Method and apparatus for performing LTM coordination in dual connectivity

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. The present disclosure relates to a method of performing lower layer (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity. The method includes a primary node (MN) determining frequency information for a terminal by a secondary node (SN) for LTM and L3 mobility. Further, the method includes transmitting an inter-node message including the frequency information to the SN. Further, the method includes receiving at least one of configuration information associated with the LTM measurement and the LTM candidate cell configured by the SN for the terminal based on the inter-node message. Further, the method includes determining a measurement gap of the terminal and an LTM candidate cell configuration. Thereafter, the method includes transmitting the measurement gap and the LTM candidate cell configuration to the SN and the terminal.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the field of wireless communication. More specifically, the present disclosure relates to a method and system for performing lower layer (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity. BACKGROUND

[0002] 5G mobile communication technologies define wide frequency bands so that high transmission rates and new services are possible, and are not only implemented in "Sub 6 GHz" frequency bands, but also implemented in "6 GHz to 60 GHz" bands (millimeter wave bands) and even "above 60 GHz" bands. In addition, 6G mobile communication technologies are considered to be implemented in terahertz bands (for example, 95 GHz to 3 THz bands) to overcome the limitations of 5G mobile communication technologies and to achieve the next level of wireless big data communication, wireless Internet of Things (IoT), wireless backhaul, and the like. In the case of 6G mobile communication technologies, research is being conducted on technologies such as the use of a space-time material, a space-time mesh, and a space-time crystal, and the use of a quantum computer and a superconductor.

[0003] At the early stage of 5G mobile communication technologies development, in order to support services and meet the performance requirements with respect to enhanced mobile broadband (eMBB), ultra-reliable and low-latency communications (URLLC), and massive machine-type communications (mMTC), research is being conducted on, for example, techniques for reducing radio-wave path loss and increasing radio-wave transmission distances in mmWave, beamforming and massive MIMO, support parameters for dynamic operation of time slots and subcarriers (for example, operating multiple subcarrier intervals), initial access techniques for supporting multi-beam transmission and wideband, definition and operation of a BWP (bandwidth part), new channel coding methods such as a LDPC (low-density parity check) code for large data transmission and a polar code for highly reliable transmission of control information, L2 pre-processing, and network slicing for providing a dedicated network dedicated to a specific service.

[0004] Currently, with respect to services supported by 5G mobile communication technologies, the industry is continuously discussing improvements and performance enhancements with respect to initial 5G mobile communication technologies, and physical layer standardization has been completed with respect to, for example, V2X (vehicle-to-everything) for assisting driving decisions based on information about the positions and states of vehicles transmitted by the vehicles and for improving user convenience, NR-U (new radio-unlicensed) for operating systems in compliance with various regulatory requirements in unlicensed bands, NR UE power saving, non-terrestrial networks (NTN) that are direct communication of UEs with satellites as a means for securing coverage in areas where communication with terrestrial networks is not possible, and positioning.

[0005] In addition, standardization for air interface architecture / protocol of the following technologies has been ongoing: Industrial Internet of Things (IIoT) for support of new services through interworking and convergence with other industries; IAB (Integrated Access and Backhaul) for providing nodes for network service area expansion by supporting a wireless backhaul link and an access link in an integrated manner; mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover; and two-step random access (2-step RACH for NR) for simplifying a random access procedure. At the same time, standardization for system architecture / service of the following technologies has been ongoing: 5G baseline architecture for combination of network functions virtualization (NFV) and software-defined networking (SDN) technologies (e.g., service-based architecture or service-based interface); and mobile edge computing (MEC) for receiving services based on UE location.

[0006] With the commercialization of 5G mobile communication systems, exponentially increasing connected devices will access the communication network, and thus it is expected that enhanced functionality and performance of 5G mobile communication systems and integrated operations of connected devices will be necessary. For this reason, new research on the following technologies has been scheduled: extended reality (XR) for efficient support of AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), etc.; 5G performance improvement and complexity reduction by utilizing artificial intelligence (AI) and machine learning (ML); AI service support; metaverse service support; and drone communication.

