WO2021237571A1

WO2021237571A1 - Method and apparatus for managing wireless communication

Info

Publication number: WO2021237571A1
Application number: PCT/CN2020/092925
Authority: WO
Inventors: Hao Zhang; Tianya LIN; Jie Hong
Original assignee: Qualcomm Incorporated
Priority date: 2020-05-28
Filing date: 2020-05-28
Publication date: 2021-12-02
Also published as: WO2021237571A9

Abstract

The apparatus of wireless communication may be a UE to handle being camped on a marginal cell without handover instruction from base station. The UE may locally release an RRC connection with a first base station based on at least one of an SNR, a SINR, or a BLER from the first base station and reselect to a second base station different than the first base station upon locally releasing the RRC connection with the first base station.

Description

METHOD AND APPARATUS FOR MANAGING WIRELESS COMMUNICATION

BACKGROUND

Technical Field

The present disclosure relates generally to communication systems, and more particularly, to management of a marginal connection with a base station by a user equipment (UE) .

Introduction

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR) . 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT) ) , and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB) , massive machine type communications (mMTC) , and ultra-reliable low latency communications (URLLC) . Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

SUMMARY

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

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a user equipment. The UE may be in an RRC connected mode with a cell of a first base station. The UE may locally release the RRC connection with the first base station based on at least one of a signal to noise ratio (SNR) , a signal to interference plus noise ratio (SINR) , or a block error rate (BLER) from the first base station, and reselect to a second base station. In one aspect, the UE may initiate a local release of the RRC connection upon determining that at least one of a second reference signal received power (RSRP) or a second reference signal received quality (RSRQ) of the second base station is greater than a first RSRP or a first RSRQ of the first base station. Also, the UE may locally release the RRC connection upon determining that at least one of the SNR from the first base station is less than an SNR threshold, the SINR from the first base station is less than a SINR threshold, or the BLER from the first base station is greater than a BLER threshold for a time period greater than a time threshold.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.

FIGs. 2A, 2B, 2C, and 2D are diagrams illustrating examples of a first 5G/NR frame, DL channels within a 5G/NR subframe, a second 5G/NR frame, and UL channels within a 5G/NR subframe, respectively.

FIG. 3 is a diagram illustrating an example of a base station and user equipment (UE) in an access network.

FIG. 4 is a call flow diagram illustrating a method of wireless communication.

FIG. 5 is a flowchart of a method of wireless communication.

FIG. 6 is a diagram illustrating an example of a hardware implementation for an example apparatus.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements” ) . These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs) , central processing units (CPUs) , application processors, digital signal processors (DSPs) , reduced instruction set computing (RISC) processors, systems on a chip (SoC) , baseband processors, field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN) ) includes base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and another core network 190 (e.g., a 5G Core (5GC) ) . The base stations 102 may include macrocells (high power cellular base station) and/or small cells (low power cellular base station) . The macrocells include base stations. The small cells include femtocells, picocells, and microcells.

The base stations 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) may interface with the EPC 160 through first backhaul links 132 (e.g., S1 interface) . The base stations 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN) ) may interface with core network 190 through second backhaul links 184. In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160 or core network 190) with each other over third backhaul links 134 (e.g., X2 interface) . The first backhaul links 132, the second backhaul links 184, and the third backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102' may have a coverage area 110' that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) . The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102 /UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL) . The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .

Certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152 /AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

The small cell 102' may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102' may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102', employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.

A base station 102, whether a small cell 102' or a large cell (e.g., macro base station) , may include and/or be referred to as an eNB, gNodeB (gNB) , or another type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies, and/or near mmW frequencies in communication with the UE 104. When the gNB 180 operates in mmW or near mmW frequencies, the gNB 180 may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Frequency range bands include frequency range 1 (FR1) , which includes frequency bands below 7.225 GHz, and frequency range 2 (FR2) , which includes frequency bands above 24.250 GHz. Communications using the mmW /near mmW radio frequency (RF) band (e.g., 3 GHz –300 GHz) has extremely high path loss and a short range. Base stations /UEs may operate within one or more frequency range bands. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range. The base station 180 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming.

