Techniques for performing Minimization of Drive Tests (MDT)

Abstract

Certain aspects of the present disclosure generally relate to methods and apparatus for performing minimization of drive tests (MDT) operations. For example, certain aspects provide methods for wireless communications. The methods generally include receiving a measurement configuration at a radio access network (RAN) to start tracking of a user equipment (UE), determining a transition of the UE to an inactive state, and sending one or more messages in response to the determination to coordinate tracking of the UE or indicate a tracking failure.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to PCT Application No. PCT / CN2019 / 074194 filed on January 31, 2019, which has been assigned to the assignee of this application, and the entire contents of which are hereby expressly incorporated herein by reference, as if fully set forth below and for all applicable purposes. Technical Field

[0003] Aspects of the present disclosure relate to wireless communications and, more particularly, to the communication of techniques for minimization of drive tests (MDT) operations. Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies capable of supporting 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.

[0005] In some examples, a wireless multiple access communication system may include multiple base stations, each of which simultaneously supports communication for multiple communication devices, also referred to 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 (e NodeB, eNB). In other examples (e.g., in a next generation or 5G network), a wireless multiple access communication system may include multiple distributed units (DU) (e.g., edge units (EU), edge nodes (EN), radio heads (RH), smart radio heads (SRH), transmit receive points (TRP), etc.) communicating with multiple central units (CU) (e.g., central nodes (CN), access node controllers (ANC), etc.), wherein a set of one or more distributed units communicating with the central unit may define an access node (e.g., new radio base station (NR BS), new radio node-B (NRNB), network node, 5G NB, gNB, etc.). A base station or DU may communicate with a set of UEs on a downlink channel (e.g., for transmission from a base station or to a UE) and an uplink channel (e.g., for transmission from a UE to a BS or DU).

[0006] These multiple access technologies have been adopted by various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a municipal, national, regional, and even global level. An example of an emerging telecommunication standard is New Radio (NR) (e.g., 5G wireless access). NR is a collection of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband network access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and better integrating with other open standards using OFDMA with cyclic prefix (CP) on the downlink (DL) and on the uplink (UL), as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0007] However, as the demand for mobile broadband access continues to increase, there is a need for further improvements in NR technology. Preferably, these improvements should be applicable to other multi-access technologies and telecommunication standards that employ these technologies. Summary of the invention

[0008] The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed by the appended claims, some features will now be briefly discussed. After considering these discussions, and particularly after reading the section entitled "Detailed Description," those skilled in the art will understand how the features of the present disclosure provide advantages including improved communication between access points and stations in a wireless network.

[0009] Certain aspects of the present disclosure are generally directed to methods and apparatus for methods for wireless communications. The method generally includes, at a user equipment (UE), receiving a measurement configuration from a network entity for collecting measurement information to be reported to the network entity, the measurement information including beam quality information, collecting measurement information corresponding to the measurement configuration, and sending the measurement information to the network entity.

[0010] In certain aspects, the measurement information further includes information about a distribution of serving cells. In certain aspects, the measurement configuration includes a minimization of drive tests (MDT) configuration. In certain aspects, the measurement configuration configures the UE to log downlink pilot strength measurements, the method further including: logging the downlink pilot strength measurements, and sending an indication of the downlink pilot strength measurements to a network entity.

[0011] In certain aspects, collecting the measurement information includes performing radio resource measurements (RRM) via a type of reference signal indicated by the measurement configuration. The type of reference signal may include a synchronization signal or channel state information.

[0012] In certain aspects, the measurement configuration indicates whether to perform cell-level measurement or beam-level measurement when collecting measurement information. In certain aspects, the measurement configuration indicates at least one of a beam index or a beam number for collecting beam quality information. In certain aspects, the measurement configuration indicates at least one of beam numbers to be used for collecting beam quality information. In certain aspects, the measurement configuration indicates whether the measurement information includes reference signal received quality (RSRQ) or reference signal received power (RSRP).

[0013] In some aspects, the measurement configuration indicates a duration for which the measured beam quality is valid. In this case, the collection of measurement information may include measuring the beam quality, and the method further includes: discarding the measured beam quality after the duration indicated by the measurement configuration. In some aspects, the measurement configuration includes an indication of a time interval across which one or more beam quality measurements are recorded when collecting the measurement information.

[0014] Certain aspects of the present disclosure are generally directed to methods and apparatus for methods for wireless communications. The method generally includes generating a message with a measurement configuration for collecting measurement information to be reported to a network entity, the measurement information including beam quality information, sending the measurement configuration to a user equipment (UE), and receiving another message with measurement information corresponding to the measurement configuration.

[0015] In certain aspects, the measurement information further comprises: information about a distribution of serving cells. In certain aspects, the measurement configuration comprises a minimization of drive tests (MDT) configuration. In certain aspects, the measurement configuration configures the UE to log downlink pilot strength measurements, and wherein the another message comprises an indication of the downlink pilot strength measurements.

[0016] In certain aspects, collecting the measurement information includes performing radio resource measurements (RRM) via a type of reference signal indicated by the measurement configuration. In certain aspects, the type of reference signal may include a synchronization signal or channel state information.

[0017] In certain aspects, the measurement configuration indicates whether to perform cell-level measurements or beam-level measurements when collecting measurement information. In certain aspects, the measurement configuration indicates at least one of a beam index or a beam number to be used for collecting beam quality information. In certain aspects, the measurement configuration indicates at least one of a beam number to be used for collecting beam quality information. In certain aspects, the measurement configuration indicates whether the measurement information includes reference signal received quality (RSRQ) or reference signal received power (RSRP). In certain aspects, the measurement configuration indicates a duration for which the beam quality measured is valid. In certain aspects, the measurement configuration includes an indication of a time interval across which one or more beam quality measurements are recorded when collecting measurement information.

[0018] Certain aspects of the present disclosure are generally directed to methods and apparatus for wireless communications. The methods generally include determining, at a user equipment (UE), location information associated with an out-of-coverage area, the location information being determined based on a location of the UE and data from one or more sensors, and reporting the location information to a network entity.

[0019] Certain aspects of the present disclosure are generally directed to methods and apparatus for methods for wireless communications. The method generally includes, at a first radio access network (RAN), receiving a measurement configuration to initiate tracking of a user equipment (UE), determining a transition of the UE to an inactive state, and, in response to the determination, sending one or more messages to coordinate the tracking of the UE or indicate a failure of the tracking.

[0020] Certain aspects of the present disclosure are generally directed to methods and apparatus for methods for wireless communications. The method generally includes detecting whether a user equipment (UE) is in an inactive state, determining a measurement configuration to start tracking of the UE, the measurement configuration being determined based on whether the UE is in the inactive state, generating a message including the measurement configuration, and sending a message to a radio access network (RAN) to coordinate the tracking.

[0021] Certain aspects of the present disclosure generally relate to methods and apparatus for methods for wireless communication. The method generally includes receiving a message with a measurement configuration to start tracking of a UE, the UE being in an inactive state, generating another message with the measurement configuration to start the tracking, and sending the another message to the UE.

[0022] Aspects generally include methods, apparatus, systems, computer program products, and processing systems as generally described herein with reference to and as illustrated by the accompanying figures.

[0023] To accomplish the foregoing and related ends, one or more aspects include the features fully described below and the features particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are merely indicative of some of the various ways in which the principles of the various aspects may be employed, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order that the manner in which the above-mentioned features of the present disclosure may be understood in detail, a more specific description of the content briefly summarized above may be made with reference to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only certain typical aspects of the present disclosure and are therefore not to be considered as limiting the scope thereof, as the specification may admit of other equally effective aspects.

[0025] Figure 1 is a block diagram conceptually illustrating an example telecommunications system in accordance with certain aspects of the present disclosure.

[0026] Figure 2 is a block diagram illustrating an example logical architecture of a distributed radio access network (RAN) in accordance with certain aspects of the present disclosure.

[0027] Figure 3 is a schematic diagram illustrating an example physical architecture of a distributed RAN in accordance with certain aspects of the present disclosure.

