WO2023023967A1

WO2023023967A1 - Relaxed measurement timing configurations

Info

Publication number: WO2023023967A1
Application number: PCT/CN2021/114451
Authority: WO
Inventors: Lei Du; Lars Dalsgaard
Original assignee: Nokia Shanghai Bell Co., Ltd.; Nokia Solutions And Networks Oy; Nokia Technologies Oy
Priority date: 2021-08-25
Filing date: 2021-08-25
Publication date: 2023-03-02
Also published as: CN115734249A

Abstract

Devices, methods, apparatuses and computer readable storage media for relaxation measurements for reference signals. The method comprises: receiving, at a first device and from a second device providing at least a serving cell for the first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device; measuring at least one reference signal from the second device during a basic evaluation period for the reference signal measurement; in accordance with a determination that the set of relaxation criteria is met based on a measurement result, determining a relaxed evaluation period based on the basic evaluation period and a scaling factor; and performing the reference signal measurement for the at least one reference signal during the relaxed evaluation period. In this way, the relaxation RLM/BFD measurements are supported.

Description

RELAXED MEASUREMENT TIMING CONFIGURATIONS

FIELD

Embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to devices, methods, apparatus and computer readable storage media for relaxed measurement timing configurations.

BACKGROUND

In a 5G New Radio (NR) system, relaxation radio resource management (RRM) measurement requirements are specified for UEs operating in RRC_IDLE or RRC_INACTIVE mode. This is mainly for the purpose of powering saving. As specified, the relaxation measurement requirements are respectively defined for the following three cases: 1) measurements fulfilling a low mobility criterion; 2) measurements fulfilling a not-at-cell-edge criterion; and 3) measurements fulfilling both the low mobility and the not-at-cell edge criteria. Specifically, for cases 1) and 2) where only a single criterion is fulfilled, an evaluation period for the UE to perform RRM measurements is extended by applying a scaling factor K1, which allows the UE to perform less frequent RRM measurements. For case 3) , the UE is not required to perform RRM measurements on neighbor cells at all, which enables further power saving for the UE.

To enhance the power saving feature for the UE operating in RRC_CONNECTED mode, it has been proposed to apply similar relaxation measurement requirements on Radio Link Monitoring (RLM) and Beam Failure Detection (BFD) .

SUMMARY

In general, example embodiments of the present disclosure provide a solution of relaxation measurement requirements for RLM and/or BFD.

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 providing a serving cell for the first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device; measure at least one reference signal from the second device during a basic evaluation period for the reference signal measurement; in accordance with a determination that the set of relaxation criteria is met based on a measurement result, determine a relaxed evaluation period based on the basic evaluation period and a scaling factor; and perform the reference signal measurement for the at least one reference signal during the relaxed evaluation period.

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 indicating a set of relaxation criteria related to reference signal measurement for the first device, the message enabling the first device to determine a relaxed evaluation period for reference signal measurement, the first device being served by a serving cell provided by the second device; and transmit, to the first device, at least one reference signal.

In a third aspect, there is provided a method. The method comprises: receiving, at a first device and from a second device providing a serving cell for the first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device; measuring at least one reference signal from the second device during a basic evaluation period for the reference signal measurement; in accordance with a determination that the set of relaxation criteria is met based on a measurement result, determining a relaxed evaluation period based on the basic evaluation period and a scaling factor; and performing the reference signal measurement for the at least one reference signal during the relaxed evaluation period.

In a fourth aspect, there is provided a method. The method comprises: transmitting, at a second device and to a first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device, the message enabling the first device to determine a relaxed evaluation period for reference signal measurement, the first device being served by a serving cell provided by the second device; and; transmitting, to the first device, at least one reference signal.

In a fifth aspect, there is provided a first apparatus. The first apparatus comprises: means for receiving, from a second device providing a serving cell for the first apparatus, a message indicating a set of relaxation criteria related to reference signal measurement for the first apparatus; means for measuring at least one reference signal from the second device during a basic evaluation period for the reference signal measurement; means for in accordance with a determination that the set of relaxation criteria is met based on a measurement result, determining a relaxed evaluation period based on the basic evaluation period and a scaling factor; and means for means for performing the reference signal measurement for the at least one reference signal during the relaxed evaluation period.

In a sixth aspect, there is provided a second apparatus. The second apparatus comprises: means for transmitting, to a first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device, the message enabling the first device to determine a relaxed evaluation period for reference signal measurement, the first device being served by a serving cell provided by the second apparatus; and means for transmitting, to the first device, at least one reference signal.

In a seventh aspect, there is provided a computer readable medium having a computer program stored thereon which, when executed by at least one processor of a device, causes the device to carry out the method according to the third aspect.

In an eighth aspect, there is provided a computer readable medium having a computer program stored thereon which, when executed by at least one processor of a device, causes the device to carry out the method according to the fourth aspect.

Other features and advantages of the embodiments of the present disclosure will also be apparent from the following description of specific embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of embodiments of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure are presented in the sense of examples and their advantages are explained in greater detail below, with reference to the accompanying drawings, where

FIG. 1 illustrates an example network system in which example embodiments of the present disclosure can be implemented;

FIG. 2 shows a signaling chart illustrating an example relaxed measurement process according to some example embodiments of the present disclosure;

FIG. 3 shows a signaling chart illustrating another example relaxed measurement process according to some example embodiments of the present disclosure;

FIG. 4 shows a signaling chart illustrating still another example relaxed measurement process according to some example embodiments of the present disclosure;

FIG. 5 illustrates a flowchart of an example method according to some example embodiments of the present disclosure;

FIG. 6 illustrates a flowchart of an example method according to some example embodiments of the present disclosure;

FIG. 7 shows a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

FIG. 8 shows a block diagram of an example computer readable medium in accordance with some 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) , Integrated Access and Backhaul (IAB) node, a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology. The network device is allowed to be defined as part of a gNB such as for example in CU/DU split in which case the network device is defined to be either a gNB-CU or a gNB-DU.

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.

As previously mentioned, the UE under RRC_IDLE or RRC_INACTIVE mode is allowed to relax RRM measurements by extending the detection period, the measurement period, and evaluation period based on a scaling factor K1, if the UE has a low mobility or the serving cell quality is good enough. Table 1 shows an example configuration of relaxed NR intra-frequency measurement in Rel-16.

