Small data transmission of non-access stratum messages and uplink user data packets during radio resource control inactive state

Abstract

Aspects of the disclosure relate to providing, from a non-access stratum (NAS) layer associated with a user equipment (UE) to an access stratum (AS) layer associated with the UE, a NAS message to be transmitted to a mobility management entity via a base station when the UE is in a radio resource control (RRC) inactive state, providing, from the NAS layer, a request to resume an RRC connection, and transmitting the NAS message to the base station when the UE is in the RRC inactive state. Other aspects, embodiments, and features are also claimed and described.

Description

Technical Field

[0001] The techniques described below generally relate to wireless communication systems, and more particularly to low latency communication of non-access layer messages and uplink user data packets in inactive states.

[0002] introduction

[0003] As the demand for mobile broadband access continues to grow, research and development are constantly advancing wireless communication technologies to not only meet the growing demand for mobile broadband access, but also to improve and enhance the user experience of mobile communications.

[0004] A brief overview of some examples

[0005] The following provides a brief overview of one or more aspects of this disclosure to offer a basic understanding of such aspects. This overview is not an exhaustive summary of all contemplated features of this disclosure, nor is it intended to identify key or defining elements of all aspects of this disclosure, nor to define the scope of any or all aspects of this disclosure. Its sole purpose is to present some concepts of one or more aspects of this disclosure in a simplified form as a prelude to the more detailed description that follows.

[0006] In one example, a method for wireless communication at a user equipment is disclosed. In a more specific example, the method includes: providing a NAS message to be transmitted via a base station to a mobility management entity from a Non-Access Stratum (NAS) layer associated with the UE to an Access Stratum (AS) layer associated with the UE when the user equipment (UE) is in a Radio Resource Control (RRC) inactive state; providing a request to restore RRC connection from the NAS layer; and transmitting the NAS message to the base station when the UE is in the RRC inactive state.

[0007] In another example, a method for wireless communication at a user equipment is disclosed. In a more specific example, the method includes: when the user equipment (UE) is in a radio resource control (RRC) inactive state, enabling the transmission of uplink (UL) user data packets associated with a protocol data unit (PDU) session to a base station by a non-access stratum (NAS) layer associated with the UE; providing a request from the NAS layer to resume the radio resource control (RRC) connection; and transmitting the UL user data packets to the base station when the UE is in the RRC inactive state.

[0008] In yet another example, a method for wireless communication at a user equipment is disclosed. In a more specific example, the method includes: when the user equipment (UE) is in a Radio Resource Control (RRC) inactive state, providing a NAS message to be transmitted to a base station from a Non-Access Stratum (NAS) layer associated with the UE to an Access Stratum (AS) layer associated with the UE; providing a request to restore RRC connection from the NAS layer; receiving an indication from the AS layer to the NAS layer that the UE has transitioned to an RRC connected state; and, upon receiving the indication that the UE has transitioned to an RRC connected state, transmitting the NAS message to a mobility management entity via the NAS layer.

[0009] In yet another example, a wireless communication device is disclosed. In a more specific example, the wireless communication device includes: a transceiver; a memory; and a processor communicatively coupled to the transceiver and the memory, the processor being configured to: provide a NAS message to be transmitted via a base station to a mobility management entity from a Non-Access Stratum (NAS) layer associated with the UE to an Access Stratum (AS) layer associated with the UE when the user equipment (UE) is in a Radio Resource Control (RRC) inactive state; provide a request to restore RRC connection from the NAS layer; and transmit the NAS message to the base station via the transceiver when the UE is in the RRC inactive state.

[0010] In a further example, a wireless communication device is disclosed. In a more specific example, the wireless communication device includes: a transceiver; a memory; and a processor communicatively coupled to the transceiver and the memory, the processor being configured to: enable transmission of uplink (UL) user data packets associated with a Protocol Data Unit (PDU) session to a base station by a Non-Access Stratum (NAS) layer associated with the UE when the user equipment (UE) is in a Radio Resource Control (RRC) inactive state; provide a request from the NAS layer to resume the Radio Resource Control (RRC) connection; and transmit the UL user data packets to the base station via the transceiver when the UE is in the RRC inactive state.

[0011] In another further example, a wireless communication device is disclosed. In a more specific example, the wireless communication device includes: a transceiver; a memory; and a processor communicatively coupled to the transceiver and the memory, the processor being configured to: when a user equipment (UE) is in a Radio Resource Control (RRC) inactive state, provide a NAS message to be transmitted to a base station from a Non-Access Stratum (NAS) layer associated with the UE to an Access Stratum (AS) layer associated with the UE; provide a request to restore RRC connection from the NAS layer; receive an indication from the AS layer to the NAS layer that the UE has transitioned to an RRC connected state; and after receiving the indication that the UE has transitioned to an RRC connected state, transmit the NAS message to a mobility management entity via the NAS layer using the transceiver.

[0012] These and other aspects of the technology described herein will be more fully understood upon reading the following detailed description. Other aspects, features, and embodiments will become apparent to those skilled in the art after reading the following description of specific exemplary embodiments in conjunction with the accompanying drawings. Although the following description may discuss various advantages and features with respect to certain embodiments and drawings, all embodiments may include one or more of the advantageous features discussed herein. In other words, while this specification may discuss one or more embodiments having certain advantageous features, one or more such features may also be used according to the various embodiments discussed herein. Similarly, although this specification may discuss exemplary embodiments in the form of devices, systems, or methods, it should be understood that such exemplary embodiments may be implemented in various devices, systems, and methods. Brief description of the attached diagram

[0014] Figure 1 This is a schematic illustration of a wireless communication system based on some aspects of this disclosure.

[0015] Figure 2 This is a conceptual explanation of an example of a radio access network based on some aspects of this disclosure.

[0016] Figure 3 This is a schematic explanation of the user plane protocol stack and control plane protocol stack based on some aspects of this disclosure.

[0017] Figure 4 This is a block diagram that conceptually illustrates an example of a hardware implementation for a scheduling entity according to some aspects of this disclosure.

[0018] Figure 5 It is a block diagram that conceptually illustrates an example of a hardware implementation for a scheduled entity according to some aspects of this disclosure.

[0019] Figure 6This is a flowchart illustrating an exemplary process for transmitting NAS messages using small data transfer, according to some aspects of this disclosure.

[0020] Figure 7 This is a flowchart illustrating an exemplary process for transmitting uplink user data packets using small data transmission, according to some aspects of this disclosure.

[0021] Figure 8 This is a call flow diagram illustrating an exemplary process for transmitting NAS messages and / or uplink user data packets using small data transfer, according to some aspects of this disclosure.

[0022] Figure 9 This is a call flow diagram illustrating an exemplary process for transitioning to a NAS idle state according to some aspects of this disclosure.

[0023] Figure 10 This is another call flow diagram illustrating an exemplary process for transmitting NAS messages and / or uplink user data packets using small data transfer, according to some aspects of this disclosure.

[0024] Figure 11 This is another call flow diagram illustrating an exemplary process for transitioning to a NAS idle state according to some aspects of this disclosure.

[0025] Figure 12 This is a call flow diagram illustrating an exemplary process for transmitting NAS messages and / or uplink user data packets after determining that small data transmission is not being used, according to some aspects of this disclosure.

[0026] Detailed description

[0027] The detailed description that follows, taken in conjunction with the accompanying drawings, is intended as a description of various configurations and is not intended to represent only the configurations in which the concepts described herein can be practiced. This detailed description includes specific details to provide a thorough understanding of the various concepts. However, those skilled in the art will readily recognize that these concepts can be practiced without these specific details. In some instances, well-known structures and components are provided in the form of block diagrams in order to avoid obscuring such concepts.

[0028] While this specification describes aspects and embodiments through the explanation of some examples, those skilled in the art will understand that additional implementations and use cases may arise in many different arrangements and scenarios. The innovations described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and package arrangements. For example, the embodiments and / or devices may arise via integrated chip (IC) embodiments and other devices based on non-modular components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / shopping devices, medical devices, AI-enabled devices, etc.). While some examples may or may not be specific to particular use cases or applications, broad applicability of the described innovations can emerge. The scope of implementations can range from chip-level or modular components to non-modular, non-chip-level implementations, and further to aggregated, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described technology. In some practical settings, devices incorporating the described aspects and features may also necessarily include additional components and features for implementing and practicing the claimed and described embodiments. For example, the transmission and reception of wireless signals must include several components for analog and digital purposes (e.g., hardware components including antennas, radio frequency (RF) chains, power amplifiers, modulators, buffers, processors, interleavers, adders / summers, etc.). The techniques disclosed herein are intended to be implemented in a wide variety of devices, chip-level components, systems, distributed arrangements, end-user equipment, etc., of various sizes, shapes, and configurations.

[0029] In some aspects of this disclosure, when the scheduled device is in an RRC inactive state, the NAS layer 802 can provide an indication associated with NAS messages (e.g., via a cause value). Such a cause value can cause the AS layer 804 to use SDT to transmit NAS messages (e.g., if SDT is enabled). For example, the NAS layer 802 can be configured to determine whether to initiate the transmission of messages not exceeding a threshold size via SDT. In such examples, the NAS layer 802 can prompt the AS layer 804 to utilize an SDT session to transmit NAS messages (e.g., instead of the AS layer 804 determining whether to transmit NAS messages via SDT). The following disclosure presents various concepts that can be implemented across a wide variety of telecommunications systems, network architectures, and communication standards. Referring now... Figure 1 This illustrative illustration, by way of example and not limitation, shows various aspects of this disclosure with reference to a wireless communication system 100. The wireless communication system 100 includes several interaction domains: a core network 102, a radio access network (RAN) 104, and user equipment (UE) 106. The wireless communication system 100 enables the UE 106 to perform data communication with an external data network 110, such as (but not limited to) the Internet.

[0030] RAN 104 can implement any suitable one or more wireless communication technologies to provide radio access to UE 106. As an example, RAN 104 can operate according to the 3rd Generation Partnership Project (3GPP) New Radio (NR) specification (often referred to as 5G or 5G NR). In some examples, RAN 104 can operate under a hybrid of 5G NR and the Evolved Universal Terrestrial Radio Access Network (eUTRAN) standard (often referred to as Long Term Evolution (LTE)). 3GPP refers to this hybrid RAN as Next Generation RAN, or NG-RAN. Of course, many other examples can be utilized within the scope of this disclosure.

[0031] As explained, RAN 104 includes multiple base stations 108. Broadly speaking, a base station is a network element in a radio access network responsible for radio transmissions to and from a UE in one or more cells. In different technologies, standards, or contexts, "base station" may be referred to by those skilled in the art as a base transceiver station (BTS), radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), access point (AP), B node (NB), eNode B (eNB), gNode B (gNB), or some other suitable term.

[0032] RAN 104 supports wireless communication for multiple mobile devices. As in 3GPP standards, those skilled in the art may refer to a mobile device as a UE, but may also refer to it as a mobile station (MS), subscriber station, mobile unit, subscriber unit, radio unit, remote unit, mobile device, radio device, wireless communication device, remote device, mobile subscriber station, access terminal (AT), mobile terminal, radio terminal, remote terminal, handheld device, terminal, user agent, mobile client, client, or any other suitable term. A UE can be a device that provides access to network services. A UE can take many forms and may include a series of devices.

[0033] In this document, a “mobile” device (e.g., a UE) does not necessarily need to be mobile and may be stationary. The term mobile device or mobile equipment refers to a wide variety of devices and technologies. A UE may include several hardware structural components that are sized, shaped, and arranged to facilitate communication; such components may include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc., electrically coupled to each other. For example, some non-limiting examples of mobile devices include mobile devices, cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal computers (PCs), laptops, netbooks, smartbooks, tablets, personal digital assistants (PDAs), and a wide variety of embedded systems, such as those corresponding to the “Internet of Things” (IoT). Additionally, mobile devices can be automobiles or other transportation vehicles, remote sensors or actuators, robots or robotic equipment, satellite radios, Global Positioning System (GPS) devices, object tracking devices, drones, multi-rotor aircraft, quadcopters, remote control devices, consumer and / or wearable devices (such as glasses), wearable cameras, virtual reality devices, smartwatches, health or fitness trackers, digital audio players (e.g., MP3 players), cameras, game consoles, etc. Mobile devices can also be digital home or smart home devices, such as home audio, video and / or multimedia equipment, appliances, vending machines, smart lighting equipment, home security systems, smart meters, etc. Mobile devices can also be smart energy devices, security devices, solar panels or solar arrays, municipal infrastructure equipment controlling electricity, lighting, water, etc. (e.g., smart grids); industrial automation and enterprise equipment; logistics controllers; agricultural equipment; military defense equipment, vehicles, aircraft, ships, and weapons, etc. Furthermore, mobile devices can provide connected or telemedicine support, such as remote healthcare. Remote healthcare devices may include remote healthcare monitoring devices and remote healthcare supervision devices, whose communications may be given priority or preferential access over other types of information, for example, in the form of priority access for critical service data transmission and / or relevant QoS for critical service data transmission.

[0034] Wireless communication between RAN 104 and UE 106 can be described as utilizing an air interface. Transmissions over the air interface from a base station (e.g., base station 108) to one or more UEs (e.g., UE 106) can be referred to as downlink (DL) transmissions. According to certain aspects of this disclosure, the term downlink can refer to point-to-multipoint transmissions originating at a scheduling entity (further described below; e.g., base station 108). Another way to describe this scheme is to use the term broadcast channel multiplexing. Transmissions from a UE (e.g., UE 106) to a base station (e.g., base station 108) can be referred to as uplink (UL) transmissions. According to a further aspect of this disclosure, the term uplink can refer to point-to-point transmissions originating at a scheduled entity (further described below; e.g., UE 106).

[0035] In some examples, access to the air interface can be scheduled, where a scheduling entity (e.g., base station 108) allocates resources for communication among some or all of the equipment and devices within its service area or cell. Within this disclosure, as further described below, the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. That is, for scheduled communication, UE 106 (which may be a scheduled entity) may utilize the resources allocated by scheduling entity 108.

[0036] Base station 108 is not the only entity that can be used as a scheduling entity. That is, in some examples, a UE can be used as a scheduling entity to schedule resources for one or more scheduled entities (e.g., one or more other UEs).

[0037] like Figure 1 As explained, scheduling entity 108 may broadcast downlink traffic 112 to one or more scheduled entities 106. Broadly speaking, scheduling entity 108 is a node or device responsible for scheduling traffic (including downlink traffic 112 and, in some examples, uplink traffic 116 from one or more scheduled entities 106 to scheduling entity 108) in a wireless communication network. On the other hand, scheduled entity 106 is a node or device that receives downlink control information 114 (including, but not limited to, scheduling information (e.g., permission), synchronization or timing information), or other control information from another entity in the wireless communication network (such as scheduling entity 108).

[0038] Generally, base station 108 may include a backhaul interface for communicating with the backhaul section 120 of a wireless communication system. Backhaul 120 provides a link between base station 108 and core network 102. Furthermore, in some examples, the backhaul network provides interconnection between the respective base stations 108. Various types of backhaul interfaces can be employed, such as a direct physical connection using any suitable transport network, a virtual network, etc.

[0039] Core network 102 may be part of wireless communication system 100 and may be independent of the radio access technology used in RAN 104. In some examples, core network 102 may be configured according to 5G standards (e.g., 5GC). In other examples, core network 102 may be configured according to 4G evolved packet core (EPC) or any other suitable standard or configuration.

[0040] In some respects, one or more of the UEs 106 can transition between various connected states. For example, in an idle state (e.g., Radio Resource Control (RRC) idle state), the UE may not be registered to any particular cell and may reduce transmission and / or reception activities (e.g., by periodically monitoring paging messages and performing other operations to manage mobility). In a connected state (e.g., RRC connected state), the UE may be registered to a particular cell, and mobility may be controlled by the network. A UE in a connected state may maintain one or more active communication sessions via the network and may store access layer (AS) context (e.g., to facilitate secure communication between the UE and the base station). In an inactive state (e.g., RRC inactive state), the UE may be registered to a particular cell and may store AS context, but may reduce transmission and / or reception activities (e.g., by periodically monitoring paging messages and performing other measurements to manage mobility). However, unlike the idle state, the UE can transition from an inactive state to a connected state relatively quickly (e.g., via the Radio Access Channel (RACH) procedure). When a UE receives a hangup message from a base station, the UE can transition from a connected state to an inactive state, and can transition back to a connected state without performing a registration process.

[0041] Generally, the amount of data that can be communicated to and / or received from an inactive UE is limited. Mechanisms for Small Data Transmission (SDT) can serve as a means to facilitate the transmission of small amounts of data while the UE is inactive, which can reduce latency (e.g., by transmitting and / or receiving data without rebuilding connectivity) and / or reduce power consumption (e.g., by allowing the UE to spend more time in the inactive state). When the UE is inactive, the base station can enable the UE to communicate using an SDT session by allocating resources to the UE (e.g., resources associated with one or more Signal Radio Bearers (SRBs) and / or Data Radio Bearers (DRBs). The UE can use an SDT session not exceeding a specific size (e.g., the size allocated to the UE for transmission using SRBs and / or DRBs for SDT) to transmit and / or receive any suitable data.

[0042] Figure 2 The illustrative explanation of RAN 200 is provided as an example, not a limitation. In some examples, RAN 200 may be used in conjunction with the above description and in Figure 1 The same applies to RAN 104 as explained in the text. The geographical area covered by RAN 200 can be divided into cellular areas (cells) that can be uniquely identified by user equipment (UE) based on an identifier broadcast from an access point or base station. Figure 2 Macrocells 202, 204, and 206, and small cell 208, are described, each of which may include one or more sectors (not shown). A sector is a sub-region of a cell. All sectors within a cell are served by the same base station. Radio links within a sector may be identified by a single logical identifier belonging to that sector. In a cell divided into sectors, multiple sectors within the cell may be formed by an antenna array, where each antenna is responsible for communication with UEs in a portion of the cell.

[0043] Figure 2 Two base stations 210 and 212 in cells 202 and 204 are shown; and a third base station 214 in cell 206 controlling a remote radio head (RRH) 216 is shown. That is, the base stations may have integrated antennas, or may be connected to the antenna or RRH via a feed cable. In the illustrated example, cells 202, 204, and 206 may be referred to as macrocells because base stations 210, 212, and 214 support cells with large sizes. Furthermore, base station 218 is shown in small cell 208 (e.g., microcell, picocell, femtocell, home base station, home B-node, home evolved B-node, etc.), which may overlap with one or more macrocells. In this example, cell 208 may be referred to as a small cell because base station 218 supports cells with relatively small sizes. Cell size settings can be determined based on system design and component constraints.

[0044] RAN 200 may include any number of radio base stations and cells. Furthermore, the RAN may include relay nodes to extend the size or coverage area of ​​a given cell. Base stations 210, 212, 214, and 218 provide radio access points to the core network for any number of mobile devices. In some examples, base stations 210, 212, 214, and / or 218 may be connected to the network described above and in... Figure 1 The base station / scheduling entity 108 described in the Chinese explanation is the same.

[0045] Figure 2Further includes a quadcopter or drone 220, which can be configured to be used as a base station. That is, in some examples, the cell may not be stationary, and the geographical area of ​​the cell may move depending on the location of the mobile base station (such as the quadcopter 220).

[0046] Within RAN 200, a cell may include UEs capable of communicating with one or more sectors of each cell. Furthermore, each base station 210, 212, 214, 218, and 220 may be configured to provide all UEs in the respective cell to the core network 102 (see [link to core network 102]). Figure 1 Access points. For example, UEs 222 and 224 may communicate with base station 210; UEs 226 and 228 may communicate with base station 212; UEs 230 and 232 may communicate with base station 214 via RRH 216; UE 234 may communicate with base station 218; and UE 236 may communicate with mobile base station 220. In some examples, UEs 222, 224, 226, 228, 230, 232, 234, 236, 238, 240 and / or 242 may communicate with the access points described above and in... Figure 1 The UE / scheduled entity 106 described in the text is the same.

[0047] In some examples, a mobile network node (e.g., quadcopter 220) can be configured to act as a UE. For example, quadcopter 220 can operate within cell 202 by communicating with base station 210.

[0048] In a further aspect of RAN 200, sidelink signals can be used between UEs without relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs 226 and 228) can communicate with each other using peer-to-peer (P2P) or sidelink signal 227 without relaying the communication through a base station (e.g., base station 212). In a further example, UE 238 is described as communicating with UEs 240 and 242. Here, UE 238 can act as a scheduling entity or a primary sidelink device, and UEs 240 and 242 can act as scheduled entities or non-primary (e.g., secondary) sidelink devices. In yet another example, the UE can act as a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P), or vehicle-to-vehicle (V2V) network, and / or a mesh network. In a mesh network example, UEs 240 and 242 can optionally communicate directly with each other in addition to communicating with scheduling entity 238. Thus, in a wireless communication system with scheduled access to time-frequency resources and with cellular, P2P, or mesh configurations, a scheduling entity and one or more scheduled entities can communicate using the scheduled resources.

[0049] In radio access network 200, the ability of a UE to communicate independently of its location while on the move is referred to as mobility. Access and Mobility Management Function (AMF, not explained) Figure 1 The core network (102) can generally establish, maintain, and release various physical channels between the UE and the radio access network. The AMF may further include Security Context Management (SCMF) functions that manage the security context for both control plane and user plane functionality, and Security Anchor Function (SEAF) functions that perform authentication.

[0050] Figure 3 This is a schematic illustration of the user plane protocol stack and control plane protocol stack based on some aspects of this disclosure. In wireless telecommunications systems, the communication protocol architecture can take various forms depending on the specific application. For example, in a 3GPP NR system, the signaling protocol stack is divided into Non-Access Layer (NAS) and Access Layer (AS) layers and protocols. NAS provides the upper layer for UE106 and core network 102 (see reference). Figure 1 The AS provides lower layers for signaling between the core network 102 (e.g., 5GC) and the UE106.

[0051] Go to Figure 3 This section explains the radio protocol architecture with user plane protocols and control plane protocols (showing their corresponding stacks, such as layers or sublayers). Radio bearers between the base station and the UE can be classified into data radio bearers (DRBs) for carrying user plane data corresponding to user plane protocols; and signaling radio bearers (SRBs) for carrying control plane data corresponding to control plane protocols.

[0052] In the AS (Automatic Access Control) layer, both the user plane and control plane protocols comprise the Physical Layer (PHY), Media Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP). The PHY is the lowest layer and implements various physical layer signal processing functions. The MAC layer provides multiplexing between the logical and transport channels and is responsible for various functions. For example, the MAC layer is responsible for reporting scheduling information, priority handling and prioritization, and error correction through Hybrid Automatic Repeat Request (HARQ) operations. The RLC layer provides functions such as sequence numbering, segmentation and reassembly of upper-layer data packets, and duplicate packet detection. The PDCP layer provides functions including header compression of upper-layer data packets to reduce radio transmission overhead, security through packet encryption, and integrity protection and authentication.

[0053] In the user plane protocol stack, the Service Data Adaptation Protocol (SDAP) layer provides services and functions for maintaining the desired Quality of Service (QoS). Furthermore, in the control plane protocol stack, the Radio Resource Control (RRC) layer includes several functional entities for routing higher-layer messages, handling broadcast and paging functions, establishing and configuring radio bearers, and NAS message passing between the NAS and the UE.

[0054] The NAS protocol layer provides a wide range of control functions between UE 106 and core network 102. These functions include, for example, registration management functions, connection management functions, and user plane connection activation and deactivation.

[0055] In some aspects of this disclosure, the AS layer can transition the UE from a connected state (e.g., RRC connected) to an inactive state (e.g., RRC inactive). As described above... Figure 1 As described, the base station can enable Small Data Transmission (SDT) when the UE is in an inactive state, which can reduce latency and / or power consumption during the period when small data is to be transmitted and / or received. Without enabling SDT, the transmission and / or reception of NAS messages and / or data by the UE in an inactive state can be suppressed. For example, if the NAS layer generates a NAS message to be transmitted to the core network, the NAS layer can request the AS layer to restore connectivity, and the transmission of the NAS message can be suppressed while the UE remains in an inactive state.

[0056] In some aspects of this disclosure, the NAS layer supporting SDT and / or for a UE that has SDT enabled (e.g., by a base station) can provide NAS messages to the AS layer in conjunction with a request to restore connectivity (e.g., enabling the transmission of UL user data packets for a PDU session). The AS layer can utilize resources associated with SDT to transmit NAS messages received from the NAS layer before the UE transitions to a connected state. This can facilitate earlier communication of NAS messages and / or UL user data packets, and / or can contribute to reduced power consumption (e.g., by reducing the number of transitions to the RRC connected state).

[0057] Figure 4 This is a block diagram illustrating an example of the hardware implementation of the scheduling entity 400 using the processing system 414. For example, the scheduling entity 400 could be as follows: Figure 1 User equipment (UE) as described by any one or more of 2 and / or 2. In another example, scheduling entity 400 may be as follows: Figure 1 The base station explained in either or both of the two.

[0058] Scheduling entity 400 may include a processing system 414 having one or more processors 404. Examples of processors 404 include microprocessors, microcontrollers, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionalities described throughout this disclosure. In various examples, scheduling entity 400 may be configured to perform any or more of the functions described herein. That is, processor 400, as used in scheduling entity 404, may be configured (e.g., coordinated with memory 405) to implement the functions described below and Figure 8-12 Any one or more processes and procedures explained in the text.

[0059] Processing system 414 may be implemented with a bus architecture generally represented by bus 402. Depending on the specific application and overall design constraints of processing system 414, bus 402 may include any number of interconnect buses and bridges. Bus 402 communicatively couples together various circuits including one or more processors (generally represented by processor 404), memory 405, and computer-readable media (generally represented by computer-readable media 406). Bus 402 may also link various other circuits, such as timing sources, peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further. Bus interface 408 provides an interface between bus 402 and transceiver 410. Transceiver 410 provides a communication interface or means for communicating with various other equipment over a transmission medium. Depending on the characteristics of the equipment, user interface 412 (e.g., keypad, display, speaker, microphone, joystick) may also be provided. Of course, such user interface 412 is optional, and some examples (such as base stations) may omit such user interface.

[0060] In some aspects of this disclosure, processor 404 may include a Radio Resource Control (RRC) Connection Management Circuitry System 440 configured (e.g., coordinated with memory 405) for various functions, including, for example, managing the RRC state of one or more UEs. For example, RRC Connection Management Circuitry System 440 may be configured to implement the following regarding... Figure 8 (Including, for example, box 806); Regarding Figure 9 (Including, for example, box 922); Regarding Figure 10 (Including, for example, box 1006); Regarding Figure 11 (Including, for example, box 1124); and regarding Figure 12 (Including, for example, boxes 1206 and / or 1218) one or more functions described.

[0061] In some further aspects of this disclosure, processor 404 may include Small Data Transfer (SDT) management circuitry 442 configured (e.g., coordinated with memory 405) for various functions, including, for example, enabling an SDT session in response to a UE transitioning to an inactive state, allocating resources to the UE, etc. For example, SDT management circuitry 442 may be configured to implement the following regarding... Figure 10 (Including, for example, box 1008) one or more functions described.

[0062] Processor 404 is responsible for managing bus 402 and general processing, including the execution of software stored on computer-readable medium 406. When executed by processor 404, the software causes processing system 414 to perform various functions described below for any particular device. Processor 404 may also use computer-readable medium 406 and memory 405 to store data manipulated by processor 404 during software execution.

[0063] One or more processors 604 in the processing system can execute software. Software should be broadly interpreted as instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description languages, or other terms. The software may reside on a computer-readable medium 406. The computer-readable medium 406 may be a non-transitory computer-readable medium. As examples, non-transient computer-readable media include magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes), optical discs (e.g., compact discs (CDs) or digital multi-purpose discs (DVDs)), smart cards, flash memory devices (e.g., cards, sticks, or key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable media for storing software and / or instructions that can be accessed and read by a computer. Computer-readable medium 406 may reside in processing system 414, be external to processing system 414, or be distributed across multiple entities including processing system 414. Computer-readable medium 406 may be implemented in a computer program product. As an example, a computer program product may include a computer-readable medium in packaging material. Those skilled in the art will recognize how the functionality described throughout this disclosure is best implemented depending on the specific application and the overall design constraints imposed on the system as a whole.

[0064] In some aspects of this disclosure, computer-readable storage medium 406 may store computer-executable code including RRC connection management instructions 452, which configure scheduling entity 400 for various functions, including, for example, managing the RRC status of one or more UEs. For example, RRC connection management instructions 452 may be configured to cause scheduling entity 400 to perform the following... Figure 8 (Including, for example, box 806); Regarding Figure 9 (Including, for example, box 922); Regarding Figure 10 (Including, for example, box 1006); Regarding Figure 11 (Including, for example, box 1124); and regarding Figure 12 (Including, for example, boxes 1206 and / or 1218) one or more functions described.

[0065] In some further aspects of this disclosure, computer-readable storage medium 406 may store computer-executable code including SDT management instructions 454, which configure scheduling entity 400 for various functions, including, for example, enabling an SDT session in response to a UE transitioning to an inactive state, allocating resources for SDT to the UE, etc. For example, SDT management instructions 454 may be configured to cause scheduling entity 400 to perform the following... Figure 10 (Including, for example, box 1008) one or more functions described.

[0066] In one configuration, the device 400 for wireless communication includes means for managing RRC connections, means for enabling SDT sessions, and means for allocating resources for SDT to the UE. In one aspect, the aforementioned means may be... Figure 4 The processors 404 shown are configured to perform the functions described by the aforementioned means. Alternatively, the aforementioned means may be a circuit or any device configured to perform the functions described by the aforementioned means.

[0067] Of course, in the above example, the circuitry included in processor 404 is provided merely as an example, and other means for performing the functions described may be included within various aspects of this disclosure, including but not limited to those stored in computer-readable storage medium 406, or... Figure 1 In any other suitable device or apparatus described in either and / or 2 and utilizing, for example, the present article concerning Figures 6 to 12 Instructions for the process and / or algorithm described by any one or more of them.

[0068] Figure 5This is a conceptual diagram illustrating an example hardware implementation of an exemplary scheduled entity 500 employing processing system 514. According to various aspects of this disclosure, processing system 504 may include elements having one or more processors 504, or any portion of elements, or any combination of elements. For example, scheduled entity 500 may be as follows: Figure 1 User equipment (UE) as described by any one or more of 2.

[0069] Processing system 514 can be with Figure 4 The processing system 414 described above is essentially the same, including a bus interface 505, a bus 502, a memory 505, a processor 504, and a computer-readable medium 506. Furthermore, the scheduled entity 500 may include components similar to those described above. Figure 4 The user interfaces and transceivers described herein are substantially similar to those in user interface 512 and transceiver 510. That is, processor 504, as used in the scheduled entity 500, can be configured (e.g., coordinated with memory 505) to implement the following and Figures 6 to 12 One or more of the processes in which the explanation is conducted.

[0070] In some aspects of this disclosure, processor 504 may include an Access Layer (AS) management circuitry 540 configured (e.g., coordinated with memory 505) for various functions, including, for example, providing indications regarding AS layer support and / or implementation of data transfer when scheduled entity 500 is in an inactive state (e.g., indications regarding AS layer support for SDT), providing indications regarding whether the AS layer is transmitting data when scheduled entity 500 is in an inactive state (e.g., whether the AS layer is using SDT), and providing indications regarding receiving messages and / or other information from the NAS layer, and that the state of scheduled entity 500 has changed (e.g., from RRC connected to RRC inactive, from RRC inactive to RRC connected, etc.). For example, AS layer management circuitry 540 may be configured to implement the following regarding... Figure 6 (Including, for example, box 606); Regarding Figure 7 (Including, for example, box 706); Regarding Figure 8 (Including, for example, boxes 806, 808, 816 and / or 818); Regarding Figure 9 (Including, for example, boxes 910, 916 and / or 920); Regarding Figure 10 (Including, for example, boxes 1006, 1010, 1018 and / or 1020); Regarding Figure 11 (Including, for example, boxes 1106, 1116 and / or 1122); Regarding Figure 12 (Including, for example, one or more functions described in boxes 1206, 1214, 1216, 1220, 1222 and / or 1224)

[0071] In some further aspects of this disclosure, processor 504 may include a Non-Access Stratum (NAS) layer management circuitry 542 configured (e.g., coordinated with memory 505) for various functions, including, for example, providing NAS messages to the AS layer, providing requests to restore connectivity (e.g., RRC connectivity), providing requests to the AS layer to indicate whether the AS layer supports and / or implements data transfer when the scheduled entity 500 is in an inactive state, and receiving indications regarding AS layer support and / or implementation of data transfer when the scheduled entity 500 is in an inactive state (e.g., regarding AS layer support). The system receives an indication from the AS layer (e.g., whether the AS layer is using SDT) regarding whether the AS layer is transmitting data when the scheduled entity 500 is in an inactive state. It also determines that a procedure causing the transmission of NAS messages and / or uplink (UL) user data packets has been triggered. Furthermore, it receives an indication from the AS layer that the state of the scheduled entity 500 has changed (e.g., from RRC connected to RRC inactive, from RRC inactive to RRC connected, etc.), and receives messages and / or other information from the NAS layer to determine whether the NAS layer needs to transition to an idle state (e.g., 5G Mobility Management (5GMM) idle mode). For example, the AS layer management circuitry 540 can be configured to implement the following regarding... Figure 6 (Including, for example, boxes 602 and / or 604); Regarding Figure 7 (Including, for example, boxes 702 and / or 704); Regarding Figure 8 (Including, for example, boxes 810, 812 and / or 814); Regarding Figure 9 (Including, for example, boxes 906, 908, 912, 914 and / or 918); Regarding Figure 10 (Including, for example, boxes 1012, 1014 and / or 1016); Regarding Figure 11 (Including, for example, boxes 1108, 1110, 1112, 1114, 1118 and / or 1120); Regarding Figure 12 (Including, for example, one or more functions described in boxes 1208, 1210, 1212 and / or 1222)

[0072] In some aspects of this disclosure, computer-readable storage medium 506 may store computer-executable code including AS layer management instructions 552, which configure the scheduled entity 500 for various functions, including, for example, providing indications regarding AS layer support and / or implementation of data transmission when the scheduled entity 500 is in an inactive state (e.g., indications regarding AS layer support for SDT), providing indications regarding whether the AS layer is transmitting data when the scheduled entity 500 is in an inactive state (e.g., whether the AS layer is using SDT), providing indications regarding a change in the state of the scheduled entity 500 (e.g., from RRC connected to RRC inactive, from RRC inactive to RRC connected, etc.), and receiving messages and / or other information from the NAS layer. For example, AS layer management instructions 552 may be configured to cause the scheduled entity 500 to perform the following regarding Figure 6 (Including, for example, box 606); Regarding Figure 7 (Including, for example, box 706); Regarding Figure 8 (Including, for example, boxes 806, 808, 816 and / or 818); Regarding Figure 9 (Including, for example, boxes 910, 916 and / or 920); Regarding Figure 10 (Including, for example, boxes 1006, 1010, 1018 and / or 1020); Regarding Figure 11 (Including, for example, boxes 1106, 1116 and / or 1122); Regarding Figure 12 (Including, for example, the functions described in boxes 1206, 1214, 1216, 1220, 1222 and / or 1224) One or more functions. AS layer management instruction 552 may be further configured to cause the scheduled entity 500 to implement an AS layer management module configured to perform one or more of the aforementioned functions.

[0073] In some further aspects of this disclosure, the computer-readable storage medium 506 may store computer-executable code including NAS layer management instructions 554, which configure the scheduled entity 500 for various functions, including, for example, providing NAS messages to the AS layer, providing a request to restore connectivity (e.g., RRC connectivity), providing a request to the AS layer to indicate whether the AS layer supports and / or implements data transmission when the scheduled entity 500 is in an inactive state, and receiving an indication of whether the AS layer supports and / or implements data transmission when the scheduled entity 500 is in an inactive state (e.g., turning off...). The system receives an indication from the AS layer that the AS layer is transmitting data when the scheduled entity 500 is in an inactive state (e.g., whether the AS layer is using SDT), determines that a procedure causing the transmission of NAS messages and / or uplink (UL) user data packets has been triggered, receives an indication from the AS layer that the state of the scheduled entity 500 has changed (e.g., from RRC connected to RRC inactive, from RRC inactive to RRC connected, etc.), receives messages and / or other information from the NAS layer, and determines that the NAS layer needs to transition to an idle state (e.g., 5G Mobility Management (5GMM) idle mode). For example, the NAS layer management instruction 554 can be configured to cause the scheduled entity 500 to implement the following regarding... Figure 6 (Including, for example, boxes 602 and / or 604); Regarding Figure 7 (Including, for example, boxes 702 and / or 704); Regarding Figure 8 (Including, for example, boxes 810, 812 and / or 814); Regarding Figure 9 (Including, for example, boxes 906, 908, 912, 914 and / or 918); Regarding Figure 10 (Including, for example, boxes 1012, 1014 and / or 1016); Regarding Figure 11 (Including, for example, boxes 1108, 1110, 1112, 1114, 1118 and / or 1120); Regarding Figure 12 (Including, for example, boxes 1208, 1210 and / or 1222) one or more functions described. The NAS layer management instruction 554 may be further configured to cause the scheduled entity 500 to implement a NAS layer management module configured to perform one or more of the aforementioned functions.

[0074] In one configuration, the device 500 for wireless communication includes: means for providing a NAS message to be transmitted to a mobility management entity via a base station; means for providing a request to restore RRC connection; means for transmitting the NAS message and / or UL user data packets to the base station when the UE is in an RRC inactive state; means for receiving an indication that the AS layer supports data transmission when the UE is in an RRC inactive state; means for providing a request indicating whether the AS layer supports data transmission when the UE is in an RRC inactive state; means for determining that a procedure causing the transmission of the NAS message has been triggered, thereby providing the NAS message to be transmitted to the base station to the AS layer; means for determining that the NAS layer needs to transition to an idle state; means for providing a request indicating whether the AS layer is transmitting data when the UE is in an RRC inactive state; means for receiving an indication that the AS layer is transmitting data when the UE is in an RRC inactive state; and means for receiving an indication regarding... The apparatus includes: an indication that the AS layer is not transmitting data when the UE is in an RRC inactive state; an apparatus for receiving a downlink NAS message when the UE is in an RRC inactive state; an apparatus for performing NAS procedures based on the downlink NAS message when the UE remains in an RRC inactive state; an apparatus for receiving an indication regarding data transmission when the UE is in an RRC inactive state; an apparatus for receiving an indication regarding data transmission being active when the UE is in an RRC inactive state; an apparatus for receiving an indication regarding data transmission being inactive when the UE is in an RRC inactive state; an apparatus for determining whether data transmission is inactive when the UE is in an RRC inactive state; an apparatus for providing a cause value associated with a request to transmit a NAS message when the UE is in an RRC inactive state; and / or an apparatus for providing an indication regarding the expectation of a single uplink in conjunction with the NAS message; and an apparatus for providing an indication regarding the expectation of subsequent downlink messages. In one aspect, the aforementioned apparatus may be... Figure 5 The processors 504 shown are configured to perform the functions described by the aforementioned means. Alternatively, the aforementioned means may be a circuit or any device configured to perform the functions described by the aforementioned means.

[0075] Of course, in the above example, the circuitry included in processor 504 is provided merely as an example, and other means for performing the functions described may be included within various aspects of this disclosure, including but not limited to those stored in computer-readable storage medium 506, or... Figure 1 In any other suitable device or apparatus described in either and / or 2 and utilizing, for example, the present article concerning Figure 6 , 7 Instructions for the processes and / or algorithms described in 1, 8, 9, 10, 11 and / or 12.

[0076] Figure 6 This is a flowchart illustrating an exemplary process 600 for transmitting NAS messages using small data transfer according to some aspects of this disclosure. As described below, some or all of the described features may be omitted in a particular implementation within the scope of this disclosure, and some described features are not required to be used in implementing all embodiments. In some examples, Figure 6 The process explained in the text can be derived from Figure 5 The scheduled entity 500, as explained in the text, is to be executed. In some examples, Figure 6 The process can be performed by any suitable equipment or device for performing the functions or algorithms described below.

[0077] In some aspects of this disclosure, the scheduled device (e.g., UE 106, scheduled entity 500) can at 602 provide Non-Access Stratum (NAS) messages to be transmitted via the scheduling device (e.g., base station 108) to the Mobility Management Function (AMF) (or other Mobility Management Entity (MME)) within the core network 102. For example, when the scheduled device is in a Radio Resource Control (RRC) inactive state, the scheduled device can provide NAS messages from the NAS layer associated with the scheduled device to the Access Stratum (AS) layer associated with the scheduled device. As combined below Figure 8 As described, when a scheduled device is in an RRC inactive state, the scheduled entity can provide NAS messages from the NAS layer to the AS layer, and the AS layer supports small data transfers. In some aspects of this disclosure, providing NAS messages to the AS layer when the scheduled device is in an RRC inactive state can facilitate the use of small data transfer sessions to transmit NAS messages to the AMF before the RRC connection is restored. This can reduce the waiting time for NAS messages.

[0078] In some aspects of this disclosure, the scheduled device may use any suitable technology or combination of technologies to provide NAS messages to the AS layer. For example, the NAS layer may be associated with NAS management circuitry (e.g., implemented by processor 504) and / or NAS management instructions (e.g., stored using computer-readable medium 506) that cause the NAS management module to be executed, which may enable NAS messages to be provided to the AS management circuitry (e.g., implemented by processor 504) and / or the AS management module that executes based on the AS management instructions (e.g., stored using computer-readable medium 506). In some aspects of this disclosure, the NAS management circuitry and / or the NAS management module may pass NAS messages to the AS layer along with a request to transition to an RRC connected state. For example, the NAS management circuitry and / or the NAS management module may pass NAS messages concurrently with an RRC recovery request. As another example, the NAS management circuitry and / or the NAS management module may pass NAS messages as part of the payload of an RRC recovery request. In some aspects of this disclosure, NAS messages provided from the NAS layer to the AS layer for transitioning to an RRC connected state may be referred to as uplink NAS messages or uplink NAS signaling. In some aspects of this disclosure, NAS messages may include any suitable information (e.g., in addition to a request to restore an RRC connection), such as the reason for RRC restoration, access category, and access identity.

[0079] In some aspects of this disclosure, the scheduled device can provide a request to the AS from the NAS to restore the RRC connection at step 604. For example, the scheduled device can request the AS to transition to an RRC connected state. In some aspects of this disclosure, providing such an RRC restoration request to the AS can facilitate the restoration of the RRC connection for NAS message transmission in cases where the AS does not transmit NAS messages via an SDT session. This can provide a mechanism for transmitting NAS messages regardless of whether the AS layer transmits the message via SDT, thereby facilitating SDT operation transparent to the NAS layer (e.g., the NAS layer can operate without knowing whether the NAS message should be transmitted via SDT).

[0080] In some aspects of this disclosure, the scheduled device may use any suitable technology or combination of technologies to provide RRC recovery requests to the AS layer. For example, NAS management circuitry and / or NAS management modules may enable RRC recovery requests to be provided to AS management circuitry and / or AS management modules.

[0081] In some aspects of this disclosure, at 606, when the scheduled device is in an RRC inactive state, the scheduled device can transmit a NAS message to the base station. For example, the scheduled device can use resources configured for Small Data Transmission (SDT) to transmit the NAS message. In a specific example, the scheduled device can transmit the NAS message in conjunction with MSG3 (e.g., RRC Connection Request) of a 4-step Radio Access Channel (RACH) procedure. As another more specific example, the scheduled device can transmit the NAS message in conjunction with MSGA (e.g., RRC Connection Request) of a 2-step RACH procedure. The NAS message can be included as at least a portion of the MSGA payload. As yet another more specific example, the scheduled device can use UL time slots assigned to the scheduled device via a no-permission scheduling procedure to transmit the NAS message (sometimes referred to as configured-permission and no-permission transmission).

[0082] In some aspects of this disclosure, the scheduled device may include any suitable information and / or content in the message. For example, the scheduled device may transmit Shared Control Channel (CCH) messages and NAS messages.

[0083] In some aspects of this disclosure, the scheduled device may use any suitable communication interface (such as a transceiver (e.g., transceiver 510)) to transmit NAS messages and / or any other suitable data. In some aspects, the scheduled device may use any suitable signaling radio bearer (SRB), such as SRB1 and / or SRB2. Additionally or alternatively, the scheduled device may use a suitable data radio bearer (DRB) to transmit NAS messages and / or any suitable data via small data transfer. In some aspects of this disclosure, transmitting NAS messages when the scheduled device is in an RRC inactive state can facilitate earlier transmission of NAS messages to the AMF (e.g., using a small data transfer session before the RRC connection is restored). This can reduce the latency of NAS messages.

[0084] Figure 7 This is a flowchart illustrating an exemplary process for transmitting uplink user data packets using small data transmission according to some aspects of this disclosure. As described below, some or all of the described features may be omitted in a particular implementation within the scope of this disclosure, and some described features are not required to be used in implementing all embodiments. In some examples, Figure 7 The process explained in the text can be derived from Figure 5 The scheduled entity 500, as explained in the text, is to be executed. In some examples, Figure 7 The process can be performed by any suitable equipment or device for performing the functions or algorithms described below.

[0085] In some aspects of this disclosure, the scheduled device (e.g., UE 106, scheduled entity 500) can enable uplink (UL) user data packets associated with a protocol data element to be transmitted to the scheduling device (e.g., base station 108) at 702. For example, the NAS layer associated with the scheduled device can enable the transmission of UL user data packets via the AS layer associated with the scheduled device when the scheduled device is in an RRC inactive state. As combined below Figure 10 As described, when the scheduled device is in an RRC inactive state, the scheduled entity can transmit UL user data packets, enabling the AS layer to use small data transmission. In some aspects of this disclosure, transmitting UL user data packets when the scheduled device is in an RRC inactive state facilitates the use of small data transmission sessions to send UL user data packets to the scheduling entity before the RRC connection is restored. This can reduce the waiting time for UL user data packets.

[0086] In some aspects of this disclosure, the scheduled device may use any suitable technology or combination of technologies to implement the transmission of UL user data packets. For example, the NAS layer may be associated with NAS management circuitry (e.g., implemented by processor 504) and / or NAS management instructions (e.g., stored using computer-readable medium 506) that cause the NAS management module to be executed, which may enable the transmission of UL user data packets via AS management circuitry (e.g., implemented by processor 504) and / or AS management modules executed based on AS management instructions (e.g., stored using computer-readable medium 506).

[0087] In some aspects of this disclosure, the scheduled device can provide a request from the NAS to the AS to restore the RRC connection at 704. For example, the scheduled device can request the AS to transition to an RRC connected state. In some aspects of this disclosure, providing such an RRC restoration request to the AS can facilitate the restoration of the RRC connection for the transmission of UL user data packets in cases where the AS does not transmit UL user data packets via an SDT session. This can provide a mechanism for transmitting UL user data packets regardless of whether the AS layer transmits the packets via SDT, thereby facilitating SDT operation transparent to the NAS layer (e.g., the NAS layer can operate without knowing whether UL user data packets should be transmitted via SDT).

[0088] In some aspects of this disclosure, the scheduled device may use any suitable technology or combination of technologies to provide RRC recovery requests to the AS layer. For example, NAS management circuitry and / or NAS management modules may enable RRC recovery requests to be provided to AS management circuitry and / or AS management modules.

[0089] In some aspects of this disclosure, at 706, when the scheduled device is in an RRC inactive state, the scheduled device can transmit UL user data packets to the base station. For example, the scheduled device can use resources configured for Small Data Transmission (SDT) to transmit UL user data packets. In a specific example, the scheduled device can transmit UL user data packets in conjunction with MSG3 (e.g., RRC Connection Request) of a 4-step Radio Access Channel (RACH) procedure. As another more specific example, the scheduled device can transmit at least a portion of the UL user data packets in conjunction with MSGA (e.g., RRC Connection Request) of a 2-step RACH procedure. At least a portion of the UL user data packets can be included as at least a portion of the payload of the MSGA. As yet another more specific example, the scheduled device can use UL time slots assigned to the scheduled device via a no-permission scheduling procedure to transmit UL user data packets.

[0090] In some aspects of this disclosure, the scheduled device may include any suitable information and / or content in the message. For example, the scheduled device may transmit a Common Control Channel (CCH) message as well as at least a portion of UL user data packets.

[0091] In some aspects of this disclosure, the dispatched device may use any suitable communication interface (such as a transceiver (e.g., transceiver 510)) to transmit UL user data packets and / or any other suitable data. In some aspects, the dispatched device may use any suitable data radio bearer (DRB) to transmit UL user data packets and / or any suitable data via small data transmission.

[0092] Figure 8 This is a call flow diagram illustrating an exemplary process for transmitting NAS messages and / or uplink user data packets using small data transfer, according to some aspects of this disclosure. As described below, some or all of the described features may be omitted in a particular implementation within the scope of this disclosure, and some described features are not required to be used in implementing all embodiments. In some examples, Figure 8 The process can be made by Figure 5 The dispatched devices 500 and / or Figure 4 The scheduling device 400 is executed. In some examples, Figure 8 The process can be performed by any suitable equipment or device for performing the functions or algorithms described below. In a more specific example, Figure 8At least a portion of the process can be performed by the Non-Access Layer (NAS) layer 802 and / or the Access Layer (AS) layer 804. In such examples, operations associated with NAS layer 802 can be performed by NAS management circuitry (e.g., implemented by processor 504) and / or by a NAS management module that executes based on NAS management instructions (e.g., using computer-readable medium 506 for storage). Operations associated with AS layer 804 can be performed by AS management circuitry (e.g., implemented by processor 504) and / or by an AS management module that executes based on AS management instructions (e.g., using computer-readable medium 506 for storage).

[0093] At 806, the AS layer 804 associated with the scheduled entity (e.g., UE 106, scheduled entity 500) can provide the NAS layer 802 with an indication that the RRC connection is being suspended and / or has been suspended. In some aspects, the AS layer can suspend the RRC connection in response to any appropriate instruction to suspend the RRC connection (such as an instruction from a scheduling device (e.g., base station 108, scheduling device 400)).

[0094] In some aspects of this disclosure, the indication provided at 806 regarding an RRC connection being and / or being suspended can indicate that the scheduled device is transitioning (or has transitioned) from an RRC connected state to an RRC inactive state (e.g., in response to an RRC release from the scheduling device 400).

[0095] In some embodiments, NAS layer 802 may transition from 5G Mobility Management (5GMM) connectivity mode to 5GMM connectivity mode with RRC inactivity indication based on an indication provided at 806 (e.g., in response to the indication).

[0096] At 808, AS layer 804 can provide indications about AS layer 804's support for Small Data Transfer (SDT), which can be configured to transfer a relatively small amount of data during RRC inactive states.

[0097] In some aspects of this disclosure, AS layer 804 may use any suitable technique or combination of techniques to provide an indication of SDT support. For example, AS layer may set specific bits in a message conveying the pending status of an RRC connection to indicate whether SDT is supported (e.g., 1 to indicate SDT support and 0 to indicate SDT not supported, and vice versa).

[0098] At 810, NAS layer 802 may receive a trigger that causes the NAS layer to request the restoration of the RRC connection. In some aspects of this disclosure, any suitable trigger may cause the NAS layer to request the restoration of the RRC connection. For example, NAS layer 802 may generate a NAS message to be provided to the Mobility Management Function (AMF). In a more specific example, NAS layer 802 may generate a NAS message carrying location information from an upper layer and may attempt to send that location information to the AMF via the NAS message. As another example, NAS layer 802 may receive (e.g., from an upper layer, such as an application layer or connection management layer in the operating system of the scheduled device) an indication that uplink (UL) user data packets are to be transmitted to a destination (e.g., via scheduling device 400). In some aspects, NAS layer 802 may receive a trigger at 810 at any suitable time after the RRC connection is suspended and restored (or transitions to an RRC idle state).

[0099] At 812, NAS layer 802 can send a request to AS layer to restore RRC connection. For example, a scheduled device can request AS to transition to RRC connected state in response to a trigger received at 810. In some aspects of this disclosure, sending such an RRC restoration request from NAS layer 802 to AS layer 804 can facilitate the restoration of RRC connection for the transmission of NAS messages and / or UL user data packets if AS layer 804 determines that SDT will not be used to transmit NAS messages and / or UL user data packets. This can provide a mechanism for transmitting NAS messages regardless of whether AS layer transmits NAS messages and / or UL user data packets via SDT, thereby facilitating SDT operation transparent to NAS layer (e.g., NAS layer can operate without knowing whether NAS messages or UL user data packets should be transmitted via SDT).

[0100] In some aspects of this disclosure, the scheduled device 400 may use any suitable technology or combination of technologies to provide the RRC recovery request to the AS layer. For example, the NAS layer 802 may enable the RRC recovery request to be provided to the AS layer 804.

[0101] At 814, the NAS layer can send NAS messages to be transmitted and / or enable the AS layer to transmit UL user data packets for the PDU. In some aspects of this disclosure, NAS layer 802 can use any suitable technology or combination of technologies to provide the NAS messages to be transmitted and / or enable the transmission of UL user data packets to AS layer 804. For example, NAS layer 802 can pass NAS messages within the body of an RRC recovery request sent at 812. As another example, NAS layer 802 can transmit NAS messages as separate messages. As yet another example, NAS layer 802 can implement the transmission of UL user data packets.

[0102] Alternatively, in some aspects of this disclosure, if AS layer 804 does not indicate support for SDT (and / or explicitly indicates that SDT is not supported), NAS layer 802 may wait to send a NAS message to AS layer 804 until AS layer 804 indicates to NAS layer 802 that the scheduled device is in RRC connected state. For example, if AS layer 804 indicates that SDT is not supported (e.g., explicitly or by omission), NAS layer 802 may send an RRC recovery request at 812, and may omit sending a NAS message at 814 in conjunction with the RRC recovery request. In such an example, AS layer 804 may transmit the RRC recovery request to the network. After the scheduled device moves to RRC connected state, AS layer 804 may indicate to NAS layer 802 that the scheduled device is in RRC connected state, and in response, NAS layer 802 may pass a NAS message to AS layer 804.

[0103] At 816, AS layer 804 can use any suitable technique or combination of techniques to determine whether to use a Small Data Transfer (SDT) session to transmit NAS messages and / or UL user data packets. For example, AS layer 804 can determine whether to transmit NAS messages and / or UL user data packets based on the size of the packets. In such an example, if the NAS messages and / or UL user data packets are below a threshold size, AS layer 804 can determine to use an SDT session to transmit the packets. As another example, AS layer 804 can determine whether to transmit NAS messages and / or UL user data packets based on an indication from NAS layer 802 regarding whether to transmit and / or receive additional data. In some respects, the SDT threshold size can be configured by the scheduling device (e.g., in conjunction with a scheduled device transitioning from RRC connectivity to RRC inactivity). Alternatively, the SDT threshold size can be predefined in the standard.

[0104] In some aspects of this disclosure, when the scheduled device is in an RRC inactive state, NAS layer 802 can provide an indication associated with NAS messages (e.g., via a cause value). Such a cause value can cause AS layer 804 to use SDT to deliver NAS messages (e.g., if SDT is enabled). For example, NAS layer 802 can be configured to determine whether to deliver messages not exceeding a threshold size via SDT. In such examples, NAS layer 802 can prompt AS layer 804 to utilize an SDT session to deliver NAS messages (e.g., instead of AS layer 804 determining whether to deliver NAS messages via SDT).

[0105] At 818, if AS layer 804 determines that an SDT session should be used to transmit NAS messages and / or UL data packets, AS layer 804 may transmit NAS messages and / or UL user data packets to scheduling entity 400 in the SDT session.

[0106] In some aspects of this disclosure, the scheduled device may use any suitable communication interface (such as a transceiver (e.g., transceiver 510)) to transmit NAS messages, at least a portion of UL user data packets, and / or any other suitable data. In some aspects, the scheduled device 500 may use any suitable signaling radio bearer (SRB) (such as SRB1 and / or SRB2) to transmit NAS messages. Additionally or alternatively, the scheduled device 500 may use one or more suitable data radio bearers (DRBs) to transmit at least a portion of UL user data packets and / or any other suitable data via an SDT session. In some aspects of this disclosure, transmitting NAS messages and / or at least a portion of UL user data packets when the scheduled device is in an RRC inactive state may facilitate earlier transmission of at least a portion of NAS messages and / or UL user data packets to the AMF (e.g., via the scheduling device 400 to the destination). This may reduce the latency of NAS messages and / or UL user data packets.

[0107] In some aspects of this disclosure, the scheduled device 500 may include any suitable information and / or content in the message. For example, the scheduled device may transmit shared control channel (CCH) messages and NAS messages.

[0108] At 820, the scheduling device 400 can receive at least a portion of NAS messages and / or UL user data packets transmitted using resources (e.g., one or more resource blocks) configured for SDT. For example, the scheduling device 400 can configure specific resources to be used for an SDT session and can transmit an indication of which resources(s) should be used to transmit data in the SDT session.

[0109] In some aspects of this disclosure, the scheduling device 400 may further use any suitable technology or combination of technologies to process NAS messages and / or UL user data packets. For example, the scheduling device 400 may transmit a NAS message to the AMF as if the NAS message were received from the NAS layer during an RRC connected state (e.g., rather than during an SDT transmission from the AS layer during an RRC inactive state). As another example, the scheduling device 400 may cause UL data packets to be transmitted to the destination associated with the UL user data packets.

[0110] In some aspects of this disclosure, the AS layer can transmit any suitable number of SDT messages during an SDT session without transitioning to an RRC connection.

[0111] Figure 9 This is a call flow diagram illustrating an exemplary process for transitioning to a NAS idle state according to some aspects of this disclosure. As described below, some or all of the described features may be omitted in a particular implementation within the scope of this disclosure, and some described features are not required to be used in implementing all embodiments. In some examples, Figure 9 The process can be made by Figure 5 The dispatched devices 500 and / or Figure 4 The scheduling device 400 is executed. In some examples, Figure 9 The process can be performed by any suitable equipment or device for performing the functions or algorithms described below. In a more specific example, Figure 9 At least a portion of the process can be performed by the Non-Access Layer (NAS) layer 902 and / or the Access Layer (AS) layer 904. In such examples, operations associated with NAS layer 902 can be performed by NAS management circuitry (e.g., implemented by processor 504) and / or by a NAS management module that executes based on NAS management instructions (e.g., using computer-readable media 506 for storage). Operations associated with AS layer 904 can be performed by AS management circuitry (e.g., implemented by processor 504) and / or by an AS management module that executes based on AS management instructions (e.g., using computer-readable media 506 for storage).

[0112] At 906, the NAS layer 902 associated with the scheduled entity (e.g., UE 106, scheduled entity 500) can determine that the NAS layer 902 should (or must) transition to an idle state (e.g., 5GMM idle mode). In some aspects of this disclosure, the NAS layer 902 should transition to idle mode in response to any suitable conditions and / or any other suitable reason. For example, the NAS layer 902 can receive a trigger to send a registration request message to initiate a registration procedure for mobility and / or periodic registration. In a more specific example, the NAS layer 902 can receive a trigger to send a registration request message in which the NG-RAN-RCU bit of the 5GS update type IE is set to "UE radio capability update required" (e.g., as described in 3GPP TS 24.501 Release 15).

[0113] At 908, NAS layer 902 can send a request to AS layer 904 to request the status of a Small Data Transfer (SDT) session. In some aspects of this disclosure, NAS layer 902 can use any suitable technology or combination of technologies to send the request. For example, NAS layer 902 can request the status of an SDT session flag. As another example, NAS layer 902 can send a query to AS layer 904 regarding the status of the SDT session.

[0114] At 910, AS layer 904 can use any suitable technique or combination of techniques to indicate that an SDT session is in progress. For example, AS layer can respond to a request from NAS at 908 with an indication that an SDT session flag is set to a specific value (e.g., 1 to indicate that SDT is in progress and 0 to indicate that SDT is not in progress, or vice versa).

[0115] At 912, NAS layer 902 can wait for a predetermined amount of time for an ongoing SDT session to end (e.g., based on an indication sent at 910 that an SDT session is in progress).

[0116] At 914, NAS layer 902 may send another request to AS layer 904 to request the status of the SDT session (e.g., after a predetermined amount of time has elapsed). Additionally or alternatively, NAS layer 902 may wait for a response from AS layer 904 (e.g., an indication at 910 that the SDT session is in progress), and if no response is received, NAS layer 902 may consider the lack of a response as an indication that the SDT session is in progress. For example, instead of sending an indication at 910 whether the SDT session is in progress, while the SDT session is in progress, AS layer may wait until the SDT session has terminated (e.g., when AS layer 904 receives the request for the SDT status sent at 908, if the SDT session is in progress) to send an indication that the SDT session is not in progress (e.g., an indication that the SDT session has terminated).

[0117] At 916, AS layer 904 can use any suitable technique or combination of techniques to indicate that an SDT session is not in progress.

[0118] At 918, NAS layer 902 can use any suitable technique or combination of techniques to transition to an idle state (e.g., 5GMM-idle mode). In some aspects of this disclosure, the scheduled device 500 can remove the RRC context (e.g., UE inactive AS context), which may include removing the AS security context. In some aspects, NAS layer 902 can provide AS layer 904 with an indication to transition to an RRC idle state. In some aspects, suppressing NAS layer 902's transition to an idle state while an SDT session is in progress (e.g., until the SDT session is deactivated) can reduce the likelihood of interrupted packet delivery.

[0119] At 920, AS layer 904 can transition to RRC idle state based on NAS layer transitioning to idle state at 918.

[0120] In some respects, when the scheduled device transitions to an RRC idle state, AS layer 904 can locally release the RRC connection.

[0121] In 922, scheduling device 400 can use any suitable technology or combination of technologies to transition scheduled device 500 to an RRC idle state. For example, scheduling entity 400 can deregister scheduled device 500 after a threshold time has elapsed if there is no active session between scheduled device 500 and scheduling device 400.

[0122] Figure 10This is another call flow diagram illustrating an exemplary process for transmitting NAS messages and / or uplink user data packets using small data transfer, according to some aspects of this disclosure. As described below, some or all of the described features may be omitted in a particular implementation within the scope of this disclosure, and some described features are not required to be used in implementing all embodiments. In some examples, Figure 10 The process can be made by Figure 5 The dispatched devices 500 and / or Figure 4 The scheduling device 400 is executed. In some examples, Figure 10 The process can be performed by any suitable equipment or device for performing the functions or algorithms described below. In a more specific example, Figure 10 At least a portion of the process can be performed by the Non-Access Layer (NAS) layer 1002 and / or the Access Layer (AS) layer 1004. In such examples, operations associated with NAS layer 1002 can be performed by NAS management circuitry (e.g., implemented by processor 504) and / or by a NAS management module that executes based on NAS management instructions (e.g., storage using computer-readable medium 506). Operations associated with AS layer 1004 can be performed by AS management circuitry (e.g., implemented by processor 504) and / or by an AS management module that executes based on AS management instructions (e.g., storage using computer-readable medium 506).

[0123] At 1006, the AS layer 1004 associated with the scheduled entity (e.g., UE 106, scheduled entity 500) can provide the NAS layer 1002 with an indication that the RRC connection is being suspended and / or has been suspended. In some aspects, the AS layer can suspend the RRC connection in response to any appropriate instruction to suspend the RRC connection (such as an instruction from a scheduling device (e.g., base station 108, scheduling device 400)).

[0124] In some aspects of this disclosure, the indication provided at 1006 regarding an RRC connection being and / or being suspended can indicate that the scheduled device is transitioning (or has transitioned) from an RRC connected state to an RRC inactive state (e.g., in response to an RRC release from the scheduling device 400).

[0125] In some embodiments, NAS layer 1002 may transition from 5G Mobility Management (5GMM) connectivity mode to 5GMM connectivity mode with RRC inactivity indication based on an indication provided at 1006 (e.g., in response to the indication).

[0126] At 1008, scheduling device 400 can enable small data transfer (SDT) for scheduled device 500 during RRC inactive state. For example, in conjunction with the transition from RRC connected state to RRC inactive state, scheduled device 500 can request SDT to be enabled, and the scheduling entity can enable SDT (e.g., by assigning resources to scheduled device 400 for SDT while scheduled device 400 is in RRC inactive state).

[0127] At 1010, AS layer 1004 can provide an indication that SDT is enabled. In some aspects of this disclosure, AS layer 1004 can use any suitable technique or combination of techniques to provide an indication of SDT being enabled. For example, AS layer 1004 can set specific bits in a message conveying a pending RRC connection to indicate whether SDT is enabled (e.g., using 1 to indicate SDT is enabled and 0 to indicate SDT is not enabled, and vice versa).

[0128] At 1012, NAS layer 1002 may receive a trigger that causes the NAS layer to request the restoration of the RRC connection. In some aspects of this disclosure, any suitable trigger may cause NAS layer 1002 to request the restoration of the RRC connection. For example, NAS layer 1002 may generate a NAS message to be provided to the AMF. In a more specific example, NAS layer 1002 may generate a NAS message carrying location information from an upper layer and may attempt to send the location information to the AMF via the NAS message. As another example, NAS layer 1002 may receive (e.g., from an upper layer, such as an application layer or connection management layer in the operating system of the scheduled device) an indication that uplink (UL) user data packets are to be transmitted to a destination (e.g., via scheduling device 400). In some aspects, NAS layer 1002 may receive a trigger at any suitable time after the RRC connection is suspended and restored (or transitions to an RRC idle state) at 1012.

[0129] At 1014, NAS layer 1002 may send a request to AS layer 1004 to restore the RRC connection. For example, a scheduled device may request AS layer 1004 to transition to an RRC connected state in response to a trigger received at 1012. In some aspects of this disclosure, sending such an RRC restoration request from NAS layer 1002 to AS layer 1004 may facilitate the restoration of the RRC connection for the transmission of NAS messages and / or UL user data packets if AS layer 1004 determines that SDT will not be used to transmit NAS messages and / or UL user data packets. This can provide a mechanism for transmitting NAS messages regardless of whether the AS layer transmits NAS messages and / or UL user data packets via SDT, thereby facilitating SDT operation transparent to the NAS layer (e.g., the NAS layer can operate without knowing whether NAS messages or UL user data packets should be transmitted via SDT).

[0130] In some aspects of this disclosure, the scheduled device 400 may use any suitable technology or combination of technologies to provide an RRC recovery request to the AS layer 1004. For example, the NAS layer 1002 may enable the RRC recovery request to be provided to the AS layer 1004.

[0131] At 1016, the NAS layer can send NAS messages to be transmitted and / or enable the AS layer to transmit UL user data packets for PDUs. In some aspects of this disclosure, NAS layer 1002 can use any suitable technology or combination of technologies to provide NAS messages to be transmitted to AS layer 1004 and / or enable the transmission of UL user data packets. For example, NAS layer 1002 can pass NAS messages within the body of an RRC recovery request sent at 1012. As another example, NAS layer 1002 can transmit NAS messages as separate messages. As yet another example, NAS layer 1002 can implement the transmission of UL user data packets.

[0132] Alternatively, in some aspects of this disclosure, if AS layer 1004 does not indicate that SDT is enabled (and / or explicitly indicates that SDT is not enabled), NAS layer 1002 may wait to send a NAS message to AS layer 1004 until AS layer 1004 indicates to NAS layer 1002 that the scheduled device is in RRC connected state. For example, if AS layer 1004 indicates that SDT is not supported (e.g., explicitly or by omission), NAS layer 1002 may send an RRC recovery request at 1014, and may omit sending a NAS message at 1016 in conjunction with the RRC recovery request. In such an example, AS layer 1004 may transmit the RRC recovery request to the network. After the scheduled device moves to RRC connected state, AS layer 1004 may indicate to NAS layer 1002 that the scheduled device is in RRC connected state, and in response, NAS layer 1002 may pass a NAS message to AS layer 1004.

[0133] In 1018, AS layer 1004 can use any suitable technique or combination of techniques to determine whether to use a Small Data Transfer (SDT) session to transmit NAS messages and / or UL user data packets. For example, AS layer 1004 can determine whether to transmit NAS messages and / or UL user data packets based on the size of the NAS message and / or UL data packets. In such an example, if the NAS message and / or UL user data packets are below a threshold size, AS layer 1004 can determine to use an SDT session to transmit the NAS messages and / or UL user data packets. As another example, AS layer 1004 can determine whether to transmit NAS messages and / or UL user data packets based on an indication from NAS layer 1002 regarding whether to transmit and / or receive additional data. In some aspects, the threshold size of the SDT can be configured by the scheduling device (e.g., in conjunction with a transition of the scheduled device from RRC connectivity to RRC inactivity). Alternatively, the threshold size of the SDT can be predefined in the standard.

[0134] In some aspects of this disclosure, when the scheduled device is in an RRC inactive state, NAS layer 1002 can provide an indication associated with NAS messages (e.g., via a cause value). Such a cause value can cause AS layer 1004 to use SDT to transmit NAS messages (e.g., if SDT is enabled). For example, NAS layer 1002 can be configured to determine whether to initiate the transmission of messages not exceeding a threshold size via SDT. In such examples, NAS layer 1002 can prompt AS layer 1004 to utilize an SDT session to transmit NAS messages (e.g., instead of AS layer 1004 determining whether to transmit NAS messages via SDT).

[0135] At 1020, if AS layer 1004 determines that an SDT session should be used to transmit NAS messages and / or UL data packets, AS layer 1004 may transmit NAS messages and / or UL user data packets to scheduling entity 400 in the SDT session.

[0136] In some aspects of this disclosure, the scheduled device may use any suitable communication interface (such as a transceiver (e.g., transceiver 510)) to transmit NAS messages, at least a portion of UL user data packets, and / or any other suitable data. In some aspects, the scheduled device 500 may use any suitable signaling radio bearer (SRB) (such as SRB1 and / or SRB2) to transmit NAS messages. Additionally or alternatively, the scheduled device 500 may use one or more suitable data radio bearers (DRBs) to transmit at least a portion of UL user data packets and / or any other suitable data via an SDT session. In some aspects of this disclosure, transmitting NAS messages and / or at least a portion of UL user data packets when the scheduled device is in an RRC inactive state may facilitate earlier transmission of at least a portion of NAS messages and / or UL user data packets to the AMF (e.g., via the scheduling device 400 to the destination). This may reduce the latency of NAS messages and / or UL user data packets.

[0137] In some aspects of this disclosure, the scheduled device 500 may include any suitable information and / or content in the message. For example, the scheduled device may transmit shared control channel (CCH) messages and NAS messages.

[0138] In 1022, scheduling device 400 can receive at least a portion of NAS messages and / or UL user data packets transmitted using resources (e.g., one or more resource blocks) configured for SDT. For example, scheduling device 400 can configure specific resources to be used for an SDT session and can transmit an indication of which resources(s) should be used to transmit data in the SDT session.

[0139] In some aspects of this disclosure, the scheduling device 400 may further use any suitable technology or combination of technologies to process NAS messages and / or UL user data packets. For example, the scheduling device 400 may transmit a NAS message to the AMF as if the NAS message were received from the NAS layer during an RRC connected state (e.g., rather than during an SDT transmission from the AS layer during an RRC inactive state). As another example, the scheduling device 400 may cause UL data packets to be transmitted to the destination associated with the UL user data packets.

[0140] In some aspects of this disclosure, AS layer 1004 can transmit any suitable number of SDT messages during an SDT session without transitioning to RRC connectivity.

[0141] Figure 11 This is another call flow diagram illustrating an exemplary process for transitioning to a NAS idle state according to some aspects of this disclosure. As described below, some or all of the described features may be omitted in a particular implementation within the scope of this disclosure, and some described features are not required to be used in implementing all embodiments. In some examples, Figure 11 The process can be made by Figure 5 The dispatched devices 500 and / or Figure 4 The scheduling device 400 is executed. In some examples, Figure 11 The process can be performed by any suitable equipment or device for performing the functions or algorithms described below. In a more specific example, Figure 11 At least a portion of the process can be performed by the Non-Access Layer (NAS) layer 1102 and / or the Access Layer (AS) layer 1104. In such examples, operations associated with NAS layer 1102 can be performed by NAS management circuitry (e.g., implemented by processor 504) and / or by a NAS management module that executes based on NAS management instructions (e.g., using computer-readable medium 506 for storage). Operations associated with AS layer 1104 can be performed by AS management circuitry (e.g., implemented by processor 504) and / or by an AS management module that executes based on AS management instructions (e.g., using computer-readable medium 506 for storage).

[0142] At 1106, AS layer 1104, associated with the scheduled entity (e.g., UE 106, scheduled entity 500), can provide an indication that a Small Data Transfer (SDT) session is active. In some aspects of this disclosure, AS layer 1104 can use any suitable technique or combination of techniques to provide an indication that SDT is active. For example, AS layer 1104 can set specific bits in a message conveying the suspension of an RRC connection to indicate whether SDT is active (e.g., 1 to indicate SDT is enabled, and 0 to indicate SDT is not enabled, and vice versa). As another example, AS layer 1104 can provide an indication to NAS layer 1102 at the time of initiating an SDT session.

[0143] At 1108, NAS layer 1102 can use any suitable technique or combination of techniques to record that the SDT state is active. For example, the NAS layer can set an SDT active flag to indicate that the SDT session is active (e.g., by setting the flag from 0 to 1 to indicate that the SDT session is active, or vice versa).

[0144] At 1110, NAS layer 1102 can determine that NAS layer 1102 should (or must) transition to an idle state (e.g., 5GMM idle mode). In some aspects of this disclosure, NAS layer 1102 should transition to idle mode in response to any suitable conditions and / or any other suitable reason. For example, NAS layer 1102 can receive a trigger to send a registration request message to initiate a registration procedure for mobility and / or periodic registration. In a more specific example, NAS layer 1102 can receive a trigger to send a registration request message in which the NG-RAN-RCU bit of 5GS update type IE is set to "UE radio capability update required" (e.g., as described in 3GPP TS 24.501 version 15).

[0145] At 1112, NAS layer 1102 can determine that the SDT session is active. In some aspects of this disclosure, NAS layer 1102 can use any suitable technique or combination of techniques to determine that the SDT is active. For example, NAS layer 1102 can check the status of the recorded SDT session (e.g., the status of the SDT session flag). As another example, NAS layer 1102 can send a query to AS layer 1104 regarding the SDT session status (e.g., supplementing or replacing AS layer 1104 sending an indication at 1106).

[0146] At 1114, NAS layer 1102 can wait for a predetermined amount of time for an ongoing SDT session to end (e.g., based on an indication at 1112 that the SDT session is active).

[0147] At 1116, AS layer 1104 can provide an indication that a Small Data Transfer (SDT) session has been deactivated. In some aspects of this disclosure, AS layer 1104 can use any suitable technique or combination of techniques to provide the indication that an SDT has been deactivated. For example, AS layer 1104 can provide an indication to NAS layer 1102 upon deactivation of an SDT session.

[0148] At 1118, NAS layer 1102 can use any suitable technique or combination of techniques to record that the SDT state is disabled (or otherwise inactive). For example, NAS layer 1102 can set an SDT active flag to indicate that the SDT session is active (e.g., by setting the flag from 0 to 1 to indicate that the SDT session is disabled, or vice versa).

[0149] At 1120, NAS layer 1102 can use any suitable technique or combination of techniques to transition to an idle state (e.g., 5GMM-idle mode). In some aspects of this disclosure, the scheduled device 500 can remove the RRC context (e.g., UE inactive AS context), which may include removing the AS security context. In some aspects, NAS layer 1102 can provide AS layer 1104 with an indication to transition to an RRC idle state. In some aspects, suppressing NAS layer 1102's transition to an idle state while an SDT session is in progress (e.g., until the SDT session is deactivated) can reduce the likelihood of interrupted packet delivery.

[0150] At 1122, AS layer 1104 can transition to RRC idle state based on NAS layer 1102 transitioning to idle state at 1120. In some aspects, when the scheduled device transitions to RRC idle state, AS layer 1104 can locally release the RRC connection.

[0151] At 1124, scheduling device 400 may use any suitable technique or combination of techniques to transition scheduled device 500 to an RRC idle state. For example, scheduling entity 400 may deregister scheduled device 500 after a threshold time has elapsed if there is no active session between scheduled device 500 and scheduling device 400.

[0152] Figure 12 This is a call flow diagram illustrating an exemplary process for transmitting NAS messages and / or uplink user data packets using small data transfer, according to some aspects of this disclosure. As described below, some or all of the described features may be omitted in a particular implementation within the scope of this disclosure, and some described features are not required to be used in implementing all embodiments. In some examples, Figure 12 The process can be made by Figure 5 The dispatched devices 500 and / or Figure 4 The scheduling device 400 is executed. In some examples, Figure 12 The process can be performed by any suitable equipment or device for performing the functions or algorithms described below. In a more specific example, Figure 12 At least a portion of the process can be performed by the Non-Access Layer (NAS) layer 1202 and / or the Access Layer (AS) layer 1204. In such examples, operations associated with NAS layer 1202 can be performed by NAS management circuitry (e.g., implemented by processor 504) and / or by a NAS management module that executes based on NAS management instructions (e.g., using computer-readable media 506 for storage). Operations associated with AS layer 1204 can be performed by AS management circuitry (e.g., implemented by processor 504) and / or by an AS management module that executes based on AS management instructions (e.g., using computer-readable media 506 for storage).

[0153] At 1206, the AS layer 1304 associated with the scheduled entity (e.g., UE 106, scheduled entity 500) can provide the NAS layer 1202 with an indication that the RRC connection is being suspended and / or has been suspended. In some aspects, the AS layer 1204 can suspend the RRC connection in response to any appropriate instruction to suspend the RRC connection (such as an instruction from a scheduling device (e.g., base station 108, scheduling device 400)).

[0154] In some aspects of this disclosure, the indication provided at 1206 regarding an RRC connection being and / or being suspended can indicate that the scheduled device is transitioning (or has transitioned) from an RRC connected state to an RRC inactive state (e.g., in response to an RRC release from the scheduling device 400).

[0155] In some embodiments, NAS layer 1202 may transition from 5G Mobility Management (5GMM) connectivity mode to 5GMM connectivity mode with RRC inactivity indication based on an indication provided at 1206 (e.g., in response to the indication).

[0156] At 1208, NAS layer 1202 may receive a trigger that causes NAS layer 1202 to request the restoration of the RRC connection. In some aspects of this disclosure, any suitable trigger may cause NAS layer 1202 to request the restoration of the RRC connection. For example, NAS layer 1202 may generate a NAS message to be provided to the AMF. In a more specific example, NAS layer 1202 may generate a NAS message carrying location information from an upper layer and may attempt to send the location information to the AMF via the NAS message. As another example, NAS layer 1202 may receive (e.g., from an upper layer, such as an application layer or connection management layer in the operating system of the scheduled device) an indication that uplink (UL) user data packets are to be transmitted to a destination (e.g., via scheduling device 400). In some aspects, NAS layer 1202 may receive a trigger at 1208 at any suitable time after the RRC connection is suspended and restored (or transitions to an RRC idle state).

[0157] At 1210, NAS layer 1202 may send a request to AS layer 1204 to restore RRC connectivity. For example, a scheduled device may request AS layer 1204 to transition to RRC connected state in response to a trigger received at 1208. In some aspects of this disclosure, sending such an RRC restoration request from NAS layer 1202 to AS layer 1204 may facilitate the restoration of RRC connectivity for the transmission of NAS messages and / or UL user data packets if AS layer 1204 determines that SDT will not be used to transmit NAS messages and / or UL user data packets. This can provide a mechanism for transmitting NAS messages regardless of whether AS layer transmits NAS messages and / or UL user data packets via SDT, thereby facilitating SDT operation transparent to NAS layer (e.g., NAS layer can operate without knowing whether NAS messages or UL user data packets should be transmitted via SDT).

[0158] In some aspects of this disclosure, the scheduled device 400 may use any suitable technology or combination of technologies to provide an RRC recovery request to the AS layer 1204. For example, the NAS layer 1202 may enable the RRC recovery request to be provided to the AS layer 1204.

[0159] At 1212, the NAS layer can send NAS messages to be transmitted and / or enable the AS layer to transmit UL user data packets for PDUs. In some aspects of this disclosure, NAS layer 1202 can use any suitable technology or combination of technologies to provide NAS messages to be transmitted to AS layer 1204 and / or enable the transmission of UL user data packets. For example, NAS layer 1202 can pass NAS messages within the body of an RRC recovery request sent at 1210. As another example, NAS layer 1202 can transmit NAS messages as separate messages. As yet another example, NAS layer 1202 can implement the transmission of UL user data packets.

[0160] At 1214, AS layer 1204 can use any suitable technique or combination of techniques to determine whether to use a Small Data Transfer (SDT) session to perform the transmission of NAS messages and / or UL user data packets. For example, AS layer 1204 can determine whether to transmit NAS messages and / or UL user data packets based on the size of the NAS messages and / or UL user data packets. In such an example, if the NAS messages and / or UL user data packets exceed a threshold size, AS layer 1204 can determine not to use an SDT session to transmit the NAS messages and / or UL user data packets (e.g., because the NAS messages and / or UL user data packets cannot be transmitted using the resources configured for SDT). As another example, AS layer 1204 can determine whether to transmit NAS messages and / or UL user data packets based on an indication from NAS layer 1202 regarding whether to transmit and / or receive additional data (e.g., if sufficient additional data is to be transmitted and / or received, AS layer 1202 can determine that the scheduled device should transition to RRC connectivity). In some respects, the threshold size of the SDT can be configured by the scheduling device (e.g., in conjunction with the transition of a scheduled device from RRC connectivity to RRC inactivity). Alternatively, the threshold size of the SDT can be predefined in a standard.

[0161] At 1216, if AS layer 1204 determines that SDT sessions are not used to transmit NAS messages and / or UL data packets, AS layer 1204 may send an RRC connection restoration request to scheduling entity 400 to attempt to transition to RRC connected state.

[0162] In some aspects of this disclosure, the scheduled device may use any suitable communication interface (such as a transceiver (e.g., transceiver 510)) to transmit the RRC recovery request. In some aspects, the scheduled device 500 may use any suitable signaling radio bearer (SRB) (such as SRB1 and / or SRB2) to transmit the RRC recovery request. In some aspects of this disclosure, the scheduled device 500 may include any suitable information and / or content in the message. For example, the scheduled device may transmit one or more messages associated with a RACH procedure (e.g., a two-step RACH procedure or a four-step RACH procedure).

[0163] At 1218, the scheduling device 400 can transmit a message instructing the scheduled device to switch to RRC connectivity. For example, the scheduling device 400 can transmit an RRC recovery message to the scheduled device.

[0164] At 1220, AS layer 1204 can indicate to NAS layer 1202 that AS layer 1204 has transitioned to RRC connected state.

[0165] At 1222, the NAS layer can transmit a NAS message to the AMF in response to an indication that the AS layer 1204 has transitioned to the RRC connected state. For example, the NAS layer 1202 can pass the NAS message to the AS layer for transmission to the AMF via the scheduling entity 400. In some aspects of this disclosure, 1222 can be omitted (e.g., when the NAS message is not triggered at 1208).

[0166] In some aspects of this disclosure, the scheduled device may use any suitable communication interface (such as a transceiver (e.g., transceiver 510)) to transmit NAS messages. In some aspects, the scheduled device 500 may use any suitable signaling radio bearer (SRB) (such as SRB1 and / or SRB2) to transmit NAS messages.

[0167] At 1224, AS layer 1204 can transmit UL user data packets to the scheduling device in response to AS layer 1204 transitioning to RRC connected state. In some aspects of this disclosure, the scheduled device can use any suitable communication interface (such as a transceiver (e.g., transceiver 510)) to transmit UL user data packets. In some aspects, the scheduled device 500 can use one or more suitable data radio bearers (DRBs) to transmit at least a portion of the UL user data packets and / or any other suitable data.

[0168] In some aspects of this disclosure, the scheduling device 400 may further use any suitable technology or combination of technologies to process NAS messages and / or UL user data packets. For example, the scheduling device 400 may transmit NAS messages to the AMF. As another example, the scheduling device 400 may cause UL data packets to be transmitted to the destination associated with the UL user data packets.

[0169] Further examples with various characteristics

[0170] Examples of implementations are described in the following numbered clauses:

[0171] 1. A wireless communication method comprising: when a user equipment (UE) is in a radio resource control (RRC) inactive state, providing a NAS message to an access layer (AS) associated with the UE from a non-access layer (NAS) layer associated with the UE to a mobility management entity via a base station; providing a request to restore RRC connection from the NAS layer; and transmitting the NAS message to the base station when the UE is in the RRC inactive state.

[0172] 2. The method of Clause 1 further includes: receiving at the NAS layer an indication that the AS layer supports data transmission when the UE is in the RRC inactive state.

[0173] 3. The method of Clause 2, wherein the indication that the AS layer supports data transmission when the UE is in the RRC inactive state is provided in conjunction with the indication that the RRC connectivity state is suspended.

[0174] 4. The method of Clause 2 further includes: providing the AS layer with a request indicating whether the AS layer supports data transmission when the UE is in the RRC inactive state; and in response to the request, receiving at the NAS layer an indication that the AS layer supports data transmission when the UE is in the RRC inactive state.

[0175] 5. The method of Clause 4 further includes: determining that the procedure that caused the transmission of the NAS message has been triggered.

[0176] 6. The method of Clause 5 further includes: providing a request indicating whether the AS layer supports data transmission when the UE is in the RRC inactive state before determining that the procedure that caused the transmission of the NAS message has been triggered.

[0177] 7. The method of Clause 5 further includes: providing a request indicating whether the AS layer supports data transmission when the UE is in the RRC inactive state in response to determining that the procedure that caused the transmission of the NAS message has been triggered.

[0178] 8. The method of any of Clauses 2 to 7, wherein providing the NAS message to be transmitted to the base station further comprises: providing the AS layer with the NAS message to be transmitted to the base station based on the indication that the AS layer supports data transmission when the UE is in the RRC inactive state.

[0179] 9. The method of any one of Clauses 1 to 8 further includes: determining that the NAS layer is to transition to an idle state; and providing the AS layer with a request indicating whether the AS layer is transmitting data when the UE is in the RRC inactive state.

[0180] 10. The method of Clause 9, wherein the idle state is a 5G mobile mobility (5GMM) idle state.

[0181] 11. The method of Clause 9 further includes: receiving from the AS layer an indication that the AS layer is transmitting data when the UE is in the RRC inactive state; and in response to the indication that the AS layer is transmitting data when the UE is in the RRC inactive state, waiting until the AS layer indicates that it will no longer transmit data when the UE is in the RRC inactive state before transitioning to the idle state.

[0182] 12. The method of Clause 9 further includes: receiving from the AS layer an indication that the AS layer is not transmitting data when the UE is in the RRC inactive state; and transitioning to the idle state in response to the indication that the AS layer is not transmitting data when the UE is in the RRC inactive state.

[0183] 13. The method of any one of clauses 1 to 12 further includes: receiving a downlink NAS message when the UE is in the RRC inactive state; and performing a NAS procedure based on the downlink NAS message when the UE remains in the RRC inactive state.

[0184] 14. The method of Clause 1 further includes: at the NAS layer, receiving an indication that data transmission is enabled when the UE is in the RRC inactive state.

[0185] 15. The method of Clause 14, wherein the indication that data transmission is enabled when the UE is in the RRC inactive state is provided in conjunction with an indication that the RRC connectivity state is suspended.

[0186] 16. The method of Clause 14 further includes: determining that the procedure that caused the transmission of the NAS message has been triggered.

[0187] 17. The method of Clause 16 further includes: receiving an indication that data transmission is enabled when the UE is in the RRC inactive state before determining that the procedure that caused the transmission of the NAS message has been triggered.

[0188] 18. The method of any of Clauses 14 to 17, wherein providing the NAS message to be transmitted to the base station further comprises: providing the AS layer with the NAS message to be transmitted to the base station based on an indication that data transmission is enabled when the UE is in the RRC inactive state.

[0189] 19. The method of any one of Clauses 14 to 18 further includes: receiving at the NAS layer an indication that data transmission is active when the UE is in the RRC inactive state.

[0190] 20. The method of Clause 19 further includes: receiving, at the NAS layer, an indication that data transmission is inactive when the UE is in the RRC inactive state after receiving an indication that data transmission is active when the UE is in the RRC inactive state.

[0191] 21. The method of any one of Clauses 19 to 20, further comprising: determining that the NAS layer is to transition to an idle state; and determining whether data transmission of the UE is inactive when it is in the RRC inactive state; and in response to determining that data transmission of the UE is active when it is in the RRC inactive state, waiting until the AS layer indicates that data transmission of the UE is inactive when it is in the RRC inactive state before transitioning to the idle state.

[0192] 22. The method of any one of Clauses 19 to 20 further includes: determining that the NAS layer is to transition to an idle state; and determining whether data transmission of the UE is inactive when it is in the RRC inactive state; and transitioning to the idle state in response to determining that data transmission of the UE is inactive when it is in the RRC inactive state.

[0193] 23. The method of any of Clauses 21 to 22, wherein the idle state is a 5G mobile mobility (5GMM) idle state.

[0194] 24. The method of any one of clauses 14 to 23 further includes: receiving a downlink NAS message when the UE is in the RRC inactive state; and performing a NAS procedure based on the downlink NAS message when the UE remains in the RRC inactive state.

[0195] 25. The method of any one of clauses 1 to 24, further comprising: determining at the NAS layer that the UE is in the RRC inactive state to transmit the NAS message; providing from the NAS layer to the AS layer a cause value associated with the request to transmit the NAS message when the UE is in the RRC inactive state; and based on the cause value, transmitting the NAS message to the base station when the UE is in the RRC inactive state.

[0196] 26. The method of any one of clauses 1 to 24, wherein the NAS message includes a location protocol message, the method further comprising: providing a cause value associated with the NAS message from the NAS layer to the AS layer; and transmitting the NAS message to the base station based on the cause value when the UE is in the RRC inactive state.

[0197] 27. The method of any of 1 to 26 further includes: providing an indication from the NAS layer to the AS layer regarding the expectation of a single uplink in conjunction with the NAS message.

[0198] 28. The method of any of Clauses 1 to 27 further includes: providing an indication from the NAS layer to the AS layer regarding the expected subsequent downlink messages.

[0199] 29. The method of any of Clauses 1 to 28, wherein transmitting the NAS message to the base station when the UE is in the RRC inactive state comprises: transmitting the NAS message in conjunction with a third message of the four-step random access channel (RACH) procedure.

[0200] 30. The method of any of Clauses 1 to 28, wherein transmitting the NAS message to the base station when the UE is in the RRC inactive state comprises: transmitting the NAS message in conjunction with the first message of the two-step random access channel (RACH) procedure.

[0201] 31. The method of any of Clauses 1 to 28, wherein transmitting the NAS message to the base station when the UE is in the RRC inactive state comprises: transmitting the NAS message using an uplink time slot granted by the base station via RRC signaling. 32. A wireless communication method comprising: enabling transmission of uplink (UL) user data packets associated with a Protocol Data Unit (PDU) session to a base station by a Non-Access Layer (NAS) layer associated with the UE when the user equipment (UE) is in a Radio Resource Control (RRC) inactive state; providing a request from the NAS layer to resume the Radio Resource Control (RRC) connection; and transmitting the UL user data packets to the base station when the UE is in the RRC inactive state.

[0202] 33. The method of Clause 32 further includes: receiving at the NAS layer an indication that the AS layer supports data transmission when the UE is in the RRC inactive state.

[0203] 34. The method of Clause 33, wherein the indication regarding the AS layer supporting data transmission when the UE is in the RRC inactive state is provided in conjunction with an indication regarding the RRC connectivity state being suspended.

[0204] 35. The method of Clause 33 further includes: providing the AS layer with a request indicating whether the AS layer supports data transmission when the UE is in the RRC inactive state; and receiving at the NAS layer an indication that the AS layer supports data transmission when the UE is in the RRC inactive state.

[0205] 36. The method of Clause 35 further includes: determining to use the suspended user plane resources to send UL data packets for the PDU.

[0206] 37. The method of Clause 36 further includes: providing a request indicating whether the AS layer supports data transmission when the UE is in the RRC inactive state before determining whether to use the suspended user plane resources to send the UL data packet for the PDU.

[0207] 38. The method of Clause 36 further includes: in response to determining that the UL data packet for the PDU is to be transmitted using the suspended user plane resources, providing a request indicating whether the AS layer supports data transmission when the UE is in the RRC inactive state.

[0208] 39. The method of any of Clauses 34 to 38, wherein providing the indication that the UL user data packet for the PDU session is to be transmitted to the base station further comprises: providing the AS layer with the indication that the AS layer supports data transmission when the UE is in the RRC inactive state, based on the indication that the AS layer supports data transmission when the UE is in the RRC inactive state.

[0209] 40. The method of any one of clauses 32 to 39 further includes: determining that the NAS layer is to transition to an idle state; and providing the AS layer with a request indicating whether the AS layer is transmitting data when the UE is in the RRC inactive state.

[0210] 41. The method of Clause 40, wherein the idle state is a 5G mobile mobility (5GMM) idle state.

[0211] 42. The method of Clause 40 further includes: receiving from the AS layer an indication that the AS layer is transmitting data when the UE is in the RRC inactive state; and in response to the indication that the AS layer is transmitting data when the UE is in the RRC inactive state, waiting until the AS layer indicates that it will no longer transmit data when the UE is in the RRC inactive state before transitioning to the idle state.

[0212] 43. The method of Clause 40 further includes: receiving from the AS layer an indication that the AS layer is not transmitting data when the UE is in the RRC inactive state; and transitioning to the idle state in response to the indication that the AS layer is not transmitting data when the UE is in the RRC inactive state.

[0213] 44. The method of Clause 32 further includes: receiving at the NAS layer an indication that data transmission of the UE in the RRC inactive state is enabled.

[0214] 45. The method of Clause 44, wherein the indication that data transmission is enabled when the UE is in the RRC inactive state is provided in conjunction with an indication that the RRC connectivity state is suspended.

[0215] 46. ​​The method of Clause 44 further includes: determining the UL user data packet to be transmitted for the PDU session.

[0216] 47. The method of Clause 46 further includes: receiving an indication that data transmission is enabled when the UE is in the RRC inactive state before determining that the UL user data packet for the PDU session is to be transmitted.

[0217] 48. The method of any of clauses 44 to 47, wherein enabling the transmission of the UL user data packets for the PDU session to the base station further comprises: enabling the transmission of the UL user data packets for the PDU session to the base station to the AS layer based on an indication that data transmission is enabled when the UE is in the RRC inactive state.

[0218] 49. The method of any one of clauses 44 to 48 further includes: receiving at the NAS layer an indication that data transmission is active when the UE is in the RRC inactive state.