[0028] Figure 4 is a block diagram conceptually illustrating designs of example base stations (BSs) and user equipment (UEs) in accordance with certain aspects of the present disclosure.

[0029] Figure 5 is a diagram illustrating an example for implementing a communication protocol stack in accordance with certain aspects of the present disclosure.

[0030] Figure 6 An example of a frame format for a New Radio (NR) system is shown in accordance with certain aspects of the present disclosure.

[0031] Figure 7 Showing different operating states of a UE for NR.

[0032] Figure 8 is a flow diagram illustrating example operations for wireless communications in accordance with certain aspects of the present disclosure.

[0033] Fig. 9 is a flow diagram illustrating example operations for wireless communications in accordance with certain aspects of the present disclosure.

[0034] Fig.10 is a flow diagram illustrating example operations for wireless communications in accordance with certain aspects of the present disclosure.

[0035] Fig.11 UE tracking relative position of an area outside of coverage area in accordance with certain aspects of the present disclosure.

[0036] Fig.12 is a flow diagram illustrating example operations for wireless communications in accordance with certain aspects of the present disclosure.

[0037] Fig.13 is a flow diagram illustrating example operations for wireless communications in accordance with certain aspects of the present disclosure.

[0038] Fig.14 is a flow diagram illustrating example operations for wireless communications in accordance with certain aspects of the present disclosure.

[0039] Fig.15 Example operations for coordinating logged minimization of drive tests (MDT) traces for inactive state UEs with trace failure indications are illustrated in accordance with certain aspects of the present disclosure.

[0040] Fig.16 Example operations for coordinating logged MDT tracking for inactive state UEs are illustrated in accordance with certain aspects of the present disclosure.

[0041] Fig.17 Example operations for deferring logged MDT tracing in accordance with certain aspects of the present disclosure are illustrated.

[0042] Figure 18-23 A communication device according to aspects of the present disclosure is shown that may include various components configured to perform operations for the techniques disclosed herein.

[0043] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation. DETAILED DESCRIPTION

[0044] Various aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for performing minimized drive tests (MDT). For example, certain aspects provide MDT operations that take into account new types of coverage introduced by next-generation specific features. For example, new radio (NR) supports intra-cell beam level mobility (e.g., beam switching without RRC involvement) and introduces new types of beam coverage. Certain aspects of the present disclosure also provide MDT-specific logged measurement configurations with beam coverage, and new types of location information acquisition operations for MDT measurements, which may be applicable to environments that do not support RF fingerprints for GNSS or neighboring cells. Certain aspects also provide techniques for performing immediate MDT and logged MDT processing for UEs in an RRC inactive state.

[0045] The following description provides examples and is not a limitation of the scope, applicability or examples set forth in the claims. Changes may be made to the functions and arrangements of the elements discussed without departing from the scope of the present disclosure. Various processes or components may be omitted, replaced or added to each example as appropriate. For example, the method described may be performed in an order different from the order described, and various steps may be added, omitted or combined. In addition, the features described with respect to some examples may be combined in other examples. For example, a device may be implemented or a method may be implemented using any number of aspects set forth herein. In addition, the scope of the present disclosure is intended to cover such devices or methods implemented using other structures, functions, or structures and functions that are supplementary to or different from the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements in the claims. The word "exemplary" used herein means "used as an example, instance or illustration". Any aspect described as "exemplary" herein is not necessarily interpreted as being preferred over or having advantages over other aspects.

[0046] The technology described herein can 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 can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variations of CDMA. Cdma2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network can implement radio technologies such as Global System for Mobile Communications (GSM). An OFDMA network can implement radio 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 Universal Mobile Telecommunications System (UMTS). NR is an emerging wireless communication technology in development in conjunction with the 5G Technology Forum (5GTF). 3GPP Long Term Evolution (LTE) and Improved LTE (LTE-A) are releases of UMTS using E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). Cdma2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The technology described herein can be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, although various aspects may be described herein using terms commonly associated with 3G, 4G, 5G, or NR wireless technologies, various aspects of the present disclosure may be applied in other communication systems based on generations.

[0047] Example Wireless Communication System

[0048] Figure 1 An example wireless communication network 100 is shown in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be a New Radio (NR) or 5G network.

[0049] like Figure 1As shown, the wireless communication network 100 may include multiple base stations (BS) 110 and other network entities. A BS may be a station that communicates with a user equipment (UE). Each BS 110 may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a Node B (NB) and / or a NB subsystem serving the coverage area, depending on the context in which the term is used. In the NR system, the term "cell" and the next generation Node B (gNB or gNodeB), NR BS, 5G NB, access point (AP) or transmit receive point (TRP) may be interchangeable. In some examples, the cell may not necessarily be stationary, and the geographical area of ​​the cell may move according to the location of the mobile BS. In some examples, the base stations may be interconnected to each other and / or to one or more other base stations or network nodes (not shown) in the wireless communication network 100 through various types of backhaul interfaces (such as direct physical connections, wireless connections, virtual networks, etc.) using any suitable transmission network.

[0050] In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies. RAT may also be referred to as radio technology, air interface, etc. Frequency may also be referred to as carrier, subcarrier, frequency channel, tone, subband, etc. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

[0051] A BS may provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell may cover a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs for users in a residence, etc.). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1In the example shown, BS 110a, BS 110b, and BS 110c may be macro BSs for macro cell 102a, macro cell 102b, and macro cell 102c, respectively. BS 110x may be a pico BS for pico cell 102x. BS 110y and BS 110z may be femto BSs for femto cell 102y and femto cell 102z, respectively. A BS may support one or more (e.g., three) cells.

[0052] The wireless communication network 100 may also include a relay station. 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). A relay station may also be a UE that relays transmissions for other UEs. Figure 1 In the illustrated example, a relay station 110r may communicate with a BS 110a and a UE 120r to facilitate communication between the BS 110a and the UE 120r. A relay station may also be referred to as a relay BS, a relay, or the like.

[0053] The wireless communication network 100 may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, repeaters, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless communication network 100. For example, a macro BS may have a high transmit power level (e.g., 20 watts), while a pico BS, a femto BS, and a repeater may have a low transmit power level (e.g., 1 watt).

[0054] The wireless communication network 100 may support synchronous operation or asynchronous operation. For synchronous operation, the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timing, and transmissions from different BSs may be misaligned in time. The techniques described herein may be used for both synchronous and asynchronous operation.

[0055] A network controller 130 may be coupled to a set of BSs and provide coordination and control for these BSs. The network controller 130 may communicate with the BSs 110 via a backhaul. The BSs 110 may also communicate with each other via a wireless backhaul or a wired backhaul (eg, directly or indirectly).

[0056] UE 120 (e.g., UE 120x, UE 120y, etc.) may be dispersed throughout the wireless communication network 100, and each UE may be stationary or mobile. UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a customer premises equipment (CPE), a cellular phone, a smart phone, 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 computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a home appliance, a medical device or medical equipment, a biometric sensor / device, a wearable device (such as a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring, a smart bracelet, etc.)), an entertainment device (e.g., a music device, a video device, a satellite radio unit, etc.), a vehicle component or sensor, a smart meter / sensor, industrial manufacturing 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 considered as machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC UEs and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which may communicate with a BS, another device (e.g., a remote device), or some other entity. For example, a wireless node may provide connectivity to or to a network (e.g., a wide area network such as the Internet or a cellular network) via a wired communication link or a wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

[0057] 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 multiple (K) orthogonal subcarriers, which are also collectively referred to as tones, frequency bins, etc. Each subcarrier can be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can be dependent on the system bandwidth. For example, the spacing of the subcarriers can be 15kHz, and the minimum resource allocation (called a "resource block" (RB)) can be 12 subcarriers (or 180kHz). Thus, for a system bandwidth of 1.25 megahertz (MHz), 2.5 MHz, 5 MHz, 10 MHz, or 20 MHz, the nominal Fast Fourier Transform (FFT) size may be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth may also be divided into subbands. For example, a subband may cover 1.8 MHz (i.e., 6 resource blocks), and for a system bandwidth of 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, or 20 MHz, there may be 1, 2, 4, 8, or 16 subbands, respectively.

