WO2024259596A1

WO2024259596A1 - Enhancements on secondary cell group activation

Info

Publication number: WO2024259596A1
Application number: PCT/CN2023/101455
Authority: WO
Inventors: Chunli Wu; Samuli Heikki TURTINEN; Jussi-Pekka Koskinen
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: 2023-06-20
Filing date: 2023-06-20
Publication date: 2024-12-26
Anticipated expiration: 2025-12-20

Abstract

Example embodiments of the present disclosure relate to enhancements on secondary cell group (SCG) activation. An apparatus determines that a beam failure is detected on a primary secondary cell in a SCG configured for the first apparatus upon activation of the SCG. The apparatus determines that at least one contention free resource for beam failure recovery is configured for the first apparatus. Based on the beam failure being detected on the primary secondary cell in the SCG upon activation of the SCG and the at least one contention free resource for beam failure recovery being configured for the first apparatus, the apparatus utilizes the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the SCG. In this way, contention free resources for BFR can be utilized for random access required for SCG activation.

Description

ENHANCEMENTS ON SECONDARY CELL GROUP ACTIVATION

FIELDS

Various example embodiments of the present disclosure generally relate to the field of telecommunication, and in particular, to methods, devices, apparatuses and computer readable storage media for secondary cell group (SCG) activation.

BACKGROUND

In E-UTRA-NR dual connectivity (EN-DC) , NR-E-UTRA dual connectivity (NE-DC) or New Radio dual connectivity (NR-DC) , UE can be served by a master cell group (MCG) and a secondary cell group (SCG) . The MCG and SCG are provided by a master node (MN) and a secondary node (SN) respectively. To enable reducing UE battery consumption while having fast usage of SCG, an activation/deactivation mechanism of SCG is supported. The MN may configure the SCG as activated and deactivated upon, for example, primary secondary cell (PSCell) addition, PSCell change, RRC Resume, RRC reconfiguration, or handover.

In case that the SCG is configured as deactivated, all the secondary cells (SCells) in the SCG are in deactivated state, and there is no transmission via SCG radio link control (RLC) bearers. In addition, the UE does not perform random access towards the PSCell. Upon SCG activation, if beams are in failure condition on PSCell while the SCG is deactivated, UE initiates a Random Access (RA) procedure to ensure DL beam synchronization at SCG activation.

SUMMARY

In a first aspect of the present disclosure, there is provided an apparatus. The apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: determine that a beam failure is detected on a primary secondary cell in a secondary cell group configured for the apparatus upon activation of the secondary cell group; determine that at least one contention free resource for beam failure recovery is configured for the apparatus; and based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group and the at least one contention free resource for beam failure recovery being configured for the apparatus, utilize the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the secondary cell group.

In a second aspect of the present disclosure, there is provided an apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to:receive, from a terminal device, a random access request for a random access procedure in a secondary cell group configured for the terminal device, wherein the random access procedure is to be performed based on a need to activate the secondary cell group by utilizing at least one contention free resource for beam failure recovery; and transmit, to the terminal device, a random access response.

In a third aspect of the present disclosure, there is provided a method. The method comprises: determining, at an apparatus, that a beam failure is detected on a primary secondary cell in a secondary cell group configured for the apparatus upon activation of the secondary cell group; determining that at least one contention free resource for beam failure recovery is configured for the apparatus; and based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group and the at least one contention free resource for beam failure recovery being configured for the apparatus, utilizing the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the secondary cell group.

In a fourth aspect of the present disclosure, there is provided a method. The method comprises: receiving, at an apparatus and from a terminal device, a random access request for a random access procedure in a secondary cell group configured for the terminal device, wherein the random access procedure is to be performed based on a need to activate the secondary cell group by utilizing at least one contention free resource for beam failure recovery; and transmitting, to the terminal device, a random access response.

In a fifth aspect of the present disclosure, there is provided an apparatus. The apparatus comprises means for determining that a beam failure is detected on a primary secondary cell in a secondary cell group configured for the apparatus upon activation of the secondary cell group; means for determining that at least one contention free resource for beam failure recovery is configured for the apparatus; and means for based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group and the at least one contention free resource for beam failure recovery being configured for the apparatus, utilizing the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the secondary cell group.