[0007] In addition, such development of 5G mobile communication systems will lay the groundwork not only for developing new waveforms for providing coverage in the terahertz bands of 6G mobile communication technologies, but also for developing multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas, and massive antennas; metamaterial-based lenses and antennas for improving coverage of terahertz band signals; high-dimensional space multiplexing technology using OAM (Orbital Angular Momentum); and RIS (Reconfigurable Intelligent Surface), full-duplex technologies for improving frequency efficiency of 6G mobile communication technologies and improving system networks; AI-based communication technologies for implementing system optimization from the design stage by utilizing satellites and AI (Artificial Intelligence) and internalizing end-to-end AI support functions; and next-generation distributed computing technologies for implementing services at a complexity level exceeding the limit of UE operating capabilities by utilizing super-high-performance communication and computing resources. SUMMARY

[0008] TECHNICAL PROBLEM

[0009] Currently, there is a need to enhance the execution of LTM coordination in dual connectivity of a wireless communication system.

[0010] SOLUTION TO THE PROBLEM

[0011] The foregoing overview is merely illustrative and is not intended to be limiting in any way. Further aspects, embodiments, and features will become apparent from the following detailed description, taken in conjunction with the accompanying figures and the following detailed description.

[0012] In one embodiment, a method of performing lower layer (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity is disclosed. The method includes determining, by a secondary node (SN), frequency information for a UE for LTM and L3 mobility. Further, the method includes transmitting, to the SN, an inter-node message including the frequency information. Further, the method includes receiving at least one of configuration information associated with LTM measurements and LTM candidate cells for the UE configured by the SN based on the inter-node message. Further, the method includes determining measurement gaps and LTM candidate cell configuration for the UE based on at least one of the LTM measurements and the configuration information of the LTM candidate cells received from the SN (104). Thereafter, the method includes transmitting, to the SN and the UE, the measurement gaps and the LTM candidate cell configuration.

[0013] In one embodiment, a master node for performing lower layer (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity is disclosed. The master node includes one or more processors and a memory. The memory stores instructions executable by the processors that, upon execution, cause the one or more processors to determine frequency information to be used by a secondary node (SN) for a UE for LTM and L3 mobility. Further, the one or more processors are configured to transmit, to the SN, an inter-node message including a maximum number of serving frequencies to be configured by the SN for the UE and a number of frequencies configured by the MN. Further, the one or more processors are configured to receive at least one configuration information associated with LTM measurements and LTM candidate cells for the UE configured by the SN based on the inter-node message. Further, the one or more processors are configured to determine measurement gaps and LTM candidate cell configuration for the UE based on at least one of the LTM measurements and the configuration information of the LTM candidate cells received from the SN (104). Thereafter, the one or more processors are configured to transmit, to the SN and the UE, the measurement gaps and the LTM candidate cell configuration.

[0014] In one embodiment, a method of performing lower stratum (L1 / L2 stratum) triggered mobility (LTM) coordination in dual connectivity is disclosed. The method includes receiving an inter-node message from a master node (MN) associated with a UE, the inter-node message including frequencies to be used by a SN for LTM and L3 mobility for the UE. Further, the method includes determining at least one configuration information associated with LTM measurements and LTM candidate cells based on the inter-node message. Further, the method includes transmitting the at least one configuration information associated with LTM measurements and LTM candidate cells to the MN. Thereafter, the method includes receiving measurement gaps and LTM candidate cell configuration for the UE from the MN by the SN.

