CN116458256A

CN116458256A - Method and system for UE actions upon SCG activation and deactivation

Info

Publication number: CN116458256A
Application number: CN202180072403.5A
Authority: CN
Inventors: J·M·马塔姆; V·K·什里瓦斯塔瓦; F·A·拉蒂夫
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2020-10-22
Filing date: 2021-10-21
Publication date: 2023-07-18

Abstract

The present disclosure relates to a communication method and system for fusing a fifth generation (5G) communication system supporting higher data rates than a fourth generation (4G) system with internet of things (IoT) technology. The present disclosure may be applied to smart services based on 5G communication technology and IoT-related technology, such as smart home, smart building, smart city, smart car, networking car, healthcare, digital education, smart retail, security and security services. The present disclosure provides a method for enabling User Equipment (UE) actions upon Secondary Cell Group (SCG) deactivation.

Description

Method and system for UE actions upon SCG activation and deactivation

Technical Field

The present disclosure relates to actions performed by a User Equipment (UE). More specifically, the present disclosure relates to at least one action performed by a UE with respect to Secondary Cell Group (SCG) activation and deactivation.

Background

In order to meet the increasing demand for wireless data services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or front 5G communication systems. Thus, a 5G or front 5G communication system is also referred to as a 'beyond 4G network' or a 'LTE-after-system'. A 5G communication system is considered to be implemented in a higher frequency (millimeter wave) band (e.g., 60GHz band) in order to achieve higher data rates. In order to reduce propagation loss of radio waves and increase transmission distance, beamforming, massive Multiple Input Multiple Output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, massive antenna techniques are discussed in 5G communication systems. Further, in the 5G communication system, development of system network improvement is underway based on advanced small cells, cloud Radio Access Networks (RANs), ultra dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, cooperative multipoint (CoMP), reception-side interference cancellation, and the like. In 5G systems, hybrid FSK and QAM modulation (FQAM) and Sliding Window Superposition Coding (SWSC) have been developed as Advanced Code Modulation (ACM), as well as Filter Bank Multicarrier (FBMC), non-orthogonal multiple access (NOMA) and Sparse Code Multiple Access (SCMA) as advanced access technologies.

The internet is an artificially-centric connected network in which humans generate and consume information, and is now evolving towards the internet of things (IoT) in which distributed entities, such as things, exchange and process information without human intervention. Through connection with cloud servers, internet of everything (IoE) has emerged that combines IoT technology with big data processing technology. As a technical element required for IoT realization: such as "sensing technology", "wired/wireless communication and network infrastructure", "service interface technology" and "security technology", sensor networks, machine-to-machine (M2M) communication, machine Type Communication (MTC), etc. have been recently studied. Such IoT environments may provide intelligent internet technology services that create new value for human life by collecting and analyzing data generated between the interconnects. With the convergence and integration between existing Information Technology (IT) and various industrial applications, ioT may be applied in a variety of fields including smart homes, smart buildings, smart cities, smart cars or networked cars, smart grids, healthcare, smart appliances, and advanced medical services.

In response to this, various attempts have been made to apply 5G communication systems to IoT networks. For example, techniques such as sensor networks, machine Type Communications (MTC), and machine-to-machine (M2M) communications may be implemented by beamforming, MIMO, and array antennas. The application of cloud Radio Access Networks (RANs) as the big data processing technology described above may also be considered as an example of a convergence between 5G technology and IoT technology.

In general, there are use cases and applications that can benefit from quickly establishing dual connectivity on a UE. For this reason, it is reasonable for the Network (NW) operator to configure the SCG for the UE as early as possible in the connection (configure dual connectivity to the UE) (e.g., once the connection is established, or once the UE is in the coverage of the SCG, etc.). It is also possible that the UE no longer needs dual connectivity for its ongoing services and may get better service without dual connectivity. One approach is that if SCG is no longer needed, the UE may release from the dual connection and revert to the single connection.

It is important to clearly specify UE behavior upon activation and deactivation of SCGs.

In the current specification, PDCP restoration is performed upon handover from a split bearer to a normal bearer, i.e., upon release of one of the RLC entities associated with the Packet Data Convergence Protocol (PDCP) of the split bearer. When such an event occurs (e.g., when one RLC of the split bearer is released), the network configures PDCP restoration to the UE. During PDCP recovery, the associated RLC entity is always released (i.e., no RLC suspension). Therefore, there is no UE autonomous trigger to perform restoration of PDCP in the prior art.

If the condition(s) PSCell change (CPC) candidate is (are) configured while the SCG is in a deactivated/suspended state, and if the condition for executing CPC is satisfied, there is no suitable method in the prior art to deal with this situation.

In the prior art, when the SCG is in a deactivated/suspended state, if any Master Cell Group (MCG) failure is detected, the UE will not be able to send mcgfailurenformation to the NW.

According to the current specification (TS 38.331), measurement reports are sent through signaling radio bearer 3 (SRB 3) if NR is configured as SCG in a multi-radio dual connectivity (MR-DC) scenario, i.e. (NG) EN-DC, NR-DC, and triggered for configuration associated with SCG, if SRB3 is being configured on the UE. In an alternative scenario, if SRB3 is not configured on the UE, the measurement report is sent through ulinfomationtransfermrdc on the MCG (i.e. through SRB1 of the MCG).

When SCG deactivation is supported, this creates a new state for SRB3, where SRB3 is configured but SCG has been deactivated. In this case:

ALT1: isolation of SRB3

Any trigger measurement report of the configuration associated with the SCG may be sent through the MCG leg of SRB 3.

ALT2: conventional SRB3, i.e. non-isolated SRB3

SRB3 is in an abort state and therefore cannot be used to send measurement reports. This is a major problem when SRB3 is in the normal state.

The primary SCG cell (PSCell) may become very poor if the SCG is deactivated, which may lead to some failure (RACH or synchronization failure) if the NW sends a reactivation of the SCG. The UE will trigger a RACH (random access channel) procedure and will declare RACH failure after expiration of the T304 timer. This will trigger SCG failure.

As described above, various procedures need to be defined for various UE actions upon activation and deactivation of SCG.

The above information is presented merely as background information to aid in the understanding of the present disclosure. No determination is made, nor is an assertion made, as to whether any of the above may be applied to the present disclosure as prior art.

Disclosure of Invention

Technical problem

Aspects of the present disclosure address at least the problems and/or disadvantages described above and provide at least the advantages described below. Accordingly, one aspect of the present disclosure is to introduce a selection of concepts in a simplified form that are further described below in the detailed description of the present disclosure. This summary is not intended to identify key or essential inventive concepts of the disclosure, nor is it intended to be used to determine the scope of the disclosure.

Additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the presented embodiments.

Technical proposal

According to one aspect of the disclosure, the present subject matter relates to providing a method for operating a User Equipment (UE) action upon Secondary Cell Group (SCG) deactivation. The method includes determining a deactivation of an SCG in which the UE is operating. Thereafter, based on determining the deactivation of the SCG, one of a first set of UE actions, a second set of UE actions, and a third set of UE actions is performed. The first set of UE actions is for Signaling Radio Bearers (SRBs). The first set of UE actions includes one of: a) determining that SRB3 is established between the UE and at least one network node of the plurality of network nodes, b) suspending SRB3 established between the UE and the at least one network node based on the determining that SRB3 is established between the UE and the at least one network node, and c) suspending transmission and reception of the split SRB on the SCG. The second set of UE actions is for a Data Radio Bearer (DRB). The second set of UE actions includes one of: a) suspending transmission and reception of DRBs on SCGs, b) suspending transmission of Sounding Reference Signals (SRS) on primary secondary cells (pscells), and c) resetting Medium Access Control (MAC) associated with SCGs. The third set of UE actions is for a multicast broadcast service radio bearer (MRB). The third set of UE actions includes: a) when the UE receives a multicast service on the SCG via the MRB, the MRB is suspended or released, b) the reception of broadcast services on the SCG via the MRB is continued, or c) the MBS-specific MAC of the SCG is maintained.

According to another aspect of the disclosure, the present subject matter relates to providing a method for operating a UE action upon SCG activation (i.e., SCG activation after configuration of SCG) or reactivation (i.e., SCG activation after deactivation of SCG). In this disclosure, the terms SCG activation and reactivation of SCG have been used interchangeably. The method includes performing one of a first set of UE actions and a second set of UE actions based on a determination of reactivation of the SCG. The first set of UE actions is for SRBs, wherein the first set of UE actions includes at least one of: a) determining whether SRB3 is established and suspended between the UE and at least one of the plurality of network nodes, b) resuming SRB3 based on determining that SRB3 is established between the UE and the at least one network node, c) resuming transmission and reception of separate SRBs on the SCG, d) resuming transmission and reception of DRBs on the SCG, and e) resuming transmission of SRS on the PSCell. The second set of UE actions is for MRB. The second set of UE actions includes at least one of: a) When the UE is receiving multicast service on the SCG via the MRB before deactivation, resuming the multicast service reception on the SCG, and b) continuing the reception of broadcast service on the SCG via the MRB.

Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.

Drawings

The foregoing and other aspects, features, and advantages of certain embodiments of the present disclosure will become more apparent from the following description, taken in conjunction with the accompanying drawings, in which:

fig. 1 illustrates a network environment for Dual Connectivity (DC) between a primary cell group (MCG) and a Secondary Cell Group (SCG) according to an embodiment of the present disclosure;

fig. 2 illustrates a diagram of a network node according to an embodiment of the present disclosure;

fig. 3 shows a configuration diagram of a User Equipment (UE) in a wireless communication system according to an embodiment of the present disclosure;

fig. 4 illustrates a flowchart for enabling UE actions upon SCG deactivation and reactivation according to an embodiment of the present disclosure;

fig. 5 shows a flowchart for enabling UE actions upon SCG deactivation, according to an embodiment of the present disclosure;

fig. 6 shows an operational flow diagram depicting a method of configuring CHO for a PSCell according to an embodiment of the disclosure;

fig. 7 illustrates an operational flow diagram when an MCG failure is detected, according to an embodiment of the present disclosure; and

fig. 8 illustrates a flowchart for enabling UE actions upon SCG activation or reactivation according to an embodiment of the disclosure.

