WO2023065261A1

WO2023065261A1 - Devices, methods and computer readable media for reducing sounding reference signal switching interruptions

Info

Publication number: WO2023065261A1
Application number: PCT/CN2021/125477
Authority: WO
Inventors: Lei Du; Lars Dalsgaard
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: 2021-10-22
Filing date: 2021-10-22
Publication date: 2023-04-27
Anticipated expiration: 2024-04-22
Also published as: CN118140514A; EP4393189A4; EP4393189A1

Abstract

Disclosed are methods and apparatus for reducing sounding reference signal switching interruptions. A terminal device in a communication network may comprise at least one processor and at least one memory having computer program code stored thereon and configured, with the at least one processor, cause the terminal device to perform: receiving, from a network device, one or more relaxation criteria for RLM and/or beam failure detection for performing relaxed measurements for RLM and/or beam failure detection; performing relaxed measurements for RLM and/or BFD when the one or more relaxation criteria for RLM and/or BFD are fulfilled for performing the relaxed measurements for RLM and/or BFD; and performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for RLM and/or BFD when the one or more relaxation criteria for RLM and/or BFD are fulfilled for performing the relaxed measurements for RLM and/or BFD.

Description

DEVICES, METHODS AND COMPUTER READABLE MEDIA FOR REDUCING SOUNDING REFERENCE SIGNAL SWITCHING INTERRUPTIONS

TECHNICAL FIELD

Various example embodiments described herein generally relate to communication technologies, and more particularly, to devices, methods, and computer readable media for reducing sounding reference signal (SRS) switching interruptions caused by relaxed radio link Monitoring (RLM) and/or beam failure detection (BFD) measurements.

BACKGROUND

In 5G New Radio, a sounding reference signal (RS) may be used to estimate uplink (UL) and downlink (DL) channel quality. Transmitting the RS with the correct power is essential for channel sounding. The user equipment (UE) can perform relaxed radio link Monitoring and/or beam failure detection under certain conditions so that the UE power can be saved. The SRS switching, including SRS carrier based switching and SRS antenna switching, may be impacted by such measurements when SRS switching is colliding with the measurements for radio link monitoring and/or beam failure detection. Normally, it was agreed to prioritize measurements for radio link monitoring and/or beam failure detection over SRS switching if measurements for radio link monitoring and/or beam failure detection are colliding with SRS switching as measurement for radio link monitoring and/or beam failure detection is considered more important than SRS carrier based switching or SRS antenna port switching. In the case where the UE needs to save power, the UE is allowed to perform relaxed measurements for radio link monitoring and/or beam failure detection when certain conditions are fulfilled. It is not determined, however, how the SRS switching and the relaxed RLM or BFD measurements can work together with UE’s need for power saving. An improved SRS transmission skipping scheme is needed which accounts both the UE’s need for skipping SRS transmissions when SRS transmissions overlap with RS used for RLM or BFD, and the UE’s need for relax measurements for RLM or BFD.

SUMMARY

A brief summary of exemplary embodiments is provided below to provide basic understanding of some aspects of various embodiments. It should be noted that this summary is not intended to identify key features of essential elements or define scopes of the embodiments, and its sole purpose is to introduce some concepts in a simplified form as a preamble for a more detailed description provided below.

In a first aspect, an example embodiment of a terminal device in a communication network is provided. The terminal device may comprise at least one processor and at least one memory. At least one memory includes computer program code stored thereon. At least one memory and the computer program code may be configured to, with at least one processor, cause the terminal device to perform: receiving, from a network device, one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection; performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection; and performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to perform: transmitting, to a network device, a message indicative of support of performing the sounding reference signal switching with reduced interruptions when performing the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection comprises: refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the sounding reference signal switching.

In some embodiments, refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the sounding reference signal switching comprises: refraining from performing the measurements for radio link monitoring and/or beam failure detection to ensure the terminal device is able to evaluate the downlink radio link quality within a certain time period.

In some embodiments, the certain time period refers to the minimum evaluation period over which the terminal device shall be able to evaluate the downlink radio link quality based on the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to perform: receiving, from the network device, a sounding reference signal switching configuration before transmitting, to a network device, the message.

In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to perform: determining which of the sounding reference signal switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection to obtain surviving sounding reference signal switching; and refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the surviving sounding reference signal switching.

In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to perform: transmitting, to the network device, information on which of the sounding reference signal switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the information is transmitted with the message.

In some embodiments, the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises at least low mobility of the terminal device, good serving cell quality, and/or DRX cycle condition.

In some embodiments, the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises dedicated indication from network to enable the terminal device to perform relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the sounding reference signal switching comprises sounding reference signal antenna switching and/or sounding reference signal carrier based switching.

In some embodiments, the sounding reference signal switching comprises the time to transmit sounding reference signal, and/or the time for switching the antenna or carrier.

In a second aspect, an example embodiment of a network device in a communication network is provided. The network device may comprise at least one processor and at least one memory.

At least one memory includes computer program code stored thereon. At least one memory and the computer program code may be configured to, with at least one processor, cause the network device to perform: transmitting, to a terminal device, one or more relaxation criteria for radio link monitoring beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection. The terminal device performs sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the antenna port correspondence indicates full correspondence in a case where the antenna ports used for reception of DL RS resources are the same antenna ports as being used for the transmission of UL RS resources at the terminal device.

In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network device to perform: receiving, from the terminal device, a message indicative of support of performing the sounding reference signal switching with reduced interruptions when relaxed measurements for radio link monitoring and/or beam failure detection are performed by the terminal device.

In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network device to perform: transmitting, to the terminal device, a sounding reference signal switching configuration before receiving the message from the terminal device.

In some embodiments, the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network device to perform: receiving, from the terminal device, information on which of the SRAS switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the information is received with the message.

