WO2021168603A1

WO2021168603A1 - Event triggered measurement for channel state information

Info

Publication number: WO2021168603A1
Application number: PCT/CN2020/076384
Authority: WO
Inventors: Lars Dalsgaard; Lei Du
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2020-02-24
Filing date: 2020-02-24
Publication date: 2021-09-02
Also published as: CN115152318A; CN115152318B

Abstract

Example embodiments of the present disclosure relate to devices, methods, apparatuses and computer readable storage media of an event triggered measurement for CSI. The method comprising receiving, from a second device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device; determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell; and in accordance with a determination that the at least one event is triggered, perform one of the following operations: initiating a second measurement on a second reference signal from at least one second cell associated with the first device, and ceasing the second measurement. In this way, the UE can measure CSI-RS for mobility only when it is needed, which may minimize the UE measurement efforts and also save power consumption of the UE. Meanwhile, the network overhead may also be reduced.

Description

EVENT TRIGGERED MEASUREMENT FOR CHANNEL STATE INFORMATION

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to a device, method, apparatus and computer readable medium of an event triggered measurement for Channel State Information (CSI) .

BACKGROUND

In New Radio (NR) Release 15, the 3rd Generation Partnership Project (3GPP) has defined a frame work of a CSI-Reference Signal (CSI-RS) for the beam management and the mobility management. The CSI-RS based mobility role plays an important factor in mobility and network deployment and optimization. Compared to Synchronization Signal Block (SSB) based Radio Resource (RRM) measurement, CSI-RS based RRM measurement is more accurate and flexible in terms of resource usage, mobility enhancement and handover reliability.

The network may configure the user equipment (UE) to perform RRM measurement based on SSB and/or CSI-RS. Different from SSB-based measurement where SSBs are continuously and periodically broadcasted from the network, CSI-RS is configured via a signalling per-UE, e.g. RRCReconfigure messages.

SUMMARY

In general, example embodiments of the present disclosure provide a solution of an event triggered measurement for CSI-RS.

In a first aspect, there is provided a first device. The first device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device at least to receive, from a second device, a message comprising at least one event related to a service quality of at least one first cell associated with the first device; determine whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell; and in accordance with a determination that the at least one event is triggered, perform one of the following operations: initiating a second measurement on a second reference signal from a second cell associated with the first device, and ceasing the second measurement.

In a second aspect, there is provided a second device. The second device comprises at least one processor; and at least one memory including computer program codes; the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device at least to transmit, to a first device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device, to cause the first device to perform of the following operations: determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell and initiating a second measurement on a second reference signal from at least one second cell, and determining whether the at least one event is triggered based on the first measurement and ceasing the second measurement.

In a third aspect, there is provided a method. The method comprises receiving, from a second device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device; determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell; and in accordance with a determination that the at least one event is triggered, perform one of the following operations: initiating a second measurement on a second reference signal from at least one second cell associated with the first device, and ceasing the second measurement.

In a fourth aspect, there is provided a method. The method comprises transmitting, to a first device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device, to cause the first device to perform of the following operations: determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell and initiating a second measurement on a second reference signal from at least one second cell, and determining whether the at least one event is triggered based on the first measurement and ceasing the second measurement.

In a fifth aspect, there is provided an apparatus comprising means for receiving, from a second device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device; means for determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell; and means for in accordance with a determination that the at least one event is triggered, perform one of the following operations: initiating a second measurement on a second reference signal from at least one second cell associated with the first device, and ceasing the second measurement.

In an sixth aspect, there is provided an apparatus comprising means for transmitting, to a first device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device, to cause the first device to perform of the following operations: determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell and initiating a second measurement on a second reference signal from at least one second cell, and determining whether the at least one event is triggered based on the first measurement and ceasing the second measurement.

In a seventh aspect, there is provided a computer readable medium comprising a computer program for causing an apparatus to perform at least the method according to the third aspect.

In an eighth aspect, there is provided a computer readable medium comprising a computer program for causing an apparatus to perform at least the method according to the fourth aspect.

It is to be understood that the summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

FIG. 1 shows an example communication network in which embodiments of the present disclosure may be implemented;

FIG. 2 shows a signaling chart illustrating an event triggered measurement for CSI according to some example embodiments of the present disclosure;

FIG. 3 shows a flowchart of a method implemented at a first device in accordance with some example embodiments of the present disclosure;

FIG. 4 shows a flowchart of a method implemented at a second device in accordance with some example embodiments of the present disclosure;

FIG. 5 illustrates a simplified block diagram of an apparatus that is suitable for implementing some other embodiments of the present disclosure; and

FIG. 6 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. The disclosure described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an example embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish functionalities of various elements. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as fifth generation (5G) systems, Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the future fifth generation (5G) new radio (NR) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , a NR Next Generation NodeB (gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. An RAN split architecture comprises a gNB-CU (Centralized unit, hosting RRC, SDAP and PDCP) controlling a plurality of gNB-DUs (Distributed unit, hosting RLC, MAC and PHY) . A relay node may correspond to DU part of the IAB node.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. The terminal device may also correspond to Mobile Termination (MT) part of the integrated access and backhaul (IAB) node (a.k.a. a relay node) . In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

