WO2024229782A1

WO2024229782A1 - Rlm or bfd relaxation state reporting

Info

Publication number: WO2024229782A1
Application number: PCT/CN2023/093410
Authority: WO
Inventors: Jussi-Pekka Koskinen; Samuli Heikki TURTINEN; Chunli Wu
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2023-05-11
Filing date: 2023-05-11
Publication date: 2024-11-14
Anticipated expiration: 2025-11-11
Also published as: CN121058278A

Abstract

Example embodiments of the present disclosure relate to a terminal device, a network device, methods, apparatuses and a computer readable storage medium for RLM/BFD relaxation state reporting. In some embodiments, a terminal device may change its RLM/BFD relaxation status if a criterion of a condition is fulfilled. The terminal device may further transmit an indication associated with the condition to a network device to, so that the network device may be aware of the reason why the terminal device changes its RLM/BFD relaxation status. Accordingly, the network device may know why the terminal device is relaxing RLM/BFD measurements or why the terminal device is not relaxing RLM/BFD measurements.

Description

RLM OR BFD RELAXATION STATE REPORTING

FIELD

Example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to a terminal device, a network device, methods, apparatuses and a computer readable storage medium for radio link monitoring (RLM) or beam failure detection (BFD) relaxation state reporting.

BACKGROUND

The third generation partnership project (3GPP) has introduced the RLM/BFD relaxation in release 17 (Rel-17) . A terminal device, such as user equipment (UE) , may perform the RLM/BFD relaxation. Power saving may be achieved at the UE by relaxing measurements for RLM/BFD.

The current specification has defined that the UE is no longer allowed to relax RLM/BFD measurements if no discontinuous reception (DRX) is used or DRX cycle is longer than 80 ms. In case the UE is not allowed to relax anymore, the report of the relaxation status may be terminated or may include false information.

SUMMARY

In general, example embodiments of the present disclosure provide a solution for RLM/BFD relaxation state reporting.

In a first aspect, there is provided a terminal device. The terminal device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to: based on a determination that a criterion of a condition is fulfilled, change a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and transmit, to a network device, an indication associated with the condition.

In a second aspect, there is provided a network device. The network device comprises at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to: receive, from a terminal device, an indication associated with a condition, the condition being used for determining whether to change a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and determine that a criterion of the condition has been fulfilled and the relaxation status of the RLM or the BFD has been changed based on the indication.

In a third aspect, there is provided a method performed by a terminal device. The method comprises: based on a determination that a criterion of a condition is fulfilled, changing, at a terminal device, a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and transmitting, to a network device, an indication associated with the condition.

In a fourth aspect, there is provided a method performed by a network device. The method comprises: receiving, at a network device from a terminal device, an indication associated with a condition, the condition being used for determining whether to change a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and determining that a criterion of the condition has been fulfilled and the relaxation status of the RLM or the BFD has been changed based on the indication.

In a fifth aspect, there is provided an apparatus. The apparatus comprises: means for based on a determination that a criterion of a condition is fulfilled, changing, at a terminal device, a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and means for transmitting, to a network device, an indication associated with the condition.

In a sixth aspect, there is provided an apparatus. The apparatus comprises: means for receiving, at a network device from a terminal device, an indication associated with a condition, the condition being used for determining whether to change a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and means for determining that a criterion of the condition has been fulfilled and the relaxation status of the RLM or the BFD has been changed based on the indication.

In a seventh aspect, there is provided a terminal device. The terminal device comprises: changing circuitry configured to based on a determination that a criterion of a condition is fulfilled, change a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and transmitting circuitry configured to transmit, to a network device, an indication associated with the condition.

In an eighth aspect, there is provided a network device. The network device comprises: receiving circuitry configured to receive, from a terminal device, an indication associated with a condition, the condition being used for determining whether to change a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and determining circuitry configured to determine that a criterion of the condition has been fulfilled and the relaxation status of the RLM or the BFD has been changed based on the indication.

In a ninth aspect, there is provided a non-transitory computer readable medium comprising program instructions for causing an apparatus to perform at least the method in the third or fourth aspect.