In some embodiments, the sounding reference signal switching the sounding reference signal switching comprises the time to transmit sounding reference signal, and/or the time for switching the antenna or carrier.

In a third aspect, an example embodiment of a method implemented at a terminal device in a communication network is provided. The method may comprise: receiving, from a network device, one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection; performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection; and performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the method further comprises: transmitting, to a network device, a message indicative of support of performing the sounding reference signal switching with reduced interruptions when performing the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the method further comprises: receiving, from the network device, a sounding reference signal switching configuration before transmitting, to a network device, the message.

In some embodiments, performing sounding reference signal switching with reduced interruptions caused by performing measurements for radio link monitoring and/or beam failure detection comprises: determining which of the sounding reference signal switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection to obtain surviving sounding reference signal switching; and refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the surviving sounding reference signal switching.

In some embodiments, the method further comprises: transmitting, to the network device, information on which of the sounding reference signal switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the information is transmitted with the message.

In a fourth aspect, an example embodiment of a method implemented at a network device in a communication network is provided. The method may comprise transmitting, to a terminal device, one or more relaxation criteria for radio link monitoring beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection, wherein the terminal device performs sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the method further comprises: receiving, from the terminal device, a message indicative of support of performing the sounding reference signal switching with reduced interruptions when relaxed measurements for radio link monitoring and/or beam failure detection are performed by the terminal device.

In some embodiments, the method further comprises: transmitting, to the terminal device, a sounding reference signal switching configuration before receiving the message from the terminal device.

In some embodiments, the method further comprises: receiving, from the terminal device, information on which of the SRAS switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection.

In some embodiments, the information is received with the message.

In a fifth aspect, an example embodiment of an apparatus in a communication network is provided. Apparatus may comprise means for receiving, from a network device, one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection; means for performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection; and means for performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

In a sixth aspect, an example embodiment of an apparatus in a communication network is provided. Apparatus may comprise means for transmitting, to a terminal device, one or more relaxation criteria for radio link monitoring beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection. The terminal device performs sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

In a seventh aspect, an example embodiment of a computer program is provided. The computer program may comprise instructions stored on a computer readable medium. The instructions may, when executed by at least one processor of a terminal device in a communication network, cause the terminal device to perform: receiving, from a network device, one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection; performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection; and performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

In an eighth aspect, an example embodiment of a computer program is provided. The computer program may comprise instructions stored on a computer readable medium. The instructions may, when executed by at least one processor of a network device in a communication network, cause the network device to perform: transmitting, to a terminal device, one or more relaxation criteria for radio link monitoring beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection. The terminal device performs sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

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

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described, by way of non-limiting examples, with reference to accompanying drawings.

FIG. 1 is a schematic diagram illustrating a communication system 100 in which example embodiments of the present application can be implemented.

FIG. 2 shows an exemplary sequence diagram for reducing sounding reference signal switching interruptions according to an embodiment of the present disclosure.

FIG. 3 shows an exemplary scenario, where SRS switching interruptions are reduced when performing relaxed measurements for RLM.

FIG. 4 shows a block diagram illustrating an example communication network 400 for reducing sounding reference signal switching interruptions in which example embodiments of the present disclosure can be implemented.

FIG. 5 shows a flow chart illustrating an example method 500 for reducing sounding reference signal switching interruptions according to an embodiment of the present disclosure.

FIG. 6 shows a flow chart illustrating an example method 600 for reducing sounding reference signal switching interruptions according to an embodiment of the present disclosure.

FIG. 7 shows a block diagram illustrating an example apparatus 700 for reducing sounding reference signal switching interruptions according to an embodiment of the present disclosure.

FIG. 8 shows a block diagram illustrating an example apparatus 800 for reducing sounding reference signal switching interruptions according to an embodiment of the present disclosure.

Throughout the drawings, same or similar reference numbers indicate same or similar elements. A repetitive description on the same elements would be omitted.

DETAILED DESCRIPTION

Herein below, some example embodiments are described in detail with reference to accompanying drawings. The following description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in art that these concepts may be practiced without these specific details. In some instances, well known circuits, techniques and components are shown in block diagram form to avoid obscuring the described concepts and features.

As used herein, the term "network device" refers to any suitable entities or devices that can provide cells or coverage, through which the terminal device can access the network or receive services. The network device may be commonly referred to as a base station. The term "base station" used herein can represent a node B (NodeB or NB) , an evolved node B (eNodeB or eNB) , or a gNB or an ng-eNB. The base station may be embodied as a macro base station, a relay node, or a low power node such as a pico base station or a femto base station. The base station may consist of several distributed network units, such as a central unit (CU) , one or more distributed units (DUs) , one or more remote radio heads (RRHs) or remote radio units (RRUs) . The number and functions of these distributed units depend on the selected split RAN architecture.

As used herein, the term "terminal device" or "user equipment" (UE) refers to any entities or devices that can wirelessly communicate with the network devices or with each other. Examples of the terminal device can include a mobile phone, a mobile terminal, a mobile station, a subscriber station, a portable subscriber station, an access terminal, a computer, a wearable device, an on-vehicle communication device, a machine type communication (MTC) device, an internet of things (IoT) device, an internet of everything (IoE) device, a device-to-device (D2D) communication device, a vehicle to everything (V2X) communication device, a sensor and the like. The term "terminal device" can be used interchangeably with UE, a user terminal, a mobile terminal, a mobile station, or a wireless device.