Although functionalities described herein can be performed, in various example embodiments, in a fixed and/or a wireless network node, in other example embodiments, functionalities may be implemented in a user equipment apparatus (such as a cell phone or tablet computer or laptop computer or desktop computer or mobile IoT device or fixed IoT device) . This user equipment apparatus can, for example, be furnished with corresponding capabilities as described in connection with the fixed and/or the wireless network node (s) , as appropriate. The user equipment apparatus may be the user equipment and/or or a control device, such as a chipset or processor, configured to control the user equipment when installed therein. Examples of such functionalities include the bootstrapping server function and/or the home subscriber server, which may be implemented in the user equipment apparatus by providing the user equipment apparatus with software configured to cause the user equipment apparatus to perform from the point of view of these functions/nodes.

FIG. 1 shows an example communication network 100 in which embodiments of the present disclosure can be implemented. As shown in FIG. 1, the communication network 100 comprises a terminal device 110 (hereafter also referred to as a first device 110 or an UE 110) and network devices 120-1 and 120-2 (hereafter also referred to as a second device 120-1 and a third device 120-2, respectively) . The terminal device 110 may communicate with the network devices 120-1 and 120-2. The network devices 120-1 and 120-2 may communicate with each other. The serving area of the network device 120-1 is called as a cell 102, and the serving area of the network device 120-2 is called as a cell 104. It is to be understood that the number of network devices and terminal devices shown in FIG. 1 is given for the purpose of illustration without suggesting any limitations. The communication network 100 may include any suitable number of network devices and terminal devices.

Depending on the communication technologies, the network 100 may be a Code Division Multiple Access (CDMA) network, a Time Division Multiple Address (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency-Division Multiple Access (OFDMA) network, a Single Carrier-Frequency Division Multiple Access (SC-FDMA) network or any others. Communications discussed in the network 100 may conform to any suitable standards including, but not limited to, New Radio Access (NR) , Long Term Evolution (LTE) , LTE-Evolution, LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , Code Division Multiple Access (CDMA) , cdma2000, and Global System for Mobile Communications (GSM) and the like. Furthermore, the communications may be performed according to any generation communication protocols either currently known or to be developed in the future. Examples of the communication protocols include, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) communication protocols. The techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, certain aspects of the techniques are described below for LTE, and LTE terminology is used in much of the description below.

As mentioned above, in NR Release 15, the 3GPP has defined a frame work of a CSI-RS for the beam management and the mobility management. The CSI-RS based mobility plays an important role and can be considered as an important factor in mobility and network deployment and optimization. Compared to SSB-based RRM measurement, CSI-RS based RRM measurement is more accurately and flexible in terms of resource usage, mobility enhancement and handover reliability.

The network may configure the UE to perform RRM measurement based on SSB and/or CSI-RS. Different from SSB-based measurement where SSBs are continuously and periodically broadcasted from the network, CSI-RS is configured via a signalling per-UE, e.g. RRCReconfigure messages.

The CSI-RS-based measurement for mobility is configured via the signaling “CSI-RS-ResourceConfigMobility” . For each neighbor cell to be measured for a Measurement Object (MO) to be measured, the UE may be configured to measure a list of CSI-RS resources with specific time/frequency location.

As shown in FIG. 1, the UE 110 in cell 102 is configured to measure the CSI-RS in neighbour cell 104. The CSI-RS resources used for the neighbour cell measurements 104 are informed to the UE 110 by cell 102 (the network device 120-1) via Xn messages between the network device 120-1 and the network device 120-2, so that the cell 104 (the network device 120-2) can configure, via the serving cell 102, the CSI-RS resources to be measured, to the UE 110 accordingly. That is, the CSI-RS is transmitted from the cell 104, while the measurement configuration is generated from the cell 102.

For this reason, the network device 120-2 has no information whether and when the UE 110 is actually able to or required to measure CSI-RS for the cell 104. The network device 120-2 would have to continuously keep sending CSI-RSs so that they can be measured by the UE 110 once needed. Although the CSI-RS measurements may be intended to provide finer information about resource usage or for beam refinement purposes, transmitting the CSI-RS resources consumes radio resources and thus brings big overhead to the network.

On the other hand, the SSB is mandatorily transmitted and configured at least on the initial Downlink Band Width Part (DL BWP) and SSB-based measurements have been implemented as the basic RRM measurement for mobility. When the CSI-RS based measurements are introduced, they can be configured together with SSB-based measurements to provide further finer measurement granularity to assist e.g. beam selection during handover, i.e. setting both ssb-configMobility and csi-rs-ResrouceConfigMobility in the measurement configuration.