Throughout the drawings, it should be noted that the same reference numerals are used to describe the same or similar elements, features and structures.

Detailed Description

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to aid understanding, but these are to be considered exemplary only. Accordingly, one of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to literature meanings, but are used only by the inventors to enable clear and consistent understanding of the present disclosure. Accordingly, it will be apparent to those skilled in the art that the following descriptions of the various embodiments of the present disclosure are provided for illustration only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

It should be understood that the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more such surfaces.

The term "some" as used herein is defined as "none, or one, or more than one, or all". Thus, the terms "none," "one," "more," "one more," but not all "or" all "are defined as" some. The term "some embodiments" may refer to no embodiment or one embodiment or several embodiments or all embodiments. Thus, the term "some embodiments" is defined to mean "no embodiment, or one embodiment, or more than one embodiment, or all embodiments.

The terms and structures used herein are used for the purpose of describing, teaching and setting forth some embodiments and their specific features and elements, and are not intended to limit, restrict or narrow the spirit and scope of the claims or their equivalents.

More specifically, any term used herein: such as, but not limited to, "comprising," "including," "having," "composing," and grammatical variants thereof, do not specify the exact limits or constraints, and certainly do not preclude the possible addition of one or more features or elements, unless otherwise specified, and furthermore, they are not intended to exclude the possible removal of one or more of the listed features and elements, unless otherwise specified by the limiting language "must include" or "need to include".

Whether a feature or element is limited to use only once, it may be referred to as "one or more features" or "one or more elements" or "at least one feature" or "at least one element" in any event. Furthermore, the use of the term "one or more" or "at least one" feature or element does not exclude the absence of such feature or element unless otherwise specified by a limiting language such as "one or more is required or" requires one or more elements ".

Unless otherwise defined, all terms used herein, particularly any technical and/or scientific terms, may be considered to have the same meaning as commonly understood by one of ordinary skill in the art

For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as illustrated therein being contemplated as would normally occur to one skilled in the art to which the disclosure relates. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The systems, methods, and examples provided herein are illustrative only and not limiting.

Embodiments of the present disclosure will be described below with reference to the accompanying drawings.

Fig. 1 illustrates a network environment 100 for Dual Connectivity (DC) between a primary cell group (MCG) 103 and a Secondary Cell Group (SCG) 101, according to an embodiment of the present disclosure.

Referring to FIG. 1, it can be seen that one or more UEs 107 are typically connected to one or more Network Nodes (NNs) 105. That is, one UE 107 may be connected with one NN 105 as shown in FIG. 1. The network node may be an eNB or a gNB or any network node belonging to the upcoming wireless standard of the next generation. For example, one or more network nodes are connected to a Core Network (CN).

As an example, the network environment 100 may be a Long Term Evolution (LTE) system commonly referred to as 4G according to 3GPP or a New Radio (NR) as in 5G or a future 6G wireless network. The network environment 100 may include a Radio Access Network (RAN), a core network, and the like.

Fig. 2 illustrates a diagram of a network node according to an embodiment of the present disclosure.

Referring to fig. 2, the network node 105 may include at least one processor 201, a memory unit 203 (e.g., a storage), a communication unit 205 (e.g., a communicator or a communication interface), and an activation/deactivation controller 207. Furthermore, the network node 105 may also comprise a cloud RAN (C-RAN), a Central Unit (CU), a Core Network (CN), a Distributed Unit (DU) or any other possible Network (NW) entity. Various examples of network nodes are explained above and are therefore omitted here for brevity. The communication unit 205 may perform a function of transmitting and receiving signals via a wired or wireless channel.

In an example, the processor 201 and the activation/deactivation controller 207 may be a single processing unit or a number of units, all of which may include multiple computing units. The processor 201 and activation/deactivation controller 207 may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions. The processor 201 and activation/deactivation controller 207 may be configured to, among other capabilities, retrieve and execute computer-readable instructions and data stored in memory. The processor 201 and the activation/deactivation controller 207 may include one or more processors. At this time, the one or more processors may be general-purpose processors such as a Central Processing Unit (CPU), an Application Processor (AP), etc., graphics-specific processing units such as a Graphics Processing Unit (GPU), a Visual Processing Unit (VPU), and/or AI-specific processors such as a Neural Processing Unit (NPU). The one or more processors control the processing of the input data according to predefined operating rules or Artificial Intelligence (AI) models stored in the non-volatile memory and the volatile memory. Predefined operational rules or artificial intelligence models are provided through training or learning.

Memory unit 203 may include any non-transitory computer-readable medium known in the art including, for example, volatile memory (such as Static Random Access Memory (SRAM) and Dynamic Random Access Memory (DRAM)), and/or non-volatile memory (such as Read Only Memory (ROM), erasable programmable ROM, flash memory, hard disk, optical disk, and magnetic tape).

Fig. 3 shows a configuration diagram of a UE 107 in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 3, the configuration may be understood as part of the configuration of the UE 107. In the following, it should be understood that the term comprising "unit" or "module" at the end may refer to a unit for processing at least one function or operation, and may be implemented in hardware, software or a combination of hardware and software.

Referring to fig. 3, the ue 107 may include at least one processor 301, a communication unit 303 (e.g., a communicator or a communication interface), a storage unit or memory unit 305, and an activation/deactivation controller 307. For example, the UE 107 may be a cellular telephone, ioT device, vehicle device with communication facilities, television with connectivity, laptop computer, or other device that communicates over multiple cellular networks (such as 3G, 4G, 5G, or 6G networks or any future wireless communication network).

In addition, the memory unit 305 and the activation/deactivation unit 307 have been explained above, and thus the same contents are omitted here for the sake of brevity. The communication unit 303 may perform a function of transmitting and receiving signals via a wireless channel.

Fig. 4 shows a flowchart for enabling UE actions upon SCG deactivation and activation (reactivation) according to an embodiment of the present disclosure.

Referring to FIG. 4, the method 400 may be performed at the UE 107.

Fig. 4 will be explained with reference to fig. 1 to 3. In embodiments of the present disclosure, when configured as a dual connection (mcg+scg) in connected mode, the UE 107 may perform the following actions.

Initially, the UE 107 is configured as a dual connection (mcg+scg) in a connected mode at operation 401. Thereafter, the UE 107 may receive an activation request for a deactivated SCG at operation 403, or the UE 107 may receive a deactivation request for an activated SCG at operation 405. Further, depending on the receipt of activation or deactivation, at operation 407, the UE 107 performs a set of UE actions as proposed at the time of activation/deactivation or a combination thereof. The set of UE actions performed by the UE 107 will be described in the following paragraphs.

Fig. 5 shows a flowchart for enabling UE actions upon SCG deactivation, according to an embodiment of the present disclosure.

Referring to fig. 5, explanation will be made with reference to fig. 1-4, wherein the method 500 may be performed at the UE 107. In an embodiment, upon deactivation of the SCG, the UE 107 will perform the following actions:

in operation 501-A: the method 500 includes determining deactivation of a Secondary Cell Group (SCG) in which the UE is operating. Based on the determination of the deactivation of the Secondary Cell Group (SCG), the UE performs one or more UE actions at operation 501-B.

In operation 501: the set of UE actions is for Signaling Radio Bearers (SRBs). Alternatively, the set of UE actions for SRBs may be referred to as a first set of UE actions. According to an embodiment of the present disclosure, the first set of UE actions includes operations 503-507, which may correspond to operation 407 of fig. 4. According to an embodiment of the present disclosure, the first set of UE actions includes operations 503-507 and may correspond to operation 407 of fig. 4. The second set of UE actions includes operations 511-514 and may correspond to operation 407 of fig. 4. The third set of UE actions includes operations 517-21 and may correspond to operation 407 of fig. 4.

Thus, at operation 503, it is determined whether SRB3 is established between the UE 107 and at least one of the plurality of network nodes. Whether SRB3 is established.

At operation 505, the UE 107 aborts the SRB3 established between the UE 107 and the at least one network node 105 based on determining that the SRB3 is established between the UE 107 and the at least one network node 105.

At operation 507, the method 500 includes suspending transmission and reception of the split SRB over the SCG. Operations 503-507 are associated with a first set of UE actions, wherein the UE 107 performs at least one step of the first set of UE actions.

At operation 509, the method 500 further comprises performing another set of UE actions for a Data Radio Bearer (DRB). Another set of UE actions includes one of the following:

at operation 511, the method 500 includes suspending transmission and reception of DRBs on the SCG. Further, uplink data processing may not be disabled during SCG deactivation (e.g., for Acknowledged Mode (AM) DRB, even if transmission is suspended during SCG deactivation). In an embodiment of the present disclosure, the ue 107 suspends transmission of Sounding Reference Signals (SRS) on the PSCell at operation 513. At operation 514, the UE 107 performs a reset of a Media Access Control (MAC) associated with the SCG. In an alternative, a Time Alignment (TA) timer is maintained after SCG deactivation and SCG MAC is not reset.

Further, alternatively, the set of UE actions for DRBs may be referred to as a second set of UE actions. Operations 511-514 may correspond to operation 407 of fig. 4, according to an embodiment of the disclosure.

