Uplink small data transmission in the inactive state

Abstract

As an improvement to New Radio (NR) technology, methods and apparatus are provided for optimizing delivery of data to and / or from user equipment in inactive network conditions. [Solution] In delivering data to and / or from a UE in a connected but inactive state, the method includes, while the UE is in a state in which dedicated resources are not allocated to the UE, generating a message having encrypted uplink data using a first UE identification information encrypted using a first key and a second key derived based on information obtained from a first base station in a first cell before transitioning to that state, and transmitting the message to a second base station in a second cell.

Description

Technical Field

[0001] Cross - reference to Related Applications and Claim of Priority This application claims the benefit and priority of International Patent Cooperation Treaty Application No. PCT / CN2017 / 085701, filed on May 24, 2017, which has been assigned to the assignee of this application and is hereby expressly incorporated by reference herein in its entirety for all applicable purposes as if fully set forth herein.

[0002] The present disclosure generally relates to communication systems, and more particularly, to methods and apparatuses for optimizing the delivery of data from a user equipment (UE) in a non - active network state.

Background Art

[0003] Wireless communication systems have been widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcast. A general wireless communication system may employ a multiple access technology that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple access technologies include Long Term Evolution (LTE) systems, Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single - Carrier Frequency Division Multiple Access (SC - FDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD - SCDMA) systems.

[0004] In some examples, a wireless multi-connectivity communication system may include several base stations, each simultaneously supporting communication for a plurality of communication devices, also known as user equipment (UE). In an LTE or LTE-A network, a set of one or more base stations may define an evolved Node B (eNB). In other examples (e.g., in a next generation or 5G network), a wireless multi-connectivity communication system may include several distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmit receive points (TRPs), etc.) communicating with several centralized units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), and a set of one or more DUs communicating with the CU may define an access node (e.g., a new radio base station (NR BS), a new radio Node B (NR NB), a network node, a 5G NB, an eNB, etc.). The base station or DU may communicate with a set of UEs on a downlink channel (e.g., for transmission from the base station or to the UE) and an uplink channel (e.g., for transmission from the UE to the base station or distributed unit).

[0005] These multi-connectivity technologies are adopted in various telecommunications standards to provide a common protocol that enables different wireless devices to communicate at the urban, national, regional, and even global scales. An example of a nascent telecommunications standard is New Radio (NR), such as 5G wireless access. NR is a set of extensions to the LTE mobile standard published by the 3rd Generation Partnership Project (3GPP®). It is designed to better support mobile broadband Internet access by improving spectral efficiency, reducing costs, enhancing services, utilizing new spectrum, and integrating more gracefully with other open standards that use OFDMA with a cyclic prefix (CP) on the downlink (DL) and uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] However, as the demand for mobile broadband access continues to increase, further improvements in NR technology are needed. Preferably, these improvements should be applicable to other multi-connectivity technologies and the telecommunications standards that use these technologies.

MEANS FOR SOLVING THE PROBLEMS

[0007] The systems, methods, and devices of the present disclosure each have several aspects, and only a single one of those aspects bears its desirable attributes. Without limiting the scope of the present disclosure as represented by the following claims, several features are briefly described herein. After considering this description and particularly after reading the section entitled "DETAILED DESCRIPTION OF THE INVENTION," it will be understood how the features of the present disclosure bring advantages, including improved communication between an access point and a station in a wireless network.

[0008] Some aspects of the present disclosure generally relate to methods and apparatuses for optimizing the delivery of data to and / or from user equipment in an inactive network state.

[0009] Aspects of the present disclosure provide a method for wireless communication by a user equipment (UE). The method generally includes generating a message having uplink data encrypted using a first key and a second key derived based on first UE identification information encrypted using the first key and information obtained from a first base station in a first cell before transitioning to that state, while a dedicated resource is not allocated to the UE; and transmitting the message to a second base station in a second cell.

[0010] Aspects of the present disclosure provide a method for wireless communication by a serving base station. The method generally includes receiving, from a user equipment in a state where a dedicated resource is not allocated to the UE, a message having uplink data encrypted using a first key and a second key derived by the UE based on first UE identification information encrypted using the first key and information obtained from another base station in a first cell before the UE transitions to that state; sending a request to another base station to transmit the UE's context to the serving base station; receiving a response to the request, the response including information regarding the second key; and decrypting the uplink data using the second key.

[0011] Aspects of the present disclosure provide a method for wireless communication by an anchor base station. The method generally includes providing, to a UE configured using a first key used to encrypt uplink data to be sent to another base station while the user equipment is in a state where a dedicated resource is not allocated to the UE, information for deriving a second key; receiving, from another base station, a request to transmit the UE's context from the anchor base station to another base station; and transmitting a response to the request, the response including information regarding the second key.

[0012] Aspects of the present disclosure provide a method for wireless communication by a user equipment (UE). The method generally includes deriving a first key while in a first state in which dedicated resources are allocated to the UE, generating a first message having uplink data encrypted using first UE identification information and the first key while in a second state in which dedicated resources are not allocated to the UE, transmitting the message to a second base station within a second cell, deriving a second key based on information obtained from the second base station, generating a second message having uplink data encrypted using the second key while in the second state in which dedicated resources are not allocated to the UE, and transmitting the message to the second base station within the second cell.

[0013] Aspects of the present disclosure provide a method for wireless communication by a serving base station. The method generally includes receiving, from a user equipment in a state in which dedicated resources are not allocated to the UE, a first message having uplink data encrypted using first UE identification information and a first key, forwarding the message to another base station, participating in a handover from the other base station to the serving base station, configuring the UE using second UE identification information and information for deriving a second key, and receiving, from the UE, a second message having uplink data encrypted using the second UE identification information and the second key.

[0014] Aspects of the present disclosure provide a method for wireless communication by an anchor base station. The method generally includes placing a user equipment (UE) in a state in which dedicated resources are not allocated to the UE, where the UE is configured using a first key, receiving, from a serving base station, a first message having uplink data encrypted by the UE using first UE identification information and the first key, and determining whether to transmit the UE's context to the serving base station.

[0015] Aspects generally include methods, apparatuses, systems, computer-readable media, and processing systems that are described in detail herein with reference to the accompanying drawings and shown by the accompanying drawings.

[0016] To achieve the above object and related objects, one or more aspects include the features that are described in detail below and pointed out particularly in the claims. The following description and the accompanying drawings detail some exemplary features of one or more aspects. However, these features represent only some of the various ways in which the principles of the various aspects may be utilized, and this description is intended to include all such aspects and their equivalents.

[0017] For a better understanding of the above features of the present disclosure, a more specific description, briefly summarized above, may be made by reference to the aspects, some of which are shown in the accompanying drawings. However, it should be noted that since this description may lead to other equally effective aspects, the accompanying drawings show only some exemplary aspects of the present disclosure and should not be considered as limiting the scope of the present disclosure.

Brief Description of the Drawings

[0018]

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[0019] For ease of understanding, where possible, the same reference numbers are used to denote the same elements common to the figures. It is contemplated that elements disclosed in one aspect may be advantageously utilized in other aspects without particular recitation.

[0020] Aspects of the present disclosure provide apparatus, methods, systems, and computer-readable media for New Radio (NR) (New Radio Access Technology or 5G technology).