The base station 180 may transmit a beamformed signal to the UE 104 in one or more transmit directions 182'. The UE 104 may receive the beamformed signal from the base station 180 in one or more receive directions 182”. The UE 104 may also transmit a beamformed signal to the base station 180 in one or more transmit directions. The base station 180 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 180 /UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180 /UE 104. The transmit and receive directions for the base station 180 may or may not be the same. The transmit and receive directions for the UE 104 may or may not be the same.

The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

The core network 190 may include a Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196. The AMF 192 is the control node that processes the signaling between the UEs 104 and the core network 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF 195. The UPF 195 provides UE IP address allocation as well as other functions. The UPF 195 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a Packet Switch (PS) Streaming (PSS) Service, and/or other IP services.

The base station may include and/or be referred to as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a transmit reception point (TRP) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or core network 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) . The UE 104 may also be referred to as a station, a mobile station, 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, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

Referring again to FIG. 1, in certain aspects, the UE 104 may be configured to manage a connection between the UE 104 and a base station 102/180 when the UE 104 is camped on the base station 102/180. The connection may be with a cell or may be a beam formed signal that has a marginal connection quality. The UE may initiate a handover to another base station without receiving a handover instruction from the base station 102/180 (198) . Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

FIG. 2A is a diagram 200 illustrating an example of a first subframe within a 5G/NR frame structure. FIG. 2B is a diagram 230 illustrating an example of DL channels within a 5G/NR subframe. FIG. 2C is a diagram 250 illustrating an example of a second subframe within a 5G/NR frame structure. FIG. 2D is a diagram 280 illustrating an example of UL channels within a 5G/NR subframe. The 5G/NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for either DL or UL, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by FIGs. 2A, 2C, the 5G/NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL) , where D is DL, U is UL, and F is flexible for use between DL/UL, and subframe 3 being configured with slot format 34 (with mostly UL) . While

subframes

3, 4 are shown with slot formats 34, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI) , or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI) . Note that the description infra applies also to a 5G/NR frame structure that is TDD.

Other wireless communication technologies may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms) . Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. The symbols on DL may be cyclic prefix (CP) OFDM (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission) . The number of slots within a subframe is based on the slot configuration and the numerology. For slot configuration 0, different numerologies μ 0 to 4 allow for 1, 2, 4, 8, and 16 slots, respectively, per subframe. For slot configuration 1, different numerologies 0 to 2 allow for 2, 4, and 8 slots, respectively, per subframe. Accordingly, for slot configuration 0 and numerology μ, there are 14 symbols/slot and 2 ^μ slots/subframe. The subcarrier spacing and symbol length/duration are a function of the numerology. The subcarrier spacing may be equal to 2 ^μ*15 kHz, where μ is the numerology 0 to 4. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=4 has a subcarrier spacing of 240 kHz. The symbol length/duration is inversely related to the subcarrier spacing. FIGs. 2A-2D provide an example of slot configuration 0 with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (see FIG. 2B) that are frequency division multiplexed. Each BWP may have a particular numerology.

A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs) ) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs) . The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include demodulation RS (DM-RS) (indicated as R _x for one particular configuration, where 100x is the port number, but other DM-RS configurations are possible) and channel state information reference signals (CSI- RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS) , beam refinement RS (BRRS) , and phase tracking RS (PT-RS) .

FIG. 2B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) , each CCE including nine RE groups (REGs) , each REG including four consecutive REs in an OFDM symbol. A PDCCH within one BWP may be referred to as a control resource set (CORESET) . Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE 104 to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI) . Based on the PCI, the UE can determine the locations of the aforementioned DM-RS. The physical broadcast channel (PBCH) , which carries a master information block (MIB) , may be logically grouped with the PSS and SSS to form a synchronization signal (SS) /PBCH block (also referred to as SS block (SSB) ) . The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN) . The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs) , and paging messages.