In a tenth aspect, there is provided a computer program comprising instructions, which, when executed by an apparatus, cause the apparatus at least to perform the method in the third or 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, in which:

FIG. 1 illustrates an example of a network environment in which some example embodiments of the present disclosure may be implemented;

FIG. 2 illustrates an example of a process flow in accordance with some example embodiments of the present disclosure;

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

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

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

FIG. 6 illustrates a block diagram of an example of a 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 elements.

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 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 one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. 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 herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or” , mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

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 Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , New Radio (NR) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications 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 fifth generation (5G) , the sixth generation (6G) 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 new radio (NR) NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , an 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 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 (loT) device, a machine type communication (MTC) 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. In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

In the present disclosure, the term “RLM/BFD” may refer to “RLM and BFD” , “RLM or BFD” , or “RLM and/or BFD” depending on the discussed scenario.

RLM/BFD relaxation was introduced in Rel-17. When configured, a UE determines whether it is in low mobility state and/or whether its serving cell radio link quality is better than a threshold. The UE is allowed to perform RLM/BFD relaxation when relaxed measurement criterion for low mobility and/or for good serving cell quality is met. If configured to do so, the UE shall trigger reporting of its RLM/BFD relaxation status through UE assistance information (UAI) , if the UE changes its respective RLM/BFD relaxation status while meeting the UE minimum requirements specified in the 3GPP specification. The configuration for low mobility and good serving cell quality criterion is provided through dedicated radio resource control (RRC) signalling. RLM/BFD relaxation may be enabled/disabled separately through RRC configuration. Additionally, RLM relaxation may be enabled/disabled on per Cell Group basis, while BFD relaxation may be enabled/disabled on per serving cell basis. The following text boxes describe some non-restrictive introduction information of RLM/BFD relaxation which can be used in some example embodiments of the present disclosure.

The current specification also defined that the UE is no longer allowed to relax RLM measurements and apply the relaxed radio link monitoring provided that at least one of the following conditions is met:

- The UE sends out-of sync indications to the higher layers.

- The timer T310 is running.

- No DRX is used or DRX cycle is longer than 80ms.

The current specification also defined that the UE is no longer allowed to relax BFD measurements and apply the relaxed link recovery procedures provided that at least one of the following conditions is met:

- The timer beamFailureDetectionTimer is running.

- No DRX is used or DRX cycle is longer than 80ms.

In other words, the UE is no longer allowed to relax RLM/BFD measurements if no DRX is used or DRX cycle is longer than 80 ms, while whether DRX is used may be determined based on, e.g., information shown in the following text box:

Since DRX timers can be started and stopped frequently during the connection, the UE may frequently change its relaxation status. If the UE reports its status change every time, the power consumption will be increased. In some cases, the UE may determine to report its status change due to low mobility or good serving cell quality, if the DRX state changes before the reporting, the UE may report false/old information to the network. Therefore, the reporting of RLM/BFD relaxation state needs to be further studied.

Example embodiments of the present disclosure provide a solution for RLM/BFD relaxation state reporting. In some embodiments, a terminal device may change its RLM/BFD relaxation status if a criterion of a condition is fulfilled. The terminal device may further transmit an indication associated with the condition to a network device to, so that the network device may be aware of the reason why the terminal device changes its RLM/BFD relaxation status. Principles and some example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

FIG. 1 illustrates an example of a network environment 100 in which some example embodiments of the present disclosure may be implemented. The environment 100, which may be a part of a communication network, comprises a terminal device 110 and a network device 120. The network environment 100 may also be called as a network system, a communication environment, a communication network, a communication system, or the like, the present disclosure does not limit this aspect.

The environment 100 may comprise any suitable number of devices and cells. In the environment 100, the network device 120 can provide services to the terminal device 110, and the network device 120 and the terminal device 110 may communicate data and control information with each other. In some embodiments, the network device 120 and the terminal device 110 may communicate with direct links/channels.