[0058] Although aspects of the examples described herein may be associated with LTE technology, aspects of the present disclosure may be applicable to other wireless communication systems, such as NR. NR may utilize OFDM with CP on uplink and downlink, and include support for half-duplex operation using TDD. Beamforming may be supported, and the beam direction may be dynamically configured. MIMO transmission with precoding may also be supported. With up to 8 streams and multi-layer DL transmission of up to 2 streams per UE, the MIMO configuration in DL may support up to 8 transmit antennas. Multi-layer transmission with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells.

[0059] In some examples, access to the air interface can be scheduled. The entity that performs scheduling (e.g., BS) allocates resources for communication between some or all devices and equipment within its service area or cell. The entity that performs scheduling can be responsible for scheduling, allocating, reconfiguring and releasing resources for one or more subordinate entities. That is, for scheduled communications, subordinate entities utilize resources allocated by the entity that performs scheduling. The base station is not the only entity that can act as an entity that performs scheduling. In some examples, UE can act as an entity that performs scheduling, and can schedule resources for one or more subordinate entities (e.g., one or more other UEs), and other UEs can utilize resources for wireless communication scheduled by UE. In some examples, UE can act as an entity that performs scheduling in a peer-to-peer (P2P) network and / or in a mesh network. In the mesh network example, in addition to communicating with the entity that performs scheduling, UEs can communicate with each other directly.

[0060] exist Figure 1 In FIG. 1 , a solid line with double arrows indicates a desired transmission between a UE and a serving BS, which is a BS designated to serve the UE on a downlink and / or uplink. A thin dashed line with double arrows indicates an interfering transmission between the UE and the BS.

[0061] Figure 2 Shows that it can be Figure 1 An example logical architecture of a distributed radio access network (RAN) 200 implemented in the wireless communication network 100 is shown. The 5G access node 206 may include an access node controller (ANC) 202. The ANC 202 may be a central unit (CU) of the distributed RAN 200. The backhaul interface to the next generation core network (NG-CN) 204 may terminate at the ANC 202. The backhaul interface to the neighboring next generation access node (NG-AN) 210 may terminate at the ANC 202. The ANC 202 may include one or more TRPs 208 (e.g., cells, BSs, gNBs, etc.).

[0062] The TRP 208 may be a distributed unit (DU). The TRP 208 may be connected to a single ANC (e.g., ANC 202) or more than one ANC (not shown). For example, for RAN sharing, Radio as a Service (RaaS), and service-specific AND deployments, the TRP 208 may be connected to more than one ANC. The TRPs 208 may each include one or more antenna ports. The TRPs 208 may be configured to serve traffic to the UE individually (e.g., dynamically selected) or jointly (e.g., joint transmission).

[0063] The logical architecture of the distributed RAN 200 may support fronthaul solutions across different deployment types. For example, the logical architecture may be based on transmit network capabilities (eg, bandwidth, latency, and / or jitter).

[0064] The logical architecture of the distributed RAN 200 may share features and / or components with LTE. For example, the next generation access node (NG-AN) 210 may support dual connectivity with NR and may share a common fronthaul for LTE and NR.

[0065] The logical architecture of the distributed RAN 200 may enable collaboration between and among TRPs 208, within and / or across TRPs, for example, via the ANC 202. An inter-TRP interface may not be used.

[0066] Logical functions may be dynamically distributed in the logical architecture of the distributed RAN 200. Figure 5 Described in more detail, 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 placed at the DU (e.g., TRP 208) or the CU (e.g., ANC 202).

[0067] Figure 3 An example physical architecture of a distributed RAN 300 according to aspects of the present disclosure is shown. A centralized core network unit (C-CU) 302 may host core network functions. The C-CU 302 may be centrally deployed. C-CU 302 functions may be offloaded (e.g., to an improved wireless service (AWS)) in an attempt to handle peak capacity.

[0068] A centralized RAN unit (C-RU) 304 may host one or more ANC functions. Alternatively, the C-RU 304 may host core network functions locally. The C-RU 304 may have a distributed deployment. The C-RU 304 may be close to the network edge.

[0069] The 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 the network with radio frequency (RF) capabilities.

[0070] Figure 4 BS 110 and UE 120 (eg Figure 14, 440, 450, 460, 470, 480, 490, 500, 510, 520, 530, 540, 550, 560, 570, 580, 590, 600, 610, 620, 630, 640, 650, 660, 670, 680, 690, 700, 710, 720, 730, 740, 750, 760, 770, 780, 790, 800, 810, 820, 830, 840, 850, 860, 870, 880, 890, 900, 910, 920, 930, 940, 950, 960, 970, 980, 990, 1000, 1010, 1020, 1030, 1040, 1050, 1060, 1070, 1080, 1090, 1100, 1110, 1120, 1130, 1140, 1150, 1160, 1170, 1180, 1190, 1201, 1210

[0071] At BS 110, a transmit processor 420 may receive data from a data source 412 and control information from a controller / processor 440. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), etc. The data may be for a physical downlink shared channel (PDSCH), etc. The processor 420 may process (e.g., encode and symbol map) the data and the control information to obtain data symbols and control symbols, respectively. The processor 420 may also generate reference symbols, such as for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a cell-specific reference signal (CRS). The transmit (TX) multiple-input multiple-output (MIMO) processor 430 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, and / or reference symbols (if applicable), and may provide output symbol streams to modulators (MODs) 432a to 432t. Each modulator 432 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 432a through 432t may be transmitted via antennas 434a through 434t, respectively.

[0072] At the UE 120, antennas 452a to 452r can receive downlink signals from the base station 110 and can provide received signals to demodulators (DEMODs) in transceivers 454a to 454r, respectively. Each demodulator 454 can condition (e.g., filter, amplify, down-convert, and digitize) the respective received signals to obtain input samples. Each demodulator 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 detected symbols. The receive processor 458 can process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120 to the data sink 460, and provide decoded control information to the controller / processor 480.

[0073] On the uplink, at the UE 120, the transmit processor 464 may receive and process data from a data source 462 (e.g., for a physical uplink shared channel (PUSCH)) and control information from a controller / processor 480 (e.g., for a physical uplink control channel (PUCCH)). The transmit processor 464 may also generate reference symbols for reference signals (e.g., for a sounding reference signal (SRS)). The symbols from the transmit processor 464 may be precoded by a TX MIMO processor 466 (if applicable), further processed by demodulators 454a through 454r in the transceiver (e.g., for SC-FDM, etc.), and transmitted to the base station 110. At the BS 110, the uplink signals from the UE 120 may be received by the antenna 434, processed by the demodulator 432, detected by the MIMO detector 436 (if applicable), and further processed by the receive processor 438 to obtain decoded data and control information sent by the UE 120. The receive processor 438 may provide decoded data to a data sink 439 and decoded control information to a controller / processor 440 .

[0074] Controller / processor 440 and controller / processor 480 may direct the operation at BS 110 and UE 120, respectively. Processor 440 and / or other processors and modules at BS 110 may perform or direct the execution of processes for the techniques described herein. Memory 442 and memory 482 may store data and program codes for BS 110 and UE 120, respectively. Scheduler 444 may schedule UEs for data transmission on the downlink and / or uplink.

[0075] Figure 5A schematic diagram 500 illustrating an example for implementing a communication protocol stack according to various aspects of the present disclosure is illustrated. The communication protocol stack shown may be implemented by a device operating in a wireless communication system such as a 5G system (e.g., a system supporting uplink-based mobility). Schematic diagram 500 illustrates a communication protocol stack including an RRC layer 510, a PDCP layer 515, an RLC layer 520, a MAC layer 525, and a PHY layer 530. In various examples, the layers of the protocol stack may be implemented as separate software modules, as part of a processor or ASIC, as part of a non-collocated device connected by a communication link, or various combinations thereof. For example, collocated and non-collocated implementations may be used in a protocol stack for a network access device (e.g., AN, CU, and / or DU) or a UE.