FIG. 1 illustrates a schematic diagram of a communication system 100 in which example embodiments of the present disclosure can be implemented. Referring to FIG. 1, the communication system 100 may include a user equipment (UE) device 110 and a network device 120. The UE device 110 may communicate with the network device 120 on uplink (UL) and downlink (DL) channels. The UE device 110 and the network device 120 may be a part of a cellular communication network, such as a 5G NR network, in which the UE device 110 may be implemented as an NR-enabled UE device 110, and the network device 120 may be implemented as a next Generation Node-B (gNB) . It would be appreciated that the NR network may comprise more than one UE devices 110 and/or more than one network devices 120. The UE device 110 may wirelessly communicate with the network device 120 on uplink (UL) and downlink (DL) channels. Although not shown, the network device120 may also connect to other base stations via wireless or wired connections. The network device 120 provides access to the network for the UE device 110.

FIG. 2 shows an exemplary sequence diagram for reducing sounding reference signal switching interruptions according to an embodiment of the present disclosure. Referring to the FIG. 2, the UE device 110 may be a terminal device having multiple antenna ports associated with different communication channels, and channel quality for one antenna port may be different from channel quality for another antenna port. The UE device 110 may be configured to transmit reference signals, such as sounding reference signals with SRS switching, on RS resources to the network device 120, and the number of the RSs and/or the RS resources may be determined based on the number of antenna ports or the number of carriers. The network device 120 may be a device on the network side. The network device 120 may receive reference signals, such as sounding reference signals, on RS resources from the UE device 110, and the network device 120 may measure the channel quality based on the received RSs.

In an operation 210, the UE device 110 may receive, from the network device 120, one or more relaxation criteria for radio link monitoring (RLM) and/or beam failure detection (BFD) for performing relaxed measurements for radio link monitoring and/or beam failure detection. On the other hand, the network device 120 may transmit to the UE device 110 one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection.

In one embodiment, the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises at least one or more of the following: low mobility of the terminal device, good serving cell quality, and/or DRX cycle condition. For example, the network device 120 may configure one or more thresholds to the UE device 110 for determining the low mobility state. If the UE detects the reference signal received power (RSRP) variation within a certain time period exceeds the configured threshold, it determines the low mobility criteria is fulfilled and may start relaxed RLM and/or BFD measurements. Similarly, the network device 120 may configure one or more thresholds to the UE device 110 for determining the good serving cell quality state. If the UE device 110 evaluates the downlink radio link quality exceeds the configured threshold, it determines the good serving cell quality criteria is fulfilled and may start relaxed RLM and/or BFD measurements. As for DRX cycle condition, network may configure the DRX parameters to the UE. The UE device 110 may determine to relax RLM and/or BFD measurements only if the DRX cycle is shorter or no more than a certain pre-defined value. It is noted these relaxation criteria may be configured by the network device 120 as stated above, or the relevant relaxation parameters e.g. thresholds may be pre-defined and well understood between the network and the UE device 110. In the latter case, the network device 120 may not configure any relaxation parameters, but just indicate the criteria with pre-defined parameters needs to be considered when determining to relax the RLM and/or BFD measurements.

In another embodiment, the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises dedicated indication from network device 120 to enable the UE device 110 to perform relaxed measurements for radio link monitoring and/or beam failure detection. For example, the network device 120 may send an explicit indication to the UE device 110 when the network device 120 evaluates and determines the UE device 110 can start relaxed RLM and/or BFD measurements. Upon receiving the indication, the UE device 110 may assume one or more relaxation criteria is fulfilled and can start relaxed RLM and/or BFD measurements immediately. When the UE device 110 operates in the relaxed measurement mode, it may perform fewer measurements on radio resources in time and/or frequency and/or space than in non-relaxed or less relaxed measurement mode. In the relaxed measurement mode, the UE device 110 may skip at least one measurement on a radio resource that it would perform in non-relaxed or less relaxed measurement mode. Alternatively or additionally, in the relaxed measurement mode, the UE device 110 may increase distances between radio resources on which measurements are performed.

In one embodiment, the sounding reference signal switching comprises sounding reference signal antenna switching and/or sounding reference signal carrier based switching. Taking SRS carrier based switching as example, SRS transmission can be configured on a carrier not configured for PUCCH/PUSCH transmission. When a UE device 110 needs to transmit periodic, semi-persistent or aperiodic SRS on a carrier of a serving cell not configured for PUCCH/PUSCH transmission, the UE device 110 can perform carrier based switching to one or more carriers not configured for physical uplink control channel (PUCCH) or physical uplink shared channel (PUSCH) transmission from a carrier with PUCCH or PUSCH transmission or from a carrier not configured for PUCCH or PUSCH transmission prior to transmitting SRS, provided that the following conditions are met: switching is from a configured carrier to another activated carrier; the carrier of secondary cells (SCells) not configured for PUCCH/PUSCH transmission to which SRS carrier based switching is performed is indicated by DCI SRS request field for aperiodic SRS transmission, or indicated by MAC-CE for semi-persistent SRS transmission, or configured via RRC for periodic SRS transmission; the serving cell, from which SRS carrier based switching is performed and whose UL transmission may therefore be interrupted, is indicated by srs-SwitchFromServCellIndex and srs-SwitchFromCarrier in TS38.331; the SRS switching is not colliding with any other transmission with higher priority defined in TS 38.214 [26] ; the SRS switching is not colliding with any Synchronization Signal/PBCH block (SSB) /channel state information reference signal (CSI-RS) based L3 measurements and the measurements for RLM/BFD, and this does not apply if RLM/BFD relaxation measurements are configured and the UE indicates that it support txSwitchOmitRelaxedRLM in the capability (Option 1) ; the SRS switching is not colliding with any SSB/CSI-RS based L3 measurements and the measurements for RLM/BFD, if the UE has not indicated txSwitchOmitRelaxedRLM in the capability (Option 2) ; for UE, which does not support simultaneous reception and transmission for inter-band TDD CA specified in TS 38.331, and is compliant to the requirements for inter-band CA with uplink in one NR band and without simultaneous Rx/Tx specified in TS 38.101, and the SRS transmission are not simultaneously scheduled with DL SSB/CSI-RS for L3 or L1 measurements transmission on other carriers. The UE device 110 shall not perform SRS carrier based switching if the above conditions cannot be met.

