WO2021184242A1

WO2021184242A1 - Handover conditions for a handover measurement report in a wide area network (wan)

Info

Publication number: WO2021184242A1
Application number: PCT/CN2020/079927
Authority: WO
Inventors: Jinglin Zhang; Haojun WANG; Yi Liu; Zhenqing CUI; Hong Wei
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2020-03-18
Filing date: 2020-03-18
Publication date: 2021-09-23
Anticipated expiration: 2022-09-18

Abstract

This disclosure provides systems, methods, and apparatus, including computer programs encoded on computer-readable media, for implementing handover conditions for a handover measurement report. A UE may determine a first set of signal quality measurements from one or more reference signals obtained from a first base station (BS), and determine a second set of signal quality measurements from one or more reference signals obtained from a second BS. The UE may determine that a first handover condition is met, and determine whether a second handover condition is met based on a first signal quality measurement of the first set of signal quality measurements and a second signal quality measurement of the second set of signal quality measurements in response to determining the first handover condition is met. The UE may output a handover measurement report to the first BS in response to determining the second handover condition is met.

Description

HANDOVER CONDITIONS FOR A HANDOVER MEASUREMENT REPORT IN A WIDE AREA NETWORK (WAN)

TECHNICAL FIELD

Aspects of the present disclosure relate generally to wireless communication and to techniques for implementing handover conditions for a handover measurement report in a wide area network (WAN) .

DESCRIPTION OF THE RELATED TECHNOLOGY

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (such as time, frequency, and power) . A wireless multiple-access communications system may include a number of base stations (BSs) , each simultaneously supporting communications for multiple communication devices, which may be otherwise known as user equipment (UE) .

To meet the growing demands for expanded mobile broadband connectivity, wireless communication technologies are advancing from the long term evolution (LTE) technology to a next generation new radio (NR) technology, which may be referred to as 5 _th Generation (5G) or 5G NR. For example, NR is designed to provide a lower latency, a higher bandwidth or a higher throughput, and a higher reliability than LTE. NR is designed to operate over a wide array of spectrum bands, for example, from low-frequency bands below about 1 gigahertz (GHz) and mid-frequency bands from about 1 GHz to about 6 GHz, to high-frequency bands such as millimeter wave (mmWave) bands. NR is also designed to operate across different spectrum types, from licensed spectrum to unlicensed and shared spectrum. Spectrum sharing enables operators to opportunistically aggregate spectrums to dynamically support high-bandwidth services. Spectrum sharing can extend the benefit of NR technologies to operating entities that may not have access to a licensed spectrum.

SUMMARY

The systems, methods, and devices of this disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

One innovative aspect of the subject matter described in this disclosure can be implemented in a method for wireless communication performed by an apparatus of a first user equipment (UE) . The method may include determining a first set of signal quality measurements from one or more reference signals obtained from a first base station (BS) of a wireless communication network. The first BS may have a wireless connection with the UE. The method may include determining a second set of signal quality measurements from one or more reference signals obtained from a second BS of the wireless communication network, and determining that a first handover condition is met based on a comparison of the first set of signal quality measurements and the second set of signal quality measurements. The method may include determining whether a second handover condition is met based on a first signal quality measurement of the first set of signal quality measurements and a second signal quality measurement of the second set of signal quality measurements in response to determining the first handover condition is met, and outputting a handover measurement report for transmission to the first BS in response to determining the second handover condition is met.

In some implementations, the wireless communication network includes a 5G New Radio (NR) network.

In some implementations, the method may include determining the first signal quality measurement of the first set of signal quality measurements associated with the first BS and the second signal quality measurement of the second set of signal quality measurements associated with the second BS, determining whether the first signal quality measurement associated with the first BS is less than the second signal quality measurement associated with the second BS, and determining that the second handover condition is met in response to determining the first signal quality measurement is less than the second signal quality measurement.

In some implementations, the first signal quality measurement of the first set of signal quality measurements may be a first maximum signal quality measurement of the first set of signal quality measurements, and the second signal quality measurement of the second set of signal quality measurements may be a second maximum signal quality measurement of the second set of signal quality measurements.

In some implementations, the method may include determining the first maximum signal quality measurement of the first set of signal quality measurements associated with the first BS and the second maximum signal quality measurement of the second set of signal quality measurements associated with the second BS, determining whether the first maximum signal quality measurement associated with the first BS is less than the second maximum signal quality measurement associated with the second BS, and determining that the second handover condition is met in response to determining the first maximum signal quality measurement is less than the second maximum signal quality measurement.

In some implementations, the method may include determining that the second handover condition is not met in response to determining the first maximum signal quality measurement is greater than or equal to the second maximum signal quality measurement, and determining not to transmit the handover measurement report to the first BS in response to determining the second handover condition is not met.

In some implementations, the method may include determining whether a handover event has been triggered based on the first set of signal quality measurements and the second set of signal quality measurements. The method may include determining that the first handover condition is met in response to determining the handover event has been triggered based on the first set of signal quality measurements and the second set of signal quality measurements.

In some implementations, the method may include determining a first average of the first set of signal quality measurements associated with the first BS and a second average of the second set of signal quality measurements associated with the second BS, determining whether a handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements, and determining that the first handover condition is met in response to determining the handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements.

In some implementations, the handover event may be an A3 event, and the first handover condition may be an A3 event condition or a handover event measurement report trigger condition.

In some implementations, the method may include determining the first handover condition is not met in response to determining the handover event has not been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements.

In some implementations, the first set of signal quality measurements that are determined from one or more reference signals obtained from the first BS may be reference signal received power (RSRP) measurements, reference signal received quality (RSRQ) measurements, or signal-to-interference-plus-noise ratio (SINR) measurements determined from one or more synchronized signal block (SSB) signals obtained from the first BS. The second set of signal quality measurements that are determined from one or more reference signals obtained from the second BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more SSB signals obtained from the second BS.

In some implementations, the first set of signal quality measurements that are determined from one or more reference signals obtained from the first BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more channel state information reference signals (CSI-RSs) obtained from the first BS. The second set of signal quality measurements that are determined from one or more reference signals obtained from the second BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more CSI-RSs obtained from the second BS.

In some implementations, the method may include determining whether to perform the first set of signal quality measurements and the second set of signal quality measurements using RSRP measurements, RSRQ measurements, or SINR measurements based on a measurement report configuration information element (IE) obtained from the first BS.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a method for wireless communication performed by an apparatus of a first BS. The method may include outputting one or more reference signals for transmission to a UE of a wireless communication network. The UE may have a wireless connection with the first BS. The method may include obtaining a handover measurement report from the UE after the transmission of the one or more reference signals from the first BS to the UE, and determining that a first handover condition is met based on the handover measurement report. The first handover condition may be indicative that a handover event was triggered at the UE based on a comparison of a first set of signal quality measurements associated with the first BS and a second set of signal quality measurements associated with a second BS of the wireless communication network. The method may include determining that a second handover condition is met based on the handover measurement report. The second handover condition may be indicative that a first signal quality measurement of the first set of signal quality measurements is less than a second signal quality measurement of the second set of signal quality measurements. The method may include performing a handover of the UE from the first BS to the second BS in response to obtaining the handover measurement report.

In some implementations, the first signal quality measurement of the first set of signal quality measurements may be a first maximum signal quality measurement of the first set of signal quality measurements, and the second signal quality measurement of the second set of signal quality measurements may be a second maximum signal quality measurement of the second set of signal quality measurements. The second handover condition may be indicative that the first maximum signal quality measurement is less than the second maximum signal quality measurement.

In some implementations, the handover event may be triggered at the UE based on a comparison of a first average of the first set of signal quality measurements and a second average of the second set of signal quality measurements.

In some implementations, the method may include outputting one or more SSB signals for transmission to the UE. The first set of signal quality measurements may be RSRP measurements, RSRQ measurements, or SINR measurements determined by the UE from the one or more SSB signals obtained from the first BS, and the second set of signal quality measurements may be RSRP measurements, RSRQ measurements, or SINR measurements determined by the UE from one or more SSB signals obtained from the second BS.

In some implementations, the method may include outputting one or more CSI-RSs for transmission to the UE. The first set of signal quality measurements may be RSRP measurements, RSRQ measurements, or SINR measurements determined by the UE from the one or more CSI-RSs obtained from the first BS, and the second set of signal quality measurements may be RSRP measurements, RSRQ measurements, or SINR measurements determined by the UE from one or more CSI-RSs obtained from the second BS.

Another innovative aspect of the subject matter described in this disclosure can be implemented by an apparatus of a UE for wireless communication including one or more processors and an interface. The one or more processors may be configured to determine a first set of signal quality measurements from one or more reference signals obtained from a first BS of a wireless communication network. The first BS may have a wireless connection with the UE. The one or more processors may be configured to determine a second set of signal quality measurements from one or more reference signals obtained from a second BS of the wireless communication network, determine that a first handover condition is met based on a comparison of the first set of signal quality measurements and the second set of signal quality measurements, and determine whether a second handover condition is met based on a first signal quality measurement of the first set of signal quality measurements and a second signal quality measurement of the second set of signal quality measurements in response to a determination that the first handover condition is met. The interface may be configured to output a handover measurement report for transmission to the first BS in response to a determination that the second handover condition is met.

In some implementations, the one or more processors may be further configured to determine the first signal quality measurement of the first set of signal quality measurements associated with the first BS and the second signal quality measurement of the second set of signal quality measurements associated with the second BS, determine whether the first signal quality measurement associated with the first BS is less than the second signal quality measurement associated with the second BS, and determine that the second handover condition is met in response to determining the first signal quality measurement is less than the second signal quality measurement.

In some implementations, the one or more processors may be further configured to determine the first maximum signal quality measurement of the first set of signal quality measurements associated with the first BS and the second first maximum signal quality measurement of the second set of signal quality measurements associated with the second BS, determine whether the first maximum signal quality measurement associated with the first BS is less than the second maximum signal quality measurement associated with the second BS, and determine that the second handover condition is met in response to a determination that the first maximum signal quality measurement is less than the second maximum signal quality measurement.

In some implementations, the one or more processors may be further configured to determine a first average of the first set of signal quality measurements associated with the first BS and a second average of the second set of signal quality measurements associated with the second BS, determine whether a handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements, and determine that the first handover condition is met in response to a determination that the handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements.

In some implementations, the one or more processors may be further configured to determine whether to perform the first set of signal quality measurements and the second set of signal quality measurements using RSRP measurements, RSRQ measurements, or SINR measurements based on a measurement report configuration IE obtained from the first BS.

Another innovative aspect of the subject matter described in this disclosure can be implemented by an apparatus for wireless communication. The apparatus may include means for determining a first set of signal quality measurements from one or more reference signals obtained from a first BS of a wireless communication network. The first BS may have a wireless connection with the apparatus. The apparatus may include means for determining a second set of signal quality measurements from one or more reference signals obtained from a second BS of the wireless communication network, means for determining that a first handover condition is met based on a comparison of the first set of signal quality measurements and the second set of signal quality measurements, means for determining whether a second handover condition is met based on a first signal quality measurement of the first set of signal quality measurements and a second signal quality measurement of the second set of signal quality measurements in response to a determination that the first handover condition is met, and means for outputting a handover measurement report for transmission to the first BS in response to a determination that the second handover condition is met.

The apparatus may further include means for determining the first signal quality measurement of the first set of signal quality measurements associated with the first BS and the second signal quality measurement of the second set of signal quality measurements associated with the second BS, means for determining whether the first signal quality measurement associated with the first BS is less than the second signal quality measurement associated with the second BS, and means for determining that the second handover condition is met in response to determining the first signal quality measurement is less than the second signal quality measurement.