As illustrated in FIG. 2C, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH) . The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS) . The SRS may be transmitted in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

FIG. 2D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI) , such as scheduling requests, a channel quality indicator (CQI) , a precoding matrix indicator (PMI) , a rank indicator (RI) , and hybrid automatic repeat request (HARQ) ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR) , a power headroom report (PHR) , and/or UCI.

FIG. 3 is a block diagram of a base station 310 in communication with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller/processor 375. The controller/processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs) , RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release) , inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression /decompression, security (ciphering, deciphering, integrity protection, integrity verification) , and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs) , error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs) , re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs) , demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK) , quadrature phase-shift keying (QPSK) , M-phase-shift keying (M-PSK) , M-quadrature amplitude modulation (M-QAM) ) . The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a respective spatial stream for transmission.

At the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT) . The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller/processor 359, which implements layer 3 and layer 2 functionality.

The controller/processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller/processor 359 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

Similar to the functionality described in connection with the DL transmission by the base station 310, the controller/processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression /decompression, and security (ciphering, deciphering, integrity protection, integrity verification) ; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the base station 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

The controller/processor 375 can be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. IP packets from the controller/processor 375 may be provided to the EPC 160. The controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

At least one of the TX processor 368, the RX processor 356, and the controller/processor 359 may be configured to perform aspects in connection with 198 of FIG. 1.

The UE 104 may be in an RRC connected mode with a base station 102/180. That is, the UE 104 may have established an RRC connection with the base station 102/180. The UE 104 may periodically /semi-statically measure and analyze a serving cell (LTE) /a beam formed signal (5G/NR) from the base station 102/180, as well as a neighbor cell (LTE) /a beam formed signal (5G/NR) from a neighbor base station neighboring the base station 102/180, and report the measurements in a measurement report to the base station 102/180. For example, the UE 104 may submit a channel state information (CSI) report to the base station 102/180. The base station 102/180 may analyze the measurement report received from the UE 104. The base station 102/180 may determine that UE 104 would have an improved connection with the neighbor base station and may handover the UE 104 to to the neighbor base station. That is, the base station 102/180 may transmit an RRC reconfiguration message to the UE 104, instructing the UE to transmit an RRC connection request to the neighbor base station.

For example, the UE 104 may not be able to maintain a stable data transmission for transfer data when a block error rate (BLER) of the connection with the base station 102/180 is high (e.g., over 15%) or a signal to noise ratio (SNR) of the commotion with the base station 102/180 is marginal (e.g., less than 10 dB) . The connection may be with the corresponding cell (LTE) or may be the beam formed signal (5G/NR) . Further for 5G/NR, the UE 104 may not maintain a stable data transmission when a signal to interference plus noise ratio (SINR) of the beam formed signal from the base station 102/180 is of low quality (e.g., less than 10 dB) . When the UE 104 is in such a state, the NW may be configured to trigger the handover of the UE 104 from the base station to another base station with a cell or a beam formed signal of increased quality.

However, under certain scenarios, the base station 102/180 may fail to recognize the situation of the UE 104 and instruct the handover of the UE 104 from the base station 102/180 to a neighbor base station in a timely fashion. The UE 104 may keep sending the measurement report to the base station 102/180 and wait for the base station 102/180 to initiate the handover to the neighbor base station. When the UE 104 remains camped on the cell/base station 102/180 with a bad connection, the user experience may be unacceptable for services that require a consistent data transmission with reduced network latency (e.g., a gaming service) .

FIG. 4 is a call flow diagram 400 illustrating a method of wireless communication.

The UE 402 may be in RRC connected mode 408 with the first base station 404. That is, the UE 402 may have established an RRC connection 408 with the first base station 404. The UE 402 may periodically /semi-statically measure and analyze a serving cell (LTE) /a beam formed signal (5G/NR) 410 from the first base station 404, as well as measure /analyze a neighbor cell (LTE) /a beam formed signal (5G/NR) 412 from a second base station 406 neighboring the first base station 404, and report the measurements in a measurement report 414 (e.g., CSI report) to the first base station 404.