In a sixth aspect of the present disclosure, there is provided an apparatus. The apparatus comprises means for receiving, from a terminal device, a random access request for a random access procedure in a secondary cell group configured for the terminal device, wherein the random access procedure is to be performed based on a need to activate the secondary cell group by utilizing at least one contention free resource for beam failure recovery; and means for transmitting, to the terminal device, a random access response.

In a seventh aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the third aspect.

In an eighth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fourth aspect.

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

BRIEF DESCRIPTION OF THE DRAWINGS

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

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

FIG. 2 illustrates a signaling chart for a communication process according to some example embodiments of the present disclosure;

FIG. 3 illustrates a flowchart of a method implemented at an apparatus according to some example embodiments of the present disclosure;

FIG. 4 illustrates a flowchart of a method implemented at an apparatus according to some example embodiments of the present disclosure;

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

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

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

DETAILED DESCRIPTION

Principles 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. Embodiments 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, ” “second” and the like 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.

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 herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

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

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

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

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

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

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

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

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

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR) , Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the 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) , an NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

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

As used herein, the term “resource, ” “transmission resource, ” “resource block, ” “physical resource block” (PRB) , “uplink resource, ” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and/or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

As used herein, the term “dual connectivity (DC) ” used herein may refer to a mechanism that allows a terminal device simultaneously connects with two network nodes or allows the terminal device to aggregate signals in difference communication protocols. In DC, the terminal device may be connected to two cells, or in general, two cell groups, the MCG and the SCG. The term “master cell group (MCG) ” used herein may refer to a cell group that is provided by a MN and includes at least a primary cell where the terminal device initiates an initial random access, when the DC is applied. The term “secondary cell group (SCG) ” used herein may refer to a cell group that is provided by a SN and does not include the cell where the terminal device initiates the initial random access when the DC is applied.

As used herein, the term “primary cell (PCell) ” may refer to a cell in MCG that operates on a primary frequency in which the terminal device either performs an initial connection establishment procedure or initiates the connection re-establishment procedure. The term “secondary cell (SCell) ” used herein may refer to for the terminal device configured with a carrier aggregation (CA) , a cell providing addition radio resources. Other cells in the MCG may be referred to as SCells. The term “primary secondary cell (PSCell) ” used herein may refer to a cell in SCG in which the terminal device performs a random access when performing a reconfiguration with synchronization procedure. Other cells in the SCG may also referred to as SCells. The PCell and the SCell in the MCG may be operated by CA. The PSCell and the SCell in the SCG may also be operated by CA. For Dual Connectivity operation the term “special cell (SpCell) ” refers to the PCell of the MCG or the PSCell of the SCG depending on if a medium access control (MAC) entity is associated to the MCG or the SCG, respectively. Otherwise, the term “SpCell” may refer to the PCell. A SpCell may support a physical uplink control channel (PUCCH) transmission and a contention-based random access.

The term “beam failure recovery instance” used herein may refer to an occurrence where a reference signal received power on a beam is less than a threshold value. The term “beam failure” used herein may refer to a situation where a beam is not suitable for communication due to poor channel condition. The beam failure may be declared when the number of beam failure instances reaches a threshold number. The term “beam failure recovery (BFR) ” used herein may refer to a procedure that is used when a terminal device is suffering from poor channel condition. The term “beam failure instance counter” used herein may refer to a counter for beam failure instance indication which is initially set to 0.

The term “random access procedure” used herein may refer to a procedure where a terminal device establishes a connection, requests resources, gets uplink synchronization, gets beam recovery etc. with a network device. There may be a contention based random access procedure and a contention free random access procedure.

FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure can be implemented. The communication environment 100 is a communication network that supports DC. In the communication environment 100, a first apparatus 110, a second apparatus 120 and a third apparatus 130 may communicate with each other.

The first apparatus 110 may be a terminal device, such as a UE. The second apparatus 120 and the third apparatus 130 may be network devices, such as gNB s. The first apparatus 110 may be configured for DC, and thus served by both the second apparatus 120 and the third apparatus 130. In the example of FIG. 1, the second apparatus 120 acts as a MN, and provides the MCG, which may include one cell 122-1 or a plurality of cells 122-1 to 122-M, where the cell 122-1 may be the PCell (which may also be referred to as PCell 122-1 hereinafter) , while the rest of the cells in MCG may be SCells. The third apparatus 130 acts as a SN, and provides the SCG, which may include one cell 132-1 or a plurality of cells 132-1 to 132-N, where the cell 132-1 may be the PSCell (which may also be referred to as PSCell 132-1 hereinafter) , while the rest of the cells in SCG may be SCells.