At operation 515, the method 500 further includes performing another set of UE actions for a multicast and broadcast service radio bearer (MRB). Another set of UE actions includes one of the following:

at operation 517, the UE 107 aborts or releases the MRB when the UE is receiving multicast services on the SCG via the MRB. Operation 517 may comprise suspending or releasing at least one associated MRB configuration of the multicast service, flushing HARQ (hybrid automatic repeat request) buffers, resetting timers, etc. In operation 519, the UE 107 continues to perform reception of broadcast services over the SCG via the MRB. In operation 521, the UE 107 maintains the MBS-specific MAC of the SCG. This means that at least one associated MRB configuration, HARQ buffer, timer of the broadcast service is maintained.

Further, alternatively, the set of UE actions for MRB may be referred to as a third set of UE actions. Operations 517-521 may correspond to operation 407 of fig. 4, according to an embodiment of the disclosure.

In an embodiment of the present disclosure, upon SCG deactivation, the UE 107 will follow the actions as shown in fig. 5:

for SRB:

SRB3 is aborted (if established). In an alternative approach, SRB3 does not abort, but no transmission or reception is performed for SRB 3.

The transmission and reception of the split SRB over the SCG is aborted.

For DRB:

the general actions are as follows:

the transmission and reception of DRBs on SCG is suspended. Further, uplink data processing may not be disabled during SCG deactivation (e.g., for Acknowledged Mode (AM) DRB, even if transmission is suspended during SCG deactivation).

Suspending SRS transmission on the PSCell;

reset SCG MAC. In an alternative approach, the TA timer associated with the SCG or PSCell continues to run when the SCG is deactivated. In this case, the SCG MAC is not reset.

For MRB:

if the UE is receiving MRB for the multicast service on the SCG, the MRB is aborted and/or released. The operations may include suspending or releasing at least one associated MRB configuration of the multicast service, flushing the HARQ buffer, resetting a timer, etc.

If the UE is receiving an MRB of the broadcast service on the SCG, reception of the MRB for the broadcast service is continued.

The MBS-specific MAC of the SCG is maintained, i.e., MBS-specific reset is not performed for the SCG MAC. This means that at least one associated MRB configuration, HARQ buffer, timer of the broadcast service is maintained.

According to an embodiment of the present disclosure, method 1 includes:

the configuration(s) associated with the SCG received in the varconditional reconfig continue to be evaluated.

The configuration(s) associated with the SCG received in measConfig continue to be evaluated.

Suspend other Config associated with SCG (if configured)

Timers T346a, T346b, T346c, T346d, and T346e associated with SCG are stopped (if running).

The bap-Config associated with the SCG is aborted (if configured).

The iab-IP-address configuration list associated with the SCG is aborted (if configured).

According to another embodiment of the present disclosure, SRB3 and DRB are not suspended, however, uplink transmission or downlink reception is not performed during the time when SCG remains deactivated. This means that the UE can perform uplink data processing (e.g., for AM DRBs).

In accordance with an embodiment of the present disclosure, an alternative to method 1 is disclosed in method 2. The method 2 comprises the following steps:

the configuration(s) associated with the SCG received in the varconditional reconfig are released.

The configuration(s) associated with the SCG received in measConfig are released.

The otherConfig associated with the SCG (if configured) is released.

The bap-Config associated with the SCG is released (if configured).

The iab-IP-address configuration list associated with the SCG (if configured) is released.

According to an embodiment of the present disclosure, for the PDCP entity, the second set of UE actions includes: for the PDCP layer of a Packet Data Convergence Protocol (PDCP) entity, a primary uplink path is changed to a primary cell group (MCG) for a separate DRB. In particular, for a separate DRB, the method 500 includes changing the primary uplink path to the MCG entity (i.e., for the bearer originally configured with the primary uplink path on the SCG).

According to an embodiment of the present disclosure, the second set of UE actions further includes one of suspending PDCP. In an embodiment of the present disclosure, ALT1 comprises: when the SCG is deactivated, one or more PDCP entities associated with the SCG are suspended.

In accordance with an embodiment of the present disclosure, for suspending PDCP, the second set of UE actions includes setting a state variable to an initial value for the transmitting entity and discarding each previously stored PDCP Protocol Data Unit (PDU) for the transmitting entity. As an example, the state variable corresponds to tx_next of the PDCP entity according to the 3GPP specifications.

In an example, for a transmitting PDCP entity:

setting TX_NEXT to an initial value; and

all stored PDCP PDUs are discarded.

Now, based on determining that a reordering timer for the receiving PDCP entity is running, the method 500 further includes stopping and resetting the reordering timer for the receiving entity, and then delivering each previously stored PDCP Service Data Unit (SDU) to a higher layer in ascending order of an associated count value for the receiving entity after the performing of header decompression. Thereafter, the state variable is set to an initial value. As an example, the Reordering timer corresponds to t-Reordering and the state variables correspond to rx_next and rx_deliv.

In an example, for a receiving entity, if t-Reordering is running:

stopping and resetting t-Reordering;

after performing header decompression, delivering all stored PDCP SDUs to higher layers in ascending order of associated COUNT values; and

RX_NEXT and RX_DELIV are set to initial values.

According to another embodiment of the present disclosure, the second set of UE actions further includes PDCP continuing and restoring DRBs configured with keyToUse set as secondary for changing the primary uplink path to the MCG RLC entity.

In an embodiment of the present disclosure, ALT2 comprises: the PDCP is not suspended, and recovery of PDCP configured with DRBs set as secondary keyToUse is not performed.

According to another embodiment of the present disclosure, for PDCP recovering DRBs, the second set of UE actions further includes transmitting a PDCP status report of an Acknowledgement Mode (AM) DRB configured by a higher layer in uplink communication, and then retransmitting all PDCP data PDUs previously delivered to the suspended AM RLC entity for the AM DRB in ascending order of an associated count value, wherein the lower layer does not acknowledge successful delivery.

In an example, for an AM DRB configured by a higher layer to send PDCP status reports in the uplink, the receiving PDCP entity will trigger PDCP status reports. Further, for AM DRBs, the transmitting PDCP entity will perform retransmission of all PDCP data PDUs previously submitted to the suspended AM RLC entity or entities in ascending order of the associated COUNT value, where the lower layer acknowledges that successful delivery has not yet been acknowledged. Furthermore, embodiments will be explained with respect to RLC entities and related UE actions upon deactivation of SCG.

According to another embodiment of the present disclosure, the second set of UE actions further comprises an RLC entity suspending DRBs configured on the SCG. In an example, the method 500 further includes suspending RLC entities of DRBs configured on the SCG. For example, for RLC bearers associated with a radio bearer for which keyToUse is set as secondary.

According to another embodiment of the present disclosure, for an RLC entity suspending a DRB configured on the SCG, the second set of UE actions further includes one of resetting each state variable associated with the RLC entity and storing a current value of the state variable associated with the RLC entity.

In the implementation as ALT 1: all state variables on the RLC are reset. In a further implementation as ALT 2: the current value of the state variable is stored upon deactivation and restored from the current value of the state variable upon reactivation.

According to another embodiment of the present disclosure, the method 500 further includes stopping a plurality of timers for Radio Link Monitoring (RLM) upon deactivation of the SCG based on a determination of an operational status of the plurality of timers configured on the SCG. As an example, the plurality of stop timers are at least one of T304, T310, T312 defined in the 3GPP specifications.

In an implementation, RLM: the timers T310, T312 on the SCG are stopped (if running), and the timer T304 on the SCG is stopped (if running).

In an embodiment of the present disclosure, upon SCG deactivation, the UE continues to monitor Radio Link Monitoring (RLM) in at least one cell in the SCG using the existing configuration for RLM prior to SCG deactivation. In another embodiment of the present disclosure, upon deactivation of the SCG, the UE continues to monitor for RLM in at least one cell in the SCG with the new configuration for RLM. The new configuration for RLM is received together with SCG deactivation, e.g. by RRC reconfiguration, rrcreseume message carrying CellGroupConfig. Alternatively, the gNB only indicates in CellGroupConfig to continue RLM using the existing configuration prior to SCG deactivation, and no new RLM configuration is provided, or RLM is not performed.

Further embodiments will be explained for MAC entities and related UE actions. In particular, UE actions in the case of configuring BeamFailureRecoveryConfig, beamFailureRecoverySCellConfig and radiolinkmotoringconfig for the beam failure detection and recovery procedure for SCG will be explained.

In accordance with an embodiment of the present disclosure, method 500 further includes performing another set of UE actions for a Medium Access Control (MAC) entity. Further, alternatively, another set of UE actions for a MAC entity may be referred to as a fourth set of UE actions. Another set of UE actions includes one of the following:

continuing to monitor detection of beam failure in cells in the SCG; and triggering a Beam Failure Recovery (BFR) procedure based on detection of a beam failure associated with a secondary cell (SCell), or initiating a Random Access Channel (RACH) procedure based on detection of a beam failure associated with a primary secondary cell (PSCell); and

the MAC configuration is suspended and detection of beam failure in the cell in the monitoring SCG is stopped.

In an embodiment of the present disclosure, upon SCG deactivation, the network entity indicates to the UE whether to continue or stop monitoring of at least one of RLM and BFD. This may be indicated along with the SCG deactivation message. When indicated and no new configuration is provided for at least one of RLM and BFD, the UE continues at least one of RLC and BFD with the existing configuration of RLM and BFD after SCG deactivation (i.e., the configuration applicable prior to SCG deactivation).

In the example of ALT 1: the UE should continue monitoring beam failure detection in at least one cell in the SCG. Upon detection of beam failure, BFR is triggered if SCell, or RACH procedure is initiated if PSCell. In another example as ALT 2: the UE should suspend these configurations and stop monitoring beam failure detection.

Further, another set of UE actions for a Medium Access Control (MAC) entity may alternatively be referred to as a fourth set of UE actions. Another set of UE actions for a Medium Access Control (MAC) entity may correspond to operation 407 of fig. 4, according to an embodiment of the disclosure.