In the environment 100, a link from the network device 120 to the terminal device 110 is referred to as a downlink (DL) , while a link from the terminal device 110 to the network device 120 is referred to as an uplink (UL) . In downlink, the network device 120 is a transmitting (TX) device (or a transmitter) and the terminal device 110 is a receiving (RX) device (or a receiver) . In uplink, the terminal device 110 is a transmitting TX device (or a transmitter) and the network device 120 is a RX device (or a receiver) . It is to be understood that the network device 120 may provide one or more serving cells. In some embodiments, the network device 120 can provide multiple cells.

Communications in the network environment 100 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) , the fifth generation (1G) and the sixth generation (6G) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and/or any other technologies currently known or to be developed in the future.

It is to be understood that the numbers of devices (i.e., the terminal device 110 and the network device 120) and their connection relationships and types shown in FIG. 1 are only for the purpose of illustration without suggesting any limitation. For example, the environment 100 may include any suitable numbers of devices adapted for implementing embodiments of the present disclosure. For example, while FIG. 1 depicts the terminal device 110 as a mobile phone; the terminal device 110 may be any type of user equipment.

FIG. 2 illustrates an example of a process flow 200 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the process flow 200 will be described with reference to FIG. 1. The process flow 200 involves the terminal device 110 and the network device 120. It would be appreciated that although the process flow 200 has been described in the network environment 100 of FIG. 1, this process flow may be likewise applied to other communication scenarios.

The terminal device 110 determines 210 that a criterion of a condition for changing a RLM/BFD relaxation status is fulfilled. A criterion is fulfilled may also be referred to as the criterion is satisfied or met, the present disclosure does not limit this aspect.

The criterion of the condition may be configured by the network device 120. In addition or alternatively, the network device 120 may transmit, to the terminal device 110, a configuration indicating the criterion of the condition, e.g., the configuration may be carried in RRC signalling. On the other side of communication, the terminal device 110 may receive the configuration. Accordingly, the terminal device 110 may determine whether a criterion is fulfilled based on the configuration.

The terminal device 110 changes 220 its RLM/BFD relaxation status in response to the determination that the criterion of the condition is fulfilled.

For ease of description, the RLM/BFD relaxation status may be “relaxation” when the terminal device 110 is performing the RLM/BFD relaxation, i.e., is relaxing the RLM/BFD measurements. For ease of description, the RLM/BFD relaxation status may be “non-relaxation” when the terminal device 110 is not performing the RLM/BFD relaxation, i.e., is not relaxing the RLM/BFD measurements.

In some example embodiments, the criterion of the condition may comprise one or more of: a first criterion or a second criterion. In some examples, the first criterion may be associated with a status changing from non-relaxation to relaxation, while the second criterion may be associated with a status changing from relaxation to non-relaxation. In other words, a fulfillment of the first criterion may trigger the terminal device 110 to change its RLM/BFD relaxation status from non-relaxation to relaxation, while a fulfillment of the second criterion may trigger the terminal device 110 to change its RLM/BFD relaxation status from relaxation to non-relaxation.

In some embodiments, the terminal device 110 may determine whether the first criterion is fulfilled when the terminal device 110 is not relaxing the RLM/BFD measurements. In some examples, if the first criterion is fulfilled, then the terminal device 110 may change its RLM/BFD relaxation status, i.e., start relaxing the RLM/BFD measurements. In other words, in case the first criterion is fulfilled, the terminal device 110 may perform (start performing) the RLM/BFD relaxation.

In some embodiments, the terminal device 110 may determine whether the second criterion is fulfilled when the terminal device 110 is relaxing the RLM/BFD measurements. In some examples, if the second criterion is fulfilled, then the terminal device 110 may change its RLM/BFD relaxation status, i.e., stop relaxing the RLM/BFD measurements. In other words, in case the second criterion is fulfilled, the terminal device 110 may stop performing the RLM/BFD relaxation.

The first criterion may include one or more of: a relaxed measurement criterion for the terminal device with a low mobility in RRC connected state (RRC_CONNECTED) , a relaxed measurement criterion for good serving cell quality, or DRX is used and a DRX cycle is not longer than a predefined value. In some examples, the predefined value may be 80 ms. It is to be understood that the example of the predefined value is not limited in the present disclosure, for example, it may be another value, such as 60 ms, 120 ms, or the like.