In some example embodiments, MN, i.e., the second apparatus 120 may configure the SCG as activated or deactivated, for example, upon e.g., PSCell addition, PSCell change, RRC Resume, RRC reconfiguration, or handover. In case the SCG is configured as deactivated, the first apparatus 110 may not perform random access towards the PSCell. The network can trigger SCG radio resource control (RRC) reconfiguration (e.g., PSCell change, configuration update) when deactivating the SCG and while the SCG is in deactivated state.

SCG activation may be requested by the MN (i.e., the second apparatus 120) , by the SN (i.e., the third apparatus 130) , or by the UE (i.e., the first apparatus 110) . SCG deactivation may be requested by the MN and by the SN. For UL data arrival on SCG bearer (s) while the SCG is deactivated, the first apparatus 110 may indicate to the MN that it has UL data to transmit over SCG bearer. During a handover procedure, the target MN can indicate the SCG state in the RRC reconfiguration message sent to the first apparatus 110 by the source MN. Network can configure whether the UE is allowed to indicate a preference for SCG deactivation to the MN.

In some example embodiments, upon SCG deactivation and while the SCG is deactivated, the network may ensure that there is no uplink control protocol data unit (PDU) transmission to the deactivated SCG. For example, the network may release statusReportRequired from Packet Data Convergence Protocol (PDCP) entities of SCG bearers if configured, the network does not perform quality of service (QoS) flow remapping from a data radio bearer (DRB) associated to the deactivated SCG to another DRB. The network ensures the SCG is activated while PDCP duplication is activated for SCG radio link control (RLC) entities associated with a PDCP entity. Upon SCG (de) activation, it may be up to the network to ensure there is no pending service data units (SDUs) or PDUs in SCG RLC entity (e.g., instructs the first apparatus 110 to perform PDCP data recovery and RLC re-establishment/release, if needed) .

While the SCG is deactivated, the first apparatus 110 may not transmit physical uplink shared channel (PUSCH) , sounding reference signal (SRS) and channel state information (CSI) report on SCG, and the first apparatus 110 may not be required to monitor physical downlink control channel (PDCCH) or receive downlink shared channel (DL-SCH) on SCG. If configured by the network, the first apparatus 110 may perform radio link monitoring on the SCG and beam failure detection on the SCG while SCG is deactivated. In case of SCG activation without performing random access, the network can indicate transmission configuration indicator (TCI) states to the first apparatus 110 for PDCCH/PDSCH reception on primary secondary cell (PSCell) (for example, the cell 130-1) . If not provided, the first apparatus 110 may use previously activated TCI states.

In some example embodiments, a medium access control (MAC) entity at the first apparatus 110 may be configured by radio resource control (RRC) per Serving Cell or per BFD-RS set with a beam failure recovery procedure which is used for indicating to the serving gNB of a new synchronization signal block (SSB) or CSI-RS when a beam failure is detected on the serving SSB (s) /CSI-RS (s) . Beam failure may be detected by counting beam failure instance indications from lower layers to the MAC entity. If beamFailureRecoveryConfig is reconfigured by upper layers during an ongoing random access procedure for beam failure recovery for SpCell, the MAC entity may stop the ongoing random access procedure and initiate a random access procedure using the new configuration. The Serving Cell may be configured with two BFD-RS sets, if failureDetectionSet1 and failureDetectionSet2 are configured for the active DL bandwidth part (BWP) of the Serving Cell. When the SCG is deactivated, the first apparatus 110 may perform beam failure detection on the PSCell, if bfd-and-RLM is set to true. For example, the first apparatus 110 may detect a beam failure based on a reference signal. The first apparatus 110 may also search a candidate beam with good quality. If a predefined number of beam failures is detected, a beam failure recovery process with the candidate beam may be triggered. The predefined number of beam failures to trigger this process is defined by a beam failure instance maximum count in RRC configuration. Upon SCG activation, the first apparatus 110 may transmit a request (for example, message 1) for a random access procedure with a unique identity (i.e., a beam failure recovery request) of the first apparatus 110 to the second apparatus 120. The second apparatus 120 may reply to the request. For example, the second apparatus 120 may transmit downlink control information (DCI) for message 2 via a search space that is specified by a recovery search space ID.