Table 1. Example configuration of relaxed NR intra-frequency measurement

When operating in RRC_CONNECTED mode, the UE performs RLM in the active bandwidth part (BWP) based on reference signals (RSs) configured by the network, such as, synchronization signaling block (SSB) , channel state information RS (CSI-RS) and so on. The UE monitors the RS configured as RLM-RS resource (s) in order to evaluate the downlink radio link quality of the primary cell (PCell) and the primary secondary cell (PSCell) and other cells configured to be monitored. It has been proposed to reuse the principle of relaxed RRM measurement requirements for the UE in RRC_IDLE or RRC_INACTIVE mode to the RLM/BFD measurements performed by the UE in RRC-CONNECTED mode. For example, whether a relaxed RLM/BFD measurement is allowed at the UE in RRC-CONNECTED mode may depend on the serving cell quality and the mobility state of the UE. If the serving cell quality is good enough (e.g., exceeding a cell quality threshold) or the UE has low mobility, the UE is allowed to relax the RLM/BFD measurements by extending the measurement period based on a scaling factor K1.

However, such a principle cannot be completely applied for the UE in RRC-CONNECTED mode, when both the low mobility and the not-at-cell edge criteria are fulfilled. This is because in this case, the UE is not required to measure neighbor cells and no neighbor cell measurement requirement applies. This is reasonable for the UE operating in RRC_IDLE/INACTIVE mode to save power, but it is not sensible for the RLM or BFD measurements in RRC_CONNECTED mode as the UE needs to continually and closely monitors the channel quality of the serving cell to ensure the data transmission performance. Otherwise, the UE is unable to detect a potential RLM or beam failure in time due to potential channel variation or degradation over time and the user experience of the UE will be significantly impacted.

In order to solve the above and other potential problems, embodiments of the present disclosure provide a mechanism for relaxation of measurement for RLM or BFD. According to the mechanism, the measurement requirements of RLM and/or BFD can be relaxed depending on whether only one or two conditions enabling the RLM/BFD relaxation are fulfilled. In addition, different relaxation factors for scaling the evaluation period for RLM and/or BFD are applied depending on whether one or both relaxation conditions are fulfilled. In this way, the UE is allowed to perform RLM/BFD measurements based on a relaxed evaluation period in a case where one or both the low mobility and the serving cell quality criteria are fulfilled. The relaxed evaluation period applied in the case where both criteria are fulfilled should be no shorter than the relaxed evaluation period applied in the case where only a single criterion is fulfilled.

It should be understood that the power saving of the UE can also be improved by reducing the number of related RLM/BFD measurements, for example, the number of measurement samples, in a certain evaluation period. Additionally or alternatively, the relaxed evaluation period provided in the present disclosure can be used in combination with the reduced number of measurement samples.

FIG. 1 illustrates an example network system 100 in which example embodiments of the present disclosure can be implemented. As shown in FIG. 1, the communication network 100 may include a terminal device 110 (hereinafter may also be referred to as a UE 110 or a first device 110) and a network device 120 (hereinafter may also be referred to as a gNB 120 or a second device 120) . The network device 120 can manage a serving cell 102 for the terminal device 110. The terminal device 110 and the network device 120 can communicate with each other in the coverage of the cell 102.

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, terminal devices and additional devices adapted for implementations of the present disclosure.

The network device 120 may configure at least one RS resource to the terminal device 110 for performing RLM and/or BFD. The RS source may include, but not limited to, SSB, CSI-RS and so on. As an example, the network device 120 may configure a first RS resource for RLM (hereinafter which may be also referred to as RLM-RS resources) and a second RS resource for BFD ( (hereinafter which may be also referred to as BFD-RS resources) to the terminal device 110. As another example, the network device 120 may configure only one RS resources which are monitored for both RLM and BFD. As another example, the network device 120 may configure only one of the RLM-RS resources and the BFD-RS resources to the terminal device 110. In some example embodiments, for each of the RLM and the BFD, the network device 120 may configure a plurality of RS resources.

The terminal device 110 performs RLM and/or BFD on the configured RS resources during a basic evaluation period. Considering RLM as an example, the terminal device 110 may evaluate the radio link quality based on thresholds Q _out and Q _in. Specifically, the terminal device 110 is assumed to collect a number of measurement samples (e.g., up to 10) within a certain time period. Specifically, the UE may evaluate, by using the averaged results of samples, the radio link quality against an internal block error rate (BLER) mapping during the evaluation period. For example, if the UE determines that an estimated channel quality corresponds to a BLER level higher than, e.g., 10%or beyond (Q _out) , the UE will send an indication of out-of-sync (OoS) , from the lower layer to the upper layer of the UE. The threshold Q _out is defined as a level at which the downlink radio link cannot be reliably received and may correspond to the out-of-sync block error rate, BLER _out (e.g., 10%) . A counter N310 of the UE will increment for each indication of OoS from the lower layer to the upper layer. If the counter N310 has reached to a preconfigured maximum number, the UE may then start a timer T310. When the timer T310 is running, the UE continues to evaluate the channel quality and estimate the BLER level. If the BLER level corresponding to the estimated channel quality become better and with higher reliability than e.g. Q _in (2%) (before expiration of the timer T310) , an indication of in-sync (IS) , will be sent from the lower layer to the upper layer, which indicates that the channel condition has been improved. The threshold Q _in is defined as a level at which the downlink radio link quality can be received with significantly higher reliability than at Q _out and may correspond to the in-sync block error rate, BLER _in (e.g., 2%) . In this case, the timer T310 will be stopped. If the channel condition is not improved before the timer T310 expires, the UE may then declare radio link failure (RLF) .

Based on the minimum requirement for RLM-RS measurements based on e.g., SSB, the terminal device 110 needs to evaluate whether the downlink radio link quality on the configured RLM-RS resources estimated within the last evaluation period T _{Evaluate_out_SSB} becomes worse than the threshold Q _{out_SSB} for the evaluation period T _{Evaluate_out_SSB}. The UE also needs to evaluate whether the downlink radio link quality on the configured RLM-RS resources estimated within the last evaluation period T _{Evaluate_in_SSB} becomes better than the threshold Q _{in_SSB} for the evaluation period T _{Evaluate_in_SSB}. Table 2 shows the evaluation periods T _{Evaluate_out_SSB} and T _{Evaluate_in_SSB} for FR1, and table 3 shows the evaluation periods T _{Evaluate_out_SSB} and T _{Evaluate_in_SSB} for FR2 as certain examples.

Table 2. Evaluation periods T _{Evaluate_out_SSB} and T _{Evaluate_in_SSB} for FR1

Table 3. Evaluation periods T _{Evaluate_out_SSB} and T _{Evaluate_in_SSB} for FR2

As shown in tables 2 and 3, for FR1 and FR2, the length of the evaluation period depends on N which represents the RX beam scaling factor in FR2 and P which represents the sharing scaling factor considering the overlapping status between RLM-RS resource and measurement gaps and SSB-based measurement timing configuration (SMTC) occasions. The length of the evaluation period may also depend on the RLM-RS resources and SMTC occasions configured for the terminal device 110.

The network device 120 may configure at least one relaxation criterion in terms of evaluation period to the terminal device 110. For example, the at least one relaxation criterion may include a first criterion related to the mobility of the terminal device 110, and a second criterion related to the serving cell quality for the terminal device 110. In some example embodiments, only one of the first and second criteria may be configured to the terminal device 110. In some other example embodiments, both of the first and second criteria may be configured to the terminal device 110. The at least one relaxation criterion may be indicated in a first message transmitted from the network device 120, for example, a RRC reconfiguration message. It should be understood that any other message is also suitable for implementing the example embodiments.

As such, the terminal device 110 is allowed to relax RS measurement based on whether the configured relaxation criterion is fulfilled. In particular, depending on the configured relaxation criterion or criteria, there may be four possible conditions for the terminal device 110:

1) only the first criterion related to the mobility of the terminal device 110 is configured, and the first criterion is fulfilled, if the mobility of the terminal device 110 is below a mobility threshold;

2) only the second criterion related to the serving cell quality for the terminal device 110 is configured, and the second criterion is fulfilled, if the serving cell quality exceeds a cell quality threshold;

3) both the first criterion and the second criterion are configured, and only one of the two configured criteria is fulfilled; and

4) both the first criterion and the second criterion are configured and fulfilled.

In some example embodiments, different relaxation factors may be applied by the terminal device 110 for scaling a basic evaluation period according to the configured criteria and different conditions. Table 4 shows an example mapping between various conditions about the relaxation criterion and the relaxation factor K _S.

Table 4. Mapping between conditions about relaxation criterion and relaxation factors K _S

As shown in Table 4, there are three relaxation factors, including the first criterion corresponding to the first factor K1, the second criterion corresponding to the second factor K2, and the third factor K3 that is applied when both of the first criterion and the second criterion are fulfilled. The third factor K3 may be specified, or alternatively, derived from the first factor K1 and the second factor K2. For example, the third factor K3 may be equal to a larger one of K1 and K2 denoted by max (K1, K2) , a product of K1 and K2 denoted by (K1*K2) , a sum of K1 and K2 denoted by (K1+K2) , and so on.

Table 5 shows an example relaxed configuration of the evaluation period for FR1, where K _S represents the relaxation factor. It should be understood that the relaxed configuration shown in table 5 is mainly for a case of shorter DRX cycles, however this is given as illustrative example without any limitation. The principles for relaxed measurement timing configurations are applicable for any DRX cycle including the case where no DRX is in use and/or longer DRX cycles.

Table 5. Evaluation period T _{Evaluate_out_SSB} and T _{Evaluate_in_SSB} for FR1

Table 6 shows another example relaxed configuration of the evaluation period for FR1, where K _both represents the third factor K3. The terminal device 110 may evaluate whether the downlink radio link quality on the configured RS resource estimated over the last evaluation period T _{Evaluate_out_SSB} becomes worse than the threshold Q _{out_SSB} for evaluation period T _{Evaluate_out_SSB}. The terminal device 110 may evaluate whether the downlink radio link quality on the configured RS resource estimated over the last evaluation period T _{Evaluate_in_SSB} becomes better than the threshold Q _{in_SSB} for evaluation period T _{Evaluate_in_SSB}. It should be understood that the relaxed configuration shown in table 6 is mainly for a case of shorter DRX cycles, however this is given as illustrative example without any limitation. The principles for relaxed measurement timing configurations are applicable for any DRX cycle including the case where no DRX is in use and/or long DRXer cycles. It can be considered that the channel condition is more robust when both conditions are fulfilled as compared to only one condition is fulfilled, and thus an additional relaxed evaluation period for RLM/BFD measurements is allowed for the terminal device 110.

Table 6. Evaluation period T _{Evaluate_out_SSB} and T _{Evaluate_in_SSB} for FR1

In some example embodiments, the terminal device 110 may determine the evaluation period for RLM/BFD based on tables 4-6 depending on the relaxed criteria configured by the network device 120 and the condition about the configured relaxed criteria.

According to the example embodiments of the present disclosure, the UE is allowed to relax measurement requirements for RLM/BFD based on different conditions. As such, the power consumption of the UE can be reduced without introducing negative impact on the network system.

Depending on the communication technologies, the communication 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.

Principle and implementations of the present disclosure will be described in detail below with reference to FIGs. 2 to 6. FIG. 2 shows a signaling chart illustrating an example relaxed measurement process 200 according to some example embodiments of the present disclosure. The process 200 may involve the terminal device 110 and the second device 120 as shown in FIG. 1. For the purpose of discussion, the process 200 will be described with reference to FIG. 1.

In the process 200, the terminal device 110 communicates 202 with the network device 120 in the RRC_CONNECTED mode. The network device 120 may configure at least one RS resource for the terminal device 110. By way of example, in the description of the process 200, the network device 120 configures a first set of RLM-RS, e.g., SSB to the terminal device 110 for performing RLM. It should be understood that the SSB is given as illustrative, any other RS resources are also suitable for implementing the example embodiments. Moreover, the process 200 is also applicable for BFD. Hence, the present disclosure is not limited in this regard.

The network device 120 may configure a set of relaxation criteria for relaxing RS measurement to the terminal device 110. The set of relaxation criteria may include, for example, the first criterion related to the mobility of the terminal device 110 (which may be also referred to the low mobility criterion) and the second criterion related to the serving cell quality (which may be also referred to the good serving cell quality criterion) .

The network device 120 transmits 204, to the terminal device 110, a first message for indicating the configured set of relaxation criteria including the first criteria and the second criteria. In some example embodiments, the first message may also indicate that the UE is allowed to further relax the measurements when both criteria are fulfilled. In some example embodiments, the first message may also indicate the at least one RS resource configured by the network device 120. The first message may be, for example, a RRC reconfiguration message or any other message suitable for indicating the set of relaxation criteria.

The network device 120 then transmits 206 the RLM-RS on the at least one RS resource. The terminal device 110 measures 208 the RLM-RS and evaluate the radio link quality during a basic evaluation period T _Evaluate. In the context of the present disclosure, the basic evaluation period T _Evaluate refers to a non-relaxed evaluation period applied based on non-relaxed measurement requirements.

The terminal device 110 determines whether the configured criteria are fulfilled and determines 210 a relaxed evaluation period T _{Evaluate_relaxation} for the RLM-RS measurement based on the measurement result.

If only one of the first criterion and the second criterion is fulfilled as determined in 210, the terminal device 110 may determine a relaxed evaluation period T _{Evaluate_single} based on a corresponding one of the first factor K1 or the second factor K2. For example, if the terminal device 110 determines that the mobility of the terminal device 110 is below a predefined mobility threshold but the serving cell quality does not exceed a predefined cell quality threshold, then the terminal device 110 may determine that the first criterion is fulfilled while the second criterion is not fulfilled. In this case, the relaxed evaluation period T _{Evaluate_single} may be determined by extending the basic evaluation period T _Evaluate with the first factor K1.

For another example, if the terminal device 110 determines that the serving cell quality exceeds the predefined cell quality threshold but the mobility of the terminal device 110 is not below the predefined mobility threshold, then the terminal device 110 may determine that the second criterion is fulfilled while the first criterion is not fulfilled. In this case, the relaxed evaluation period T _{Evaluate_single} may be determined by extending the basic evaluation period T _Evaluate with the second factor K2.

In the above cases, the terminal device 110 may then perform the RLM-RS measurement on the configured RS resource based on the relaxed evaluation period T _{Evaluate_single}. As shown in sub-process 215, the network device 120 may continue to transmit 216 the RLM-RS on the configured RS resource. Upon receipt of the RLM-RS, the terminal device 110 may measure 218 the RLM-RS and evaluate the radio link quality during the relaxed evaluation period T _{Evaluate_single}.

Alternatively, if both of the first criterion and the second criterion are fulfilled, as determined in 220, the terminal device 110 may determine a relaxed evaluation period T _{Evaluate_both} based on the third factor K3.

The evaluation period T _{Evaluate_both} relaxed based on the third factor K3 should not be shorter than the evaluation period T _{Evaluate_single} relaxed based on either the first factor K1 or the second factor K2. In some example embodiments, the third factor K3 may be derived based on the first factor K1 and the second factor K2. For example, K3 may be equal to max (K1, K2) , (K1*K2) , (K1+K2) or the like. In this way, when both criteria are fulfilled, the terminal device 110 is capable of relaxing the measurement requirements even more as compared to when only a single criterion is fulfilled.

In the above case, the terminal device 110 may then perform the RLM-RS measurement on the configured RS resource based on the relaxed evaluation period T _{Evaluate_both}. As shown in sub-process 220, the network device 120 may continue to transmit 222 the RLM-RS on the configured RS resource. Upon receipt of the RLM-RS, the terminal device 110 may measure 224 the RLM-RS and evaluate the radio link quality during the relaxed evaluation period T _{Evaluate_both}.

In some example embodiments where the network device 120 configures a plurality of RS resources to the terminal device 110, if the terminal device 110 determines that both of the first criterion and second criterion are fulfilled on any of the plurality of RS resources, the terminal device 110 may perform the relaxed RLM measurement on either the RS resources on which both of the first criterion and second criterion are fulfilled, or on all of the plurality of RS resources.

In some example embodiments where the network device 120 configures a plurality of RS resources to the terminal device 110, if the terminal device 110 determines that both of the first criterion and second criterion are fulfilled on one of the plurality of RS resources for a certain time period, the terminal device 110 may keep performing relaxed RLM measurements on the one RS resource while suspending the RLM measurements on the rest of the plurality of RS resources.

In some example embodiments, the terminal device 110 may relax the RLM/BFD measurement requirements in a step-wise way. For example, the evaluation period may be further extended based on how long the one or both criteria have been met.

FIG. 3 shows a signaling chart illustrating another example relaxation measurement process 300 according to some example embodiments of the present disclosure. The process 300 may involve the terminal device 110 and the second device 120 as shown in FIG. 1. For the purpose of discussion, the process 300 will be described with reference to FIG. 1.

In the process 300, the terminal device 110 communicates 302 with the network device 120 in the RRC_CONNECTED mode. The network device 120 may configure multiple RS resources for RLM and BFD to the terminal device 110. By way of example, in the description of the process 300, the network device 120 configures a first RS resource to the terminal device 110 for performing RLM, and configures a second RS resource for performing BFD.

The network device 120 may configure a set of relaxation criteria for relaxing RLM-RS measurement and BFD measurement to the terminal device 110. The set of relaxation criteria may include, for example, the first criterion related to the mobility of the terminal device 110 (which may be also referred to the low mobility criterion) and the second criterion related to the serving cell quality (which may be also referred to the serving cell quality criterion) . In the example as shown in FIG. 3, the network device 120 configures both the first and second criterion for RLM and BFD.

The network device 120 transmits 304, a first message indicating the first RS resource and the set of relaxation criteria for RLM to the terminal device 110. The network device 120 transmits 306, a second message indicating the second RS resource and the set of relaxation criteria for BFD to the terminal device 110. The first message and second message may be one or more RRC reconfiguration messages.

It should be understood that the signaling for configuring RS resources and relaxation criteria is given as illustrative, in some other cases, more or less signaling can be used. The present disclosure is not limited in this regard.

The network device 120 transmits 308 the RLM-RS on the first RS resource, and transmits 310 the BFD-RS on the second RS resource. The terminal device 110 measures 312 the RLM-RS and the BFD-RS and evaluate the radio link quality during a basic evaluation period T _Evaluate.

The terminal device 110 determines whether the configured criteria are fulfilled on the first RS resource and the second RS resource based on the measurement result. The terminal device 110 determines 314 the relaxed evaluation period T _{Evaluate_relaxation} based on the measurement result.

If only one of the first criterion and the second criterion is fulfilled, the terminal device 110 may determine a relaxed evaluation period T _{Evaluate_single} based on a corresponding one of the first factor K1 and the second factor K2. For example, if the terminal device 110 determines that the mobility of the terminal device 110 is below a predefined mobility threshold but the serving cell quality does not exceed a predefined cell quality threshold, then the terminal device 110 may determine that the first criterion is fulfilled while the second criterion is not fulfilled. In this case, the relaxed evaluation period T _{Evaluate_single} may be determined by extending the basic evaluation period T _Evaluate with the first factor K1.

In the above cases, the terminal device 110 may then perform the RLM-RS measurement on the first RS resource and the BFD-RS measurement on the second RS resource based on the relaxed evaluation period T _{Evaluate_single}. In one example, T _{Evaluate_single_RLM} is used for relaxed evaluation period for RLM and T _{Evaluate_single_BFD} is used for relaxed evaluation period for BFD. As shown in sub-process 315, the network device 120 may continue to transmit 316 the RLM-RS on the first RS resource, and continue to transmit 318 the BFD-RS on the second RS resource.

Upon receipt of the RSs, the terminal device 110 may measure 320 of the RLM-RS and BFD-RS and evaluate the radio link quality during the relaxed evaluation period T _{Evaluate_single}.

Alternatively, if both of the first criterion and the second criterion are fulfilled, the terminal device 110 may determine a relaxed evaluation period T _{Evaluate_both} based on the third factor K3. The terminal device 110 may then perform the RLM-RS measurement on the first RS resource and/or the BFD-RS measurement on the second RS resource based on the relaxed evaluation period T _{Evaluate_both}. As shown in sub-process 325, the network device 120 may continue to transmit 326 RLM-RSs and BFD-RSs on the configured RS resources.

Upon receipt of the RLM-RSs and the BFD-RS, the terminal device 110 may measure 328 at least one of the RLM-RS and BFD-RS and evaluate the radio link quality during the relaxed evaluation period T _{Evaluate_both}. In some example embodiments, the terminal device 110 may perform one of the RLM-RS measurement and the BFD-RS measurement. For example, the terminal device may measure only the BFD-RSs and evaluate the radio link quality during the relaxed evaluation period T _{Evaluate_both}, and suspend 330 the RLM measurements on the first RS resources.

In some example embodiments, if the set relaxation criteria is no longer fulfilled, the terminal device 110 may leave the relaxation BFD measurement requirements, while re-initiate the RLM measurements without relaxation.

FIG. 4 shows a signaling chart illustrating still another example relaxation measurement process 400 according to some example embodiments of the present disclosure. The process 400 may involve the terminal device 110 and the second device 120 as shown in FIG. 1. For the purpose of discussion, the process 400 will be described with reference to FIG. 1.

In the process 400, the terminal device 110 communicates 402 with the network device 120 in the RRC_CONNECTED mode. The network device 120 may configure a plurality of RS resources to the terminal device 110 for performing RLM. For example, a plurality of RS resources may include a first RLM-RS resource and a second RLM-RS resource. It should be understood that the number of RS resources is given only for illustrative purpose, and the process 400 is also applicable for BFD, hence, the present disclosure is not limited in this regard.

The network device 120 may configure a set of relaxation criteria for relaxing RLM-RS measurement to the terminal device 110. The set of relaxation criteria may include, for example, the first criterion related to the mobility of the terminal device 110 (which may be also referred to the low mobility criterion) and the second criterion related to the serving cell quality (which may be also referred to the serving cell quality criterion) . In the example as shown in FIG. 4, the network device 120 configures both the first and second criterion for RLM.

The network device 120 transmits 404, a message indicating the first and second RLM-RS resources, and the set of relaxation criteria for RLM to the terminal device 110. The message may be a RRC reconfiguration message. It should be understood that the signaling for configuring RS resources and relaxation criteria is given as illustrative, in some other cases, more signaling can be used. The present disclosure is not limited in this regard.

The network device 120 transmits 406 a first RLM-RS on the first RLM-RS resource, and transmits 408 a second RLM-RS on the second RLM-RS resource. The terminal device 110 measures 410, 412 the first RLM-RS and the second RLM-RS and evaluate the radio link quality during a basic evaluation period T _Evaluate.

The terminal device 110 determines whether the configured criteria are fulfilled on the first RLM-RS resource and the second RLM-RS resource based on the measurement result. The terminal device 110 determines 414 at least one relaxed evaluation period T _{Evaluate_relaxation} for the RLM-RS measurements on the configured RS resources.

In some example embodiments where not all the configured relaxation criteria are fulfilled on the configured RS resources, the terminal device 110 may determine the evaluation period per RLM-RS. For example, both criteria are fulfilled on the first RLM-RS resource, while only one of the criteria (e.g., the second criteria) is fulfilled on the second RLM-RS resource. The terminal device 110 determines the relaxed evaluation period T _{Evaluate_both} based on the third factor K3. The terminal device 110 may further determine the relaxed evaluation period T _{Evaluate_single} based on the second factor K2. The terminal device 110 may then perform the RLM-RS measurement on the first RLM-RS resource based on the relaxed evaluation period T _{Evaluate_both} and the RLM-RS measurement on the second RLM-RS resource based on the relaxed evaluation period T _{Evaluate_single}.

The above embodiments are shown in sub-process 415. The network device 120 may continue to transmit 416 the first RLM-RS on the first RLM-RS resource, and continue to transmit 418 the second RLM-RS on the second RLM-RS resource.

Upon receipt of the RLM-RSs, the terminal device 110 may measure 420 the first RLM-RS and evaluate the radio link quality during the relaxed evaluation period T _{Evaluate_both}. In addition, the terminal device 110 may measure 422 the second RLM-RS and evaluate the radio link quality during the relaxed evaluation period T _{Evaluate_single.}

Alternatively, in the example embodiments where both criteria are fulfilled on the first RLM-RS resource while only one of the criteria is fulfilled on the second RLM-RS resource, the terminal device 110 may measure the RLM-RS measurement on the first RLM-RS resource and evaluate the radio link quality based on the relaxed evaluation period T _{Evaluate_both}, and suspend the RLM-RS measurement on the second RLM-RS resource. In some example embodiments, this may be allowed if both criteria are fulfilled on the first RLM-RS resource for a certain time period.

The above embodiments are shown in sub-process 425, where the network device 120 may continue to transmit 426 the first RLM-RS on the first RLM-RS resource, and continue to transmit 428 the second RLM-RS on the second RLM-RS resource. Upon receipt of the RLM-RSs, the terminal device 110 may measure 430 the first RLM-RS and evaluate the radio link quality during the relaxed evaluation period T _{Evaluate_both}. In addition, the terminal device 110 may suspend 432 the RLM-RS measurement on the second RLM-RS resource.

In some example embodiments, the terminal device 110 may perform RLM-RS measurements based on the relaxed evaluation period T _{Evaluate_both} only if both criteria are fulfilled on all the RLM-RSs. In these embodiments, the relaxed evaluation period T _{Evaluate_single} is applied as long as either one of the criteria is fulfilled on any of the configured RLM-RSs.

FIG. 5 illustrates a flowchart of an example method 500 according to some example embodiments of the present disclosure. The method 500 can be implemented at a first device, e.g., the terminal device 110 described with reference to FIG. 1. For the purpose of discussion, the method 500 will be described with reference to FIG. 1.

At 510, the first device receives, from a second device providing at least a serving cell for the first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device.

In some example embodiments, the reference signal measurement may be associated with at least one of RLM and BFD.

In some example embodiments, the set of relaxation criteria may comprise a first criterion related to a mobility of the first device, and a second criterion related to a serving cell quality for the first device.

At 520, the first device measures at least one reference signal from the second device during a basic evaluation period for the reference signal measurement.

At 530, the first device determines whether the set of relaxation criteria is met based on a measurement result.

If the at least one relaxation criterion is met, the first device, at 540, determines a relaxed evaluation period based on the basic evaluation period and a scaling factor.

In some example embodiments, the first criterion may correspond to a first factor for scaling the basic evaluation period, the second criterion may correspond to a second factor for scaling the basic evaluation period. The scaling factor may comprise one of the first factor, the second factor, and a third factor. In an example embodiment, the third factor may correspond to both of the first criterion and the second criterion being met, and may be predefined/preconfigured or derived from the first factor and the second factor. For example, the third factor K3 may be equal to max (K1, K2) , (K1*K2) , (K1+K2) or the like. The evaluation period relaxed based on the third factor K3 should not be shorter than the evaluation period relaxed based on either the first factor K1 or the second factor K2.

In some example embodiments, the third factor may comprise at least one of the maximum of the first factor and the second factor, a sum of the first factor and the second factor, and a product of the first factor and the second factor.

In some example embodiments, the first factor and the second factor may be preconfigured at the first device and the second device.

In some example embodiments, the first device may receive, from the second device, a message for configuring a mapping relation between a combination of the relaxation criteria in the set and the first factor and the second factor. The mapping relation may also be pre-defined at both UE and network side.

In some example embodiments, the first device may receive, from the second device, a message for enabling the further relaxation of measurements when both criteria are fulfilled.

To determine whether the set of relaxation criteria is met, the first device may evaluate whether the mobility of the first device is below a mobility threshold. If the mobility of the first device is below a mobility threshold, the first device determines that the first criterion is met. In addition, the first device may determine whether the serving cell quality for the first device exceeds a cell quality threshold. If the serving cell quality for the first device exceeds a cell quality threshold, the first device determines that the second criterion is met. The first device may determine the relaxed evaluation period by scaling the basic evaluation period with the scaling factor.

In an example embodiment, the first device may scale the basic evaluation period with the scaling factor after the first criterion or/and the second criterion are met for a predetermined time period.

In some example embodiments where the first device is configured for a plurality of reference signals, to determine the relaxed evaluation period, the first device may determine whether the set of criteria is met on the plurality of reference signals. If the set of criteria is met on the plurality of reference signals, the first device determines the relaxed evaluation period based on the basic evaluation period and the scaling factor.

In some example embodiments where the first device is configured for a plurality of reference signals, to determine the relaxed evaluation period, the first device may determine whether the set of criteria is met on a first subset of the plurality of reference signals. If the set of criteria is met on a first subset of the plurality of reference signals, the first device determine a first relaxed evaluation period based on the basic evaluation period and the scaling factor.

In the above example embodiments, the first device may further determine one of the set of criteria is met on a second subset of the plurality of reference signals. If one of the set of criteria is met on a second subset of the plurality of reference signals, the first device then determine a second relaxed evaluation period by scaling the basic evaluation period based on one of the first factor and the second factor.

At 550, the first device performs the reference signal measurement on the at least one reference signal during the relaxed evaluation period.

In some example embodiments where the at least one reference signal is configured for one of RLM and BFD, and at least one further reference signal is configured for the other one of the RLM and BFD, the first device may perform one of the RLM and BFD on the at least one reference signal based on the relaxed evaluation period. Additionally, the first device may refrain from performing the other one of the RLM and BFD on the at least one further reference signal.

Additionally, in the above embodiments, the first device may determine whether the set of relaxation criteria is met on the one of the RLM and BFD for a predetermined time period. If so, the first device performs the one of the RLM and BFD. Additionally, the first device may refrain from performing the other one of the RLM and BFD.

In some example embodiments where the first device is configured for a plurality of reference signals and the set of criteria is met on a first subset of the plurality of reference signals, the first device may perform the reference signal measurement on the first subset of the plurality of reference signals during the first relaxed evaluation period.

Additionally, in the above embodiments, one of the set of criteria is met on a second subset of the plurality of reference signals, and a second relaxed evaluation period is determined by scaling the basic evaluation period based on one of the first factor and the second factor, the first device may perform the reference signal measurement on the second subset of the plurality of reference signals during the second relaxed evaluation period.

FIG. 6 illustrates a flowchart of an example method 600 according to some example embodiments of the present disclosure. The method 600 can be implemented at a second device, e.g., the network device 120 described with reference to FIG. 1. For the purpose of discussion, the method 600 will be described with reference to FIG. 1.

At 610, the second device transmits, to a first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device. The first device is served by at least a serving cell provided by the second device. The message may enable the first device to determine a relaxed evaluation period for reference signal measurement.

In some example embodiments, the reference signal measurement is associated with at least one of radio link monitoring and beam failure detection.

In some example embodiments, the second device may configure at least one first reference signal resource for RLM and at least one second reference signal resource for BFD to the first device.

Additionally or alternatively, the second device may configure a plurality reference signal resources for either one or both of the RLM and the BFD.

In some example embodiments, the message may enable the first device to determine the relaxed evaluation period by applying a scaling factor associated with the set of criteria to a basic evaluation period for the reference signal measurement. The first criterion may correspond to a first factor for scaling the basic evaluation period, the second criterion may correspond to a second factor for scaling the basic evaluation period. The scaling factor may be one of the first factor, the second factor, and a third factor. In an example embodiment, the third factor may correspond to both criterion being met, and may be predefined/preconfigured or derived from the first factor and the second factor.

In some example embodiments, the second device may transmit, to the first device, a message for configuring a mapping relation between a combination of the relaxation criteria in the set and the first factor and the second factor. In this case, the mapping is dynamically configured by the second device.

In some example embodiments, the second device may transmit, to the first device, a message for enabling the further relaxation of measurements when both criteria are fulfilled.

At 620, the second device transmits, to the first device, at least one reference signal. The first device may measure the reference signal during a basic evaluation period. Once the configured at least one relaxation criterion is met, the first device may perform reference signal measurement based on a relaxed evaluation period.

In some example embodiments, a first apparatus capable of performing the method 500 (for example, the terminal device 110) may comprise means for performing the respective steps of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. In some embodiments, the means may comprise at least one processor and at least one memory including computer program code. The at least one memory and computer program code are configured to, with the at least one processor, cause performance of the first apparatus.

In some example embodiments, the first apparatus comprises: means for receiving, from a second device providing a serving cell for the first apparatus, a message indicating a set of relaxation criteria related to reference signal measurement for the first apparatus; means for measuring at least one reference signal from the second device during a basic evaluation period for the reference signal measurement; means for in accordance with a determination that the set of relaxation criteria is met based on a measurement result, determining a relaxed evaluation period based on the basic evaluation period and a scaling factor; and means for performing the reference signal measurement for the at least one reference signal during the relaxed evaluation period.

In some example embodiments, the set of relaxation criteria comprises a first criterion related to a mobility of the first apparatus, and a second criterion related to a serving cell quality for the first apparatus.