[0021] NR can support various wireless communication services such as wide bandwidth (e.g., exceeding 80 MHz) targeted for enhanced mobile broadband (eMBB), high carrier frequencies (e.g., 60 GHz) targeted for millimeter wave (mmW), non-backward compatible MTC techniques targeted for massive MTC (mMTC), and / or ultra reliable low latency communication (URLLC) targeted for mission critical targets. These services may include latency requirements and reliability requirements. These services may also have different transmission time intervals (TTIs) to meet their respective quality of service (QoS) requirements. In addition, these services may coexist in the same subframe.

[0022] Aspects of the present disclosure relate to optimizing the delivery of data to and / or from a UE in a non-active network state.

[0023] The following description provides examples and is not intended to limit the scope, applicability, or examples set forth in the claims. Modifications may be made to the functions and configurations of the elements described without departing from the scope of the present disclosure. Various examples may appropriately omit, substitute, or add various procedures or components. For example, the methods described may be performed in an order different from the order described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in some other examples. For example, an apparatus may be implemented or a method may be practiced using any number of aspects described herein. Additionally, the scope of the present disclosure is intended to include such apparatus or methods practiced using other structures, functions, or structures and functions in addition to or other than the various aspects of the present disclosure described herein. It should be understood that any aspect of the present disclosure disclosed herein may be embodied by one or more elements of the claims. The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" should not necessarily be construed as preferred or advantageous over other aspects.

[0024] The techniques described in this specification may be used in various wireless communication networks such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network may implement wireless technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA (registered trademark)) and other variants of CDMA. cdma2000 targets the IS-2000 standard, IS-95 standard, and IS-856 standard. A TDMA network may implement wireless technologies such as Global System for Mobile Communications (GSM (registered trademark)). An OFDMA network may implement wireless technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of the Universal Mobile Telecommunications System (UMTS). NR is a newly emerging wireless communication technology being developed together with the 5G Technology Forum (5GTF). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM (registered trademark) are described in documents by a group called the "3rd Generation Partnership Project" (3GPP (registered trademark)). cdma2000 and UMB are described in documents by a group called the "3rd Generation Partnership Project 2" (3GPP2). The techniques described in this specification may be used in the above-mentioned wireless networks and wireless technologies, as well as other wireless networks and wireless technologies. For clarity, although aspects may be described herein using terms generally associated with 3G and / or 4G wireless technologies, aspects of the present disclosure may be applicable in other generation-based communication systems such as those after 5G, including NR technology.

[0025] Exemplary wireless communication system As shown in FIG. 1, an exemplary wireless network 100, such as a New Radio (NR) or 5G network, in which aspects of the present disclosure may be implemented to enable, for example, connection sessions and Internet Protocol (IP) establishment, will be described in more detail below.

[0026] As shown in FIG. 1, the wireless network 100 may include several BSs 110 and other network entities. A BS may be a station that communicates with a UE. Each BS 110 may provide communication coverage for a particular geographic area. In 3GPP (registered trademark), the term "cell" may refer to the coverage area of the Node B and / or Node B subsystem serving this coverage area, depending on the context in which this term is used. In an NR system, terms such as "cell" and eNB, Node B, 5G NB, AP, NR BS, or TRP may be interchangeable. In some examples, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of the mobile base station. In some examples, the base stations may be interconnected with each other within the wireless network 100 and / or with one or more other base stations or network nodes (not shown) through various types of backhaul interfaces, such as direct physical connections, virtual networks, using any suitable transport network.

[0027] Generally, any number of wireless networks may be deployed in a given geographical area. Each wireless network may support a specific radio access technology (RAT) and may operate at one or more frequencies. RAT may also be referred to as wireless technology, air interface, etc. Frequencies may also be referred to as carriers, frequency channels, etc. Each frequency may support a single RAT in a given geographical area to avoid interference between wireless networks of different RATs. In some cases, an NR RAT network or a 5G RAT network may be deployed.

[0028] A BS may provide communication coverage for macrocells, picocells, femtocells, and / or other types of cells. A macrocell can cover a relatively large geographical area (e.g., several kilometers in radius) and may enable unrestricted access by UEs subscribed to the service. A picocell can cover a relatively small geographical area and may enable unrestricted access by UEs subscribed to the service. A femtocell can cover a relatively small geographical area (e.g., a home) and may enable restricted access by UEs associated with the femtocell (e.g., UEs within a closed subscriber group (CSG), UEs for users within a home, etc.). A BS for a macrocell may sometimes be called a macro BS. A BS for a picocell may sometimes be called a pico BS. A BS for a femtocell may sometimes be called a femto BS or a home BS. In the example shown in FIG. 1, BSs 110a, 110b, and 110c may each be a macro BS for macrocells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for picocell 102x. BSs 110y and 110z may each be a femto BS for femtocells 102y and 102z, respectively. A BS may support one or more (e.g., three) cells.

[0029] Wireless network 100 may also include relay stations. A relay station is a station that receives transmissions of data and / or other information from an upstream station (e.g., a BS or a UE) and sends transmissions of data and / or other information to a downstream station (e.g., a UE or a BS). Also, the relay station may be a UE that relays transmissions for other UEs. In the example shown in FIG. 1, relay station 110r can communicate with BS110a and UE120r to facilitate communication between BS110a and UE120r. A relay station may also be referred to as a relay BS, a relay, etc.

[0030] Wireless network 100 can be a heterogeneous network including different types of BSs, such as macro BSs, pico BSs, femto BSs, relays, etc. These different types of BSs may have different transmission power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, a macro BS may have a high transmission power level (e.g., 20 watts), while pico BSs, femto BSs, and relays may have lower transmission power levels (e.g., 1 watt).

[0031] Wireless network 100 may support synchronous operation or asynchronous operation. In the case of synchronous operation, BSs can have similar frame timings, and transmissions from different BSs can be approximately time-aligned. In the case of asynchronous operation, BSs may have different frame timings, and transmissions from different BSs may not be time-aligned. The techniques described in this specification may be used for both synchronous and asynchronous operations.

[0032] Network controller 130 can communicate with a set of BSs and perform adjustments and controls for these BSs. Network controller 130 can communicate with BS110 via a backhaul. BS110s can also communicate with each other, for example, directly or indirectly via a wireless backhaul or a wired backhaul.

[0033] UE 120 (e.g., 120x, 120y, etc.) may be distributed throughout the wireless network 100, and each UE may be stationary or mobile. The UE may be a mobile station, a terminal, an access terminal, a subscriber unit, a station, a customer premises equipment (CPE), a cellular phone, a smartphone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a game device, a netbook, a smartbook, an ultrabook, a medical device or instrument, a biosensor / device, a smartwatch, smart clothing, smart glasses, a smart list band, wearable devices such as smart jewelry (e.g., smart rings, smart bracelets, etc.), entertainment devices (e.g., music devices, video devices, satellite radio, etc.), vehicle components or vehicle sensors, smart meters / sensors, industrial production equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless medium or a wired medium. Some UEs may be regarded as evolved devices or machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC UEs and eMTC UEs can communicate with a BS, another device (e.g., a remote device), or some other entity, including, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc. The wireless node may provide connectivity to a network (e.g., a wide area network such as the Internet or a cellular network) or for a network via, for example, a wired communication link or a wireless communication link. Some UEs may be regarded as Internet of Things (IoT) devices.

[0034] In FIG. 1, the solid line with double arrows indicates the desired transmission between the UE and the serving BS, where the serving BS is the BS designated to serve the UE on the downlink and / or uplink. The dashed line with double arrows indicates the interfering transmission between the UE and the BS.