Referring back to FIG. 1, for example, the network device 120-1 may configure the UE 110 in RRC_CONNECTED via Measconfig to perform measurements and potentially report the measurement results to the network in accordance with the measurement configuration. The measurement configuration may include the parameters such as Measurement Objects (MOs) , Reporting configurations, Measurement identities, Quantity configurations and Measurement gaps, wherein SSB-based and CSI-RS based measurements are configured separately. However, it is not defined how to configure the two measurements to ensure proper UE behaviour and to provide meaningful results to the network.

Therefore, the present disclosure proposes a solution to initiate or cease the CSI-RS measurements by an UE based on a SSB-based measurement, which may guide the UE to perform the CSI-RS measurement when a SSB-based event is triggered. Furthermore, the network may inform the cell to be measured when the UE performs the CSI-RS measurements, so that the cell to be measured may not have to continuously keep sending CSI-RSs all the time. In this way, the UE can measure CSI-RS for mobility only when it is needed, which may minimize the UE measurement efforts and also save power consumption of the UE. Meanwhile, the network overhead may also be reduced.

Principle and implementations of the present disclosure will be described in detail below with reference to FIGs. 2 to 4. FIG. 2 shows a signaling chart illustrating an event triggered measurement for CSI-RS according to some example embodiments of the present disclosure. For the purpose of discussion, the process 200 will be described with reference to FIG. 1. The process 200 may involve the first device 110, the second device 120-1 and the third device 120-2 as illustrated in FIG. 1. It would be appreciated that although the process 200 has been described in the communication network 100 of FIG. 1, this process may be likewise applied to other communication scenarios.

As shown in FIG. 2, the network device 120-1 transmits 205 a message to the terminal device 110. The message may comprise at least one event associated with e.g. the service quality of at least a cell associated with the terminal device 110. Herein the term “cell” may be referred to as a cell serving the terminal device 110, i.e. the cell 102 shown in FIG. 1. Herein the term “cell” may be referred to as any neighboring cell of the serving cell of the terminal device 110, e.g. the cell 104 shown in FIG. 1.

Herein the term “event” may be referred to a SSB-based event. For example, the event may be represented as “serving cell becomes better than threshold” or “neighbour cell becomes a threshold better than the serving cell” . Each event may be identified with an index in the reporting configuration, i.e. reportconfigID. It is to be understood that the message may also comprise more events. The indices of the events and its corresponding description may be known on both sides of the network devices and terminal device via the reporting configuration transmitted from the network device to the terminal device.

Herein the service quality may be referred to as a level/a value typically characterizing the quality of a first reference signal, such as Synchronization Signal-Reference Signal Receiving Power, SS-RSRP, Synchronization Signal-Reference Signal Receiving Quality, SS-RSRQ, Synchronization Signal-Signal-to-Interference and Noise Ratio, SS-SINR, Synchronization Signal-Received Signal Strength Indicator, SS-RSSI or similar measured measurement quantity.

Furthermore, the message may also indicate that a CSI-RS based RRM measurement is initiated or ceased implicitly or explicitly based on the event being triggered. For example, it can be preconfigured that the terminal device 110 may initiate or cease a CSI-RS based RRM measurement when a certain event is triggered, which may not require any change of the signaling. As another option, the message may comprise an indication indicating that the CSI-RS based RRM measurement is to be initiated at the terminal device 110 when a certain event is triggered and/or the CSI-RS based RRM measurement is to be ceased at the terminal device 110 when a certain event is triggered. The message may also comprise measurement configuration for both SSB-based measurement and CSI-RS L3 based measurements in one MO.

Referring back to FIG. 2, the terminal device 110 may determine 210 whether the event indicated in the message is triggered. For example, the terminal device 110 may performed a SSB-based RRM measurement of a reference signal received from the network device 120-1 to determine whether the event is triggered. Alternatively, depending on a measurement object associated with the event, the terminal device 110 may also performed a SSB-based RRM measurement of a reference signal received from the network device 120-1 and/or 120-2 to determine whether the event is triggered. If the terminal device 110, based on the result of the SSB-based RRM measurement, determines that the condition indicated by the event is met, the terminal device 110 may determine that the event is triggered.

If the event is triggered, the terminal device 110 may initiate a CSI-RS-based RRM measurement. That is, the terminal device 110 may perform a CSI-RS based measurement on a reference signal from the serving cell and/or other cell. Alternatively, the terminal device 110 may cease a CSI-RS-based RRM measurement if the event is triggered. If the terminal device 110 perform the SSB based RRM measurement on the reference signal from the cell 102, the terminal device 110 may initiate/cease the CSI-RS-based RRM measurement on the reference signal from the serving cell 102 or one or more neighbor cell 104. If the terminal device 110 perform the SSB based RRM measurement on the reference signal from the cell 104, the terminal device 110 may initiate/cease the CSI-RS-based RRM measurement on the reference signal from the cell 102 and/or cell 104.