In some examples, the terminal device 110 may determine its current measurement result, and determine whether a difference of a reference measurement result and the current measurement result is smaller than a first threshold. If the difference is smaller than the first threshold, then the mobility is low. For example, the current measurement result may be a layer 3 (L3) reference signal received power (RSRP) measurement, which may be represented as SS-RSRP. For example, the reference measurement result may be a reference L3 RSRP measurement, which may be represented as SS-RSRP_Ref. For example, the first threshold may be preconfigured by the network device 120 or may be predefined, which may be represented as S_{SearchDeltaP-Connected}.

For example, the relaxed measurement criterion for UE with low mobility in RRC_CONNECTED is fulfilled when: (SS-RSRP_Ref –SS-RSRP) < S_{SearchDeltaP-Connected}.

In some examples, the terminal device 110 may determine a downlink radio link quality of a serving cell, and further determines whether the downlink radio link quality is better than a second threshold. For example, the second threshold may be represented as Q_in+XdB, where Q_in is preconfigured or predefined threshold and X is an offset.

For example, the relaxed measurement criterion of good serving cell quality for RLM is fulfilled when the downlink radio link quality on the configured RLM-RS resource is evaluated to be better than the threshold Q_in+XdB. For example, the relaxed measurement criterion of good serving cell quality for BFD is fulfilled when the downlink radio link quality on the configured BFD-RS resource is evaluated to be better than the threshold Q_in+XdB.

The second criterion may include one or more of: a relaxed measurement criterion for the terminal device with a high mobility in an RRC connected state (RRC_CONNECTED) , a relaxed measurement criterion for bad serving cell quality, DRX is not used, or a DRX cycle is longer than a predefined value. In some embodiments, the second criterion is fulfilled may be regarded as the first criterion is not fulfilled.

In some example embodiments, the condition may comprise a mobility of the terminal device 110 and/or a quality of a serving cell of the terminal device 110. In some example embodiments, the condition may comprise the DRX state.

The terminal device 110 transmits 230 an indication 232 associated with the condition to the network device 120. In some examples, the indication 232 may be transmitted together with measurement relaxation state information, such as rlm-MeasRelaxationState and/or bfd-MeasRelaxationState. In some other examples, the indication 232 may be transmitted independently from (or separate from) the measurement relaxation state information, e.g., the indication 232 is transmitted in addition to rlm-MeasRelaxationState and/or bfd-MeasRelaxationState.

In some example embodiments, the indication 232 may be transmitted in a UAI. In other words, the terminal device 110 may report the indication 232 by using a UAI.

In some examples, the indication 232 may indicate information about the relaxation status. For example, the indication 232 may include information on relaxation. As a specific example, the information on relaxation may indicate “relaxation” or “non-relaxation” . Thus, the network device 120 can be aware of the new relaxation status.

In some example embodiments, the indication 232 may indicate a reason of the RLM/BFD relaxation status changing, in other words, the indication 232 may indicate why the terminal device 110 changes its RLM/BFD relaxation status.

In some examples, the indication 232 may indicate a DRX state if the criterion of the condition is related with the DRX. For example, the indication 232 may include a specific value to indicate “DRX state” . Since the network device 120 has knowledge of the DRX, it may know whether the terminal device 110 is changing to relaxation or changing to non-relaxation.

In some examples, the indication 232 may indicate a change of the condition. In some examples, the indication 232 may indicate a change in the fulfillment of the RLM/BFD relaxation criterion, such as the relaxed measurement criterion for low mobility, and/or relaxed measurement criterion for good serving cell quality. For example, the terminal device 110 may obtain a first L3 RSRP measurement before changing the RLM/BFD relaxation status, and determine a second L3 RSRP measurement after changing the RLM/BFD relaxation status, where the indication 232 may indicate a difference of the first L3 RSRP measurement and the second L3 RSRP measurement. For example, the terminal device 110 may obtain a first downlink radio link quality of the serving cell before changing the RLM/BFD relaxation status, and determine a second downlink radio link quality of the serving cell after changing the RLM/BFD relaxation status, where the indication 232 may indicate a difference of the first downlink radio link quality of the serving cell and the second downlink radio link quality of the serving cell.