[0035] Certain wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into a plurality of (K) orthogonal subcarriers, also commonly referred to as tones, bins, etc. Each subcarrier can be modulated with data. Generally, modulation symbols are sent in the frequency domain for OFDM and in the time domain for SC-FDM. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may depend on the system bandwidth. For example, the subcarrier spacing may be 15 kHz, and the smallest resource allocation (referred to as a "resource block") may be 12 subcarriers (or 180 kHz). As a result, the nominal FFT size can be equal to 128, 256, 512, 1024, or 2048 for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidth can also be divided into subbands. For example, a subband can cover 1.08 MHz (i.e., 6 resource blocks), and there can be 1, 2, 4, 8, or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0036] The example aspects described herein may be associated with LTE technology, but aspects of the present disclosure may be applicable to other wireless communication systems such as NR. NR may include support for using OFDM with CP on the uplink and downlink and for half-duplex operation using time-division duplexing (TDD). A single component carrier bandwidth of 100 MHz may be supported. An NR resource block may span 12 subcarriers with a subcarrier bandwidth of 75 kHz over a duration of 0.1 ms. Each radio frame may be composed of 50 subframes having a length of 10 ms. As a result, each subframe may have a length of 0.2 ms. Each subframe may indicate a link direction for data transmission (i.e., DL or UL), and the link direction for each subframe may be switched dynamically. Each subframe may include DL / UL data as well as DL / UL control data. UL subframes and DL subframes for NR may be as described in more detail below with respect to FIGS. 6 and 7. Beamforming may be supported and the beam direction may be configured dynamically. MIMO transmission using precoding may also be supported. The MIMO configuration in the DL may support up to 8 transmit antennas with multi-layer DL transmission using up to 8 streams and up to 2 streams per UE. Multi-layer transmission using up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported using up to 8 serving cells. Alternatively, NR may support different air interfaces other than OFDM-based. The NR network may include entities such as a CU and / or a DU.

[0037] In some examples, access to the air interface may be scheduled, and a scheduling entity (e.g., a base station) may allocate resources for communication among some or all of the devices and apparatuses within its service area or cell. In the present disclosure, as further described below, a scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, a subordinate entity utilizes the resources allocated by the scheduling entity. A base station is not the only entity that may function as a scheduling entity. That is, in some examples, a UE may function as a scheduling entity that schedules resources for one or more subordinate entities (e.g., one or more other UEs). In this example, the UE functions as a scheduling entity, and other UEs utilize the resources scheduled by the UE for wireless communication. A UE may function as a scheduling entity in a peer-to-peer (P2P) network and / or in a mesh network. In a mesh network example, in addition to communicating with a scheduling entity, UEs may in some cases communicate directly with each other.

[0038] Accordingly, in a wireless communication network having a cellular configuration, a P2P configuration, and a mesh configuration, with scheduled access to time-frequency resources, a scheduling entity and one or more subordinate entities may communicate using the scheduled resources.

[0039] As described above, the RAN may include a CU and a DU. An NR BS (e.g., eNB, 5G Node B, Node B, Transmission and Reception Point (TRP), Access Point (AP)) may correspond to one or more BSs. An NR cell may be configured as an access cell (ACell) or a data-only cell (DCell). For example, a RAN (e.g., a centralized unit or a distributed unit) can configure a cell. A DCell may be used for carrier aggregation or dual connectivity but may not be used for initial access, cell selection / reselection, or handover. In some cases, a DCell may not transmit a synchronization signal, and in some cases, a DCell may transmit an SS. The NR BS may transmit a downlink signal indicating the cell type to the UE. Based on the cell type indication, the UE may communicate with the NR BS. For example, the UE may determine an NR BS to be considered for cell selection, access, handover, and / or measurement based on the indicated cell type.

[0040] FIG. 2 shows an exemplary logical architecture of a distributed radio access network (RAN) 200 that may be implemented within the wireless communication system shown in FIG. 1. The 5G access node 206 may include an access node controller (ANC) 202. The ANC may be a centralized unit (CU) of the distributed RAN 200. The backhaul interface to the next generation core network (NG-CN) 204 may terminate at the ANC. The backhaul interface to a neighboring next generation access node (NG-AN) may terminate at the ANC. The ANC may include one or more TRPs 208 (BS, NR BS, Node B, 5G NB, AP, or may be called by some other term). As described above, a TRP may be used interchangeably with a "cell".

[0041] TRP208 may be a DU. The TRP may be connected to one ANC (ANC202) or may be connected to two or more ANCs (not shown). For example, for RAN sharing, radio as a service (RaaS), and service-specific ANC placement, the TRP may be connected to two or more ANCs. The TRP may include one or more antenna ports. The TRP may be configured to serve traffic to the UE individually (e.g., dynamically select) or together (e.g., co-transmit).

[0042] The local architecture 200 may be used to indicate the fronthaul definition. An architecture that supports fronthauling solutions across different deployment types may be defined. For example, the architecture may be based on the transmission network capabilities (e.g., bandwidth, latency, and / or jitter).

[0043] The architecture may share features and / or components with LTE. According to an aspect, the next-generation AN (NG-AN) 210 may support dual connectivity with NR. The NG-AN may share a common fronthaul for LTE and NR.

[0044] The architecture may enable cooperation between TRPs 208. For example, the cooperation may be preset within the TRP and / or may be preset across the TRPs via the ANC202. According to an aspect, there may be no need for / absence of an interface between TRPs.

[0045] According to an aspect, there may be a dynamic configuration of split logical functions within architecture 200. As will be described in more detail with reference to FIG. 5, the Radio Resource Control (RRC) layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer, the Medium Access Control (MAC) layer, and the Physical (PHY) layer may be adaptively arranged in the DU or the CU (e.g., the TRP or the ANC respectively). According to some aspects, the BS may include a Centralized Unit (CU) (e.g., ANC202) and / or one or more Distributed Units (e.g., one or more TRP208).

[0046] FIG. 3 shows an exemplary physical architecture of a distributed RAN 300 according to some aspects of the present disclosure. A Centralized Core Network Unit (C-CU) 302 may host core network functions. The C-CU may be centrally located. The C-CU function may be offloaded (e.g., to Advanced Wireless Services (AWS)) to handle peak capacity.

[0047] A Centralized RAN Unit (C-RU) 304 may host one or more ANC functions. In some cases, the C-RU may locally host core network functions. The C-RU may have a distributed arrangement. The C-RU may be closer to the network edge.

[0048] A DU 306 may host one or more TRPs (Edge Node (EN), Edge Unit (EU), Radio Head (RH), Smart Radio Head (SRH), etc.). The DU may be located at the edge of a network with radio frequency (RF) functions.

[0049] FIG. 4 shows exemplary components of the BS 110 and UE 120 shown in FIG. 1 that may be used to implement aspects of the present disclosure. As described above, the BS may include a TRP. One or more components of the BS 110 and UE 120 may be used to practice aspects of the present disclosure. For example, the antenna 452, Tx / Rx 222, processors 466, 458, 464, and / or controller / processor 480 of the UE 120, and / or the antenna 434, processors 430, 420, 438, and / or controller / processor 440 of the BS 110 may be used to perform the operations described herein and shown with reference to FIG. 13.

[0050] FIG. 4 shows a block diagram of the designs of the BS 110 and UE 120, which may be one of the BSs and one of the UEs in FIG. 1. For the case of a limited connection scenario, the base station 110 may be the macro BS 110c in FIG. 1, and the UE 120 may be the UE 120y. The base station 110 may also be some other type of base station. The base station 110 may include antennas 434a to 434t, and the UE 120 may include antennas 452a to 452r.