In embodiments of the present disclosure, upon SCG deactivation, the UE continues to monitor beam failure detection in at least one cell in the SCG using the existing configuration for BFD prior to SCG deactivation. In another embodiment of the present disclosure, upon SCG deactivation, the UE performs monitoring beam failure detection in at least one cell in the SCG with a new configuration for BFD. The new configuration for BFD is received together with SCG deactivation, e.g. by RRC reconfiguration, rrcreseume message carrying CellGroupConfig. Instead, the gNB only indicates in CellGroupConfig that BFD is continued with the existing configuration prior to SCG deactivation, and no new BFD configuration is provided, or BFD is not performed.

According to another embodiment of the present disclosure, when the UE continues to monitor beam failure in a cell of the SCG and detects beam failure, the UE stops beam failure detection of the SCG and reports the beam failure to the network through the MCG.

According to embodiments of the present disclosure, performing another set of UE actions for a Medium Access Control (MAC) entity includes continuing to run a Time Alignment (TA) timer upon SCG deactivation. For example, when the SCG is deactivated, the TA timer does not stop, but continues with the value of the run timer.

According to another embodiment of the present disclosure, the method 500 further comprises, upon SCG deactivation, performing another set of UE actions for the MAC entity. Another set of UE actions includes at least one of: continuing the TA timer, stopping reporting at least one of a Buffer Status Report (BSR) and a Power Headroom Report (PHR) on the SCG leg, and suspending the Dynamic Power Sharing (DPS) related procedure, and the UE canceling all pending triggers for at least one of the BSR and PHR on the SCG leg, and suspending the DPS related procedure.

Further, upon deactivation of the SCG, another set of UE actions for the MAC entity may correspond to operation 407 of fig. 4. Further, alternatively, another set of UE actions may be referred to as a tenth set of UE actions.

In an embodiment of the present disclosure, if timeAlignmentTimer is running, and if SCG is deactivated, then ALT1: and continuing to run the timeAlignmentTimer. Further, as ALT2: stopping the timeAlignmentTimer.

In an embodiment of the present disclosure, the UE performs at least one of the following actions:

upon deactivation of the SCG, the UE stops reporting BSR and PHR on the SCG leg.

Upon deactivation of the SCG, the UE cancels all pending triggers for BSR and PHR on the SCG leg.

Upon deactivation of the SCG, all Dynamic Power Sharing (DPS) related parameters and procedures are suspended.

In another embodiment of the present disclosure, the method 500 further includes, for mobility configuration, the UE performing a continued evaluation of configured Conditional PSCell Change (CPC) candidates. In an implementation, for mobility: the CPC candidates configured on the UE continue to be evaluated.

In a further implementation, for PDCP: the PDCP entity is maintained upon SCG deactivation.

Furthermore, at the time of SCG deactivation, if the primary UL leg is MCG and there is no UL split, the existing procedure is not changed. Furthermore, if the primary UL leg is MCG and UL split or PDCP duplication is configured, the UE should suspend UL on the Secondary Node (SN). Furthermore, if the primary UL leg is SCG and there is no UL split, the UE may autonomously switch the UL leg to MCG and abort UL on SCG if not explicitly changed by NW. Further, if the primary UL leg is SCG and UL split or PDCP duplication is configured, the UE may autonomously switch the primary UL leg to MCG and abort UL on SN if not explicitly changed by NW.

In accordance with an embodiment of the present disclosure, the method 500 further comprises, upon SCG deactivation, performing another set of UE actions for at least one of Radio Resource Management (RRM) measurements and Channel State Information (CSI) measurements, wherein the other set of UE actions comprises one of:

at least one of RRM measurements and CSI measurements are continued on and/or for at least one cell in the SCG with existing RRC and/or CSI configurations.

At least one of RRM measurements and CSI measurements is continued on at least one cell in the SCG with the newly received RRC and/or CSI configuration while the SCG is deactivated. Upon SCG deactivation, a new configuration is received in the RRC reconfiguration message.

At least one of the RRM configuration and the CSI configuration is suspended and at least one of the RRM measurement and the CSI measurement is stopped from being performed on at least one cell in the SCG.

At least one of the RRM configuration and the CSI configuration is released and at least one of the RRM measurement and the CSI measurement is stopped from being performed on at least one cell in the SCG.

Further, another set of UE actions for at least one of RRM measurements and CSI measurements may correspond to operation 407 of fig. 4. Further, alternatively, another set of UE actions for RRM measurements and CSI measurements may be referred to as an eleventh set of UE actions.

According to yet another embodiment of the present disclosure, the method 500 further comprises performing at least one of RRM measurement and CSI measurement of the SCG cell for at least one of RRM configuration and CSI configuration such that a frequency of the at least one of RRM measurement and CSI measurement is reduced. When the SCG is deactivated, at least one of the RRM configuration and the CSI configuration is received at least one of the plurality of network nodes, and the RRM configuration and the CSI configuration are based on at least one of signal conditions and UE mobility information. Thus, the UE performs RRM measurements and/or CSI measurements on SCG cells in a wide or loose manner.

In embodiments of the present disclosure, the UE is allowed to report CSI reports on and/or for at least one SCG cell upon SCG deactivation, depending on the configuration of the network. The configuration is provided by the network, for example, using RRC signaling when SCG is deactivated.

In embodiments of the present disclosure, the UE performs RRM measurements and/or CSI measurements for the SCG cells in a conventional manner, from an earlier wide or loose manner when the SCG is in a deactivated state to when the SCG is (re) activated. The conventional configuration for measurement is the same as that previously used for deactivation and/or new configuration by the network.

In an embodiment of the present disclosure, the UE relinquishes DRX configuration of the SCG when the SCG is deactivated.

In another embodiment of the present disclosure, the UE maintains the DRX configuration of the SCG, however, when the SCG is deactivated, the UE does not apply the DRX operation of the SCG.

In another embodiment of the present disclosure, when the SCG is deactivated, the UE performs CSI measurement and/or reports CSI reporting during a period corresponding to an On-duration (On-duration) timer of the DRX configuration. Alternatively, the on duration timer may not be started.

In an embodiment of the present disclosure, the UE 107 performs RRM measurements and/or CSI measurements on at least one SCG cell upon SCG activation or reactivation, as follows:

in implementations as ALT1, UE 107 may continue to perform RRM measurements and/or CSI measurements for at least one cell in the SCG.

In implementations as ALT2, UE 107 may resume configuration for RRM and/or CSI that was suspended upon SCG deactivation and initiate/restart performing RRM measurements and/or CSI measurements for at least one cell in the SCG.

In implementations as ALT3, UE 107 may receive the new configuration from the network and, accordingly, begin performing RRM measurements and/or CSI measurements on at least one cell in the SCG.

Upon reactivation, the UE 107 returns to the primary uplink path based on the original configuration from the network. Currently, PDCP recovery occurs only at handover or re-establishment. To facilitate data recovery due to SCG deactivation, the receiving PDCP entity may trigger a PDCP status report when the SCG is deactivated. Upon SCG deactivation, the UE 107 may recover PDCP configured with DRBs set to secondary keyToUse. For AM, the DRB is configured by higher layers to send PDCP status reports in the uplink, which the receiving PDCP entity can trigger. For AM, DRB, the transmitting PDCP entity may perform retransmission of all PDCP data PDUs previously submitted to the suspended AM RLC entity or entities in ascending order of the associated COUNT value, where the lower layer has not yet acknowledged successful delivery.

Upon SCG deactivation, the associated RLC is released or suspended.

In the example of ALT1, the network signals the UE the deactivation of SCG. Now, the network also configures all SCG PDCP using the recovery PDCP, while signaling about SCG deactivation. The UE performs actions at PDCP recovery, i.e., PDCP status report of PDCP Rx entity and PDCP reordering/retransmission of PDCP Tx entity. For AM, higher layer configured DRBs send PDCP status reports in the uplink, and the receiving PDCP entity will trigger PDCP status reports. Furthermore, for AM, DRB, the transmitting PDCP entity will perform retransmission of all PDCP data PDUs previously submitted to the suspended AM RLC entity in ascending order of associated COUNT value, wherein the lower layer has not yet acknowledged successful delivery.

In the example of ALT2, the UE autonomously triggers deactivation of the SCG. In the example of ALT 2A: for network assisted recovery: upon SCG deactivation, the network resumes pre-configuration (during bearer setup or modification) of SCG PDCP with PDCP. For example IE SCGDeactiveRecoverPDCP to allow triggering of PDCP entities upon SCG deactivation.

In the example of ALT 2: the UE autonomously triggers: upon deactivation of the SCG, the UE autonomously triggers PDCP restoration of the required bearer.

Further, when an indication of RLC suspension is received from a higher layer, the UE 107 performs the following actions:

the RLC entity is transmitted. This includes:

buffered data: discard all RLC SDUs, RLC SDU segments, and RLC PDUs (if any);

and (3) a timer: stop and reset all timers; and

a state variable.

In the example of ALT1, UE 107 resets all state variables to their initial values, e.g., TX_Next is set to the initial value. In the example of ALT 2: the UE 107 stores state variables in order to continue them upon reactivation of the SCG. b) The RLC entity is received. This includes:

and (3) a timer: all timers are stopped and reset, e.g., the reassembly timer (if running) is stopped and reset.

Stored data: RLC SDUs are delivered to higher layers in ascending order of SN values.

In the example of ALT1, UE 107 resets all state variables to their initial values, e.g., RX_Next is set to the initial value.

In the example of ALT 2: the UE 107 stores state variables in order to continue them upon reactivation of the SCG.