In a case that the message indicates that a CSI-RS based RRM measurement is to be initiated/ceased implicitly, i.e. the additional indication for initiating or ceasing the CSI-RS based RRM measurement is not included in the message, the terminal device 110 may initiate or cease a CSI-RS-based RRM measurement based on the pre-configured information, such as what kind of events may initiate or cease a CSI-RS-based RRM measurement. Thus, the pre-configured information may indicate, for example, the event A2 “serving cell becomes worse than threshold” may initiate a CSI-RS-based RRM measurement, or the event A1 “serving cell becomes better than threshold” may cease a CSI-RS-based RRM measurement. In this case, the terminal device 110 may determine the operation for the CSI-RS-based RRM measurement based on the preconfigured information. That is, a relationship between the event and an operation to be performed may be known on both sides of the network devices and terminal device.

In a case that the message indicates that a CSI-RS based RRM measurement is to be initiated/ceased explicitly, the terminal device 110 may obtain, from the message, the indication indicating which operation will be performed if this event is triggered or when the a CSI-RS based RRM measurement should be initiated/ceased. One example of the “associatedSSB” IE including the indication may be shown as below.

Table 1: example of the “associatedSSB” IE

In this IE, the field “associatedSSBEvents_START” may indicate the event type directly i.e. using reportconfigID or could be a bitmask indicating which one (s) of the events which has been configured for the associated SSB-based measurement shall be used to trigger CSI-RS based RRM measurements. Similarly, the field “associatedSSBEvents_STOP” can be configured to indicate the events which would stop the CSI-RS based measurement.

In a case that the SSB based RRM measurement is performed on the reference signal from the cell 102, upon receiving the measurement configuration, the terminal device 110 may start or continues performing SSB-based measurements and pends the CSI-RS based RRM measurements if “associatedSSBEvents_Start” is present. When the event corresponding to associatedSSBEvents_Start is triggered, the terminal device 110 may start measuring a reference signal from cell 102 of the network device 120-1 or cell 104 of the network device 120-2 or both.

In a case that the SSB based RRM measurement is performed on the reference signal from the cell 104, when the event corresponding to associatedSSBEvents_Start is triggered, the terminal device 110 may start measuring a reference signal from cell 102 of the network device 120-1 or cell 104 of the network device 120-2 or both.

Similarly, if associatedSSBEvents_Stop is present, the terminal device 110 may stop CSI-RS based measurement if the event corresponding to associatedSSBEvents_Stop is triggered.

It should be understood that the exampled in Table 1 are shown only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Any other suitable form of the message may also be considered as a part of the present disclosure. For example, this indication may also be included in other IEs e.g. reportConfigNR when reporting events are defined for SSB-based measurements.

Therefore, if the event is triggered, the terminal device 110 may initiate/cease the CSI-RS based RRM measurement based on the explicit or implicit indication in the message.

If the terminal device 110 determines that the CSI-RS based RRM measurement is to be initiated. As an option, the terminal device 110 may transmit 215 a measurement report of the result of the SSB-based RRM measurement to the network device 120-1. If the network device 120-1 receives the measurement report, the network device 120-1 may determine that the CSI-RS based RRM measurement is initiated at the terminal device 110. In some example embodiments, the network device 120-1 may inform 220 the network device 120-2 that the CSI-RS based RRM measurement is initiated, so that the network device 120-2 may transmit 225 the reference signals enabling the CSI-RS based RRM measurement on the neighbor cell by the terminal device 110. Additionally, the network device 120-1 may initiate 227 a transmission of the reference signal for enabling the CSI-RS based measurements on the serving cell by terminal device 110. The terminal device 110 may perform 230 the CSI-RS based RRM measurement on the reference signals received from at least one of the network device 120-2 and the network device 102-1.

In this case, the terminal device 110 may perform the CSI-RS based RRM measurement after the measurement report for the SSB-based RRM measurement is transmitted to the network device 120-1. Thus, the network device 120-1 may be aware of the start of the CSI-RS based RRM measurement at the terminal device 110 and control the transmission of the reference signal provided from at least one of the network device 120-2 and the network device 102-1.

In some example embodiments, the terminal device 110 may also start to perform the CSI-RS based RRM measurement after a certain period. The length of the period may be determined by considering the transmission time of the measurement report and the reaction time of at least one of the network device 120-1 or the network device 120-2 to send a reference signal.

As another option, if the terminal device 110 determines that the CSI-RS based RRM measurement is to be initiated, the terminal device 110 may perform 230 the CSI-RS based RRM measurement on the reference signal received from at least one of the network device 120-1 and the network device 120-2, without transmitting the measurement report to the network device 120-1.

After the measurements on the reference signal of at least one of the network device 120-2 and the network device 102-1 is completed, the terminal device 110 may transmit 235 the measurement report of the CSI-RS based RRM measurement to the network device 120-1.

Similar procedure may be performed for the case that the terminal device 110 determines that the CSI-RS based RRM measurement is to be ceased.