[0076] The first option 505-a illustrates a split implementation of the protocol stack, in which the implementation of the protocol stack is performed on a centralized network access device (e.g., Figure 2 ANC 202 in the system) and distributed network access equipment (e.g., Figure 2 In the first option 505-a, the RRC layer 510 and the PDCP layer 515 may be implemented by a central 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 non-collocated. The first option 505-a may be useful in macro cell, micro cell, or pico cell deployments.

[0077] The second option 505-b shows a unified implementation of the protocol stack, in which the protocol stack is implemented in a single network access device. In the second option, the RRC layer 510, the PDCP layer 515, the RLC layer 520, the MAC layer 525, and the PHY layer 530 can all be implemented by the AN. The second option 505-b can be useful in, for example, a femtocell deployment.

[0078] Regardless of whether the network access device implements part of the protocol stack or all of the protocol stack, the UE can implement the entire protocol stack as shown in 505-c (e.g., RRC layer 510, PDCP layer 515, RLC layer 520, MAC layer 525 and PHY layer 530).

[0079] In LTE, the basic transmission time interval (TTI) or packet duration is a 1ms subframe. In NR, the subframe is still 1ms, but the basic TTI is called a time slot. A subframe contains a variable number of time slots (e.g., 1, 2, 4, 8, 16, ... time slots) depending on the subcarrier spacing. An NR RB is 12 consecutive frequency subcarriers. NR can support a basic subcarrier spacing of 15KHz, and other subcarrier spacings can be defined relative to the basic subcarrier spacing (e.g., 30kHz, 60kHz, 120kHz, 240kHz, etc.). Symbol and time slot lengths scale with the subcarrier spacing. The CP length also depends on the subcarrier spacing.

[0080] Figure 6 600 for NR. The transmission timeline for each of the downlink and uplink may be divided into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10 ms), and each radio frame may be divided into 10 subframes, each of which is 1 ms and has an index of 0 to 9. Each subframe may include a variable number of slots depending on the subcarrier spacing. Each slot may include a variable number of symbol periods (e.g., 7 or 14 symbols) depending on the subcarrier spacing. An index may be assigned to the symbol period in each slot. A microslot (which may be referred to as a subslot structure) refers to a transmission time interval having a duration less than a slot (e.g., 2, 3, or 4 symbols).

[0081] Each symbol in a slot may indicate a link direction (e.g., DL, UL, or flexible link direction) for data transmission, and the link direction for each subframe may be dynamically changed. The link direction may be based on the slot format. Each slot may include DL / UL data and DL / UL control information.

[0082] In NR, a synchronization signal (SS) block is transmitted. The SS block includes PSS, SSS, and two-symbol PBCH. The SS block can be in a fixed time slot position (e.g., Figure 6Symbols 0-3 shown in the figure). PSS and SSS can be used by UE for cell search and acquisition. PSS can provide half-frame timing, and SS can provide CP length and frame timing. PSS and SSS can provide cell identity. PBCH carries some basic system information, such as downlink system bandwidth, timing information within the radio frame, SS burst set periodicity, system frame number, etc. SS blocks can be organized into SS bursts to support beam scanning. Further system information such as remaining minimum system information (RMSI), system information block (SIB), other system information (OSI) can be sent on the physical downlink shared channel (PDSCH) in certain subframes. SS blocks can be, for example, sent up to 64 times using up to 64 different beam directions for mmW. Up to 64 transmissions of SS blocks are called SS burst sets. SS blocks in an SS burst set are sent in the same frequency region, while SS blocks in different SS burst sets may be sent at different frequency locations.

[0083] In some cases, two or more subordinate entities (e.g., UEs) may communicate with each other using sidelink signals. Real-life applications of such sidelink communications may include public safety, neighbor services, UE-to-network relay, vehicle-to-vehicle (V2V) communications, Internet of Everything (IoE) communications, IoT communications, mission-critical networks, and / or various other suitable applications. Generally, a sidelink signal may refer to a signal transmitted from one subordinate entity (e.g., UE1) to another subordinate entity (e.g., UE2) without relaying the transmission through a scheduling entity (e.g., UE or BS), even though the scheduling entity may be used for scheduling and / or control purposes. In some examples, the sidelink signal may be transmitted using a licensed spectrum (unlike a wireless local area network, which typically uses an unlicensed spectrum).

[0084] The UE may operate in various radio resource configurations, including configurations associated with sending pilots using a dedicated set of resources (e.g., a radio resource control (RRC) dedicated state, etc.), or configurations associated with sending pilots using a common set of resources (e.g., an RRC common state, etc.). When operating in the RRC dedicated state, the UE may select a dedicated set of resources for sending pilot signals to the network. When operating in the RRC common state, the UE may select a common set of resources for sending pilot signals to the network. In either case, the pilot signal sent by the UE may be received by one or more network access devices (such as an AN or DU or a portion thereof). Each receiving network access device may be configured to receive and measure pilot signals sent on the common set of resources, and also receive and measure pilot signals sent on the dedicated set of resources allocated to the UE for which the network access device is a member of a set of network access devices monitoring the UE. The receiving network access device or one or more of the CUs to which the receiving network access device sends measurements of the pilot signal can use the measurements to identify a serving cell for the UE, or initiate a change to a serving cell for one or more of the UEs.

[0085] Example Radio Resource Control (RRC) States

[0086] Figure 7 Different operational states 700 of a UE for NR are shown. As shown, an RRC inactive state 704 is included, allowing a UE in an RRC connected state 702 to transition to an RRC inactive state 704 or an RRC idle state 706. In the RRC inactive state 704, both the RAN and the UE save the UE context even after the UE is released from the network. Therefore, as long as the UE is in the same RAN Notification Area (RNA), the UE and the RAN can apply the stored UE context, thereby allowing the UE to return to the RRC connected state 702 with a smaller number of signaling operations, resulting in a faster transition to the RRC connected state 702. The operator can configure an appropriate RNA.

[0087] The RRC inactive state is a state in which the UE access stratum (AS) context is maintained at the UE and the anchoring next generation (NG) RAN. In the RRC inactive state, the core network control plane (N2) / user plane (N3) interface is maintained for the access and mobility management function (AMF) and the user plane function (UPF). AMF is a network function that supports termination of non-access stratum (NAS) signaling, NAS encryption and integrity protection, registration management, connection management, mobility management, access authentication and authorization, and security context management. UPF is a network function that supports packet routing and forwarding, packet inspection, quality of service (QoS) processing, acts as an external protocol data unit (PDU) session point for interconnection with the data network, and is an anchor point for intra-radio access technology (RAT) mobility and inter-radio access technology (RAT) mobility. In addition, the UE can follow idle mode mobility behavior in the RRC inactive state.

[0088] Example Techniques for Performing Minimization of Drive Tests (MDT)

[0089] Minimization of Drive Tests (MDT) refers to a feature used to allow operators to improve network planning. For example, MDT operations can be used for user equipment (UE) to collect measurements and report the measurements to the network. There are two types of MDT operations, which are called immediate MDT and logged MDT. For immediate MDT, measurements are performed by UEs in a radio resource control (RRC) connected state. The information collected during the connected state is reported to the network when available. For logged MDT, measurements are performed and logged by UEs in the "normal stay" state and the "any cell selection" state of idle mode. The UE can report the collected information for logged MDT to the network at an appropriate later point in time.

[0090] In Long Term Evolution (LTE) MDT operation, the RRC inactive state is not implemented. In addition, there may be no MDT measurements for beam coverage and Radio Access Network (RAN) Notification Area (RNA) coverage improvement. LTE may not define MDT measurements for situations where there is no Global Navigation Satellite System (GNSS) or neighboring cell radio frequency (RF) fingerprint. RF fingerprinting is the process of identifying the device for which a radio transmission is issued by looking at the properties of the transmission, including the specific radio frequency. Each signal originator may have a unique RF fingerprint based on the location and configuration of the signal it transmits.