[0051] At base station 110, transmission processor 420 may receive data from data source 412 and control information from controller / processor 440. The control information may relate to, for example, the physical broadcast channel (PBCH), the physical control format indicator channel (PCFICH), the physical hybrid ARQ indicator channel (PHICH), the physical downlink control channel (PDCCH), etc. The data may relate to, for example, the physical downlink shared channel (PDSCH), etc. Processor 420 can process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Processor 420 can also generate reference symbols, for example, for the PSS, SSS, and cell-specific reference signals. Transmission (TX) multiple-input multiple-output (MIMO) processor 430 can perform spatial processing (e.g., precoding) on the data symbols, control symbols, and / or reference symbols, if applicable, and provide the output symbol stream to modulators (MOD) 432a - 432t. For example, TX MIMO processor 430 can perform some of the aspects described herein for RS multiplexing. Each modulator 432 can process its respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 432 can further process the output sample stream (e.g., convert to analog, amplify, filter, and upconvert) to obtain a downlink signal. The downlink signals from modulators 432a - 432t may be transmitted via antennas 434a - 434t, respectively.

[0052] In UE120, antennas 452a to 452r can receive downlink signals from base station 110 and can provide the received signals to respective demodulators (DEMOD) 454a to 454r. Each demodulator 454 can adjust (e.g., filter, amplify, down-convert, and digitize) the respective received signal to obtain input samples. Each demodulator 454 can further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. The MIMO detector 456 can obtain received symbols from all demodulators 454a to 454r, perform MIMO detection on the received symbols if applicable, and provide the detected symbols. For example, the MIMO detector 456 can provide the detected RS transmitted using the techniques described herein. The receiving processor 458 can process the detected symbols (e.g., demodulate, de-interleave, and decode), provide the decoded data for UE120 to the data sink 460, and provide the decoded control information to the controller / processor 480.

[0053] On the uplink, at UE120, transmission processor 464 may receive and process data from data source 462 (e.g., for physical uplink shared channel (PUSCH)) and control information from controller / processor 480 (e.g., for physical uplink control channel (PUCCH)). Transmission processor 464 may also generate reference symbols for reference signals. Symbols from transmission processor 464 may be precoded by TX MIMO processor 466, if applicable, and further processed by demodulators 454a - 454r (e.g., for SC - FDM) and transmitted to base station 110. At BS110, the uplink signal from UE120 is received by antenna 434, processed by modulator 432, detected by MIMO detector 436, if applicable, and further processed by receive processor 438 to obtain the decoded data and control information sent by UE120. Receive processor 438 may provide the decoded data to data sink 439 and the decoded control information to controller / processor 440.

[0054] Controllers / processors 440 and 480 may each direct operations at base station 110 and UE120, respectively. Processor 440 and / or other processors and modules at base station 110 may execute or direct, for example, the implementation of the functional blocks shown in FIG. 13 and / or other processes for the techniques described herein. Processors 480 and / or other processors and modules at UE120 may also execute or direct processes for the techniques described herein. Memories 442 and 482 may each store data and program code for BS110 and UE120, respectively. Scheduler 444 may schedule UEs for data transmission on the downlink and / or uplink.

[0055] FIG. 5 shows a diagram 500 illustrating an example for implementing a communication protocol stack according to an aspect of the present disclosure. The illustrated communication protocol stack may be implemented by a device operating within a 5G system (e.g., a system supporting uplink-based mobility). FIG. 500 shows a communication protocol stack including a Radio Resource Control (RRC) layer 510, a Packet Data Convergence Protocol (PDCP) layer 515, a Radio Link Control (RLC) layer 520, a Medium Access Control (MAC) layer 525, and a Physical (PHY) layer 530. In various examples, the layers of the protocol stack may be implemented as individual software modules, portions of a processor or ASIC, portions of non-collocated devices connected by a communication link, or various combinations thereof. Collocated and non-collocated implementations may be used, for example, within a protocol stack for a network access device (e.g., an AN, a CU, and / or a DU) or a UE.

[0056] A first option 505-a shows a split implementation of the protocol stack where the implementation of the protocol stack is split between a centralized network access device (e.g., ANC202 of FIG. 2) and a distributed network access device (e.g., DU208 of FIG. 2). In the first option 505-a, the RRC layer 510 and the PDCP layer 515 may be implemented by an aggregation unit, and the RLC layer 520, the MAC layer 525, and the PHY layer 530 may be implemented by a DU. In various examples, the CU and the DU may be collocated or may not be collocated. The first option 505-a may be useful in a macrocell deployment, a microcell deployment, or a picocell deployment.

[0057] The second option 505-b shows an integrated implementation form of the protocol stack where the protocol stack is implemented within a single network access device (e.g., access node (AN), new radio base station (NB BS), new radio node B (NR NB), network node (NN), etc.). In the second option, the RRC layer 510, PDCP layer 515, RLC layer 520, MAC layer 525, and PHY layer 530 can each be implemented by the AN. The second option 505-b may be useful in a femtocell deployment.

[0058] Regardless of whether the network access device implements part or all of the protocol stack, the UE may implement the entire protocol stack (e.g., RRC layer 510, PDCP layer 515, RLC layer 520, MAC layer 525, and PHY layer 530).

[0059] FIG. 6 is a diagram 600 showing an example of a DL-centered subframe. The DL-centered subframe may include a control portion 602. The control portion 602 may be present in the first or start portion of the DL-centered subframe. The control portion 602 may include various scheduling information and / or control information corresponding to various portions of the DL-centered subframe. In some configurations, the control portion 602 may be a physical DL control channel (PDCCH), as shown in FIG. 6. The DL-centered subframe may also include a DL data portion 604. The DL data portion 604 may sometimes be referred to as the payload of the DL-centered subframe. The DL data portion 604 may include communication resources used to communicate DL data from a scheduling entity (e.g., UE or BS) to a dependent entity (e.g., UE). In some configurations, the DL data portion 604 may be a physical DL shared channel (PDSCH).

[0060] The subframe of the DL center may also include a common UL portion 606. The common UL portion 606 may sometimes be referred to as a UL burst, a common UL burst, and / or various other appropriate terms. The common UL portion 606 may include feedback information corresponding to various other parts of the subframe of the DL center. For example, the common UL portion 606 may include feedback information corresponding to the control portion 602. Non-limiting examples of the feedback information may include an ACK signal, a NACK signal, a HARQ indicator, and / or various other appropriate types of information. The common UL portion 606 may include additional or alternative information such as random access channel (RACH) procedures, information regarding scheduling requests (SR), and various other appropriate types of information. As shown in FIG. 6, the end of the DL data portion 604 may be separated in time from the start of the common UL portion 606. This time separation may sometimes be referred to as a gap, a guard period, a guard interval, and / or various other appropriate terms. This separation provides time for the switching from DL communication (e.g., the reception operation by a subordinate entity (e.g., a UE)) to UL communication (e.g., the transmission by a subordinate entity (e.g., a UE)). The above is only an example of a subframe of the DL center, and those skilled in the art will understand that alternative structures having similar features may exist without necessarily departing from the aspects described herein.