If the terminal device 110 determines that the CSI-RS based RRM measurement is to be ceased, as an option, the terminal device 110 may transmit 240 a measurement report of the result of a SSB-based RRM measurement to the network device 120-1. Alternatively, the terminal device 110 may transmit 240 a measurement report of the result of a CSI-RS-based RRM measurement, or the results of both a SSB-based RRM measurement and a CSI-RS based RRM measurement. If the network device 120-1 receives the measurement report, the network device 120-1 may determine that the CSI-RS based RRM measurement is ceased at the terminal device 110. In some example embodiments, the network device 120-1 may inform 245 the network device 120-2 that the CSI-RS based RRM measurement is ceased, so that the network device 120-2, possibly in addition to device 120-1, may stop transmitting a reference signal for the CSI-RS based RRM measurement to the terminal device 110. Additionally, the network device 120-1 may stop transmitting the reference signals to the terminal device 110. The terminal device 110 may cease 250 the CSI-RS based RRM measurement on the reference signal received from at least one of the network device 120-2 and the network device 102-1.

In this case, the terminal device 110 may cease the CSI-RS based RRM measurement after the measurement report for the SSB-based RRM measurement and/or the CSI-RS-based RRM measurement is transmitted to the network device 120-1. Thus, the network device 120-1, and potentially device 120-2, may be aware of the stop of the CSI-RS based RRM measurement at the terminal device 110.

As another option, if the terminal device 110 determines that the CSI-RS based RRM measurement is to be ceased, the terminal device 110 may cease 250 the CSI-RS based RRM measurement on the reference signal received from at least one of the network device 120-2 and the network device 102-1 without transmitting the measurement report to the network device 120-1.

In this way, for initiating the CSI-RS based measurement, the terminal device measures CSI-RS for mobility only when some certain SSB-based events are triggered and for ceasing the CSI-RS based measurement, the terminal device measures CSI-RS for mobility only when some certain SSB-based events or CSI-RS based event are triggered. Therefore, the cell to be measured for the CSI-RS based measurement is a qualified candidate target cell, and therefore the measurement efforts of the terminal device can be minimized and also the power consumption of the terminal device can be saved. Furthermore, it is benefit that the network device is not mandated to transmit the CSI-RS all the time but may start and stop transmission of the CSI-RS based on measurement reports from the terminal device.

FIG. 3 shows a flowchart of an example method 300 for service management in a communication system. According to some example embodiments of the present disclosure. The method 300 can be implemented at the first device 110 as shown in FIG. 1. For the purpose of discussion, the method 300 will be described with reference to FIG. 1.

As shown in FIG. 3, at 310, the first device 110 receives, from a second device 120-1, a message comprising at least one event related to a service quality of at least one first cell associated with the first device 110.

In some example embodiments, the service quality comprises a level of at least one of the following: Synchronization Signal-Reference Signal Receiving Power, SS-RSRP, Synchronization Signal-Reference Signal Receiving Quality, SS-RSRQ, Synchronization Signal-Signal-to-Interference and Noise Ratio, SS-SINR, Synchronization Signal-Received Signal Strength Indicator, SS-RSSI or a similar measured measurement metric.

In some example embodiments, the at least one first cell comprises at least one of the following: a serving cell of the first device, and a neighboring cell of the serving cell.

In some example embodiments, the at least one second cell comprises at least one of the following: a serving cell of the first device, and a neighboring cell of the serving cell.

In some example embodiments, the message further comprises one of the following an indication indicating that the second measurement is to be initiated at the first device based on the trigger of the at least one event, or an indication indicating that the second measurement is to be stopped at the first device based on the trigger of the at least one event.

At 320, the first device 110 determines whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell.

In some example embodiments, the first device 110 may obtain, from the first message, a set of configuration parameters associated with the at least one event and perform the first measurement based on the set of configuration parameters. If the first device 110 determines that a result of the first measurement meets a condition indicated by the at least one event, the first device 110 may determine that the at least one event is triggered.

At 330, if the first device 110 determines that the at least one event is triggered, the first device 110 performs one of the following operations: initiating a second measurement on a second reference signal from at least one second cell associated with the first device, and ceasing the second measurement.

In some example embodiments, the first device 110 may obtain, from the message, configuration information for reporting a result of at least one of the first measurement and the second measurement; and determine the at least one event from the configuration information by at least one of the following: an index of the configuration information, and a bitmask associated with the at least one event indicated in the configuration information.

In some example embodiments, if the first device 110 determines that the at least one event is triggered, the first device 110 may transmit a result of at least the first measurement to the second device.

In some example embodiments, if the first device 110 determines that the message indicates that the second measurement is to be initiated at the first device based on the trigger of the at least one event, the first device 110 may perform the second measurement after the transmission of the result of the first measurement.

In some example embodiments, if the first device 110 determines that the message indicates that the second measurement is to be ceased at the first device based on the trigger of the at least one event, the first device 110 may cease the second measurement after the transmission of the result of at least the first measurement.

In some example embodiments, if the first device 110 determines that the message indicates that the second measurement is to be initiated at the first device based on the trigger of the at least one event, the first device 110 may perform the second measurement without transmitting a result of the first measurement to the second device.