[0015] In one embodiment, a secondary node for performing lower stratum (L1 / L2 stratum) triggered mobility (LTM) coordination in dual connectivity is disclosed. The secondary node includes one or more processors and a memory. The memory stores instructions executable by the processors, which upon execution cause the one or more processors to receive an inter-node message from a MN containing frequency information to be used by a SN for a UE. Further, the one or more processors are configured to determine at least one of configuration information associated with LTM and LTM candidate cells based on the inter-node message. Further, the one or more processors are configured to transmit at least one of the configuration information associated with LTM measurements and LTM candidate cells to the MN based on at least one of the configuration information of LTM measurements and LTM candidate cells received from the SN (104). Thereafter, the one or more processors are configured to receive measurement gaps and LTM candidate cell configuration for the UE from the MN.

[0016] The foregoing overview is illustrative only and is not intended to serve as limiting. Other aspects, embodiments, and features will become apparent from the following detailed description, which, when taken in conjunction with the drawings, illustrate various embodiments. OF THE DRAWINGS BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate examples of the present embodiments and together with the description, serve to explain the disclosed principles. The same reference numbers in all the drawings identify the same components and features. At least one apparatus and method in accordance with embodiments of the disclosed subject matter will now be described, by way of example only, and with reference to the accompanying drawings: Figure 1 An environment for performing lower stratum (L1 / L2 stratum) triggered mobility (LTM) coordination in dual connectivity is shown in accordance with embodiments of the present disclosure; Figure 2 A detailed diagram of a master node for performing lower stratum (L1 / L2 stratum) triggered mobility (LTM) coordination in dual connectivity is shown in accordance with embodiments of the present disclosure; Figure 3 Figure 9 illustrates a detailed diagram of a secondary node for performing lower stratum (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity, according to embodiments of the disclosure; Figure 4A Figure 10 illustrates an exemplary diagram for performing lower stratum (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity, according to some embodiments of the disclosure; Figure 4B Figure 11 illustrates an exemplary diagram for performing lower stratum (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity, according to some embodiments of the disclosure; Figure 4C Figure 12 illustrates an exemplary diagram for performing lower stratum (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity, according to some embodiments of the disclosure; Figure 5 Figure 13 illustrates an exemplary flow diagram of method steps of a master node for performing lower stratum (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity, according to some embodiments of the disclosure; Figure 6 Figure 14 illustrates an exemplary flow diagram of method steps of a secondary node for performing lower stratum (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity, according to some embodiments of the disclosure; and Figure 7 Figure 15 illustrates a block diagram of a general computing system for performing lower stratum (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity, according to embodiments of the disclosure.

[0018] Figure 8 Figure 16 is a block diagram illustrating a structure of a user equipment (UE or terminal) according to embodiments of the disclosure; and

[0019] Figure 9 Figure 17 is a block diagram illustrating a structure of a base station (BS) according to embodiments of the disclosure.

[0020] The attached drawings for merely given for illustrative purposes and therefore should not be considered to narrow the scope of the disclosure in any way. Upon considering this during the grant of any patent rights, the scope of the disclosure should be measured only in accordance with the claims that have been appropriately considered. DETAILED DESCRIPTION

[0021] In wireless communication, user equipment (UE) moves across various cells. Mobility is performed using a procedure called cell reselection in the process of moving UE from a source cell to a target cell. Traditionally, mobility is performed using a procedure called handover in RRC connected (RRC CONNECTED) mode. Mobility is triggered using RRC messages and in RRC connected mode, network controlled mobility is applied to the UE. In RRC connected mode, explicit RRC signaling (RRC messages) is required to trigger next generation NodeB (gNB) in new radio (NR). Handover in NR is performed using three steps such as handover preparation, handover execution, and handover completion. The gNB can configure the UE to report measurement values and based on the reported measurement values or based on its own understanding of the network topology, the gNB will send an RRC reconfiguration message to handover the UE from the source cell to the target cell. The UE accesses the target cell and sends an RRC reconfiguration complete message to the source cell.