The 38.322 specification in table 1 below (examples):

TABLE 1

According to another embodiment of the present disclosure, the method 500 further includes determining that the CPC is configured and the associated conditions of the configuration are satisfied during the deactivation of the SCG. Based on determining that the CPC is configured and the associated conditions of the configuration are met, the suspended SRB3 is resumed, the configuration of the target cell is applied, and a Random Access Channel (RACH) procedure is initiated to transmit the complete RRC reconfiguration required upon execution of the CPC. Further, after successful completion of the RACH procedure, the UE returns to a SCG suspended or deactivated state. In an alternative, the UE re-activates the SCG and monitors future de-activations of the SCG based on the configuration received from the plurality of network nodes. In another alternative, the SCG status (active or inactive) is based on signaling from the CPC target node.

In an implementation, while the SCG is in the deactivated/suspended state, if the CPC is configured, and if the associated conditions of the configuration are met, the UE 107 performs the following actions:

and restoring the suspended SRB3.

The UE may apply the configuration of the target cell.

A RACH procedure is initiated to transmit RRC reconfiguration complete required at CPC execution.

After successful completion of the RACH procedure, the UE may

Returning to the SCG suspended state, because the trigger to re-activate the SCG is for mobility; or alternatively

Reactivation of SCG and monitoring for data inactivity (future deactivation of SCG).

In another implementation as alternative 3 (ALT 3), the SCG status (active/inactive) is based on signaling from the CPC target node.

Fig. 6 shows an operational flow diagram 600 depicting a method of configuring CHO for a PSCell according to an embodiment of the disclosure. Accordingly, the UE 107 may perform the following operations:

referring to fig. 6, at operation 603, the network 301 may initiate PDCP configuration that the UE 107 needs to apply when moving to a target cell. Thereafter, at operation 605, at the UE 107, when the CHO criteria are met, the UE 107 has deactivated/suspended the SCG. Thereafter, the UE 107 applies the target cell configuration. The UE 107 then initiates a RACH procedure. Further, in operation 607, the UE 107 completes the RACH procedure. Further, in operation 609, the ue continues to be in an SCG deactivated or suspended state instead of 1. Further, in operation 611, instead of 2, the UE 107 moves to the SCG-active state by default.

Fig. 7 shows an operational flow diagram 700 when an MCG failure is detected, according to an embodiment of the present disclosure.

Referring to fig. 7, a method 700 includes detecting a Master Cell Group (MCG) failure during a time when the SCG is in a deactivated state. Thereafter, another set of UE actions is performed based on the detection of the MCG failure to report the detected MCG failure. Accordingly, another set of UE actions includes one of:

triggering a Random Access Channel (RACH) procedure based on a previously stored configuration of the SCG;

after completion of the RACH procedure, each of the SCG and the suspended SRB3 is activated;

after activation or reactivation, sending MCGFailureInformation associated with the detected MCG failure to a plurality of network nodes; and

triggering a reestablishment procedure associated with a reactivation failure of the SCG.

Further, alternatively, the set of UE actions based on the detection of MCG failure may be referred to as a fifth set of UE actions. The set of UE actions based on the detection of MCG failure may correspond to operation 407 of fig. 4, according to an embodiment of the present disclosure.

Referring to fig. 7, as option 1, in operations 701 and 703, if an MCG failure is detected while the SCG is in a deactivated/suspended state, the UE should trigger a RACH procedure with a previously stored configuration of the SCG. Thus, NW 601 may provide the RACH configuration that needs to be applied with the deactivation command, or UE 107 may use the same RACH configuration shared by NW 601 when configuring/adding SCG.

Further, after successful completion of RACH, NW 601 may activate SCG and SRB3. Thus, the UE 107 may perform the following actions:

after activating SCG through SRB3 or separate SRB1, the UE may send failure information as mcgfailurenformation.

The UE 107 may include and set measResultSCG or measResultSCG-EUTRA, as applicable.

If the UE 107 fails to properly activate the SCG due to any failure, it may trigger a re-establishment procedure.

According to another embodiment as option 2, if an MCG failure is detected while the SCG is in a deactivated/suspended state, the UE may directly trigger the re-establishment procedure as another set of UE actions. For example, if MCG failure is not declared/MCGFailureInformation procedure is not initiated, RLF is declared and a rebuild procedure is initiated.

As another embodiment of the present disclosure, in method 500, the fifth set of UE actions may include at least one of:

when SRB3 is configured and SCG is in an active state, UE 107 performs the delivery of mcgfailurenformation to lower layers via SRB3 for transmission as a message embedded in an NR Radio Resource Control (RRC) message.

When SRB3 is configured and the SCG is deactivated, the UE 107 executes an activated SCG that is used to submit MCGFailureInformation to lower layers.

When SRB1 is configured to split SRB, UE 107 performs a handover of MCGFailureinformation to lower layers for transmission via SRB 1. At the time of delivery of the message, the process ends.

Tables 3 and 4 show methods associated with another set of UE actions when MCG failure is detected.

TABLE 2

TABLE 3 Table 3

TABLE 4 Table 4

According to yet another embodiment of the present disclosure, if the NR is configured as an SCG in an MR-DC scenario (i.e., (NG) EN-DC, NR-DC) and a measurement report is triggered for a configuration associated with the SCG, then a new process must be added. To this end, the method 500 further comprises performing a sixth set of UE actions for transmitting a MeasurementReport message from the UE 107 to the plurality of network nodes. The sixth set of UE actions for transmitting the measurement result includes one of:

when the UE is in one of an EUTRA-NR dual connectivity (EN-DC) mode and a (NG) EN-DC and NR-NR dual connectivity (NR-DC) mode, and SRB3 is configured and SCG is in an active state, submitting a MeasurementReport message to lower layers of the plurality of network nodes via SRB 3; and

when the UE is in EN-DC mode or one of (NG) EN-DC and NR-DC mode and SRB3 is not configured or SCG is in a deactivated state, a MeasurementReport message is submitted via SRB1 as a message embedded in a Radio Resource Control (RRC) message.

In one implementation, the new process is as follows:

if the NR is configured as an SCG in an MR-DC scenario (i.e., (NG) EN-DC, NR-DC), and a measurement report is triggered for a configuration associated with the SCG.

If SRB3 is configured on the UE and SCG is not deactivated, or SRB3 is configured to detach SRB.

The MeasurementReport message is sent via SRB 3.

-otherwise,

the MeasurementReport message is sent via uliformationtransfermrdc on the MCG, i.e. via SRB1 of the MCG.

Table 5 describes the procedure of sending the measurement report. The purpose of this procedure is to transfer the measurement results from the UE to the network. The UE will initiate this process only after successful AS security activation. For the measurement_id where the measurement reporting procedure is triggered, the UE will set the measurement result in the measurement report message as shown in table 5 below.

TABLE 5

In embodiments of the present disclosure, UE assistance information is considered. If the NR is configured as SCG in an MR-DC scenario (i.e., (NG) EN-DC, NR-DC) and the UE assistance information message transmission is triggered, a new process must be added. The purpose of this procedure is for the UE to inform the network:

its delay budget report carries the expected increment/decrement of the connected mode DRX cycle length; or alternatively

Overheat auxiliary information thereof; or alternatively

IDC auxiliary information thereof; or alternatively

Its preference for DRX parameters for power saving; or alternatively

Its preference for maximum aggregate bandwidth for power saving; or alternatively

Its preference for the maximum number of secondary component carriers for power saving; or alternatively

Its preference for the maximum number of MIMO layers for power saving; or alternatively

Its preference for minimum scheduling offset for cross-slot scheduling for power saving; or alternatively

Its preference for RRC state; or alternatively

License assistance information configured for NR side link communication; or alternatively

Its preference is to be provided with reference time information.

According to another implementation, the method 500 further includes performing a seventh set of UE actions for transmitting a UE assysistacinformation message from the UE to the plurality of network nodes. The seventh set of UE actions for transmitting UE assumance information message includes one of:

when the UE is in one of an EUTRA-NR dual connectivity (EN-DC) mode and a (NG) EN-DC and NR-NR dual connectivity (NR-DC) mode, and the SRB3 is configured and the SCG is in an active state, submitting a UE assurelnformation message to lower layers of the plurality of network nodes via the SRB 3; and

when the UE is in one of EN-DC mode and (NG) EN-DC and NR-DC mode and SRB3 is not configured or SCG is in a deactivated state, UE assumability information message is submitted via one of E-UTRAMCG and SRB1 as a message embedded in an E-UTRA Radio Resource Control (RRC) message.

Thus, table 6 provides a new procedure for transmitting a UE assysistanceinformation message from a UE to one or more network nodes.

TABLE 6

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In embodiments of the present disclosure, IAB other information procedures are considered. The IAB-MT uses the IAB other information procedure to request the IAB-donor-CU to assign an IP address or to inform the IAB-donor-CU of the configured IP address of the IAB-DU. If the NR is configured as SCG in an MR-DC scenario (i.e., (NG) EN-DC) and IABOtherInformation message transmission is triggered, then a new process must be added.

According to a further embodiment, the method 500 further comprises performing another set of UE actions for transmitting Integrated Access and Backhaul (IAB) other information messages from the UE to the plurality of network nodes. Another set of UE actions for transmitting IAB other information messages includes one of the following:

when the UE is in one of an EUTRA-NR dual connectivity (EN-DC) mode and a (NG) EN-DC and NR-NR dual connectivity (NR-DC) mode, and SRB3 is configured and SCG is in an active state, submitting an iabotheration message to lower layers of the plurality of network nodes via SRB 3; and

when the UE is in EN-DC mode or one of (NG) EN-DC and NR-DC mode and SRB3 is not configured or SCG is in a deactivated state, the iabotheration message is submitted as a message embedded in an E-UTRA Radio Resource Control (RRC) message via one of E-UTRA MCG and SRB 1.