The UE 402 may initiate a local release of the RRC connection with the first base station upon determining 416 that the RSRP/RSRQ of the second base station 406 is higher than the RSRP/RSRQ of first base station 404. Here, the UE 402 locally releasing the RRC connection refers to the UE 402 entering the RRC Idle mode. That is, the UE 402 may determine 416 that the RSRP/RSRQ of the neighbor cell (LTE) /the beam formed signal (5G/NR) 412 from the second base station 406 is higher than the RSRP/RSRQ of the serving cell (LTE) /the beam formed signal (5G/NR) 410 from the first base station 404. The UE 402 may initiate the local release of the RRC connection upon determining that the RSRP/RSRQ of the second base station 406 is higher than the RSRP/RSRQ of the first base station 404.

Upon initiating the local release of the RRC connection with the first base station, the UE 402 may determine whether the SNR from the first base station 404 is less than an SNR threshold, the SINR from the first base station 404 is less than a SINR threshold, or the BLER from the first base station 404 is greater than a BLER threshold for a time period greater than a time threshold 418.

That is, upon determining that the SNR from the first base station 404 is less than the SNR threshold, the SINR from the first base station 404 is less than the SINR threshold, or the BLER from the first base station 404 is greater than the BLER threshold, the UE 402 may start a timer and monitor the serving cell (LTE) /the beam formed signal (5G/NR) 410 from the first base station 404. In some aspects, the UE 402 may keep the timer running until a time threshold while the SNR from the first base station 404 is less than the SNR threshold, the SINR from the first base station 404 is less than the SINR threshold, or the BLER from the first base station 404 is greater than the BLER threshold. Upon determining that none of the conditions are met while the timer is running, the UE may terminate the local release of the RRC connection and reset the timer. Should the timer expire while any one of the conditions being met, the UE may locally release the RRC connection and reset the timer.

In some aspects, when the UE 402 determines that the SNR from the first base station 404 is not less than the SNR threshold, the SINR from the first base station 404 is not less than the SINR threshold, and the BLER from the first base station 404 is not greater than the BLER threshold before the timer reaches the time threshold, The UE may determine that the communication between the UE 402 and the first base station 404 is in a good condition. Therefore, the UE 402 may not leave the first base station 404 to attempt to connect to the second base station 406.

Upon determining that the time reaches the time threshold while the SNR from the first base station 404 is less than an SNR threshold, the SINR from the first base station 404 is less than a SINR threshold, or the BLER from the first base station 404 is greater than a BLER threshold, the UE 402 may locally release the RRC connection with the first base station 404 by entering an RRC Idle mode 420.

Upon entering the RRC Idle mode 420, the UE 402 may try to re-establish an RRC connection. Particularly, the UE 402 may select to establish the RRC connection with a base station that has the best RSRP/RSRQ. For example, the UE 402 may determine 416 that the RSRP/RSRQ of the second base station 406 is higher than the RSRP/RSRQ of the first base station 404, the UE 402 may reselect 422 the second base station 406 to request the RRC connection 424 to the second base station 406.

The UE 402 may transmit a service request 424 to the second base station 406, and the UE 402 and the second base station 406 may establish an RRC connection 426 with the second base station to continue the data communication.

FIG. 5 is a flowchart 500 of a method of wireless communication. The method may be performed by a UE (e.g., the UE 104/402; the apparatus 602) . At 502, the UE may have an established RRC connection (408) with a first base station BS1 (e.g., the first base station 404) . For example, 502 may be performed by a RRC connection management component 640 (refer to FIG. 6) .

At 504, the UE may report certain measurements in a measurement report (e.g., CSI report) (414) to the first base station BS1. For example, 504 may be performed by the transmission component 634 (refer to FIG. 6) . The measurements reported may be, not limited to, an RSRP, an RSRQ, an SNR, an SINR, or a BLER from the first base station BS1 and the second base station BS2 (e.g., the second base station 406) .