[0022] In an alternative approach, the gNB can configure the UE with execution conditions to trigger handover and once the execution conditions are met, the UE can move to the target cell and send an RRC reconfiguration complete. However, in the traditional approach, the UE performs handover by sending layer 3 (RRC) messages which causes considerable signaling overhead and latency issues. Therefore, there is a need to reduce signaling overhead and latency issues that occur in the process of moving the UE from the source cell to the target cell. 3GPP Release 18 considers lower layer (L1 / L2 layer) triggered mobility (also called LTM) to address this issue.

[0023] The information disclosed in part of the background of the disclosure is only for enhancing the understanding of the general background of the present invention, and should not be regarded as recognizing or implying in any form that this information forms the prior art known to those skilled in the art.

[0024] In this document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation of the subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0025] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the disclosure is not to be limited to the particular

[0026] The terms“comprises”,“comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, device, or method that comprises a list of components or steps does not include only those components or steps but can include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements of a device, system, or apparatus proceeded by“comprises...” does not, without more constraints, preclude the existence of other elements or additional elements in the device, system, or apparatus.

[0027] In the following detailed description of embodiments of the disclosure, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the disclosure can be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the application, and it is to be understood that other embodiments can be utilized and that changes can be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0028] Inventive concept

[0029] For the purposes of the present disclosure, relevant 3GPP specifications such as TS 38.300, TS 38.331, TS 38.321, TS 37.340 can be considered as prior art. According to 3GPP, the goal of LTM is to enable serving cell change via L1 / L2 signaling in order to reduce latency, overhead, and interruption time. The network gNB can configure multiple candidate cells for a UE to allow fast application of the configuration of the candidate cell. The network can also send a MAC CE or L1 signaling to dynamically switch the UE from the source cell to one of the configured candidate cells. Furthermore, LTM can be triggered based on L1 measurements instead of L3 measurements.

[0030] 3GPP suggests performing LTM without resetting lower layers such as MAC to avoid data loss and minimize additional delay for data recovery as much as possible. The gNB can provide the LTM Candidate Configuration, i.e. configure LTM candidate cells for candidate target cells through one RRCReconfiguration message or through one CellGroupConfig per candidate target cell or through any similar RRC structure or information element (IE) containing similar fields (e.g. a new IE LTM-CandidateConfig can be defined as an ASN.1 sequence containing CellGroupConfig and some other information elements in RRCReconfiguration). The gNB can further release or modify the candidate configuration. The UE can store the LTM configuration for other candidate cells even after moving to a candidate cell through LTM.

[0031] To avoid transmitting a large number of messages over the air interface, the gNB can provide the LTM Candidate Configuration as an incremental configuration instead of a full configuration. The gNB can indicate the UE to use the source cell configuration as a reference for the incremental configuration or explicitly provide the reference configuration.

[0032] The gNB can provide the LTM Candidate Configuration, i.e. configure LTM candidate cells for candidate target cells through one RRCReconfiguration message or through one CellGroupConfig per candidate target cell or through any similar RRC structure or IE containing similar fields (e.g. a new IE LTM-CandidateConfig can be defined as an ASN.1 sequence containing CellGroupConfig and some other information elements in RRCReconfiguration). The gNB can further release or modify the candidate configuration. The UE can store the LTM configuration for other candidate cells even after moving to a candidate cell through LTM. The gNB can also provide the UE with the configuration for performing LTM measurements (L1 measurements performed by the UE for LTM are referred to as LTM measurements) for different candidate frequencies and candidate cells and report based on the performed LTM measurements.

[0033] The gNB provides the reference configuration, L1 measurement configuration and candidate cell configuration in the RRC ASN.1 sequence for LTM configuration. An exemplary sequence is given as follows.

[0034]

[0035] The UE reports the LTM measurement value to the source gNB (distributed unit, DU, of the source gNB), and the source gNB will send a downlink MAC CE, such as a cell handover command. Upon receiving the cell handover command, the UE moves to the target cell, which can be in the same gNB DU or can be in a different gNB DU.

