudsf service ( Figure 3 (not shown). 5G-EIR may be a network function that checks the status of a Permanent Equipment Identifier (PEI) to determine whether to blacklist a particular equipment or entity from the network; and SEPP may be a non-transparent proxy that performs topology hiding, message filtering, and policing on the inter-PLMN control plane interface.

[0082] In some implementations, there may be additional or alternative reference points or service-based interfaces, or both, between network function services in a network function. However, for clarity, Figure 3 These interfaces and reference points are omitted. In one embodiment, CN 320 may include an Nx interface, which is an inter-CN interface between an MME (e.g., MME 221) and an AMF 321, so as to achieve intercommunication between CN 320 and CN 220. Other exemplary interfaces or reference points may include an interface based on N5g-EIR services presented by 5G-EIR, an N27 reference point between an NRF in a visited network and an NRF in a home network, or an N31 reference point between an NSSF in a visited network and an NSSF in a home network, and the like.

[0083] In some implementations, the components of CN 220 may be implemented in one physical node or separate physical nodes, and may include components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium). In some implementations, the components of CN 320 may be implemented in the same or similar manner as discussed herein with respect to the components of CN 220. In some implementations, NFV is used to virtualize any or all of the above-mentioned network node functions using executable instructions stored in one or more computer-readable storage media, as described in further detail below. The logical instantiation of CN 220 may be referred to as a network slice, and each logical instantiation of CN 220 may provide specific network capabilities and network characteristics. The logical instantiation of a portion of CN 220 may be referred to as a network sub-slice, which may include P-GW 223 and PCRF 226.

[0084] As used herein, the terms "instantiation" and the like may refer to the creation of an instance, and "instance" may refer to the concrete occurrence of an object, which may occur, for example, during the execution of program code. A network instance may refer to information identifying a domain, which may be used for traffic detection and routing in different IP domains or in the case of overlapping IP addresses. A network slice instance may refer to a set of network function (NF) instances and the resources (e.g., computing, storage, and network resources) required to deploy a network slice.

[0085] Regarding 5G systems (see e.g. Figure 3 ), a network slice may include a RAN part and a CN part. Support for network slicing relies on the principle that traffic for different slices is handled by different PDU sessions. The network can implement different network slices by scheduling or by providing different L1 / L2 configurations or both. If provided by NAS, the UE 301 provides auxiliary information for network slice selection in an appropriate RRC message. In some specific implementations, although the network can support a large number of slices, the UE does not need to support more than 8 slices at the same time.

[0086] The network slice may include the CN 320 control plane and user plane NF, the NG-RAN 310 in the serving PLMN, and the N3IWF function in the serving PLMN. Each network slice may have a different S-NSSAI or a different SST, or both. The NSSAI includes one or more S-NSSAIs, and each network slice is uniquely identified by the S-NSSAI. The network slices may be different for supported features and network function optimizations. In some specific implementations, multiple network slice instances may deliver the same service or feature, but for different groups of UEs 301 (e.g., enterprise users). For example, each network slice may deliver different committed services or may be dedicated to a specific customer or enterprise, or both. In this example, each network slice may have a different S-NSSAI with the same SST but with a different slice differentiator. In addition, a single UE may be served simultaneously by one or more network slice instances using a 5G AN, and the UE may be associated with eight different S-NSSAIs. In addition, an AMF 321 instance serving a single UE 301 may belong to each network slice instance serving the UE.

[0087] Network slicing in the RAN 310 involves RAN slice awareness. RAN slice awareness includes differentiated handling of traffic for different network slices that have been pre-configured. Slice awareness in the RAN 310 is introduced at the PDU session level by indicating the S-NSSAI corresponding to the PDU session in all signaling including PDU session resource information. How the RAN 310 supports enabling slicing in terms of NG-RAN functions (e.g., a set of network functions including each slice) depends on the specific implementation. The RAN 310 selects the RAN portion of the network slice using auxiliary information provided by the UE 301 or 5GC 320, which explicitly identifies one or more network slices in the pre-configured network slices in the PLMN. The RAN 310 also supports resource management and policy enforcement between slices in accordance with the SLA. A single NG-RAN node can support multiple slices, and the RAN 310 can also apply appropriate RRM policies for the SLA in the appropriate location to each supported slice. The RAN 310 can also support QoS differentiation within a slice.

[0088] The RAN 310 may also use the UE assistance information to select an AMF 321 during the initial attach, if available. The RAN 310 uses the assistance information to route the initial NAS to the AMF 321. If the RAN 310 cannot use the assistance information to select the AMF 321, or the UE 301 does not provide any such information, the RAN 310 sends the NAS signaling to the default AMF 321, which may be in the AMF 321 pool. For subsequent access, the UE 301 provides a temporary ID assigned to the UE 301 by the 5GC 320 to enable the RAN 310 to route the NAS message to the appropriate AMF 321, as long as the temporary ID is valid. The RAN 310 is aware of and can reach the AMF 321 associated with the temporary ID. Otherwise, the method for initial attach is applied.

[0089] The RAN 310 supports resource isolation between slices. RAN 310 resource isolation can be achieved with the help of RRM policies and protection mechanisms, which should avoid the shortage of shared resources in the case where one slice interrupts the service level agreement of another slice. In some specific implementations, RAN 310 resources can be fully assigned to a slice. How the RAN 310 supports resource isolation depends on the specific implementation.

[0090] Some slices may be only partially available in the network. Awareness of the RAN 310 of supported slices in its neighboring cells may be beneficial for inter-frequency mobility in connected mode. Slice availability may not change within the registration area of ​​the UE. The RAN 310 and 5GC 320 are responsible for handling service requests for slices that may or may not be available in a given area. Granting or denying access to a slice may depend on factors such as support for the slice, availability of resources, and support of the requested service by the RAN 310.

[0091] UE 301 may be associated with multiple network slices simultaneously. In the case where UE 301 is associated with multiple slices simultaneously, only one signaling connection is maintained and for intra-frequency cell reselection, UE 301 attempts to camp on the best cell. For inter-frequency cell reselection, dedicated priorities may be used to control the frequency that UE 301 camps on. 5GC 320 will verify that UE 301 has the right to access the network slice. Prior to receiving the Initial Context Setup Request message, RAN 310 may be allowed to apply some temporary or local policies based on the perception of the specific slice that UE 301 is requesting access to. During the Initial Context Setup, RAN 310 is informed of the slice whose resources are being requested.

[0092] Figure 4An example of infrastructure equipment 400 is illustrated. Infrastructure equipment 400 (or "system 400") can be implemented as a base station, a radio head, a RAN node (such as the RAN node 111 or AP 106 shown and described previously), an application server 130, or any other component or device discussed herein. In other examples, system 400 can be implemented in or by a UE.

[0093] System 400 includes: application circuit 405, baseband circuit 410, one or more radio front end modules (RFEM) 415, memory circuit 420, power management integrated circuit (PMIC) 425, power tee circuit 430, network controller circuit 435, network interface connector 440, satellite positioning circuit 445 and user interface circuit 450. In some specific implementations, system 400 may include additional elements, such as, for example, memory, storage, display, camera, one or more sensors, or input / output (I / O) interface, or a combination thereof. In other examples, the components described with reference to system 400 may be included in more than one device. For example, various circuits may be separately included in more than one device for CRAN, vBBU or other specific implementations.

[0094] The application circuit 405 may include circuits such as, but not limited to, one or more processors (or processor cores), cache memory, one or more of the following: a low dropout regulator (LDO), an interrupt controller, a serial interface such as SPI, I2C or a general programmable serial interface module, a real-time clock (RTC), a timer-counter including an interval timer and a watchdog timer, a general input / output (I / O or IO), a memory card controller such as a secure digital (SD) multimedia card (MMC) or similar products, a universal serial bus (USB) interface, a mobile industry processor interface (MIPI) interface, and a joint test access group (JTAG) test access port. The processor (or core) of the application circuit 405 may be coupled to or may include a memory or storage element, and may be configured to execute instructions stored in the memory or storage device to enable various applications or operating systems to run on the system 400. In some implementations, the memory or storage element may include on-chip memory circuitry, which may include any suitable volatile or nonvolatile memory such as DRAM, SRAM, EPROM, EEPROM, flash memory, solid-state memory, or combinations thereof, in addition to other types of memory.

[0095] The processor of the application circuit 405 may include, for example, one or more processor cores (CPUs), one or more application processors, one or more graphics processing units (GPUs), one or more reduced instruction set computing (RISC) processors, one or more Acorn RISC Machine (ARM) processors, one or more complex instruction set computing (CISC) processors, one or more digital signal processors (DSPs), one or more FPGAs, one or more PLDs, one or more ASICs, one or more microprocessors or controllers, or a combination thereof, etc. In some specific implementations, the application circuit 405 may include or may be a dedicated processor or controller configured to perform the various techniques described herein. In some specific implementations, the system 400 may not utilize the application circuit 405, and may instead include a dedicated processor or controller to process, for example, IP data received from the EPC or 5GC.

[0096] In some implementations, the application circuit 405 may include one or more hardware accelerators, which may be microprocessors, programmable processing devices, etc. The one or more hardware accelerators may include, for example, computer vision or deep learning accelerators or both. In some implementations, the programmable processing device may be: one or more field programmable devices (FPDs), such as field programmable gate arrays (FPGAs), etc.; programmable logic devices (PLDs), such as complex PLDs (CPLDs) or high capacity PLDs (HCPLDs); ASICs, such as structured ASICs; programmable SoCs (PSoCs), or combinations thereof, etc. In such implementations, the circuits of the application circuit 405 may include logic blocks or logic architectures, as well as other interconnected resources that can be programmed to perform various functions, such as the processes, methods, functions described herein. In some implementations, the circuitry of application circuit 405 may include a memory unit (e.g., an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, a static memory (e.g., a static random access memory (SRAM) or an antifuse)) for storing logic blocks, logic structures, data, or other data in a lookup table (LUT) or the like.

[0097] Baseband circuit 410 may be implemented, for example, as a solder-in substrate including one or more integrated circuits, a single packaged integrated circuit soldered to a main circuit board, or a multi-chip module containing two or more integrated circuits.

[0098] The user interface circuit 450 may include one or more user interfaces designed to enable a user to interact with the system 400 or a peripheral component interface designed to enable a peripheral component to interact with the system 400. The user interface may include, but is not limited to, one or more physical or virtual buttons (e.g., a reset button), one or more indicators (e.g., light emitting diodes (LEDs)), a physical keyboard or keypad, a mouse, a touch pad, a touch screen, a speaker or other audio transmitting device, a microphone, a printer, a scanner, a headset, a display screen or display device, or a combination thereof, etc. The peripheral component interface may include, but is not limited to, a non-volatile memory port, a universal serial bus (USB) port, an audio jack, a power interface, etc.