[0061] FIG. 7 is a diagram 700 showing an example of a UL center subframe. The UL center subframe may include a control portion 702. The control portion 702 may be present in the first or start portion of the UL center subframe. The control portion 702 in FIG. 7 may be similar to the control portion described above with reference to FIG. 6. The UL center subframe may also include a UL data portion 704. The UL data portion 704 may sometimes be referred to as the payload of the UL center subframe. The UL portion may refer to communication resources utilized for communicating UL data from a subordinate entity (e.g., a UE) to a scheduling entity (e.g., a UE or a BS). In some configurations, the control portion 702 may be a physical DL control channel (PDCCH).

[0062] As shown in FIG. 7, the end of the control portion 702 can be temporally separated from the start of the UL data portion 704. This temporal separation may sometimes be referred to by various other appropriate terms such as gap, guard period, guard interval, and / or the like. This separation provides time for the switch from DL communication (e.g., a reception operation by a scheduling entity) to UL communication (e.g., a transmission by a scheduling entity). The UL-centered subframe may also include a common UL portion 706. The common UL portion 706 in FIG. 7 may be similar to the common UL portion 606 described above with reference to FIG. 6. The common UL portion 706 may alternatively or additionally include information regarding a channel quality indicator (CQI), a sounding reference signal (SRS), and various other appropriate types of information. The above is only an example of a UL-centered subframe, and those skilled in the art will understand that alternative structures having similar characteristics may exist without necessarily departing from the aspects described herein.

[0063] In some situations, two or more dependent entities (e.g., UEs) can communicate with each other using sidelink signals. Real-world application examples of such sidelink communication may include public safety, proximity services, relay from UE to network, vehicle-to-vehicle (V2V) communication, Internet of Everything (IoE) communication, IoT communication, mission-critical mesh, and / or various other appropriate application examples. Generally, a sidelink signal may refer to a signal communicated from one dependent entity (e.g., UE1) to another dependent entity (e.g., UE2) without relaying the communication through a scheduling entity (e.g., UE or BS), although the scheduling entity may be utilized for scheduling and / or control. In some examples, the sidelink signal may be communicated using a licensed spectrum (unlike a wireless local area network which typically uses unlicensed spectrum).

[0064] The UE can operate in various radio resource configurations, including configurations related to transmitting pilots using a dedicated set of resources (e.g., in the Radio Resource Control (RRC) dedicated state) or configurations related to transmitting pilots using a common set of resources (e.g., in the RRC common state). When operating in the RRC dedicated state, the UE may select a dedicated set of resources to transmit pilot signals to the network. When operating in the RRC common state, the UE may select a common set of resources to transmit pilot signals to the network. In either case, the pilot signals transmitted by the UE can be received by one or more network access devices, such as the AN or DU, or parts thereof. Each receiving network access device is configured to receive and measure the pilot signals transmitted on the common set of resources and also the pilot signals transmitted on the dedicated set of resources allocated to the UE that is a member of the monitoring set of network access devices for the UE. One or more of the receiving network access devices, or the CU to which the receiving network access devices transmit the measurement values of the pilot signals, may use the measurement values to identify the serving cell for the UE or to initiate a change of the serving cell for one or more of the UEs.

[0065] Small data transmission in non-active state UEs There are various IoT application examples involving relatively small amounts of data exchange. For example, measurement and alarm application examples generally involve a small amount of mobile originated (MO) data, while various queries, update notifications, actuator activations, etc. involve a small amount of mobile terminated (MT) data. Unfortunately, establishing a connection between a mobile device and a network involves a large overhead (for a small amount of data). In some cases, the UE may be placed in a non-active "RAN control" state that represents an intermediate between the connected state and the idle state. For example, a UE in a non-active "RAN control" connection state (e.g., RRC_INACTIVE state) has · Cell reselection mobility, · CN-NR RAN connection (both C / U planes) is established for the UE, · The UE AS context is stored in at least one gNB and in the UE, · Paging is initiated by the NR RAN, · RAN-based notification areas are managed by the NR RAN, · The NR RAN knows the RAN-based notification area to which the UE belongs, and · The UE does not have dedicated resources, and may have various characteristics such as the above.

[0066] Enabling data transmission to or from a UE (or other type of mobile device) in the RRC_INACTIVE state makes sense if the UE has a small amount of data to transmit and the RAN has no data or only a small amount of data to transmit while the UE is in that state. If either the UE or the RAN has subsequent data to transmit, the overhead to transition to an active connection state (e.g., RRC_CONNECTED state) may be justified, whereby the data can be sent using dedicated resources.

[0067] In one scenario, UL data transmission may be supported without RRC signaling without initiating a transition to active (this may be referred to as Option A). An alternative scenario is to support UL data transmission using RRC signaling but without initiating a transition to active (this may be referred to as Option B).

[0068] Aspects of the present disclosure may be applied to enable small uplink transmission in various scenarios, such as the scenario shown in FIG. 8. As shown, such scenarios may include a first scenario, Scenario 1, where the UE sends the uplink transmission within the same small cell as (where it was previously connected). In a second scenario, Scenario 2, the UE may send the uplink transmission to a different cell covered by the same PDCP entity (such that, for example, no PDCP entity reconfiguration is required) (different from the previously connected cell). In a third scenario, Scenario 3, the UE may send the uplink transmission to a different cell within a different PDCP entity (such that, for example, PDCP reconfiguration is required).

[0069] Exemplary optimizations for data delivery to / from a UE in the non - active state Aspects of the present disclosure provide support for UL data transmission that may consider changes to the first option (Option A) for small UL data delivery described above. One scenario described herein may consider a serving gNB - based solution for small UL data transmission while the UE is in the RRC_INACTIVE state (for example, because the serving gNB may request the transfer of UE context). Another scenario may consider an anchor gNB - based solution (for example, because the anchor gNB may make a decision on whether to transfer the UE context).

[0070] As used herein, the term anchor generally refers to a base station (e.g., eNB / gNB) to which a non-active UE had previously connected and which has a UE context for subsequent communication. On the other hand, the term serving generally refers to the base station that is currently communicating directly with the UE (and it may or may not be the anchor).

[0071] Figures 9-11 are flow diagrams of operations that may be performed by an anchor base station, a UE, and a serving base station, respectively, for a serving gNB-based solution for small UL data transmission while the UE is in a state of not having dedicated resources.

[0072] In other words, FIG. 9 shows an exemplary operation 900 that may be performed by an anchor base station to enable small uplink data transmission, according to some aspects of the present disclosure.

[0073] Operation 900 begins at 902 by providing a UE configured to use a first key, which is used to encrypt uplink data that the UE is to send to another base station while the UE is in a state where dedicated resources are not allocated to the UE, with information for deriving a second key. For example, the state may be a radio resource control (RRC) state, a substate of the RRC state, or a configuration of the RRC state.

[0074] At 904, the anchor base station receives a request from another base station to transfer the UE's context from the anchor base station to the other base station. At 906, the anchor base station transmits a response to the request, and the response includes information regarding the second key.

[0075] FIG. 10 shows an exemplary operation 1000 that may be performed by a UE for small uplink data transmission, according to some aspects of the present disclosure. In other words, operation 1000 may be performed by a UE configured by an anchor base station performing operation 900 described above.

[0076] Operation 1000 starts, at 1002, by generating a message having uplink data encrypted using a first key and a second key derived based on information obtained from a first base station in a first cell before transitioning to that state, while in a state where dedicated resources are not allocated to the UE, for the first UE identification information encrypted using the first key. At 1004, the UE transmits the message to a second base station in a second cell.

[0077] FIG. 11 shows exemplary operations that may be performed by a serving base station to process small uplink data transmissions, according to some aspects of the present disclosure. In other words, operation 1100 may be performed by a base station serving a UE by executing operation 1000 described above.

[0078] Operation 1100 starts, at 1102, by receiving a message having uplink data encrypted using a first key and a second key derived by the UE based on information obtained from another base station in a first cell before the UE transitions to that state, from a user equipment in a state where dedicated resources are not allocated to the UE. At 1104, the serving base station sends a request to another base station to transmit the UE's context to the serving base station. At 1106, the serving base station receives a response to the request, and the response includes information regarding the second key. At 1108, the serving base station decrypts the uplink data using the second key.

[0079] FIG. 12 shows an exemplary data flow for small uplink data transmission according to the serving gNB-based option described in this specification. As shown, the UE may access the radio access network (RAN) via a serving gNB that may validate the UE via an anchor gNB. After validation, in some cases, a path switch may be performed (e.g., the context is transferred from the anchor gNB to the serving gNB). After the path switch, the UE may route UL data to the (New Generation) Core Network (NGCN) via the serving gNB.

[0080] As shown in the call flow diagram of FIG. 13, according to the serving gNB-based solution, the anchor gNB may provide the UE with a Next Hop Chaining Counter (NCC) for new security key derivation before the UE transitions to enter the RRC_INACTIVE state. Thus, the UE may maintain both the old key (e.g., previously derived) and the new key. By maintaining the old key after obtaining the new key, a mechanism for sending uplink data while the UE is in the RRC_INACTIVE state may be provided.

[0081] In Scenarios 1 and 2 (where the PDCP anchor does not change), the UE may send uplink data along with UE identification information (Resume ID) that is security protected using the old key in Msg3. In this case, context transfer / path switch is not required. The downlink data sent in response to the uplink transmission may also be security protected using the old key. Thus, in this case, additional downlink signaling for reconfiguring the UE using a new Resume ID or a new security ID is not required.

[0082] As shown in FIG. 13, the UE and the serving gNB may start a timer after Msg3 (sent by the UE). The UE may continuously monitor DL transmissions while the timer is running.

[0083] As shown in the figure, after receiving UL data encrypted with a new key, the serving gNB may request context transfer (providing the UE's old resume ID and short MAC identifier to verify the UE by the anchor gNB). After the context is transferred (step 7), the new serving gNB may send DL RRC signaling to reconfigure the UE using, for example, the UE's new context location, status indication, and a new resume ID reflecting the next new key (for encrypting uplink data).

[0084] The UE may use the next new key for security protection when the UE starts uplink data transmission within the next new cell (and). In other words, within the next new cell, the current (previous new) key becomes the old key, and the current next new key becomes the new key. As a result, in this approach, the UE maintains two sets of keys simultaneously.

[0085] As shown in the figure, the resume ID is not only assigned by the gNB when the gNB transitions the UE from RRC_CONNECTED to RRC_INACTIVE, but the resume ID is also always updated / reassigned after the UE context is transferred from the anchor gNB to the new serving gNB.

[0086] As shown in the figure, in the case of scenario 3 where the PDCP entity is relocated, in addition to UE verification via the resume ID (the anchor gNB cell ID within its cell, UE I-RNTI), the anchor gNB performs a short MAC-I protected by the stored old key for integrity protection (for example, the input is the anchor gNB cell ID within its cell, the serving gNB cell ID, UE I-RNTI).

[0087] As shown in the figure, the UL data in Msg3 may include UL small data protected by a new key for integrity and encryption, in addition to the resume ID and short MAC-I protected by the old key.

[0088] After the UE and the serving gNB send Msg3, they may start a timer. During the period when this timer is running, the UE may assume that there is an incoming call without paging by the serving gNB, so the UE will continuously monitor downlink transmissions. As shown in the figure, the serving gNB may trigger a context fetch by the resume ID and short MAC-I sent to the anchor gNB for the anchor gNB to verify the UE (for example, the anchor gNB verifies the UE using an old key).

[0089] As shown in the figure, if UE verification is successful, the UE context is transferred from the anchor gNB to the (new) serving gNB. A new security key is also transferred to the serving gNB. In this scenario, the path can also be switched to the new gNB in procedures similar to, for example, Xn handover. The serving gNB may derive a new security key used to decrypt UL small data using the new key, and the serving gNB may transfer the small data to the UPN.

[0090] As described above, during the timer operation period (after Msg3), the new serving gNB can send a DL App Ack (which is encrypted / protected for integrity by the new key) without paging.

[0091] Due to the UE context switch, the serving gNB can send downlink signaling protected by the new key to reconfigure the UE using, for example, the UE's new context memory area, the next new security key, and a new resume ID reflecting the status indication (for example, RRC_INACTIVE or RRC_CONNECTED).

[0092] In some cases, the serving gNB can also reject UE uplink transmissions, for example, by sending an RRC connection rejection message. This rejection message can be security protected with a new key and can include, for example, a latency, a new resume ID (reflecting the UE's new context location), and a new security key. In some cases, reconfiguring the UE with a new resume ID and security key is essential each time the context is transferred.

[0093] In some cases, information can be conveyed to enable applications for overload control and traffic prioritization. For example, since the RRC_INACTIVE state is NAS aware, the NAS can provide a cause value and / or call type to the application server (AS), enabling the AS to perform integrated access control (AC) based on the call type (and / or cause value) provided by the NAS. In some cases, the cause value can be carried within a MAC CE for network overload control and prioritization.

[0094] In the case of Scenario 3, the network can reject the UE via RRC signaling after the context is transferred from the anchor gNB to the serving gNB. In some cases, information can be conveyed to enable the network to determine whether and when the UE transitions to the RRC_CONNECTED state, for example, based on a data threshold that can be left to the network implementation form. For example, information can also be conveyed to enable the network to determine the UL grant size based on a buffer status report (BSR).

[0095] Figures 14 to 16 are flow diagrams of operations that can be performed by an anchor base station, a UE, and a serving base station, respectively, for what is sometimes referred to as an anchor gNB-based solution for small UL data transmission while the UE is in a state of not having dedicated resources.

[0096] Figure 14 shows an exemplary operation 1400 that can be performed by an anchor base station to enable small uplink data transmission according to some aspects of the present disclosure.

[0097] Operation 1400 starts, at 1402, by placing the user equipment (UE) in a state where dedicated resources are not allocated to the UE, and the UE is configured using a first key. At 1404, the anchor base station receives, from the serving base station, a first message having the first UE identification information and uplink data encrypted by the UE using the first key. At 1406, the anchor base station determines whether to transmit the UE context to the serving base station.

[0098] Figure 15 shows an exemplary operation that can be performed by a user equipment for small uplink data transmission according to some aspects of the present disclosure. In other words, operation 1500 can be performed by the UE configured by the anchor base station executing operation 1400 described above.

[0099] Operation 1500 starts, at 1502, by deriving a first key while in a first state where dedicated resources are allocated to the UE. At 1504, the UE generates a first message having the first UE identification information and uplink data encrypted using the first key while in a second state where dedicated resources are not allocated to the UE. At 1506, the UE transmits the message to a second base station within a second cell. At 1508, the UE derives a second key based on information obtained from the second base station. At 1510, the UE generates a second message having uplink data encrypted using the second key while in the second state where dedicated resources are not allocated to the UE. At 1512, the UE transmits the message to the second base station within the second cell.