In some example embodiments, the first criterion corresponds to a first factor for scaling the basic evaluation period, the second criterion corresponds to a second factor for scaling the basic evaluation period, and the scaling factor comprises one of the first factor, the second factor, and a third factor. In an example embodiment, the third factor may correspond to both of the first criterion and the second criterion being met, and may be predefined/preconfigured or derived from the first factor and the second factor.

In some example embodiments, the third factor comprises one of the following: the maximum of the first factor and the second factor, a sum of the first factor and the second factor, and a product of the first factor and the second factor.

In some example embodiments, the first factor and the second factor are preconfigured at the first apparatus and the second device.

In some example embodiments, the first apparatus further comprises: means for receiving, from the second device, a message for configuring a mapping relation between a combination of the relaxation criteria in the set and the first factor and the second factor.

In some example embodiments, the means for determining the relaxed evaluation period comprises: means for in accordance with a determination that the mobility of the first apparatus is below a mobility threshold, determining that the first criterion is met; means for in accordance with a determination that the serving cell quality for the first apparatus exceeds a cell quality threshold, determining that the second criterion is met; and means for determining the relaxed evaluation period by scaling the basic evaluation period with the scaling factor.

In some example embodiments, the basic evaluation period is scaled with the scaling factor after the first criterion or/and the second criterion are met for a predetermined time period.

In some example embodiments, the at least one reference signal is configured for one of radio link monitoring and beam failure detection, and at least one further reference signal is configured for the other one of the radio link monitoring and the beam failure detection, and the means for performing the reference signal measurement comprises: means for performing one of the radio link monitoring and the beam failure detection on the at least one reference signal based on the relaxed evaluation period; and means for refraining from performing the other one of the radio link monitoring and the beam failure detection on the at least one further reference signal.

In some example embodiments, the means for performing the reference signal measurement comprises: means for in accordance with a determination that the set of relaxation criteria is met on the one of the radio link monitoring and the beam failure detection for a predetermined time period, performing the reference signal measurement.

In some example embodiments, the means for determining the relaxed evaluation period comprises: means for in accordance with a determination that the set of criteria is met on the plurality of reference signals, determining the relaxed evaluation period based on the basic evaluation period and the scaling factor.

In some example embodiments, the means for determining the relaxed evaluation period comprises: means for in accordance with a determination that the set of criteria is met on a first subset of the plurality of reference signals, determining a first relaxed evaluation period based on the basic evaluation period and the scaling factor.

In some example embodiments, the means for performing the reference signal measurement comprises: means for performing the reference signal measurement on the first subset of the plurality of reference signals during the first relaxed evaluation period.

In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that one of the set of criteria is met on a second subset of the plurality of reference signals, refraining from performing the reference signal measurement on the second subset of the plurality of reference signals.

In some example embodiments, the means for determining the relaxed evaluation period comprises: means for in accordance with a determination that one of the set of criteria is met on a second subset of the plurality of reference signals, determining a second relaxed evaluation period by scaling the basic evaluation period based on one of the first factor and the second factor; and means for performing the reference signal measurement on the second subset of the plurality of reference signals during the second relaxed evaluation period.

In some example embodiments, the first apparatus further comprises: means for receiving, from the second device, a message for enabling further relaxation of measurements when the set of relaxation criteria is fulfilled.

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

In some example embodiments, a second apparatus capable of performing the method 600 (for example, the network device 120) may comprise means for performing the respective steps of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. In some embodiments, the means may comprise at least one processor and at least one memory including computer program code. The at least one memory and computer program code are configured to, with the at least one processor, cause performance of the second apparatus.

In some example embodiments, the second apparatus comprises: means for transmitting, to a first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device, the message enabling the first device to determine a relaxed evaluation period for reference signal measurement, the first device being served by a serving cell provided by the second apparatus; and means for transmitting, to the first device, at least one reference signal.

In some example embodiments, the set of relaxation criteria comprises a first criterion related to a mobility of the first device, and a second criterion related to a serving cell quality for the first device.

In some example embodiments, the message enables the first device to determine the relaxed evaluation period by applying a scaling factor associated with the set of criteria to a basic evaluation period for the reference signal measurement, the first criterion corresponds to a first factor for scaling the basic evaluation period, the second criterion corresponds to a second factor for scaling the basic evaluation period, and the scaling factor comprises one of the first factor, the second factor, and a third factor. In an example embodiment, the third factor may correspond to both of the first criterion and the second criterion being met, and may be predefined/preconfigured or derived from the first factor and the second factor.

In some example embodiments, the first factor and the second factor are preconfigured at the first device and the second apparatus.

In some example embodiments, the second apparatus further comprises: means for transmitting, to the first device, a message for configuring a mapping relation between a combination of the relaxation criteria in the set and the first factor and the second factor.

example embodiments, the second apparatus further comprises: means for transmitting, to the first device, a message for enabling further relaxation of measurements when the set of relaxation criteria is fulfilled.

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

FIG. 7 is a simplified block diagram of a device 700 that is suitable for implementing embodiments of the present disclosure. The device 700 may be provided to implement the communication device, for example the terminal device 110 or the network device 120 as shown in FIG 1. As shown, the device 700 includes one or more processors 710, one or more memories 740 coupled to the processor 710, and one or more transmitters and/or receivers (TX/RX) 740 coupled to the processor 710.

The TX/RX 740 is for bidirectional communications. The TX/RX 740 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 710 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 700 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 720 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) 724, 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) 722 and other volatile memories that will not last in the power-down duration.

A computer program 730 includes computer executable instructions that are executed by the associated processor 710. The program 730 may be stored in the ROM 720. The processor 710 may perform any suitable actions and processing by loading the program 730 into the RAM 720.