In some example embodiments, if the first device 110 determines that the message indicates that the second measurement is to be ceased at the first device based on the trigger of the at least one event, the first device 110 may cease the second measurement without transmitting a result of at least the first measurement to the second device.

In some example embodiments, the first device comprises a terminal device and the second device comprises a network device.

FIG. 4 shows a flowchart of an example method 400 for service management in a communication system according to some example embodiments of the present disclosure. The method 400 can be implemented at the second device 120-1 as shown in FIG. 1. For the purpose of discussion, the method 400 will be described with reference to FIG. 1.

As shown in FIG. 4, at 410, the second device 120-1 transmits, to a first device 110, a message at least one event related to a service quality of at least one first cell associated with the first device 110, to cause the first device to perform of the following operations: determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell and initiating a second measurement on a second reference signal from at least one second cell, and determining whether the at least one event is triggered based on the first measurement and ceasing the second measurement.

In some example embodiments, the second device 120-1 may transmit the second reference signal to the first device, if the second device receives, from the first device, a further indication for initiating or ceasing a transmission of the second reference signal from the second device to the first device.

In some example embodiments, the second device 120-1 may receive a result of a first measurement on the first reference signal from the first device. If the second device 120-1 determines that the at least one event is triggered based on the result, the second device 120-1 may generate, based on the message, a further indication for initiating or ceasing a transmission of the second reference signal from the at least one second cell to the first device and transmit the further indication to the at least one second cell.

In some example embodiments, the first device comprises a terminal device, and the second device comprises a network device.

In some example embodiments, an apparatus capable of performing the method 300 (for example, implemented at the terminal device 110) may comprise means for performing the respective steps of the method 300. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for receiving, from a second device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device; means for determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell; and means for in accordance with a determination that the at least one event is triggered, perform one of the following operations: initiating a second measurement on a second reference signal from at least one second cell associated with the first device, and ceasing the second measurement.

In some example embodiments, an apparatus capable of performing the method 400 (for example, implemented at the network device 120-1) may comprise means for performing the respective steps of the method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some example embodiments, the apparatus comprises means for transmitting, to a first device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device; and means for transmitting a first reference signal to the first device, to cause the first device to perform one of the following operations: determining whether the at least one event is triggered based on a first measurement on the first reference signal and initiating a second measurement on a second reference signal from at least one second cell associated with the first device based on the trigger of the at least one event, determining whether the at least one event is triggered based on a first measurement on the first reference signal and ceasing a second measurement on a second reference signal from at least one second cell associated with the first device based on the trigger of the at least one event, initiating a second measurement on the first reference signal, and ceasing a second measurement on the first reference signal.

FIG. 5 is a simplified block diagram of a device 500 that is suitable for implementing embodiments of the present disclosure. The device 500 may be provided to implement the communication device, for example the NRF 110 and the NF 120-1 as shown in FIG. 1. As shown, the device 500 includes one or more processors 510, one or more memories 540 coupled to the processor 510, and one or more transmitters and/or receivers (TX/RX) 540 coupled to the processor 510.

The TX/RX 540 is for bidirectional communications. The TX/RX 540 has at least one antenna to facilitate communication. The communication interface may represent any interface that is necessary for communication with other network elements.

The processor 510 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 500 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 520 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 524, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 522 and other volatile memories that will not last in the power-down duration.

A computer program 530 includes computer executable instructions that are executed by the associated processor 510. The program 530 may be stored in the ROM 520. The processor 510 may perform any suitable actions and processing by loading the program 530 into the RAM 520.

The embodiments of the present disclosure may be implemented by means of the program 530 so that the device 500 may perform any process of the disclosure as discussed with reference to FIGs. 2-4. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some embodiments, the program 530 may be tangibly contained in a computer readable medium which may be included in the device 500 (such as in the memory 520) or other storage devices that are accessible by the device 500. The device 500 may load the program 530 from the computer readable medium to the RAM 522 for execution. The computer readable medium may include any types of tangible non-volatile storage, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. FIG. 7 shows an example of the computer readable medium 700 in form of CD or DVD. The computer readable medium has the program 530 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. While various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, device, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the

methods

300 and 400 as described above with reference to FIGs. 3-4. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing device, such that the program codes, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program codes or related data may be carried by any suitable carrier to enable the device, device or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, while operations are depicted 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. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

A first device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device at least to:

receive, from a second device, a message comprising at least one event related to a service quality of at least one first cell associated with the first device;

determine whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell; and

in accordance with a determination that the at least one event is triggered, perform one of the following operations: initiating a second measurement on a second reference signal from at least one second cell associated with the first device, and ceasing the second measurement.
The device of Claim 1, wherein the service quality comprises a level of at least one of the following:

Synchronization Signal-Reference Signal Receiving Power, SS-RSRP,

Synchronization Signal-Reference Signal Receiving Quality, SS-RSRQ,

Synchronization Signal-Signal-to-Interference and Noise Ratio, SS-SINR, and

Synchronization Signal-Received Signal Strength Indicator, SS-RSSI.
The device of Claim 1, wherein the at least one first cell comprises at least one of the following:

a serving cell of the first device, and

a neighboring cell of the serving cell.
The device of Claim 1, wherein the at least one second cell comprises at least one of the following:

a serving cell of the first device, and

a neighboring cell of the serving cell.
The device of Claim 1, wherein the message further comprises one of the following:

an indication indicating that the second measurement is to be initiated at the first device based on the trigger of the at least one event, or

an indication indicating that the second measurement is to be stopped at the first device based on the trigger of the at least one event.
The device of Claim 1, wherein the first device is caused to determine whether the at least one event is triggered by:

obtaining, from the message, a set of configuration parameters associated with the at least one event;

performing the first measurement based on the set of configuration parameters; and

in accordance with a determination that a result of the first measurement meets a condition indicated by the at least one event, determining that the at least one event is triggered.
The device of Claim 1, wherein the first device is further caused to:

obtain, from the message, configuration information for reporting a result of at least one of the first measurement and the second measurement; and

determine the at least one event from the configuration information by at least one of the following:

an index of the configuration information, and

a bitmask associated with the at least one event indicated in the configuration information.
The device of Claim 1, wherein the first device is further caused to:

in accordance with a determination that the at least one event is triggered, transmit a result of at least the first measurement to the second device.
The device of Claim 8, wherein the first device is caused to perform one of the operations by:

in accordance with a determination that the message indicates that the second measurement is to be initiated at the first device based on the trigger of the at least one event, initiating the second measurement after the transmission of the result of the first measurement.
The device of Claim 8, wherein the first device is caused to perform one of the operations by:

in accordance with a determination that the message indicates that the second measurement is to be ceased at the first device based on the trigger of the at least one event, ceasing the second measurement after the transmission of the result of at least the first measurement.
The device of Claim 1, wherein the first device is caused to perform one of the operations by:

in accordance with a determination that the message indicates that the second measurement is to be initiated at the first device based on the trigger of the at least one event, performing the second measurement without transmitting a result of the first measurement to the second device.
The device of Claim 1, wherein the first device is caused to perform one of the operations by:

in accordance with a determination that the message indicates that the second measurement is to be ceased at the first device based on the trigger of the at least one event, ceasing the second measurement without transmitting a result of at least the first measurement to the second device.
The device of Claim 1, wherein the first device comprises a terminal device, and the second device comprises a network device.
A second device comprising:

at least one processor; and

at least one memory including computer program codes;

the at least one memory and the computer program codes are configured to, with the at least one processor, cause the second device at least to:

transmit, to a first device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device, to cause the first device to perform one of the following operations:

determining whether the at least one event is triggered based on a first measurement on the at least one first reference signal from the at least one first cell and initiating a second measurement on a second reference signal from at least one second cell, and

determining whether the at least one event is triggered based on at least the first measurement and ceasing the second measurement.
The device of Claim 14, wherein the service quality comprises a level of at least one of the following:

Synchronization Signal-Reference Signal Receiving Power, SS-RSRP,

Synchronization Signal-Reference Signal Receiving Quality, SS-RSRQ,

Synchronization Signal-Signal-to-Interference and Noise Ratio, SS-SINR, and

Synchronization Signal-Received Signal Strength Indicator, SS-RSSI.
The device of Claim 14, wherein the at least one first cell comprises at least one of the following:

a serving cell of the first device, and

a neighboring cell of the serving cell.
The device of Claim 14, wherein the at least one second cell comprises at least one of the following:

a serving cell of the first device, and

a neighboring cell of the serving cell.
The device of Claim 14, wherein the message further comprises an indication indicating that the second measurement is to be initiated at the first device based on the trigger of the at least one event or the second measurement is to be ceased at the first device based on the trigger of the at least one event.
The device of Claim 14, wherein the second device is caused to transmit the first reference signal by:

in response to receiving, from the first device, a further indication for initiating or ceasing a transmission of the first reference signal from the second device to the first device, transmit the first reference signal to the first device.
The device of Claim 14, wherein the second device is further caused to:

receive a result of a first measurement on the first reference signal from the first device;

in accordance with a determination that the at least one event is triggered based on the result, generate, based on the message, a further indication for initiating or ceasing a transmission of the second reference signal from the at least one second cell to the first device; and

transmit the further indication to the at least one second cell.
The device of Claim 14, wherein the first device comprises a terminal device, and the second device comprises a network device.
A method comprising:

receiving, from a second device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device;

determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell; and

in accordance with a determination that the at least one event is triggered, perform one of the following operations: initiating a second measurement on a second reference signal from at least one second cell associated with the first device, and ceasing the second measurement.
The method of Claim 22, wherein the service quality comprises a level of at least one of the following:

Synchronization Signal-Reference Signal Receiving Power, SS-RSRP,

Synchronization Signal-Reference Signal Receiving Quality, SS-RSRQ,

Synchronization Signal-Signal-to-Interference and Noise Ratio, SS-SINR, and

Synchronization Signal-Received Signal Strength Indicator, SS-RSSI.
The method of Claim 22, wherein the at least one first cell comprises at least one of the following:

a serving cell of the first device, and

a neighboring cell of the serving cell.
The method of Claim 22, wherein the at least one second cell comprises at least one of the following:

a serving cell of the first device, and

a neighboring cell of the serving cell.
The method of Claim 22, wherein the message further comprises one of the following:

an indication indicating that the second measurement is to be initiated at the first device based on the trigger of the at least one event, or

an indication indicating that the second measurement is to be stopped at the first device based on the trigger of the at least one event.
The method of Claim 22, wherein determining whether the at least one event is triggered comprises:

obtaining, from the message, a set of configuration parameters associated with the at least one event;

performing the first measurement based on the set of configuration parameters; and

in accordance with a determination that a result of the first measurement meets a condition indicated by the at least one event, determining that the at least one event is triggered.
The method of Claim 22, further comprising:

obtaining, from the message, configuration information for reporting a result of at least one of the first measurement and the second measurement; and

determining the at least one event from the configuration information by at least one of the following:

an index of the configuration information, and

a bitmask associated with the at least one event indicated in the configuration information.
The method of Claim 22, further comprising:

in accordance with a determination that the at least one event is triggered, transmitting a result of at least the first measurement to the second device.
The method of Claim 29, wherein performing one of the operations comprises:

in accordance with a determination that the message indicates that the second measurement is to be initiated at the first device based on the trigger of the at least one event, initiating the second measurement after the transmission of the result of the first measurement.
The method of Claim 29, wherein performing one of the operations comprises:

in accordance with a determination that the message indicates that the second measurement is to be ceased at the first device based on the trigger of the at least one event, ceasing the second measurement after the transmission of the result of at least the first measurement.
The method of Claim 22, wherein performing one of the operations comprises:

in accordance with a determination that the message indicates that the second measurement is to be initiated at the first device based on the trigger of the at least one event, performing the second measurement without transmitting a result of the first measurement to the second device.
The method of Claim 22, wherein performing one of the operations comprises:

in accordance with a determination that the message indicates that the second measurement is to be ceased at the first device based on the trigger of the at least one event, ceasing the second measurement without transmitting a result of at least the first measurement to the second device.
The method of Claim 22, wherein the first device comprises a terminal device, and the second device comprises a network device.
A method comprising:

transmitting, to a first device, a message comprising at least one event related to a service quality of at least one first cell associated with the first device, to cause the first device to perform one of the following operations:

determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell and initiating a second measurement on a second reference signal from at least one second cell, and

determining whether the at least one event is triggered based on the first measurement and ceasing the second measurement.
The method of Claim 35, wherein the service quality comprises a level of at least one of the following:

Synchronization Signal-Reference Signal Receiving Power, SS-RSRP,

Synchronization Signal-Reference Signal Receiving Quality, SS-RSRQ,

Synchronization Signal-Signal-to-Interference and Noise Ratio, SS-SINR, and

Synchronization Signal-Received Signal Strength Indicator, SS-RSSI.
The method of Claim 35, wherein the at least one first cell comprises at least one of the following:

a serving cell of the first device, and

a neighboring cell of the serving cell.
The method of Claim 35, wherein the at least one second cell comprises at least one of the following:

a serving cell of the first device, and

a neighboring cell of the serving cell.
The method of Claim 35, wherein the message further comprises an indication indicating that the second measurement is to be initiated at the first device based on the trigger of the at least one event or the second measurement is to be ceased at the first device based on the trigger of the at least one event.
The method of Claim 35, further comprising:

in response to receiving, from the first device, a further indication for initiating or ceasing a transmission of the first reference signal from the second device to the first device, transmit the first reference signal to the first device.
The method of Claim 35, further comprising:

receiving a result of a first measurement on the first reference signal from the first device;

in accordance with a determination that the at least one event is triggered based on the result, generating, based on the message, a further indication for initiating or ceasing a transmission of the second reference signal from the at least one second cell to the first device; and

transmitting the further indication to the at least one second cell.
The method of Claim 35, wherein the first device comprises a terminal device, and the second device comprises a network device.
An apparatus comprising:

means for receiving, from a second device, a message at least comprising at least one event related to a service quality of at least one first cell associated with the first device;

means for determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell; and

means for in accordance with a determination that the at least one event is triggered, perform one of the following operations: initiating a second measurement on a second reference signal from at least one second cell associated with the first device, and ceasing the second measurement.
An apparatus comprising:

means for transmitting, to a first device, a message comprising at least one event related to a service quality of at least one first cell associated with the first device, to cause the first device to perform one of the following operations:

determining whether the at least one event is triggered based on a first measurement on a first reference signal from the at least one first cell and initiating a second measurement on a second reference signal from at least one second cell, and

determining whether the at least one event is triggered based on the first measurement and ceasing the second measurement.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any of claims 22-34.
A non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any of claims 35-42.