[0091] Certain aspects of the present disclosure are directed to: MDT operations that take into account new types of coverage introduced by next-generation specific features. For example, New Radio (NR) supports intra-cell beam level mobility (e.g., beam switching without RRC involvement) and introduces new types of beam coverage. Certain aspects of the present disclosure also provide: MDT specific logged measurement configurations with beam coverage, and new types of location information acquisition operations for MDT measurements, which may be applicable to environments that do not support RF fingerprints for GNSS or neighboring cells. Certain aspects also provide techniques for performing immediate MDT and logged MDT processing for UEs in an RRC inactive state.

[0092] Figure 8 8 is a flow diagram illustrating example operations 800 for wireless communications in accordance with certain aspects of the present disclosure. Operations 800 may be performed by a UE, such as UE 120.

[0093] Operations 800 begin at block 802 by receiving a measurement configuration from a network entity for collecting measurement information to be reported to the network entity. In certain aspects, the measurement information may include beam quality information and / or information about distribution of serving cells. At block 804, the UE collects measurement information corresponding to the measurement configuration, and at block 806, sends the measurement information to the network entity.

[0094] Fig. 9 9 is a flow diagram illustrating example operations 900 for wireless communications in accordance with certain aspects of the present disclosure. Operations 900 may be performed by a network entity such as base station 110 or a radio access network.

[0095] Operation 900 may be implemented as a processor on one or more processors (e.g., Figure 4 Further, the communication may be performed, for example, via one or more antennas (e.g., Figure 4 The antenna 434 of the BS implements the transmission and reception of signals by the BS in operation 900. In some aspects, the transmission and / or reception of signals by the BS may be implemented by obtaining and / or outputting signals via a bus interface of one or more processors (e.g., the controller / processor 440).

[0096] Operations 900 begin at block 902, where a base station generates a message with a measurement configuration for collecting measurement information to be reported to a network entity. In certain aspects, the measurement information may include beam quality information and / or information about distribution of serving cells. At block 904, the base station sends the measurement configuration to a UE (e.g., UE 120), and at block 906, receives another message with measurement information corresponding to the measurement configuration.

[0097] In other words, MDT-specific idle mode measurements may be used to collect information about beam quality and distribution of serving cells. In some cases, the operations described herein may also involve: configuring the UE to log downlink pilot strength measurements. In some cases, the measurement configuration may specify which type of reference signal (e.g., synchronization signal (SS) or channel state information reference signal (CSI-RS)) to use when performing radio resource measurements (RRM).

[0098] In certain aspects, the measurement configuration may also indicate to the UE whether to perform cell-level measurements (e.g., reusing idle mode measurements) or beam-level measurements using MDT-specific parameters. For beam-level measurements, the UE may be indicated the L3 beam measurement information to be used, such as the beam number or beam index, or both the beam index and the number of beams.

[0099] The threshold for triggering beam reporting and the beam number for L3 beam reporting may also be indicated to the UE via the measurement configuration. The measurement configuration may also indicate whether reference signal received power (RSRP) or reference signal received quality (RSRQ) is to be used for measurement.

[0100] The measurement configuration may also indicate to the UE a beam validity duration, which indicates how long the measured beam quality information remains valid. For example, the UE may store the measured beam quality, and when a beam validity timer (e.g., which corresponds to the indicated beam validity duration) expires, the measurement result may be considered invalid and thus discarded by the UE. The time interval for recording beam quality measurements may also be indicated to the UE, which time interval may be adjusted based on the communication environment.

[0101] In legacy MDT, location information is obtained via satellites (e.g., GNSS or BeiDou Navigation Satellite System (BDS)). The report may include an indication of the latitude and longitude corresponding to the location of the UE. Location information may also be obtained by the UE (e.g., via RF fingerprints as described herein) using neighboring cell measurements to determine the UE location. However, cell coverage and GNSS may not always be available. Legacy recorded MDT works when the UE is normally camped on a cell (e.g., in a "normal camped" state) and in a state where the UE attempts to find any acceptable cell (e.g., in an "any cell selection" state). This also means that location information is available via GNSS or neighboring cell RF fingerprints. When the UE enters a coverage area where no location information is available (e.g., an out of coverage (OOC) cell), the UE may not be able to report the location of the coverage blind area. Certain aspects of the present disclosure are generally directed to techniques for performing MDT without GNSS or neighboring cell RF fingerprints.

[0102] Fig.10 10 is a flow diagram illustrating example operations 1000 for wireless communications in accordance with certain aspects of the present disclosure. Operations 1000 may be performed by a UE, such as UE 120.

[0103] Operation 1000 may be implemented as a processor on one or more processors (e.g., Figure 4 Further, the communication may be performed, for example, via one or more antennas (e.g., Figure 4 The antenna 452 of the controller 450 implements the transmission and reception of signals by the UE in operation 1000. In some aspects, the signal can be obtained and / or output via a bus interface of one or more processors (e.g., the controller / processor 480) to implement the transmission and / or reception of signals by the UE.

[0104] Operations 1000 begin at block 1002, where the UE determines location information associated with an out-of-coverage area (e.g., an area without available satellite positioning system or cell coverage). In certain aspects, the location information may be determined based on the location of the UE (e.g., a location with available satellite positioning system or cell coverage) and data from one or more sensors. At block 1004, the UE reports the location information to a network entity.

[0105] In other words, the direction, distance, altitude, and speed may be determined by the UE using information from the UE's internal sensors (such as a gyroscope and a compass). For example, the location information may be determined by calculating a relative position associated with an area outside the coverage area relative to the UE's position via data from one or more sensors. Using sensor-based location information acquisition, after the UE enters a normal cell, the UE may calculate its relative movement trajectory relative to the normal cell, and use the sensor-based location information (e.g., distance, direction, altitude, speed) to report the coverage blind area, such as relative to the normal cell. Fig.11 Described in more detail.

[0106] Fig.11 UE 120 is shown tracking relative position of an area outside of coverage area in accordance with certain aspects of the present disclosure. As shown, the UE may be located at location A, which is in an OOC cell 1102 without any available GNSS or neighboring cell RF fingerprints. Therefore, the UE can trigger the acquisition of sensor-based location information as described herein. For example, UE 120 can record the movement direction, speed, distance, and corresponding timestamp until the UE is located at location B in cell 1104, where the UE is in a normal resident state. The UE can then calculate the relative position of location A relative to location B and record the measurement results for reporting to the network.

[0107] As in this article Figure 7 As described, NR introduces an RRC inactive state between a connected state and an idle state. Certain aspects of the present disclosure are directed to techniques for performing immediate MDT and logged MDT processing for a UE in an RRC inactive state.

[0108] The access and mobility management function (AMF) network entity may or may not be subscribed to the RAN to request an RRC inactive state transition report when entering the RRC inactive state from the RRC connected state or leaving the RRC inactive state to the RRC connected state. Immediate MDT is applicable to RRC connected mode UEs and is not applicable to RRC inactive mode UEs because Immediate MDT is used to measure ongoing services (e.g., Quality of Service (QoS) verification, data volume measurement, scheduled IP throughput, interference power received by the RAN). Certain aspects of the present disclosure are directed to a UE state-aware AMF for triggering an appropriate MDT protocol.

[0109] Fig.12 12 is a flow diagram illustrating example operations 1200 for wireless communications in accordance with certain aspects of the present disclosure. Operations 1200 may be performed by an AMF.

[0110] Operations 1200 begin at block 1202, where the AMF detects whether the UE is in an inactive state. At block 1204, the AMF determines a measurement configuration to start tracking of the UE, the measurement configuration being determined based on whether the UE is in an inactive state, and at block 1206, a message including the measurement configuration is generated. At block 1208, the AMF sends a message to the radio access network to coordinate tracking. In other words, if the AMF is aware that the UE transitions to an RRC inactive state, the AMF may be configured to appropriately trigger the correct type of MDT measurement. For example, the AMF may not trigger immediate MDT for a UE in RRC inactive mode.

[0111] Certain aspects of the present disclosure are directed to an AMF that may not be aware of a UE transitioning to an RRC inactive state. In this case, the RAN may be responsible for handling MDT (e.g., immediate MDT) that may be triggered by the AMF for a UE in RRC inactive mode.