In one embodiment, the sounding reference signal switching may comprise the time to transmit sounding reference signal, and/or the time for switching the antenna or carrier. For example, the sounding reference signal antenna port switching time period may include the SRS resources configured in SRS antenna port switching, the guard period between the consecutive SRS switching if there is any, and/or the transient period before and after the SRS transmission. In another example, the SRS carrier based switching time may include the SRS resources configured in SRS carrier based switching, and the RF retuning time between carriers. Alternatively, it may be equal to the interruption time at SRS switching.

In an operation 220, the network device 120 may perform relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

For example, when the above mentioned relaxation criteria are fulfilled, the UE device 110 can perform relaxed measurements for RLM or BFD to save power. Normally, the UE device 110 performs measurements for RLM/BFD on each of the configured RSs, and evaluates the DL channel quality based on a certain number of e.g. the latest 10 measurement samples within a certain time period, which is the legacy evaluation period. When one or more relaxation criteria are fulfilled, the UE device 110 is allowed to measure the configured RSs less often e.g. omitting some of the RSs to save power. For example, the UE device 110 can be allowed to only measure some of the available configured RSs, such as one RS every two consecutively configured RSs.

This enables the UE device 110 to save power by allowing the UE device 110 to perform less often RLM/BFD measurements compared to when not allowed to perform relaxed RLM/BFD measurements. For example, the UE device 110 can measure less samples, such as 5 samples during a certain time period, but in order to ensure the measurement performance the UE device 110 may use a longer or extended evaluation period to receive the same number of measurement samples as in legacy measurements e.g. 10 measurement samples used in legacy for channel quality evaluation.

In an operation 230, the UE device 110 may perform sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

In one embodiment, the UE device 110 may further transmit, to the network device 120, a message indicative of support of performing the sounding reference signal switching with reduced interruptions when performing the relaxed measurements for radio link monitoring and/or beam failure detection. On the other hand, the network device 120 may receive, from the UE device 110, the message indicative of support of performing the sounding reference signal switching with reduced interruptions when relaxed measurements for radio link monitoring and/or beam failure detection are performed by the UE device 110.

For example, the message indicative of support of performing the sounding reference signal switching with reduced interruptions can be in a capability message or any other RRC messages e.g. RRC reconfiguration complete message. In the capability message, the UE device 110 may indicate that it is able to omit or skip at least some of the measurements for RLM and/or BFD on RSs that are overlapping or interfering with the SRS switching, so that when relaxation criteria for RLM and/or BFD are fulfilled, the UE device 110 may keep SRS switching while performing relaxed measurements for RLM and/or BFD even if SRS switching is colliding with some of the RLM/BFD-RSs. Upon receiving the indication, the network device 120 is able to know that the UE device 110 may continue SRS switching whenever relaxed RLM/BFD measurements are performed by the UE device 110.

In one embodiment, performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection may further comprise: refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the sounding reference signal switching.

In another embodiment, performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection may further comprise: refraining from performing the measurements for radio link monitoring and/or beam failure detection to ensure the UE device 110 is able to evaluate the downlink radio link quality within a certain time period. For example, the UE device 110 may need to ensure the number of RSs being measured within the relaxed evaluation period is comparable with the number of RSs being measured within the legacy evaluation period e.g. 10 samples, after refraining from performing the measurements on one or more configured reference signals which are overlapping and/or interfering with the sounding reference signal switching. In one embodiment, the certain time period may refer to the minimum evaluation period over which the UE device 110 shall be able to evaluate the downlink radio link quality based on the relaxed measurements for radio link monitoring and/or beam failure detection.

In one embodiment, the UE device 110 may further be configured to receive, from the network device 120, a sounding reference signal switching configuration before the UE device 110 transmits to the network device 120 the message which is indicative of support of performing the sounding reference signal switching with reduced interruptions when the UE device 110 is performing the relaxed measurements for radio link monitoring and/or beam failure detection. On the other hand, the network device 120 may transmit, to the UE device 110, a sounding reference signal switching configuration before receiving the message from the UE device 110.

For example, the network device 120 can configure the UE device 110 a SRS switching configuration including certain SRS switching pattern, and/or the SRS resources. When receiving the configuration, the UE device 110 can evaluate if it can omit all or some of those RLM/BFD-RSs which are overlapping with the SRS switching while ensuring the evaluation of the downlink channel link quality and hence the UE device may indicate the support of performing the sounding reference signal switching with reduced interruptions when the UE device 110 is performing the relaxed measurements for radio link monitoring and/or beam failure detection based on the evaluation result. In addition, the UE device may further indicate the detailed collision status or the RS resources on which SRS switching can be performed to the network device 120. For instance, the UE device 110 may indicate that it will refrain from performing the measurements for radio link monitoring and/or beam failure detection on the first SRS resource and perform SRS switching without interruptions from relaxed RLM and/or BFD measurements. Upon receiving the indication, network device 120 may expect SRS transmission on the indicated first SRS resource.

In one embodiment, when the UE device 110 is performing sounding reference signal switching with reduced interruptions caused by performing measurements for radio link monitoring and/or beam failure detection, the UE device 110 may determine which of the sounding reference signal switching may survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection to obtain surviving sounding reference signal switching, and the UE device 110 may also refrain from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the surviving sounding reference signal switching.