The apparatus may include means for determining the first maximum signal quality measurement of the first set of signal quality measurements associated with the first BS and the second first maximum signal quality measurement of the second set of signal quality measurements associated with the second BS, means for determining whether the first maximum signal quality measurement associated with the first BS is less than the second maximum signal quality measurement associated with the second BS, and means for determining that the second handover condition is met in response to a determination that the first maximum signal quality measurement is less than the second maximum signal quality measurement.

The apparatus may further include means for determining a first average of the first set of signal quality measurements associated with the first BS and a second average of the second set of signal quality measurements associated with the second BS, means for determining whether a handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements, and means for determining that the first handover condition is met in response to a determination that the handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements.

Another innovative aspect of the subject matter described in this disclosure can be implemented by an apparatus of a first BS for wireless communication including an interface and one or more processors. The interface may be configured to output one or more reference signals for transmission to a UE of a wireless communication network. The UE may have a wireless connection with the first BS. The interface may be configured to obtain a handover measurement report from the UE after the transmission of the one or more reference signals from the first BS to the UE. The one or more processors may be configured to determine that a first handover condition is met based on the handover measurement report. The first handover condition may be indicative that a handover event was triggered at the UE based on a comparison of a first set of signal quality measurements associated with the first BS and a second set of signal quality measurements associated with a second BS of the wireless communication network. The one or more processors may be configured to determine that a second handover condition is met based on the handover measurement report. The second handover condition may be indicative that a first signal quality measurement of the first set of signal quality measurements is less than a second signal quality measurement of the second set of signal quality measurements. The one or more processors may be configured to perform a handover of the UE from the first BS to the second BS in response to a reception of the handover measurement report.

Another innovative aspect of the subject matter described in this disclosure can be implemented by a non-transitory computer-readable medium having stored therein instructions which, when executed by a processor of a UE, cause the UE to determine a first set of signal quality measurements from one or more reference signals obtained from a first BS of a wireless communication network. The first BS may have a wireless connection with the UE. The instructions, when executed by the processor of the UE, may further cause the UE to determine a second set of signal quality measurements from one or more reference signals obtained from a second BS of the wireless communication network, determine that a first handover condition is met based on a comparison of the first set of signal quality measurements and the second set of signal quality measurements, determine whether a second handover condition is met based on a first signal quality measurement of the first set of signal quality measurements and a second signal quality measurement of the second set of signal quality measurements in response to a determination that the first handover condition is met, and output a handover measurement report for transmission to the first BS in response to a determination that the second handover condition is met.

In some implementations, the instructions, when executed by the processor of the UE, may further cause the UE to determine the first signal quality measurement of the first set of signal quality measurements associated with the first BS and the second signal quality measurement of the second set of signal quality measurements associated with the second BS, determine whether the first signal quality measurement associated with the first BS is less than the second signal quality measurement associated with the second BS, and determine that the second handover condition is met in response to a determination that the first signal quality measurement is less than the second signal quality measurement.

In some implementations, the instructions, when executed by the processor of the UE, may further cause the UE to determine the first maximum signal quality measurement of the first set of signal quality measurements associated with the first BS and the second maximum signal quality measurement of the second set of signal quality measurements associated with the second BS, determine whether the first maximum signal quality measurement associated with the first BS is less than the second maximum signal quality measurement associated with the second BS, and determine that the second handover condition is met in response to a determination that the first maximum signal quality measurement is less than the second maximum signal quality measurement.

In some implementations, the instructions, when executed by the processor of the UE, may further cause the UE to determine a first average of the first set of signal quality measurements associated with the first BS and a second average of the second set of signal quality measurements associated with the second BS, determine whether a handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements, and determine that the first handover condition is met in response to a determination that the handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements.

Aspects of the subject matter described in this disclosure can be implemented in a device, a software program, a system, or other means to perform any of the above-mentioned methods.

Details of one or more implementations of the subject matter described in this disclosure are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings and the claims. Note that the relative dimensions of the following figures may not be drawn to scale.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a system diagram of an example wireless communication network.

Figure 2 is a block diagram conceptually illustrating an example of a base station (BS) in communication with a user equipment (UE) .

Figure 3A shows an example 5G NR frame structure having multiple slots including a first slot.

Figure 3B shows an example of downlink (DL) channels within each subframe of the 5G NR frame structure.

Figure 4 shows a system diagram of an example wireless communication network including a UE, a first BS of a 5G NR network, and a second BS of the 5G NR network configured to implement handover conditions for a handover measurement report.

Figure 5 shows an example message flow that shows a UE, a first BS of a 5G NR network, and a second BS of a 5G NR network configured to implement handover conditions for a handover measurement report.

Figure 6 depicts a flowchart with example operations performed by an apparatus of a UE for implementing handover conditions for handover measurement reports in a wireless communication network.

Figure 7 depicts a flowchart with example operations performed by an apparatus of a first BS for performing a handover operation in a wireless communication network in response to receiving a handover measurement reports triggered based on handover conditions

Figure 8 shows a conceptual diagram of an example configuration message and example configuration information element related to the handover conditions analysis and the handover measurement reports.

Figure 9 shows a block diagram of an example wireless communication device.

Like reference numbers and designations in the various drawings indicate like elements.

DETAILED DESCRIPTION

The following description is directed to certain implementations for the purposes of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. The examples in this disclosure are based on wireless network communications in wide area networks (WANs) . However, the described implementations may be implemented in any device, system or network that is capable of transmitting and receiving radio frequency signals according to any of the wireless communication standards, including any of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, the

standard, code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal FDMA (OFDMA) , single-carrier FDMA (SC-FDMA) , Global System for Mobile communications (GSM) , GSM/General Packet Radio Service (GPRS) , Enhanced Data GSM Environment (EDGE) , Terrestrial Trunked Radio (TETRA) , Wideband-CDMA (W-CDMA) , Evolution Data Optimized (EV-DO) , 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Speed Packet Access (HSPA) , High Speed Downlink Packet Access (HSDPA) , High Speed Uplink Packet Access (HSUPA) , Evolved High Speed Packet Access (HSPA+) , Long Term Evolution (LTE) , 5 ^th Generation (5G) or new radio (NR) , Advanced Mobile Phone Service (AMPS) , or other known signals that are used to communicate within a wireless, cellular or internet of things (IoT) network, such as a system utilizing 3G, 4G or 5G, or further implementations thereof, technology.

An OFDMA network may implement a radio technology such as evolved UTRA (EUTRA) , IEEE 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and GSM are part of universal mobile telecommunication system (UMTS) . In particular, 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 LTE is a 3GPP project which was aimed at improving the UMTS mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure relates to 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.

In particular, 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. In order 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 a Ultra-high density (such as ～1M nodes/km ₂) , ultra-low complexity (such as ～10s of bits/sec) , ultra-low energy (such as ～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 (such as ～99.9999%reliability) , ultra-low latency (such as ～ 1 ms) , and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (such as ～ 10 Tbps/km ₂) , extreme data rates (such as multi-Gbps rate, 100+ Mbps user experienced rates) , and deep awareness with advanced discovery and optimizations.

The 5G NR may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI) ; having 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 with 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 5, 10, 20 MHz, and the like bandwidth (BW) . 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 BW. 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 BW. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500 MHz BW.

The scalable numerology of the 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.

A wireless communication network (which also may be referred to as a WAN) may include a 5G NR radio access technology (RAT) of a 5G NR network. A user equipment (UE) of the wireless communication network may use the 5G NR RAT for wireless communications with the 5G NR network. When the UE has established a connection with a first base station (BS) of the 5G NR network, the UE may periodically receive one or more reference signals from the first BS and also one or more reference signals from one or more neighboring BSs, such as a second BS. The UE may perform signal quality measurements on the reference signals received from the first and second BSs to determine the quality of the signals and determine whether to transmit a handover measurement report to the first BS based on an analysis of the signal quality measurements. The first BS may perform a handover of the UE from the first BS to the second BS based on the handover measurement report. In some implementations, the signal quality measurements may be reference signal received power (RSRP) measurements, reference signal received quality (RSRQ) measurements, or signal-to-interference-plus-noise ratio (SINR) measurements.

In order to determine whether to initiate a handover operation, the UE may analyze the signal quality measurements from the first and second BSs to determine whether a handover event is triggered. The first BS may configure the handover event, which also may be referred to as an A3 event. In some implementations, the first BS may configure the A3 event to instruct the UE to send a handover measurement report to the first BS when certain conditions (which may be referred to as handover event conditions or A3 event conditions) are satisfied. The A3 event is one of various measurement reporting events described in Section 5.5.4.4 of the 3GPP technical specification (TS) 38.133, version 15.8.0 (2019-12) (hereafter “TS 38.133” ) . In some implementations, the UE may compare a first average of a first set of signal quality measurements associated with the first BS to a second average of a second set of signal quality measurements associated with the second BS. The UE may determine whether a handover event condition (such as an A3 event condition) associated with the handover event (such as the A3 event) is satisfied based on the comparison of the first average associated with the first BS to the second average associated with the second BS. The A3 event may be triggered when the A3 event condition is satisfied. The UE may transmit a handover measurement report to the first BS to perform the handover operation when the A3 event is triggered. However, in some instances, even when the A3 event condition is met, the first BS may be providing relatively equal or superior quality service to the UE compared to the second BS, and thus a handover operation may not be recommended. For example, even when the A3 event condition is satisfied based on the comparison of the first and second averages of the signal quality measurements, one or more of the signal quality measurements from the first BS may have a higher quality than any of the signal quality measurements from the second BS. Thus, if one or more of the signal quality measurements from the first BS have a higher quality than any of the signal quality measurements from the second BS, a handover from the first BS to the second BS may not be recommended.

In some implementations, after determining that a first handover condition is satisfied (such as the A3 event condition) , the UE 120 may determine whether another condition is satisfied before transmitting a handover measurement report. In some implementations, the UE 120 may determine whether a second handover condition is satisfied. For example, after determining that the first handover condition is satisfied, the UE 120 may determine whether a first signal quality measurement associated with the first BS is less than a second signal quality measurement associated with the second BS. The UE 120 may determine that the second handover condition is satisfied in response to determining the first signal quality measurement associated with the first BS is less than the second signal quality measurement associated with the second BS. For example, when the signal quality measurements are RSRPs, the first signal quality measurement may be a first RSRP having a first power value and the second signal quality measurement may be a second RSRP having a second power value. The UE 120 may determine that the second handover condition is satisfied in response to determining the first RSRP is less than the second RSRP. In some implementations, the UE 120 may determine that the second handover condition is satisfied in response to determining a first maximum signal quality measurement associated with the first BS is less than a second maximum signal quality measurement associated with the second BS. For example, when the signal quality measurements are RSRPs, the first maximum signal quality measurement may be a first maximum RSRP having a first power value and the second maximum signal quality measurement may be a second maximum RSRP having a second power value. The UE 120 may determine that the second handover condition is satisfied in response to determining the first maximum RSRP is less than the second maximum RSRP.

Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. The UE performing additional analysis on the signal quality measurements derived from the first and second BSs to determine whether the first and second handover conditions are satisfied avoid unnecessary handovers. Also, since the UE does not transmit the handover measurement report unless both the first and second handover conditions are satisfied, the number of signal exchanges and thus the network traffic may be reduced.

Figure 1 is a system diagram of an example wireless communication network 100. The wireless communication network 100 may be an LTE network or a 5G NR network, or a combination thereof. The wireless communication network 100 includes a number of base stations (BSs) 105 (individually labeled as 105A, 105B, 105C, 105D, 105E, and 105F) and other network entities. A BS 105 may be a station that communicates with UEs 115 and also may be referred to as an evolved node B (eNB) , a next generation eNB (gNB) , an access point, and the like. In some implementations, a BS 105 may represent an eNB of an LTE network or a gNB of a 5G NR network, or a combination thereof. Each BS 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 BS 105 or a BS subsystem serving the coverage area, depending on the context in which the term is used.

A BS 105 may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, or other types of cells. A macro cell generally covers a relatively large geographic area (such as several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A pico cell generally covers a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell generally covers a relatively small geographic area (such as a home) and, in addition to unrestricted access, also may provide restricted access by UEs having an association with the femto cell (such as UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) . A BS for a macro cell may be referred to as a macro BS. A BS for a small cell may be referred to as a small cell BS, a pico BS, a femto BS or a home BS. In the example shown in Figure 1, the BSs 105D and 105E may be regular macro BSs, while the BSs 105A-105C may be macro BSs enabled with three dimensions (3D) , full dimensions (FD) , or massive MIMO. The BSs 105A-105C may take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. The BS 105F may be a small cell BS which may be a home node or portable access point. A BS 105 may support one or multiple (such as two, three, four, and the like) cells.

The wireless communication network 100 may support synchronous or asynchronous operation. For synchronous operation, the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.

The UEs 115 are dispersed throughout the wireless communication network 100, and each UE 115 may be stationary or mobile. A UE 115 also may be referred to as a terminal, a mobile station, a wireless device, a subscriber unit, a station, or the like. A UE 115 may be a mobile phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a wearable device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a smart appliance, a drone, a video camera, a sensor, or the like. In one aspect, a UE 115 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, the UEs 115 that do not include UICCs also may be referred to as IoT devices or internet of everything (IoE) devices. The UEs 115A-115D are examples of mobile smart phone-type devices that may access the wireless communication network 100. A UE 115 also may be a machine specifically configured for connected communication, including machine type communication (MTC) , enhanced MTC (eMTC) , narrowband IoT (NB-IoT) , and the like. The UEs 115E-115L are examples of various machines configured for communication that access the wireless communication network 100. A UE 115 may be able to communicate with any type of the BSs, whether macro BS, small cell, or the like. In Figure 1, a lightning bolt is representative of a communication link that indicates wireless transmissions between a UE 115 and a serving BS 105, which is a BS designated to serve the UE 115 on the downlink and uplink, or desired transmission between BSs, and backhaul transmissions between BSs.

In operation, the BSs 105A-105C may serve the

UEs

115A and 115B using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. The macro BS 105D may perform backhaul communications with the BSs 105A-105C, as well as the BS 105F (which may be a small cell BS) . The macro BS 105D also may transmit multicast services which are subscribed to and received by the

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.

The BSs 105 also may communicate with a core network. The core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs 105 (such as a gNB or an access node controller (ANC) ) may interface with the core network through backhaul links (such as NG-C and NG-U) and may perform radio configuration and scheduling for communication with the UEs 115. In various examples, the BSs 105 may communicate, either directly or indirectly (such as through core network) , with each other over backhaul links, which may be wired or wireless communication links.

The wireless communication network 100 also may support mission critical communications with ultra-reliable and redundant links for mission critical devices, such as the UE 115E, which may be a drone. Redundant communication links with the UE 115E may include links from the macro BSs 105D and 105E, as well as links from the small cell BS 105F. Other machine type devices, such as the UE 115F and UE 115G (such as video cameras or smart lighting) , the UE 115H (such as a smart meter) , and UE 115I (such as a wearable device) may communicate through the wireless communication network 100 either directly with the BSs, such as the small cell BS 105F, and the macro BS 105E, or in multi-hop configurations by communicating with another user device which relays its information to the wireless communication network 100. For example, the UE 115H may communicate smart meter information to the UE 115I (such as a wearable device or mobile phone) , which may then report to the wireless communication network 100 through the small cell BS 105F. The wireless communication network 100 also may provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as in vehicle-to-vehicle (V2V) communications, as shown by UEs 115J-115L.

In some implementations, the wireless communication network 100 may utilize OFDM-based waveforms for communications. An OFDM-based system may partition the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, bins, or the like. Each subcarrier may be modulated with data. In some instances, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system BW. The system BW also may be partitioned into subbands. In other instances, the subcarrier spacing and/or the duration of TTIs may be scalable.

The BSs 105 may assign or schedule transmission resources (such as in the form of time-frequency resource blocks (RB) ) for downlink (DL) and uplink (UL) transmissions in the wireless communication network 100. DL refers to the transmission direction from a BS 105 to a UE 115, whereas UL refers to the transmission direction from a UE 115 to a BS 105. The communication can be in the form of radio frames. A radio frame may be divided into a plurality of subframes or slots. Each slot may be further divided into mini-slots. In a FDD mode, simultaneous UL and DL transmissions may occur in different frequency bands. For example, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In a TDD mode, UL and DL transmissions occur at different time periods using the same frequency band. For example, a subset of the subframes (such as the DL subframes) in a radio frame may be used for DL transmissions, and another subset of the subframes (such as the UL subframes) in the radio frame may be used for UL transmissions.

The DL subframes and the UL subframes can be further divided into several regions. For example, each DL or UL subframe may have pre-defined regions for transmissions of reference signals, control information, and data. Reference signals are predetermined signals that facilitate the communications between the BSs 105 and the UEs 115. For example, a reference signal can have a particular pilot pattern or structure, where pilot tones may span across an operational BW or frequency band, each positioned at a pre-defined time and a pre-defined frequency. For example, a BS 105 may transmit cell-specific reference signals (CRSs) or channel state information reference signals (CSI-RSs) to enable a UE 115 to estimate a DL channel. Similarly, a UE 115 may transmit sounding reference signals (SRSs) to enable a BS 105 to estimate a UL channel. Control information may include resource assignments and protocol controls. Data may include protocol data and operational data. In some aspects, the BSs 105 and the UEs 115 may communicate using self-contained subframes. A self-contained subframe may include a portion for DL communication and a portion for UL communication. A self-contained subframe can be DL-centric or UL-centric. A DL-centric subframe may include a longer duration for DL communication than for UL communication. A UL-centric subframe may include a longer duration for UL communication than for UL communication.

In some aspects, the wireless communication network 100 may be an NR network deployed over a licensed spectrum or an NR network deployed over an unlicensed spectrum (such as NR-U and NR-U lite networks) . The BSs 105 can transmit synchronization signals, including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) , in the wireless communication network 100 to facilitate synchronization. The BSs 105 can broadcast system information associated with the wireless communication network 100 (such as a master information block (MIB) , remaining system information (RMSI) , and other system information (OSI) ) to facilitate initial network access. In some instances, the BSs 105 may broadcast one or more of the PSS, the SSS, and the MIB in the form of synchronization signal block (SSBs) over a physical broadcast channel (PBCH) and may broadcast one or more of the RMSI and the OSI over a physical downlink shared channel (PDSCH) .

In some aspects, a UE 115 attempting to access the wireless communication network 100 may perform an initial cell search by detecting a PSS included in an SSB from a BS 105. The PSS may enable synchronization of period timing and may indicate a physical layer identity value. The UE 115 may then receive an SSS included in an SSB from the BS 105. The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The PSS and the SSS may be located in a central portion of a carrier or any suitable frequencies within the carrier.

After receiving the PSS and SSS, the UE 115 may receive an MIB. The MIB may include system information for initial network access and scheduling information for at least one of an RMSI and OSI. After decoding the MIB, the UE 115 may receive at least one of an RMSI and OSI. The RMSI and OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical uplink control channel (PUCCH) , physical uplink shared channel (PUSCH) , power control, and SRS.

After obtaining one or more of the MIB, the RMSI and the OSI, the UE 115 can perform a random access procedure to establish a connection with the BS 105. In some examples, the random access procedure may be a four-step random access procedure. For example, the UE 115 may transmit a physical random access channel (PRACH) , such as a PRACH preamble, and the BS 105 may respond with a random access response (RAR) . The RAR may include one or more of a detected random access preamble identifier (ID) corresponding to the PRACH preamble, timing advance (TA) information, a UL grant, a temporary cell-radio network temporary identifier (C-RNTI) , and a backoff indicator. Upon receiving the RAR, the UE 115 may transmit a connection request to the BS 105 and the BS 105 may respond with a connection response. The connection response may indicate a contention resolution. In some examples, the PRACH, the RAR, the connection request, and the connection response can be referred to as message 1 (MSG1) , message 2 (MSG2) , message 3 (MSG3) , and message 4 (MSG4) , respectively. In some examples, the random access procedure may be a two-step random access procedure, where the UE 115 may transmit a PRACH (including a PRACH preamble) and a connection request in a single transmission and the BS 105 may respond by transmitting a RAR and a connection response in a single transmission.

After establishing a connection, the UE 115 and the BS 105 can enter a normal operation stage, where operational data may be exchanged. For example, the BS 105 may schedule the UE 115 for UL and DL communications. The BS 105 may transmit UL and DL scheduling grants to the UE 115 via a PDCCH. The BS 105 may transmit a DL communication signal to the UE 115 via a PDSCH according to a DL scheduling grant. The UE 115 may transmit a UL communication signal to the BS 105 via a PUSCH or PUCCH according to a UL scheduling grant.

In some aspects, the wireless communication network 100 may operate over a system BW or a component carrier BW. The wireless communication network 100 may partition the system BW into multiple bandwidth parts (BWPs) . A BWP may be a certain portion of the system BW. For example, if the system BW is 100 MHz, the BWPs may each be 20 MHz or less. A BS 105 may dynamically assign a UE 115 to operate over a certain BWP. The assigned BWP may be referred to as the active BWP. The UE 115 may monitor the active BWP for signaling information from the BS 105. The BS 105 may schedule the UE 115 for UL or DL communications in the active BWP. In some implementations, the BS 105 may configure UEs 115 with narrowband operation capabilities (such as with transmission and reception limited to a BW of 20 MHz or less) to perform BWP hopping for channel monitoring and communications.

In some aspects, a BS 105 may assign a pair of BWPs within the component carrier to a UE 115 for UL and DL communications. For example, the BWP pair may include one BWP for UL communications and one BWP for DL communications. The BS 105 may additionally configure the UE 115 with one or more CORESETs in a BWP. A CORESET may include a set of frequency resources spanning a number of symbols in time. The BS 105 may configure the UE 115 with one or more search spaces for PDCCH monitoring based on the CORESETS. The UE 115 may perform blind decoding in the search spaces to search for DL control information (such as UL or DL scheduling grants) from the BS 105. For example, the BS 105 may configure the UE 115 with one or more of the BWPs, the CORESETS, and the PDCCH search spaces via RRC configurations.

In some aspects, the wireless communication network 100 may operate over a shared frequency band or an unlicensed frequency band, for example, at about 3.5 gigahertz (GHz) , sub-6 GHz or higher frequencies in the mmWave band. The wireless communication network 100 may partition a frequency band into multiple channels, for example, each occupying about 20 MHz. The BSs 105 and the UEs 115 may be operated by multiple network operating entities sharing resources in the shared communication medium and may employ a LBT procedure to acquire channel occupancy time (COT) in the share medium for communications. A COT may be non-continuous in time and may refer to an amount of time a wireless node can send frames when it has won contention for the wireless medium. Each COT may include a plurality of transmission slots. A COT also may be referred to as a transmission opportunity (TXOP) . The BS 105 or the UE 115 may perform an LBT in the frequency band prior to transmitting in the frequency band. The LBT can be based on energy detection or signal detection. For energy detection, the BS 105 or the UE 115 may determine that the channel is busy or occupied when a signal energy measured from the channel is greater than a certain signal energy threshold. For signal detection, the BS 105 or the UE 115 may determine that the channel is busy or occupied when a certain reservation signal (such as a preamble signal sequence) is detected in the channel.

Figure 2 is a block diagram conceptually illustrating an example 200 of a BS 110 in communication with a UE 120. In some aspects, BS 110 and UE 120 may respectively be one of the BSs and one of the UEs in wireless communication network 100 of Figure 1. BS 110 may be equipped with T antennas 234A through 234T, and UE 120 may be equipped with R antennas 252A through 252R, where in general T ≥ 1 and R ≥ 1.

At BS 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (for example, encode and modulate) the data for each UE based at least in part on the MCS (s) selected for the UE, and provide data symbols for all UEs. The transmit processor 220 also may process system information (for example, for semi-static resource partitioning information (SRPI) , etc. ) and control information (for example, CQI requests, grants, upper layer signaling, etc. ) and provide overhead symbols and control symbols. The transmit processor 220 also may generate reference symbols for reference signals (for example, the cell-specific reference signal (CRS) ) and synchronization signals (for example, the primary synchronization signal (PSS) and secondary synchronization signal (SSS) ) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (for example, precoding) on the data symbols, the control symbols, the overhead symbols, or the reference symbols, if applicable, and may provide T output symbol streams to T modulators-demodulators (MODs-DEMODs) 232A through 232T (which also may be referred to as mods/demods or modems) . Each MOD-DEMOD 232 may process a respective output symbol stream (for example, for OFDM, etc. ) to obtain an output sample stream. Each MOD-DEMOD 232 may further process (for example, convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from MODs-DEMODs 232A through 232T may be transmitted via T antennas 234A through 234T, respectively. According to various aspects described in more detail below, the synchronization signals can be generated with location encoding to convey additional information.

At UE 120, antennas 252A through 252R may receive the downlink signals from BS 110 or other BSs and may provide received signals to modulators-demodulators (MODs-DEMODs) 254A through 254R, respectively (which also may be referred to as mods/demods or modems) . Each MOD-DEMOD 254 may condition (for example, filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each MOD-DEMOD 254 may further process the input samples (for example, for OFDM, etc. ) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R MODs-DEMODs 254A through 254R, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (for example, demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller or processor (controller/processor) 280. A channel processor may determine reference signal received power (RSRP) , received signal strength indicator (RSSI) , reference signal received quality (RSRQ) , channel quality indicator (CQI) , etc. In some aspects, one or more components of UE 120 may be included in a housing.

On the uplink, at UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (for example, for reports including RSRP, RSSI, RSRQ, CQI, etc. ) from controller/processor 280. Transmit processor 264 also may generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by MODs-DEMODs 254A through 254R (for example, for DFT-s-OFDM, CP-OFDM, etc. ) , and transmitted to BS 110. At BS 110, the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by MOD-DEMOD 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to a controller or processor (i.e., controller/processor) 240. The BS 110 may include communication unit 244 and may communicate to network controller 130 via communication unit 244. The network controller 130 may include communication unit 294, a controller or processor (i.e., controller/processor) 290, and memory 292.

The controller/processor 240 of BS 110, the controller/processor 280 of UE 120, or any other component (s) of Figure 2 may perform one or more techniques associated with implementing handover conditions for handover measurement reports, as described in more detail elsewhere herein. For example, the controller/processor 240 of BS 110, the controller/processor 280 of UE 120, or any other component (s) (or combinations of components) of Figure 2 may perform or direct operations of, for example, the process depicted by flowchart 600 of Figure 6, the process depicted by flowchart 700 of Figure 7, or other processes as described herein, such as the processes described in Figures 4 and 5. The

memories

242 and 282 may store data and program codes for BS 110 and UE 120, respectively. A scheduler 246 may schedule UEs for data transmission on the downlink, the uplink, or a combination thereof.

The stored program codes, when executed by the controller/processor 280 or other processors and modules at UE 120, may cause the UE 120 to perform operations described with respect to the process depicted by flowchart 600 of Figure 6, or other processes as described herein, such as the processes described in Figures 4 and 5. The stored program codes, when executed by the controller/processor 240 or other processors and modules at BS 110, may cause the BS 110 to perform operations described with respect to the process depicted by flowchart 700 of Figure 7, or other processes as described herein, such as the processes described in Figures 4 and 5. A scheduler 246 may schedule UEs for data transmission on the downlink, the uplink, or a combination thereof.

In some aspects, UE 120 may include means for performing the process depicted by flowchart 600 of Figure 6, or other processes as described herein, such as the processes described in Figures 4 and 5. In some aspects, such means may include one or more components of UE 120 described in connection with Figure 2.

In some aspects, BS 110 may include means for performing the process depicted by flowchart 700 of Figure 7, or other processes as described herein, such as the processes described in Figures 4 and 5. In some aspects, such means may include one or more components of BS 110 described in connection with Figure 2.

While blocks in Figure 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, the TX MIMO processor 266, or another processor may be performed by or under the control of controller/processor 280.

Figure 3A shows an example 5G NR frame structure having multiple slots including a first slot 300. Figure 3B shows an example of DL channels 330 within each subframe of the 5G NR frame structure. In some cases, the 5G NR frame structure may be FDD in which, for a particular set of subcarriers (carrier system bandwidth) , slots within the set of subcarriers are dedicated for either DL or UL transmissions. In other cases, the 5G NR frame structure may be TDD in which, for a particular set of subcarriers (carrier system bandwidth) , slots within the set of subcarriers are dedicated for both DL and UL transmissions. In the examples shown in Figure 3A, the 5G NR frame structure is based on TDD, with slot 4 (such as first slot 300) configured with slot format 28 (with mostly DL) , where D indicates DL, U indicates UL, and X indicates that the slot is flexible for use between DL and UL, and with slot 3 configured with slot format 34 (with mostly UL) . While

slots

3 and 4 are shown with slot formats 34 and 28, respectively, any particular slot may be configured with any of the various available slot formats 0–61.

Slot formats

0 and 1 are all DL and all UL, respectively. Other slot formats 2–61 include a mix of DL, UL, and flexible symbols. UEs may be configured with the slot format, either dynamically through downlink control information (DCI) or semi-statically through radio resource control (RRC) signaling, by a slot format indicator (SFI) . The configured slot format also may apply to a 5G NR frame structure that is based on FDD.

Other wireless communication technologies may have a different frame structure and/or different channels. A frame (10 microseconds (ms) ) may be divided into 10 equally sized subframes (1 ms) . Each subframe may include one or more slots (which also may be referred as time slots) . Subframes also may 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 (such as 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) (such as for power limited scenarios) .

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 5 allow for 1, 2, 4, 8, 16, and 32 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 per slot and 2μ slots per 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 5. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz, and the numerology μ=5 has a subcarrier spacing of 480 kHz. The symbol length/duration is inversely related to the subcarrier spacing. Figures 3A-3B provide an example of slot configuration 0 with 14 symbols per slot and numerology μ=0 with 1 slot per subframe (such as first slot 300) . The subcarrier spacing is 15 kHz and symbol duration is approximately 66.7 microseconds (μs) .

A resource grid may be used to represent the 5G NR frame structure. As shown in first slot 300, each slot includes a resource block (RB) (also referred to as a physical RB (PRB) ) that extends across 12 consecutive subcarriers and across a number of symbols. The intersections of subcarriers and symbols of the RB define multiple resource elements (REs) . The number of bits carried by each RE depends on the modulation scheme.

As illustrated in Figure 3A, some of the REs of the first slot 300 carry a reference signal (RS) for the UE. In some instances, the RS may be (or may include) a pilot signal. In some configurations, one or more REs may carry a demodulation reference signal (DM-RS) (indicated as Rx for one particular configuration, where 100x is the port number, but other DM-RS configurations are possible) . In some configurations, one or more REs may carry a channel state information reference signal (CSI-RS) for channel measurement at the UE. The REs also may include a beam measurement reference signal (BRS) , a beam refinement reference signal (BRRS) , and a phase tracking reference signal (PT-RS) .

As illustrated in Figure 3B, the system bandwidth includes the DL channels 330 that are used for each 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 primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE to determine subframe or 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 block (SSB) or PBCH block (which also may be referred to as SS/PBCH Block) . 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.

Figure 4 shows a system diagram of an example wireless communication network including a UE, a first BS of a 5G NR network, and a second BS of the 5G NR network configured to implement handover conditions for a handover measurement report. The wireless communication network 400 shown in Figure 4 is based on the example wireless communication network 100 described in Figure 1. The wireless communication network 400 may include a UE 120, a BS 410, and a BS 411. The UE 120 may be an example implementation of the UE 115 shown in Figure 1 and the UE 120 shown in Figure 2. The BS 410 and the BS 411 may each be an example implementation of a BS 105 shown in Figure 1 and a BS 110 shown in Figure 2. Although not shown for simplicity, the wireless communication network 400 may include one or more additional BSs and one or more additional UEs. In some implementations, the BS 410 and the BS 411 may be a gNB that can implement a 5G NR radio access technology (RAT) described in this disclosure to manage communications of a 5G NR network, which may be part of the wireless communication network 400.

In some implementations, the UE 120 may include a signal measurement unit 422 and a handover conditions analysis unit 424. The signal measurement unit 422 may perform signal quality measurements on one or more reference signals received from the BS 410 and one or more reference signals received from the BS 411 to perform handover-related operations. The handover conditions analysis unit 424 may analyze the signal quality measurements based on at least a first handover condition and a second handover condition to determine whether to generate a measurement report. The BS 410 may include a reference signal unit 412 and a handover processing unit 414. Although not shown for simplicity, the BS 411 also may include a reference signal unit and a handover processing unit. The reference signal unit 412 may generate and transmit one or more reference signals to UEs of the wireless communication network 400, such as the UE 120. The handover processing unit 414 may receive and analyze measurement reports from the UEs, such as the UE 120, to determine whether to perform handover operation. In some implementations, the signal measurement unit 422 and the handover conditions analysis unit 424 may be implemented by the UE 120 using one or more of the components shown in Figure 2 for the UE 120, such as the controller/processor 280 and the memory 282. The reference signal unit 412 and the handover processing unit 414 may be implemented by the BS 410 (and the BS 411) using one or more of the components shown in Figure 2 for the BS 110, such as the controller/processor 240, the communication unit 244, and the memory 242.

The UE 120 may perform operations to establish a 5G NR connection with the wireless communication network 400. In some implementations, the UE 120 may establish a 5G NR connection 450 (which also may be referred to as a 5G NR communication link) with the BS 410 using a 5G NR RAT. The BS 410 that has established the 5G NR connection 450 with the UE 120 may be referred to as a serving BS or a serving cell. When the UE 120 is in motion or moves from a first position to a second position (as show by arrow 445) , the wireless communication network 400 may determine whether to perform a handover operation. For example, a user that is carrying the UE 120 may move from a first position that is closest to the BS 410 to a second position that is closest to the BS 411. The UE 120 and the BS 410 may perform handover-related operations to determine whether to perform a handover from the BS 410 to the BS 411. The BS 411 that has not established a 5G NR connection with the UE 120 (and is not serving the UE 120) may be referred to as a neighbor BS, neighboring BS, or a neighbor cell.

In some implementations, the UE 120 may receive one or more reference signals from the BS 410 via the 5G NR connection 450. For example, the UE 120 may receive one or more SSBs or one or more CSI-RSs via the 5G NR connection 450. Even though the UE 120 may not have an established connection with the BS 411, the UE 120 also may detect and receive one or more reference signals from the BS 411. For example, the UE 120 may receive one or more SSBs or one or more CSI-RSs from the BS 411. In some implementations, the UE 120 may receive the one or more reference signals from the BS 410 and may determine a first set of signal quality measurements based on the one or more reference signals. The first set of signal quality measurements derived from the one or more reference signals may indicate the quality of the connection between the UE 120 and the BS 410, which may be the serving BS. Also, the UE 120 may receive the one or more reference signals from the BS 411 and may determine a second set of signal quality measurements. The second set of signal quality measurements derived from the one or more reference signals received from the BS 411 may indicate the quality of the connection between the UE 120 and the BS 411, which may be a neighbor BS. In some implementations, the first and second sets of signal quality measurements may be reference signal received power (RSRP) measurements, reference signal received quality (RSRQ) measurements, or signal-to-interference-plus-noise ratio (SINR) measurements.

In some implementations, the BS 410 may indicate to the UE 120 whether to perform signal quality measurements based on SSBs or on CSI-RSs, and whether to use RSRP, RSRQ, or SINR for the signal quality measurements. For example, the BS 410 may provide an information element (IE) to the UE 120 that indicates whether to perform signal quality measurements based on SSBs or on CSI-RSs, and whether to use RSRP, RSRQ, or SINR for the signal quality measurements. For example, the BS 410 may provide a measurement report configuration IE, which may be referred to as a ReportConfigNR IE, that includes an NR-RS-Type parameter that indicates whether to perform signal quality measurements based on SSBs or on CSI-RSs, and a MeasTriggerQuantityOffset parameter that indicates whether to use RSRP, RSRQ, or SINR for the signal quality measurements.

In some implementations, after determining the first and second sets of signal quality measurements, the UE 120 may determine whether a first handover condition is met based on a comparison of the first and second sets of signal quality measurements. In some implementations, the UE 120 may determine a first average of the first set of signal quality measurements, and a second average of the second set of signal quality measurements. For example, the first and second averages may be linear averages. In some implementations, the UE 120 may determine whether the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements satisfy the first handover condition. The first handover condition may determine whether to trigger a handover event that triggers the transmission of a measurement report, as will be further described herein. The handover event may be referred to as an A3 event or a handover A3 event. The first handover condition also may be referred to as a handover event condition, an A3 event condition, or a handover event measurement report trigger condition. For example, the first handover condition may be a A3 event condition, which also may be referred to as a handover event measurement report trigger condition, and which is defined in Section 5.5.4.4 of the 3GPP technical specification (TS) 38.133, version 15.8.0 (2019-12) (hereafter “TS 38.133” ) .

The UE 120 may determine whether the first handover condition has been met, and thus whether to trigger the handover event, based on the comparison of the first set of signal quality measurements and the second set of signal quality measurements. For example, the UE 120 may determine whether the first handover condition has been met, and thus whether to trigger the handover event, based on a comparison of the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements. In some implementations, the UE 120 may determine whether the first handover condition has been met based on whether an A3 event has been triggered according to the A3 event condition defined in Section 5.5.4.4 of the TS 38.133. For example, the UE 120 may determine whether the A3 event condition has been satisfied by comparing the first average the first set of signal quality measurements and some defined offsets (configured by the wireless communication network 400) with the second average of the second set of signal quality measurements and other some offsets (configured by the wireless communication network 400) . For example, as defined in Section 5.5.4.4 of the TS 38.133, the UE 120 may determine a first sum of the first average the first set of signal quality measurements (Mp) , some defined measurement and cell specific offsets (Ofp and Ocp) and an A3 event offset (Off) , and a second sum of the second average of the second set of signal quality measurements (Mn) and some defined measurement and cell specific offsets (Ofn and Ocn) . If the second sum (with a hysteresis offset, Hys) is greater than the first sum, the UE 120 may determine the A3 event condition has been satisfied and thus the A3 event has been triggered. As shown in Section 5.5.4.4 of the TS 38.133, the A3 event condition for triggering the A3 event may be represented by Equation 1, which is reproduced below for reference.

Mn + Ofn + Ocn -Hys > Mp + Ofp + Ocp + Off Equation 1

In some implementations, after determining the first handover condition has been met, the UE 120 may determine whether a second handover condition is met based on the first and second sets of signal quality measurements. For example, after determining that the first handover condition is met, the UE 120 may determine whether a first signal quality measurement associated with the BS 410 is less than a second signal quality measurement associated with the BS 411. The UE 120 may determine that the second handover condition is satisfied in response to determining the first signal quality measurement associated with the BS 410 is less than the second signal quality measurement associated with the BS 411. In some implementations, the UE 120 may determine a first maximum signal quality measurement from the first set of signal quality measurements and a second maximum signal quality measurement from the second set of signal quality measurements. The UE 120 may determine whether the second handover condition is met based on a comparison of the first maximum signal quality measurement and the second maximum signal quality measurement. For example, the UE 120 may determine whether the first maximum signal quality measurement associated with the BS 410 is less than the second maximum signal quality measurement associated with the BS 411. The UE 120 may determine that the second handover condition is met in response to determining the first maximum signal quality measurement is less than the second maximum signal quality measurement. The UE 120 may transmit a measurement report (which also may be referred to as a handover measurement report or an A3 measurement report) to the BS 410 in response to determining the second handover condition is met. The measurement report may indicate to the BS 410 that the first and second handover conditions were satisfied. The measurement report also may trigger a handover operation at the BS 410 in order to perform handover of the UE 120 from the BS 410 to the BS 411. In some implementations, if the UE 120 determines that the first maximum signal quality measurement is greater than or equal to the second maximum signal quality measurement, the UE 120 may determine that the second handover condition has not been met. If the UE 120 determines that the second handover condition has not been met, the UE 120 may not transmit the measurement report to the BS 410. Also, the UE 120 may not transmit the measurement report to the BS 410 if the UE 120 determines that the first handover condition was not met.

As described herein, even when the first handover condition (such as an A3 event condition) is satisfied, it may be beneficial to the UE 120 not to perform a handover from the BS 410 to the BS 411, unless the second handover condition is met. For example, if the BS 410 indicates to the UE 120 to perform signal quality measurements based on SSBs and to use RSRP for the signal quality measurements, the first set of signal quality measurements associated with the BS 410 may include an RSRP1 and an RSRP2 and the second set of signal quality measurements associated with the BS 411 may include an RSRP3 and an RSRP4. The first average of the RSRP1 and the RSRP2 associated with the BS 410 may be represented by BS410_RSRP, and the second average of the RSRP3 and the RSRP4 associated with the BS 411 may be represented by BS411_RSRP. The UE 120 may compare the BS410_RSRP and the BS411_RSRP and may determine that these measurements satisfy the first handover condition (such as the A3 event condition) that triggers the A3 event. After determining that the first handover condition has been satisfied, the UE 120 may determine whether the second handover condition is satisfied by determining whether the maximum of the RSRP1 and RSRP2 associated with the BS 410 is less than the maximum of the RSRP 3 and RSRP 4 associated with the BS 411. If the maximum of the RSRP1 and RSRP2 is greater than or equal to the maximum of the RSRP3 and RSRP4, then the UE 120 may determine that the highest RSRP measurement was obtained from the BS 410. The UE 120 may determine that the second handover condition is not satisfied when the highest RSRP measurement was obtained from the BS 410, and thus the UE 120 may determine not to transmit the measurement report to the BS 410. Since the BS 410 does not receive the measurement report, the BS 410 may not perform the handover operation. If the maximum of the RSRP1 and RSRP2 associated with the BS 410 is less than the maximum of the RSRP 3 and RSRP 4 associated with the BS 411, then the highest RSRP measurement was obtained from the BS 411. The UE 120 may determine that the second handover condition is satisfied when the highest RSRP measurement was obtained from the BS 411, and thus the UE 120 may determine transmit the measurement report to the BS 410 in order to perform the handover from the BS 410 to the BS 411.

In some implementations, the BS 410 also may provide an indication to the UE 120 of the maximum number of signal quality measurements to average for the analysis of the first handover condition, and also a measurement threshold that limits the signal quality measurements that are averaged for the analysis of the first handover condition to the signal measurements that are above the measurement threshold. For example, the BS 410 may provide an IE to the UE 120 that indicates the maximum number of signal quality measurements and the measurement threshold. For example, the BS 410 may provide a measurement configuration IE, which also may be referred to as a MeasObjectNR IE, that includes a nrofSS-BlocksToAverage parameter and an absThreshSS-BlocksConsolidation parameter, according to Section 5.5.4.4 of the TS 38.133. The nrofSS-BlocksToAverage parameter indicates the maximum number of signal quality measurements to use for the averages, and the absThreshSS-BlocksConsolidation parameter indicates the measurement threshold when SSBs are used for the analysis of the first handover condition. The MeasObjectNR IE also may include a nrofCSI-RS-ResourcesToAverage parameter and an absThreshCSI-RS-Consolidation parameter, according to Section 5.5.4.4 of the TS 38.133. The nrofCSI-RS-ResourcesToAverage parameter indicates the maximum number of signal quality measurements to use for the averages, and the absThreshCSI-RS-Consolidation parameter indicates the measurement threshold when CSI-RSs are used for the analysis of the first handover condition.

In some implementations, when the SSBs are used for the analysis of the first handover condition and the UE 120 determines the first handover condition is met (such as the A3 event condition) , the UE 120 may determine whether the MeasObjectNR IE includes the nrofSS-BlocksToAverage parameter and the absThreshSS-BlocksConsolidation parameter. If the UE 120 determines that the MeasObjectNR IE includes the nrofSS-BlocksToAverage parameter and the absThreshSS-BlocksConsolidation parameter, the UE 120 may perform the second handover condition analysis described herein. However, if the UE 120 determines that the MeasObjectNR IE does not include the nrofSS-BlocksToAverage parameter or the absThreshSS-BlocksConsolidation parameter, the UE 120 may transmit the measurement report to the BS 410 without performing the second handover condition analysis.

In some implementations, when the CSI-RSs are used for the analysis of the first handover condition and the UE 120 determines the first handover condition is met (such as the A3 event condition) , the UE 120 may determine whether the MeasObjectNR IE includes the nrofCSI-RS-ResourcesToAverage parameter and the absThreshCSI-RS-Consolidation parameter. If the UE 120 determines that the MeasObjectNR IE includes the nrofCSI-RS-ResourcesToAverage parameter and the absThreshCSI-RS-Consolidation parameter, the UE 120 may perform the second handover condition analysis described herein. However, if the UE 120 determines that the MeasObjectNR IE does not include the nrofCSI-RS-ResourcesToAverage parameter and the absThreshCSI-RS-Consolidation parameter, the UE 120 may transmit the measurement report to the BS 410 without performing the second handover condition analysis.

Figure 5 shows an example message flow that shows a UE, a first BS of a 5G NR network, and a second BS of a 5G NR network configured to implement handover conditions for a handover measurement report. The message flow diagram 500 includes the UE 120, the BS 410, and the BS 411 that are described in Figure 4.

At 505, the UE 120 and the BS 410 may establish a wireless connection via the 5G NR network of a wireless communication network and exchange various types of messages, including data signals.

At 510, the BS 410 may transmit one or more reference signals to the UE 120. For example, the BS 410 may periodically transmit one or more reference signals to the UE 120. In some implementations, the BS 410 may transmit the one or more reference signals using CSI-RSs or SSBs.

At 515, the UE 120 may receive and process the one or more reference signals from the BS 410. For example, the UE 120 may receive one or more SSBs or one or more CSI-RS. In some implementations, the UE 120 may determine a first set of signal quality measurements based on the one or more reference signals. The signal quality measurements may be RSRP measurements, RSRQ measurements, or SINR measurements.

At 520, the BS 411 may transmit one or more reference signals to the wireless communication network, including the UE 120. For example, the BS 411 may periodically transmit one or more reference signals to the wireless communication network. In some implementations, the BS 411 may transmit the one or more reference signals using CSI-RSs or SSBs.

At 525, the UE 120 may detect the one or more reference signals from the BS 411 and may begin to process the one or more reference signals. For example, the UE 120 may detect one or more SSBs or one or more CSI-RS from the BS 411. In some implementations, the UE 120 may determine a second set of signal quality measurements based on the one or more reference signals. The signal quality measurements may be RSRP measurements, RSRQ measurements, or SINR measurements.

At 527, the UE 120 may determine whether a first handover condition is met. If the first handover condition is met, the UE 120 may determine whether a second handover condition is met, as described in Figure 4. If the second handover condition is met, the UE 120 may determine to prepare and transmit a measurement report (which also may be referred to as a handover measurement report) to the BS 410. If the first handover condition (such as the A3 event condition) is not met, then the UE 120 does not check whether the second handover condition is met and thus the UE 120 does not transmit a measurement report. Instead, the UE 120 may restart the handover conditions analysis process (as shown by the dashed line 529) after receiving different reference signals. If the second handover condition is not met, then the UE 120 does not transmit the measurement report, and the UE 120 may restart the handover conditions analysis process (as shown by the dashed line 529) after receiving different reference signals.

At 530, the UE 120 transmits the measurement report to the BS 410. The UE 120 may transmit the measurement report to the BS 410 after performing the handover conditions analysis process and determining that both the first and second handover conditions have been satisfied.

At 535, the BS 410 receives the measurement report from the UE 120 and determines to initiate a handover operation. The measurement report indicates that both the first and second handover conditions have been satisfied, and therefore triggers the BS 410 to perform the handover operation to handover the UE 120 from the BS 410 to the BS 411.

At 540, the BS 410 and the BS 411 exchange handover-related messaging to perform the handover operation to handover the UE 120 from the BS 410 to the BS 411.

At 545, 547, and 549, the BS 411 and the UE 120 exchange and process messages to establish a wireless connection via the 5G NR network and complete the handover operation.

At 550, after a wireless connection between the BS 411 and the UE 120 is established via the 5G NR network, the UE 120 and the BS 411 exchange various types of messages, including data signals.

Figure 6 depicts a flowchart 600 with example operations performed by an apparatus of a UE for implementing handover conditions for handover measurement reports in a wireless communication network.

At block 610, the apparatus of the UE may determine a first set of signal quality measurements from one or more reference signals obtained from a first BS of the wireless communication network. The first BS may have a wireless connection with the UE.

At block 620, the apparatus of the UE may determine a second set of signal quality measurements from one or more reference signals obtained from a second BS of the wireless communication network.

At block 630, the apparatus of the UE may determine that a first handover condition is met based on a comparison of the first set of signal quality measurements and the second set of signal quality measurements.

At block 640, the apparatus of the UE may determine whether a second handover condition is met based on a first signal quality measurement of the first set of signal quality measurements and a second signal quality measurement of the second set of signal quality measurements in response to determining the first handover condition is met. For example, the apparatus of the UE may determine the first signal quality measurement of the first set of signal quality measurements and the second signal quality measurement of the second set of signal quality measurements. The apparatus of the UE may determine whether the first signal quality measurement associated with the first BS is less than the second signal quality measurement associated with the second BS. The apparatus of the UE may determine that the second handover condition is met in response to determining the first signal quality measurement is less than the second signal quality measurement. In some implementations, the first signal quality measurement of the first set of signal quality measurements may be a first maximum signal quality measurement of the first set of signal quality measurements, and the second signal quality measurement of the second set of signal quality measurements may be a second maximum signal quality measurement of the second set of signal quality measurements. In some implementations, the apparatus of the UE may determine whether the first maximum signal quality measurement associated with the first BS is less than the second maximum signal quality measurement associated with the second BS. The apparatus of the UE may determine that the second handover condition is met in response to determining the first maximum signal quality measurement is less than the second maximum signal quality measurement.

At block 650, the apparatus of the UE may output a handover measurement report for transmission to the first BS in response to determining the second handover condition is met.

Figure 7 depicts a flowchart 700 with example operations performed by an apparatus of a first BS for performing a handover operation in a wireless communication network in response to receiving a handover measurement reports triggered based on handover conditions.

At block 710, the apparatus of the first BS may output one or more reference signals for transmission to a UE of the wireless communication network. The UE may have a wireless connection with the first BS.

At block 720, the apparatus of the first BS may obtain a handover measurement report from the UE after the transmission of the one or more reference signals from the first BS to the UE.

At block 730, the apparatus of the first BS may determine that a first handover condition is met based on the handover measurement report. The first handover condition may be indicative that a handover event was triggered at the UE based on a comparison of a first set of signal quality measurements associated with the first BS and a second set of signal quality measurements associated with a second BS of the wireless communication network.

At block 740, the apparatus of the first BS may determine that a second handover condition is met based on the handover measurement report. The second handover condition may be indicative that a first signal quality measurement of the first set of signal quality measurements is less than a second signal quality measurement of the second set of signal quality measurements. In some implementations, the first signal quality measurement of the first set of signal quality measurements may be a first maximum signal quality measurement of the first set of signal quality measurements, and the second signal quality measurement of the second set of signal quality measurements may be a second maximum signal quality measurement of the second set of signal quality measurements. The second handover condition may be indicative that the first maximum signal quality measurement is less than the second maximum signal quality measurement.

At block 750, the apparatus of the first BS may perform a handover of the UE from the first BS to the second BS in response to obtaining the handover measurement report.

Figure 8 shows a conceptual diagram of an example configuration message 800 and example configuration information element related to the handover conditions analysis and the handover measurement reports. For example, a base station (such as the BS 410 of Figure 4) may transmit the example configuration message 800 to a UE (such as the UE 120 of Figure 4) . In some implementations, the UE may transmit a similarly formatted reporting message (not shown) with some of the configuration settings described with reference to Figure 8. The configuration message 800 may include one or more indicators (or information elements (IEs) ) that may configure the UE to implement the handover conditions for the handover measurement reports. The configuration message 800 may include a frame header 824 and configuration data 810. The frame header 824 may indicate the type of configuration information or other frame control information. The configuration data 810 may include a variety of indicators or IEs 850. Figure 8 shows some example indicators or IEs 850.

In some implementations, the example indicators or IEs 850 may include a measurement report configuration IE 852 that indicates whether to perform signal quality measurements based on SSBs or CSI-RSs, and whether to use RSRP, RSRQ, or SINR for the signal quality measurements. The measurement report configuration IE 852, which may be referred to as a ReportConfigNR IE, may include an NR-RS-Type parameter that indicates whether to perform signal quality measurements based on SSBs or CSI-RSs, and a MeasTriggerQuantityOffset parameter that indicates whether to use RSRP, RSRQ, or SINR for the signal quality measurements. The example indicators or IEs 850 also may include a measurement configuration IE 854 that indicates the maximum number of signal quality measurements and the measurement threshold. For example, the measurement configuration IE 854, which also may be referred to as a MeasObjectNR IE, may include a nrofSS-BlocksToAverage parameter that indicates the maximum number of signal quality measurements to use for the averages, and an absThreshSS-BlocksConsolidation parameter that indicates the measurement threshold when SSBs are used for the analysis of the first handover condition. The MeasObjectNR IE also may include a nrofCSI-RS-ResourcesToAverage parameter that indicates the maximum number of signal quality measurements to use for the averages, and an absThreshCSI-RS-Consolidation parameter that indicates the measurement threshold when CSI-RSs are used for the analysis of the first handover condition.

Figure 9 shows a block diagram of an example wireless communication device 900. In some implementations, the wireless communication device 900 can be an example of a device or apparatus for use in a UE, such as the UE 120 described above with reference to Figure 4. In some implementations, the wireless communication device 900 can be an example of a device or apparatus for use in a BS, such as the BS 410 or the BS 411 described above with reference to Figure 4. The wireless communication device 900 is capable of transmitting (or outputting for transmission) and receiving wireless communications.

The wireless communication device 900 can be, or can include, a chip, system on chip (SoC) , chipset, package or device. The term “system-on-chip” (SoC) is used herein to refer to a set of interconnected electronic circuits typically, but not exclusively, including one or more processors, a memory, and one or more network interfaces. The SoC may include a variety of different types of processors and processor cores, such as a general purpose processor, a central processing unit (CPU) , a digital signal processor (DSP) , a graphics processing unit (GPU) , an accelerated processing unit (APU) , a sub-system processor, an auxiliary processor, a single-core processor, and a multicore processor. The SoC may further include other hardware and hardware combinations, such as a field programmable gate array (FPGA) , a configuration and status register (CSR) , an application-specific integrated circuit (ASIC) , other programmable logic device, discrete gate logic, transistor logic, registers, performance monitoring hardware, watchdog hardware, counters, and time references. SoCs may be integrated circuits (ICs) configured such that the components of the IC reside on the same substrate, such as a single piece of semiconductor material (such as, for example, silicon) .

The term “system in a package” (SIP) is used herein to refer to a single module or package that may contain multiple resources, computational units, cores and/or processors on two or more IC chips, substrates, or SoCs. For example, a SIP may include a single substrate on which multiple IC chips or semiconductor dies are stacked in a vertical configuration. Similarly, the SIP may include one or more multi-chip modules (MCMs) on which multiple ICs or semiconductor dies are packaged into a unifying substrate. A SIP also may include multiple independent SoCs coupled together via high speed communication circuitry and packaged in close proximity, such as on a single motherboard or in a single mobile communication device. The proximity of the SoCs facilitates high speed communications and the sharing of memory and resources.

The term “multicore processor” is used herein to refer to a single IC chip or chip package that contains two or more independent processing cores (for example a CPU core, IP core, GPU core, among other examples) configured to read and execute program instructions. An SoC may include multiple multicore processors, and each processor in an SoC may be referred to as a core. The term “multiprocessor” may be used herein to refer to a system or device that includes two or more processing units configured to read and execute program instructions.

The wireless communication device 900 may include one or more modems 902. In some implementations, the one or more modems 902 (collectively “the modem 902” ) may include a WWAN modem (for example, a 3GPP 4G LTE or 5G compliant modem) . In some implementations, the wireless communication device 900 also includes one or more radios 904 (collectively “the radio 904” ) . In some implementations, the wireless communication device 900 further includes one or more processors, processing blocks or processing elements 906 (collectively “the processor 906” ) and one or more memory blocks or elements 908 (collectively “the memory 908” ) .

The modem 902 can include an intelligent hardware block or device such as, for example, an application-specific integrated circuit (ASIC) among other possibilities. The modem 902 is generally configured to implement a PHY layer. For example, the modem 902 is configured to modulate packets and to output the modulated packets to the radio 904 for transmission over the wireless medium. The modem 902 is similarly configured to obtain modulated packets received by the radio 904 and to demodulate the packets to provide demodulated packets. In addition to a modulator and a demodulator, the modem 902 may further include digital signal processing (DSP) circuitry, automatic gain control (AGC) , a coder, a decoder, a multiplexer and a demultiplexer. For example, while in a transmission mode, data obtained from the processor 906 is provided to a coder, which encodes the data to provide encoded bits. The encoded bits are then mapped to points in a modulation constellation (using a selected MCS) to provide modulated symbols. The modulated symbols may then be mapped to a number NSS of spatial streams or a number NSTS of space-time streams. The modulated symbols in the respective spatial or space-time streams may then be multiplexed, transformed via an inverse fast Fourier transform (IFFT) block, and subsequently provided to the DSP circuitry for Tx windowing and filtering. The digital signals may then be provided to a digital-to-analog converter (DAC) . The resultant analog signals may then be provided to a frequency upconverter, and ultimately, the radio 904. In implementations involving beamforming, the modulated symbols in the respective spatial streams are precoded via a steering matrix prior to their provision to the IFFT block.

While in a reception mode, digital signals received from the radio 904 are provided to the DSP circuitry, which is configured to acquire a received signal, for example, by detecting the presence of the signal and estimating the initial timing and frequency offsets. The DSP circuitry is further configured to digitally condition the digital signals, for example, using channel (narrowband) filtering, analog impairment conditioning (such as correcting for I/Q imbalance) , and applying digital gain to ultimately obtain a narrowband signal. The output of the DSP circuitry may then be fed to the AGC, which is configured to use information extracted from the digital signals, for example, in one or more received training fields, to determine an appropriate gain. The output of the DSP circuitry also is coupled with the demodulator, which is configured to extract modulated symbols from the signal and, for example, compute the logarithm likelihood ratios (LLRs) for each bit position of each subcarrier in each spatial stream. The demodulator is coupled with the decoder, which may be configured to process the LLRs to provide decoded bits. The decoded bits from all of the spatial streams are then fed to the demultiplexer for demultiplexing. The demultiplexed bits may then be descrambled and provided to the MAC layer (the processor 906) for processing, evaluation, or interpretation.

The radio 904 generally includes at least one radio frequency (RF) transmitter (or “transmitter chain” ) and at least one RF receiver (or “receiver chain” ) , which may be combined into one or more transceivers. For example, the RF transmitters and receivers may include various DSP circuitry including at least one power amplifier (PA) and at least one low-noise amplifier (LNA) , respectively. The RF transmitters and receivers may, in turn, be coupled to one or more antennas. For example, in some implementations, the wireless communication device 900 can include, or be coupled with, multiple transmit antennas (each with a corresponding transmit chain) and multiple receive antennas (each with a corresponding receive chain) . The symbols output from the modem 902 are provided to the radio 904, which then transmits the symbols via the coupled antennas. Similarly, symbols received via the antennas are obtained by the radio 904, which then provides the symbols to the modem 902. In some implementations, the radio 904 may include one or more network interfaces (which also may be referred to as “interfaces” ) . For example, a first interface of the radio 904 may be used to obtain wireless communications, and a second interface of the radio 904 may be used to output wireless communications for transmission.

The processor 906 can include an intelligent hardware block or device such as, for example, a processing core, a processing block, a central processing unit (CPU) , a microprocessor, a microcontroller, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a programmable logic device (PLD) such as a field programmable gate array (FPGA) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor 906 processes information received through the radio 904 and the modem 902, and processes information to be output through the modem 902 and the radio 904 for transmission through the wireless medium. In some implementations, the processor 906 may generally control the modem 902 to cause the modem to perform various operations described above.

The memory 908 can include tangible storage media such as random-access memory (RAM) or read-only memory (ROM) , or combinations thereof. The memory 908 also can store non-transitory processor-or computer-executable software (SW) code containing instructions that, when executed by the processor 906, cause the processor to perform various operations described herein for wireless communication, including the generation, transmission, reception and interpretation of MPDUs, frames or packets. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein, can be implemented as one or more modules of one or more computer programs.

Figures 1–9 and the operations described herein are examples meant to aid in understanding example implementations and should not be used to limit the potential implementations or limit the scope of the claims. Some implementations may perform additional operations, fewer operations, operations in parallel or in a different order, and some operations differently.

The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, or a combination of hardware and software. As used herein, the phrase “based on” is intended to be broadly construed to mean “based at least in part on. ”

Some aspects are described herein in connection with thresholds. As used herein, satisfying a threshold may refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, or the like.

As used herein, a phrase referring to “at least one of” or “one or more of” a list of items refers to any combination of those items, including single members. For example, “at least one of: a, b, or c” is intended to cover the possibilities of: a only, b only, c only, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a and b and c.

The various illustrative components, logic, logical blocks, modules, circuits, operations and algorithm processes described in connection with the implementations disclosed herein may be implemented as electronic hardware, firmware, software, or combinations of hardware, firmware or software, including the structures disclosed in this specification and the structural equivalents thereof. The interchangeability of hardware, firmware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and processes described above. Whether such functionality is implemented in hardware, firmware or software depends upon the particular application and design constraints imposed on the overall system.

The hardware and data processing apparatus used to implement the various illustrative components, logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single-or multi-chip processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device (PLD) , discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular processes, operations and methods may be performed by circuitry that is specific to a given function.

As described above, in some aspects implementations of the subject matter described in this specification can be implemented as software. For example, various functions of components disclosed herein, or various blocks or steps of a method, operation, process or algorithm disclosed herein can be implemented as one or more modules of one or more computer programs. Such computer programs can include non-transitory processor-or computer-executable instructions encoded on one or more tangible processor-or computer-readable storage media for execution by, or to control the operation of, data processing apparatus including the components of the devices described herein. By way of example, and not limitation, such storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store program code in the form of instructions or data structures. Combinations of the above should also be included within the scope of storage media.

Various modifications to the implementations described in this disclosure may be readily apparent to persons having ordinary skill in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein.

Additionally, various features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable subcombination. As such, although features may be described above as acting in particular combinations, and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one or more example processes in the form of a flowchart or flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In some circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

Claims

A method for wireless communication performed by an apparatus of a user equipment (UE) , comprising:

determining a first set of signal quality measurements from one or more reference signals obtained from a first base station (BS) of a wireless communication network, the first BS having a wireless connection with the UE;

determining a second set of signal quality measurements from one or more reference signals obtained from a second BS of the wireless communication network;

determining that a first handover condition is met based on a comparison of the first set of signal quality measurements and the second set of signal quality measurements;

determining whether a second handover condition is met based on a first signal quality measurement of the first set of signal quality measurements and a second signal quality measurement of the second set of signal quality measurements in response to determining the first handover condition is met; and

outputting a handover measurement report for transmission to the first BS in response to determining the second handover condition is met.
The method of claim 1, wherein the wireless communication network includes a 5G New Radio (NR) network.
The method of claim 1, wherein determining whether the second handover condition is met further comprises:

determining the first signal quality measurement of the first set of signal quality measurements associated with the first BS and the second signal quality measurement of the second set of signal quality measurements associated with the second BS;

determining whether the first signal quality measurement associated with the first BS is less than the second signal quality measurement associated with the second BS; and

determining that the second handover condition is met in response to determining the first signal quality measurement is less than the second signal quality measurement.
The method of claim 1, wherein

the first signal quality measurement of the first set of signal quality measurements is a first maximum signal quality measurement of the first set of signal quality measurements, and

the second signal quality measurement of the second set of signal quality measurements is a second maximum signal quality measurement of the second set of signal quality measurements.
The method of claim 4, wherein determining whether the second handover condition is met further comprises:

determining the first maximum signal quality measurement of the first set of signal quality measurements associated with the first BS and the second maximum signal quality measurement of the second set of signal quality measurements associated with the second BS;

determining whether the first maximum signal quality measurement associated with the first BS is less than the second maximum signal quality measurement associated with the second BS; and

determining that the second handover condition is met in response to determining the first maximum signal quality measurement is less than the second maximum signal quality measurement.
The method of claim 5, wherein determining whether the second handover condition is met further comprises:

determining that the second handover condition is not met in response to determining the first maximum signal quality measurement is greater than or equal to the second maximum signal quality measurement; and

determining not to transmit the handover measurement report to the first BS in response to determining the second handover condition is not met.
The method of claim 1, wherein determining that the first handover condition is met based on the comparison of the first set of signal quality measurements and the second set of signal quality measurements further comprises:

determining whether a handover event has been triggered based on the first set of signal quality measurements and the second set of signal quality measurements,

wherein determining the first handover condition is met is in response to determining the handover event has been triggered based on the first set of signal quality measurements and the second set of signal quality measurements.
The method of claim 1, wherein determining that the first handover condition is met based on the comparison of the first set of signal quality measurements and the second set of signal quality measurements further comprises:

determining a first average of the first set of signal quality measurements associated with the first BS and a second average of the second set of signal quality measurements associated with the second BS; and

determining whether a handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements,

wherein determining the first handover condition is met is in response to determining the handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements.
The method of claim 8, wherein the handover event is an A3 event, and the first handover condition is an A3 event condition or a handover event measurement report trigger condition.
The method of claim 8, further comprising:

determining the first handover condition is not met in response to determining the handover event has not been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements.
The method of claim 1, wherein

the first set of signal quality measurements determined from one or more reference signals obtained from the first BS are reference signal received power (RSRP) measurements, reference signal received quality (RSRQ) measurements, or signal-to-interference-plus-noise ratio (SINR) measurements determined from one or more synchronized signal block (SSB) signals obtained from the first BS; and

the second set of signal quality measurements determined from one or more reference signals obtained from the second BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more SSB signals obtained from the second BS.
The method of claim 1, wherein

the first set of signal quality measurements determined from one or more reference signals obtained from the first BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more channel state information reference signals (CSI-RSs) obtained from the first BS; and

the second set of signal quality measurements determined from one or more reference signals obtained from the second BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more CSI-RSs obtained from the second BS.
The method of claim 1, wherein the first set of signal quality measurements and the second set of signal quality measurements are RSRP measurements, RSRQ measurements, or SINR measurements, further comprising:

determining whether to perform the first set of signal quality measurements and the second set of signal quality measurements using RSRP measurements, RSRQ measurements, or SINR measurements based on a measurement report configuration information element (IE) obtained from the first BS.
A method for wireless communication performed by an apparatus of a first base station (BS) , comprising:

outputting one or more reference signals for transmission to a user equipment (UE) of a wireless communication network, the UE having a wireless connection with the first BS;

obtaining a handover measurement report from the UE after the transmission of the one or more reference signals from the first BS to the UE;

determining that a first handover condition is met based on the handover measurement report, the first handover condition being indicative that a handover event was triggered at the UE based on a comparison of a first set of signal quality measurements associated with the first BS and a second set of signal quality measurements associated with a second BS of the wireless communication network;

determining that a second handover condition is met based on the handover measurement report, the second handover condition being indicative that a first signal quality measurement of the first set of signal quality measurements is less than a second signal quality measurement of the second set of signal quality measurements; and

performing a handover of the UE from the first BS to the second BS in response to obtaining the handover measurement report.
The method of claim 14, wherein the wireless communication network includes a 5G New Radio (NR) network.
The method of claim 14, wherein

the first signal quality measurement of the first set of signal quality measurements is a first maximum signal quality measurement of the first set of signal quality measurements,

the second signal quality measurement of the second set of signal quality measurements is a second maximum signal quality measurement of the second set of signal quality measurements, and

the second handover condition being indicative that the first maximum signal quality measurement is less than the second maximum signal quality measurement.
The method of claim 14, wherein the handover event is triggered at the UE based on a comparison of a first average of the first set of signal quality measurements and a second average of the second set of signal quality measurements.
The method of claim 14, wherein the handover event is an A3 event, and the first handover condition is an A3 event condition or a handover event measurement report trigger condition.
The method of claim 14, wherein outputting the one or more reference signals for transmission to the UE further comprises:

outputting one or more synchronized signal block (SSB) signals for transmission to the UE,

wherein the first set of signal quality measurements are reference signal received power (RSRP) measurements, reference signal received quality (RSRQ) measurements, or signal-to-interference-plus-noise ratio (SINR) measurements determined by the UE from the one or more SSB signals obtained from the first BS, and

the second set of signal quality measurements are RSRP measurements, RSRQ measurements, or SINR measurements determined by the UE from one or more SSB signals obtained from the second BS.
The method of claim 14, wherein outputting the one or more reference signals for transmission to the UE further comprises:

outputting one or more channel state information reference signals (CSI-RSs) for transmission to the UE,

wherein the first set of signal quality measurements are RSRP measurements, RSRQ measurements, or SINR measurements determined by the UE from the one or more CSI-RSs obtained from the first BS, and

the second set of signal quality measurements are RSRP measurements, RSRQ measurements, or SINR measurements determined by the UE from one or more CSI-RSs obtained from the second BS.
An apparatus of a user equipment (UE) for wireless communication, comprising: one or more processors configured to:

determine a first set of signal quality measurements from one or more reference signals obtained from a first base station (BS) of a wireless communication network, the first BS having a wireless connection with the UE;

determine a second set of signal quality measurements from one or more reference signals obtained from a second BS of the wireless communication network;

determine that a first handover condition is met based on a comparison of the first set of signal quality measurements and the second set of signal quality measurements; and

determine whether a second handover condition is met based on a first signal quality measurement of the first set of signal quality measurements and a second signal quality measurement of the second set of signal quality measurements in response to a determination that the first handover condition is met; and

an interface configured to output a handover measurement report for transmission to the first BS in response to a determination that the second handover condition is met.
The apparatus of claim 21, wherein the one or more processors are further configured to:

determine the first signal quality measurement of the first set of signal quality measurements associated with the first BS and the second signal quality measurement of the second set of signal quality measurements associated with the second BS;

determine whether the first signal quality measurement associated with the first BS is less than the second signal quality measurement associated with the second BS; and

determine that the second handover condition is met in response to determining the first signal quality measurement is less than the second signal quality measurement.
The apparatus of claim 21, wherein

the first signal quality measurement of the first set of signal quality measurements is a first maximum signal quality measurement of the first set of signal quality measurements, and

the second signal quality measurement of the second set of signal quality measurements is a second maximum signal quality measurement of the second set of signal quality measurements.
The apparatus of claim 23, wherein the one or more processors are further configured to:

determine the first maximum signal quality measurement of the first set of signal quality measurements associated with the first BS and the second first maximum signal quality measurement of the second set of signal quality measurements associated with the second BS;

determine whether the first maximum signal quality measurement associated with the first BS is less than the second maximum signal quality measurement associated with the second BS; and

determine that the second handover condition is met in response to a determination that the first maximum signal quality measurement is less than the second maximum signal quality measurement.
The apparatus of claim 21, wherein the one or more processors are further configured to:

determine a first average of the first set of signal quality measurements associated with the first BS and a second average of the second set of signal quality measurements associated with the second BS;

determine whether a handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements; and

determine that the first handover condition is met in response to a determination that the handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements.
The apparatus of claim 25, wherein the handover event is an A3 event, and the first handover condition is an A3 event condition or a handover event measurement report trigger condition.
The apparatus of claim 21, wherein

the first set of signal quality measurements determined from one or more reference signals obtained from the first BS are reference signal received power (RSRP) measurements, reference signal received quality (RSRQ) measurements, or signal-to-interference-plus-noise ratio (SINR) measurements determined from one or more synchronized signal block (SSB) signals obtained from the first BS; and

the second set of signal quality measurements determined from one or more reference signals obtained from the second BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more SSB signals obtained from the second BS.
The apparatus of claim 21, wherein

the first set of signal quality measurements determined from one or more reference signals obtained from the first BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more channel state information reference signals (CSI-RSs) obtained from the first BS; and

the second set of signal quality measurements determined from one or more reference signals obtained from the second BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more CSI-RSs obtained from the second BS.
The apparatus of claim 21, wherein the one or more processors are further configured to:

determine whether to perform the first set of signal quality measurements and the second set of signal quality measurements using RSRP measurements, RSRQ measurements, or SINR measurements based on a measurement report configuration information element (IE) obtained from the first BS.
An apparatus for wireless communication, comprising:

means for determining a first set of signal quality measurements from one or more reference signals obtained from a first base station (BS) of a wireless communication network, the first BS having a wireless connection with the apparatus;

means for determining a second set of signal quality measurements from one or more reference signals obtained from a second BS of the wireless communication network;

means for determining that a first handover condition is met based on a comparison of the first set of signal quality measurements and the second set of signal quality measurements;

means for determining whether a second handover condition is met based on a first signal quality measurement of the first set of signal quality measurements and a second signal quality measurement of the second set of signal quality measurements in response to a determination that the first handover condition is met; and

means for outputting a handover measurement report for transmission to the first BS in response to a determination that the second handover condition is met.
The apparatus of claim 30, further comprising:

means for determining the first signal quality measurement of the first set of signal quality measurements associated with the first BS and the second signal quality measurement of the second set of signal quality measurements associated with the second BS;

means for determining whether the first signal quality measurement associated with the first BS is less than the second signal quality measurement associated with the second BS; and

means for determining that the second handover condition is met in response to determining the first signal quality measurement is less than the second signal quality measurement.
The apparatus of claim 30, wherein

the first signal quality measurement of the first set of signal quality measurements is a first maximum signal quality measurement of the first set of signal quality measurements, and

the second signal quality measurement of the second set of signal quality measurements is a second maximum signal quality measurement of the second set of signal quality measurements.
The apparatus of claim 32, further comprises:

means for determining the first maximum signal quality measurement of the first set of signal quality measurements associated with the first BS and the second first maximum signal quality measurement of the second set of signal quality measurements associated with the second BS;

means for determining whether the first maximum signal quality measurement associated with the first BS is less than the second maximum signal quality measurement associated with the second BS; and

means for determining that the second handover condition is met in response to a determination that the first maximum signal quality measurement is less than the second maximum signal quality measurement.
The apparatus of claim 30, further comprising:

means for determining a first average of the first set of signal quality measurements associated with the first BS and a second average of the second set of signal quality measurements associated with the second BS;

means for determining whether a handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements; and

means for determining that the first handover condition is met in response to a determination that the handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements.
The apparatus of claim 34, wherein the handover event is an A3 event, and the first handover condition is an A3 event condition or a handover event measurement report trigger condition.
The apparatus of claim 30, wherein

the first set of signal quality measurements determined from one or more reference signals obtained from the first BS are reference signal received power (RSRP) measurements, reference signal received quality (RSRQ) measurements, or signal-to-interference-plus-noise ratio (SINR) measurements determined from one or more synchronized signal block (SSB) signals obtained from the first BS; and

the second set of signal quality measurements determined from one or more reference signals obtained from the second BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more SSB signals obtained from the second BS.
The apparatus of claim 30, wherein

the first set of signal quality measurements determined from one or more reference signals obtained from the first BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more channel state information reference signals (CSI-RSs) obtained from the first BS; and

the second set of signal quality measurements determined from one or more reference signals obtained from the second BS are RSRP measurements, RSRQ measurements, or SINR measurements determined from one or more CSI-RSs obtained from the second BS.
An apparatus of a first base station (BS) for wireless communication, comprising:

a first interface configured to output one or more reference signals for transmission to a user equipment (UE) of a wireless communication network, the UE having a wireless connection with the first BS;

a second interface configured to obtain a handover measurement report from the UE after the output of the one or more reference signals for transmission from the first BS to the UE; and

one or more processors configured to:

determine that a first handover condition is met based on the handover measurement report, the first handover condition being indicative that a handover event was triggered at the UE based on a comparison of a first set of signal quality measurements associated with the first BS and a second set of signal quality measurements associated with a second BS of the wireless communication network;

determine that a second handover condition is met based on the handover measurement report, the second handover condition being indicative that a first signal quality measurement of the first set of signal quality measurements is less than a second signal quality measurement of the second set of signal quality measurements; and

perform a handover of the UE from the first BS to the second BS in response to obtainment of the handover measurement report.
The apparatus of claim 38, wherein

the first signal quality measurement of the first set of signal quality measurements is a first maximum signal quality measurement of the first set of signal quality measurements,

the second signal quality measurement of the second set of signal quality measurements is a second maximum signal quality measurement of the second set of signal quality measurements, and

the second handover condition being indicative that the first maximum signal quality measurement is less than the second maximum signal quality measurement.
The apparatus of claim 38, wherein the handover event is triggered at the UE based on a comparison of a first average of the first set of signal quality measurements and a second average of the second set of signal quality measurements.
A non-transitory computer-readable medium having stored therein instructions which, when executed by a processor of a user equipment (UE) , cause the UE to:

determine a first set of signal quality measurements from one or more reference signals obtained from a first base station (BS) of a wireless communication network, the first BS having a wireless connection with the UE;

determine a second set of signal quality measurements from one or more reference signals obtained from a second BS of the wireless communication network;

determine that a first handover condition is met based on a comparison of the first set of signal quality measurements and the second set of signal quality measurements;

determine whether a second handover condition is met based on a first signal quality measurement of the first set of signal quality measurements and a second signal quality measurement of the second set of signal quality measurements in response to a determination that the first handover condition is met; and

output a handover measurement report for transmission to the first BS in response to a determination that the second handover condition is met.
The non-transitory computer-readable medium of claim 41, wherein the instructions, when executed by the processor of the UE, further cause the UE to:

determine the first signal quality measurement of the first set of signal quality measurements associated with the first BS and the second signal quality measurement of the second set of signal quality measurements associated with the second BS;

determine whether the first signal quality measurement associated with the first BS is less than the second signal quality measurement associated with the second BS; and

determine that the second handover condition is met in response to a determination that the first signal quality measurement is less than the second signal quality measurement.
The non-transitory computer-readable medium of claim 41, wherein

the first signal quality measurement of the first set of signal quality measurements is a first maximum signal quality measurement of the first set of signal quality measurements, and

the second signal quality measurement of the second set of signal quality measurements is a second maximum signal quality measurement of the second set of signal quality measurements.
The non-transitory computer-readable medium of claim 43, wherein the instructions, when executed by the processor of the UE, further cause the UE to:

determine the first maximum signal quality measurement of the first set of signal quality measurements associated with the first BS and the second maximum signal quality measurement of the second set of signal quality measurements associated with the second BS;

determine whether the first maximum signal quality measurement associated with the first BS is less than the second maximum signal quality measurement associated with the second BS; and

determine that the second handover condition is met in response to a determination that the first maximum signal quality measurement is less than the second maximum signal quality measurement.
The non-transitory computer-readable medium of claim 41, wherein the instructions, when executed by the processor of the UE, further cause the UE to:

determine a first average of the first set of signal quality measurements associated with the first BS and a second average of the second set of signal quality measurements associated with the second BS;

determine whether a handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements; and

determine that the first handover condition is met in response to a determination that the handover event has been triggered based on the first average of the first set of signal quality measurements and the second average of the second set of signal quality measurements.