The embodiments of the present disclosure may be implemented by means of the program 730 so that the device 700 may perform any process of the disclosure as discussed with reference to FIGs. 5-6. 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 730 may be tangibly contained in a computer readable medium which may be included in the device 700 (such as in the memory 720) or other storage devices that are accessible by the device 700. The device 700 may load the program 730 from the computer readable medium to the RAM 722 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. 8 shows an example of the computer readable medium 800 in form of CD or DVD. The computer readable medium has the program 730 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

method

500 or 600 as described above with reference to FIGs. 5 or 6. 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 providing at least a serving cell for the first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device;

measure at least one reference signal from the second device during a basic evaluation period for the reference signal measurement;

in accordance with a determination that the set of relaxation criteria is met based on a measurement result, determine a relaxed evaluation period based on the basic evaluation period and a scaling factor; and

perform the reference signal measurement for the at least one reference signal during the relaxed evaluation period.
The first device of Claim 1, wherein the set of relaxation criteria comprises a first criterion related to a mobility of the first device, and a second criterion related to a serving cell quality for the first device.
The first device of Claim 2, wherein the first criterion corresponds to a first factor for scaling the basic evaluation period, the second criterion corresponds to a second factor for scaling the basic evaluation period, and the scaling factor comprises one of the first factor, the second factor, and a third factor corresponding to both of the first criterion and the second criterion being met.
The first device of Claim 3, wherein the third factor comprises at least one of the following:

the maximum of the first factor and the second factor,

a sum of the first factor and the second factor, and

a product of the first factor and the second factor.
The first device of Claim 3, wherein the first factor and the second factor are preconfigured at the first device and the second device.
The first device of Claim 3, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, further cause the first device to:

receive, from the second device, a message for configuring a mapping relation between a combination of the relaxation criteria in the set and the first factor and the second factor.
The first device of Claim 2, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to determine the relaxed evaluation period by:

in accordance with a determination that the mobility of the first device is below a mobility threshold, determining that the first criterion is met;

in accordance with a determination that the serving cell quality for the first device exceeds a cell quality threshold, determining that the second criterion is met; and

determining the relaxed evaluation period by scaling the basic evaluation period with the scaling factor.
The first device of Claim 7, wherein the basic evaluation period is scaled with the scaling factor after the first criterion or/and the second criterion are met for a predetermined time period.
The first device of Claim 1, wherein the at least one reference signal is configured for one of radio link monitoring and beam failure detection, and at least one further reference signal is configured for the other one of the radio link monitoring and the beam failure detection, and wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to perform the reference signal measurement by:

performing one of the radio link monitoring and the beam failure detection on the at least one reference signal based on the relaxed evaluation period; and

refraining from performing the other one of the radio link monitoring and the beam failure detection on the at least one further reference signal.
The first device of Claim 9, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to perform the reference signal measurement by:

in accordance with a determination that the set of relaxation criteria is met on the one of the radio link monitoring and the beam failure detection for a predetermined time period, performing the reference signal measurement.
The first device of Claim 1, wherein the first device is configured for a plurality of reference signals, and wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to determine the relaxed evaluation period by:

in accordance with a determination that the set of criteria is met on the plurality of reference signals, determining the relaxed evaluation period based on the basic evaluation period and the scaling factor.
The first device of Claim 1, wherein the first device is configured for a plurality of reference signals, and wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to determine the relaxed evaluation period by:

in accordance with a determination that the set of criteria is met on a first subset of the plurality of reference signals, determining a first relaxed evaluation period based on the basic evaluation period and the scaling factor.
The first device of Claim 12, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, cause the first device to perform the reference signal measurement by:

performing the reference signal measurement on the first subset of the plurality of reference signals during the first relaxed evaluation period.
The first device of Claim 12, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, further cause the first device to:

in accordance with a determination that one of the set of criteria is met on a second subset of the plurality of reference signals, refrain from performing the reference signal measurement on the second subset of the plurality of reference signals.
The first device of Claim 12, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, further cause the first device to determine the relaxed evaluation period by:

in accordance with a determination that one of the set of criteria is met on a second subset of the plurality of reference signals, determining a second relaxed evaluation period by scaling the basic evaluation period based on one of the first factor and the second factor; and

performing the reference signal measurement on the second subset of the plurality of reference signals during the second relaxed evaluation period.
The first device of Claim 1, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, further cause the first device to:

receive, from the second device, a message for enabling further relaxation of measurements when the set of relaxation criteria is fulfilled.
The first device of Claim 1, wherein the reference signal measurement is associated with at least one of radio link monitoring and beam failure detection.
The first 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 indicating a set of relaxation criteria related to reference signal measurement for the first device, the message enabling the first device to determine a relaxed evaluation period for reference signal measurement, the second device providing at least a serving cell for the first device; and

transmit, to the first device, at least one reference signal.
The second device of Claim 19, wherein the set of relaxation criteria comprises a first criterion related to a mobility of the first device, and a second criterion related to a serving cell quality for the first device.
The second device of Claim 20, wherein the first message enables the first device to determine the relaxed evaluation period by applying a scaling factor associated with the set of criteria to a basic evaluation period for the reference signal measurement, the first criterion corresponds to a first factor for scaling the basic evaluation period, the second criterion corresponds to a second factor for scaling the basic evaluation period, and the scaling factor comprises one of the first factor, the second factor, and a third factor corresponding to both of the first criterion and the second criterion being met.
The second device of Claim 21, wherein the first factor and the second factor are preconfigured at the first device and the second device.
The second device of Claim 21, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, further cause the second device to:

transmit, to the first device, a message for configuring a mapping relation between a combination of the relaxation criteria in the set and the first factor and the second factor.
The second device of Claim 19, wherein the at least one memory and the computer program codes are configured to, with the at least one processor, further cause the second device to:

transmit, to the first device, a message for enabling further relaxation of measurements when the set of relaxation criteria is fulfilled.
The second device of Claim 19, wherein the reference signal measurement is associated with at least one of radio link monitoring and beam failure detection.
The second device of Claim 19, wherein the first device comprises a terminal device, and the second device comprises a network device.
A method comprising:

receiving, at a first device and from a second device providing at least a serving cell for the first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device;

measuring at least one reference signal from the second device during a basic evaluation period for the reference signal measurement;

in accordance with a determination that the set of relaxation criteria is met based on a measurement result, determining a relaxed evaluation period based on the basic evaluation period and a scaling factor; and

performing the reference signal measurement for the at least one reference signal during the relaxed evaluation period.
A method comprising:

transmitting, at a second device and to a first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device, the message enabling the first device to determine a relaxed evaluation period for reference signal measurement, the second device providing at least a serving cell for the first device; and

transmitting, to the first device, at least one reference signal.
A first apparatus comprising:

means for receiving, from a second device providing at least a serving cell for the first apparatus, a message indicating a set of relaxation criteria related to reference signal measurement for the first apparatus;

means for measuring at least one reference signal from the second device during a basic evaluation period for the reference signal measurement;

means for in accordance with a determination that the set of relaxation criteria is met based on a measurement result, determining a relaxed evaluation period based on the basic evaluation period and a scaling factor; and

means for performing the reference signal measurement for the at least one reference signal during the relaxed evaluation period.
A second apparatus comprising:

means for transmitting, to a first device, a message indicating a set of relaxation criteria related to reference signal measurement for the first device, the message enabling the first device to determine a relaxed evaluation period for reference signal measurement, the second apparatus providing at least a serving cell for the first device; and

means for transmitting, to the first device, at least one reference signal.
A computer readable medium comprising program instructions for causing an apparatus to perform at least the method of Claim 27 or 28.