For example, after receiving the SRS switching pattern configuration, the UE device 110 may determine which of the SRS will be dropped or continued based on the SRS switching pattern when the relaxed RLM/BFD measurements are performed. Alternatively, the UE device 110 may further determine on which of the SRS resources the SRS switching may survive without interruption from RLM/BFD measurements. Then when the one or more relaxation criteria are fulfilled, the UE device may refrain from performing the RLM/BFD measurements on those RSs which are overlapping/interfering with the SRS switching time which are determined to be continued.

In one embodiment, the UE device 110 may be further configured to transmit, to the network device 120, collision status information on which of the sounding reference signal switching may or may not survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection. For example, the information may be transmitted with the capability message discussed earlier. On the other hand, the network device 120 may receive, from the terminal device, information on which of the SRS switching may survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection.

For example, after evaluating if the UE device 110 can omit all or some of those RLM/BFD-RSs which are overlapping with the SRS switching, the UE device 110 may indicate the detailed collision status information to the network device 120. The collision status information may indicate that there are no collisions, that is, all SRS will be transmitted, or some collisions may occur. In one example, this indication may be signaled in addition to the UE capability message mentioned earlier. This detailed impact may also be included in other messages, such as RRC Reconfiguration complete messages. Upon receiving the information, the network device 120 may know if the UE device 110 will drop or continue SRS switching on the SRS resources whenever performing relaxed RLM/BFD measurements and which of the SRS resources the SRS switching may survive without interruption from RLM/BFD measurements.

According to the present disclosure, when the UE device 110 is allowed to perform relaxed measurements for RLM or BFD, the UE device 110 may refrain from performing the RLM and/or BFD measurements from those RSs which are overlapping or interfering with the SRS switching time. This applies to not only relaxed measurements for RLM and/or BFD but also relaxed SSB-based and CSI-RS based measurements if relaxation can be also applied.

For example, FIG. 3 shows an exemplary scenario, where SRS switching interruptions are reduced when performing relaxed measurements for RLM. The UE device 110 may align the RLM measurements and SRS switching such that SRS switching interruptions are minimized. That is, SRS switching are not interrupted when possible by reducing the collisions between the measured RLM-RS (radio link monitoring reference signal) and SRS switching time. Similar mechanism also applies to BFD measurement. As shown in FIG. 3, The UE is configured with relaxation criteria, such as good serving cell quality criteria, when performing RLM measurements. The UE device 110 may be configured with SRS antenna switching and the SRS resources are overlapping with some of the RLM-RSs. Before T1 when the relaxation criteria for relaxed RLM measurement are not fulfilled, RLM measurements are prioritized over SRS antenna switching, the UE device may drop the SRS switching when there are collisions between the measured RLM-RS and SRS switching. For example, as shown in FIG. 3, the first SRS block 321 is dropped because it collides with the RLM-RS 311 because the RLM measurement is prioritized before T1.

At T1, however, as shown in the FIG. 3, when the signal noise ratio (SNR) becomes high, and the serving cell quality is good, the good serving cell quality relaxation criteria for relaxed RLM measurement can be fulfilled. The UE device 110 can detect that relaxation criteria are fulfilled, and the UE device 110 may start to perform relaxed RLM measurements. The UE device 110 may be able to skip the RLM measurement on the RLM-RS 312, because there is collision between the RLM-RS 312 and the SRS switching 322. Therefore, the SRS switching 322 may be performed without interruption from the relaxed RLM measurements. Thus, the SRS switching 322 will survive. Similarly, the two

SRS blocks

323 and 324 will also survive, even if they are colliding with the RLM-

RSs

313 and 314.

Then at T2, when the signal noise ratio (SNR) is low, and the serving cell quality is not good, the relaxation criteria for relaxed RLM measurement cannot be fulfilled. The UE device 110 can detect that relaxation criteria are not fulfilled, and the UE device 110 may stop performing relaxed measurements. Then the UE device 110 needs to monitor all the configured RLM-RSs and can no longer skip the RLM measurements on the RLM-RS 315 which is colliding with the SRS switching 325. Therefore, the SRS switching 325 will be skipped due to the collision.

In one embodiment as shown in FIG. 3, a SRS block, such as the SRS bock 321, comprises the SRS switching time period which may include not only the SRS resources configured in SRS antenna port switching, but also include the guard period between the consecutive SRS switching, and/or the transient period before and after the SRS transmission. Similar mechanism also applies to SRS carrier based switching.

In another example, the UE device 110’s capability on SRS antenna switching (srs-TxSwitch) can be extended to indicate if it can omit RLM-RSs when relaxed RLM is triggered. For instance, txSwitchOmitRelaxedRLM can be set to indicate the SRS switching will not be interrupted when conditions for relaxed RLM/BFD measurements are fulfilled. This is set when RLM/BFD relaxation is configured. Similarly, the UE may also indicate via CarrierSwitchOmitRelaxedRLM if it can omit RLM-RSs overlapping with SRS carrier based switching when relaxed RLM is enabled. For both alternatives the UE can indicate that the SRS switching will not be interrupted when UE conditions for relaxed RLM/BFD measurements are fulfilled, or reduced SRS switching interruption is possible when UE conditions for relaxed RLM/BFD measurements are fulfilled. This applies not only to RLM measurements but also BFD measurements.

This disclosure accounts both the UE device 110’s need to perform SRS transmissions when overlapping with RSs used for RLM/BFD and the UE device’s need to perform relaxed measurements for RLM and/or BFD to save power. According to the present disclosure, usage of measurements for RLM or BFD will be facilitated and SRS switching will also be optimized at the same time.

Fig. 4 is a block diagram illustrating a communication network 400 in which example embodiments of the present disclosure can be implemented. The communication network 400 may be a part of a larger communication network or system. As shown in Fig. 4, the communication network 400 may include a terminal device 410 which may be implemented as the UE device 110 discussed above, and a network device 420 which may be implemented as the base station (gNB) 120 discussed above.