[0100] FIG. 16 shows an exemplary operation that may be performed by a serving base station to process small uplink data transmission according to some aspects of the present disclosure. In other words, operation 1600 may be performed by a base station serving a UE by executing operation 1500 described above.

[0101] Operation 1600 begins, at 1602, by receiving, from a user equipment in a state where dedicated resources are not allocated to the UE, a first message having first UE identification information and uplink data encrypted using a first key. At 1604, the serving base station forwards the message to another base station. At 1606, the serving base station participates in a path switch from another base station to the serving base station. At 1608, the serving base station configures the UE using second UE identification information and information for deriving a second key. At 1610, the serving base station receives a second message having second UE identification information and uplink data encrypted using the second key from the UE.

[0102] FIG. 17 shows an exemplary data flow for small uplink data transmission according to some aspects of the present disclosure. As shown, a UE may access a radio access network (RAN) via a serving gNB that may authenticate the UE via an anchor gNB. After authentication, UE UL data may be routed to the NGCN via the anchor gNB.

[0103] FIGS. 18 and 19 show exemplary call flow diagrams for small uplink data transmission according to respective anchor gNB-based solutions with and without serving gNB assistance, according to some aspects of the present disclosure.

[0104] Generally, the serving gNB can operate in the RLC and lower layers. Therefore, the serving gNB can transfer UL PDCP data together with the resume ID to the anchor gNB for UE verification and data decoding / path designation to the NGC N. The anchor gNB can determine when to trigger a transfer HO to convey context / path switching to the serving gNB.

[0105] When the anchor gNB triggers context transfer to the serving gNB, the serving gNB can reconfigure the UE by DL RRC signaling using a new security key and resume ID after path switching. Therefore, the serving gNB becomes the new anchor gNB.

[0106] As shown in FIG. 18, the serving gNB can send assistance information (e.g., indicating that context transfer is preferred in step 5) to let the anchor gNB determine whether and when to transfer the context to the serving gNB.

[0107] In steps 10 to 18, the anchor gNB can determine to transfer the UE context to the serving gNB via a transfer handover procedure or a newly defined procedure (with context transfer). The trigger can be based on, for example, the need for the UE RRC state (or a lower state of the RRC state) to transition to the RRC_CONNECTED state according to an uplink transmission threshold, serving gNB assistance information (context transfer is preferred), etc.

[0108] There are various options that exist to apply overload control. For example, according to one option, there is no network-based overload control or prioritization (e.g., only UE-based AC is used). According to other options, air overload control and prioritization can be performed by the serving gNB. In some cases, the UE may carry the call type and / or cause value within the MAC CE (as explained for the serving gNB-based solution).

[0109] In some cases, RRC connection rejection may occur without path switching. In this case, the serving gNB can reject UE uplink transmission by sending an RRC connection rejection to the UE (in some cases, the latency may be carried within the RRC connection rejection). In this case, there is no path switching to the serving gNB, and the RRC connection rejection signaling is not protected by any security.

[0110] In another option, RRC connection rejection may occur (after) by path switching. The serving gNB may send a signal to trigger path switching to the anchor gNB. In this case, the serving gNB (which will become the anchor gNB) sends an RRC connection rejection with integrity protection to the UE. The UE may be configured with a resume ID and a new NCC after path switching.

[0111] As shown in Figure 19, in some cases, the serving gNB may transfer UL data without assistance information (e.g., without indicating a preference for context transfer).

[0112] Resume IDs and UL data protected with an old key, with or without serving gNB assistance, can be transferred to the anchor gNB for UE verification and path designation to the NGC N.

[0113] DL data sent in response to UL data received within the timer interval is encrypted by the anchor gNB and can be transferred to the serving gNB (the DL reception TID is allocated by the serving gNB in UL data transfer).

[0114] In some cases, the anchor gNB may determine whether to transfer the {NH, NCC} pair included in the Xn message to the serving gNB and when to transfer a handover (HO). When performing a transfer HO and path switch to the serving gNB, the serving gNB can reconfigure the UE using a new resume ID, a new NCC, a status indication, etc. If the serving gNB determines that the UE will trigger a serving gNB-based solution next time, the UE can be configured using the next NCC.

[0115] After the RRC reconfiguration is completed, the UL data is verified and can be routed to the NGC via the serving gNB (which will become the anchor gNB from now on).

[0116] As shown in Figure 20, in some cases, the anchor base station may select which (e.g., anchor gNB-based or serving gNB-based) solution is used for small uplink data transmission according to some aspects of the present disclosure. In some cases, this selection can be made when the anchor gNB determines to transition the UE to the RRC_INACTIVE state. As shown in the figure, the selection may be based on various factors such as UE service type, user preference, or operator configuration.

[0117] The methods disclosed herein include one or more steps or actions for implementing the described methods. The method steps and / or actions may be interchanged with each other without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of particular steps and / or actions may be modified without departing from the scope of the claims.

[0118] As used herein, the phrase "at least one of" in reference to a list of items refers to any combination of those items including a single member. As an example, "at least one of a, b, or c" includes a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination having multiple of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c, or a, b, and c in any other order).

[0119] The term "determining" as used herein encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, database or another data structure), ascertaining, etc. Further, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. Further, "determining" may include resolving, selecting, choosing, establishing, etc.

[0120] The foregoing description is provided 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 may be applied to other aspects. Accordingly, the claims are not intended to be limited to the aspects shown herein but are to be accorded the full scope consistent with the claim language, and references to singular elements are to be construed as meaning one or more unless explicitly stated otherwise. Unless otherwise specified, the term "some" refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those skilled in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, the disclosure herein is not dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. An element of a claim should not be construed under the provisions of 35 U.S.C. § 112, paragraph 6, unless the element is expressly recited using the phrase "means for" or, in the case of a method claim, the element is expressly recited using the phrase "step for".

[0121] The various operations of the methods described above may be performed by any suitable means capable of performing the corresponding functions. The means may include, but are not limited to, various hardware and / or software components and / or modules including a circuit, an application specific integrated circuit (ASIC), or a processor. In general, where there are operations shown in the figures, those operations may have corresponding means-plus-function components with similar numbers.

[0122] For example, the means for transmitting and / or receiving may include one or more of the transmission processor 420, TX MIMO processor 430, reception processor 438, or antenna 434 of the base station 110, and / or the transmission processor 464, TX MIMO processor 466, reception processor 458, or antenna 452 of the user equipment 120. Additionally, the means for generating, multiplexing, and / or applying may include one or more processors such as the controller / processor 440 of the base station 110 and / or the controller / processor 480 of the user equipment 120.

[0123] The various illustrative logical blocks, modules, and circuits described in connection with the present disclosure may be implemented or executed using a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0124] When implemented in hardware, an exemplary hardware configuration may include a processing system within the wireless node. The processing system may be implemented using a bus architecture. The bus may include any number of interconnecting buses and bridges, depending on the specific application of the processing system and overall design constraints. The bus may link together various circuits including a processor, a machine-readable medium, and a bus interface. The bus interface may be used to connect, among other things, a network adapter to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the case of user terminal 120 (see FIG. 1), a user interface (e.g., keypad, display, mouse, joystick, etc.) may be connected to the bus. The bus may link together various other circuits such as a timing source, peripherals, a voltage regulator, a power management circuit, etc., but these circuits are well known in the art and thus will not be described further. The processor may be implemented using one or more general-purpose processors and / or dedicated processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Those skilled in the art will recognize how best to implement the above-described functions of the processing system according to the specific application and overall design constraints imposed on the overall system.

[0125] When implemented in software, the functions can be stored on a computer-readable medium as one or more instructions or code, or can be transmitted via a computer-readable medium. Software should be broadly construed to mean instructions, data, or any combination thereof, whether called software, firmware, middleware, microcode, hardware description language, or by any other name. A computer-readable medium includes both a computer storage medium and a communication medium that facilitates transfer of a computer program from one place to another. A processor may be responsible for managing buses and general processing, including execution of software modules stored on a machine-readable storage medium. A computer-readable storage medium may be coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integral to the processor. By way of example, a machine-readable medium may include a transmission line, a carrier wave modulated by data, and / or a computer-readable storage medium storing instructions separate from a wireless node, all of which may be accessed by a processor via a bus interface. Alternatively or additionally, a machine-readable medium or any portion thereof may be integrated with the processor, similar to a cache and / or a general-purpose register file. Examples of machine-readable storage media can include, by way of example only, RAM (Random Access Memory), flash memory, ROM (Read Only Memory), PROM (Programmable Read Only Memory), EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), registers, magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof. A machine-readable medium may be embodied within a computer program product.

[0126] A software module can contain a single instruction or many instructions and can be distributed across several different code segments, across different programs, and across multiple storage media. A computer-readable medium may contain several software modules. A software module contains instructions that, when executed by an apparatus such as a processor, cause a processing system to perform various functions. A software module may include a transmitting module and a receiving module. Each software module may reside within a single storage device or may be distributed across multiple storage devices. By way of example, when a trigger event occurs, a software module may be loaded from a hard drive into RAM. During execution of a software module, the processor may load some of the instructions into a cache to increase access speed. One or more cache lines may then be loaded into a general-purpose register file for execution by the processor. When reference is made hereinafter to the functions of a software module, it will be understood that such functions are implemented by the processor when executing instructions from that software module.

[0127] Also, any connection is properly termed a computer-readable medium. For example, when software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared (IR), wireless, and microwave, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, wireless, and microwave are included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray (registered trademark) disc, where disk typically magnetically reproduces data and disc optically reproduces data using a laser. Thus, in some aspects, a computer-readable medium may include a non-transitory computer-readable medium (e.g., a tangible medium). Additionally, in other aspects, a computer-readable medium may include a transitory computer-readable medium (e.g., a signal). The above combinations should also be included within the scope of computer-readable media.

[0128] Accordingly, some aspects may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having (and / or encoded with) instructions executable by one or more processors to perform the operations described herein. For example, instructions for performing the operations described and shown in FIGS. 13, 17, and 18.

[0129] Furthermore, it should be understood that modules and / or other suitable means for performing the methods and techniques described herein may be downloaded and / or otherwise obtained by a user terminal and / or a base station, where applicable. For example, such a device may be coupled to a server to facilitate transfer of means for performing the methods described herein. Alternatively, the various methods described herein may be provided via a storage means (e.g., a physical storage medium such as RAM, ROM, compact disk (CD) or floppy disk, etc.) when the user terminal and / or the base station couples or provides the storage means to the device so that the various methods can be obtained. Further, any other suitable technique for providing the methods and techniques described herein to a device may be utilized.

[0130] It should be understood that the claims are not limited to the exact configurations and components shown above. Various modifications, changes, and variations may be made to the configurations, operations, and details of the methods and apparatuses described above without departing from the scope of the claims.

Description of Reference Numerals

[0131] 100 Wireless Network 102a Macrocell 102b Macrocell 102c Macrocell 102x Picocell 102y Femtocell 102z Femtocell 110 Base Station (BS) 110a BS 110b BS 110c BS, Macro BS 110r Relay Station 110x BS 110y BS 110z BS 120 UE, User Equipment, User Terminal 120r UE 120x UE 120y UE 130 Network Controller 200 Distributed Radio Access Network (RAN), Local Architecture, Architecture 202 Access Node Controller (ANC) 204 Next Generation Core Network (NG-CN) 206 5G Access Node 208 TRP, DU 210 Next Generation AN (NG-AN) 222 Tx / Rx 300 Distributed RAN 302 Centralized Core Network Unit (C-CU) 304 Centralized RAN Unit (C-RU) 306 DU 412 Data Source 420 Processor, Transmission Processor 432 Modulator, BS Modulator / Demodulator 432a~432t Modulator (MOD) 434 Antenna 434a~434t Antenna 436 MIMO Detector 438 Processor, Reception Processor 439 Data Sink 440 Controller / Processor, Processor 442 Memory 444 Scheduler 452 Antenna 452a~452r Antenna 454 Demodulator 454a~454r Demodulator (DEMOD) 456 MIMO Detector 458 Processor, Reception Processor 462 Data Source 464 Processor, Transmission Processor 466 Processor, TX MIMO Processor 480 Controller / Processor, Processor 500 Figure 505-a Option 1 505-b Option 2 510 Radio Resource Control (RRC) layer 515 Packet Data Convergence Protocol (PDCP) layer 520 Radio Link Control (RLC) layer 525 Medium Access Control (MAC) layer 530 Physical (PHY) layer 600 Figure 604 DL Data Portion 606 Common UL Portion 700 Figure 702 Control Portion 704 UL Data Portion 706 Common UL Portion 900 Operation 1000 Operation 1100 Operation 1400 Operation 1500 Operation 1600 Operation

Claims

1. A method for wireless communication by a user equipment (UE), comprising: generating, while no dedicated resources are allocated to the UE, a message having uplink data encrypted using a first key for first UE identification information and a second key derived based on information obtained from a first base station in a first cell before transitioning to the state, wherein the first key is used to encrypt uplink data to be sent to the first base station while the user equipment (UE) is in a state where no dedicated resources are allocated to the UE, and the second key is a key used between the UE and a second base station in a second cell; transmitting the message to the second base station; and further comprising receiving, from the second base station, a reconfiguration message indicating second UE identification information and information about a third key for use in encrypting uplink data transmitted in a third cell.

2. generating a reconfiguration completion message encrypted using the second key; transmitting the reconfiguration completion message to the second base station; The method according to claim 1, further comprising:

3. receiving, from the second base station, a message having downlink data; decrypting the downlink data using the second key; The method according to claim 2, further comprising:

4. The method according to claim 1, further comprising setting the UE to the state without dedicated resources and receiving, from the first base station, signaling indicating a mechanism for sending uplink data while the UE is in the state.

5. The method according to claim 1, further comprising providing at least one indication of a call type or a cause type to enable network access control of the uplink data.

6. A method for wireless communication by a serving base station, comprising: Receiving, from the UE in a state where dedicated resources are not allocated to the UE, a message having uplink data encrypted using a first key and encrypted using a second key derived by the UE based on information obtained from an anchor base station in a first cell before the UE transitions to the state, wherein the first key is used to encrypt uplink data to be sent to the anchor base station while the UE is in a state where dedicated resources are not allocated to the UE, and the second key is a key used between the UE and the serving base station; Sending a request to the anchor base station to transfer the context of the UE to the serving base station; Receiving a response to the request, the response including information regarding the second key; Decrypting the uplink data using the second key; Including; Further including the step of transmitting, to the UE, a reconstruction message indicating second UE identification information and information regarding a third key to be used by the UE to encrypt uplink data transmitted in a third cell.

7. The method according to claim 6, further comprising the step of obtaining at least one indication of call type or cause type to enable network access control of the uplink data.

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