[0099] The radio front end module (RFEM) 415 may include a millimeter wave (mmWave) RFEM and one or more sub-millimeter wave radio frequency integrated circuits (RFICs). In some implementations, the one or more sub-millimeter wave RFICs may be physically separated from the mmWave RFEM. The RFIC may include one or more antennas or antenna arrays (see, e.g., Figure 6 The antenna array 611 is connected to the RFEM, and the RFEM can be connected to multiple antennas. In some specific implementations, the radio functions of both millimeter wave and sub-millimeter wave can be implemented in the same physical RFEM 415 that combines both millimeter wave antennas and sub-millimeter waves.

[0100] The memory circuit 420 may include one or more of the following: a volatile memory, such as a dynamic random access memory (DRAM) or a synchronous dynamic random access memory (SDRAM); and a non-volatile memory (NVM), such as a high-speed electrically erasable memory (commonly referred to as flash memory), a phase change random access memory (PRAM), or a magnetoresistive random access memory (MRAM), or a combination thereof, etc. For example, the memory circuit 420 may be implemented as one or more of the following: a solder-in packaged integrated circuit, a socketed memory module, and a plug-in memory card.

[0101] The PMIC 425 may include a voltage regulator, a surge protector, a power alarm detection circuit, and one or more backup power sources, such as a battery or capacitor. The power alarm detection circuit may detect one or more of a brownout (undervoltage) and a surge (overvoltage) condition. The power tee circuit 430 may provide power extracted from the network cable to provide both power and data connections for the infrastructure equipment 400 using a single cable.

[0102] The network controller circuit 435 may provide connectivity to the network using a standard network interface protocol such as Ethernet, Ethernet based on a GRE tunnel, Ethernet based on Multi-Protocol Label Switching (MPLS), or some other suitable protocol. Network connectivity may be provided to and from the infrastructure equipment 400 using a network interface connector 440 using a physical connection, which may be an electrical connection (commonly referred to as a "copper interconnect"), an optical connection, or a wireless connection. The network controller circuit 435 may include one or more dedicated processors or FPGAs, or both, for communicating using one or more of the aforementioned protocols. In some implementations, the network controller circuit 435 may include multiple controllers for providing connectivity to other networks using the same or different protocols.

[0103] The positioning circuit 445 includes circuits for receiving and decoding signals transmitted or broadcast by a positioning network of a global navigation satellite system (GNSS). Examples of GNSS include the United States' Global Positioning System (GPS), Russia's Global Navigation System (GLONASS), the European Union's Galileo system, China's Beidou Navigation Satellite System, regional navigation systems or GNSS augmentation systems (e.g., using the Indian constellation (NAVIC), Japan's Quasi-Zenith Satellite System (QZSS), France's Doppler Orbit Chart and Satellite Integrated Radio Positioning (DORIS) for navigation), etc. The positioning circuit 445 may include various hardware elements (e.g., including hardware devices such as switches, filters, amplifiers, antenna elements, etc. for facilitating OTA communications) to communicate with components of the positioning network such as navigation satellite constellation nodes. In some specific implementations, the positioning circuit 445 may include a micro technology (micro PNT) IC for positioning, navigation, and timing that uses a master timing clock to perform position tracking and estimation without GNSS assistance. The positioning circuit 445 may also be part of or interact with the baseband circuit 410 or the RFEM 415 or both to communicate with nodes and components of the positioning network. The positioning circuit 445 may also provide data (e.g., location data, time data) to the application circuit 405, which may use the data to synchronize operations with various infrastructures (e.g., RAN node 111, etc.).

[0104] Figure 4 The components shown can communicate with each other using interface circuits that can include any number of bus or interconnect (IX) technologies, such as industry standard architecture (ISA), extended ISA (EISA), peripheral component interconnect (PCI), peripheral component interconnect extended (PCIx), PCI express (PCIe), or any number of other technologies. The bus or IX can be a proprietary bus, for example, used in a SoC-based system. Other bus or IX systems can be included, such as an I2C interface, an SPI interface, a point-to-point interface, and a power bus, etc.

[0105] Figure 5 An example of a platform 500 (or "device 500") is illustrated. In some implementations, the computer platform 500 may be suitable for use as a UE 101, 201, 301, an application server 130, or any other component or device discussed herein. The platform 500 may include any combination of components shown in the example. The components (or portions thereof) of the platform 500 may be implemented as an integrated circuit (IC), a discrete electronic device, or other modules, logic, hardware, software, firmware, or a combination thereof adapted in the computer platform 500, or implemented as components otherwise combined within the chassis of a larger system. Figure 5 The block diagram is intended to show a high-level view of the components of platform 500. However, in some implementations, platform 500 may include fewer, additional, or alternative components, or Figure 5 Different arrangements of components shown.

[0106] The application circuit 505 includes circuits such as, but not limited to, one or more processors (or processor cores), cache memory, and one or more LDOs, interrupt controllers, serial interfaces (such as SPI), I2C or general programmable serial interface modules, RTCs, timer-counters (including interval timers and watchdog timers), general I / Os, memory card controllers (such as SD MMC or similar controllers), USB interfaces, MIPI interfaces, and JTAG test access ports. The processor (or core) of the application circuit 505 may be coupled to or may include a memory / storage element and may be configured to execute instructions stored in the memory or storage device to enable various applications or operating systems to run on the platform 500. In some specific implementations, the memory or storage element may include an on-chip memory circuit, which may include any suitable volatile or non-volatile memory, such as DRAM, SRAM, EPROM, EEPROM, flash memory, solid-state memory, or a combination thereof, in addition to other types of memory.

[0107] The processor of the application circuit 505 may include, for example, one or more processor cores, one or more application processors, one or more GPUs, one or more RISC processors, one or more ARM processors, one or more CISC processors, one or more DSPs, one or more FPGAs, one or more PLDs, one or more ASICs, one or more microprocessors or controllers, multi-threaded processors, ultra-low voltage processors, embedded processors, some other known processing elements, or any suitable combination thereof. In some specific implementations, the application circuit 405 may include or may be a dedicated processor / controller for performing the techniques described herein. In some specific implementations, the application circuit 505 may be part of a system on a chip (SoC), in which the application circuit 505 and other components are formed as a single integrated circuit or a single package.

[0108] In addition or alternatively, the application circuit 505 may include circuits such as, but not limited to, one or more field programmable devices (FPDs), such as FPGAs; programmable logic devices (PLDs), such as complex PLDs (CPLDs), high capacity PLDs (HCPLDs); ASICs, such as structured ASICs; programmable SoCs (PSoCs), or combinations thereof, etc. In some implementations, the application circuit 505 may include logic blocks or logic structures, and other interconnected resources that can be programmed to perform various functions, such as the processes, methods, functions described herein. In some implementations, the application circuit 505 may include memory cells (e.g., erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, static memory (e.g., static random access memory (SRAM), or anti-fuse)) for storing logic blocks, logic structures, data, or other data in a lookup table (LUT), etc.

[0109] Baseband circuit 510 may be implemented, for example, as a solder-in substrate including one or more integrated circuits, a single packaged integrated circuit soldered to a main circuit board, or a multi-chip module containing two or more integrated circuits. Figure 6 The various hardware electronic components of baseband circuit 510 are discussed.

[0110] The RFEM 515 may include a millimeter wave (mmWave) RFEM and one or more sub-millimeter wave radio frequency integrated circuits (RFICs). In some implementations, the one or more sub-millimeter wave RFICs may be physically separated from the mmWave RFEM. The RFIC may include one or more antennas or antenna arrays (see, e.g., Figure 6The antenna array 611) is connected to the RFEM, and the RFEM can be connected to multiple antennas. In some specific implementations, the radio functions of both millimeter wave and sub-millimeter wave can be implemented in the same physical RFEM 515 that combines both millimeter wave antennas and sub-millimeter waves.

[0111] The memory circuit 520 may include any number and type of memory devices for providing a fixed amount of system memory. For example, the memory circuit 520 may include one or more of the following: volatile memory, such as random access memory (RAM), dynamic RAM (DRAM) or synchronous dynamic RAM (SDRAM); and non-volatile memory (NVM), such as high-speed electrically erasable memory (commonly referred to as flash memory), phase change random access memory (PRAM), or magnetoresistive random access memory (MRAM), or a combination thereof, etc. The memory circuit 520 may be developed according to the Joint Electron Device Engineering Council (JEDEC) based low power double data rate (LPDDR) design such as LPDDR2, LPDDR3, LPDDR4, etc. The memory circuit 520 may be implemented as one or more of the following: a solder-in package integrated circuit, a single die package (SDP), a dual die package (DDP) or a quad die package (Q17P), a socketed memory module, a dual in-line memory module (DIMM) including a micro DIMM or a mini DIMM, or soldered to a motherboard using a ball grid array (BGA). In a low-power implementation, the memory circuit 520 may be an on-chip memory or register associated with the application circuit 505. To provide persistent storage of information (such as data, applications, operating systems, etc.), the memory circuit 520 may include one or more mass storage devices, which may include, for example, a solid-state disk drive (SSDD), a hard disk drive (HDD), a micro HDD, a resistive change memory, a phase change memory, a holographic memory, or a chemical memory, etc.

[0112] The removable memory circuit 523 may include a device, circuit, housing, casing, port or socket, etc., for coupling a portable data storage device to the platform 500. These portable data storage devices may be used for mass storage and may include, for example, flash memory cards (e.g., secure digital (SD) cards, micro SD cards, xD picture cards, etc.), as well as USB flash drives, optical disks, or external HDDs, or combinations thereof, etc.

[0113] The platform 500 may further include an interface circuit (not shown) for connecting external devices to the platform 500. External devices connected to the platform 500 using the interface circuit include a sensor circuit 521 and an electromechanical component (EMC) 522, and a removable memory device coupled to a removable memory circuit 523.

[0114] Sensor circuit 521 includes a device, module, or subsystem that is intended to detect events or changes in its environment and send information about the detected events (e.g., sensor data) to one or more other devices, modules, or subsystems. Examples of such sensors include: an inertial measurement unit (IMU), such as an accelerometer, gyroscope, or magnetometer; a microelectromechanical system (MEMS) or nanoelectromechanical system (NEMS) including a three-axis accelerometer, a three-axis gyroscope, or a magnetometer; a liquid level sensor; a flow sensor; a temperature sensor (e.g., a thermistor); a pressure sensor; a barometric pressure sensor; a gravity meter; an altimeter; an image capture device (e.g., a camera or a lensless aperture); a light detection and ranging (LiDAR) sensor; a proximity sensor (e.g., an infrared radiation detector, etc.), a depth sensor, an ambient light sensor, an ultrasonic transceiver; a microphone or other audio capture device, or a combination thereof, etc.

[0115] The EMC 522 includes devices, modules or subsystems that are intended to enable the platform 500 to change its state, position, or orientation or to move or control a mechanism, system or subsystem. In addition, the EMC 522 may be configured to generate messages or signaling and send messages or signaling to other components of the platform 500 to indicate the current state of the EMC 522. Examples of EMC 522 include one or more power switches, relays (such as electromechanical relays (EMRs) or solid-state relays (SSRs)), actuators (e.g., valve actuators), audible sound generators, visual warning devices, motors (e.g., DC motors or stepper motors), wheels, thrusters, propellers, claws, clamps, hooks, or combinations thereof, in addition to other electromechanical components. In some specific implementations, the platform 500 is configured to operate one or more EMCs 522 based on one or more capture events, instructions or control signals received from a service provider or a client or both.

[0116] In some specific implementations, the interface circuit may connect the platform 500 to the positioning circuit 545. The positioning circuit 545 includes a circuit for receiving and decoding signals transmitted or broadcast by a positioning network of a GNSS. Examples of GNSS may include the United States' GPS, Russia's GLONASS, the European Union's Galileo system, China's Beidou navigation satellite system, a regional navigation system or a GNSS augmentation system (e.g., NAVIC), Japan's QZSS, France's DORIS, etc. The positioning circuit 545 may include various hardware elements (e.g., including hardware devices such as switches, filters, amplifiers, antenna elements, etc. for facilitating OTA communication) to communicate with components of the positioning network such as navigation satellite constellation nodes. In some specific implementations, the positioning circuit 545 may include a micro PNT IC that uses a master timing clock to perform position tracking or estimation without GNSS assistance. The positioning circuit 545 may also be part of or interact with the baseband circuit 410 or RFEM 515 or both to communicate with nodes and components of the positioning network. Positioning circuitry 545 may also provide data (eg, position data, time data) to application circuitry 505, which may use the data to synchronize operations with various infrastructure (eg, radio base stations), for turn-by-turn navigation applications, and the like.

[0117] In some implementations, the interface circuit may connect the platform 500 with a near field communication (NFC) circuit 540. The NFC circuit 540 is configured to provide contactless short-range communication based on the radio frequency identification (RFID) standard, wherein magnetic field induction is used to enable communication between the NFC circuit 540 and an NFC-enabled device (e.g., an "NFC touch point") external to the platform 500. The NFC circuit 540 includes an NFC controller coupled to an antenna element and a processor coupled to the NFC controller. The NFC controller may be a chip or IC that provides NFC functionality to the NFC circuit 540 by executing an NFC controller firmware and an NFC stack. The NFC stack may be executed by the processor to control the NFC controller, and the NFC controller firmware may be executed by the NFC controller to control the antenna element to transmit a short-range RF signal. The RF signal may power a passive NFC tag (e.g., a microchip embedded in a sticker or wristband) to transfer stored data to the NFC circuit 540, or initiate data transfer between the NFC circuit 540 and another active NFC device (e.g., a smart phone or an NFC-enabled POS terminal) close to the platform 500.

[0118] The driver circuit 546 may include software and hardware elements for controlling specific devices embedded in, attached to, or otherwise communicatively coupled to the platform 500. The driver circuit 546 may include various drivers to allow other components of the platform 500 to interact with or control various input / output (I / O) devices that may be present in or connected to the platform 500. For example, the driver circuit 546 may include: a display driver for controlling and allowing access to a display device, a touch screen driver for controlling and allowing access to a touch screen interface of the platform 500, a sensor driver for obtaining sensor readings of the sensor circuit 521 and controlling and allowing access to the sensor circuit 521, an EMC driver for obtaining actuator positions or controlling and allowing access to the EMC 522, a camera driver for controlling and allowing access to an embedded image capture device, and an audio driver for controlling and allowing access to one or more audio devices.

[0119] A power management integrated circuit (PMIC) 525 (also referred to as “power management circuit 525”) may manage power provided to various components of the platform 500. Specifically, the PMIC 525 may control power selection, voltage scaling, battery charging, or DC-DC conversion with respect to the baseband circuit 510. The PMIC 525 may be included when the platform 500 is capable of being powered by a battery 530, for example, when the device is included in a UE 101, 201, 301.

[0120] In some implementations, the PMIC 525 may control or otherwise be part of various power saving mechanisms of the platform 500. For example, if the platform 500 is in the RRC_CONNECTED state, in which the platform is still connected to the RAN node because it expects to receive traffic soon, then after a period of inactivity, the platform may enter a state associated with DRX or eDRX. During this state, the platform 500 may be powered off for short time intervals, thereby saving power. If there is no data traffic activity for a longer period of time, the platform 500 may transition to the RRC_IDLE state, in which it is disconnected from the network and does not perform operations such as channel quality feedback or handover. This may allow the platform 500 to enter a very low power state in which it periodically wakes up to listen to the network and then powers off again. In some implementations, the platform 500 may not receive data in the RRC_IDLE state, but must transition back to the RRC_CONNECTED state to receive data. Additional power saving modes may prevent the device from using the network for longer than the paging interval (ranging from a few seconds to a few hours). During this time, the device may not be able to connect to the network and may lose power completely. Any data sent during this time may be significantly delayed, and it is assumed that the delay is acceptable.

[0121] The battery 530 can power the platform 500, but in some implementations, the platform 500 can be deployed in a fixed location and can have a power source coupled to a power grid. The battery 530 can be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, or a lithium-air battery, etc. In some implementations, such as in V2X applications, the battery 530 can be a typical lead-acid car battery.

[0122] In some implementations, the battery 530 may be a "smart battery" that includes or is coupled to a battery management system (BMS) or a battery monitoring integrated circuit. The BMS may be included in the platform 500 to track the state of charge (SoCh) of the battery 530. The BMS may be used to monitor other parameters of the battery 530, such as the state of health (SoH) and state of function (SoF) of the battery 530 to provide fault prediction. The BMS may transmit information about the battery 530 to the application circuit 505 or other components of the platform 500. The BMS may also include an analog-to-digital (ADC) converter that allows the application circuit 505 to directly monitor the voltage of the battery 530 or the current from the battery 530. The battery parameters may be used to determine actions that the platform 500 may perform, such as transmission frequency, network operation, sensing frequency, etc.

[0123] The user interface circuit 550 includes various input / output (I / O) devices present in or connected to the platform 500, and includes one or more user interfaces designed to implement user interaction with the platform 500 or peripheral component interfaces designed to implement interaction with peripheral components of the platform 500. The user interface circuit 550 includes input device circuits and output device circuits. The input device circuit includes any physical or virtual means for accepting input, including one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touch screen, a microphone, a scanner, or a headset, or a combination thereof, etc. The output device circuit includes any physical or virtual means for displaying information or otherwise conveying information (such as sensor readings, actuator positions, or other information). The output device circuitry may include any number or combination of audio or visual displays, including one or more simple visual outputs or indicators (e.g., binary state indicators (e.g., light emitting diodes (LEDs)), multi-character visual outputs, or more complex outputs, such as a display device or touch screen (e.g., a liquid crystal display (LCD), an LED display, a quantum dot display, or a projector), where the output of characters, graphics, or multimedia objects is generated or produced by the operation of the platform 500. The output device circuitry may also include a speaker or other audio emitting device, or a printer. In some implementations, the sensor circuitry 521 may be used as an input device circuit (e.g., an image capture device, or a motion capture device) and one or more EMCs may be used as an output device circuit (e.g., an actuator for providing tactile feedback). In another example, an NFC circuit may be included to read an electronic tag or connect to another NFC-enabled device, the NFC circuitry including an NFC controller and a processing device coupled to an antenna element. The peripheral component interface may include, but is not limited to, a non-volatile memory port, a USB port, an audio jack, or a power interface.

[0124] Although not shown, the components of platform 500 can communicate with each other using a suitable bus or interconnect (IX) technology, which can include any number of technologies, including ISA, EISA, PCI, PCIx, PCIe, time-triggered protocol (TTP) systems, FlexRay systems, or any number of other technologies. The bus or IX can be a proprietary bus or IX, for example, used in a SoC-based system. Other bus or IX systems can be included, such as an I2C interface, an SPI interface, a point-to-point interface, and a power bus, etc.

[0125] Figure 6 6 and 615. The baseband circuit 610 may correspond to Figure 4 The baseband circuit 410 and Figure 5The baseband circuit 510 of FIG. RFEM 615 may correspond to Figure 4 RFEM415 and Figure 5 RFEM 515. As shown, RFEM 615 may include radio frequency (RF) circuitry 606, front end module (FEM) circuitry 608, and antenna array 611 coupled together.

[0126] The baseband circuit 610 includes circuits configured to execute various radio or network protocols and control functions that enable communication with one or more radio networks using the RF circuit 606. The radio control functions may include, but are not limited to, signal modulation and demodulation, encoding and decoding, and radio frequency shifting. In some specific implementations, the modulation and demodulation circuits of the baseband circuit 610 may include fast Fourier transform (FFT), precoding, or constellation mapping and demapping functions. In some specific implementations, the encoding and decoding circuits of the baseband circuit 610 may include convolution, tail-biting convolution, turbo, Viterbi, or low-density parity check (LDPC) encoder and decoder functions. The modulation and demodulation and encoder and decoder functions are not limited to these examples and may include other suitable functions in other examples. The baseband circuit 610 is configured to process baseband signals received from the receive signal path of the RF circuit 606 and generate baseband signals for the transmit signal path of the RF circuit 606. The baseband circuit 610 is configured to communicate with application circuits (e.g., Figure 4 and Figure 5 4 and 505) to generate and process baseband signals and control the operation of RF circuitry 606. Baseband circuitry 610 may handle various radio control functions.

[0127] The aforementioned circuits and control logic components of the baseband circuit 610 may include one or more single-core or multi-core processors. For example, the one or more processors may include a 3G baseband processor 604A, a 4G or LTE baseband processor 604B, a 5G or NR baseband processor 604C, or some other baseband processor 604D for other existing generations, generations under development, or generations to be developed in the future (e.g., the sixth generation (6G)). In some specific implementations, some or all of the functions of the baseband processors 604A-D may be included in a module stored in the memory 604G and executed using a processor such as a central processing unit (CPU) 604E. In some specific implementations, some or all of the functions of the baseband processors 604A-D may be provided as a hardware accelerator (e.g., FPGA or ASIC) loaded with appropriate bitstreams or logic blocks stored in corresponding memory units. In some specific implementations, the memory 604G may store program code of a real-time OS (RTOS), which, when executed by the CPU 604E (or other baseband processor), is used to enable the CPU 604E (or other baseband processor) to manage resources, schedule tasks, or perform other operations of the baseband circuit 610. In addition, the baseband circuit 610 includes one or more audio digital signal processors (DSPs) 604F. The audio DSP 604F includes elements for compression and decompression and echo cancellation, and may include other suitable processing elements.

[0128] In some implementations, each of the processors 604A-604E includes a corresponding memory interface to send data to and receive data from the memory 604G. The baseband circuit 610 may also include one or more interfaces for communicatively coupling to other circuits or devices, such as an interface for sending data to and receiving data from a memory external to the baseband circuit 610; an interface for sending data to and receiving data from a memory external to the baseband circuit; Figure 4 and Figure 5 The application circuit interface for sending data to the application circuit 405, 505 and receiving data from the application circuit; Figure 6 RF circuit 606 to send data and receive data from the RF circuit; an RF circuit interface for receiving data from one or more wireless hardware elements (e.g., near field communication (NFC) components, Low power consumption components, components, etc.) to send data and receive data from these wireless hardware elements; and a power management interface for sending power or control signals to the PMIC 525 and receiving power or control signals from the PMIC.

[0129] In some specific implementations (which may be combined with the above examples), the baseband circuit 610 includes one or more digital baseband systems that are coupled to each other and to the CPU subsystem, the audio subsystem, and the interface subsystem using an interconnect subsystem. The digital baseband subsystem may also be coupled to the digital baseband interface and the mixed signal baseband subsystem using another interconnect subsystem. Each of the interconnect subsystems may include a bus system, a point-to-point connector, a network on chip (NOC) structure, or some other suitable bus or interconnect technology, such as those discussed herein. The audio subsystem may include a DSP circuit, a buffer memory, a program memory, a voice processing accelerator circuit, a data converter circuit such as an analog-to-digital converter circuit and a digital-to-analog converter circuit, an analog circuit including one or more of an amplifier and a filter, and the like. In some specific implementations, the baseband circuit 610 may include a protocol processing circuit having one or more control circuit instances (not shown) to provide control functions for a digital baseband circuit or a radio frequency circuit (e.g., a radio front end module 615).

[0130] although Figure 6 Not shown, but in some implementations, the baseband circuit 610 includes various processing devices (e.g., a "multi-protocol baseband processor" or "protocol processing circuit") for operating one or more wireless communication protocols and various processing devices for implementing PHY layer functions. In some implementations, the PHY layer functions include the aforementioned radio control functions. In some implementations, the protocol processing circuit operates or implements various protocol layers or entities of one or more wireless communication protocols. For example, when the baseband circuit 610 or the RF circuit 606 or both are part of a millimeter wave communication circuit or some other suitable cellular communication circuit, the protocol processing circuit may operate an LTE protocol entity or a 5G NR protocol entity or both. In this example, the protocol processing circuit may operate MAC, RLC, PDCP, SDAP, RRC, and NAS functions. In some implementations, when the baseband circuit 610 or the RF circuit 606 or both are part of a Wi-Fi communication system, the protocol processing circuit may operate one or more IEEE-based protocols. In this example, the protocol processing circuit may operate Wi-Fi MAC and logical link control (LLC) functions. The protocol processing circuitry may include one or more memory structures (e.g., 604G) for storing program code and data for operating protocol functions, and one or more processing cores for executing program code and performing various operations using data. The baseband circuitry 610 may also support radio communications for more than one wireless protocol.

[0131] The various hardware elements of the baseband circuit 610 discussed herein may be implemented as, for example, a solder-in substrate including one or more integrated circuits (ICs), a single packaged integrated circuit soldered to a main circuit board, or a multi-chip module containing two or more ICs. In some implementations, the components of the baseband circuit 610 may be appropriately combined in a single chip or a single chipset, or disposed on the same circuit board. In some implementations, some or all of the components of the baseband circuit 610 and the RF circuit 606 may be implemented together, such as, for example, a system on a chip (SoC) or a system-in-package (SiP). In some implementations, some or all of the components of the baseband circuit 610 may be implemented as a separate SoC communicatively coupled to the RF circuit 606 (or multiple instances of the RF circuit 606). In some implementations, some or all of the components of the baseband circuit 610 and the application circuits 405, 505 may be implemented together as a separate SoC mounted to the same circuit board (e.g., a "multi-chip package").

[0132] In some implementations, the baseband circuit 610 may provide communications compatible with one or more radio technologies. For example, the baseband circuit 610 may support communications with an E-UTRAN or other WMAN, WLAN, or WPAN. Examples in which the baseband circuit 610 is configured to support radio communications of more than one wireless protocol may be referred to as a multi-mode baseband circuit.

[0133] The RF circuit 606 can use modulated electromagnetic radiation to achieve communication with a wireless network through a non-solid medium. In some specific implementations, the RF circuit 606 may include switches, filters, or amplifiers, among other components, to facilitate communication with the wireless network. The RF circuit 606 may include a receive signal path, which may include circuits for down-converting RF signals received from the FEM circuit 608 and providing baseband signals to the baseband circuit 610. The RF circuit 606 may also include a transmit signal path, which may include circuits for up-converting baseband signals provided by the baseband circuit 610 and providing an RF output signal for transmission to the FEM circuit 608.

[0134] The receiving signal path of the RF circuit 606 includes a mixer circuit 606a, an amplifier circuit 606b, and a filter circuit 606c. In some specific implementations, the transmitting signal path of the RF circuit 606 may include a filter circuit 606c and a mixer circuit 606a. The RF circuit 606 also includes a synthesizer circuit 606d for synthesizing the frequency used by the mixer circuit 606a for the receiving signal path and the transmitting signal path. In some specific implementations, the mixer circuit 606a of the receiving signal path can be configured to down-convert the RF signal received from the FEM circuit 608 based on the synthesized frequency provided by the synthesizer circuit 606d. The amplifier circuit 606b can be configured to amplify the down-converted signal, and the filter circuit 606c can be a low-pass filter (LPF) or a band-pass filter (BPF) configured to remove unwanted signals from the down-converted signal to generate an output baseband signal. The output baseband signal can be provided to the baseband circuit 610 for further processing. In some implementations, the output baseband signal can be a zero-frequency baseband signal, but this is not required.In some implementations, the mixer circuit 606a of the receive signal path can include a passive mixer.

[0135] In some implementations, the mixer circuit 606a of the transmit signal path can be configured to up-convert an input baseband signal based on a synthesized frequency provided by the synthesizer circuit 606d to generate an RF output signal for the FEM circuit 608. The baseband signal can be provided by the baseband circuit 610 and can be filtered by the filter circuit 606c.

[0136] In some implementations, the mixer circuit 606a of the receive signal path and the mixer circuit 606a of the transmit signal path may include two or more mixers and may be arranged for orthogonal down-conversion and up-conversion, respectively. In some implementations, the mixer circuit 606a of the receive signal path and the mixer circuit 606a of the transmit signal path may include two or more mixers and may be arranged for image suppression (e.g., Hartley image suppression). In some implementations, the mixer circuit 606a of the receive signal path and the mixer circuit 606a of the transmit signal path may be arranged for direct down-conversion and direct up-conversion, respectively. In some implementations, the mixer circuit 606a of the receive signal path and the mixer circuit 606a of the transmit signal path may be configured for superheterodyne operation.

[0137] In some implementations, the output baseband signal and the input baseband signal may be analog baseband signals. In some implementations, the output baseband signal and the input baseband signal may be digital baseband signals, and the RF circuit 606 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuits, and the baseband circuit 610 may include a digital baseband interface to communicate with the RF circuit 606. In some dual-mode examples, separate radio IC circuits may be provided to process signals for each spectrum, but the techniques described herein are not limited in this regard.

[0138] In some implementations, the synthesizer circuit 606d can be a fractional-N synthesizer or a fractional N / N+1 synthesizer, although other types of frequency synthesizers can also be used. For example, the synthesizer circuit 606d can be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer including a phase-locked loop with a frequency divider.

[0139] The synthesizer circuit 606d can be configured to synthesize an output frequency based on the frequency input and the divider control input for use by the mixer circuit 606a of the RF circuit 606. In some implementations, the synthesizer circuit 606d can be a fractional-N / N+1 synthesizer.

[0140] In some implementations, the frequency input may be provided by a voltage controlled oscillator (VCO), although this is not required. The divider control input may be provided by the baseband circuit 610 or the application circuit 405 / 505 according to the desired output frequency. In some implementations, the divider control input (e.g., N) may be determined from a lookup table based on the channel indicated by the application circuit 405, 505.

[0141] The synthesizer circuit 606d of the RF circuit 606 may include a frequency divider, a delay locked loop (DLL), a multiplexer, and a phase accumulator. In some implementations, the frequency divider may be a dual-mode frequency divider (DMD), and the phase accumulator may be a digital phase accumulator (DPA). In some implementations, the DMD may be configured to divide the input signal by N or N+1 (e.g., based on a carry output) to provide a fractional frequency division ratio. In some implementations, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump, and a D-type flip-flop. The delay element may be configured to divide the VCO cycle into Nd equal phase groups, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0142] In some implementations, the synthesizer circuit 606d can be configured to generate a carrier frequency as an output frequency, while in other examples, the output frequency can be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and can be used with a quadrature generator and divider circuit to generate multiple signals with multiple different phases relative to each other at the carrier frequency. In some implementations, the output frequency can be an LO frequency (fLO). In some implementations, the RF circuit 606 can include an IQ or polarity converter.

[0143] FEM circuitry 608 may include a receive signal path that may include circuitry configured to operate on RF signals received from antenna array 611, amplify the received signals, and provide an amplified version of the received signals to RF circuitry 606 for further processing. FEM circuitry 608 may also include a transmit signal path that may include circuitry configured to amplify transmit signals provided by RF circuitry 606 for transmission by one or more antenna elements in antenna array 611. Amplification by either the transmit signal path or the receive signal path may be accomplished only in RF circuitry 606, only in FEM circuitry 608, or in both RF circuitry 606 and FEM circuitry 608.

[0144] In some implementations, the FEM circuit 608 may include a TX / RX switch to switch between transmit mode and receive mode operation. The FEM circuit 608 may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuit 608 may include an LNA to amplify a received RF signal and provide the amplified received RF signal as an output (e.g., to the RF circuit 606). The transmit signal path of the FEM circuit 608 may include a power amplifier (PA) for amplifying an input RF signal (e.g., provided by the RF circuit 606), and one or more filters for generating an RF signal for subsequent transmission by one or more antenna elements of the antenna array 611.

[0145] The antenna array 611 may include one or more antenna elements, each of which is configured to convert an electrical signal into a radio wave to travel through the air and convert the received radio wave into an electrical signal. For example, a digital baseband signal provided by the baseband circuit 610 is converted into an analog RF signal (e.g., a modulated waveform), which is amplified and transmitted using the antenna elements of the antenna array 611 including one or more antenna elements (not shown). The antenna elements may be omnidirectional, directional, or a combination thereof. The antenna elements may be formed into a variety of arrangements as known and / or discussed herein. The antenna array 611 may include a microstrip antenna or a printed antenna fabricated on the surface of one or more printed circuit boards. The antenna array 611 may be formed as a patch of metal foil of various shapes (e.g., a patch antenna) and may be coupled to the RF circuit 606 and / or the FEM circuit 608 using a metal transmission line or the like.

[0146] The processor of the application circuit 405 / 505 and the processor of the baseband circuit 610 can be used to execute elements of one or more instances of the protocol stack. For example, the processor of the baseband circuit 610 can perform layer 3, layer 2 or layer 1 functions individually or in combination, and the processor of the application circuit 405, 505 can utilize the data received from these layers (e.g., packet data) and further perform layer 4 functions (e.g., TCP and UDP layers). As mentioned herein, layer 3 may include an RRC layer, which will be described in further detail below. As mentioned herein, layer 2 may include a MAC layer, an RLC layer, and a PDCP layer, which will be described in further detail below. As mentioned herein, layer 1 may include a PHY layer of a UE / RAN node, which will be described in further detail below.

[0147] Figure 7 2 shows exemplary components of the communication circuit 700. In some implementations, the communication circuit 700 may be implemented as Figure 4 and Figure 5 The communication circuit 700 may be communicatively coupled (e.g., directly or indirectly) to one or more antennas, such as antennas 711A, 711B, 711C, and 711D. In some implementations, the communication circuit 700 includes or is communicatively coupled to dedicated receive chains, processors, or radio components, or a combination thereof, for multiple RATs (e.g., a first receive chain for LTE and a second receive chain for 5G NR). For example, Figure 7 As shown, the communication circuit 700 includes a modem 710 and a modem 720, which may correspond to or be Figure 4 and Figure 54 and 510. The modem 710 may be configured to communicate in accordance with a first RAT (such as LTE or LTE-A), and the modem 720 may be configured to communicate in accordance with a second RAT (such as 5G NR). In some implementations, the processor 705 (such as an application processor) may be connected to the modems 710, 720.

[0148] The modem 710 includes one or more processors 712 and a memory 716 in communication with the processor 712. The modem 710 is in communication with a radio frequency (RF) front end 730, which may correspond to Figure 4 and Figure 5 RFEM 415 and 515 are shown or are part thereof. RF front end 730 may include circuits for transmitting and receiving radio signals. For example, RF front end 730 includes receiving circuits (RX) 732 and transmitting circuits (TX) 734. In some specific implementations, receiving circuit 732 communicates with DL front end 752, which may include circuits for receiving radio signals from one or more antennas 711A. Transmitting circuit 734 communicates with UL front end 754, which is coupled to one or more antennas 711B.

[0149] Similarly, the modem 720 includes one or more processors 722 and a memory 726 in communication with the one or more processors 722. The modem 720 is in communication with the RF front end 740, which may correspond to Figure 4 and Figure 5 The RFEM 415 and 515 shown may be part of the RF front end 740. The RF front end 740 may include circuits for transmitting and receiving radio signals. For example, the RF front end 740 includes a receiving circuit 742 and a transmitting circuit 744. In some specific implementations, the receiving circuit 742 communicates with the DL front end 760, which may include circuits for receiving radio signals from one or more antennas 711C. The transmitting circuit 744 communicates with the UL front end 765, which is coupled to one or more antennas 711D. In some specific implementations, one or more front ends may be combined. For example, the RF switch may selectively couple the modems 710, 720 to a single UL front end 772 for transmitting radio signals using one or more antennas.

[0150] The processors 712, 722 may include one or more processing elements configured to implement the various features described herein, such as by executing program instructions stored on the memory 716, 726 (e.g., a non-transitory computer-readable memory medium). In some implementations, the processors 712, 722 may be configured as programmable hardware elements, such as FPGAs or ASICs. In some implementations, the processors 712, 722 may include one or more ICs configured to perform the functions of the processors 712, 722.

[0151] Figure 8 Various protocol functions that can be implemented in a wireless communication device are illustrated. Specifically, Figure 8 An arrangement 800 is included to illustrate the interconnection between various protocol layers / entities. Various protocol layers and entities operating in conjunction with the 5G NR system standard and the LTE system standard are provided. Figure 8 The following description, but Figure 8 Some or all aspects of the invention may also be applicable to other wireless communication network systems.

[0152] In addition to other higher layer functions not shown, the protocol layers of arrangement 800 may also include one or more of PHY 810, MAC 820, RLC 830, PDCP 840, SDAP 847, RRC 855, and NAS layer 857. These protocol layers may include one or more service access points (e.g., Figure 8 Items 859, 856, 850, 849, 845, 835, 825 and 815).

[0153] PHY 810 can transmit and receive physical layer signals 805, which can be received from or transmitted to one or more other communication devices. Physical layer signals 805 may include one or more physical channels, such as those discussed herein. PHY 810 may also perform link adaptation or adaptive modulation and coding (AMC), power control, cell search (e.g., for initial synchronization and switching purposes) and other measurement items used by higher layers (e.g., RRC 855). PHY 810 may also further perform error detection on transmission channels, forward error correction (FEC) encoding and decoding of transmission channels, modulation and demodulation of physical channels, interleaving, rate matching, mapping to physical channels, and MIMO antenna processing. In some specific implementations, an instance of PHY 810 may utilize one or more PHY-SAP 815 to process requests from an instance of MAC 820 and provide instructions thereto. According to some specific implementations, requests and instructions transmitted using PHY-SAP 815 may include one or more transmission channels.

[0154] An instance of MAC 820 may process requests from and provide indications to an instance of RLC 830 using one or more MAC-SAPs 825. These requests and indications transmitted using MAC-SAPs 825 may include one or more logical channels. MAC 820 may perform mapping between logical channels and transport channels, multiplexing MAC SDUs from one or more logical channels onto transport blocks (TBs) to be delivered to PHY 810 using transport channels, demultiplexing MAC SDUs from TBs delivered from PHY 810 using transport channels to one or more logical channels, multiplexing MAC SDUs onto TBs, scheduling information reporting, error correction through HARQ, and logical channel prioritization.

[0155] An instance of RLC 830 may process requests from an instance of PDCP 840 and provide indications thereto using one or more radio link control service access points (RLC-SAPs) 835. These requests and indications transmitted using RLC-SAPs 835 may include one or more RLC channels. RLC 830 may operate in a variety of operating modes, including: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). RLC 830 may perform transmission of upper layer protocol data units (PDUs), error correction through automatic repeat request (ARQ) for AM data transmission, and concatenation, segmentation, and reassembly of RLC SDUs for UM and AM data transmission. RLC 830 may also perform resegmentation of RLC data PDUs for AM data transmission, reorder RLC data PDUs for UM and AM data transmission, detect duplicate data for UM and AM data transmission, discard RLC SDUs for UM and AM data transmission, detect protocol errors for AM data transmission, and perform RLC re-establishment.

[0156] An instance of PDCP 840 may utilize one or more Packet Data Convergence Protocol Service Access Points (PDCP-SAP) 845 to process requests from an instance of RRC 855 or an instance of SDAP 847, or both, and provide indications thereto. These requests and indications transmitted utilizing PDCP-SAP 845 may include one or more radio bearers. PDCP 840 may perform header compression and decompression of IP data, maintain PDCP sequence numbers (SNs), perform in-order delivery of higher layer PDUs when lower layers are reestablished, eliminate duplication of lower layer SDUs when lower layers are reestablished for radio bearers mapped on RLC AM, encrypt and decrypt control plane data, perform integrity protection and integrity verification on control plane data, control timer-based data discard, and perform security operations (e.g., encryption, decryption, integrity protection, or integrity verification).

[0157] An instance of SDAP 847 may utilize one or more SDAP-SAPs 849 to process requests from one or more higher layer protocol entities and provide instructions thereto. These requests and instructions transmitted using SDAP-SAPs 849 may include one or more QoS flows. SDAP 847 may map QoS flows to data radio bearers (DRBs) and vice versa, and may also mark QoS flow identifiers (QFIs) in DL and UL packets. A single SDAP entity 847 may be configured for a separate PDU session. In the UL direction, NG-RAN 110 may control the mapping of QoS flows to DRBs in two different ways (reflective mapping or explicit mapping). For reflective mapping, SDAP 847 of UE 101 may monitor the QFI of the DL packets of each DRB, and may apply the same mapping to packets flowing in the UL direction. For DRBs, SDAP 847 of UE 101 may map UL packets belonging to a QoS flow corresponding to the QoS flow ID and PDU session observed in the DL packets of the DRB. To implement the reflective mapping, the RAN 310 may mark the DL packets with the QoS flow ID over the Uu interface. The explicit mapping may involve the RRC 855 configuring the SDAP 847 with explicit mapping rules of QoS flows to DRBs, which may be stored and followed by the SDAP 847. In some implementations, the SDAP 847 may only be used in NR implementations and may not be used in LTE implementations.

[0158] The RRC 855 may utilize one or more management service access points (M-SAPs) to configure aspects of one or more protocol layers, which may include one or more instances of PHY 810, MAC 820, RLC 830, PDCP 840, and SDAP 847. In some implementations, instances of the RRC 855 may utilize one or more RRC-SAPs 856 to process requests from and provide indications to one or more NAS entities 857. The main services and functions of the RRC 855 may include broadcasting of system information (e.g., included in a master information block (MIB) or system information block (SIB) related to NAS), broadcasting of system information related to the access stratum (AS), paging, establishment, maintenance, and release of an RRC connection between the UE 101 and the RAN 110 (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), establishment, configuration, maintenance, and release of point-to-point radio bearers, security functions including key management, inter-RAT mobility, and measurement configuration for UE measurement reporting. The MIB and SIB may include one or more information elements, each of which may include separate data fields or data structures.

[0159] NAS 857 may form the highest layer of the control plane between UE 101 and AMF 321. NAS 857 may support the mobility and session management procedures of UE 101 to establish and maintain an IP connection between UE 101 and P-GW in the LTE system.

[0160] In some implementations, one or more protocol entities of arrangement 800 may be implemented in UE 101, RAN node 111, AMF 321 in NR implementation or MME 221 in LTE implementation, UPF 302 in NR implementation or S-GW 222 and P-GW 223 in LTE implementation, etc., for control plane or user plane communication protocol stacks between the aforementioned devices. In some implementations, one or more protocol entities that may be implemented in one or more of UE 101, gNB 111, AMF 321, etc. may communicate with corresponding peer protocol entities that may be implemented in or on another device (using services of corresponding lower layer protocol entities to perform such communication). In some specific implementations, the gNB-CU of gNB 111 may host the RRC 855, SDAP 847, and PDCP 840 of the gNB that control the operation of one or more gNB-DUs, and the gNB-DUs of gNB111 may each host the RLC 830, MAC 820, and PHY 810 of gNB 111.

[0161] In some implementations, the control plane protocol stack may include, in order from the highest layer to the lowest layer, NAS 857, RRC 855, PDCP 840, RLC 830, MAC 820, and PHY 810. In this example, upper layers 860 may be built on top of NAS 857, which includes an IP layer 861, SCTP 862, and an application layer signaling protocol (AP) 863.

[0162] In some implementations such as NR implementations, AP 863 may be an NG application protocol layer (NGAP or NG-AP) 863 for the NG interface 113 defined between the NG-RAN node 111 and the AMF 321, or AP 863 may be an Xn application protocol layer (XnAP or Xn-AP) 863 for the Xn interface 112 defined between two or more RAN nodes 111.

[0163] The NG-AP 863 may support the functionality of the NG interface 113 and may include an elementary procedure (EP). The NG-AP EP may be an interaction unit between the NG-RAN node 111 and the AMF 321. The NG-AP 863 services may include two groups: UE-associated services (e.g., services related to the UE 101) and non-UE-associated services (e.g., services related to the entire NG interface instance between the NG-RAN node 111 and the AMF 321). These services may include functions such as, but not limited to: a paging function for sending a paging request to the NG-RAN node 111 involved in a specific paging area; a UE context management function for allowing the AMF 321 to establish, modify or release the UE context in the AMF 321 and the NG-RAN node 111; a mobility function for the UE 101 in CM-CONNECTED mode, for enabling intra-system HO to support mobility within the NG-RAN and inter-system HO to support mobility from / to the EPS system; a NAS signaling transport function for transmitting or rerouting NAS messages between the UE 101 and the AMF 321; a NAS node selection function for determining the association between the AMF 321 and the UE 101; an NG interface management function for setting up the NG interface and monitoring errors through the NG interface; a warning message transport function for providing a means for transmitting a warning message using the NG interface or cancelling an ongoing warning message broadcast; a configuration transport function for requesting and transmitting RAN configuration information (e.g., SON information, or performance measurement (PM) data) between two RAN nodes 111 using the CN 120; or a combination thereof, etc.

[0164] XnAP 863 may support the functionality of the Xn interface 112 and may include XnAP basic mobility procedures and XnAP global procedures. The XnAP basic mobility procedures may include procedures for handling UE mobility within the NG-RAN 111 (or E-UTRAN 210), such as handover preparation and cancellation procedures, SN state transfer procedures, UE context retrieval and UE context release procedures, RAN paging procedures, or procedures related to dual connectivity, etc. The XnAP global procedures may include procedures not related to a specific UE 101, such as Xn interface setup and reset procedures, NG-RAN update procedures, or cell activation procedures, etc.

[0165] In an LTE specific implementation, AP 863 can be an S1 application protocol layer (S1-AP) 863 for the S1 interface 113 defined between the E-UTRAN node 111 and the MME, or AP 863 can be an X2 application protocol layer (X2AP or X2-AP) 863 for the X2 interface 112 defined between two or more E-UTRAN nodes 111.

[0166] The S1 application protocol layer (S1-AP) 863 may support the functionality of the S1 interface, and similar to the NG-AP discussed previously, the S1-AP may include an S1-AP EP. The S1-AP EP may be an interaction unit between the E-UTRAN node 111 and the MME 221 within the LTE CN 120. The S1-AP 863 services may include two groups: UE-associated services and non-UE-associated services. The functions performed by these services include, but are not limited to: E-UTRAN Radio Access Bearer (E-RAB) management, UE capability indication, mobility, NAS signaling transmission, RAN Information Management (RIM), and configuration transmission.

[0167] The X2AP 863 may support the functions of the X2 interface 112 and may include an X2AP basic mobility procedure and an X2AP global procedure. The X2AP basic mobility procedure may include a procedure for handling UE mobility within the E-UTRAN 120, such as a handover preparation and cancellation procedure, an SN state transfer procedure, a UE context retrieval and a UE context release procedure, a RAN paging procedure, or a procedure related to dual connectivity, etc. The X2AP global procedure may include a procedure not related to a specific UE 101, such as an X2 interface setup and reset procedure, a load indication procedure, an error indication procedure, or a cell activation procedure, etc.

[0168] The SCTP layer (alternatively referred to as the SCTP / IP layer) 862 may provide guaranteed delivery of application layer messages (e.g., NGAP or XnAP messages in NR implementations, or S1-AP or X2AP messages in LTE implementations). The SCTP 862 may ensure reliable delivery of signaling messages between the RAN node 111 and the AMF 321 / MME 221 based in part on the IP protocol supported by the IP 861. The Internet Protocol layer (IP) 861 may be used to perform packet addressing and routing functions. In some implementations, the IP layer 861 may deliver and transmit PDUs using point-to-point transport. In this regard, the RAN node 111 may include L2 and L1 layer communication links (e.g., wired or wireless) with the MME / AMF to exchange information.

[0169] In some implementations, the user plane protocol stack may include, in order from the highest layer to the lowest layer, SDAP 847, PDCP 840, RLC 830, MAC 820, and PHY 810. The user plane protocol stack may be used for communication between UE 101, RAN node 111, and UPF 302 in NR implementations, or between S-GW 222 and P-GW 223 in LTE implementations. In this example, the upper layer 851 may be built on top of SDAP 847 and may include a user datagram protocol (UDP) and IP security layer (UDP / IP) 852, a general packet radio service (GPRS) tunneling protocol layer (GTP-U) 853 for the user plane, and a user plane PDU layer (UP PDU) 863.

[0170] The transport network layer 854 (also referred to as the "transport layer") may be built on top of the IP transport, and the GTP-U 853 may be used on top of the UDP / IP layer 852 (including the UDP layer and the IP layer) to carry the user plane PDU (UP-PDU). The IP layer (also referred to as the "Internet layer") may be used to perform packet addressing and routing functions. The IP layer may assign IP addresses to user data packets, for example, in any of the IPv4, IPv6, or PPP formats.

[0171] GTP-U 853 may be used to carry user data within the GPRS core network and between the radio access network and the core network. For example, the transmitted user data may be packets in any of the IPv4, IPv6 or PPP formats. UDP / IP 852 may provide a checksum for data integrity, a port number for addressing different functions at the source and destination, and encryption and authentication of selected data flows. The RAN node 111 and the S-GW 222 may utilize the S1-U interface to utilize a protocol stack including an L1 layer (e.g., PHY 810), an L2 layer (e.g., MAC 820, RLC 830, PDCP 840 and / or SDAP 847), a UDP / IP layer 852, and a GTP-U 853 to exchange user plane data. The S-GW 222 and the P-GW 223 may utilize an S5 / S8a interface to utilize a protocol stack including an L1 layer, an L2 layer, a UDP / IP layer 852, and a GTP-U 853 to exchange user plane data. As previously discussed, the NAS protocol may support mobility of UE 101 and session management procedures to establish and maintain an IP connection between UE 101 and P-GW 223 .

[0172] In addition, despite Figure 8 Not shown, but an application layer may exist above the AP 863 and / or transport network layer 854. The application layer may be a layer where a user of the UE 101, RAN node 111, or other network element interacts with a software application, for example, executed by the application circuitry 405 or the application circuitry 505, respectively. The application layer may also provide one or more interfaces for the software application to interact with the communication system (such as the baseband circuitry 610) of the UE 101 or RAN node 111. In some implementations, the IP layer or the application layer or both may provide functionality the same or similar to layers 5 to 7 of the Open Systems Interconnection (OSI) model, or portions thereof (e.g., OSI layer 7—application layer, OSI layer 6—presentation layer, and OSI layer 5—session layer).

[0173] NFV architecture and infrastructure can be used to virtualize one or more NFs onto physical resources including a combination of industry standard server hardware, storage hardware, or switches (alternatively performed by proprietary hardware). In other words, the NFV system can be used to perform virtual or reconfigurable implementations of one or more EPC components and functions.

[0174] Fig. 9 A block diagram of an example of a computer system including components for reading instructions from a machine-readable medium or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and performing any one or more of the techniques described herein is shown. In this example, Fig. 9A schematic diagram of hardware resources 900 is shown, including one or more processors (or processor cores) 910, one or more memory or storage devices 920, and one or more communication resources 930, each of which may be communicatively coupled using a bus 940. For specific implementations where node virtualization (e.g., NFV) is utilized, a hypervisor 902 may be executed to provide an execution environment for one or more network slices or sub-slices to utilize the hardware resources 900.

[0175] Processor 910 may include processor 912 and processor 914. Processor 910 may be, for example, a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a DSP such as a baseband processor, an ASIC, an FPGA, a radio frequency integrated circuit (RFIC), another processor (including those discussed herein), or any suitable combination thereof.

[0176] The memory / storage device 920 may include a main memory, a disk storage device, or any suitable combination thereof. The memory / storage device 920 may include, but is not limited to, any type of volatile or non-volatile memory, such as a dynamic random access memory (DRAM), a static random access memory (SRAM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a flash memory, or a solid-state storage device, or a combination thereof, etc.

[0177] The communication resources 930 may include an interconnection device or a network interface component or other suitable device to communicate with one or more peripheral devices 904 or one or more databases 906 using the network 908. For example, the communication resources 930 may include a wired communication component (e.g., for coupling using USB), a cellular communication component, an NFC component, (or Low power consumption) components, Wi-Fi components and other communication components.

[0178] The instructions 950 may include software, programs, applications, applet, applications, or other executable code for causing at least any one of the processors 910 to perform any one or more of the methods discussed herein. The instructions 950 may reside completely or partially in at least one of the processors 910 (e.g., within a cache memory of the processor), the memory / storage device 920, or any suitable combination thereof. In addition, any portion of the instructions 950 may be transmitted to the hardware resources 900 from any combination of the peripheral device 904 or the database 906. Therefore, the memory of the processor 910, the memory / storage device 920, the peripheral device 904, and the database 906 are examples of computer-readable media and machine-readable media.

[0179] The RRC state of the UE may include an idle state and a connected state. The RRC state may also include an inactive state in which the UE is registered with the network but does not actively transmit data. The connection recovery process may prepare the UE for subsequent data transmission and / or reception by causing the UE to switch from an inactive state to a connected state. In 5G NR, the RRC state of a 5G NR-enabled UE may include RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states. When no data is transmitted in the RRC_CONNECTED state, the UE may switch to the RRC_INACTIVE state but remain registered with the network. The UE may be configured for DRX operation, including for eDRX operation. In DRX, the UE may be in a DRX cycle (e.g., a sleep cycle) so that it cannot receive transmissions. In some specific implementations, the DRX cycle is 0.256 seconds. In eDRX, the DRX cycle is extended to a longer duration, such as 5.12 seconds or longer, for example, up to 44 minutes or up to 3 hours. Other time values ​​are also possible. In some specific implementations, the eDRX cycle is configurable.

[0180] When mobile terminated data arrives, the connection recovery procedure can be used to support user plane optimization for CIoT 5G when the UE supports eDRX and is in RRC_NOVATIVE state. When the UE is in eDRX and RRC_INACTIVE, the network may use one or more procedures to deliver downlink data to the UE. These procedures include a network-triggered connection recovery procedure for mobile terminated data.

[0181] Fig.10An example of a network-triggered communication process for mobile terminated data is shown. In this example, the wireless system includes a UE, a RAN, and equipment for providing AMF, SMF, UPF, and AF, respectively. Initially, the UE is unreachable for mobile terminated data because the UE is in eDRX and RRC_INACTIVE state. The UE is in a CM-CONNECTED state with the AMF. At steps 1000a, 1000b, and 1000c (collectively referred to as step 1000), the RAN, AMF, SMF, and UPF are used to provide information for subsequent downlink transmissions, such as UE notifications and / or buffer support information. At step 1000a, the RAN sends an N2 notification to the AMF. In some specific implementations, the N2 notification includes information indicating that the UE is in eDRX. In some specific implementations, the N2 notification includes buffer support information. At step 1000b, the AMF sends information to the SMF using the Nsmf_PDUSession_UpdateSMContext service, including buffer support information. At step 1000c, the SMF sends an N4 request message to the UPF and activates the extended buffer in the UPF based on the buffer support information sent by the RAN.

[0182] At step 1001, the AF sends downlink data to the UPF. At step 1002, the UPF buffers the downlink data based on information collected via step 1000c, such as buffer support information and knowing that the UE is in eDRX. Buffering the downlink data at the UPF may be advantageous because it may reduce the need for buffer space at the RAN. Buffering the downlink data at the UPF may be advantageous in the case where the UE switches RAN nodes, where the UPF may forward data to the new RAN node.

[0183] At step 1003, the UPF sends an N4 data notification message to the SMF. At step 1004, the SMF requests a UE reachability report via Namf_MT_EnableUEReachability_Request based on the N4 data notification sent from the UPF. In some implementations, the SMF may wait for the next MO data from the UE to trigger the transmission of downlink data without invoking a UE reachability report.

[0184] At step 1005, the AMF sends an N2 notification request (which includes a UE reachability information request) to the RAN. Triggering the AMF to send the N2 notification request message to obtain information about UE reachability from the RAN is based on the UE being in RRC_INACTIVE state (as notified from the RAN in step 1000) and the UE supporting eDRX (as negotiated by the network) and the arrival of DL data in step 1001.

[0185] At step 1006, the RAN sends an N2 Notification Response with the expected UE reachability information derived from the next paging moment to the AMF. The next paging moment may be based on a predetermined duration of the eDRX cycle. The N2 Notification Response may include updated buffer support information. At step 1007, the AMF sends a message to notify the SMF about the expected UE reachability information. The message may include updated buffer support information. In some specific implementations, at step 1007, the AMF notifies the SMF using a Namf_MT_EnableUEReachability_Response message. At step 1008, if necessary, the SMF sends an N4 Request message to update the UPF with the expected UE reachability information and buffer support information for the UPF downlink tunnel. At step 1009, based on the UE reachability information received in step 1008, the UPF sends the buffered data to the RAN when the expected UE is reachable.

[0186] At step 1010, the RAN performs a connection recovery procedure with the UE. An example of a connection recovery procedure is as follows: Fig.12 Other connection recovery procedures are possible. At step 1011, the RAN delivers the downlink data to the UE. At step 1012, the RAN moves the UE to the RRC_INACTIVE state after a user inactivity timeout or based on release assistance information (if available in the expected UE behavior information).

[0187] Fig.11 Another example of a network-triggered communication process for mobile terminated data is shown. In this example, the wireless system includes a UE, a RAN, and equipment for providing AMF, SMF, UPF, and AF, respectively. Initially, the UE is unreachable for mobile terminated data because the UE is in eDRX and RRC_INACTIVE state. The UE is in a CM-CONNECTED state with the AMF. At steps 1100a, 1100b, and 1100c (collectively referred to as step 1100), the RAN, AMF, SMF, and UPF are used to provide buffer support information for DL ​​transmission. At step 1100a, the RAN sends an N2 notification to the AMF. In some specific implementations, the N2 notification includes information indicating that the UE is in eDRX. In some specific implementations, the N2 notification includes buffer support information. At step 1100b, the AMF sends information to the SMF using the Nsmf_PDUSession_UpdateSMContext service, including buffer support information. At step 1100c, the SMF sends an N4 request message to the UPF and activates the extended buffer in the UPF based on the buffer support information sent by the RAN.

[0188] At step 1101, the AF sends downlink data to the UPF. At step 1102, the UPF buffers the downlink data based on the information collected via step 1100c, such as buffer support information and knowing that the UE is in eDRX. At step 1103, the UPF sends an N4 data notification message to the SMF. At step 1104, the SMF requests a UE reachability report via Namf_MT_EnableUEReachability_Request based on the N4 data notification sent from the UPF. In some specific implementations, the SMF may wait for the next MO data from the UE to trigger the sending of downlink data without invoking a UE reachability report.

[0189] At step 1105, the AMF sends an N2 notification request (which includes a UE reachability information request) to the RAN. Triggering the AMF to send the N2 notification request message to obtain information about UE reachability from the RAN is based on the UE being in RRC_INACTIVE state (as notified from the RAN in step 1100) and the UE supporting eDRX (as negotiated by the network) and the arrival of DL data in step 1101.

[0190] At step 1106, the RAN waits for the UE to become reachable. Note that the RAN is aware of the UE's eDRX cycle so that it can determine the next paging time. At step 1107, the RAN initiates RAN paging based on when the UE should be reachable according to its eDRX cycle. Note that there is no pending buffered data in the RAN at this time because the DL data is buffered at the UPF (starting from step 1102). At step 1108, the UE and RAN perform connection recovery procedures, such as Fig.12 The connection recovery process shown. At 1107, the UE responds to the RAN's paging by resuming the RRC connection and entering the RRC_CONNECTED state.

[0191] At step 1109, the RAN sends an N2 Notify Response message to the AMF, indicating that the UE is now reachable. At step 1110, based on receiving the N2 Notify Response, the AMF sends a Namf_MT_EnableUEReachability_Response to the SMF to indicate that the UE is now reachable. At step 1111, the SMF sends an N4 Request to the UPF to unlock the buffered data. At step 1112, the UPF forwards the downlink data to the RAN. At step 1113, the RAN forwards the downlink data to the UE.

[0192] Fig.12An example of a connection restoration process 1200 is shown. The connection restoration process 1200 causes the UE to transition from the RRC_INACTIVE state to the RRC_CONNECTED state. In some implementations, the trigger for process 1200 is the sending of a paging message by the RAN. Various types of triggers are possible, including those in clause 5.3.3.2.5 of 3GPP TS 23.501. At step 1201, the UE sends an RRC message containing an RRC restoration request to the RAN. In some implementations, the UE initiates a transition from the RRC_INACTIVE state to the RRC_CONNECTED state, see, for example, 3GPP TS 38.300. The RRC message may include a restoration ID associated with the UE. The UE may provide its restoration ID so that the RAN may access the stored context of the UE.

[0193] At step 1202, the RAN performs UE context retrieval, if necessary. UE context retrieval may be performed when the UE context associated with the UE attempting to restore its connection is not available locally at the accessed RAN. In some implementations, the UE context retrieval process via the radio access network is based on 3GPP TS 38.300. At step 1203, the RAN and the serving AMF may perform an N2 path switching process, if necessary. If the accessed RAN is able to retrieve the UE context, the accessed RAN node may initiate the N2 path switching process. In some implementations, the N2 path switching process includes steps 1 to 8 of clause 4.9.1.2.2 of 3GPP TS 23.502 and may include Xn data forwarding. If the connection recovery process 1200 is a response to a RAN paging triggered by the 5GC due to an N2 interface process, the RAN and the 5GC may process the N2 interface process as a conflict as described in clause 4.9.1.2 of 3GPP TS 23.502. If the AMF requests N2 notification from the RAN (see, e.g., clause 4.8.3 of 3GPP TS 23.502), the RAN may send a UE notification message to report that the UE is in RRC_CONNECTED state.

[0194] At step 1204, the RAN may send an RRC message, such as a resume response, to the UE. The RAN confirms to the UE that the UE has entered the RRC_CONNECTED state. In some implementations, steps 1203 and 1204 may be performed in parallel.

[0195] Fig.13 A flowchart showing an example of a process associated with buffering downlink data and delivering the downlink data to a UE. The process may be performed by a RAN, including by a node of the RAN such as Figure 1 RAN 110 and Figure 3At 1305, the RAN manages the UE in an eDRX and inactive state (such as an RRC_INACTIVE state). Such management may include maintaining the eDRX configuration of the UE, tracking when the UE enters an eDRX cycle, and / or determining when the UE should exit the eDRX cycle and enter an awake state. At 1310, the RAN sends a notification message to the AMF. The notification message may include information causing the UPF to buffer data for the UE. In some specific implementations, the notification message may include an indication that the UE is in an eDRX cycle and / or that the UE is in an inactive state. In some specific implementations, the notification message may include buffer support information for the UPF to buffer data for the UE.

[0196] At 1315, the RAN receives a Notification Request message from the AMF. The Notification Request message may include a request to obtain information about the reachability of the UE. In some implementations, the Notification Request message is triggered by the AF sending data for the UE to the UPF. At 1320, the RAN sends a Notification Response message to control when the UPF provides downlink data to the RAN for transmission to the UE.

[0197] At 1325, the RAN performs a connection recovery procedure with the UE to cause the UE to switch from an inactive state to a connected state. At 1330, the RAN receives downlink data from the UPF. Receiving the downlink data may include receiving the downlink data at a network interface connected to the network. At 1335, the RAN transmits the downlink data to the UE. Transmitting the downlink data to the UE may include causing the transceiver to transmit one or more signals to the UE.

[0198] In some implementations, the RAN may determine the next paging time of the UE based on the predetermined eDRX cycle duration. The RAN may generate expected UE reachability information based on the next paging time, which may be included in the notification response message sent at step 1320.

[0199] In some implementations, step 1325 may be performed before step 1320, for example, the RAN transmits a page to the UE based on the next paging time to trigger the connection recovery process, and waits to send the notification response message sent at step 1320 until after the UE has woken up. In such implementations, the notification response message may include a notification that the UE is ready to receive data.

[0200] The wireless communication system may support UEs in eDRX and RRC_INACTIVE states. The UPF may receive DL data for the UE. The AMF may send an N2 notification request to the RAN to request UE reachability information. In some specific implementations, triggering the AMF to send an N2 notification request message to obtain information about UE reachability from the RAN is based on the UE being in the RRC_INACTIVE state (as notified from the RAN) and the UE supporting eDRX (as negotiated by the network) and the arrival of DL data. The RAN may send an N2 notification response with expected UE reachability information derived from the next paging moment to the AMF. The AMF may notify the SMF of the expected UE reachability information. The SMF may send an N4 request to update the UPF with the expected UE reachability information. When the expected UE becomes reachable, the UPF may send buffered data to the RAN.

[0201] In some communication systems, the RAN may transition the eDRX-capable UE to the RRC_INACTIVE state; and may send an N2 notification to the AMF. The N2 notification may include buffer support information. The AMF may be configured to provide the buffer support information to the SMF using the Nsmf_PDUSession_UpdateSMContext service. The SMF may use one or more N4 messages and activate the extended buffer in the UPF based on the buffer information.

[0202] The UPF may send an N4 data notification message to the SMF. The SMF may send a request for a UE reachability report via the Namf_MT_EnableUEReachability service based on the N4 data notification sent from the UPF. In some implementations, the UPF sends an N4 data notification message to the SMF, and the SMF waits for the next MO data from the UE to trigger the sending of downlink data without reporting UE reachability.

[0203] The RAN may receive an N2 Notification Request from the AMF. The N2 Notification Request may include a UE reachability information request. In some implementations, triggering the AMF to send an N2 Notification Request message to obtain information about UE reachability from the RAN is based on the UE being in RRC_INACTIVE state (as notified in the N2 Notification), the UE supporting eDRX, and the arrival of DL data. The RAN may send an N2 Notification Response to the AMF. The N2 Notification Response may include expected UE reachability information derived from the next paging instant. In some implementations, the N2 Notification Response may include updated buffer support information.

[0204] The AMF may notify the SMF about the expected UE reachability information and updated buffer support information (if present in the N2 notification response). If necessary, the SMF may send an N4 request to update the UPF with the expected UE reachability information and buffer support information for the UPF downlink tunnel. When the expected UE becomes reachable based on the UE reachability information, the UPF may send the buffered data to the RAN. The RAN may perform a connection recovery procedure; transmit downlink data to the UE; and transition the UE to the RRC_INACTIVE state after detecting a user inactivity timeout or based on release assistance information (RAI) (if available in the expected UE behavior information).

[0205] In some implementations, the RAN may wait until the UE becomes reachable or in a connected state before sending an N2 notification response to the AMF. For example, the RAN may wait for the UE to become reachable; and when the UE should be reachable according to the eDRX cycle of the UE, a paging procedure with the UE may be initiated. In some implementations, there is no pending buffered data because the DL data is buffered at the UPF. The RAN may receive an RRC message from the UE in response to the paging procedure. The paging procedure may include transmitting a paging message to the UE. The RRC message may include a request to restore a previously existing RRC connection. During the connection recovery procedure, the UE enters the RRC_CONNECTED state. The RAN may send an N2 notification response to the SMF via the AMF based on the paging procedure, the N2 notification response indicating that the UE is now reachable. The SMF may send an N4 request to the UPF to unlock the buffered data. The RAN may receive downlink data from the UPF; and may forward the downlink data to the UE.

[0206] These and other techniques may be performed by an apparatus implemented or employed in one or more types of network components, user equipment, or both. In some implementations, one or more non-transitory computer-readable media include instructions for causing an electronic device to perform one or more of the techniques described herein when the instructions are executed by one or more processors of an electronic device. An apparatus may include one or more processors and one or more computer-readable media, the computer-readable media including instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more of the techniques described herein.

[0207] In different specific implementations, the methods described herein can be implemented in software, hardware, or a combination thereof. In addition, the order of the blocks of the method can be changed, and various elements can be added, reordered, combined, omitted, modified, etc. Various modifications and changes can be made, which will be apparent to those skilled in the art who benefit from this disclosure. The various specific implementations described herein are intended to be illustrative and not restrictive. Many variations, modifications, additions, and improvements are possible. Therefore, multiple examples can be provided for the components described herein as a single example. The boundaries between various components, operations, and data repositories are arbitrary to a certain extent, and specific operations are shown in the context of a specific exemplary configuration. Other allocations of functions are contemplated, and they may fall within the scope of the appended claims. Finally, the structure and function presented as discrete components in the exemplary configuration may be implemented as a combined structure or component.

[0208] The methods described herein may be implemented in a circuit, such as one or more of an integrated circuit, a logic circuit, a processor (shared, dedicated, or group) and / or a memory (shared, dedicated, or group), an application specific integrated circuit (ASIC), a field programmable device (FPD) (e.g., a field programmable gate array (FPGA), a programmable logic device (PLD), a complex PLD (CPLD), a high capacity PLD (HCPLD), a structured ASIC, or a programmable SoC), a digital signal processor (DSP), or some combination thereof. Examples of processors may include Apple A series processors, Architecture Core TM Processors, AMD processors and Qualcomm processors. Other types of processors are possible. In some specific implementations, the circuit can execute one or more software or firmware programs to provide at least some of the functions. The term "circuit" can also refer to a combination of one or more hardware elements and a program code for performing the functions of the program code (or a combination of circuits used in an electrical or electronic system). In these embodiments, the combination of hardware elements and program code can be referred to as a specific type of circuit. The circuit can also include a radio circuit, such as a transmitter, a receiver or a transceiver.

[0209] A plurality of specific implementations have been described. However, it should be understood that various modifications may be made. Elements in one or more specific implementations may be combined, deleted, modified or supplemented to form other specific implementations. As another example, the logic flow shown in the accompanying drawings does not require the specific order or sequential order shown to achieve the desired result. In addition, other steps may be provided or steps may be eliminated from the process, and other components may be added to the system or removed from the system. Therefore, other specific embodiments are within the scope of the following claims.

Claims

1. A method comprising: A user equipment UE in an extended discontinuous reception mode and in an inactive state is managed by a radio access network RAN; Sending, by the RAN, a notification message to an access and mobility management function AMF, the notification message including information causing a user plane function UPF to buffer data for the UE; receiving, by the RAN from the AMF, a notification request message including a request for obtaining information about reachability of the UE; sending, by the RAN to the AMF, a notification response message to control when the UPF provides downlink data to the RAN for transmission to the UE, wherein the notification response message includes expected UE reachability information; receiving, by the RAN from the UPF, downlink data forwarded by the UPF according to an indication by the expected UE reachability information that the UE is expected to become reachable; performing a connection recovery procedure with the UE so as to cause the UE to switch from the inactive state to a connected state; as well as The downlink data is transmitted to the UE.

2. The method according to claim 1, comprising: A next paging time of the UE is determined according to the extended discontinuous reception mode.

3. The method according to claim 2, comprising: The expected UE reachability information is generated based on the next paging moment.

4. The method according to claim 2, comprising: Transmitting a paging message to the UE based on the next paging time to trigger the connection recovery process. The method of claim 4 , wherein sending the notification response message is based on completion of the connection recovery procedure. The method of claim 4 , wherein the notification response message includes a notification that the UE is ready to receive data.

7. The method of claim 6, wherein the UPF is configured to forward the downlink data upon receiving the notification that the UE is ready to receive data.

8. The method of claim 1, wherein the notification request message is triggered by receiving data for the UE at the UPF.

9. The method of claim 1, wherein the UE is associated with a first node of the RAN before entering a sleep cycle according to the extended discontinuous reception mode, and wherein performing the connection recovery procedure comprises operating a second node of the RAN to perform the connection recovery procedure with the UE; The UPF is configured to forward the downlink data to the second node.

10. A system comprising: one or more processors; Circuitry configured to communicate with a device including user equipment UE; A circuit configured to communicate with a device, the device being configured to provide an access and mobility management function (AMF); and a memory storing instructions that, when executed by the one or more processors, cause the one or more processors to perform operations, the operations comprising: Managing UEs in extended discontinuous reception mode and inactive state; sending a notification message to the AMF, the notification message including buffer support information for a user plane function UPF to buffer data for the UE; receiving a notification request message from the AMF, the notification request message including a request to obtain information about reachability of the UE; sending a notification response message to control when the UPF provides downlink data to a radio access network RAN ​​for transmission to the UE, wherein the notification response message includes expected UE reachability information; receiving, by the RAN from the UPF, downlink data forwarded by the UPF according to an indication by the expected UE reachability information that the UE is expected to become reachable; performing a connection recovery procedure with the UE to cause the UE to switch from the inactive state to a connected state; and The downlink data is transmitted to the UE.

11. The system of claim 10, wherein the operations comprise: A next paging time of the UE is determined according to the extended discontinuous reception mode.

12. The system of claim 11, wherein the operations comprise: Expected UE reachability information is generated based on the next paging moment.

13. The system of claim 12, wherein the UPF is configured to forward the downlink data based on the expected UE reachability information.

14. The system of claim 11, wherein the operations comprise: Transmitting a paging message to the UE based on the next paging time to trigger the connection recovery process.

15. The system of claim 14, wherein sending the notification response message is based on completion of the connection recovery process.

16. The system of claim 14, wherein the notification response message includes a notification that the UE is ready to receive data.

17. The system of claim 16, wherein the UPF is configured to forward the downlink data upon receiving the notification that the UE is ready to receive data.

18. The system of claim 10, wherein the notification request message is triggered by receiving data for the UE at the UPF.

19. The system of claim 10, wherein the UE is associated with a first node of the RAN before entering a sleep period according to the extended discontinuous reception mode, and wherein performing the connection recovery procedure comprises causing a second node of the RAN to perform the connection recovery procedure with the UE; The UPF is configured to forward the downlink data to the second node.

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