[0036] Dual connectivity

[0037] 3GPP specifies dual connectivity, or more professionally “multi-radio dual connectivity”, in specifications such as TS 37.340. The following gives a summary of details about dual connectivity and measurement gap operation for dual connectivity.

[0038] NG-RAN supports multi-radio dual connectivity (MR-DC) operation whereby a UE in an RRC connection is configured to utilize radio resources provided by two different schedulers, located in two different NG-RAN nodes connected via a non-ideal backhaul, one node providing NR (New Radio) access and the other node providing E-UTRA (Evolved UMTS Terrestrial Radio Access) or NR access. One node acts as a master node (MN) and the other as a secondary node (SN). The MN and SN are connected via a network interface and at least the MN is connected to the core network. NG-RAN supports NG-RAN E-UTRA-NR dual connectivity (NGEN-DC) where a UE is connected to one NG-eNB (E-UTRA base station that can connect to a 5G core) acting as a MN and one gNB (5G base station) acting as a SN. NG-RAN also supports NR-E-UTRA dual connectivity (NE-DC) where a UE is connected to one gNB acting as a MN and one NG-eNB acting as a SN.

[0039] PSCell change and PSCell addition

[0040] PSCell change can occur due to mobility and can or can not be associated with a secondary node change (SN change). The secondary node change procedure is initiated by the MN or the SN and is used to transfer the UE context from the source SN to the target SN and change the secondary cell group (SCG) configuration in the UE from one SN to another.

[0041] Conditional PSCell change (CPC) is defined as a PSCell change performed by the UE when a condition for execution is met. The UE can be configured with a condition for execution and an RRC message (like RRC reconfiguration) to execute when the condition is met for one or more candidate cells. The UE starts evaluating the condition for execution upon receiving the CPC configuration and stops evaluating the condition for execution once the PSCell change is triggered. Intra-SN CPC without the need for MN involvement, and inter-SN CPC initiated by the MN or SN are supported.

[0042] The following principles apply to CPC: - The CPC configuration contains the configuration of the CPC candidate PSCell and the condition for execution, and can contain the MN configuration for inter-SN CPC.

[0043] The condition for execution can consist of one or two trigger conditions (CPC event A3 / A5 as defined in TS 38.331). Only a single RS type is supported and up to two different trigger quantities (e.g. RSRP and RSRQ, RSRP and SINR, etc.) can be configured simultaneously for evaluating the condition for execution of a single candidate PSCell.

[0044] Prior to meeting any CPC execution condition, upon receiving a PSCell change command or a PCell change command, the UE performs the PSCell change procedure as described in clauses 10.3 and 10.5 of TS 38.331 or the PCell change procedure as described in clause 9.2.3.2 of TS 38.300 [3] or clause 10.1.2.1 of TS 36.300 [2], regardless of any previously received CPC configuration. Upon successful completion of the PSCell change procedure or the PCell change procedure, the UE releases all stored CPC configurations.

[0045] Upon performing CPC, the UE does not need to continue evaluating the condition for execution for other candidate PSCells.

[0046] Upon successful execution of the CPC procedure, the UE releases all stored CPC configurations.

[0047] Upon releasing the SCG, the UE releases the stored CPC configuration.

[0048] 3GPP Release 18 enhances CPC by selectively activating cell groups, where the UE does not release the stored CPC configuration for one or more candidate PSCells and the source PSCell based on network input.

[0049] The MN adds a PSCell in a PSCell addition procedure. The PSCell addition procedure that is only executed when PSCell addition conditions are met is referred to as conditional PSCell addition (CPA). It should be noted that 3GPP specifications such as TS 37.340, TS 38.331, TS 38.300 can be used as prior art to the present disclosure.

[0050] For a UE in dual connectivity, both the MN and the SN can provide LTM configuration including LTM candidate cells and LTM reference configuration. The MN and the SN can also provide LTM measurement configuration to the UE.