Alternatively, the set of UE actions for Integrated Access and Backhaul (IAB) transmissions may be referred to as an eighth set of UE actions. The set of UE actions for integrating the transmission of access and backhaul (IAB) may correspond to operation 407 of fig. 4, according to an embodiment of the disclosure.

Thus, table 7 provides a new procedure for transmitting UE assistance information messages from a UE to one or more network nodes.

TABLE 7

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In an embodiment of the present disclosure, consider the FailureInformation process. The UE initiates a procedure when the network needs to be informed of the failure detected by the UE. Specifically, the UE initiates the procedure when the following conditions are met:

upon detection of failure of the RLC bearer.

Upon detection of a DAPS handoff failure.

Upon initiating this process, the UE 107 may perform:

and initiating the transmission of the Failureinformation message.

According to a further implementation, the method 500 further comprises performing another set of UE actions for transmitting, by the UE, a FailureInformation message to the plurality of network nodes. Another set of UE actions for transmitting failure detection information by the UE includes at least one of:

when the failure detection corresponds to one of the MCG RLC bearer and the DAPS failure, a FailureInformation message related to the one of the MCG bearer and the DAPS failure is submitted to a lower layer of the plurality of network nodes via SRB 1.

Submitting a FailureInformation message to lower layers of the plurality of network nodes via SRB3 when SRB3 is configured and SCG is not deactivated and failure detection corresponds to SCG RLC bearer failure;

if the UE is in (NG) EN-DC, SRB3 is not configured or SCG is deactivated, and failure detection corresponds to SCG RLC bearer failure, a FailureInformation message is submitted via E-UTRA SRB1 embedded in E-UTRA RRC message ULInformation transfer MRDC.

If the UE is in NR-DC, SRB3 is not configured and/or SCG is deactivated and failure detection corresponds to SCG RLC bearer failure, the Failureinformation is submitted via SRB1 embedded in NR RRC message ULIFInformatTransferMRDC.

Alternatively, the set of UE actions for transmitting the FailureInformation message may be referred to as a ninth set of UE actions. The set of UE actions for transmitting the FailureInformation message may correspond to operation 407 of fig. 4 according to an embodiment of the present disclosure.

Thus, table 8 provides a new procedure for transmitting a FailureInformation message from a UE to one or more network nodes.

TABLE 8

According to embodiments of the present disclosure, for the scenario where the processing SCG is deactivated and PSCell is very bad, when the NW sends an SCG activation or reactivation request, the UE will trigger RACH and will declare RACH failure after the T304 timer expires, triggering SCG failure.

According to an embodiment of the present disclosure, the UE 107 or one or more network nodes determine a signal strength of an SCG link signal between the UE and at least one of the plurality of network nodes. When the determined signal strength is less than a particular threshold, the UE 107 maintains the SCG in a deactivated state. The particular threshold may be specified or configured or an implementation choice. In another embodiment of the present disclosure, after receipt of the activation or reactivation request, if the UE is unable to activate the PSCell, the UE encounters an SCG failure after the T304 timer expires, and the UE 107 sends a FailureInformation message to at least one of the plurality of network nodes.

In the implementation of process 1: if the signal condition of the SCG link received by the UE is poor. For example, if the signal condition is below a specified and/or configured threshold, the UE may choose not to activate SCG and continue in a deactivated state.

According to procedure 2, if the UE cannot activate PSCell, after expiration of the T304 timer, the UE encounters an SCG failure, the UE may send a FailureInformation message informing it. The UE may use one of the existing failure reasons in the SCG failure information. But it is difficult for the MN to distinguish between a conventional SCG failure and an SCG failure during reactivation. Therefore, for the reactivation failure of the SCG, a new failure case needs to be included in the SCG failure information. And when detecting that the SCG activation fails, the UE initiates the transmission of a Failureinformation message. The failureType is set to SCG-activation failure.

Further, table 9 provides a new procedure for transmitting a FailureInformation message from the UE to one or more network nodes upon detection of SCG activation or reactivation failure. failureType is set to SCG-activation failure. For example, one or more network nodes may be a Master Node (MN).

TABLE 9

Referring to fig. 8, this will be explained with reference to fig. 1-7, and method 800 may be performed at UE 107. In an embodiment, upon reactivation or activation of the SCG, the UE 107 may perform the following operations:

at operation 801-a, method 800 includes determining reactivation or activation of a Secondary Cell Group (SCG) in which the UE is operating. In operation 801-B, the UE performs at least one of a first UE action and a second UE action based on a determination of reactivation of a Secondary Cell Group (SCG).

Thus, at operation 801, the method 800 includes performing another set of UE actions for Signaling Radio Bearers (SRBs) and DRBs. In operation 803 of the method 800, the UE determines whether SRB3 is established and suspended between the UE and at least one of the plurality of network nodes. At operation 805, the UE 107 performs restoring SRB3 based on determining that SRB3 is established and suspended between the UE and the at least one network node. In operation 807, the UE 107 performs recovery separating the transmission and reception of SRB over the SCG. The method 800 further performs, at operation 809, the UE 107 resuming transmission and reception of Data Radio Bearers (DRBs) on the SCG. In an embodiment of the present disclosure, the ue resumes transmission of Sounding Reference Signals (SRS) on the PSCell in operation 810.

Operations 803-810 include another set of UE actions. Another set of UE actions for SRBs upon reactivation may alternatively be referred to as a first set of UE actions.

Further, in operation 811, the UE performs a second set of UE actions for a multicast and broadcast service radio bearer (MRB). The second set of UE actions includes the methods at operations 811-815. Thus, operation 813, the method 800 comprises resuming multicast service reception on the SCG when the UE receives multicast service on the SCG via the MRB before deactivation. Further, in operation 815, the ue continues reception of the broadcast service on the SCG via the MRB.

In an implementation, the UE 107 may follow the actions shown in FIG. 4 above upon deactivation of the SCG by the UE 107. Further, operations 803-807 and 813-815 may correspond to operation 407 of FIG. 4.

Once the SCG has been re-activated,

for SRB:

SRB3 is restored (if established and suspended).

Resume separate SRB transmissions and receptions over the SCG.

For DRB:

the general actions are as follows:

resume transmission and reception of DRBs on SCG.

Transmission of Sounding Reference Signals (SRS) on the PSCell is resumed.

For MRB:

reception of the MRB on the SCG is resumed when the UE is receiving multicast services before deactivation.

When the UE is receiving the broadcast service, reception of the MRB on the SCG is continued.

According to another embodiment of the present disclosure, as ALT1, at least one of the following actions is performed, including:

the recovery evaluates the configuration(s) associated with the SCG received in measConfig.

The otherConfig associated with the SCG (if configured) is restored.

The timers T346a, T346b, T346c, T346d and T346e associated with the SCG are started or restarted (if not running).

The bap-Config associated with the SCG is restored (if configured).

The iab-IP-address configuration list associated with the SCG (if configured) is restored.

According to yet another embodiment of the present disclosure, as ALT2, at least one of the following acts is performed, including:

the configuration(s) associated with the SCG received in measConfig are reconfigured.

The otherConfig associated with the SCG is reconfigured (if configured).

Reconfiguring (if configured) the bap-Config associated with the SCG;

the iab-IP-address configuration list associated with the SCG is reconfigured (if configured).

In accordance with an embodiment of the present disclosure, the method 800 further includes starting at least one of the plurality of timers for a Radio Link Monitoring (RLM) entity upon activation or reactivation of the SCG based on a determination of an operational state of the plurality of timers configured on the SCG. The UE continues at least one of Beam Failure Detection (BFD) and Radio Link Monitoring (RLM) in at least one cell in the SCG using a previous configuration for RLM or BFD prior to SCG activation. The UE performs at least one of Beam Failure Detection (BFD) and Radio Link Monitoring (RLM) in at least one cell in the SCG by utilizing a new configuration for at least one of BFD and RLM, wherein the new configuration is received via at least one of RRC reconfiguration and rrburst message carrying CellGroupconfig information upon SCG activation.

According to an embodiment of the present disclosure, for an RLM entity: the timers T310, T312 on the SCG are started (if not running).

Accordingly, if the start timer T304 on the SCG is started (if not running).

In embodiments of the present disclosure, upon SCG activation, the UE utilizes the existing configuration of the RLM (e.g., configured at the time of SCG deactivation and/or applied prior to SCG activation) to continue monitoring radio link monitoring in at least one cell in the SCG. In another embodiment of the present disclosure, upon SCG activation, the UE continues to monitor radio link monitoring in at least one cell in the SCG with a new configuration of RLM. For example, a new configuration of RLM is received with SCG activation by RRC reconfiguration, rrcreseum message carrying CellGroupConfig.

In embodiments of the present disclosure, upon SCG activation, the UE utilizes the existing configuration of BFD (e.g., configured at the time of SCG deactivation and/or applied prior to SCG activation) to continue monitoring for beam failure detection in at least one cell in the SCG. In another embodiment of the present disclosure, upon SCG activation, the UE performs monitoring beam failure detection in at least one cell in the SCG with a new configuration of BFD. For example, a new configuration of BFD is received with SCG activation by RRC reconfiguration, rrcreseume message carrying CellGroupconfig.

In accordance with an embodiment of the present disclosure, the method 800 further includes, upon SCG deactivation, the UE performing an eighth set of UE actions for at least one of Radio Resource Management (RRM) measurements and Channel State Information (CSI) measurements. The eighth set of UE actions includes one of: (a) With existing RRC and/or CSI configurations, at least one of RRM measurements and CSI measurements are continuously performed in at least one cell in the SCG. Otherwise (b) continuing to perform at least one of RRM measurements and CSI measurements in at least one cell in the SCG with the newly received RRC and/or CSI configuration when the SCG is activated.