In some examples, the indication 232 may indicate which criterion is fulfilled, and/or which criterion is not fulfilled anymore. For example, the indication 232 may indicate that the relaxed measurement criterion for UE with low mobility in RRC_CONNECTED is not fulfilled anymore. For example, the indication 232 may indicate that the relaxed measurement criterion of good serving cell quality is not fulfilled anymore.

In some example embodiments, the reporting of the indication 232 may be triggered by changing of the RLM/BFD relaxation status, or triggered by fulfillment of the criterion.

In addition or alternatively, the terminal device 110 may further start at least one prohibit timer.

In some example embodiments, there may be multiple prohibit timers associated with multiple conditions. The terminal device 110 may start a specific prohibit timer associated with the specific condition, depending on the fulfilled criterion. For example, if the relaxed measurement criterion for UE with low mobility in RRC_CONNECTED is fulfilled, a first prohibit timer associated with low mobility may be started. For example, if the relaxed measurement criterion of good serving cell quality is fulfilled, a second prohibit timer associated with good serving cell quality may be started. For example, if the criterion of DRX is used and DRX cycle is not longer than a predefined value is fulfilled, a third prohibit timer associated with DRX state may be started. It is to be understood that if more than one criterion is fulfilled, more than one prohibit timer may be started. If a further criterion is fulfilled and the associated prohibit timer is running, then the reporting may be terminated. For example, assume that the DRX state is changed and the RLM/BFD relaxation status is further changed, then there is no further indication transmitted by the terminal device 110 if the third prohibit timer is running. However, a running prohibit timer will not prevent a reporting associated with other conditions. For example, assume that the DRX state is changed and the RLM/BFD relaxation status is further changed, then there is a further indication transmitted by the terminal device 110 if the third prohibit timer is not running, even if the first prohibit timer and/or the second prohibit timer is running. In other words, the reporting associated with DRX state is transmitted regardless of the running first prohibit timer and/or second prohibit timer.

In some other example embodiments, a specific prohibit timer may be associated with more than one condition. In some examples, the first prohibit timer and the second prohibit timer may be implemented as a same prohibit timer.

In some examples, the first prohibit timer, the second prohibit timer, and the third prohibit timer may be implemented as a same prohibit timer, e.g., there is only one prohibit timer at the terminal device 110. For example, if the prohibit timer is running, there will be no reporting transmitted by the terminal device 110, regardless of the criterion. For example, during a time period that the prohibit timer is running, the terminal device 110 may determine that a criterion is fulfilled and its RLM/BFD relaxation status is changed, but no further indication will be transmitted to the network device 120. As such, overhead may be reduced and the power saving may be guaranteed.

On the other side of communication, the network device 120 receives 234 the indication 232. Accordingly, the network device 120 determines 240 that a criterion of the condition has been fulfilled and the RLM/BFD relaxation status has been changed.

In some example embodiments, the network device 120 may determine the RLM/BFD relaxation statues of the terminal device 110 based on the indication 232. In some example embodiments, the network device 120 may determine the reason of changing the RLM/BFD relaxation statues (why the RLM/BFD relaxation statues is changed) based on the indication 232.

As such, the network device 120 can know the reason why the terminal device 110 is relaxing RLM/BFD measurements, or the reason why the terminal device 110 is not relaxing RLM/BFD measurements.

As a specific example, the indication 232 may indicate DRX state. Since the network device 120 has knowledge of DRX, for example, no DRX is used, then the network device 120 may determine that the terminal device 110 is not relaxing RLM/BFD measurements because no DRX is used.

According to the embodiments with reference to FIG. 2, a solution for RLM/BFD relaxation state reporting is proposed. In some embodiments, a terminal device may change its RLM/BFD relaxation status if a criterion of a condition is fulfilled. The terminal device may further transmit an indication associated with the condition to a network device, so that the network device may be aware of the reason why the terminal device changes its RLM/BFD relaxation status. Accordingly, the network device may know why the terminal device is relaxing RLM/BFD measurements or why the terminal device is not relaxing RLM/BFD measurements.

FIG. 3 illustrates a flowchart of a method 300 implemented at a terminal device in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 300 will be described from the perspective of the terminal device 110 with reference to FIG. 1.

At block 310, if a criterion of a condition is fulfilled, the terminal device 110 changes a relaxation status of RLM or BFD. At block 320, the terminal device 110 transmits, to a network device, an indication associated with the condition.

In some example embodiments, the criterion of the condition comprises at least one of: a relaxed measurement criterion for the terminal device with a low mobility in RRC connected state, a relaxed measurement criterion for good serving cell quality, or DRX is used and a DRX cycle is not longer than a predefined value.

In some example embodiments, the relaxed measurement criterion for the terminal device with a low mobility in the RRC connected state comprises: a difference of a reference L3 RSRP measurement and a current L3 RSRP measurement is less than a first threshold.

In some example embodiments, the relaxed measurement criterion for good serving cell quality comprises: a downlink radio link quality of the serving cell is better than a second threshold.

In some example embodiments, the terminal device 110 performs at least one of an RLM relaxation or a BFD relaxation.

In some example embodiments, the criterion of the condition comprises at least one of: a relaxed measurement criterion for the terminal device with a high mobility in an RRC connected state, a relaxed measurement criterion for bad serving cell quality, DRX is not used, or a DRX cycle is longer than a predefined value.

In some example embodiments, the terminal device 110 stops performing at least one of an RLM relaxation or a BFD relaxation.

In some example embodiments, the indication indicates at least one of: information about the relaxation status, a DRX state, or a change of the condition.

In some example embodiments, the indication is transmitted in UAI. In some example embodiments, the indication is transmitted together with or separate from measurement relaxation state information.

In some example embodiments, the terminal device 110 starts a prohibit timer associated with the condition.

In some example embodiments, if the prohibit timer associated with the condition is running, the terminal device 110 stops transmitting a further indication after a further change of the relaxation status.

In some example embodiments, if a further criterion of a further condition is fulfilled, the terminal device 110 further changes the relaxation status. In some example embodiments, the terminal device 110 transmits, to the network device, a further indication associated with the further condition, and starts a further prohibit timer associated with the further condition.

FIG. 4 illustrates a flowchart of a method 400 implemented at a network device in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 400 will be described from the perspective of the network device 120 with reference to FIG. 1.

At block 410, the network device 120 receives, from a terminal device, an indication associated with a condition, the condition being used for determining whether to change a relaxation status of RLM or BFD. At block 420, the network device 120 determines that a criterion of the condition has been fulfilled and the relaxation status of the RLM or the BFD has been changed based on the indication.

In some example embodiments, the network device 120 determines that the terminal device has performed at least one of an RLM relaxation or a BFD relaxation.

In some example embodiments, the network device 120 determines that the terminal device has stopped performing at least one of an RLM relaxation or a BFD relaxation.

In some example embodiments, the network device 120 starts a prohibit timer associated with the condition.

In some example embodiments, if the prohibit timer associated with the condition is running, the network device 120 stops monitoring a further indication associated with any condition.

In some example embodiments, the network device 120 receives, from the terminal device, a further indication associated with a further condition; the network device 120 determines that a further criterion of the further condition has been fulfilled and the relaxation status of the RLM or the BFD has been further changed based on the further indication; and the network device 120 starts a further prohibit timer associated with the further condition.

In some example embodiments, an apparatus capable of performing the method 300 (for example, 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 based on a determination that a criterion of a condition is fulfilled, changing a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and means for transmitting, to a network device, an indication associated with the condition.

In some example embodiments, the apparatus comprises: means for performing at least one of an RLM relaxation or a BFD relaxation.

In some example embodiments, the apparatus comprises: means for stopping performing at least one of an RLM relaxation or a BFD relaxation.

In some example embodiments, the apparatus comprises: means for starting a prohibit timer associated with the condition.

In some example embodiments, the apparatus comprises: means for based on a determination that the prohibit timer associated with the condition is running, stopping transmitting a further indication after a further change of the relaxation status.

In some example embodiments, the apparatus comprises: means for based on a determination that a further criterion of a further condition is fulfilled, further changing the relaxation status; and means for transmitting, to the network device, a further indication associated with the further condition; and means for starting a further prohibit timer associated with the further condition.

In some example embodiments, an apparatus capable of performing the method 400 (for example, the network device 120 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 receiving, from a terminal device, an indication associated with a condition, the condition being used for determining whether to change a relaxation status of RLM or BFD; and means for determining that a criterion of the condition has been fulfilled and the relaxation status of the RLM or the BFD has been changed based on the indication.

In some example embodiments, the apparatus comprises: means for determining that the terminal device has performed at least one of an RLM relaxation or a BFD relaxation.

In some example embodiments, the apparatus comprises: means for determining that the terminal device has stopped performing at least one of an RLM relaxation or a BFD relaxation.

In some example embodiments, the apparatus comprises: means for based on a determination that the prohibit timer associated with the condition is running, stopping monitoring a further indication associated with any condition.

In some example embodiments, the apparatus comprises: means for receiving, from the terminal device, a further indication associated with a further condition; means for determining that a further criterion of the further condition has been fulfilled and the relaxation status of the RLM or the BFD has been further changed based on the further indication; and means for starting a further prohibit timer associated with the further condition.

FIG. 5 illustrates a simplified block diagram of a device 500 that is suitable for implementing some example embodiments of the present disclosure. The device 500 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 500 includes one or more processors 510, one or more memories 520 coupled to the processor 510, and one or more communication modules 540 coupled to the processor 510.

The communication module 540 is for bidirectional communications. The communication module 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 524. The processor 510 may perform any suitable actions and processing by loading the program 530 into the RAM 522.

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 example 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. 6 illustrates a block diagram of an example of a computer readable medium 600 in accordance with some example embodiments of the present disclosure. The computer readable medium 600 has the program 530 stored thereon. It is noted that although the computer readable medium 600 is depicted in form of CD or DVD in FIG. 6, the computer readable medium 600 may be in any other form suitable for carry or hold the program 530.

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, apparatus, 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 as described above with reference to any of 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 apparatus, 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, apparatus 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, apparatus, 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. The term “non-transitory, ” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM) .

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 terminal device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to:

based on a determination that a criterion of a condition is fulfilled, change a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and

transmit, to a network device, an indication associated with the condition.
The terminal device of claim 1, wherein the criterion of the condition comprises at least one of:

a relaxed measurement criterion for the terminal device with a low mobility in a radio resource control (RRC) connected state,

a relaxed measurement criterion for good serving cell quality, or

discontinuous reception (DRX) is used and a DRX cycle is not longer than a predefined value.
The terminal device of claim 2, wherein the relaxed measurement criterion for the terminal device with a low mobility in the RRC connected state comprises:

a difference of a reference layer 3 (L3) reference signal received power (RSRP) measurement and a current L3 RSRP measurement is less than a first threshold.
The terminal device of claim 2, wherein the relaxed measurement criterion for good serving cell quality comprises:

a downlink radio link quality of the serving cell is better than a second threshold.
The terminal device of any of claims 2-4, wherein the terminal device is caused to change the relaxation status by:

performing at least one of an RLM relaxation or a BFD relaxation.
The terminal device of claim 1, wherein the criterion of the condition comprises at least one of:

a relaxed measurement criterion for the terminal device with a high mobility in an RRC connected state,

a relaxed measurement criterion for bad serving cell quality,

DRX is not used, or

a DRX cycle is longer than a predefined value.
The terminal device of claim 6, wherein the terminal device is caused to change the relaxation status by:

stopping performing at least one of an RLM relaxation or a BFD relaxation.
The terminal device of any of claims 1-7, wherein the indication indicates at least one of:

information about the relaxation status,

a DRX state, or

a change of the condition.
The terminal device of any of claims 1-8, wherein the indication is transmitted in user equipment (UE) assistance information (UAI) .
The terminal device of any of claims 1-9, wherein the indication is transmitted together with measurement relaxation state information.
The terminal device of any of claims 1-10, wherein the terminal device is further caused to:

start a prohibit timer associated with the condition.
The terminal device of claim 11, wherein the terminal device is further caused to:

based on a determination that the prohibit timer associated with the condition is running, stop transmitting a further indication after a further change of the relaxation status.
The terminal device of claim 11, wherein the terminal device is further caused to:

based on a determination that a further criterion of a further condition is fulfilled, further change the relaxation status; and

transmit, to the network device, a further indication associated with the further condition; and

start a further prohibit timer associated with the further condition.
A network device comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to:

receive, from a terminal device, an indication associated with a condition, the condition being used for determining whether to change a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and

determine that a criterion of the condition has been fulfilled and the relaxation status of the RLM or the BFD has been changed based on the indication.
The network device of claim 14, wherein the criterion of the condition comprises at least one of:

a relaxed measurement criterion for the terminal device with a low mobility in a radio resource control (RRC) connected state,

a relaxed measurement criterion for good serving cell quality, or

discontinuous reception (DRX) is used and a DRX cycle is not longer than a predefined value.
The network device of claim 15, wherein the relaxed measurement criterion for the terminal device with a low mobility in the RRC connected state comprises:

a difference of a reference layer 3 (L3) reference signal received power (RSRP) measurement and a current L3 RSRP measurement is less than a first threshold.
The network device of claim 15, wherein the relaxed measurement criterion for good serving cell quality comprises:

a downlink radio link quality of the serving cell is better than a second threshold.
The network device of any of claims 15-17, wherein the network device is caused to:

determine that the terminal device has performed at least one of an RLM relaxation or a BFD relaxation.
The network device of claim 14, wherein the criterion of the condition comprises at least one of:

a relaxed measurement criterion for the terminal device with a high mobility in an RRC connected state,

a relaxed measurement criterion for bad serving cell quality,

DRX is not used, or

a DRX cycle is longer than a predefined value.
The network device of claim 19, wherein the network device is caused to:

determine that the terminal device has stopped performing at least one of an RLM relaxation or a BFD relaxation.
The network device of any of claims 14-20, wherein the indication indicates at least one of:

information about the relaxation status,

a DRX state, or

a change of the condition.
The network device of any of claims 14-21, wherein the indication is transmitted in user equipment (UE) assistance information (UAI) .
The network device of any of claims 14-22, wherein the indication is transmitted together with measurement relaxation state information.
The network device of any of claims 14-23, wherein the network device is further caused to:

start a prohibit timer associated with the condition.
The network device of claim 24, wherein the network device is further caused to:

based on a determination that the prohibit timer associated with the condition is running, stop monitoring a further indication associated with any condition.
The network device of claim 24, wherein the network device is further caused to:

receive, from the terminal device, a further indication associated with a further condition;

determine that a further criterion of the further condition has been fulfilled and the relaxation status of the RLM or the BFD has been further changed based on the further indication; and

start a further prohibit timer associated with the further condition.
A method comprising:

based on a determination that a criterion of a condition is fulfilled, changing, at a terminal device, a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and

transmitting, to a network device, an indication associated with the condition.
A method comprising:

receiving, at a network device from a terminal device, an indication associated with a condition, the condition being used for determining whether to change a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and

determining that a criterion of the condition has been fulfilled and the relaxation status of the RLM or the BFD has been changed based on the indication.
An apparatus comprising:

means for based on a determination that a criterion of a condition is fulfilled, changing, at a terminal device, a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and

means for transmitting, to a network device, an indication associated with the condition.
An apparatus comprising:

means for receiving, at a network device from a terminal device, an indication associated with a condition, the condition being used for determining whether to change a relaxation status of a radio link monitoring (RLM) or a beam failure detection (BFD) ; and

means for determining that a criterion of the condition has been fulfilled and the relaxation status of the RLM or the BFD has been changed based on the indication.
A computer readable medium comprising program instructions for causing an apparatus to perform at least the method of any of claims 27-28.