[0112] Fig.13 is a flow diagram illustrating example operations 1300 for wireless communications in accordance with certain aspects of the present disclosure. Operations 1300 may be performed by a network entity such as a RAN (eg, an anchor RAN).

[0113] Operations 1300 begin at block 1302 by the RAN receiving a measurement configuration to start tracking of a user equipment (UE). At block 1304, the RAN determines that the UE transitions to an inactive state, and at block 1306, in response to the determination, sends one or more messages to coordinate tracking of the UE or indicate a tracking failure. For example, if an immediate MDT is triggered for an RRC inactive mode UE, a tracking failure indication may be sent from the NG-RAN to the AMF.

[0114] In certain aspects of the present disclosure, the RAN may handle a logged MDT triggered by the AMF for an RRC inactive state UE via the UE's new serving RAN. For example, the logged MDT may be immediately configured using RAN paging. For example, the anchor RAN may send a RAN paging message to the UE's new serving RAN to trigger the UE to enter an RRC connected state. In another aspect, as described in more detail herein, the logged MDT may be postponed until the UE enters a connected state via an RRC resume request to the new serving RAN.

[0115] Fig.14 is a flow diagram illustrating example operations 1400 for wireless communications in accordance with certain aspects of the present disclosure. Operations 1400 may be performed by a RAN (eg, a serving RAN for a UE).

[0116] Operations 1400 begin at block 1402, where the RAN receives a message with a measurement configuration to start tracking of a UE, where the UE is in an inactive state. At block 1404, the RAN may generate another message with the measurement configuration to start tracking, and at block 1406, send the other message to the UE.

[0117] In certain aspects, the message with the measurement configuration may be a trace start message from an AMF network entity. In this case, the new serving RAN may send a path switch request to the AMF before receiving the trace start message. In another aspect, operation 1400 may include: the RAN sending a UE context request message to another RAN (e.g., an anchor RAN), wherein the message with the measurement configuration is a UE context response message received after sending the UE context request message. In this case, operation 1400 also includes: after receiving the UE context response message, sending a radio resource control (RRC) recovery message to the UE, as described in more detail herein.

[0118] In certain aspects, an indication may be sent to the AMF that the logged MDT trace has failed, and the trace for the logged MDT may be reattempted in the new serving NG-RAN after context retrieval, as with respect to Fig.15 Described in more detail.

[0119] Fig.15 Example operations 1500 are shown for coordinating logged MDT traces for an inactive state UE with a trace failure indication in accordance with certain aspects of the present disclosure. At block 1510, the UE may enter an RRC inactive state. As shown, after the anchor RAN 1506 receives a trace start message 1512 from the AMF, the anchor RAN 1506 determines that the UE is in an inactive state and sends a trace failure indication 1514 to the AMF entity 1508 indicating that the trace has failed (because the UE 1502 is in an inactive state). The anchor RAN 1506 then sends a RAN paging message 1516 to the new serving RAN 1504 of the UE 1502, triggering the RRC connection protocol for the UE 1502 to enter the RRC connected state. For example, the new serving RAN 1504 may send a paging message 1518 to the UE 1502 and receive an RRC resume request 1520 from the UE 1502.

[0120] The new serving RAN 1504 may then retrieve the UE context from the anchor RAN 1506 by sending a Retrieve UE Context Request message 1522 to the anchor RAN 1506, and receive a UE Context Response 1524 with the context of the UE 1502. The new serving RAN 1504 may then send an RRC Resume message 1526 to the UE 1502, and send a Path Switch Request 1528 to the AMF 1508. In response to the new serving RAN 1504 sending a Logged Measurement Configuration message 1532 to the UE 1502 (which configures the UE to perform logged MDT), the AMF 1508 may reattempt tracing for logged MDT by sending another Trace Start message 1530 for logged MDT (e.g., with the measurement configuration) to the new serving RAN 1504.

[0121] Fig.16 Example operations 1600 are shown for coordinating logged MDT traces for inactive state UEs in accordance with certain aspects of the present disclosure. In this case, an Xn context retrieval procedure is utilized to transmit traces for logged MDT to a new serving RAN 1504. For example, after the anchor RAN 1506 receives the trace start message 1512, the anchor RAN 1506 may cache the MDT configuration and send a RAN paging message 1602 to the new serving RAN 1504 of the UE 1502, thereby triggering the RRC connection protocol for the UE 1502 to enter the RRC connected state. For example, the new serving RAN 1504 may send the paging message 1604 to the UE 1502 and receive an RRC resume request 1606 from the UE 1502.

[0122] The new serving RAN 1504 may then retrieve the UE context from the anchor RAN 1506 by sending a Retrieve UE Context Request message 1608 to the anchor RAN 1506. The new serving RAN 1504 may receive a UE Context Response 1610 with the context of the UE 1502. In this case, the UE Context Response 1610 may also indicate the measurement configuration for tracing to the new serving RAN 1504. The new serving RAN 1504 may then send an RRC Resume message 1612 to the UE 1502 and a Path Switch Request 1614 to the AMF entity 1508. The new serving RAN 1504 then sends a Logged Measurement Configuration message 1616 to the UE, configuring the UE to perform logged MDT. In certain aspects, the AMF entity may send another Trace Start message 1618 for logged MDT to the new serving RAN 1504.

[0123] Fig.17Example operations 1700 for deferring logged MDT tracking in accordance with certain aspects of the present disclosure are shown. In this case, logged MDT is delayed for configuration until the UE resumes at a later point in time. Once the UE resumes, the MDT context is transferred to the new serving RAN 1504 using a context retrieval procedure. In certain aspects, the AMF may indicate whether to allow delay of the logged MDT trigger. In other aspects, it is determined by the RAN whether to delay the logged MDT trigger based on the UE context.

[0124] As shown, once the anchor RAN 1506 receives the trace start message 1512 from the AMF entity 1508, at block 1702, the anchor RAN 1506 updates the previously cached UE context with the newly recorded MDT configuration. The anchor RAN 1506 then waits for the UE to transition to a connected state. For example, as shown, the UE 1502 may send an RRC resume request 1704 to the new serving RAN 1504. The new serving RAN 1504 then sends a UE context request 1706 to the anchor RAN 1506 and receives a UE context response 1708 having the recorded MDT configuration previously cached by the anchor RAN 1506. The new serving RAN 1504 then then sends an RRC resume message 1710 to the UE 1502, followed by sending a path switch request 1712 to the AMF entity 1508. The new serving RAN 1504 also sends a logged measurement configuration 1714 to the UE, configuring the UE to perform logged MDT. In certain aspects, the AMF entity may send another trace start message 1716 for logged MDT to the new serving RAN 1504.

[0125] Certain aspects provide techniques for handling ongoing MDT measurements (e.g., immediate MDT) when a UE enters an RRC inactive state. For example, once a UE configured for immediate MDT enters an RRC inactive state, the RAN may indicate to the AMF that tracking is deactivated due to a state transition of the UE to the RRC inactive state and that the immediate MDT configuration is released.

[0126] In other aspects, the RAN may suspend the immediate MDT configuration and cache the MDT configuration in the UE context. The MDT configuration may be transferred to the UE's new serving RAN. Once the UE resumes (e.g., enters a connected state), the configured immediate MDT may be resumed by the new serving RAN.

[0127] In some aspects, if the UE transitions to the RRC inactive state, the RAN may not do anything. In other words, there may be no MDT measurements during the RRC inactive state, and when the UE enters the RRC connected state, whether to resume immediate MDT may be decided by the new serving RAN.

[0128] Certain aspects of the present disclosure are directed to operations for the following scenario: a scenario where a UE configured with logged MDT enters an RRC inactive state. For example, logged MDT may be considered valid within an area configured by the AMF in the MDT configuration.