In embodiments of the present disclosure, upon SCG activation or reactivation, the UE performs RRC measurements and CSI measurements, such as at least one of:

at least one of RRM measurements and CSI measurements are continuously performed in at least one cell in the SCG with existing RRC and/or CSI configurations (e.g., configured at the time of SCG deactivation and/or applied prior to SCG activation).

At least one of RRM measurements and CSI measurements is continuously performed in at least one cell in the SCG with the newly received RRC and/or CSI configuration upon SCG activation. Upon SCG activation, a new configuration is received in an RRC reconfiguration message.

Further embodiments will be explained for PDCP entities and related UE actions upon reactivation of SCGs. According to a further embodiment of the present disclosure, the method 800 further comprises performing at least one of the following on the UE:

based on a determination that the PDCP suspension is due to deactivation of the SCG, a Packet Data Convergence Protocol (PDCP) is restored and a state variable of the PDCP entity is set to an initial value. And

based on a determination that the PDCP suspension is not due to deactivation of the SCG, data packets associated with the PDCP are forwarded to the SCG when needed.

Among the implementations as ALT1 are: if PDCP is suspended due to SCG deactivation, PDCP is restored, and a state variable of the PDCP entity is set to an initial value.

In the implementation as ALT 2: if the PDCP entity is not suspended due to SCG deactivation, the packet is forwarded to the SCG when needed.

Further embodiments will be explained for RLC entities and related UE actions upon reactivation of SCG.

According to a further embodiment of the present disclosure, the method 800 further comprises performing at least one of the following for the UE 107:

to recover the RLC entity of the DRB configured on the SCG, each state variable associated with the RLC entity is set to an initial value, where the state variable associated with the RLC entity is the variable that is reset during deactivation of the SCG. And

To recover the RLC entity of the DRB configured on the SCG, the use of the state variables is recovered based on the storage of the state variables during the deactivation of the SCG.

Accordingly, the UE restores the RLC entity of the DRB configured on the SCG. In an example, ALT1 comprises: if all state variables are reset during SCG deactivation, the state variables are set to initial values. In the example of ALT2, it includes: if a state variable of the time of SCG deactivation is stored, use is resumed upon reactivation.

According to another embodiment of the present disclosure, if there is a PSCell change when SCG is deactivated, and if it continues to be in a deactivated state, the method 800 further includes reconfiguring the PDCP/RLC/MAC entity for the target cell group according to the received corresponding configuration. Then, the conventional procedure is performed during the handover, and all parameters are set accordingly, and the SCG deactivation state is continued. Further, the method includes maintaining the status/state of the PDCP, RLC, MAC entity as it is in the source cell and maintaining the status/state of the SRB, DRB as it is in the source cell.

Further embodiments will be explained for MAC entities and related UE actions upon reactivation of SCGs.

In accordance with another embodiment of the present disclosure, the method 800 further includes performing another set of UE actions by the UE 107 for a Medium Access Control (MAC) entity when a Time Alignment (TA) timer is running continuously while the SCG is deactivated. Alternatively, another set of UE actions for a Medium Access Control (MAC) entity may be referred to as a third set of UE actions when a Time Alignment (TA) timer continues to run when the SCG is deactivated. Another set of UE actions includes:

when reactivation occurs in the same deactivation cell, initiation of a Random Access Channel (RACH) procedure is restricted during reactivation of the SCG.

When a handover to a new cell occurs, a RACH procedure to a target cell is initiated and a TA timer is started/restarted upon receipt of a timing advance command, wherein the RACH procedure is initiated based on one of a primary secondary cell (PSCell) or SCG needs to be in an active state and a deactivated state.

When a primary secondary cell (PSCell) or SCG is required to be in one of an active state and a deactivated state, initiation of a Random Access Channel (RACH) procedure is restricted.

In implementing ALT1, if the timealignmentTimer continues when the SCG is deactivated, if the timealignmentTimer is running and if activation occurs in the same deactivation cell, the third set for UE actions is as follows, then there is no need to initiate a RACH procedure while the SCG is activated. Furthermore, if there is a handover to a new cell, and if the target PSCell/SCG needs to be in active state, in implementation as ALT1, it includes initiating RACH procedure to the target cell, and starting/restarting timeAlignmentTimer upon receipt of timing advance command. In a further implementation, the third set of UE actions includes triggering a Random Access Channel (RACH) procedure to the target cell based on one of a primary secondary cell (PSCell) needs to be in an active state of SCG and a deactivated state of SCG when a handover to a new cell occurs. As an example, implementation of ALT2 includes preventing triggering of RACH procedures to the target cell. That is, the RACH procedure is not performed on the target cell.

According to another embodiment of the present disclosure, the method 800 further includes performing another set of UE actions for the MAC entity when the TA timer continues to run while the SCG is deactivated. When the TA timer continues to run while the SCG is deactivated, another set of UE actions for the MAC entity may alternatively be referred to as a fourth set of UE actions. Further, another set of UE actions for the MAC entity may correspond to operation 407 of fig. 4 when the TA timer continues to run at SCG deactivation.

Another set of UE actions includes: when the activation occurs in the same deactivated cell, a Random Access Channel (RACH) procedure is initiated while the SCG is activated, and thereafter, when a handover to a new cell occurs, a RACH procedure to a target cell is initiated, and a TA timer is started/restarted upon receipt of a timing advance command, wherein the RACH procedure is initiated based on one of a primary secondary cell (PSCell) needs to be in an activated state of the SCG and a deactivated state of the SCG.

Thus, if the target PScell/SCG needs to be in a deactivated state. In the implementation as ALT1, this includes initiating a RACH procedure to the target cell and starting/restarting the timealignmentTimer upon receipt of a timing advance command.

In a further implementation, ALT2 comprises a RACH procedure that does not trigger to the target cell. Start/restart timeAlignmentTimer. Furthermore, if the activation occurs in the same deactivation cell, the RACH procedure is initiated at the same time as the SCG is activated.

According to another embodiment of the present disclosure, the method 800 further comprises performing another set of UE actions for the MAC entity when the TA timer stops after deactivation of the SCG. When the TA timer stops after the deactivation of the SCG, the other set of UE actions for the MAC entity may alternatively be referred to as a sixth set of UE actions. Further, another set of UE actions when the time alignment timer stops after deactivation of the SCG may correspond to operation 407 of fig. 4.

Another set of UE actions includes initiating a RACH procedure during reactivation of the SCG when reactivation occurs in the same deactivated cell, and then initiating a RACH procedure to the target cell when a handover to a new cell occurs to start a time alignment timer upon receipt of a timing advance command, wherein the RACH procedure is initiated based on a need for a primary secondary cell (PSCell) to be in one of an activated state of the SCG and a deactivated state of the SCG.

Thus, in one implementation, if there is a handover to a new cell, if the target PSCell/SCG needs to be in an active state, a RACH procedure to the target cell is initiated and a timeAlignmentTimer is started upon receipt of a timing advance command. In an alternative implementation, if the target PSCell/SCG needs to be in a deactivated state, a RACH procedure to the target cell is initiated and a timeAlignmentTimer is started upon receipt of a timing advance command.

In a further implementation as ALT 2: if the timeAlignmentTimer is stopped when the SCG is deactivated, if the activation occurs in the same deactivated cell, the RACH procedure is initiated at the same time as the SCG is activated, if there is a handover to a new cell, if the target PSCell/SCG needs to be in active state, in the implementation as a method: upon receipt of the timing advance command, a RACH procedure to the target cell is initiated and a timeAlignmentTimer is started. In a further implementation, if the target PSCell/SCG needs to be in a deactivated state. As a method: initiate RACH procedure to target cell and start timeAlignmentTimer upon receiving timing advance command. In another embodiment of the present disclosure, the UE does not initiate RACH procedure if the timeAlignmentTimer is running when SCG is deactivated and the timeAlignmentTimer expires before activation/reactivation.

In an embodiment of the present disclosure, upon (re) activation of the SCG, the UE resumes reporting BSR and/or PHR on the SCG leg. According to another embodiment of the present disclosure, the method 800 includes another set of UE actions upon SCG reactivation. Another set of UE actions for SCG reactivation may alternatively be referred to as a seventh set of UE actions and corresponds to block 407 of fig. 4.

Upon (re) activation of the SCG, another set of UE actions includes restoring all DPS related parameters and the procedure should be restored. Further, when the UE receives the rrcreseume message, the UE resumes SRB2, SRB3 (if configured and not deactivated), and all DRBs except for DRBs (if any) related to SCGs if the SCG is deactivated.

In an embodiment of the present disclosure, upon (re) activation of the SCG, the UE triggers reporting of BSR and/or PHR on the SCG leg.

In embodiments of the present disclosure, upon (re) activation of the SCG, the UE continues to run the TA timer (if already running), or starts/restarts the TA timer.

In an embodiment of the present disclosure, upon deactivation and/or (re-) activation of the SCG, the UE triggers reporting of UE assistance information for conveying at least one piece of information to the network, as described in the previous section, but is not limited thereto.

In an embodiment of the present disclosure, when a UE needs to initiate SCG deactivation, it requests SCG deactivation from the network through UE assistance information. The UE assistance information message may include a new field conveying an "SCG deactivation request" and/or be conveyed using at least one existing field of the UE assistance information message (e.g., over-temperature, power saving, etc.). For the purpose of indicating an SCG deactivation request, the network configures the UE for UE assistance information and provides relevant configurations, such as prohibit timer Txxx and/or other timer tyy/parameter configurations, etc. Upon transmitting the UE assistance information message for SCG deactivation, the UE starts/restarts the timer Txxx. Upon receiving an acknowledgement or deactivation command from the network, the UE performs SCG deactivation. The prohibit timer Txxx is stopped. If no response is received, the UE may trigger the transmission of UE assistance information again under the direction of a timer, e.g. the prohibit timer Txxx expires, to avoid unnecessary frequent requests. If a rejection is received from the network, the UE stops the prohibit timer and no longer requests until a new cause of SCG deactivation is triggered or the request for SCG deactivation is redirected to the network with a new timer tyy.