In some example embodiments, upon SCG activation, if beams are in failure condition on PSCell while the SCG is deactivated, the first apparatus 110 may initiate a random access procedure to ensure DL beam synchronization at SCG activation.

In a case where the random access procedure is initiated for SpCell beam failure recovery and the beamFailureRecoveryConfig is configured for the active UL BWP of the selected carrier, the MAC entity at the first apparatus 110 may start the beamFailureRecoveryTimer, if configured.

In some example embodiments, the third apparatus 130 may configure the contention-free random access (CFRA) resources for beam failure recovery (BFR) for the first apparatus 110. In a case where the random access procedure is initiated for SpCell beam failure recovery, the beamFailureRecoveryConfig is either running or not configured, the CFRA resources for beam failure recovery request associated with any of the SSBs and/or CSI-RSs have been explicitly provided by RRC, and at least one of the SSBs with SS-RSRP above rsrp-ThresholdSSB amongst the SSBs in candidateBeamRSList or the CSI-RSs with CSI-RSRP above rsrp-ThresholdCSI-RS amongst the CSI-RSs in candidateBeamRSList is available, the MAC entity at the first apparatus 110 may select an SSB with SS-RSRP above rsrp-ThresholdSSB amongst the SSBs in candidateBeamRSList or a CSI-RS with CSI-RSRP above rsrp-ThresholdCSI-RS amongst the CSI-RSs in candidateBeamRSList. The beamFailureRecoveryTimer (if configured) may dictate that the first apparatus 110 can use the configured CFRA resources for BFR in the random access procedure. If CSI-RS is selected, and there is no ra-PreambleIndex associated with the selected CSI-RS, the MAC entity at the first apparatus 110 may set the PREAMBLE_INDEX to a ra-PreambleIndex corresponding to the SSB in candidateBeamRSList which is quasi-colocated with the selected CSI-RS. Otherwise, the MAC entity at the first apparatus 110 may set the PREAMBLE_INDEX to a ra-PreambleIndex corresponding to the selected SSB or CSI-RS from the set of random access preambles for beam failure recovery request.

In the following, for the purpose of illustration, some example embodiments are described with the first apparatus 110 operating as a terminal device, while the second apparatus 120 and the third apparatus 130 operating as network devices. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other device.

In some example embodiments, if the first apparatus 110 is a terminal device, and the second apparatus 120 and the third apparatus 130 are network devices, a link from the second apparatus 120/the third apparatus 130 to the first apparatus 110 is referred to as a downlink (DL) , and a link from the first apparatus 110 to the second apparatus 120/the third apparatus 130 is referred to as an uplink (UL) . In DL, the second apparatus 120/the third apparatus 130 is a transmitting (TX) device (or a transmitter) , and the first apparatus 110 is a receiving (RX) device (or a receiver) . In UL, the first apparatus 110 is a TX device (or a transmitter) , and the second apparatus 120/the third apparatus 130 is a RX device (or a receiver) .

Communications in the communication 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 (5G) , the sixth generation (6G) , and 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.

A random access procedure may be initiated upon SCG activation. However, this random access procedure may not be performed for beam failure recovery in SpCell but is just a regular random access procedure, e.g. for UL timing synchronization. This means that even though the beams are in failure condition, and UE is configured with beamFailureRecoveryConfig and with CFRA resources for BFR, the UE cannot use these resources for the random access procedure. As a result, the UE cannot flexibly utilize the CFRA resources configured for BFR to SCG activation, leading to the unnecessary power consumption.

According to some example embodiments of the present disclosure, there is provided a solution for SCG activation. In particular, the first apparatus determines determine that a beam failure is detected on a secondary cell group configured for the first apparatus upon activation of the secondary cell group. The first apparatus determines that at least one contention free resource for beam failure recovery is configured for the first apparatus. Based on the beam failure being detected on the secondary cell group upon activation of the secondary cell group and the at least one contention free resource for beam failure recovery being configured for the first apparatus, the first apparatus utilizes the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the secondary cell group.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

Reference is now made to FIG. 2, which illustrates a signaling chart for a communication process 200 according to some example embodiments of the present disclosure. The communication process 200 may involve a terminal device (e.g., the first apparatus 110) , and network devices (e.g., the second apparatus 120, the third apparatus 130) . For the purpose of discussion, reference is made to FIG. 1 to describe the communication process 200.

At the beginning of the process 200, the SCG is deactivated. The first apparatus 110 may be configured to monitor the beams on SCG during SCG deactivation, for example, by performing beam failure detection on the PSCell 132-1.

In some example embodiments, a beam failure instance counter (e.g., BFI_COUNTER) may be used for counting the number of beam failures. In particular, when the first apparatus 110 initially detects that a beam radio link quality is below a threshold, a beam failure is reported to the MAC layer and the beam failure instance counter is incremented and a beam failure detection timer is started. If a value of the beam failure instance counter is equal to or exceeds a threshold value (e.g., beamFailureInstanceMaxCount) before expiration of the beam failure detection timer, it means that there is beam failure in the PSCell 132-1. In this case, a beam failure recovery may be needed. It should be understood that the above mechanism is only given only for illustrative purpose, any other failure detection mechanism may also be applicable to the embodiments of the present disclosure.

In some example embodiments, the second apparatus 120 may transmit (205) a configuration of at least one contention free resource for beam failure recovery to the first apparatus 110. The at least one contention free resource may be, for example, CFRA resources configured via RRC message.

The SCG may then be configured as activated. In some example embodiments, the second apparatus 120 may transmit (210) an indication of activation of the SCG to the first apparatus 110. For example, the indication of activation of the SCG may be transmitted via RRC signaling. In some example embodiments, in response to or based on the indication, the RRC layer at the first apparatus 110 may indicate to the MAC layer at the first apparatus 110 to activate SCG. Additionally, upon receipt of the indication of activation of the SCG, the first apparatus 110 may determine whether a beam failure is detected on the SCG.

In some example embodiments, the first apparatus 110 then determines (215) that a beam failure is detected on a PSCell 132-1 in the SCG upon activation of the SCG.

For example, upon receipt of the indication of activation of the SCG, the first apparatus 110 may determine whether a beam failure is detected on the PSCell 132-1 in the SCG based on the value of the beam failure instance co unter associated with the PSCell 132-1. If the value of the beam failure instance counter associated with the PSCell 132-1 is equal to or exceeds the threshold value (e.g., BFI_COUNTER >=beamFailureInstanceMaxCount) upon activation of the SCG (e.g., upon reception of the indication of activation of the SCG or upon reception of the indication from RRC layer to the MAC layer) , the first apparatus 110 may determine that the beam failure is detected on the PSCell 132-1 in the SCG. In this case, a random access procedure is to be performed based on a need to activate the SCG or for activating the SCG. The need to activate the SCG or need for activating the SCG may be based on the received indication of activation of the SCG.

The first apparatus 110 may then determine if any contention free resource is configured for beam failure recovery. The at least one contention free resource may be configured by the third apparatus 130. In some example embodiments, the first apparatus 110 then determines (220) that at least one contention free resource for beam failure recovery is configured for the first apparatus 110.

Based on the beam failure being detected on the PSCell 132-1 in the SCG upon activation of the SCG and the at least one contention free resource for beam failure recovery being configured for the first apparatus 110, the first apparatus 110 utilizes (225) the at least one contention free resource for beam failure recovery for the random access procedure that is performed based on a need to activate the SCG. That is, based on determining (215) and determining (220) , the first apparatus may utilize the at least one contention free resources for the random access procedure. For example, the first apparatus 110 utilizes the at least one contention free resource for beam failure recovery for a random access procedure that is triggered based on a need for activating the secondary cell group. For example, the random access procedure may be triggered based on the indication of activation of the SCG. A random access procedure for activation of the SCG may denote that the random access procedure is triggered based on the SCG having been activated. In other words, the random access procedure may be triggered by the need of RA procedure due to the activation of the SCG. The random access procedure for (i.e. due to) activation off the SCG can be used to get to uplink synchronization for the SCG or PTAG of the SCG. In other words, the random access procedure may be triggered to acquire uplink synchronization while the SCG is activated already. The random access procedure may be performed over a random access channel after the SCG is activated. For example, the MAC layer may perform the random access procedure over the random access channel on the cell after the SCG is activated.

In some example embodiments, in a case where the CFRA resources is configured for beam failure recovery in the SpCell, a beam failure recovery timer (i.e., beamFailureRecoveryTimer) may be used for controlling the CFRA procedure. For example, if the CFRA procedure does not succeed before expiration of the beam failure recovery timer, the CFRA may not continue to be used.

In some example embodiments, if the beam failure is detected on the PSCell 132-1 in the SCG (e.g., BFI_COUNTER >= beamFailureInstanceMaxCount) upon SCG activation and at least one CFRA resource for beam failure recovery is configured, the CFRA for beam failure recovery is available for the random access procedure regardless of whether a beam failure recovery timer is running or configured for the PSCell (if other conditions for CFRA are met) .

Alternatively, or additionally, in some other embodiments, based on the beam failure being detected on the SCG upon activation of the SCG, the first apparatus 110 may further determine whether the beam failure recovery timer is configured for the first apparatus 110. If the beam failure recovery timer being configured, the first apparatus 110 may start the beam failure recovery timer upon SCG activation.

The beam failure recovery timer may be started either upon the activation of the SCG, or alternatively, started upon initiation of the random access procedure. The random access procedure may be initiated by the first apparatus 110, for example. The random access procedure may be initiated by the first apparatus 110 transmitting random access request to the second apparatus 120. Thus, for example, the beam failure recovery timer may be started based on transmitting the random access request. In another example, the beam failure recovery timer may be started based on receiving indication of activation of the SCG.

In some example embodiments, after transmitting the random access request, the first apparatus 110 may then receive a random access response from the third apparatus 130.

Given the beam failure condition, the solution of SCG activation provided by the example embodiments of the present disclosure ensures that the UE can utilize configured CFRA resources for beam failure recovery upon SCG activation if the random access procedure is required for SCG activation. In this way, unnecessary power consumption at UE can be reduced.

Table 1 shows an example of random access resource selection according to the example embodiments, which may be implemented into the TS 38.321:

Table 1

Table 2 shows an example of activation/deactivation of SCG, which may be implemented into the TS 38.321:

Table 2

Table 3 shows an example of initiation of variable specific to random access type, which may be implemented into the TS 38.321:

Table 3

It is to be understood that the threshold numbers, configurations, values and functions given in the above embodiments are provided for illustrative purpose. Other threshold numbers, configurations, values and functions may also be applicable to implementations of the embodiments. Therefore, scope of the present disclosure is not limited in this regard.

FIG. 3 illustrates a flowchart of a method 300 implemented at an apparatus according to some example embodiments of the present disclosure. For example, the apparatus may be a terminal device, such as, the first apparatus 110 in FIG. 1. For the purpose of discussion, the method 300 will be described from the perspective of the first apparatus 110 in FIG. 1.

At block 310, the first apparatus 110 determines that a beam failure is detected on a primary secondary cell in a secondary cell group configured for the first apparatus 110 upon activation of the secondary cell group.

At block 320, the first apparatus 110 determines that at least one contention free resource for beam failure recovery is configured for the first apparatus.

At block 330, based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group and the at least one contention free resource for beam failure recovery being configured for the first apparatus, the first apparatus 110 utilizes the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the secondary cell group.

In some example embodiments, the first apparatus 110 may determine whether a value of a beam failure instance counter associated with the primary secondary cell is equal to or exceeds a threshold value upon activation of the secondary cell group. Based on the value of the beam failure instance counter associated with the primary secondary cell being equal to or exceeding the threshold value upon activation of the secondary cell group, the first apparatus 110 may determine the beam failure is detected on the primary secondary cell in the secondary cell group.

In some example embodiments, the first apparatus 110 may receive an indication of activation of the secondary cell group. The first apparatus 110 may determine whether a beam failure is detected on the primary secondary cell in the secondary cell group upon receipt of the indication.

In some example embodiments, the at least one contention free resource may be configured via a radio resource control message.

In some example embodiments, based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group, the first apparatus 110 may determine whether a beam failure recovery timer is configured for the first apparatus. Based on determining that the beam failure recovery timer is configured for the first apparatus 110, the first apparatus 110 may start the beam failure recovery timer.

In some example embodiments, the beam failure recovery timer may be started upon the activation of the secondary cell group.

In some example embodiments, the beam failure recovery timer may be started upon initiation of the random access procedure.

In some example embodiments, the first apparatus 110 may transmit, to a network device providing the SCG, a random access request for the random access procedure. The first apparatus 110 may then receive, from the network device, a random access response.