At 506, the UE may determine whether the RSRP/RSRQ of a second base station BS2 (e.g., the second base station 406) is higher than the RSRP/RSRQ of the first base station BS1. That is, the UE may determine whether the RSRP/RSRQ of the neighbor cell (LTE) /the beam formed signal (5G/NR) from the second base station BS2 is higher than the RSRP/RSRQ of the serving cell (LTE) /the beam formed signal (5G/NR) from the first base station BS1 (416) . The UE, upon determining that the RSRP/RSRQ of the second base station BS2 is higher than the RSRP/RSRQ of the first base station BS1, may initiate a local release of the RRC connection with the first base station BS1. For example, 506 may be performed by the signal measuring component 642 (refer to FIG. 6) . If the condition is not met, the UE may return to the RRC connected more with the first base station BS1

At 508, upon initiating the local release of the RRC connection with the first base station BS1, the UE may determine whether the SNR from the first base station BS1 is less than an SNR threshold, the SINR from the first base station BS1 is less than a SINR threshold, or the BLER from the first base station BS1 is greater than a BLER threshold for a time period greater than a time threshold (418) . For example, 508 may be performed by the signal measuring component 642 and a timer component 644 (refer to FIG. 6) . If the condition is not met, the UE may return to the RRC connected more with the first base station BS1

At 510, the UE, upon determining that the SNR from the first base station BS1 is less than the SNR threshold, the SINR from the first base station BS1 is less than the SINR threshold, and the BLER from the first base station BS1 is greater than the BLER for the time equal to or greater than the time threshold, the UE may locally release the RRC connection with the first base station BS1 by entering an RRC Idle mode (420) . For example, 510 may be performed by the RRC connection management component 640 (refer to FIG. 6) .

At 512, the UE may reselect to the second base station BS2 (422) to re-establish the RRC connection with the network via the second base station. At 514, the UE 402 may transmit a service request (424) to the second base station BS2. At 516, the UE and the second base station BS2 may re-establish an RRC connection (426) to continue the data communication. For example, 512, 514, and 516 may be performed by the RRC connection management component 640 and the transmission component 634 (refer to FIG. 6) .

FIG. 6 is a diagram 600 illustrating an example of a hardware implementation for an apparatus 602. The apparatus 602 is a UE and includes a cellular baseband processor 604 (also referred to as a modem) coupled to a cellular RF transceiver 622 and one or more subscriber identity modules (SIM) cards 620, an application processor 606 coupled to a secure digital (SD) card 608 and a screen 610, a Bluetooth module 612, a wireless local area network (WLAN) module 614, a Global Positioning System (GPS) module 616, and a power supply 618. The cellular baseband processor 604 communicates through the cellular RF transceiver 622 with the UE 104 and/or BS 102/180. The cellular baseband processor 604 may include a computer-readable medium /memory. The cellular baseband processor 604 is responsible for general processing, including the execution of software stored on the computer-readable medium /memory. The software, when executed by the cellular baseband processor 604, causes the cellular baseband processor 604 to perform the various functions described supra. The computer-readable medium /memory may also be used for storing data that is manipulated by the cellular baseband processor 604 when executing software. The cellular baseband processor 604 further includes a reception component 630, a communication manager 632, and a transmission component 634. The communication manager 632 includes the one or more illustrated components. The components within the communication manager 632 may be stored in the computer-readable medium /memory and/or configured as hardware within the cellular baseband processor 604. The cellular baseband processor 604 may be a component of the UE 350 and may include the memory 360 and/or at least one of the TX processor 368, the RX processor 356, and the controller/processor 359. In one configuration, the apparatus 602 may be a modem chip and include just the baseband processor 604. In another configuration, the apparatus 602 may be the entire UE (e.g., see 350 of FIG. 3) and include the aforediscussed additional modules of the apparatus 602.