Referring to Fig. 4, the terminal device 410 may comprise one or more processors 411, one or more memories 412 and one or more transceivers 413 interconnected through one or more buses 414. The one or more buses 414 may be address, data, or control buses, and may include any interconnection mechanism such as series of lines on a motherboard or integrated circuit, copper cables, optical fibers, or other electrical/optical communication equipment, and the like. Each of the one or more transceivers 413 may comprise a receiver and a transmitter, which are connected to a plurality of antennas 416. The plurality of antennas 416 may form an antenna array to perform beamforming communication with the network device 420. The one or more memories 412 may include computer program code 415. The one or more memories 412 and the computer program code 415 may be configured to, when executed by the one or more processors 411, cause the terminal device 410 to perform operations and procedures relating to the UE device 110 as described above.

The network device 420 may be implemented as a single network node, or disaggregated/distributed over two or more network nodes, such as a central unit (CU) , a distributed unit (DU) , a remote radio head-end (RRH) , using different functional-split architectures and different interfaces. The network device 420 may comprise one or more processors 421, one or more memories 422, one or more transceivers 423 and one or more network interfaces 427 interconnected through one or more buses 424. The one or more buses 424 may be address, data, or control buses, and may include any interconnection mechanism such as a series of lines on a motherboard or integrated circuit, copper cables, optical fibers, or other electrical/optical communication equipment, and the like. Each of the one or more transceivers 423 may comprise a receiver and a transmitter, which are connected to a plurality of antennas 426. The network device 420 may operate as a base station for the terminal device 410 and wirelessly communicate with the terminal device 410 through the plurality of antennas 426. The plurality of antennas 426 may form an antenna array to perform beamforming communication with the terminal device 410. The one or more network interfaces 427 may provide wired or wireless communication links through which the network device 420 may communicate with other network devices, entities or functions. The one or more memories 422 may include computer program code 425. The one or more memories 422 and the computer program code 425 may be configured to, when executed by the one or more processors 421, cause the network device 420 to perform operations and procedures relating to the base station (gNB) 120 as described above.

The one or

more processors

411, 421 discussed above may be of any appropriate type that is suitable for the local technical network, and may include one or more of general purpose processors, special purpose processor, microprocessors, a digital signal processor (DSP) , one or more processors in a processor based multi-core processor architecture, as well as dedicated processors such as those developed based on Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuit (ASIC) . The one or

more processors

411, 421 may be configured to control other elements of the UE/network device and operate in cooperation with them to implement the procedures discussed above.

The one or

more memories

412, 422 may include at least one storage medium in various forms, such as a volatile memory and/or a non-volatile memory. The volatile memory may include but not limited to for example a random access memory (RAM) or a cache. The non-volatile memory may include but not limited to for example a read only memory (ROM) , a hard disk, a flash memory, and the like. Further, the one or

more memories

412, 422 may include but not limited to an electric, a magnetic, an optical, an electromagnetic, an infrared, or a semiconductor system, apparatus, or device or any combination of above.

FIG. 5 shows a flow chart illustrating an example method 500 for reducing sounding reference signal switching interruptions according to an embodiment of the present disclosure. The example method 500 may be performed for example at a terminal device such as the UE device 110.

Referring to the FIG. 5, the example method 500 may include a step 510 of receiving, from a network device, one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection; a step 520 of performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection, and a step 530 of performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

Details of the step 510 have been described in above descriptions with respect to at least the operation 210, and repetitive descriptions thereof are omitted here.

Details of the step 520 have been described in above descriptions with respect to at least the operation 220, and repetitive descriptions thereof are omitted here.

Details of the step 530 have been described in above descriptions with respect to at least the operation 230, and repetitive descriptions thereof are omitted here.

In some embodiments, refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the sounding reference signal switching comprises: refraining from performing the measurements for radio link monitoring and/or beam failure detection to ensure the UE is able to evaluate the downlink radio link quality within a certain time period.

In some embodiments, the information is transmitted with the message.

In some embodiments, the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises at least low mobility of the terminal device, good serving cell quality, and/or DRX cycle condition

FIG. 6 shows a flow chart illustrating an example method 600 for correspondence between downlink reference signal and uplink reference signal according to an embodiment of the present disclosure. The example method 600 may be performed for example at a network device such as the network device 120.

Referring to the FIG. 6, the example method 600 may include a step 610 of transmitting, to a terminal device, one or more relaxation criteria for radio link monitoring beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection. The terminal device performs sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.

Details of the step 610 have been described in above descriptions with respect to at least the operation 210, and descriptions thereof are omitted here.

In some embodiments, the information is received with the message.

FIG. 7 shows a block diagram illustrating an example apparatus 700 for reducing sounding reference signal switching interruptions according to an embodiment of the present disclosure. Apparatus, for example, may be at least part of the UE device 110 in above examples.

As shown in FIG. 7, the example apparatus 700 may include means 710 for performing the step 510 of the example method 500, means 720 for performing the step 520 of the example method 500, means 730 for performing the step 530 of the example method 500. In one or more another example embodiment, at least one I/O interface, at least one antenna element, and the like may also be included in the example apparatus 700.

In some example embodiments, examples of means in the example apparatus 700 may include circuitries. For example, an example of means 710 may include a circuitry configured to perform the step 510 of the example method 500, an example of means 720 may include a circuitry configured to perform the step 520 of the example method 500, and an example of means 730 may include a circuitry configured to perform the step 530 of the example method 500 In some example embodiments, examples of means may also include software modules and any other suitable function entities.

FIG. 8 shows a block diagram illustrating an example apparatus 800 for reducing sounding reference signal switching interruptions according to an embodiment of the present disclosure. Apparatus, for example, may be at least part of the network device 120 in above examples.