In embodiments of the present disclosure, SCG deactivation and/or SCG activation or reactivation is triggered based on a change in dynamic capability of a UE engaged in multi-SIM (MUSIM) operation. The UE assistance information message carries updated capabilities (e.g., number of Rx and/or Tx links currently supported, PHY or RF capabilities, baseband computing capabilities, radio bands or band combinations supported, purpose or reason for SCG deactivation or actions, such as MUSIM operation, etc.) and reports to the network.

According to another embodiment of the present disclosure, the method 800 further comprises: after receiving the SCG activation or reactivation request from at least one of the plurality of network nodes, determining that the SCG reactivation fails based on expiration of a timer (T304), and thereafter, upon failure of activation or reactivation of the SCG, sending a FailureInformation message to the at least one of the plurality of network nodes. The failureType in the FailureInformation message is set to SCG-activation failure.

According to an embodiment, when the SCG is deactivated and the PSCell is very bad, the SCG activation or reactivation request is received once from at least one of the plurality of network nodes. Furthermore, if the UE 107 is unable to activate the PSCell, it may cause an SCG failure after the T304 timer expires, triggering an SCG failure. Further, the UE may use one of the existing failure reasons in the SCG failure information. However, it is difficult for the MN to distinguish between a conventional SCG failure and an SCG failure during SCG activation or reactivation. Therefore, for the reactivation failure of the SCG, a new failure case needs to be included in the SCG failure information.

According to the above procedure, the UE may transmit a FailureInformation message. Upon detecting failure of SCG activation, the UE initiates transmission of a FailureInformation message. The failureType is set to SCG-activation failure.

Some example embodiments disclosed herein may be implemented using processing circuitry. For example, some example embodiments disclosed herein may be implemented using at least one software program running on at least one hardware device and executing network management functions of a control element. Further, one or more UE actions as described above correspond to block 407 of fig. 4 without departing from the scope of the disclosure.

Although specific language has been used to describe the disclosure, any limitation thereby is not intended. It will be apparent to those skilled in the art that various operational modifications can be made to the method in order to implement the inventive concepts taught herein.

The figures and the preceding description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, some elements may be divided into a plurality of functional elements. Elements from one embodiment may be added to another embodiment. For example, the order of the processes described herein may be altered and is not limited to the manner described herein.

Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts necessarily need to be performed. Moreover, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of the embodiments is in no way limited by these specific examples. Many variations are possible, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material. The scope of the embodiments is at least as broad as the scope given by the appended claims.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as a critical, required, or essential feature or element of any or all the claims.

While the present disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a User Equipment (UE) in a wireless communication system, the method comprising:

determining a deactivation of a Secondary Cell Group (SCG) in which the UE is operating;

determining whether a Signaling Radio Bearer (SRB) associated with a multiple Radio Access Technology (RAT) -dual connectivity (MR-DC) is established for the UE;

in the case where MR-DC is established for the UE, suspending the SRB associated with the MR-DC;

suspending transmission and reception of Data Radio Bearers (DRBs) on the SCG;

suspending transmission of a Sounding Reference Signal (SRS) on a primary SCG cell (PSCell); and

the Medium Access Control (MAC) associated with the SCG is reset.

2. The method of claim 1, further comprising:

when a UE receives a multicast service on an SCG via a multicast and broadcast service radio bearer (MRB), suspending or releasing the MRB;

continuing the reception of the broadcast service on the SCG via the MRB; and

multicast Broadcast Service (MBS) -specific MAC of SCG is maintained.

3. The method of claim 1, further comprising:

for a Packet Data Convergence Protocol (PDCP) layer of a PDCP entity, changing a primary uplink path to a primary cell group (MCG) for a separate DRB; and

a Radio Link Control (RLC) entity of the DRB configured on the SCG is suspended,

Wherein the method further comprises, for changing the primary uplink path to the MCG RLC entity, one of suspending PDCP or continuing and resuming PDCP configured with DRB of the key touse set as secondary,

wherein the method further comprises, for an RLC entity suspending DRBs configured on the SCG, resetting one of each state variable associated with the RLC entity and storing a current value of the state variable associated with the RLC entity, and

wherein the method further comprises, for a Medium Access Control (MAC) entity following deactivation of the SCG, at least one of: continuing a Time Alignment (TA) timer, stopping the TA timer, stopping reporting at least one of a Buffer Status Report (BSR) and a Power Headroom Report (PHR) on the SCG leg, cancelling all pending triggers for at least one of the BSR and PHR on the SCG leg, and aborting the Dynamic Power Sharing (DPS) related procedure.

4. The method of claim 1, further comprising:

detection of beam failure in continuing monitoring cells in SCG, and

triggering a Beam Failure Recovery (BFR) procedure based on detection of a beam failure associated with a secondary cell (SCell), or initiating a Random Access Channel (RACH) procedure based on detection of a beam failure associated with a primary secondary cell (PSCell), or

5. The method of claim 1, further comprising at least one of:

stopping a plurality of timers configured on an SCG for a Radio Link Monitoring (RLM) entity based on a determination of an operational status of the plurality of timers;

continuing at least one of BFD and RLM in at least one cell in the SCG with a previous configuration for Beam Failure Detection (BFD) or Radio Link Monitoring (RLM) prior to deactivation of the SCG;

stopping at least one of Beam Failure Detection (BFD) and Radio Link Monitoring (RLM) in at least one cell in the SCG;

performing at least one of BFD and RLM in at least one cell in SCG by using a new configuration of at least one of BFD and RLM, wherein the new configuration is received via at least one of RRC reconfiguration and rrcreseum message carrying CellGroupConfig information when SCG is deactivated;

discarding Discontinuous Reception (DRX) configuration of the SCG;

maintaining a DRX configuration of the SCG, wherein the UE does not apply DRX operation of the SCG; and

a Channel State Information (CSI) report of CSI measurement is transmitted during a period corresponding to an on duration timer of the DRX configuration.

6. The method of claim 1, further comprising:

detecting a Master Cell Group (MCG) failure during a deactivated state of the SCG; and

to report a detected MCG failure, at least one of the following operations is performed:

a Random Access Channel (RACH) procedure is triggered based on a previously stored SCG configuration,

after the RACH procedure is completed, each of the SCG and the suspended SRB3 is activated,

after SCG activation, sending an MCGFailureInformation message associated with the detected MCG failure to at least one of the plurality of network nodes, and

7. The method of claim 1, further comprising:

at SCG deactivation, at least one of a Radio Resource Management (RRM) measurement and a Channel State Information (CSI) measurement for the SCG cell is performed for at least one of the RRM measurement and the CSI measurement such that a frequency of the at least one of the RRM measurement and the CSI measurement is reduced, wherein the at least one of:

receiving RRM configuration and CSI configuration from at least one of a plurality of network nodes when SCG is deactivated, and

the RRM configuration and CSI configuration are based on at least one of signal conditions and UE mobility information.

8. A User Equipment (UE) in a wireless communication system, the UE comprising:

a transceiver configured to transmit and receive signals; and

a controller coupled with the transceiver and configured to:

determines the deactivation of the Secondary Cell Group (SCG) in which the UE is operating,

determining whether a Signaling Radio Bearer (SRB) associated with a multiple Radio Access Technology (RAT) -dual connectivity (MR-DC) is established for the UE,

in the case where MR-DC is established for the UE, SRBs associated with the MR-DC are suspended,

the transmission and reception of Data Radio Bearers (DRBs) on the SCG is suspended,

suspending transmission of Sounding Reference Signals (SRS) on primary SCG cell (PSCell), and

the Medium Access Control (MAC) associated with the SCG is reset.

9. The UE of claim 8, wherein the controller is further configured to:

when a UE receives a multicast service on an SCG via a multicast and broadcast service radio bearer (MRB), the MRB is suspended or released,

continuing reception of broadcast services over SCG via MRB, and

multicast Broadcast Service (MBS) -specific MAC of SCG is maintained.

10. The UE of claim 8, wherein the controller is further configured to:

for a Packet Data Convergence Protocol (PDCP) layer of a PDCP entity, changing a primary uplink path to a primary cell group (MCG) for a separate DRB, and

wherein the controller is further configured to perform one of suspending PDCP or continuing and resuming PDCP configured with DRB of key touse set as secondary, for changing the primary uplink path to the MCG RLC entity, and

wherein the controller is further configured to perform one of resetting each state variable associated with the RLC entity and storing a current value of the state variable associated with the RLC entity for the RLC entity suspending the DRB configured on the SCG.

11. The UE of claim 8, wherein the controller is further configured to:

detection of beam failure in continuing monitoring cells in SCG, and

12. The UE of claim 8, wherein the controller is further configured to perform at least one of:

discarding Discontinuous Reception (DRX) configuration of the SCG;

13. The UE of claim 8, wherein the controller is further configured to:

14. The UE of claim 8, wherein the controller is further configured to, after deactivation of the SCG, perform at least one of the following for a Medium Access Control (MAC) entity:

continuing with the Time Alignment (TA) timer,

the TA timer is stopped and the timer is started,

stopping reporting at least one of a Buffer Status Report (BSR) and a Power Headroom Report (PHR) on the SCG leg,

cancel all pending triggers for at least one of BSR and PHR on SCG leg, and

the Dynamic Power Sharing (DPS) correlation process is aborted.

15. The UE of claim 8, wherein the controller is further configured to: