WO2021237440A1

WO2021237440A1 - Method to improve cell selection for 5g

Info

Publication number: WO2021237440A1
Application number: PCT/CN2020/092261
Authority: WO
Inventors: Guojing LIU; Chaofeng HUI; Dongsheng Wang; Xiaomeng Lu; Xuesong Chen; Wei Dong; Dunfa SHI; Ke Zhang; Wenbo DUAN
Original assignee: Qualcomm Incorporated
Priority date: 2020-05-26
Filing date: 2020-05-26
Publication date: 2021-12-02

Abstract

In one aspect, a method for wireless communication by a user equipment (UE) in a network includes establishing a first connection to a first cell, wherein the UE is operating in Evolved Universal Terrestrial Radio Access (E-UTRA) New Radio (NR) dual connectivity (ENDC) mode. The method also includes determining a channel quality associated with the first cell based on one or more reference signals received from the first cell, and determining whether the channel quality is less than a threshold. The method includes determining whether a cell reselection condition is satisfied in response to the channel quality being less than the threshold. The method further includes establishing a second connection to a second cell in response to the cell reselection condition being satisfied, wherein the second cell is one of a Universal Mobile Telecommunications System (UMTS) cell or a Global Systems for Mobile (GSM) cell. Other aspects and features are also claimed and described.

Description

METHOD TO IMPROVE CELL SELECTION FOR 5G

TECHNICAL FIELD

Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to cell selection and reselection. Certain embodiments of the technology discussed below can enable and provide improved cell selection for various 5G operating modes.

INTRODUCTION

Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources.

A wireless communication network may include a number of base stations or node Bs that can support communication for a number of user equipments (UEs) . A UE may communicate with a base station via downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.

A base station may transmit data and control information on the downlink to a UE and/or may receive data and control information on the uplink from the UE. On the downlink, a transmission from the base station may encounter interference due to transmissions from neighbor base stations or from other wireless radio frequency (RF) transmitters. On the uplink, a transmission from the UE may encounter interference from uplink transmissions of other UEs communicating with the neighbor base stations or from other wireless RF transmitters. This interference may degrade performance on both the downlink and uplink.

As the demand for mobile broadband access continues to increase, the possibilities of interference and congested networks grows with more UEs accessing the long-range wireless communication networks and more short-range wireless systems being deployed in communities. Research and development continue to advance wireless technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications.

BRIEF SUMMARY OF SOME EMBODIMENTS

The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the disclosure and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

In one aspect of the disclosure, a method for wireless communication by a user equipment (UE) in a network includes: establishing a first connection to a first cell, wherein the UE is operating in Evolved Universal Terrestrial Radio Access (E-UTRA) New Radio (NR) dual connectivity (ENDC) mode; determining a channel quality associated with the first cell based on one or more reference signals received from the first cell; determining whether the channel quality is less than a threshold; determining whether a cell reselection condition is satisfied in response to the channel quality being less than the threshold; and establishing a second connection to a second cell in response to the cell reselection condition being satisfied, wherein the second cell is one of a Universal Mobile Telecommunications System (UMTS) cell or a Global Systems for Mobile (GSM) cell.

In another aspect of the disclosure, a method for wireless communication includes establishing, by a user equipment (UE) , a communication link with a network entity; receiving, by the UE, a threshold parameter associated with cell reselection for the network entity; performing, by the UE, an RSRP determination based on the threshold parameter; performing, by the UE, an SNR determination based on a second threshold parameter; and determining, by the UE, whether to move to another cell based on the RSRP determination and the SNR determination.

In another aspect of the disclosure, a method for wireless communication includes, establishing, by a user equipment (UE) , a communication link with a network entity; receiving, by the UE, a threshold parameter of channel quality for the network entity; performing, by the UE, a receive level determination based on the threshold parameter; performing, by the UE, a quality level determination based on the threshold parameter; and determining whether to move to another cell based on the receive level determination and the quality level determination.

Other aspects, features, and embodiments will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary embodiments in conjunction with the accompanying figures. While features may be discussed relative to certain embodiments and figures below, all embodiments can include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various embodiments. In similar fashion, while exemplary embodiments may be discussed below as device, system, or method embodiments the exemplary embodiments can be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the present disclosure may be realized by reference to the following drawings. In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

FIG. 1 is a block diagram illustrating details of a wireless communication system according to some embodiments of the present disclosure.

FIG. 2 is a block diagram conceptually illustrating a design of a base station and a UE configured according to some embodiments of the present disclosure.

FIG. 3 is a ladder diagram of an example of cell selection.

FIG. 4 is a block diagram illustrating an example of a wireless communications system (with a UE and base station) with improved cell selection.

FIG. 5 is a diagram of an example of a ladder diagram of improved cell selection according to some embodiments of the present disclosure.

FIG. 6 is a diagram of another example of a ladder diagram of improved cell selection according to some embodiments of the present disclosure.

FIG. 7 is a flow diagram illustrating example blocks executed by a UE configured according to an aspect of the present disclosure.

FIG. 8 is a flow diagram illustrating another example of blocks executed by a UE configured according to an aspect of the present disclosure.

FIG. 9 is a block diagram conceptually illustrating a design of a UE configured to perform improved cell selection operations according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with the appended drawings and appendix, is intended as a description of various configurations and is not intended to limit the scope of the disclosure. Rather, the detailed description includes specific details for the purpose of providing a thorough understanding of the inventive subject matter. It will be apparent to those skilled in the art that these specific details are not required in every case and that, in some instances, well-known structures and components are shown in block diagram form for clarity of presentation.

This disclosure relates generally to providing or participating in communication as between two or more wireless devices in one or more wireless communications systems, also referred to as wireless communications networks. In various embodiments, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, 5 ^th Generation (5G) or new radio (NR) networks (sometimes referred to as “5G NR” networks/systems/devices) , as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.

A CDMA network, for example, may implement a radio technology such as universal terrestrial radio access (UTRA) , cdma2000, and the like. UTRA includes wideband-CDMA (W-CDMA) and low chip rate (LCR) . CDMA2000 covers IS-2000, IS-95, and IS-856 standards.

A TDMA network may, for example implement a radio technology such as GSM. 3GPP defines standards for the GSM EDGE (enhanced data rates for GSM evolution) radio access network (RAN) , also denoted as GERAN. GERAN is the radio component of GSM/EDGE, together with the network that joins the base stations (for example, the Ater and Abis interfaces) and the base station controllers (A interfaces, etc. ) . The radio access network represents a component of a GSM network, through which phone calls and packet data are routed from and to the public switched telephone network (PSTN) and Internet to and from subscriber handsets, also known as user terminals or user equipments (UEs) . A mobile phone operator's network may comprise one or more GERANs, which may be coupled with Universal Terrestrial Radio Access Networks (UTRANs) in the case of a UMTS/GSM network. An operator network may also include one or more LTE networks, and/or one or more other networks. The various different network types may use different radio access technologies (RATs) and radio access networks (RANs) .

An OFDMA network may implement a radio technology such as evolved UTRA (E-UTRA) , IEEE 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and Global System for Mobile Communications (GSM) are part of universal mobile telecommunication system (UMTS) . In particular, long term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from an organization named “3rd Generation Partnership Project” (3GPP) , and cdma2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . These various radio technologies and standards are known or are being developed. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the universal mobile telecommunications system (UMTS) mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.

5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. To achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for 5G NR networks. The 5G NR will be capable of scaling to provide coverage (1) to a massive Internet of things (IoTs) with an ultra-high density (e.g., ～1M nodes/km ²) , ultra-low complexity (e.g., ～10s of bits/sec) , ultra-low energy (e.g., ～10+ years of battery life) , and deep coverage with the capability to reach challenging locations; (2) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., ～99.9999%reliability) , ultra-low latency (e.g., ～ 1 ms) , and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (e.g., ～ 10 Tbps/km ²) , extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates) , and deep awareness with advanced discovery and optimizations.

5G NR devices, networks, and systems may be implemented to use optimized OFDM-based waveform features. These features may include scalable numerology and transmission time intervals (TTIs) ; a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD) /frequency division duplex (FDD) design; and advanced wireless technologies, such as massive multiple input, multiple output (MIMO) , robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz, for example over 1, 5, 10, 20 MHz, and the like bandwidth. For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHz bandwidth. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz bandwidth. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500MHz bandwidth.

The scalable numerology of 5G NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTI may be used for low latency and high reliability, while longer TTI may be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs to allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with uplink/downlink scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive uplink/downlink that may be flexibly configured on a per-cell basis to dynamically switch between uplink and downlink to meet the current traffic needs.

For clarity, certain aspects of the apparatus and techniques may be described below with reference to exemplary LTE implementations or in an LTE-centric way, and LTE terminology may be used as illustrative examples in portions of the description below; however, the description is not intended to be limited to LTE applications. Indeed, the present disclosure is concerned with shared access to wireless spectrum between networks using different radio access technologies or radio air interfaces, such as those of 5G NR.

Moreover, it should be understood that, in operation, wireless communication networks adapted according to the concepts herein may operate with any combination of licensed or unlicensed spectrum depending on loading and availability. Accordingly, it will be apparent to one of skill in the art that the systems, apparatus and methods described herein may be applied to other communications systems and applications than the particular examples provided.

While aspects and embodiments are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, embodiments and/or uses may come about via integrated chip embodiments and/or other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc. ) . While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregated, distributed, or OEM devices or systems incorporating one or more described aspects. In some practical settings, devices incorporating described aspects and features may also necessarily include additional components and features for implementation and practice of claimed and described embodiments. It is intended that innovations described herein may be practiced in a wide variety of implementations, including both large/small devices, chip-level components, multi-component systems (e.g. RF-chain, communication interface, processor) , distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution.

FIG. 1 shows wireless network 100 for communication according to some embodiments. Wireless network 100 may, for example, comprise a 5G wireless network. As appreciated by those skilled in the art, components appearing in FIG. 1 are likely to have related counterparts in other network arrangements including, for example, cellular-style network arrangements and non-cellular-style-network arrangements (e.g., device to device or peer to peer or ad hoc network arrangements, etc. ) .

Wireless network 100 illustrated in FIG. 1 includes a number of base stations 105 and other network entities. A base station may be a station that communicates with the UEs and may also be referred to as an evolved node B (eNB) , a next generation eNB (gNB) , an access point, and the like. Each base station 105 may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a base station and/or a base station subsystem serving the coverage area, depending on the context in which the term is used. In implementations of wireless network 100 herein, base stations 105 may be associated with a same operator or different operators (e.g., wireless network 100 may comprise a plurality of operator wireless networks) , and may provide wireless communications using one or more of the same frequencies (e.g., one or more frequency bands in licensed spectrum, unlicensed spectrum, or a combination thereof) as a neighboring cell. In some examples, an individual base station 105 or UE 115 may be operated by more than one network operating entity. In other examples, each base station 105 and UE 115 may be operated by a single network operating entity.

A base station may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a pico cell, would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a femto cell, would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) . A base station for a macro cell may be referred to as a macro base station. A base station for a small cell may be referred to as a small cell base station, a pico base station, a femto base station or a home base station. In the example shown in FIG. 1,

base stations

105d and 105e are regular macro base stations, while base stations 105a-105c are macro base stations enabled with one of 3 dimension (3D) , full dimension (FD) , or massive MIMO. Base stations 105a-105c take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. Base station 105f is a small cell base station which may be a home node or portable access point. A base station may support one or multiple (e.g., two, three, four, and the like) cells.

Wireless network 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. In some scenarios, networks may be enabled or configured to handle dynamic switching between synchronous or asynchronous operations.

UEs 115 are dispersed throughout the wireless network 100, and each UE may be stationary or mobile. It should be appreciated that, although a mobile apparatus is commonly referred to as user equipment (UE) in standards and specifications promulgated by the 3rd Generation Partnership Project (3GPP) , such apparatus may also be referred to by those skilled in the art as a mobile station (MS) , a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT) , a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, a gaming device, an augmented reality device, vehicular component device/module, or some other suitable terminology. Within the present document, a “mobile” apparatus or UE need not necessarily have a capability to move, and may be stationary. Some non-limiting examples of a mobile apparatus, such as may comprise embodiments of one or more of UEs 115, include a mobile, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a laptop, a personal computer (PC) , a notebook, a netbook, a smart book, a tablet, and a personal digital assistant (PDA) . A mobile apparatus may additionally be an “Internet of things” (IoT) or “Internet of everything” (IoE) device such as an automotive or other transportation vehicle, a satellite radio, a global positioning system (GPS) device, a logistics controller, a drone, a multi-copter, a quad-copter, a smart energy or security device, a solar panel or solar array, municipal lighting, water, or other infrastructure; industrial automation and enterprise devices; consumer and wearable devices, such as eyewear, a wearable camera, a smart watch, a health or fitness tracker, a mammal implantable device, gesture tracking device, medical device, a digital audio player (e.g., MP3 player) , a camera, a game console, etc.; and digital home or smart home devices such as a home audio, video, and multimedia device, an appliance, a sensor, a vending machine, intelligent lighting, a home security system, a smart meter, etc. In one aspect, a UE may be a device that includes a Universal Integrated Circuit Card (UICC) . In another aspect, a UE may be a device that does not include a UICC. In some aspects, UEs that do not include UICCs may also be referred to as IoE devices. UEs 115a-115d of the embodiment illustrated in FIG. 1 are examples of mobile smart phone-type devices accessing wireless network 100 A UE may also be a machine specifically configured for connected communication, including machine type communication (MTC) , enhanced MTC (eMTC) , narrowband IoT (NB-IoT) and the like. UEs 115e-115k illustrated in FIG. 1 are examples of various machines configured for communication that access wireless network 100.

A mobile apparatus, such as UEs 115, may be able to communicate with any type of the base stations, whether macro base stations, pico base stations, femto base stations, relays, and the like. In FIG. 1, a lightning bolt (e.g., communication link) indicates wireless transmissions between a UE and a serving base station, which is a base station designated to serve the UE on the downlink and/or uplink, or desired transmission between base stations, and backhaul transmissions between base stations. UEs may operate as base stations or other network nodes in some scenarios. Backhaul communication between base stations of wireless network 100 may occur using wired and/or wireless communication links.

In operation at wireless network 100, base stations 105a-105c serve

UEs

115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. Macro base station 105d performs backhaul communications with base stations 105a-105c, as well as small cell, base station 105f. Macro base station 105d also transmits multicast services which are subscribed to and received by

UEs

115c and 115d. Such multicast services may include mobile television or stream video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

Wireless network 100 of embodiments supports mission critical communications with ultra-reliable and redundant links for mission critical devices, such UE 115e, which is a drone. Redundant communication links with UE 115e include from

macro base stations

105d and 105e, as well as small cell base station 105f. Other machine type devices, such as UE 115f (thermometer) , UE 115g (smart meter) , and UE 115h (wearable device) may communicate through wireless network 100 either directly with base stations, such as small cell base station 105f, and macro base station 105e, or in multi-hop configurations by communicating with another user device which relays its information to the network, such as UE 115f communicating temperature measurement information to the smart meter, UE 115g, which is then reported to the network through small cell base station 105f. Wireless network 100 may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as in a vehicle-to-vehicle (V2V) mesh network between UEs 115i-115k communicating with macro base station 105e.

FIG. 2 shows a block diagram of a design of a base station 105 and a UE 115, which may be any of the base stations and one of the UEs in FIG. 1. For a restricted association scenario (as mentioned above) , base station 105 may be small cell base station 105f in FIG. 1, and UE 115 may be UE 115c or 115D operating in a service area of base station 105f, which in order to access small cell base station 105f, would be included in a list of accessible UEs for small cell base station 105f. Base station 105 may also be a base station of some other type. As shown in FIG. 2, base station 105 may be equipped with antennas 234a through 234t, and UE 115 may be equipped with antennas 252a through 252r for facilitating wireless communications.

At base station 105, transmit processor 220 may receive data from data source 212 and control information from controller/processor 240. The control information may be for the physical broadcast channel (PBCH) , physical control format indicator channel (PCFICH) , physical hybrid-ARQ (automatic repeat request) indicator channel (PHICH) , physical downlink control channel (PDCCH) , enhanced physical downlink control channel (EPDCCH) , MTC physical downlink control channel (MPDCCH) , etc. The data may be for the PDSCH, etc. Transmit processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Transmit processor 220 may also generate reference symbols, e.g., for the primary synchronization signal (PSS) and secondary synchronization signal (SSS) , and cell-specific reference signal. Transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream. Each modulator 232 may additionally or alternatively process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 232a through 232t may be transmitted via antennas 234a through 234t, respectively.

At UE 115, the antennas 252a through 252r may receive the downlink signals from base station 105 and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc. ) to obtain received symbols. MIMO detector 256 may obtain received symbols from demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 115 to data sink 260, and provide decoded control information to controller/processor 280.

On the uplink, at UE 115, transmit processor 264 may receive and process data (e.g., for the physical uplink shared channel (PUSCH) ) from data source 262 and control information (e.g., for the physical uplink control channel (PUCCH) ) from controller/processor 280. Transmit processor 264 may also generate reference symbols for a reference signal. The symbols from transmit processor 264 may be precoded by TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for SC-FDM, etc. ) , and transmitted to base station 105. At base station 105, the uplink signals from UE 115 may be received by antennas 234, processed by demodulators 232, detected by MIMO detector 236 if applicable, and further processed by receive processor 238 to obtain decoded data and control information sent by UE 115. Processor 238 may provide the decoded data to data sink 239 and the decoded control information to controller/processor 240.

Controllers/

processors

240 and 280 may direct the operation at base station 105 and UE 115, respectively. Controller/processor 240 and/or other processors and modules at base station 105 and/or controller/processor 280 and/or other processors and modules at UE 115 may perform or direct the execution of various processes for the techniques described herein, such as to perform or direct the execution illustrated in FIGS. 7 and 8, and/or other processes for the techniques described herein.

Memories

242 and 282 may store data and program codes for base station 105 and UE 115, respectively. Scheduler 244 may schedule UEs for data transmission on the downlink and/or uplink.

Wireless communications systems operated by different network operating entities (e.g., network operators) may share spectrum. In some instances, a network operating entity may be configured to use an entirety of a designated shared spectrum for at least a period of time before another network operating entity uses the entirety of the designated shared spectrum for a different period of time. Thus, in order to allow network operating entities use of the full designated shared spectrum, and in order to mitigate interfering communications between the different network operating entities, certain resources (e.g., time) may be partitioned and allocated to the different network operating entities for certain types of communication.

For example, a network operating entity may be allocated certain time resources reserved for exclusive communication by the network operating entity using the entirety of the shared spectrum. The network operating entity may also be allocated other time resources where the entity is given priority over other network operating entities to communicate using the shared spectrum. These time resources, prioritized for use by the network operating entity, may be utilized by other network operating entities on an opportunistic basis if the prioritized network operating entity does not utilize the resources. Additional time resources may be allocated for any network operator to use on an opportunistic basis.

Access to the shared spectrum and the arbitration of time resources among different network operating entities may be centrally controlled by a separate entity, autonomously determined by a predefined arbitration scheme, or dynamically determined based on interactions between wireless nodes of the network operators.

In some cases, UE 115 and base station 105 may operate in a shared radio frequency spectrum band, which may include licensed or unlicensed (e.g., contention-based) frequency spectrum. In an unlicensed frequency portion of the shared radio frequency spectrum band, UEs 115 or base stations 105 may traditionally perform a medium-sensing procedure to contend for access to the frequency spectrum. For example, UE 115 or base station 105 may perform a listen before talk (LBT) procedure such as a clear channel assessment (CCA) prior to communicating in order to determine whether the shared channel is available. A CCA may include an energy detection procedure to determine whether there are any other active transmissions. For example, a device may infer that a change in a received signal strength indicator (RSSI) of a power meter indicates that a channel is occupied. Specifically, signal power that is concentrated in a certain bandwidth and exceeds a predetermined noise floor may indicate another wireless transmitter. A CCA also may include detection of specific sequences that indicate use of the channel. For example, another device may transmit a specific preamble prior to transmitting a data sequence. In some cases, an LBT procedure may include a wireless node adjusting its own backoff window based on the amount of energy detected on a channel and/or the acknowledge/negative-acknowledge (ACK/NACK) feedback for its own transmitted packets as a proxy for collisions.

FIG. 3 illustrates an example ladder diagram 300 for cell selection. Referring to FIG. 3, the ladder diagram 300 illustrates cell selection and cell reselection operations for a particular UE. Cell reselection operations may involve a UE operating in a RRC idle mode (e.g., RRC idle state. In the example of FIG. 3, the first cell is an LTE anchor cell (e.g., LTE or 4G base station, aka a eNB) , and the second cell is a 2G or 3G cell, such as UMTS or GSM base station.

As shown in FIG. 3, the UE selects the LTE anchor cell. For example, the UE selects the LTE anchor cell on power on, in response to a cell selection, or based on a handover procedure. Such selection may be referred to as camping on the cell. After selection of the cell, the UE registers with the cell.

While camped on the LTE cell, the UE may periodically perform cell selection /reselection procedures. For example, the UE may perform cell selection /reselection procedures in response to changing an RRC state, in response to a timer expiring, every N number of slots or frames, or based on a quality determination (s) . Such cell selection /reselection procedures may involve IRAT to GSM handover procedures. In one particular example shown in FIG. 3, the UE performs a quality level based cell selection (reselection) procedure. The UE determines if a first quality level metric (i.e., Squal) of the serving cell, Squal_serving, is less than a first threshold level and if a second quality level metric (Squal) of a non-serving cell, Squal_non-serving, is greater than a second threshold level. In the example of FIG. 3, the quality metrics are Reference Signals Received Quality (RSRQ) based and the thresholds are cell reselection thresholds for the serving cell and for non-serving cells, such as Thresh_serving, LowQ and Thresh_x, LowQ.

In response to satisfying neither of the conditions or only one conditions, the quality level determination is repeated in response to another trigger condition. In response to satisfying both conditions, the UE advances to cell selection /reselection of the second cell /non-serving cell. For example, the UE determines to camp on the second cell. The UE may register with the second cell. As shown in the example of FIG. 3, while the UE is camped on the LTE anchor cell, the UE may be in an ENDC mode.

In response to the UE selection or camping on the second cell, such as a lower generation and/or lower priority cell, the UE may initiate or start a high priority RAT timer. In response to expiration of the high priority RAT timer, the UE moves back to the LTE anchor cell. For example, the UE determines to camp on the LTE anchor cell. The UE may register (reregister) with the LTE anchor cell.

However, as shown in FIG. 3, such a procedure (procedure 1) of moving back and forth between two cells may be repeated when the quality of the serving cell is below the threshold. To illustrate, the UE may bounce back and forth between cells after expiration of the timer. Thus, in the example in FIG. 3, the UE may have poor and inconsistent service and take up network bandwidth by switching back and forth. Therefore, such operations consume increased bandwidth and power while providing a poor experience.

FIG. 4 illustrates an example of a wireless communications system 400 that supports improved cell selection and reselection with aspects of the present disclosure. In some examples, wireless communications system 400 may implement aspects of wireless communication system 100. For example, wireless communications system 400 may include UE 115 and network entity 405. Improved cell selection and reselection operations may reduce network overhead, and thus may increase throughput and reliability by reducing cell switching operations.

Network entity 405 and UE 115 UE 115 may be configured to communicate via frequency bands, such as FR1 having a frequency of 410 to 7125 MHz or FR2 having a frequency of 24250 to 52600 MHz for mm-Wave. It is noted that sub-carrier spacing (SCS) may be equal to 15, 30, 60, or 120 kHz for some data channels. Network entity 405 and UE 115 may be configured to communicate via one or more component carriers (CCs) , such as representative first CC 481, second CC 482, third CC 483, and fourth CC 484. Although four CCs are shown, this is for illustration only, more or fewer than four CCs may be used. One or more CCs may be used to communicate control channel transmissions, data channel transmissions, and/or sidelink channel transmissions.

Such transmissions may include a Physical Downlink Control Channel (PDCCH) , a Physical Downlink Shared Channel (PDSCH) , a Physical Uplink Control Channel (PUCCH) , a Physical Uplink Shared Channel (PUSCH) , a Physical Sidelink Control Channel (PSCCH) , a Physical Sidelink Shared Channel (PSSCH) , or a Physical Sidelink Feedback Channel (PSFCH) . Such transmissions may be scheduled by aperiodic grants and/or periodic grants.

Each periodic grant may have a corresponding configuration, such as configuration parameters/settings. The periodic grant configuration may include configured grant (CG) configurations and settings. Additionally, or alternatively, one or more periodic grants (e.g., CGs thereof) may have or be assigned to a CC ID, such as intended CC ID.

Each CC may have a corresponding configuration, such as configuration parameters/settings. The configuration may include bandwidth, bandwidth part, HARQ process, TCI state, RS, control channel resources, data channel resources, or a combination thereof. Additionally, or alternatively, one or more CCs may have or be assigned to a Cell ID, a Bandwidth Part (BWP) ID, or both. The Cell ID may include a unique cell ID for the CC, a virtual Cell ID, or a particular Cell ID of a particular CC of the plurality of CCs. Additionally, or alternatively, one or more CCs may have or be assigned to a HARQ ID. Each CC may also have corresponding management functionalities, such as, beam management, BWP switching functionality, or both. In some implementations, two or more CCs are quasi co-located, such that the CCs have the same beam and/or same symbol.

In some implementations, control information may be communicated via network entity 405 and UE 115. For example, the control information may be communicated suing MAC-CE transmissions, RRC transmissions, DCI, transmissions, another transmission, or a combination thereof.

UE 115 can include a variety of components (e.g., structural, hardware components) used for carrying out one or more functions described herein. For example, these components can includes processor 402, memory 404, transmitter 410, receiver 412, encoder, 413, decoder 414, Cell Selector 415, Timer 416, and antennas 252a-r. Processor 402 may be configured to execute instructions stored at memory 404 to perform the operations described herein. In some implementations, processor 402 includes or corresponds to controller/processor 280, and memory 404 includes or corresponds to memory 282. Memory 404 may also be configured to store receive level metric data 406, quality level metric data 408, cell selection data 442, settings data 444, or a combination thereof, as further described herein.

The receive level metric data 406 includes or corresponds to data associated with or receive level metrics. For example, the receive level metric data 406 may include Reference Signals Received Power (RSRP) metric data, RSRP threshold data, measured /calculated RSRP data, intermediate receive level values data, etc. The quality level metric data 408 includes or corresponds to data associated with or corresponding to quality level metrics. For example, the quality level metric data 408 may include quality level metric data, measured /calculated quality level, intermediate quality level values data, etc.

The cell selection data 442 includes or corresponds to data associated with cell selection conditions, such as the example conditions illustrated and described in FIGS. 3, 5, and 6. The cell selection data 442 may also include to correspond to data indicating a cell selection or a result of a cell selection determination. The settings data 444 includes or corresponds to data associated with cell selection /reselection operations. For example, the settings data 444 may indicate one or more threshold values, one or more cell selection /reselection modes, or a combination thereof.

Transmitter 410 is configured to transmit data to one or more other devices, and receiver 412 is configured to receive data from one or more other devices. For example, transmitter 410 may transmit data, and receiver 412 may receive data, via a network, such as a wired network, a wireless network, or a combination thereof. For example, UE 115 may be configured to transmit and/or receive data via a direct device-to-device connection, a local area network (LAN) , a wide area network (WAN) , a modem-to-modem connection, the Internet, intranet, extranet, cable transmission system, cellular communication network, any combination of the above, or any other communications network now known or later developed within which permits two or more electronic devices to communicate. In some implementations, transmitter 410 and receiver 412 may be replaced with a transceiver. Additionally, or alternatively, transmitter 410, receiver, 412, or both may include or correspond to one or more components of UE 115 described with reference to FIG. 2.

Encoder 413 and decoder 414 may be configured to encode and decode data for transmission. Cell selector 415 may be configured to determine and perform cell selection (re-selection) operations. For example, cell selector 415 is configured to perform cell selections (re-selection) operations when the UE is in an RRC idle mode (e.g., RRC idle state) . For example, cell selector 415 may cause UE 115 to monitor for reference signals, determine channel conditions, and evaluate cell selection (reselection) conditions and preconditions based on the channel conditions. Timer 416 may be configured to carry out timer operations with respect to cell selection. For example, timer 416 is configured to perform RAT selection timer operations. To illustrate, timer 416 is a high priority RAT timer and configured to initiate upon cell selection of a lower priority cell and expiration of the timer 416 causes the UE 115 to switch to a higher priority cell.

Network entity 405 includes processor 430, memory 432, transmitter 434, receiver 436, encoder 437, decoder 438, and antennas 234a-t. Processor 430 may be configured to execute instructions stores at memory 432 to perform the operations described herein. In some implementations, processor 430 includes or corresponds to controller/processor 240, and memory 432 includes or corresponds to memory 242. Memory 432 may be configured to store reference signals data 407, cell selection data 408, settings data 444, or a combination thereof, similar to the UE 115 and as further described herein. Reference signals data 406 may include or correspond to data for the generation and transmission of reference signals by the network entity 405.

Transmitter 434 is configured to transmit data to one or more other devices, and receiver 436 is configured to receive data from one or more other devices. For example, transmitter 434 may transmit data, and receiver 436 may receive data, via a network, such as a wired network, a wireless network, or a combination thereof. For example, network entity 405 may be configured to transmit and/or receive data via a direct device-to-device connection, a local area network (LAN) , a wide area network (WAN) , a modem-to-modem connection, the Internet, intranet, extranet, cable transmission system, cellular communication network, any combination of the above, or any other communications network now known or later developed within which permits two or more electronic devices to communicate. In some implementations, transmitter 434 and receiver 436 may be replaced with a transceiver. Additionally, or alternatively, transmitter 434, receiver, 436, or both may include or correspond to one or more components of network entity 405 described with reference to FIG. 2. Encoder 437, and decoder 438 may include the same functionality as described with reference to encoder 413 and decoder 414, respectively.

UE 115 and/or Network entity 405 may determine to use improved cell selection (reselection) operations. For example, the UE 115 or the network entity 405 may determine to use improved cell selection (reselection) operations based on network load, congestion, device mobility, bandwidth allocation, one or more other metrics, or a combination thereof. Additionally, or alternatively, the UE 115 or the network entity 405 may be set to always use improved cell selection (reselection) operations or may be switched to use improved cell selection (reselection) operations responsive to manual input.

During operation of wireless communications system 400, devices of wireless communications system 400, establish communication links. For example, UE 115 and network entity 405 perform link establishing operations. To illustrate, UE 115 perform conventional link establishing operations. One such example is the UE 115 listens for SSB bursts from the network entity 405 and requests to join the network entity 405.

During operation of wireless communications system 400, network entity 405 may determine that UE 115 has improved cell selection /reselection capability. For example, UE 115 may transmit a message 448 that includes a cell reselection type indicator 490. Indicator 490 may indicate enhanced cell reselection capability or a particular type or mode of cell reselection. In some implementations, network entity 405 sends control information to indicate to UE 115 that enhanced cell reselection and/or a particular type of enhanced cell reselection is to be used. For example, in some implementations, message 448 (or another message, such as configuration transmission 450) is transmitted by the network entity 405. The configuration transmission 450 may include or indicate to use enhanced cell reselection or to adjust or implement a setting of a particular type of enhanced cell reselection.

During establishment of the communication link (s) , the network entity 405 may transmit one or more system messages to the UE 115. As illustrated in the example of FIG. 4, the network entity 405 transmits a system information block (SIB) three message 452 (SIB3) to the UE 115. The SIB3 message 452 may include or indicate one or more parameters to be used by the UE 115 for cell selection (reselection) operations. For example, the SIB3 message 452 may indicate, a quality threshold for the serving cell when reselecting towards a lower priority RAT/frequency, a quality threshold for non-serving cells over each frequency of E-UTRAN and UTRAN and GERAN, or a combination thereof. Alternatively, such a message or parameter (s) may be sent after communication links are established.

After the communication links are established, UE 115 and network entity 405 may periodically perform operations to maintain the communication link. To illustrate, network entity 405 may periodically send reference signal (s) 454, which the UE 115 may use to determine channel quality and conditions, such as physical parameters of the channel. The UE 115, such as the cell selector 415 thereof, may also use such channel quality information for cell selection /reselection.

For example, the UE 115 may determine to use a receive level metric (e.g., an RSRP or SNR based metric) for cell selection determination. To illustrate, the UE 115 may determine to use an RSRP based metric condition to determine whether to perform cell selection (reselection) operations. As another illustration, the UE 115 may determine to use an SNR based metric condition, in addition to or in the alternative of the RSRP based metric condition, to determine whether to perform cell selection (reselection) operations. In response to satisfying the RSRP based metric condition or SNR based metric condition, the UE 115 may proceed to cell selection (reselection) operations, such as conventional quality level, RSRQ metric /Squal, based determinations as illustrated in FIG. 3.

In some implementations, the RSRP metric may be a cell selection receive level value (Srxlev) . Additionally, or alternatively, the RSRQ metric may be a cell selection quality value (Squal) .

The cell selection receive level value (Srxlev, e.g., dB) is determined based on a measured cell receive level value (Qrxlevmeas, e.g., RSRP) , a minimum required receive level in the cell (Qrxlevmin in dBm) , a receive level offset value (Qrxlevminoffset) , a power compensation value (Pcompensation) , or a combination thereof.

The cell selection quality value (Squal e.g., dB) is determined based on a measured cell quality value (Qqualmeas, e.g., RSRQ) , a minimum required quality level in the cell (Qqualmin, e.g., dB) , a quality value offset value (Qqualminoffset) , or a combination thereof.

The power compensation value (Pcompensation) is determined based on a maximum RF output power of the UE (dBm) according to a UE power class (PPowerClass) .

In some implementations, the cell selection receive level value, the cell selection quality value, or both, may further determined based on a temporary offset value (Qoffsettemp) . Such offset value is often set to zero.

In response to satisfying the precursor determination and the cell selection determinations, the UE 115 determines to switch to another cell, such as second network entity 105. As illustrated in the example of FIG. 4, the UE 115 transmits a first cell reselection message 456 to the second network entity 105 to register and camp on the second network entity 105.

In response to switching to the second network entity 105, the UE 115 may initiate timer 416. For example, the timer 416 may be a high priority RAT determination timer, and the expiration of such timer may indicate to the UE 115 to switch back to the first cell. As illustrated in the example of FIG. 4, the UE 115 transmits a second cell re-selection message 458 to the network entity 405 to register and camp on the network entity 405.

While the UE 115 is registered and camped on the respective network entities /cells. The UE 115 may transmit and/or receive data channel transmissions 460. To illustrate, while the UE 115 is camped on the network entity 405, the UE 115 transmit and/or receive data channel transmissions 460 with the network entity 405 according to a first type of network, such as 4G /LTE, and while the UE 115 is camped on the second network entity 105, the UE 115 transmit and/or receive data channel transmissions 460 with the second network entity 105 according to a second type of network, such as 2G or 3G. The data channel transmissions 460 with the network entity 405 may have higher speeds, lower latency, and/or increased quality as compared to the data channel transmissions 460 with the second network entity 105.

As compared to the operations of FIG. 3, the system of FIG. 4 is capable of having the UE 115 stay camped on the network entity 405 (higher priority and/or higher functioning cell) longer and/or in more conditions. To illustrate, even if the quality level conditions are met, the UE 115 will stay on the first cell /network entity 405 if one or more of the receive level conditions are met. Accordingly, the UE 115 may have higher performance for longer periods of time and consume less power and network resources and bandwidth by performing less switching (e.g., bouncing back and forth) , as compared to the operations of FIG. 3.

Thus, FIG. 4 describes enhanced cell selection (re-selection) operations for network operations. Using enhanced cell selection (re-selection) operations may enable improvement when operating in multiple networks. Performing enhanced cell selection (re-selection) operations enables a network to improve throughput and reliability and a UE to reduce power consumption from switching cells.

FIGS. 5 and 6 illustrate example ladder diagrams for improved cell selection operations. Referring to FIG. 5, FIG. 5 is a diagram of an example of a ladder diagram 500 with a receive level determination for cell selection /reselection. Said another way, a different type of determination, as opposed to quality level determination, can be used for selection. As illustrated in the example of FIG. 5, the ladder diagram 500 illustrates a UE 115, a first cell 105a, and a second cell 105b.

At 510, the UE 115 receives a RRC configuration message from the first cell 105a. The RRC configuration message may include a particular threshold to be used for cell handover. For example, a receive level threshold, a quality level threshold, or a combination thereof, for the first cell 105a, the second cell 105b, or both.

At 515, the UE 115 optionally receives a second RRC configuration message from the second cell 105b. The second RRC configuration message may include a second particular threshold to be used for cell handover. For example, a receive level threshold, a quality level threshold, or both, for the second cell 105b.

In FIG. 5, the UE 115 may not have selected either cell or may already be camped on the first cell 105a. In the example of FIG. 5, the first cell 105a may be an LTE cell and the second cell 105b may be a previous generation cell (e.g., 2G or 3G cell) .

At 520, the UE 115 selects the first cell to camp on and registers with the first cell 105a. In some implementations, the UE 115 may switch RRC modes after camping on the first cell 105a. For example, the UE 115 may switch to an RRC idle state.

At 525, the UE 115 performs a receive level determination. For example, the UE 115 performs a receive level quality based determination. To illustrate, the UE 115 determines an RSRP based metric and uses the RSRP based metric to evaluate cell selection /reselection.

In some implementations, the RSRP based metric is determined based on RSRP and corresponds to a receive level quality metric. In a particular implementation, the threshold is low quality threshold for the first cell 105a (e.g., threshlowpower) , and the RSRP based metric (e.g., Srxlev) is compared to the low quality threshold for the first cell 105a. To illustrate, the Srxlev is compared to the low quality threshold for the serving cell.

Additionally, or alternatively, the UE 115 performs an SNR based determination. For example, the UE 115 determines an SNR value for the first cell 105a, and compares the SNR value to the first threshold or a second threshold. To illustrate, the SNR of the first cell 105a is compared to a threshold value of 10 dB to determine if the SNR is less than the second threshold. In response to satisfying the SNR based determination, the UE 115 may select another cell. When the SNR based determination is used in addition to the receive level based determination, the UE 115 may determine to select another cell based on satisfying a condition associated with either the receive level determination or the SNR determination, in some implementations. In some other implementations, the UE 115 may determine to select another cell based on satisfying conditions for both determinations.

At 530, the UE 115 selects the second cell 105b to camp on and registers with the second cell 105b in response to the receive level determination or determinations. For example, the UE 115 may select a particular cell who satisfies a non-serving cell based condition.

At 535, the UE 115 performs a RAT timer determination. For example, the UE 115 initiates a timer in response to camping on the second cell 105b. In response to expiration of the timer, the UE proceeds to cell selection operations, such as cell reversion.

At 540, the UE 115 selects the first cell 105a to camp on and registers with the first cell 105a in response to the RAT timer determination. For example, the UE 115 may automatically select the first cell 105a in response to the timer expiring. In another example, the UE 115 may perform a cell selection operation /determination in response to the timer expiring. In such implementations, the UE 115 selects a particular cell that satisfies a condition and such cell may or may not be the first cell 105a that was previously camped on.

Thus, in the example in FIG. 5, the UE 115 may stay on the first cell 105a longer, as compared to FIG. 3. As compared to FIG. 3, in FIG. 5 the UE 115 may not bounce between cells as much.

Referring to FIG. 6, FIG. 6 is a diagram of an example of a ladder diagram 600 with a receive level determination and a quality level determination for cell selection. Said another way, multiple types of determinations can be used for selection. As illustrated in the example of FIG. 6, the ladder diagram 600 illustrates a UE 115, a first cell 105a, and a second cell 105b.

At 610, the UE 115 selects the first cell 105a to camp on and registers with the first cell 105a. At 615, the UE 115 performs a receive level determination. For example, the UE 115 performs a receive level determination similar to as described with reference to 525 of FIG. 5. In a particular implementation, the UE 115 determines if a RSRP metric, Srxlev, of the first cell 105a is less than a low power threshold, thresh_lowp, of the first cell 105a. Additionally, the UE 115 determines if a SNR of the first cell 105a is less than a general SNR, such as 10 dB, in some such implementations. In response to satisfying either determination, the UE 115 may proceed to performing a reselection process, such as by evaluating an quality level based condition.

At 620, the UE 115 performs a quality level determination. For example, the UE 115 performs a quality level determination similar to as described with reference to FIG. 3. As shown in the example of FIG. 6, the quality level determination is performed based on /dependent on the receive level determination being satisfied. Such a gatekeeping process to conventional reselection operations may improve cell attachment and reduce cell switching, such as bouncing back and forth between cells.

At 625, the UE 115 selects the second cell 105b to camp on and registers with the second cell 105b in response to satisfying the quality level determination condition, which was performed in response to satisfying the receive level determination condition.

At 630, the UE 115 performs a RAT timer determination, similar to as described with reference to 535 of FIG. 5. For example, the UE 115 initiates a timer in response to camping on the second cell 105b. In response to expiration of the timer, the UE proceeds to cell selection operations, such as cell reversion. At 635, the UE 115 selects the first cell 105a to camp on and registers with the first cell 105a in response to the RAT timer determination.

Thus, in the example in FIG. 6, the UE 115 uses multiple (e.g. two) types of determinations for initiating cell selection (e.g., deciding when to switch) . Said another way, another determination or determinations may be used in addition to conventional /quality level determinations for cell selection /reselection. Although the determinations are illustrated serially in FIG. 6, in other implementations the determinations may be performed in parallel. As compared to the ladder diagram 500 of FIG. 5, the ladder diagram 600 of FIG. 6 uses more determinations before initiating conventional selection operations and selecting a lower priority cell. Thus, a UE may spend more time on the higher priority cell.

A particular UE may be set to operate in one mode depending on hardware capabilities or may switch between the modes of FIGS. 3, 5, and/or 6 based on one or more received message, conditions, and/or inputs.

FIG. 7 is a flow diagram illustrating example blocks executed by a UE configured according to an aspect of the present disclosure. The example blocks will also be described with respect to UE 115 as illustrated in FIG. 9. FIG. 9 is a block diagram illustrating UE 115 configured according to one aspect of the present disclosure. UE 115 includes the structure, hardware, and components as illustrated for UE 115 of FIG. 2. For example, UE 115 includes controller/processor 280, which operates to execute logic or computer instructions stored in memory 282, as well as controlling the components of UE 115 that provide the features and functionality of UE 115. UE 115, under control of controller/processor 280, transmits and receives signals via wireless radios 900a-r and antennas 252a-r. Wireless radios 900a-r includes various components and hardware, as illustrated in FIG. 2 for UE 115, including modulator/demodulators 254a-r, MIMO detector 256, receive processor 258, transmit processor 264, and TX MIMO processor 266. As illustrated in the example of FIG. 9, memory 282 stores Measurement Logic 902, Cell Selection logic 903 (e.g., reselection logic) , RSRP data 904, RSRQ data 905, thresholds data 906, and settings data 907.

At block 700, a wireless communication device, such as a UE, establishes a first connection to a first cell, wherein the UE is operating in Evolved Universal Terrestrial Radio Access (E-UTRA) New Radio (NR) dual connectivity (ENDC) mode. For example, a UE, such as UE 115, establishes a communication link with a base station, such as base station 105, by conventional operations. To illustrate, the base station 105 may transmit a SSB burst set and the UE 115 may transmit a request to join.

At block 701, the UE 115 determines a channel quality associated with the first cell based on one or more reference signals received from the first cell. For example, the UE 115 determines a receive level quality value, such as RSRP, SNR, or both, based on reference signals from the base station 105, as described with reference to FIGS. 4-6.

At block 702, the UE 115 determines whether the channel quality is less than a threshold. For example, the UE 115 performs an RSRP determination, a SNR determination, or both, based on the threshold parameter of low quality, as described with reference to FIGS. 4-6, while being in an RRC idle state.

At block 703, the UE 115 determines whether a cell reselection condition is satisfied in response to the channel quality being less than the threshold. For example, the UE 115 performs receive level based channel reselection operations in response to the channel quality determination being satisfied, as described with reference to FIGS. 3, 4, and 6.

At block 704, the UE 115 establishes a second connection to a second cell in response to the cell reselection condition being satisfied, wherein the second cell is one of a Universal Mobile Telecommunications System (UMTS) cell or a Global Systems for Mobile (GSM) cell. For example, the UE 115 determines to move to second cell (e.g., non-serving cell) based on a RSRQ metric /determination, as described with reference to FIGS. 3-6. To illustrate, the UE 115 determines to move to the second cell responsive to satisfying a condition that an Squal of the first cell is less than the threshold and that an Squal of the second cell is greater than a second threshold.

The UE 115 may execute additional blocks (or the UE 115 may be configured further perform additional operations) in other implementations. For example, the UE 115 may perform one or more operations described above or in the claims.

Accordingly, a UE and a base station may perform enhanced cell selection operations. By performing cell selection operations, throughput and reliability may be increased.

FIG. 8 is a flow diagram illustrating another example of blocks executed by a UE configured according to an aspect of the present disclosure. The example blocks will also be described with respect to UE 115 as illustrated in FIG. 9, described above.

At block 800, a wireless communication device, such as a UE, establishes a communication link with a network entity. For example, a UE, such as UE 115, establishes a communication link with a base station, such as base station 105, by conventional operations. To illustrate, the base station 105 may transmit a SSB burst set and the UE 115 may transmit a request to join.

At block 801, the UE 115 receives a threshold parameter associated with cell reselection for the network entity. For example, the UE 115 receives a low power threshold parameter of a low quality threshold parameter for the cell (e.g., serving cell) , as described with reference to FIGS. 3-6.

At block 802, the UE 115 performs an RSRP determination based on the threshold parameter associated with cell reselection. For example, the UE 115 performs an RSRP determination based on the threshold parameter of low power or quality, as described with reference to FIGS. 4-6, while being in an RRC idle state.

At block 803, the UE 115 performs an SNR determination based on a second threshold parameter. For example, the UE 115 performs an SNR determination based on a second threshold parameter, as described with reference to FIGS. 4-6. The second threshold parameter may be the same as or different from the first parameter. To illustrate, the SNR determination may be based on the same threshold as the RSRP determination, i.e., a first threshold (e.g., threshold parameter of low quality) or a different threshold (i.e., a second threshold) .

At block 804, the UE 115 determines whether to move to another cell based on the RSRP determination and the SNR determination. For example, the UE 115 determines whether to move to second cell (e.g., non-serving cell) based on the RSRP determination or the SNR determination, as described with reference to FIGS. 4-6. To illustrate, the UE 115 determines to move to the second cell responsive to satisfying a condition for either the RSRP determination or the SNR determination.

Accordingly, a UE and a base station may perform enhanced cell selection operations. By performing cell selection operations, throughput and reliability may be increased

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The functional blocks and modules described herein (e.g., the functional blocks and modules in FIG. 2) may comprise processors, electronics devices, hardware devices, electronics components, logical circuits, memories, software codes, firmware codes, etc., or any combination thereof. In addition, features discussed herein relating to improved cell selection may be implemented via specialized processor circuitry, via executable instructions, and/or combinations thereof.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps (e.g., the logical blocks in FIGS. 7 and 8 described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure. Skilled artisans will also readily recognize that the order or combination of components, methods, or interactions that are described herein are merely examples and that the components, methods, or interactions of the various aspects of the present disclosure may be combined or performed in ways other than those illustrated and described herein.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein may be implemented or performed with 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, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the disclosure herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

In one or more exemplary designs, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. Computer-readable storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, a connection may be 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, or digital subscriber line (DSL) , then the coaxial cable, fiber optic cable, twisted pair, or DSL, are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , hard disk, solid state disk, and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

As used herein, including in the claims, the term “and/or, ” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) or any of these in any combination thereof.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

A method of wireless communication by a user equipment (UE) in a network, comprising:

establishing a first connection to a first cell, wherein the UE is operating in Evolved Universal Terrestrial Radio Access (E-UTRA) New Radio (NR) dual connectivity (ENDC) mode;

determining a channel quality associated with the first cell based on one or more reference signals received from the first cell;

determining whether the channel quality is less than a threshold;

determining whether a cell reselection condition is satisfied in response to the channel quality being less than the threshold; and

establishing a second connection to a second cell in response to the cell reselection condition being satisfied, wherein the second cell is one of a Universal Mobile Telecommunications System (UMTS) cell or a Global Systems for Mobile (GSM) cell.
The method of claim 1, further comprising:

establishing a third connection to the first cell;

determining a second channel quality associated with the first cell based on one or more second reference signals;

determining whether the second channel quality is less than the threshold; and

maintaining the third connection to the first cell in response to the second channel quality being greater than or equal to the threshold.
The method of claim 1, further comprising:

establishing a third connection to the first cell;

determining a second channel quality associated with the first cell based on one or more second reference signals;

determining whether the second channel quality is less than the threshold;

determining whether the cell reselection condition is satisfied in response to the second channel quality being less than the threshold; and

maintaining the third connection to the first cell in response to the cell reselection condition being not satisfied.
The method of claim 1, wherein:

the channel quality comprises a reference signal received power (RSRP) or a signal to noise ratio (SNR) .
The method of claim 4, wherein determining whether the channel quality is lower than the threshold comprises:

determining whether the RSRP is less than a low power threshold for the first cell.
The method of claim 4, wherein determining whether the channel quality is lower than the threshold comprises:

determining whether the SNR is less than a SNR threshold for the first cell.
The method of claim 1, wherein the UE is in a RRC Idle state prior to determining whether the channel quality is less than a threshold.
The method of claim 7, further comprising:

prior to receiving the one or more reference signals from the first cell, releasing an RRC connection from the first cell.
An apparatus for wireless communication, the apparatus comprising:

means for establishing a first connection to a first cell by a user equipment (UE) , wherein the UE is operating in Evolved Universal Terrestrial Radio Access (E-UTRA) New Radio (NR) dual connectivity (ENDC) mode;

means for determining a channel quality associated with the first cell based on one or more reference signals received from the first cell;

means for determining whether the channel quality is less than a threshold;

means for determining whether a cell reselection condition is satisfied in response to the channel quality being less than the threshold; and

means for establishing a second connection to a second cell in response to the cell reselection condition being satisfied, wherein the second cell is one of a Universal Mobile Telecommunications System (UMTS) cell or a Global Systems for Mobile (GSM) cell.
The apparatus of claim 9, further comprising:

means for establishing a third connection to the first cell;

means for determining a second channel quality associated with the first cell based on one or more second reference signals;

means for determining whether the second channel quality is less than the threshold; and

means for maintaining the third connection to the first cell in response to the second channel quality being greater than or equal to the threshold.
The apparatus of claim 9, further comprising:

means for establishing a third connection to the first cell;

means for determining a second channel quality associated with the first cell based on one or more second reference signals;

means for determining whether the second channel quality is less than the threshold;

means for determining whether the cell reselection condition is satisfied in response to the second channel quality being less than the threshold; and

means for maintaining the third connection to the first cell in response to the cell reselection condition being not satisfied.
The apparatus of claim 9, wherein:

the channel quality comprises a reference signal received power (RSRP) or a signal to noise ratio (SNR) .
The apparatus of claim 12, wherein determining whether the channel quality is lower than the threshold comprises:

determining whether the RSRP is less than a low power threshold for the first cell.
The apparatus of claim 12, wherein determining whether the channel quality is lower than the threshold comprises:

determining whether the SNR is less than a SNR threshold for the first cell.
The apparatus of claim 9, wherein the UE is in a RRC Idle state prior to determining whether the channel quality is less than a threshold.
The apparatus of claim 15, further comprising:

prior to receiving the one or more reference signals from the first cell, releasing an RRC connection from the first cell.
A non-transitory computer-readable medium having program code recorded thereon, the program code comprising:

program code executable by a computer for causing the computer to establish a first connection to a first cell by a user equipment (UE) , wherein the UE is operating in Evolved Universal Terrestrial Radio Access (E-UTRA) New Radio (NR) dual connectivity (ENDC) mode;

program code executable by a computer for causing the computer to determine a channel quality associated with the first cell based on one or more reference signals received from the first cell;

program code executable by a computer for causing the computer to determine whether the channel quality is less than a threshold;

program code executable by a computer for causing the computer to determine whether a cell reselection condition is satisfied in response to the channel quality being less than the threshold; and

program code executable by a computer for causing the computer to establish a second connection to a second cell in response to the cell reselection condition being satisfied, wherein the second cell is one of a Universal Mobile Telecommunications System (UMTS) cell or a Global Systems for Mobile (GSM) cell.
The transitory computer-readable medium of claim 17, further comprising:

program code executable by a computer for causing the computer to establish a third connection to the first cell;

program code executable by a computer for causing the computer to determine a second channel quality associated with the first cell based on one or more second reference signals;

program code executable by a computer for causing the computer to determine whether the second channel quality is less than the threshold; and

program code executable by a computer for causing the computer to maintain the third connection to the first cell in response to the second channel quality being greater than or equal to the threshold.
The transitory computer-readable medium of claim 17, further comprising:

program code executable by a computer for causing the computer to establish a third connection to the first cell;

program code executable by a computer for causing the computer to determine a second channel quality associated with the first cell based on one or more second reference signals;

program code executable by a computer for causing the computer to determine whether the second channel quality is less than the threshold;

program code executable by a computer for causing the computer to determine whether the cell reselection condition is satisfied in response to the second channel quality being less than the threshold; and

program code executable by a computer for causing the computer to maintain the third connection to the first cell in response to the cell reselection condition being not satisfied.
The transitory computer-readable medium of claim 17, wherein:

the channel quality comprises a reference signal received power (RSRP) or a signal to noise ratio (SNR) .
The transitory computer-readable medium of claim 20, wherein determining whether the channel quality is lower than the threshold comprises:

determining whether the RSRP is less than a low power threshold for the first cell.
The transitory computer-readable medium of claim 20, wherein determining whether the channel quality is lower than the threshold comprises:

determining whether the SNR is less than a SNR threshold for the first cell.
The transitory computer-readable medium of claim 17, wherein the UE is in a RRC Idle state prior to determining whether the channel quality is less than a threshold.
The transitory computer-readable medium of claim 23, further comprising:

prior to receiving the one or more reference signals from the first cell, releasing an RRC connection from the first cell.
An apparatus for wireless communication, the apparatus comprising:

establishing a first connection to a first cell by a user equipment (UE) , wherein the UE is operating in Evolved Universal Terrestrial Radio Access (E-UTRA) New Radio (NR) dual connectivity (ENDC) mode;

determining a channel quality associated with the first cell based on one or more reference signals received from the first cell;

determining whether the channel quality is less than a threshold;

determining whether a cell reselection condition is satisfied in response to the channel quality being less than the threshold; and

establishing a second connection to a second cell in response to the cell reselection condition being satisfied, wherein the second cell is one of a Universal Mobile Telecommunications System (UMTS) cell or a Global Systems for Mobile (GSM) cell.
The apparatus of claim 25, further comprising:

establishing a third connection to the first cell;

determining a second channel quality associated with the first cell based on one or more second reference signals;

determining whether the second channel quality is less than the threshold; and

maintaining the third connection to the first cell in response to the second channel quality being greater than or equal to the threshold.
The apparatus of claim 25, further comprising:

establishing a third connection to the first cell;

determining a second channel quality associated with the first cell based on one or more second reference signals;

determining whether the second channel quality is less than the threshold;

determining whether the cell reselection condition is satisfied in response to the second channel quality being less than the threshold; and

maintaining the third connection to the first cell in response to the cell reselection condition being not satisfied.
The apparatus of claim 25, wherein:

the channel quality comprises a reference signal received power (RSRP) or a signal-to-noise ratio (SNR) .
The apparatus of claim 28, wherein determining whether the channel quality is lower than the threshold comprises:

determining whether the RSRP is less than a low power threshold for the first cell.
The apparatus of claim 28, wherein determining whether the channel quality is lower than the threshold comprises:

determining whether the SNR is less than a SNR threshold for the first cell.
The apparatus of claim 25, wherein the UE is in a Radio Resource Control (RRC) Idle state prior to determining whether the channel quality is less than a threshold.
The apparatus of claim 31, further comprising:

prior to receiving the one or more reference signals from the first cell, releasing a Radio Resource Control (RRC) connection from the first cell.
A method of wireless communication comprising:

establishing, by a user equipment (UE) , a communication link with a network entity;

receiving, by the UE, a threshold parameter associated with cell reselection for the network entity;

performing, by the UE, a reference signal received power (RSRP) determination based on the threshold parameter;

performing, by the UE, a signal-to-noise ratio (SNR) determination based on a second threshold parameter; and

determining, by the UE while in an RRC idle state, whether to move to another cell based on the RSRP determination and the SNR determination.
The method of claim 33, wherein performing the RSRP determination includes comparing an RSRP metric value to the threshold parameter, and further comprising:

moving, by the UE, to a second network entity in response to determining that the RSRP metric value is less than the threshold parameter.
The method of claim 33, wherein performing the SNR determination includes comparing an SNR value to the second threshold parameter, and further comprising:

moving, by the UE, to a second network entity in response to determining that the SNR value is less than the second threshold parameter.
The method of claim 33, further comprising:

moving, by the UE, to a second network entity in response to determining that an RSRP metric value is less than the threshold parameter and in response to determining that an SNR value is less than the second threshold parameter.
The method of claim 33, wherein the network entity is a LTE anchor cell.
The method of claim 33, wherein the other cell is a 2G or 3G network cell.
The method of claim 33, wherein the UE is also connected to a third network entity in a E-UTRAN New Radio –Dual Connectivity (ENDC) mode, and wherein the third network entity is a 5G network cell.
The method of claim 33, wherein the threshold parameter is included in a system information block (SIB) message.
The method of claim 40, wherein the SIB message comprises a SIB3 message, and wherein the threshold parameter is threshServingLowP.
The method of claim 33, further comprising:

performing, by the UE, a reference signal received quality (RSRQ) determination based on a threshold parameter of low quality, wherein determining whether to move to the other cell is further based on the RSRQ determination.
The method of claim 42, wherein the RSRQ determination is performed in response to:

determining that an RSRP metric value is less than the threshold parameter of low quality; or

determining that an SNR value is less than the second threshold parameter.
The method of claim 42, wherein performing the RSRQ determination includes comparing multiple RSRQ metric values to the threshold parameter of low quality, and further comprising:

moving, by the UE, to a second network entity in response to determining that a first RSRQ metric value is less than the threshold parameter of low quality and in response to determining that a second RSRQ metric value is greater than the threshold parameter of low quality.
The method of claim 44, wherein the first RSRQ metric value is a quality value of a serving cell, and wherein the second RSRQ metric value is a quality value of a non-serving cell.
The method of claim 42, wherein the RSRQ determination is performed for a time period corresponding to a Radio Access Technology (RAT) selection time interval (Treselection _RAT) .
The method of claim 33, further comprising:

moving, by the UE, to a second network entity based on the RSRP determination and the SNR determination;

initiating, by the UE, a high priority Radio Access Technology (RAT) search timer in response to moving to the second network entity; and

moving, by the UE, to the network entity in response to expiration of the high priority RAT search timer.
The method of claim 47, wherein moving to the second network entity is performed in response to:

determining that a first RSRQ metric value is less than a threshold parameter of low quality; and

determining that a second RSRQ metric value is greater than the threshold parameter of low quality.
The method of claim 47, wherein moving to the second network entity includes performing, by the UE, an IRAT to GSM handover.
The method of claim 33, further comprising:

moving, by the UE, to a second network entity based on the RSRP determination and the SNR determination;

initiating, by the UE, high priority RAT search timer in response to moving to the second network entity; and

staying, by the UE, camped on the second network entity in response to exiting an E-UTRAN New Radio –Dual Connectivity (ENDC) mode.
The method of claim 33, wherein performing the RSRP determination includes comparing a cell selection receive level value (Srxlev) to the threshold parameter of low power.
The method of claim 51, wherein the cell selection receive level value (Srxlev) is determined based on a measured cell receive level value (Qrxlevmeas) , a minimum required receive level in the cell (Qrxlevmin) , a receive level offset value (Qrxlevminoffset) , a power compensation value (Pcompensation) , or a combination thereof.
The method of claim 52, wherein the power compensation value (Pcompensation) is determined based on a maximum RF output power of the UE according to a UE power class (PPowerClass) .
The method of claim 33, wherein the RSRP determination and SNR determination are performed prior to performing an IRAT TO GSM cell selection process.
The method of claim 33, further comprising, prior to performing the RSRP determination, transmitting, by the UE, a capabilities message indicating that the UE is configured for RSRP based cell selection.
The method of claim 33, further comprising, prior to performing the RSRP determination, transmitting, by the UE, a capabilities message indicating that the UE is a RSRP based cell selection capable UE.
The method of claim 33, further comprising, prior to performing the RSRP determination, receiving, by the UE, a configuration message from a networking entity indicating a RSRP based cell selection mode.
A method of wireless communication comprising:

establishing, by a user equipment (UE) , acommunication link with a network entity;

receiving, by the UE, a threshold parameter of channel quality for the network entity;

performing, by the UE, a receive level determination based on the threshold parameter of channel quality;

performing, by the UE, a quality level determination based on the threshold parameter of channel quality; and

determining, by the UE while in an RRC idle state, whether to move to another cell based on the receive level determination and the quality level determination.