As shown in the FIG. 8, the example apparatus 800 may include means 810 for performing the step 610 of the example method 600

In some example embodiments, examples of means in the example apparatus 800 may include circuitries. For example, an example of means 810 may include a circuitry configured to perform the step 610 of the example method 600. In some example embodiments, examples of means may also include software modules and any other suitable function entities.

Correspondence definition in this disclosure precludes beam width and beam direction related aspects. Antenna port virtualization definition in this disclosure refers to antenna elements which are allocated for each antenna port. In correspondence mode antenna elements being allocated into each antenna port are expected to be the same between downlink (DL) and uplink (UL) .

The term “circuitry” throughout this disclosure 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) ; (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 one or all uses of this term in this disclosure, including in any claims. As a further example, as used in this disclosure, 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 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.

Another example embodiment may relate to computer program codes or instructions which may cause an apparatus to perform at least respective methods described above. Another example embodiment may be related to a computer readable medium having such computer program codes or instructions stored thereon. In some embodiments, such a computer readable medium may include at least one storage medium in various forms such as a volatile memory and/or a non-volatile memory. The volatile memory may include, but not limited to, for example, a RAM, a cache, and so on. The non-volatile memory may include, but not limited to, a ROM, a hard disk, a flash memory, and so on. The non-volatile memory may also include, but are not limited to, an electric, a magnetic, an optical, an electromagnetic, an infrared, or a semiconductor system, apparatus, or device or any combination of above.

Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise, ” “comprising, ” and the like are to be construed in an inclusive sense, as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to. ” The word “coupled” , as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Likewise, the word “connected” , as generally used herein, refers to two or more elements that may be either directly connected, or connected by way of one or more intermediate elements. Additionally, the words “herein, ” “above, ” “below, ” and words of similar import, when used in this application, shall refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the description using the singular or plural number may also include the plural or singular number respectively. The word “or” in reference to a list of two or more items, that word covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.

Moreover, conditional language used herein, such as, among others, “can, ” “could, ” “might, ” “may, ” “e.g., ” “for example, ” “such as” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or states. Thus, such conditional language is not generally intended to imply that features, elements and/or states are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without author input or prompting, whether these features, elements and/or states are included or are to be performed in any particular embodiment.

As used herein, the term "determine/determining" (and grammatical variants thereof) can include, not least: calculating, computing, processing, deriving, measuring, investigating, looking up (for example, looking up in a table, a database or another data structure) , ascertaining and the like. Also, "determining" can include receiving (for example, receiving information) , accessing (for example, accessing data in a memory) , obtaining and the like. Also, "determine/determining" can include resolving, selecting, choosing, establishing, and the like.

While some embodiments have been described, these embodiments have been presented by way of example, and are not intended to limit the scope of the disclosure. Indeed, apparatus, methods, and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the disclosure. For example, while blocks are presented in a given arrangement, alternative embodiments may perform similar functionalities with different components and/or circuit topologies, and some blocks may be deleted, moved, added, subdivided, combined, and/or modified. At least one of these blocks may be implemented in a variety of different ways. The order of these blocks may also be changed. Any suitable combination of the elements and actions of some embodiments described above can be combined to provide further embodiments. Accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.

Abbreviations used in the description and/or in the figures are defined as follows:

5G fifth generation

BS base station

BFD beam failure detection

CSI-RS channel state information reference signal

gNB next generation NodeB /5G base station

PUCCH physical uplink control channel

PUSCH physical uplink shared channel

RLM radio link monitoring

RRC radio resource control

SSB Synchronization Signal/PBCH block

UE user equipment

Claims

A terminal device comprising:

at least one processor; and

at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the terminal device to perform:

receiving, from a network device, one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection;

performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection; and

performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.
The terminal device of Claim 1, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to perform:

transmitting, to a network device, a message indicative of support of performing the sounding reference signal switching with reduced interruptions when performing the relaxed measurements for radio link monitoring and/or beam failure detection.
The terminal device of Claim 2, wherein performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection comprises:

refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the sounding reference signal switching.
The terminal device of Claim 3, wherein refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the sounding reference signal switching comprises:

refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection to ensure the terminal device is able to evaluate the downlink radio link quality within a certain time period.
The terminal device of Claim 2, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to perform:

receiving, from the network device, a sounding reference signal switching configuration before transmitting, to a network device, the message.
The terminal device of Claim 5, wherein performing sounding reference signal switching with reduced interruptions caused by performing measurements for radio link monitoring and/or beam failure detection comprises:

determining which of the sounding reference signal switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection to obtain surviving sounding reference signal switching; and

refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the surviving sounding reference signal switching.
The terminal device of Claim 6, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the terminal device to perform:

transmitting, to the network device, information on which of the sounding reference signal switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection.
The terminal device of Claim 7, wherein the information is transmitted with the message.
The terminal device of Claim 1, wherein the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises at least low mobility of the terminal device, good serving cell quality, and/or DRX cycle condition.
The terminal device of Claim 1, wherein the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises dedicated indication from the network device to enable the terminal device to perform relaxed measurements for radio link monitoring and/or beam failure detection.
The terminal device of Claim 1, wherein the sounding reference signal switching comprises sounding reference signal antenna switching and/or sounding reference signal carrier based switching.
The terminal device of Claim 1, wherein the sounding reference signal switching comprises the time to transmit sounding reference signal, and/or the time for switching the antenna or carrier.
The terminal device of Claim 4, wherein the certain time period refers to the minimum evaluation period over which the terminal device shall be able to evaluate the downlink radio link quality based on the relaxed measurements for radio link monitoring and/or beam failure detection.
A network device comprising:

at least one processor; and

at least one memory comprising computer program code, the at least one memory and the computer program code being configured to, with the at least one processor, cause the terminal device to perform:

transmitting, to a terminal device, one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection,

wherein the terminal device performs sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.
The network device of claim 14, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network device to perform:

receiving, from the terminal device, a message indicative of support of performing the sounding reference signal switching with reduced interruptions when relaxed measurements for radio link monitoring and/or beam failure detection are performed by the terminal device.
The network device of claim 14, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network device to perform:

transmitting, to the terminal device, a sounding reference signal switching configuration before receiving the message from the terminal device.
The network device of claim 14, wherein the at least one memory and the computer program code are further configured to, with the at least one processor, cause the network device to perform:

receiving, from the terminal device, information on which of the SRAS switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection.
The network device of Claim 17, wherein the information is received with the message.
The network device of Claim 15, wherein the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises at least low mobility of the terminal device, good serving cell quality, and/or DRX cycle condition.
The network device of Claim 14, wherein the sounding reference signal switching comprises sounding reference signal antenna switching and/or sounding reference signal carrier based switching.
The network device of Claim 14, wherein the sounding reference signal switching the sounding reference signal switching comprises the time to transmit sounding reference signal, and/or the time for switching the antenna or carrier.
A method implemented at a terminal device comprising:

receiving, from a network device, one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection;

performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection; and

performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.
The method of Claim 22, further comprising:

transmitting, to a network device, a message indicative of support of performing the sounding reference signal switching with reduced interruptions when performing the relaxed measurements for radio link monitoring and/or beam failure detection.
The method of Claim 23, wherein performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection comprises:

refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the sounding reference signal switching.
The method of Claim 24, wherein refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the sounding reference signal switching comprises:

refraining from performing the measurements for radio link monitoring and/or beam failure detection to ensure the terminal device is able to evaluate the downlink radio link quality within a certain time period.
The method of Claim 23, further comprising:

receiving, from the network device, a sounding reference signal switching configuration before transmitting, to a network device, the message.
The method of Claim 26, wherein performing sounding reference signal switching with reduced interruptions caused by performing measurements for radio link monitoring and/or beam failure detection comprises:

determining which of the sounding reference signal switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection to obtain surviving sounding reference signal switching; and

refraining from performing the relaxed measurements for radio link monitoring and/or beam failure detection on one or more configured reference signals which are overlapping and/or interfering with the surviving sounding reference signal switching.
The method of Claim 27, further comprising:

transmitting, to the network device, information on which of the sounding reference signal switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection.
The method of Claim 28, wherein the information is transmitted with the message.
The method of Claim 22, wherein the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises at least low mobility of the terminal device, good serving cell quality, and/or DRX cycle condition.
The method of Claim 22, wherein the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises dedicated indication from network to enable the terminal device to perform relaxed measurements for radio link monitoring and/or beam failure detection.
The method of Claim 22, wherein the sounding reference signal switching comprises sounding reference signal antenna switching and/or sounding reference signal carrier based switching.
The method of any of claims 32, wherein the sounding reference signal switching comprises the time to transmit sounding reference signal, and/or the time for switching the antenna or carrier.
The terminal device of Claim 25, wherein the certain time period refers to the minimum evaluation period over which the terminal device shall be able to evaluate the downlink radio link quality based on the relaxed measurements for radio link monitoring and/or beam failure detection.
A method implemented at a network device in a communication network, comprising:

transmitting, to a terminal device, one or more relaxation criteria for radio link monitoring beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection,

wherein the terminal device performs sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.
The method of claim 33, further comprising:

receiving, from the terminal device, a message indicative of support of performing the sounding reference signal switching with reduced interruptions when relaxed measurements for radio link monitoring and/or beam failure detection are performed by the terminal device.
The method of claim 33, further comprising:

transmitting, to the terminal device, a sounding reference signal switching configuration before receiving the message from the terminal device.
The method of claim 33, further comprising:

receiving, from the terminal device, information on which of the SRAS switching survive free from interruptions caused by the relaxed measurements for radio link monitoring and/or beam failure detection.
The method of claim 36, wherein the information is received with the message.
The method of Claim 34, wherein the one or more relaxation criteria for radio link monitoring and/or beam failure detection comprises at least low mobility of the terminal device, good serving cell quality, and/or DRX cycle condition.
The method of claim 33, wherein the sounding reference signal switching comprises sounding reference signal antenna switching and/or sounding reference signal carrier based switching.
The method of claim 33, wherein the sounding reference signal switching the sounding reference signal switching comprises the time to transmit sounding reference signal, and/or the time for switching the antenna or carrier.
An apparatus in a communication network, comprising:

means for receiving, from a network device, one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection;

means for performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection; and

means for performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.
An apparatus in a communication network, comprising:

means for transmitting, to a terminal device, one or more relaxation criteria for radio link monitoring beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection,

wherein the terminal device performs sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.
A computer program comprising instructions stored on a computer readable medium, the instructions, when executed by at least one processor of a terminal device in a communication network, causing the terminal device to perform:

receiving, from a network device, one or more relaxation criteria for radio link monitoring and/or beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection;

performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection; and

performing sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.
A computer program comprising instructions stored on a computer readable medium, the instructions, when executed by at least one processor of a network device in a communication network, causing the network device to perform:

transmitting, to a terminal device, one or more relaxation criteria for radio link monitoring beam failure detection for performing relaxed measurements for radio link monitoring and/or beam failure detection,

wherein the terminal device performs sounding reference signal switching with reduced interruptions caused by performing relaxed measurements for radio link monitoring and/or beam failure detection when the one or more relaxation criteria for radio link monitoring and/or beam failure detection are fulfilled for performing the relaxed measurements for radio link monitoring and/or beam failure detection.