[0129] In some cases, within the overlapping area range of the area configured by the AMF and the UE RAN-based notification area (RNA) list configured by the RAN (e.g., a cell list defining the RNA), the logged MDT may only be conditionally valid. In other words, the UE may be configured with an RNA, and according to the RNA, if the UE moves from one RNA to another, the UE may notify the RAN. In other words, the RNA corresponds to the granularity at which the RAN is indicated and the RAN knows the location of the UE. In some cases, the RNA may be configured by the RAN to the UE when the UE enters the RRC inactive state. Therefore, only the RAN and the UE may know the RNA. If the UE is within the RNA, the RAN may start the logged MDT configuration for the UE when the UE enters the RRC inactive state with an RRC release message. In other words, the RRC release message sent by the RAN to the UE for transitioning the UE to the RRC inactive state may also include the logged MDT configuration. The UE may perform the logged MDT while in the RNA list. If the UE enters the RRC idle mode, the RNA-specific MDT configuration may be invalid. This protocol may be used to collect RNA-specific radio signal environment information.

[0130] Fig.18 A communication device 1800 is shown, which may include a device configured to perform operations for the techniques disclosed herein (e.g., Figure 8 1800). The communication device 1800 includes a processing system 1802 coupled to a transceiver 1808. The transceiver 1808 is configured to send and receive signals, such as various signals or messages as described herein, for the communication device 1800 via an antenna 1810. The processing system 1802 can be configured to perform processing functions for the communication device 1800, including processing signals received by the communication device 1800 and / or to be transmitted by the communication device 1800.

[0131] The processing system 1802 includes a processor 1804 coupled to a computer-readable medium / memory 1812 via a bus 1806. In some aspects, the computer-readable medium / memory 1812 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1804, causes the processor 1804 to perform the operations described herein or for performing operations described herein with respect to the present invention. Figure 8 Other operations of the various techniques discussed. In some aspects, the computer-readable medium / memory 1812 stores code 1815 for receiving a measurement configuration, code 1817 for collecting measurement information, and code 1819 for sending the measurement information. In some aspects, the processor 1804 has circuitry configured to implement the code stored in the computer-readable medium / memory 1812. The processor 1804 may include circuitry 1814 for receiving a measurement configuration, circuitry 1816 for collecting measurement information, and circuitry 1818 for sending measurement information.

[0132] Fig.19 A communication device 1900 is shown, which may include a device configured to perform operations for the techniques disclosed herein (eg, Fig. 9 1900). The communication device 1900 includes a processing system 1902 coupled to a transceiver 1908. The transceiver 1908 is configured to send and receive signals for the communication device 1900, such as various signals or messages as described herein, via an antenna 1910. The processing system 1902 can be configured to perform processing functions for the communication device 1900, including processing signals received by the communication device 1900 and / or to be sent by the communication device 1900.

[0133] The processing system 1902 includes a processor 1904 coupled to a computer-readable medium / memory 1912 via a bus 1906. In some aspects, the computer-readable medium / memory 1912 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 1904, causes the processor 1904 to perform the operations described herein or for performing operations described herein with respect to the present invention. Fig. 9Other operations of the various techniques discussed. In some aspects, the computer-readable medium / memory 1912 stores code 1915 for generating a message with a measurement configuration, code 1917 for sending the measurement configuration, and code 1919 for receiving a message with measurement information. In some aspects, the processor 1904 has circuitry configured to implement the code stored in the computer-readable medium / memory 1912. The processor 1904 may include circuitry 1914 for generating a message with a measurement configuration, circuitry 1916 for sending the measurement configuration, and circuitry 1918 for receiving a message with measurement information.

[0134] Fig. 20 A communication device 2000 is shown, which may include a processor configured to perform operations for the techniques disclosed herein (eg, Fig.10 2000). The communication device 2000 includes a processing system 2002 coupled to a transceiver 2008. The transceiver 2008 is configured to send and receive signals for the communication device 2000, such as various signals or messages as described herein, via an antenna 2010. The processing system 2002 can be configured to perform processing functions for the communication device 2000, including processing signals received by the communication device 2000 and / or to be sent by the communication device 2000.

[0135] The processing system 2002 includes a processor 2004 coupled to a computer-readable medium / memory 2012 via a bus 2006. In some aspects, the computer-readable medium / memory 2012 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 2004, causes the processor 2004 to perform the operations described herein or for performing operations described herein with respect to the computer-readable medium / memory 2012. Fig.10 Other operations of the various techniques discussed. In some aspects, the computer-readable medium / memory 2012 stores code 2015 for determining location information (e.g., via sensor 2090) and code 2017 for reporting location information. In some aspects, the processor 2004 has circuitry configured to implement the code stored in the computer-readable medium / memory 2012. The processor 2004 may include circuitry 2014 for determining location information and circuitry 2016 for reporting location information.

[0136] Fig.21 A communication device 2100 is shown, which may include a device configured to perform operations for the techniques disclosed herein (e.g., Fig.122100). The communication device 2100 includes a processing system 2102 coupled to a transceiver 2108. The transceiver 2108 is configured to send and receive signals for the communication device 2100 via an antenna 2110, such as various signals or messages as described herein. The processing system 2102 can be configured to perform processing functions for the communication device 2100, including processing signals received by the communication device 2100 and / or to be sent by the communication device 2100.

[0137] The processing system 2102 includes a processor 2104 coupled to a computer-readable medium / memory 2112 via a bus 2106. In some aspects, the computer-readable medium / memory 2112 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 2104, cause the processor 2104 to perform the operations described herein or to perform the operations described herein with respect to Fig.12 Other operations of the various techniques discussed. In some aspects, the computer-readable medium / memory 2112 stores code 2115 for detecting whether the UE is in an inactive state, code 2117 for determining a measurement configuration, code 2119 for generating a message including the measurement configuration, and code 2121 for sending a message to a wireless access network. In some aspects, the processor 2104 has circuits configured to implement the codes stored in the computer-readable medium / memory 2112. The processor 2104 may include circuits 2114 for detecting whether the UE is in an inactive state, circuits 2116 for determining a measurement configuration, circuits 2118 for generating a message including the measurement configuration, and circuits 2120 for sending a message to a wireless access network.

[0138] Fig. 22 A communication device 2200 is shown, which may include a device configured to perform operations for the techniques disclosed herein (e.g., Fig.13 2200). The communication device 2200 includes a processing system 2202 coupled to a transceiver 2208. The transceiver 2208 is configured to send and receive signals for the communication device 2200 via an antenna 2210, such as various signals or messages as described herein. The processing system 2202 can be configured to perform processing functions for the communication device 2200, including processing signals received by the communication device 2200 and / or to be sent by the communication device 2200.

[0139] The processing system 2202 includes a processor 2204 coupled to a computer-readable medium / memory 2212 via a bus 2206. In some aspects, the computer-readable medium / memory 2212 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 2204, causes the processor 2204 to perform the operations described herein or to perform the operations described herein with respect to Fig.13 Other operations of the various techniques discussed. In some aspects, the computer-readable medium / memory 2212 stores code 2215 for receiving a measurement configuration, code 2217 for determining a transition of the UE to an inactive state, and code 2219 for sending one or more messages to coordinate tracking of the UE or indicate a tracking failure. In some aspects, the processor 2204 has circuits configured to implement the codes stored in the computer-readable medium / memory 2212. The processor 2204 may include circuits 2214 for receiving a message for a measurement configuration, circuits 2216 for determining a transition of the UE to an inactive state, and circuits 2218 for sending one or more messages to coordinate tracking of the UE or indicate a tracking failure.

[0140] Fig.23 A communication device 2300 is shown, which may include a device configured to perform operations for the techniques disclosed herein (e.g., Fig.14 2300). The communication device 2300 includes a processing system 2302 coupled to a transceiver 2308. The transceiver 2308 is configured to send and receive signals for the communication device 2300 via an antenna 2310, such as various signals or messages as described herein. The processing system 2302 can be configured to perform processing functions for the communication device 2300, including processing signals received by the communication device 2300 and / or to be sent by the communication device 2300.