In some example embodiments, the first apparatus 110 may be a terminal device.

FIG. 4 shows a flowchart of an example method 400 implemented at an apparatus in accordance with some example embodiments of the present disclosure. For example, the apparatus may be a network device, such as, the third apparatus 130 shown in FIG. 1. For the purpose of discussion, the method 400 will be described from the perspective of the third apparatus 130 in FIG. 1.

At block 410, the third apparatus 130 receives, from a terminal device, a random access request for a random access procedure in a secondary cell group configured for the terminal device, wherein the random access procedure is to be performed based on a need to activate the secondary cell group by utilizing at least one contention free resource for beam failure recovery. The terminal device may be, for example, the first apparatus 110 in FIG. 1.

At block 420, the third apparatus 130 transmits, to the terminal device, a random access response.

In some example embodiments, the at least one contention free resource may be configured by the third apparatus 130.

In some example embodiments, the third apparatus 130 may be a network device.

In some example embodiments, an apparatus, which is also referred to as a first apparatus hereafter, capable of performing any of the method 300 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations 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. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1.

In some example embodiments, the first apparatus comprises means for determining that a beam failure is detected on a primary secondary cell in a secondary cell group configured for the first apparatus upon activation of the secondary cell group; means for determining that at least one contention free resource for beam failure recovery is configured for the first apparatus; and means for based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group and the at least one contention free resource for beam failure recovery being configured for the first apparatus, utilizing the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the secondary cell group.

In some example embodiments, the first apparatus further comprises means for determining whether a value of a beam failure instance counter associated with the primary secondary cell is equal to or exceeds a threshold value upon activation of the secondary cell group; and means for based on the value of the beam failure instance counter associated with the primary secondary cell being equal to or exceeding the threshold value upon activation of the secondary cell group, determining the beam failure is detected on the primary secondary cell in the secondary cell group.

In some example embodiments, the first apparatus further comprises means for receiving an indication of activation of the secondary cell group; and means for determining whether a beam failure is detected on the primary secondary cell in the secondary cell group upon receipt of the indication.

In some example embodiments, the at least one contention free resource is configured via a radio resource control message.

In some example embodiments, the first apparatus further comprises means for based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group, determining whether a beam failure recovery timer is configured for the first apparatus; and means for based on determining that the beam failure recovery timer is configured for the first apparatus, starting the beam failure recovery timer.

In some example embodiments, the beam failure recovery timer is started upon the activation of the secondary cell group.

In some example embodiments, the beam failure recovery timer is started upon initiation of the random access procedure.

In some example embodiments, the first apparatus further comprises: means for transmitting, to a network device providing the secondary cell group, a random access request for the random access procedure; and means for receive, from the network device, a random access response.

In some example embodiments, the first apparatus is a terminal device.

In some example embodiments, an apparatus, also referred to as a third apparatus, capable of performing any of the method 400 (for example, the second third 130 in FIG. 1) may comprise means for performing the respective operations 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. The third apparatus may be implemented as or included in the third apparatus 130 in FIG. 1.

In some example embodiments, the third apparatus comprises means for receiving, from a terminal device, a random access request for a random access procedure in a secondary cell group configured for the terminal device, wherein the random access procedure is to be performed based on a need to activate the secondary cell group by utilizing at least one contention free resource for beam failure recovery; and means for transmitting, to the terminal device, a random access response.

In some example embodiments, the at least one contention free resource is configured by the third apparatus.

In some example embodiments, the third apparatus is a network device.

FIG. 5 is a simplified block diagram of a device 500 that is suitable for implementing example embodiments of the present disclosure. The device 500 may be provided to implement a communication device, for example, the first apparatus 110 or the second apparatus 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 one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 540 may include at least one antenna.

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) , an optical disk, a laser disk, 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 instructions of the program 530 may include instructions for performing operations/acts of some example embodiments of the present disclosure. The program 530 may be stored in the memory, e.g., the ROM 524. The processor 510 may perform any suitable actions and processing by loading the program 530 into the RAM 522.

The example 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 FIG. 2 to FIG. 4. The example 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. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. 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) .

FIG. 6 shows an example of the computer readable medium 600 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 600 has the program 530 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although 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.

Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. 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. The program code 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 code, 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 code 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.

Further, although 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, although 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. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of 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

An apparatus comprising:

at least one processor; and

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

determine that a beam failure is detected on a primary secondary cell in a secondary cell group configured for the apparatus upon activation of the secondary cell group;

determine that at least one contention free resource for beam failure recovery is configured for the apparatus; and

based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group and the at least one contention free resource for beam failure recovery being configured for the apparatus, utilize the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the secondary cell group.
The apparatus of claim 1, wherein the apparatus is further caused to:

determine whether a value of a beam failure instance counter associated with the primary secondary cell is equal to or exceeds a threshold value upon activation of the secondary cell group; and

based on the value of the beam failure instance counter associated with the primary secondary cellbeing equal to or exceeding the threshold value upon activation of the secondary cell group, determine the beam failure is detected on the primary secondary cell in the secondary cell group.
The apparatus of claim 1, wherein the apparatus is further caused to:

receive an indication of activation of the secondary cell group; and

determine whether a beam failure is detected on the primary secondary cell in the secondary cell group upon receipt of the indication.
The apparatus of claim 1, wherein the at least one contention free resource is configured via a radio resource control message.
The apparatus of claim 1, wherein the apparatus is further caused to:

based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group, determine whether a beam failure recovery timer is configured for the apparatus; and

based on determining that the beam failure recovery timer is configured for the apparatus, start the beam failure recovery timer.
The apparatus of claim 5, wherein the beam failure recovery timer is started upon the activation of the secondary cell group.
The apparatus of claim 5, wherein the beam failure recovery timer is started upon initiation of the random access procedure.
The apparatus of claim 1, wherein the apparatus is further caused to:

transmit, to a network device providing the secondary cell group, a random access request for the random access procedure; and

receive, from the network device, a random access response.
The apparatus of any of claims 1-8, wherein the apparatus is a terminal device.
An apparatus comprising:

at least one processor; and

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

receive, from a terminal device, a random access request for a random access procedure in a secondary cell group configured for the terminal device, wherein the random access procedure is to be performed based on a need to activate the secondary cell group by utilizing at least one contention free resource for beam failure recovery; and

transmit, to the terminal device, a random access response.
The apparatus of claim 10, wherein the at least one contention free resource is configured by the apparatus.
The apparatus of claim 10, wherein the apparatus is a network device.
A method comprising:

determining, at an apparatus, that a beam failure is detected on a primary secondary cell in a secondary cell group configured for the apparatus upon activation of the secondary cell group;

determining that at least one contention free resource for beam failure recovery is configured for the apparatus; and

based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group and the at least one contention free resource for beam failure recovery being configured for the apparatus, utilizing the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the secondary cell group.
A method comprising:

receiving, at an apparatus and from a terminal device, a random access request for a random access procedure in a secondary cell group configured for the terminal device, wherein the random access procedure is to be performed based on a need to activate the secondary cell group by utilizing at least one contention free resource for beam failure recovery; and

transmitting, to the terminal device, a random access response.
An apparatus comprising:

means for determining that a beam failure is detected on a primary secondary cell in a secondary cell group configured for the apparatus upon activation of the secondary cell group;

means for determining that at least one contention free resource for beam failure recovery is configured for the apparatus; and

means for based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group and the at least one contention free resource for beam failure recovery being configured for the apparatus, utilizing the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the secondary cell group.
An apparatus comprising:

means for receiving, from a terminal device, a random access request for a random access procedure in a secondary cell group configured for the terminal device, wherein the random access procedure is to be performed based on a need to activate the secondary cell group by utilizing at least one contention free resource for beam failure recovery; and

means for transmitting, to the terminal device, a random access response.
A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to:

determine that a beam failure is detected on a primary secondary cell in a secondary cell group configured for the apparatus upon activation of the secondary cell group;

determine that at least one contention free resource for beam failure recovery is configured for the apparatus; and

based on the beam failure being detected on the primary secondary cell in the secondary cell group upon activation of the secondary cell group and the at least one contention free resource for beam failure recovery being configured for the apparatus, utilize the at least one contention free resource for beam failure recovery for a random access procedure that is performed based on a need to activate the secondary cell group.
A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to:

receive, from a terminal device, a random access request for a random access procedure in a secondary cell group configured for the terminal device, wherein the random access procedure is to be performed based on a need to activate the secondary cell group by utilizing at least one contention free resource for beam failure recovery; and

transmit, to the terminal device, a random access response.