WO2018133036A1

WO2018133036A1 - Methods, base stations, and user equipments for measurement before handover

Info

Publication number: WO2018133036A1
Application number: PCT/CN2017/071956
Authority: WO
Inventors: Lu Yang; Xiang Chen; Eddy Chiu
Original assignee: Huizhou Tcl Mobile Communication Co., Ltd
Priority date: 2017-01-20
Filing date: 2017-01-20
Publication date: 2018-07-26
Also published as: CN109076408A

Abstract

Methods for measurement before handover are disclosed. A method includes: determining, by a base station, whether a User Equipment (UE) meets a measurement triggering condition； when the UE meets the measurement triggering condition, transmitting, by the base station, a measurement notification and information of a first beam set to the UE, so that the UE measures beams in the first beam set before handover, wherein all beams in the first beam set belong to a neighbor cell. Associated base stations and UEs are also disclosed.

Description

METHODS, BASE STATIONS, AND USER EQUIPMENTS FOR MEASUREMENT BEFORE HANDOVER

TECHNICAL FIELD

Embodiments of the present disclosure relate generally to communications, and in particular relate to methods, base stations, and User Equipments (UEs) for measurement before handover.

BACKGROUND

In conventional LTE/LTE-A system, the operations during mobility, including cell reselection and handover, are based on the measurement results of the reference signal, which is transmitted through an omni-directional (or wide) beam covering the whole cell (or sector) , and the UEs served by the same cell measure the same reference signal. When the measured quality (RSRP, Reference Signal Received Power) is lower than a certain threshold, the UE is triggered to measure the neighbor cell for handover.

As for the NR system, it is envisaged to operate over frequency ranges up to 100GHz, which is considered as an important technology for capacity improvement. However, here comes the challenges of fragile radio link and high penetration loss especially for the high frequency scenario, and hence beamforming becomes an essential technique to address those problems. As a result, beams will play an inevitable role and the UE needs to measure different reference signals corresponding to different beams for mobility even in the same cell.

If we directly apply conventional LTE/LTE-A measurement triggering scheme for NR, where different beams provide directional services for different spots within a cell coverage， the UE at the cell edge may still be served by directional beam with good quality without starting measurement. Moreover, the measurement triggering point based on the crosspoint of the RSRP curve and the measurement triggering threshold line is no longer suitable for NR system, since the RSRP curve of the serving cell may have more than one crosspoints with the measurement triggering threshold line, with the RSRP curve of each TRP fluctuating itself due to beamforming. In addition, the UE needs to measure all the beams of the neighbor cells for handover. It is obvious that the number of beams for UE to measure will become extremely large in NR, leading to a huge measurement overhead for the UE.

SUMMARY

In view of the above, embodiments of the present disclosure provide methods, base stations, and UEs for measurement before handover, aiming at more accurate triggering point of measurement before handover.

There is provided a method for measurement before handover that comprises: determining, by a base station, whether a User Equipment (UE) meets a measurement triggering condition； when the UE meets the measurement triggering condition, transmitting, by the base station, a measurement notification and information of a first beam set to the UE, so that the UE measures beams in the first beam set before handover, wherein all beams in the first beam set belong to a neighbor cell.

There is also provided a method for measurement before handover that comprises: receiving, by a User Equipment (UE) , a measurement notification and information of a first beam set transmitted from a base station of a serving cell when the base station of the serving cell determining that the UE meets the measurement triggering condition, wherein all beams in the first beam set belong to a neighbor cell； measuring, by the UE, beams in the first beam set before handover.

There is also provided a base station that comprises: a determination module configured to determine whether a User Equipment (UE) meets a measurement triggering condition； a transmission module configured to transmit a measurement notification and information of a first beam set to the UE when the UE meets the measurement triggering condition, so that the UE measures beams in the first beam set before handover, wherein all beams in the first beam set belong to a neighbor cell.

There is also provided a UE that comprises: a receiving module configured to receive a measurement notification and information of a first beam set transmitted from a base station of a serving cell when the base station of the serving cell determining that the UE meets the measurement triggering condition, wherein all beams in the first beam set belong to a neighbor cell； a measurement module configured to measure beams in the first beam set before handover.

There is also provided a base station that comprises: a processor and a transceiver connected to the processor； the processor being configured to: determine whether a User Equipment (UE) meets a measurement triggering condition； and transmit via the transceiver a measurement notification and information of a first beam set to the UE when the UE meets the measurement triggering condition, so that the UE measures beams in the first beam set before handover, wherein all beams in the first beam set belong to a neighbor cell.

There is also provided a UE that comprises: a processor and a communication circuit connected to the processor； the processor being configured to: receive via the communication circuit a measurement notification and information of a first beam set transmitted from a base station of a serving cell when the base station of the serving cell determining that the UE meets the measurement triggering condition, wherein all beams in the first beam set belong to a neighbor cell； and measure beams in the first beam set before handover.

Advantages of the present disclosure may follow. Instead of conventional purely quality-based measurement, the base station may determine whether the UE meets the measurement triggering condition, and inform the UE of performing measurement before handover when the UE meets the measurement triggering condition. UE’s incorrect measurement triggering caused by the beamforming technique may be avoided and hence selection of triggering point of measurement before handover is more accurate. In addition, when the number of beams in the first beam set is less than the total number of beams in the neighbor cell, number of beam candidates for UE to measure before handover is reduced and thus the measurement overhead of UE is reduced, which helps to reduce measurement delay, measurement report failure and handover failure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart illustrating a first embodiment of a method for measurement before handover according to the disclosure.

FIG. 2 is a flowchart illustrating a second embodiment of a method for measurement before handover according to the disclosure.

FIG. 3 is a flowchart illustrating a third embodiment of a method for measurement before handover according to the disclosure.

FIG. 4 is a flowchart illustrating a fourth embodiment of a method for measurement before handover according to the disclosure.

FIG. 5 is a flowchart illustrating a fifth embodiment of a method for measurement before handover according to the disclosure.

FIG. 6 is a flowchart illustrating a sixth embodiment of a method for measurement before handover according to the disclosure.

FIG. 7 shows an example of beams and TRPs in an embodiment of a method for measurement before handover according to the disclosure.

FIG. 8 is a flowchart illustrating a seventh embodiment of a method for measurement before handover according to the disclosure.

FIG. 9 is a block diagram of a first embodiment of a base station according to the disclosure.

FIG. 10 shows a block diagram of a second embodiment of a base station according to the disclosure.

FIG. 11 shows a block diagram of a third embodiment of a base station according to the disclosure.

FIG. 12 shows a block diagram of a first embodiment of a UE according to the disclosure.

FIG. 13 shows a block diagram of a second embodiment of a UE according to the disclosure.

This disclosure includes references to “one embodiment, ” “a particular embodiment, ” “some embodiments, ” “various embodiments, ” or “an embodiment. ” The appearances of the phrases “in one embodiment, ” “in a particular embodiment, ” “in some embodiments, ” “in various embodiments, ” or “in an embodiment, ” do not necessarily refer to the same embodiment. Particular features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure.

Various modules, units, circuits, or other components may be described or claimed as “configured to” perform a task or tasks. In such contexts, “configured to” is used to connote structure by indicating that the modules/units/circuits/components include structure (e.g., circuitry) that performs those task or tasks during operation. As such, the modules/units/circuits/components can be said to be configured to perform the task even when the specified module/unit/circuit/component is not currently operational (e.g., is not on) . The modules/units/circuits/components used with the “'configured to” language include hardware—for example, circuits, memory storing program instructions executable to implement the operation, etc. Reciting that a module/unit/circuit/component is “configured to” perform one or more tasks is expressly intended not to invoke 35 U.S.C. §112 (f) , for that module/unit/circuit/component. Additionally, “configured to” can include a generic structure (e.g., generic circuitry) that is manipulated by software and/or firmware (e.g., an FPGA or a general-purpose processor executing software) to operate in a manner that is capable of performing the task (s) at issue. “Configured to” may also include adapting a manufacturing process (e.g., a semiconductor fabrication facility) to fabricate devices (e.g., integrated circuits) that are adapted to implement or perform one or more tasks.

As used herein, the term “based on” describes one or more factors that affect a determination. This term does not foreclose additional factors that may affect the determination. That is, a determination may be solely based on those factors or based, at least in part, on those factors. Consider the phrase “determine A based on B. ” While in this case, B is a factor affects the determination of A, such a phrase does not foreclose the determination of A from also being based on C. In other instances, A may be determined based solely on B.

DETAILED DESCRIPTION

Referring to FIG. 1 a flowchart is depicted illustrating a first embodiment of a method for measurement before handover according to the disclosure. The method may be implemented on a base station. The base station may be connected to a core network and may perform wireless communications with a plurality of UEs to provide communications coverage for the associated geographical area. The base station may comprise, but not limited to, macro base stations, micro base stations, or pico base stations. In various embodiments, a base station can also be interchangeably referred to as a wireless base station, access point, Node B, evolved Node B (eNodeB or eNB) , gNB, etc. . For purposes of illustration, the method is illustrated as being sequential. However, portions of the method may be performed in other orders or in parallel (e.g., simultaneously) . The method may comprise the following blocks.

In S11, the base station may determine whether a User Equipment (UE) meets measurement triggering condition.

Typically, the measurement triggering condition may comprise the UE being high mobility or the UE being at the edge of serving cell (i.e. the cell controlled by the base station) . If the UE meets any one of them, the measurement triggering condition is satisfied.

The UE may be divided into high-mobility UE and normal-mobility UE according to its moving speed. No matter which UE when at the edge of serving cell, it may move to neighbor cell, so that it may need to perform measurement before handover to prepare for handover. In addition, for the high-mobility UE, if it is only informed of measurement before handover at serving cell edge, it may leave the coverage of the serving cell before handover procedure is finished, leading to problems such as measurement delay, measurement report failure and handover failure. To avoid this condition, the base station may determine that the UE needs to perform measurement before handover right after determining that the UE is high mobility.

In S12, the base station may transmit a measurement notification and information of a first beam set to the UE when the UE meets the measurement triggering condition.

The UE may respond to the measurement notification and measures beams in the first beam set before handover according to information of the first beam set. The information of the first beam set may comprise time/frequency resources of the beams in the first beam set, so that the UE can measure the beams in the first beam set accordingly.

The serving cell may have multiple neighbor cells, each neighbor cell may correspond to a first beam set, and all beams in each first beam set belong to the corresponding neighbor cell. The base station may transmit information of multiple first beam sets corresponding to partial or all neighbor cells to the UE.

For each neighbor cell, the number of beams in the corresponding first beam set may be less than the total number of beams in the neighbor cell. Compared with prior art, number of beam candidates for UE to measure before handover may be reduced and thus the measurement overhead may be reduced, which may help to reduce measurement delay, measurement report failure and handover failure. Beams in the first beam set may be beams with high probability of being changed to, which are selected by the base station of the neighbor cell and/or the base station of serving cell according to the UE’s possible location range in handover procedure.

In one embodiment, for location ranges of the same size, the higher carrier frequency of the neighbor cell is, the smaller the serving range of beam in the neighbor cell is to compensate for the larger pathloss of the higher carrier frequency, and the more the number of beams in the first beam set is, i.e., the number of beams in the first beam set has a positive correlation with carrier frequency of the neighbor cell.

Of course, the number of beams in the first beam set may be equal to the total number of beams in the neighbor cell.

According to the above embodiment, instead of conventional purely quality-based measurement, the base station may determine whether the UE meets the measurement triggering condition, and inform the UE of measurement information before handover when the UE meets the measurement triggering condition. UE’s incorrect measurement triggering caused by beamforming technique may be avoided and hence selection of triggering point of measurement before handover is more accurate.

Referring now to FIG. 2, a flowchart is depicted illustrating a second embodiment of the method for measurement before handover according to the disclosure, which is based on the first embodiment of the measurement before handover method and in which the block S11 further comprises the following blocks.

In S111, the base station may determine whether the UE is high mobility.

If the UE is high mobility, jump to block S113； if the UE is not high mobility (i.e. the UE is normal mobility) , jump to block S112.

The base station may obtain multiple locations of the UE with timestamps, calculate moving speed of the UE accordingly, and then compare the moving speed of the UE with a predetermined speed threshold. When the moving speed of the UE is faster than the predetermined speed threshold, the base station may determine that the UE is high mobility. Since the calculation of the moving speed is complex, the latency of determination is relatively high. In addition, the base station usually obtains the locations of the UE according to the beam currently connected to UE with limited accuracy. Therefore error of the calculated moving speed is relatively large and may affect accuracy of the determination.

The base station may determine whether the UE is high mobility according to the number of beam switching in a judging duration， which will be described in greater detail in the following third embodiment. In other embodiments, the serving cell may comprise multiple transmission and reception points (TRPs) , the number of the TRPs may be large and relatively evenly distributed, and the base station can determine whether the UE is high mobility according to the number of the UE’s TRP switching. TRP can also be referred to as transmission point (TP) or Radio Remote Head (RRH) .

In S112, the base station may determine whether the UE is at serving cell edge.

If the UE is at serving cell edge, jump to block S113； if the UE is not at serving cell edge, jump to block S114.

The base station may determine whether the UE is at serving cell edge according to the beam connected, which will be described in greater detail in the following forth embodiment. In other embodiments, the base station may use location of the UE or TRP connected to the UE for determination.

In S113, the base station may determine that the UE meets the measurement triggering condition.

Jump to the following blocks.

In S114, the base station may determine that the UE does not meet the measurement triggering condition.

The process terminates. The base station of serving cell may continue tracking the UE’s location.

Referring now to FIG. 3, a flowchart is depicted illustrating a third embodiment of the method for measurement before handover according to the disclosure, which is based on the second embodiment of the measurement before handover method and in which the block S111 further comprises the following block.

In S1110, the base station may determine whether the number of beam switching in a judging duration is greater than a predetermined threshold.

The starting point of the judging duration may be when the UE completing initial access after entering the serving cell. The UE may need to switch between different beams within the serving cell for mobility. Typically, beams in the serving cell may be relatively evenly distributed, length of the judging duration may be fixed, and the number of beam switching in the judging duration may be directly proportional to the moving speed of the UE. Based on the beam distribution within the serving cell, the predetermined speed threshold can be converted to the predetermined threshold of the number of beam switching. After the judging duration, the base station may determine whether the UE is high mobility according the comparison result of the number of beam switch and the predetermined threshold. If the number of beam switch is greater than the predetermined threshold, the UE is high mobility. If the number of beam switch of UE is less than or equal to the predetermined threshold, the UE is not high mobility.

Referring now to FIG. 4, a flowchart is depicted illustrating a forth embodiment of the method for measurement before handover according to the disclosure, which is based on the second embodiment of the measurement before handover method and in which the block S112 further comprises the following block.

In S1120, the base station may determine whether the UE is connected to a serving cell edge beam.

A serving cell edge beam is a beam with serving range at the edge of serving cell. If the UE is connected to a serving cell edge beam, the UE is at serving cell edge. If the UE is not connected to a serving cell edge beam, the UE is not at serving cell edge.

Referring now to FIG. 5, a flowchart is depicted illustrating a fifth embodiment of the method for measurement before handover according to the disclosure, which is based on the first embodiment of the measurement before handover method and further comprises the following blocks before the block S12.

In S13, the base station may receive information of a second beam set from the base station of the neighbor cell.

The information of the second beam set may be transmitted from the base station of the neighbor cell to the base station of serving cell through interface between base stations, e.g., X2 interface. All beams in the second beam set may belong to the neighbor cell. The number of beams in the second beam set can be less than or equal to the total number of beams in the neighbor cell.

The execution of block S13 may be periodical with no restriction in the execution order of block S13 and block S11. Typically, serving ranges of beams in the second beam set may locate close to the serving cell. Alternatively, the execution of block S13 may be event triggered.

In S14, the base station may select information of the first beam set from information of the second beam set according to location information of the UE and/or information of beams in the second beam set.

The first beam set may be a subset of the second beam set. The number of beams in the first beam set is less than or equal to the number of beams in the second beam set.

The location information of the UE may comprise current location information (e.g., latitude and longitude coordinates) of the UE, and/or the serving beam information of the UE. Additionally, it may further comprise moving direction of the UE estimated according to the UE’s previous locations and/or serving beams. The base station may estimate the predicted location of UE when it is leaving the serving cell according to the location information of UE, and select one or more beams with serving ranges relatively close to the predicted location to form the first beam set. If certain beam (s) in the second beam set is unavailable, the base station shall not add it/them to the first beam set. The unavailable beam may comprise beam that is too far from the serving cell, beam transmitted from off TRP, etc..

Block S14 may be omitted and thus the first beam set may be equal to the second beam set.

In one embodiment, the second beam set may comprise one or multiple beam subsets, and the base station may select one of them as the first beam set.

Referring now to FIG. 6, a flowchart is depicted illustrating a sixth embodiment of the method for measurement before handover according to the disclosure, which is based on the fifth embodiment of the measurement before handover method and in which execution of block S13 is event triggered. The triggering event is that the UE meeting the condition of measurement. The present embodiment is a further extension of the first embodiment and fifth embodiment, so the common contents as those of the first embodiment and fifth embodiment will not be detailed again. The method according to the present embodiment may comprise the following blocks.

In S121, the base station may determine whether a User Equipment (UE) meets measurement triggering condition.

In S122, the base station may transmit a beam information request to the base station of the neighbor cell when the UE meets the measurement triggering condition.

The beam information request may comprise location information of the UE. The location information of the UE may comprise current location information (e.g., latitude and longitude coordinates) of the UE, and/or the serving beam information of the UE. Additionally, it may further comprise moving direction of the UE estimated according to the UE’s previous locations and/or serving beams. The base station may estimate the predicted location of UE when it is entering the neighbor cell according to the location information of UE.

Compared with the time cost of the whole handover procedure, adding the beam information request may lead to additional time delay, but reduce size of data processed by the base stations and the UE, while the latency will not being too much because of rapid turnaround of the X2 traffic.

In S123, the base station may receive information of the second beam set from the base station of the neighbor cell.

In S124, the base station may select information of a first beam set from information of the second beam set according to at least one of location information of the UE and information of beams in the second beam set.

In S125, the base station may transmit a measurement notification and information of the first beam set to the UE.

In one embodiment, the neighbor cell may comprise multiple TPRs. Each TRP transmits beams individually. Beams in the first beam set may belong to at least one TRP in the neighbor cell, and beams in the first beam set may comprise partial or all beams transmitted from the TRP mentioned above.

For example, referring to FIG. 7, dashed-line beams belong to the first beam set and TRP (s) within dashed coverage area transmits beams in the corresponding first beam set. In neighbor cell A, partial of beams transmitted from TRP A1 belong to the corresponding first beam set. In neighbor cell B, all beams transmitted from TRP B1 belong to the corresponding first beam set. In neighbor cell C, partial beams transmitted from TRP C1 and C2 belong to the corresponding first beam set. In neighbor cell D, all beams transmitted from TRP D1 and D2 belong to the corresponding first beam set.

Referring now to FIG. 8, a flowchart is depicted illustrating a seventh embodiment of the method for measurement before handover according to the disclosure. The method may be implemented on a UE. The UE can be stationary or mobile, including, but not limited to, cellular phones, personal digital assistants (PDA) , wireless modems, tablet computers, notebook computers, cordless phones, and so forth. The method according to the present embodiment can comprise the following blocks.

In S21, the UE may receive a measurement notification and information of a first beam set transmitted from a base station of a serving cell when the base station of the serving cell determining that the UE meets the measurement triggering condition.

All beams in the first beam set belong to a neighbor cell.

In S22, the UE may measure beams in the first beam set before handover.

The information of the first beam set may comprise time/frequency resources information of beams in the first beam set, therefore the UE may measure beams in the first beam set from the indicated time/frequency resources accordingly.

The measurement triggering condition may comprise the UE being high-mobility or the UE being at serving cell edge. The number of beams in the first beam set may be less than the total number of beams in the neighbor cell. Beams in the first beam set may belong to at least one TRP in the neighbor cell, and beams in the first beam set comprise partial or all beams transmitted from the TRP mentioned above. The number of beams in the first beam set may a positive correlation with carrier frequency of the neighbor cell. For details, see the relevant description of the previous embodiments of the method for handover before measurement.

Referring now to FIG. 9, a block diagram is depicted illustrating a first embodiment of a base station according to the disclosure. The base station may comprise a determination module 11 and a transmission module 12.

The determination module 11 may be configured to determine whether a User Equipment (UE) meets a measurement triggering condition.

The transmission module 12 may be configured to transmit a measurement notification and information of a first beam set to the UE when the UE meets the measurement triggering condition, so that the UE measures beams in the first beam set before handover, wherein all beams in the first beam set belong to a neighbor cell.

Referring now to FIG. 10, a block diagram of a second embodiment of a base station according to the disclosure is depicted, which is based on the first embodiment of the base station and further comprises a request module 13, a receiving module 14 and a selection module 15.

The request module 13 may be configured to transmit a beam information request to the base station of the neighbor cell.

The receiving module 14 may be configured to receive information of the second beam set from the base station of the neighbor cell.

The selection module 15 may be configured to select information of the first beam set from information of the second beam set according to at least one of location information of the UE and information of beams in the second beam set.

Specifically, the measurement triggering condition may comprise the UE being high mobility or the UE being at serving cell edge.

Specifically, the determination module 11 may be configured to determine whether the number of beam switching in a judging duration is greater than a predetermined threshold so as to determine whether the UE is high mobility.

Specifically, the determination module 11 may be configured to determine whether the UE is connected to a serving cell edge beam so as to determine whether the UE is at serving cell edge.

Specifically, the first beam set may be a subset of a second beam set, information of the second beam set may be transmitted from a base station of the neighbor cell and all beams in the second beam set may belong to the neighbor cell.

Specifically, the number of beams in the first beam set may have a positive correlation with carrier frequency of the neighbor cell.

Specifically, the number of beams in the first beam set may be less than the total number of beams in the neighbor cell.

Referring now to FIG. 11, a block diagram of a second embodiment of a base station is depicted. The base station may comprise a processor 110 and a transceiver 120 coupled to processor 110 via a bus.

The transceiver 120 may be configured to transmit and receive data, and serve as an interface through which the base station communicates with other communication equipment.

Processor 110 may control operations of the base station, and may also be referred to as a Central Processing Unit (CPU) . Processor 110 may be an integrated circuit chip with signal processing capabilities, such as a general purpose processor, Digital Signal Processor (DSP) , Application Specific Integrated Circuit (ASIC) , Field Programmable Gate Array (FPGA) , or any other programmable logic devices, discrete gates, transistor logic devices, or discrete hardware components. The general purpose processor may be a microprocessor or any conventional processor.

The base station may further comprise a memory (not shown) used to store the commands and data necessary for operations of the processor 110. The memory can also store the data received by the transceiver 120.

Processor 110 may be configured to: determine whether a User Equipment (UE) meets a measurement triggering condition； and transmit via the transceiver 120 a measurement notification and information of a first beam set to the UE when the UE meets the measurement triggering condition, so that the UE measures beams in the first beam set before handover, wherein all beams in the first beam set belong to a neighbor cell.

Specifically, the processor 110 may be configured to determine whether the UE is high mobility； when the UE is a high-mobility UE, determine that the UE meets the measurement triggering condition, when the UE is not high mobility, determine whether the UE is at serving cell edge； when the UE is at serving cell edge, determine that the UE meets the measurement triggering condition, when the UE is not at serving cell edge, determine that the UE does not meet the measurement triggering condition.

Specifically, the processor 110 may be configured to determine whether the number of beam switching in a judging duration is greater than a predetermined threshold so as to determine whether the UE is high mobility.

Specifically, the processor 110 may be configured to determine whether the UE is connected to a serving cell edge beam so as to determine whether the UE is at serving cell edge.

Specifically, the processor 110 may be further configured to receive via the transceiver 120 information of the second beam set from the base station of the neighbor cell before transmitting via the transceiver 120 the measurement notice and information of the first beam set to the UE.

Specifically, the processor 110 may be further configured to transmit via the transceiver 120 a beam information request to the base station of the neighbor cell after determining that the UE meets the measurement triggering condition, before receiving via the transceiver 120 information of the second beam set from the base station of the neighbor cell.

Specifically, the beam information request may comprise location information of the UE.

Specifically, the processor may be further configured to select information of the first beam set from information of the second beam set according to at least one of location information of the UE and information of beams in the second beam set before transmitting via the transceiver 120 the measurement notice and information of the first beam set to the UE.

Specifically, the second beam set may comprise one or multiple beam subsets, and the first beam set is one of the beam subsets.

Specifically, beams in the first beam set may belong to one or multiple TRP in the neighbor cell, and beams in the first beam set may comprise partial or all beams transmitted from the TRP.

For functions of various components or modules of the base station according to the present embodiment, one may refer to the relevant description of corresponding method embodiment, thus they will not be detailed again.

Referring now to FIG. 12, a first embodiment of a UE according to the disclosure is depicted. The UE may comprise a receiving module 21 and a measurement module 22.

The receiving module 21 may be configured to receive a measurement notification and information of a first beam set transmitted from a base station of a serving cell when the base station of the serving cell determining that the UE meets the measurement triggering condition, wherein all beams in the first beam set belong to a neighbor cell.

The measurement module 22 may be configured to measure beams in the first beam set before handover.

Referring now to FIG. 12, a block diagram of a third embodiment of a UE according to the disclosure is depicted. The UE may comprise a processor 210 and a communication circuit 220 coupled to the processor 210 via a bus.

The communication circuit 220 may be configured to transmit and receive data, and serve as an interface through which the UE communicates with other communication equipment.

Processor 210 may control operations of the UE, and can also be referred to as a CPU. Processor 210 may be an integrated circuit chip with signal processing capabilities. Processor 210 may also be a general purpose processor, DSP, ASIC, FPGA, or other programmable logic devices, discrete gates, transistor logic devices, discrete hardware components. The general purpose processor may be a microprocessor or any conventional processor.

The UE may further include a memory (not shown) used to store the commands and data necessary for operations of the processor 210. The memory can also store the data received by the communication circuit 220.

Processor 210 may be configured to: receive via the communication circuit 220a measurement notification and information of a first beam set transmitted from a base station of a serving cell when the base station of the serving cell determining that the UE meets the measurement triggering condition, wherein all beams in the first beam set belong to a neighbor cell； and measure beams in the first beam set via the communication circuit 220 before handover.

For functions of various components or modules of the UE according to the present embodiment, one may refer to the relevant description of corresponding method embodiment, thus they will not be detailed again.

It will be appreciated that the disclosed base stations, UEs, and methods may also be implemented in other forms. Rather, the base stations and UEs as described are merely illustrative, for example, the division of modules or units is based solely on logic functions, thus in actual implementations there may be other division methods, e.g., multiple units or components may be combined or integrated onto another system, or some features may be ignored or not executed. In addition, mutual couplings, direct couplings, or communication connections as displayed or discussed may be achieved through some interfaces, devices, or units, and may be achieved electrically, mechanically, or in other forms.

Separated units as described may or may not be physically separated. Components displayed as units may or may not be physical units, and may reside at one location or may be distributed to multiple networked units. Part or all of the units may be selectively adopted according to actual requirements to achieve objectives of the disclosure.

Additionally, various functional units discussed in the disclosure may be integrated into one processing unit, or may be presented as various physically separated units, and two or more units may be integrated into one. The integrated units may be implemented by hardware or as software functional units.

If the integrated units are implemented as software functional units and sold or used as standalone products, they may be stored in a computer readable storage medium. On the basis of such an understanding, the substantial technical solution or all or part of the technical solution of the disclosure may be embodied as software products. Computer software products can be stored in a storage medium and can include multiple instructions enabling a computing device (e.g., a personal computer, a server, a network device, etc. ) or a processor to execute all or part of the methods as described in the disclosure. The storage medium may include all kinds of media that can store program codes, such as a USB flash disk, mobile hard drive, Read-Only Memory (ROM) , Random Access Memory (RAM) , magnetic disk, or optical disk.

The above description merely depicts some exemplary embodiments of the disclosure, but is not meant to limit the scope of the disclosure. Any equivalent structure or flow transformations made to the disclosure, or any direct or indirect applications of the disclosure on other related fields, shall all be covered within the protection of the disclosure.

Claims

A method for measurement before handover, comprising:

determining, by a base station, whether a User Equipment (UE) meets a measurement triggering condition；

when the UE meets the measurement triggering condition, transmitting, by the base station, a measurement notification and information of a first beam set to the UE, so that the UE measures beams in the first beam set before handover, wherein all beams in the first beam set belong to a neighbor cell.
The method according to claim 1, wherein the measurement triggering condition comprises the UE being high mobility or the UE being at serving cell edge.
The method according to claim 2, wherein the block of the base station determining whether the UE meets the measurement triggering condition comprises:

determining, by the base station, whether the UE is high mobility；

when the UE is high mobility, determining, by the base station, that the UE meets the measurement triggering condition, when the UE is not high mobility, determining, by the base station, whether the UE is at serving cell edge；

when the UE is at serving cell edge, determining, by the base station, that the UE meets the measurement triggering condition, when the UE is not at serving cell edge, determining, by the base station, that the UE does not meet the measurement triggering condition.
The method according to claim 3, wherein the block of the base station determining whether the UE is high mobility comprises:

determining, by the base station, whether the number of beam switching in a judging duration is greater than a predetermined threshold.
The method according to claim 3, wherein the block of the base station determining whether the UE is at serving cell edge comprises:

determining, by the base station, whether the UE is connected to a serving cell edge beam.
The method according to claim 1, wherein the first beam set is a subset of a second beam set, information of the second beam set is transmitted from a base station of the neighbor cell and all beams in the second beam set belong to the neighbor cell.
The method according to claim 6, further comprising, before the base station transmitting the measurement notice and information of the first beam set to the UE:

receiving, by the base station, information of the second beam set from the base station of the neighbor cell.
The method according to claim 7, further comprising, after the base station determining that the UE meets the measurement triggering condition, and before receiving information of the second beam set from the base station of the neighbor cell:

transmitting, by the base station, a beam information request to the base station of the neighbor cell.
The method according to claim 8, wherein the beam information request comprises location information of the UE.
The method according to any one of claims 6-9, further comprising, before transmitting the measurement notice and information of the first beam set to the UE:

selecting, by the base station, information of the first beam set from information of the second beam set according to at least one of location information of the UE and information of beams in the second beam set.
The method according to any one of claims 6-9, wherein the second beam set comprises one or multiple beam subsets, and the first beam set is one of the beam subsets.
The method according to any one of claims 1-9, wherein the number of beams in the first beam set is less than the total number of beams in the neighbor cell.
The method according to any one of claims 1-9, wherein beams in the first beam set belong to at least one TRP in the neighbor cell, and beams in the first beam set comprise partial or all beams transmitted from the TRP.
The method according to any one of claims 1-9, wherein the number of beams in the first beam set has a positive correlation with carrier frequency of the neighbor cell.
A method for measurement before handover, comprising:

receiving, by a User Equipment (UE) , a measurement notification and information of a first beam set transmitted from a base station of a serving cell when the base station of the serving cell determining that the UE meets the measurement triggering condition, wherein all beams in the first beam set belong to a neighbor cell；

measuring, by the UE, beams in the first beam set before handover.
The method according to claim 15, wherein the measurement triggering condition comprises the UE being high mobility or the UE being at serving cell edge.
The method according to claim 15, wherein the number of beams in the first beam set is less than the total number of beams in the neighbor cell.
The method according to claim 15, wherein beams in the first beam set belong to at least one TRP in the neighbor cell, and beams in the first beam set comprise partial or all beams transmitted from the TRP.
The method according to any one of claims 15-18, wherein the number of beams in the first beam set has a positive correlation with carrier frequency of the neighbor cell.
A base station, comprising:

a determination module configured to determine whether a User Equipment (UE) meets a measurement triggering condition；

a transmission module configured to transmit a measurement notification and information of a first beam set to the UE when the UE meets the measurement triggering condition, so that the UE measures beams in the first beam set before handover, wherein all beams in the first beam set belong to a neighbor cell.
The base station according to claim 20, wherein the measurement triggering condition comprises the UE being high mobility or the UE being at serving cell edge.
The base station according to claim 20, wherein the determination module is configured to determine whether the number of beam switching in a judging duration is greater than a predetermined threshold so as to determine whether the UE is high mobility.
The base station according to claim 20, wherein the determination module is configured to determine whether the UE is connected to a serving cell edge beam so as to determine whether the UE is at serving cell edge.
The base station according to claim 20, wherein the first beam set is a subset of a second beam set, information of the second beam set is transmitted from a base station of the neighbor cell and all beams in the second beam set belong to the neighbor cell.
The base station according to claim 20, further comprising:

a request module configured to transmit a beam information request to the base station of the neighbor cell；

a receiving module configured to receive information of the second beam set from the base station of the neighbor cell.

a selection module configured to select information of the first beam set from information of the second beam set according to at least one of location information of the UE and information of beams in the second beam set.
The base station according to any one of claims 20-25，wherein the number of beams in the first beam set is less than the total number of beams in the neighbor cell.
A user equipment (UE) , comprising:

a receiving module configured to receive a measurement notification and information of a first beam set transmitted from a base station of a serving cell when the base station of the serving cell determining that the UE meets the measurement triggering condition, wherein all beams in the first beam set belong to a neighbor cell；

a measurement module configured to measure beams in the first beam set before handover.
The UE according to claim 27, wherein the measurement triggering condition comprises the UE being high mobility or the UE being at serving cell edge.
A base station, comprising a processor and a transceiver connected to the processor； the processor being configured to: determine whether a User Equipment (UE) meets a measurement triggering condition； and transmit via the transceiver a measurement notification and information of a first beam set to the UE when the UE meets the measurement triggering condition, so that the UE measures beams in the first beam set before handover, wherein all beams in the first beam set belong to a neighbor cell.
The base station according to claim 29, wherein the measurement triggering condition comprises the UE being high mobility or the UE being at serving cell edge.
The base station according to claim 30, wherein the processor is configured to determine whether the UE is high mobility； when the UE is high mobility UE, determine that the UE meets the measurement triggering condition, when the UE is not high mobility, determine whether the UE is at serving cell edge； when the UE is at serving cell edge, determine that the UE meets the measurement triggering condition, when the UE is not at serving cell edge, determine that the UE does not meet the measurement triggering condition.
The base station according to claim 31, wherein the processor is configured to determine whether the number of beam switching in a judging duration is greater than a predetermined threshold so as to determine whether the UE is high mobility.
The base station according to claim 31, wherein the processor is configured to determine whether the UE is connected to a serving cell edge beam so as to determine whether the UE is at serving cell edge.
The base station according to claim 29, wherein the first beam set is a subset of a second beam set, information of the second beam set is transmitted from a base station of the neighbor cell and all beams in the second beam set belong to the neighbor cell.
The base station according to claim 34, wherein the processor is further configured to receive via the transceiver information of the second beam set from the base station of the neighbor cell before transmitting via the transceiver the measurement notice and information of the first beam set to the UE.
The base station according to claim 35, wherein the processor is further configured to transmit via the transceiver a beam information request to the base station of the neighbor cell after determining that the UE meets the measurement triggering condition, before receiving via the transceiver information of the second beam set from the base station of the neighbor cell.
The base station according to claim 36, wherein the beam information request comprises location information of the UE.
The base station according to any one of claims 34-37, wherein the processor is further configured to select information of the first beam set from information of the second beam set according to at least one of location information of the UE and information of beams in the second beam set before transmitting via the transceiver the measurement notice and information of the first beam set to the UE.
The base station according to any one of claims 34-37, wherein the second beam set comprises one or multiple beam subsets, and the first beam set is one of the beam subsets.
The base station according to any one of claims 29-37, wherein the number of beams in the first beam set is less than the total number of beams in the neighbor cell.
The base station according to any one of claims 29-37, wherein beams in the first beam set belong to one or multiple TRP in the neighbor cell, and beams in the first beam set comprise partial or all beams transmitted from the TRP.
The base station according to any one of claims 29-37, wherein the number of beams in the first beam set has a positive correlation with carrier frequency of the neighbor cell.
A user equipment (UE) , comprising a processor and a communication circuit connected to the processor； the processor being configured to: receive via the communication circuit a measurement notification and information of a first beam set transmitted from a base station of a serving cell when the base station of the serving cell determining that the UE meets the measurement triggering condition, wherein all beams in the first beam set belong to a neighbor cell； and measure beams in the first beam set via the communication circuit before handover.
The UE according to claim 43, wherein the measurement triggering condition comprises the UE being high mobility or the UE being at serving cell edge.
The UE according to claim 43, wherein the number of beams in the first beam set is less than the total number of beams in the neighbor cell.
The UE according to claim 45, wherein beams in the first beam set belong to one or multiple TRP in the neighbor cell, and beams in the first beam set comprise partial or all beams transmitted from the TRP.
The UE according to any one of claims 43-46, wherein the number of beams in the first beam set has a positive correlation with carrier frequency of the neighbor cell.