[0219] 50. The method of Clause 49 further includes: after receiving an indication that data transmission is active when the UE is in the RRC inactive state, receiving at the NAS layer an indication that data transmission is inactive when the UE is in the RRC inactive state.

[0220] 51. The method of any one of Clauses 49 to 50 further comprises: determining that the NAS layer is to transition to an idle state; determining whether data transmission of the UE is inactive when it is in the RRC inactive state; and, in response to determining that data transmission of the UE is active when it is in the RRC inactive state, waiting until the AS layer indicates that data transmission of the UE is inactive when it is in the RRC inactive state before transitioning to the idle state.

[0221] 52. The method of any one of Clauses 49 to 50 further comprises: determining that the NAS layer is to transition to an idle state; and determining whether data transmission of the UE is inactive when it is in the RRC inactive state; and transitioning to the idle state in response to determining that data transmission of the UE is inactive when it is in the RRC inactive state.

[0222] 53. The method of any of Clauses 51 to 52, wherein the idle state is a 5G mobile mobility (5GMM) idle state.

[0223] 54. The method of any of clauses 32 to 53 further includes: providing an indication from the NAS layer to the AS layer regarding the expected subsequent downlink message.

[0224] 55. The method of any of clauses 32 to 53, wherein transmitting the UL data packet to the base station when the UE is in the RRC inactive state comprises: transmitting the UL data packet in conjunction with a third message of the four-step random access channel (RACH) procedure.

[0225] 56. The method of any of clauses 32 to 53, wherein transmitting the UL data packet to the base station when the UE is in the RRC inactive state comprises: transmitting the UL data packet in conjunction with the first message of the two-step random access channel (RACH) procedure.

[0226] 57. The method of any one of clauses 32 to 53, wherein transmitting the UL data packet to the base station when the UE is in the RRC inactive state comprises: transmitting the UL data packet using an uplink time slot granted by the base station via RRC signaling. 58. A wireless communication method comprising: when a user equipment (UE) is in a radio resource control (RRC) inactive state, providing a NAS message to be transmitted to a base station from a non-access layer (NAS) layer associated with the UE to an access layer (AS) layer associated with the UE; providing a request to restore RRC connection from the NAS layer; receiving an indication from the AS layer to the NAS layer that the UE has transitioned to an RRC connected state; and, upon receiving the indication that the UE has transitioned to an RRC connected state, transmitting the NAS message to a mobility management entity via the NAS layer.

[0227] 58. A wireless communication method comprising: when a user equipment (UE) is in a radio resource control (RRC) inactive state, providing a NAS message to be transmitted to a base station from a non-access layer (NAS) layer associated with the UE to an access layer (AS) layer associated with the UE; providing a request to restore RRC connection from the NAS layer; receiving an indication from the AS layer to the NAS layer that the UE has transitioned to an RRC connected state; and, upon receiving the indication that the UE has transitioned to an RRC connected state, transmitting the NAS message to a mobility management entity via the NAS layer.

[0228] 59. An apparatus for wireless communication, comprising: a processor; and a memory communicatively coupled to the at least one processor, wherein the processor and the memory are configured to: perform the method of any one of clauses 1 to 58.

[0229] 60. A non-transient computer-readable medium storing computer-executable code, including code for causing a computer to cause a processor to perform the following operation: a method for performing any one of clauses 1 to 58.

[0230] 61. An apparatus for wireless communication, comprising: at least one means for performing a method as described in any one of clauses 1 to 58.

[0231] This disclosure presents several aspects of wireless communication networks through exemplary implementations. As will be readily apparent to those skilled in the art, the various aspects described herein can be extended to other telecommunications systems, network architectures, and communication standards.

[0232] As examples, various aspects can be implemented within other systems defined by 3GPP, such as Long Term Evolution (LTE), Evolved Packet System (EPS), Universal Mobile Telecommunications System (UMTS), and / or Global System for Mobile Communications (GSM). These aspects can also be extended to systems defined by 3GPP2 (3GPP2), such as CDMA2000 and / or Evolved Data Optimized (EV-DO). Other examples can be implemented within systems employing IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra Wideband (UWB), Bluetooth, and / or other suitable systems. The actual telecommunications standards, network architecture, and / or communication standards employed will depend on the specific application and the overall design constraints imposed on the system.

[0233] This disclosure uses the term "exemplary" to mean "serving as an example, instance, or illustration." Any implementation or aspect described herein as "exemplary" need not be construed as superior to or better than other aspects of this disclosure. Similarly, the term "aspect" does not require that all aspects of this disclosure include the features, advantages, or modes of operation discussed. This disclosure uses the term "coupling" to refer to direct or indirect coupling between two objects. For example, if object A is physically in contact with object B, and object B is in contact with object C, then objects A and C can still be considered coupled to each other—even if they are not in direct physical contact with each other. For example, a first object can be coupled to a second object, even if the first object never is in direct physical contact with the second object. This disclosure uses the terms "circuit" and "circuit system" broadly to include both hardware implementations of electronic devices and conductors and software implementations of information and instructions that, when connected and configured, enable the performance of the functions described in this disclosure, without limitation on the type of electronic circuit, and that, when executed by a processor, enable the performance of the functions described in this disclosure.

[0234] Figure 1-12 One or more of the components, steps, features, and / or functions described herein may be rearranged and / or combined into a single component, step, feature, or function, or implemented in several components, steps, or functions. Additional elements, components, steps, and / or functions may also be added without departing from the novel features disclosed herein. Figure 1-12The apparatus, devices, and / or components described herein can be configured to perform one or more methods, features, or steps as described herein. The novel algorithms described herein can also be efficiently implemented in software and / or embedded in hardware.

[0235] It will be understood that the specific order or hierarchy of the steps in the disclosed methods is an explanation of an exemplary process. Based on design preferences, it will be understood that the specific order or hierarchy of the steps in these methods may be rearranged. The appended method claims present the elements of the various steps in a sample order and are not intended to be limited to the specific order or hierarchy presented, unless specifically stated herein.

[0236] The applicant provides this description to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. The applicant is not intended to be limited to the aspects shown herein, but should be granted the full scope consistent with the language of the claims, wherein references to the singular form of an element are not intended to mean “one and only one” unless specifically stated otherwise, but are intended to mean “one or more.” Unless otherwise specifically stated, this disclosure uses the term “some” to refer to one or more. The phrase “at least one” referring to a list of items refers to any combination of these items, including a single member. As an example, “at least one of a, b, or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, b, and c. All structural and functional equivalents of the aspects described throughout this disclosure that are currently or hereafter known to a person skilled in the art are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, nothing disclosed herein is intended to be donated to the public, whether or not such disclosure is expressly stated in the claims.

Claims

1. A method for wireless communication, comprising: When the user equipment (UE) is in an inactive state of Radio Resource Control (RRC), the NAS message to be transmitted to the mobility management entity via the base station is provided from the Non-Access Stratum (NAS) layer associated with the UE to the Access Stratum (AS) layer associated with the UE. A request to restore the RRC connection is provided from the NAS layer to the AS layer; At the NAS layer, an indication is received from the AS layer regarding the AS layer's support for data transmission when the UE is in the RRC inactive state, wherein the NAS message to be transmitted to the base station is provided based on the indication; as well as Before the RRC connection is restored, the NAS message is transmitted to the base station when the UE is in the RRC inactive state.

2. The method of claim 1, further comprising: A request is provided to the AS layer indicating whether the AS layer supports data transmission when the UE is in the RRC inactive state; as well as In response to the request, an indication is received at the NAS layer regarding the AS layer's support for data transmission when the UE is in the RRC inactive state.

3. The method of claim 2, further comprising: It has been determined that the procedure that caused the NAS message to be sent has been triggered.

4. The method of claim 1, further comprising: The UE receives a downlink NAS message when it is in the RRC inactive state. as well as When the UE maintains the RRC inactive state, the NAS procedure is executed based on the downlink NAS message.

5. The method of claim 1, further comprising: At the NAS layer, an indication is received that data transmission is enabled when the UE is in the RRC inactive state.

6. The method of claim 1, wherein transmitting the NAS message to the base station when the UE is in the RRC inactive state comprises: The NAS message is transmitted in conjunction with the third message of the four-step random access channel (RACH) procedure.

7. The method of claim 1, wherein transmitting the NAS message to the base station when the UE is in the RRC inactive state comprises: The NAS message is transmitted by combining the first message of the two-step random access channel (RACH) procedure.

8. A method for wireless communication, comprising: When the user equipment (UE) is in an inactive state of Radio Resource Control (RRC), the transmission of uplink UL user data packets associated with the Protocol Data Unit (PDU) session to the base station is enabled by the Non-Access Stratum (NAS) layer associated with the UE. The NAS layer provides a request to the access layer AS layer to restore the Radio Resource Control (RRC) connection; At the NAS layer, an indication is received from the AS layer regarding the AS layer's support for data transmission when the UE is in the RRC inactive state, wherein the UL user data packets to be transmitted to the base station are provided based on the indication; as well as Before the RRC connection is restored, when the UE is in the RRC inactive state, the UL user data packet is transmitted to the base station.

9. The method of claim 8, further comprising: A request is provided to the AS layer indicating whether the AS layer supports data transmission when the UE is in the RRC inactive state; as well as In response to the request, an indication is received at the NAS layer regarding the AS layer's support for data transmission when the UE is in the RRC inactive state.

10. The method of claim 9, further comprising: It is determined that the suspended user plane resources will be used to send the UL user data packets for the PDU.

11. The method of claim 8, further comprising: At the NAS layer, an indication is received that data transmission is enabled when the UE is in the RRC inactive state.

12. The method of claim 8, further comprising: The NAS layer provides an indication to the AS layer regarding the expected subsequent downlink messages.

13. The method of claim 8, wherein transmitting the UL user data packet to the base station when the UE is in the RRC inactive state comprises: The UL data packets are transmitted in conjunction with the third message of the four-step random access channel (RACH) procedure.

14. A wireless communication device, comprising: transceiver; Memory; as well as One or more processors, communicatively coupled to the transceiver and the memory, are configured to: When the user equipment (UE) is in an inactive state of Radio Resource Control (RRC), the NAS message to be transmitted to the mobility management entity via the base station is provided from the Non-Access Stratum (NAS) layer associated with the UE to the Access Stratum (AS) layer associated with the UE. A request to restore the RRC connection is provided from the NAS layer to the AS layer; At the NAS layer, an indication is received from the AS layer regarding the AS layer's support for data transmission when the UE is in the RRC inactive state, wherein the NAS message to be transmitted to the base station is provided based on the indication; as well as Before the RRC connection is restored, the NAS message is transmitted to the base station when the UE is in the RRC inactive state.

15. The wireless communication device of claim 14, wherein the one or more processors are configured to: Provide the AS layer with a request indicating whether the AS layer supports data transmission when the UE is in the RRC inactive state; and In response to the request, an indication is received at the NAS layer regarding the AS layer's support for data transmission when the UE is in the RRC inactive state.

16. The wireless communication device of claim 15, wherein the one or more processors are further configured to: It has been determined that the procedure that caused the NAS message to be sent has been triggered.

17. The wireless communication device of claim 14, wherein the one or more processors are further configured to: When the UE is in the RRC inactive state, it receives a downlink NAS message; and When the UE maintains the RRC inactive state, the NAS procedure is executed based on the downlink NAS message.

18. The wireless communication device of claim 14, wherein the one or more processors are further configured to: At the NAS layer, an indication is received that data transmission is enabled when the UE is in the RRC inactive state.

19. The wireless communication device of claim 14, wherein, in order to transmit the NAS message to the base station when the UE is in the RRC inactive state, the one or more processors are further configured to: The NAS message is transmitted in conjunction with the third message of the four-step random access channel (RACH) procedure.

20. The wireless communication device of claim 14, wherein, in order to transmit the NAS message to the base station when the UE is in the RRC inactive state, the one or more processors are further configured to: The NAS message is transmitted by combining the first message of the two-step random access channel (RACH) procedure.

21. A wireless communication device, comprising: transceiver; Memory; as well as One or more processors, communicatively coupled to the transceiver and the memory, are configured to: When the user equipment (UE) is in an inactive state of Radio Resource Control (RRC), the transmission of uplink UL user data packets associated with the Protocol Data Unit (PDU) session to the base station is enabled by the Non-Access Stratum (NAS) layer associated with the UE. The NAS layer provides a request to the access layer AS layer to restore the Radio Resource Control (RRC) connection; At the NAS layer, an indication is received from the AS layer regarding the AS layer's support for data transmission when the UE is in the RRC inactive state, wherein the UL user data packets to be transmitted to the base station are provided based on the indication; as well as Before the RRC connection is restored, when the UE is in the RRC inactive state, the UL user data packet is transmitted to the base station.

22. The wireless communication device of claim 21, wherein the one or more processors are further configured to: Provide the AS layer with a request indicating whether the AS layer supports data transmission when the UE is in the RRC inactive state; and In response to the request, an indication is received at the NAS layer regarding the AS layer's support for data transmission when the UE is in the RRC inactive state.

23. The wireless communication device of claim 22, wherein the one or more processors are further configured to: It is determined that the suspended user plane resources will be used to send the UL user data packets for the PDU.

24. The wireless communication device of claim 21, wherein the one or more processors are further configured to: At the NAS layer, an indication is received that data transmission is enabled when the UE is in the RRC inactive state.

25. The wireless communication device of claim 21, wherein the one or more processors are further configured to: The NAS layer provides an indication to the AS layer regarding the expected subsequent downlink messages.

26. The wireless communication device of claim 21, wherein, in order to transmit the UL user data packet to the base station when the UE is in the RRC inactive state, the one or more processors are further configured to: The UL user data packets are transmitted in conjunction with the third message of the four-step random access channel (RACH) procedure.

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