[0141] The processing system 2302 includes a processor 2304 coupled to a computer-readable medium / memory 2312 via a bus 2306. In some aspects, the computer-readable medium / memory 2312 is configured to store instructions (e.g., computer-executable code) that, when executed by the processor 2304, causes the processor 2304 to perform the operations described herein or to perform functions described herein with respect to the present invention. Fig.14Other operations of the various techniques discussed. In certain aspects, the computer-readable medium / memory 2312 stores code 2315 for receiving a message with a measurement configuration to start tracking of a UE, code 2317 for generating another message with the measurement configuration to start tracking, and code 2319 for sending the other message to the UE. In certain aspects, the processor 2304 has circuitry configured to implement the code stored in the computer-readable medium / memory 2312. The processor 2304 may include circuitry 2314 for receiving a message with a measurement configuration to start tracking of a UE, code 2316 for generating another message with the measurement configuration to start tracking, and code 2318 for sending the other message to the UE.

[0142] The methods disclosed herein include one or more steps or actions for implementing the described methods. The method steps and / or actions may be interchangeable without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order of specific steps and / or actions and / or the use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0143] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. For example, "at least one of a, b, or c" is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination of the same elements in multiples (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other ordering of a, b, and c).

[0144] As used herein, the term "determine" encompasses a wide variety of actions. For example, "determine" may include calculating, computing, processing, deriving, investigating, searching (e.g., querying in a table, a database, or another data structure), ascertaining, etc. In addition, "determine" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. In addition, "determine" may include resolving, selecting, choosing, establishing, etc.

[0145] The above description is provided so that any person skilled in the art can implement the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the present claims are not intended to be limited to the various aspects shown herein, but to conform to the full scope consistent with the language of the claims, wherein unless explicitly stated so, the reference to the singular element is not intended to mean "one and only one", but "one or more". Unless otherwise explicitly stated, the term "some" refers to one or more. All structural and functional equivalents of the elements of the various aspects described in the present disclosure, known to or later known to those of ordinary skill in the art, are expressly incorporated herein by reference, and are intended to be included by the claims. In addition, there is no content disclosed herein that is intended to be dedicated to the public, regardless of whether such disclosure is explicitly recorded in the claims. No claim element is to be interpreted according to 35 U.S.C. § 112, the sixth paragraph, unless the element is explicitly recorded using the phrase "unit for...", or in the case of a method claim, the element is recorded using the phrase "step for...".

[0146] The various operations of the methods described above may be performed by any suitable unit capable of performing the corresponding functions. The unit may include various hardware components and / or software components and / or hardware modules and / or software modules, including but not limited to circuits, application specific integrated circuits (ASICs) or processors. Generally, where operations are shown in the accompanying drawings, these operations may have corresponding counterpart functional module components with similar numbers.

[0147] The various illustrative logical blocks, modules, and circuits described in conjunction 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 an 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, such as 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.

[0148] If implemented in hardware, an example hardware configuration may include a processing system in a 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 and overall design constraints of the processing system. 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 a network adapter and other things 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 user terminal 120 (see Figure 1 ), a user interface (e.g., keyboard, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and therefore will not be described any further. The processor may be implemented using one or more general purpose processors and / or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits that can execute software. Those skilled in the art will recognize how to best implement the described functionality for the processing system depending on the specific application and the overall design constraints imposed on the entire system.

[0149] If implemented in software, the function may be stored on or sent via a computer-readable medium as one or more instructions or codes. Whether referred to as software, firmware, middleware, microcode, hardware description language or other, software should be broadly interpreted as meaning instructions, data or any combination thereof. Computer-readable media include both computer storage media and communication media, and the communication media include any media that facilitates the transfer of computer programs from one place to another. The processor may be responsible for managing the bus and general processing, including the execution of software modules stored on a machine-readable storage medium. The computer-readable storage medium may be coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. In an alternative manner, the storage medium may be indispensable to the processor. For example, the machine-readable medium may include a transmission line, a carrier modulated by data, and / or a computer-readable storage medium having instructions stored thereon separated from a wireless node, all of which may be accessed by the processor via a bus interface. Alternatively, or in addition, the machine-readable medium or any part thereof may be integrated into the processor, such as the case may be with a cache and / or a general register file. For example, examples of machine-readable storage media may include 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 media, or any combination thereof. Machine-readable media may be embodied in a computer program product.

[0150] A software module may include a single instruction or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media. A computer-readable medium may include multiple software modules. A software module includes instructions that, when executed by a device (such as a processor), cause a processing system to perform various functions. A software module may include a sending module and a receiving module. Each software module may exist in a single storage device, or may be distributed across multiple storage devices. For example, a software module may be loaded from a hard drive into a RAM when a triggering event occurs. During execution of the 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 register file for execution by the processor. When referring to the functions of the software modules below, it will be understood that such functions are implemented by the processor when executing instructions from the software modules.

[0151] Additionally, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies (such as infrared (IR), radio and microwave), then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies (such as infrared, radio and microwave) are included in the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray Optical disks, where magnetic disks typically reproduce data magnetically, and optical disks use lasers to reproduce data optically. Thus, in some aspects, computer-readable media may include non-transitory computer-readable media (e.g., tangible media). Additionally, for other aspects, computer-readable media may include transitory computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0152] Thus, certain 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 instructions stored (and / or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein. For example, instructions for performing the operations described herein.

[0153] Further, it should be appreciated that the modules and / or other appropriate units for performing the methods and techniques described herein can be downloaded and / or otherwise obtained by, for example, applicable user terminals and / or base stations. For example, such a device can be coupled to a server to facilitate the transmission of the units for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage unit (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or a floppy disk, etc.), so that the user terminal and / or base station can obtain the various methods when the storage unit is coupled to the device or provided to the device. In addition, any other suitable technology for providing the methods and techniques described herein to the device can be utilized.

[0154] It is to be understood that the present claims are not limited to the precise configuration and components shown above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the present claims.

Claims

1. A method for wireless communication, comprising: Receiving, by a user equipment (UE) from a network entity, a logged minimization of drive tests (MDT) configuration, the MDT configuration configuring the UE to determine location information of the UE for MDT measurements; determining, by the UE, location information of the UE in an area outside the coverage area corresponding to an area without cell coverage according to the recorded MDT configuration based on the location of the UE and data from one or more sensors of the UE; as well as The UE reports the location information to the network entity, wherein: The area outside the coverage area corresponds to an area where no satellite positioning system is available; as well as The location of the UE corresponds to a location with available satellite positioning system or cell coverage.

2. The method according to claim 1, wherein: The one or more sensors include at least one of a gyro sensor or a compass.

3. The method according to claim 1, wherein: The data from the one or more sensors indicates at least one of: a direction, an altitude, or a speed of the UE at one or more points in time between a time when the UE is in the area outside the coverage area and a time when the UE is in the location.

4. The method according to claim 1, wherein: The location information is reported to the network entity according to the MDT protocol.

5. The method according to claim 1, wherein: Determining the location information includes calculating, via the data from the one or more sensors, a relative position associated with the area outside of the coverage area with respect to the location of the UE.

6. An apparatus for wireless communication at a user equipment (UE), comprising: a memory including instructions; and One or more processors, which are individually or collectively configured to execute the instructions and cause the apparatus to perform the following operations: receiving a logged minimization of drive tests (MDT) configuration from a network entity, the MDT configuration configuring the UE to determine location information of the UE for MDT measurements; determining, according to the recorded MDT configuration, location information of the UE in an area outside the coverage area corresponding to an area without cell coverage based on the location of the UE and data from one or more sensors of the UE; as well as reporting the location information to the network entity, wherein: The area outside the coverage area corresponds to an area where no satellite positioning system is available; as well as The location of the UE corresponds to a location with available satellite positioning system or cell coverage.

7. The device according to claim 6, wherein: The one or more sensors include at least one of a gyro sensor or a compass.

8. The device according to claim 6, wherein: The data from the one or more sensors indicates at least one of: a direction, an altitude, or a speed of the UE at one or more points in time between a time when the UE is in the area outside the coverage area and a time when the UE is in the location.

9. The device according to claim 6, wherein: The location information is reported to the network entity according to the MDT protocol.

10. The device according to claim 6, wherein: Determining the location information includes calculating, via the data from the one or more sensors, a relative position associated with the area outside of the coverage area with respect to the location of the UE.

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