The communication manager 632 includes an RRC connection management component 640 that is configured to locally release the RRC connection with a first base station by entering RRC Idle mode, selecting a second base station, and re-establishing RRC connection with the second base station, e.g., as described in connection with

operations

502, 510, 512, 514, and 516. The communication manager 632 further includes a signal measuring component 642 that is configured to measure cells (LTE) /beam formed signals (5G/NR) from base stations and generate measurement reports, e.g., as described in connection with

operations

504, 506, and 508. The communication manager 632 further includes a timer component 644 that is configured to determine whether a time of a timer is equal to or greater than a time threshold, e.g., as described in connection with operation 508. The

components

640, 642, and 644 are configured to communicate with each other.

The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of FIG. 5. As such, each block in the aforementioned flowcharts of FIG. 5 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

In one configuration, the apparatus 602, and in particular the cellular baseband processor 604, includes means for initiating the local release of an RRC connection upon determining that at least one of a second RSRP or a second RSRQ of the second base station is greater than a first RSRP or a first RSRQ of the first base station, means for locally releasing the RRC connection with a first base station based on at least one of an SNR, an SINR, or a BLER from the first base station, means for reselecting to a second base station different than the first base station upon locally releasing the RRC connection with the first base station, and means for sending a measurement report to the first base station indicating that at least one of the RSRP of the second base station is greater than the RSRP of the first base station, or the RSRQ of the second base station is greater than the RSRQ of the first base station. The aforementioned means may be one or more of the aforementioned components of the apparatus 602 configured to perform the functions recited by the aforementioned means. As described supra, the apparatus 602 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359. As such, in one configuration, the aforementioned means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the aforementioned means.

Referring again to FIGs. 4, 5, and 6, a UE may locally release an RRC connection from a first base station and reselect a second base station for RRC connection when the UE fails to receive an instruction from the first base station to handover the UE from the first base station to the second base station. The UE may initiate a local release of the RRC connection upon determining that one of second RSRP and/or RSRQ of the second base station is greater than one of first RSRP and/or RSRQ of the first base station. The UE may, upon initiating the local release of the RRC connection, determine to release the RRC connection when one of an SNR from the first base station is less than an SNR threshold, an SINR from the first base station is less than an SINR threshold, or a BLER from the first base station is greater than a BLER threshold for a time period greater than a time threshold.

In some aspects, the UE may suppress or reduce delay in wireless communication services from the UE camping on a cell or a connection with a base station, when the base station fails to instruct the UE to handover the UE from the base station to another base station.

Further disclosure is included in the Appendix.

It is understood that the specific order or hierarchy of blocks in the processes /flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes /flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Terms such as “if, ” “when, ” and “while” should be interpreted to mean “under the condition that” rather than imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when, ” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module, ” “mechanism, ” “element, ” “device, ” and the like may not be a substitute for the word “means. ” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for. ”

The following examples are illustrative only and may be combined with aspects of other embodiments or teachings described herein, without limitation.

APPENDIX

Method to avoid camp on poor cell which do not trigger HO to better cell

Scenario

UEs may not transfer stable data transmission when BLER is high (e.g., over 15%) or the serving cell’s SNR is poor (e.g., less than 10 dB) . When the UE enter such state, the NW is configured to trigger HO to a better cell. However, but that not always happen even UE report. User experience is bad especially for gaming.

Aspects of the disclosure

a. Serving cell SNR is lower than SNR_Low (e.g. -10 db, configurable )

b. BLER higher than BLER_High (e.g. over 15%, configurable)

c. Last for over T_Poor (e.g. 10s, configurable )

d. There is a neighbor cell RSRP higher than serving cell

Local release RRC connection and reselect to better neighbor cell if meet d &&c && (a | | b)

Effect of the aspects of the disclosure:

The UE may not need to wait for long time for the network to trigger HO the RRC connection to a better cell and suffer poor data transfer

Call Flow

Claims

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

locally releasing a radio resource control (RRC) connection with a first base station based on at least one of a signal to noise ratio (SNR) , a signal to interference plus noise ratio (SINR) , or a block error rate (BLER) from the first base station; and

reselecting to a second base station different than the first base station upon locally releasing the RRC connection with the first base station.
The method of claim 1, further comprising:

initiating the local release of the RRC connection upon determining that at least one of a second reference signal received power (RSRP) or a second reference signal received quality (RSRQ) of the second base station is greater than a first RSRP or a first RSRQ of the first base station.
The method of claim 2, wherein the RRC connection with the first base station is locally released upon determining that at least one of the SNR from the first base station is less than an SNR threshold, the SINR from the first base station is less than a SINR threshold, or the BLER from the first base station is greater than a BLER threshold for a time period greater than a time threshold.
The method of claim 2, further comprising:

sending a measurement report to the first base station indicating that at least one of the RSRP of the second base station is greater than the RSRP of the first base station, or the RSRQ of the second base station is greater than the RSRQ of the first base station,

wherein the RRC connection to the first base station is locally released before the first base station hands off the UE to the second base station.
An apparatus for wireless communication of a user equipment (UE) , comprising:

means for locally releasing a radio resource control (RRC) connection with a first base station based on at least one of a signal to noise ratio (SNR) , a signal to interference plus noise ratio (SINR) , or a block error rate (BLER) from the first base station; and

means for reselecting to a second base station different than the first base station upon locally releasing the RRC connection with the first base station.
The apparatus of claim 5, further comprising:

means for initiating the local release of the RRC connection upon determining that at least one of a second reference signal received power (RSRP) or a second reference signal received quality (RSRQ) of the second base station is greater than a first RSRP or a first RSRQ of the first base station.
The apparatus of claim 6, wherein the RRC connection with the first base station is locally released upon determining that at least one of the SNR from the first base station is less than an SNR threshold, the SINR from the first base station is less than a SINR threshold, or the BLER from the first base station is greater than a BLER threshold for a time period greater than a time threshold.
The apparatus of claim 6, further comprising:

means for sending a measurement report to the first base station indicating that at least one of the RSRP of the second base station is greater than the RSRP of the first base station, or the RSRQ of the second base station is greater than the RSRQ of the first base station,

wherein the RRC connection to the first base station is locally released before the first base station hands off the UE to the second base station.
An apparatus for wireless communication, comprising:

a memory; and

at least one processor coupled to the memory and configured to:

locally release a radio resource control (RRC) connection with a first base station based on at least one of a signal to noise ratio (SNR) , a signal to interference plus noise ratio (SINR) , or a block error rate (BLER) from the first base station; and

reselect to a second base station different than the first base station upon locally releasing the RRC connection with the first base station.
The apparatus of claim 9, the at least one processor is further configured to:

initiate the local release of the RRC connection upon determining that at least one of a second reference signal received power (RSRP) or a second reference signal received quality (RSRQ) of the second base station is greater than a first RSRP or a first RSRQ of the first base station.
The apparatus of claim 10, wherein the RRC connection with the first base station is locally released upon determining that at least one of the SNR from the first base station is less than an SNR threshold, the SINR from the first base station is less than a SINR threshold, or the BLER from the first base station is greater than a BLER threshold for a time period greater than a time threshold.
The apparatus of claim 10, the at least one processor is further configured to:

send a measurement report to the first base station indicating that at least one of the RSRP of the second base station is greater than the RSRP of the first base station, or the RSRQ of the second base station is greater than the RSRQ of the first base station,

wherein the RRC connection to the first base station is locally released before the first base station hands off the UE to the second base station.
A computer-readable medium storing computer executable code, the code when executed by a processor cause the processor to:

locally release a radio resource control (RRC) connection with a first base station based on at least one of a signal to noise ratio (SNR) , a signal to interference plus noise ratio (SINR) , or a block error rate (BLER) from the first base station; and

reselect to a second base station different than the first base station upon locally releasing the RRC connection with the first base station.