[0051] Measurements in dual connectivity

[0052] Measurements in dual connectivity are described based on 3GPP specification TS 37.340, V17.2.0.

[0053] Measurements can be independently configured by the MN and the SN (intra-RAT measurements on serving and non-serving frequencies). The MN indicates the maximum number of frequency layers that can be used in the SN and the measurement identities for intra- and inter-frequency measurements to ensure that the UE capability is not exceeded. In MR-DC, to assist the MN in identifying the measurement type, the SN indicates to the MN a list of SCG serving frequencies. In NR-DC, to assist the SN in identifying the measurement type, the MN also indicates to the SN a list of MCG serving frequencies. The SN can also request from the MN a new maximum value for the number of measurement identities it can configure and, based on the capability coordination principles described in section 7.3 of TS 37.340, it is up to the MN to decide whether to accept the SN request. If the SN receives from the MN a new value for the maximum number of measurement identities, it is the responsibility of the SN to ensure that the measurement identities it configures comply with the new limit.

[0054] If the MN and the SN both configure measurements on the same carrier frequency, the configurations need to be consistent (if the network wants to ensure that the configurations are treated as a single measurement layer). Each node (MN and SN) can independently configure the threshold for SpCell quality. In (NG)EN-DC scenarios, when the PCell quality is above the threshold configured by the MN, the UE still needs to perform the inter-RAT measurements configured by the MN on the SN RAT (while not needing to perform intra-RAT measurements); when the PSCell quality is above the threshold configured by the SN, the UE does not need to perform the measurements configured by the SN. In NR-DC or NE-DC scenarios, when the PCell quality is above the threshold configured by the MN, the UE does not need to perform the measurements configured by the MN, and when the PSCell quality is above the threshold configured by the SN, the UE does not need to perform the measurements configured by the SN.

[0055] In MR-DC, both MN and SN can configure CGI reporting. The MN can configure CGI reporting for intra- and inter-RAT cells, but the SN can only configure CGI reporting for intra-RAT cells. At any point in time, the UE can be configured with at most one CGI reporting configuration. For CGI reporting coordination, the SN sends the CGI measurement request and embedded CGI reporting configuration to the MN. Optionally, the SN sends the unknown cell information to the MN. If there is no ongoing CGI reporting measurement on the UE side, the MN forwards the SN CGI measurement configuration to the UE. Otherwise, the MN rejects the request by sending an X2 / Xn reject message. In case the SN indicates unknown cell information and there is already CGI information of the requested cell in the MN, the MN can also reject the request and send the CGI information of the requested cell to the SN. The SN cannot use SRB3 to configure CGI measurement.

[0056] In SCG deactivated state, both MN configured RRM measurements and SN configured RRM measurements are supported. When in deactivated SCG state, the PSCell measurement cycle is configured by RRC.

[0057] When no radio bearer SRB3 is configured or SCG is deactivated, the measurement reports configured by the SN are sent on SRB1. When SRB3 is configured and the radio bearer of the SCG transmission is not suspended and the SCG is not deactivated, the measurement reports configured by the SN are sent on SRB3.

[0058] In MN initiated SN change procedure, measurement results related to the target SN can be provided by the MN to the target SN. In SN initiated SN change procedure, measurement results of the target SN can be forwarded from the source SN to the target SN via the MN. In inter-MN handover (whether or not a SN change procedure is performed), measurement values related to the target SN can be provided by the source MN to the target MN.

[0059] When measurement results according to measurement configuration from the MN are provided by the MN to the SN in SgNB Addition Request / SN Addition Request message, these measurement results are encoded according to SN RRC. In SN initiated SN change procedure, when measurement results according to measurement configuration from the SN are provided by the MN to the SN in SgNB Addition Request / SN Addition Request message, these measurement results are encoded according to SN RRC.

[0060] The measurement gap according to UE or according to FR can be configured, depending on UE capability to support independent FR measurement and network preference. The gap according to UE is applicable for both FR1 (E-UTRA, UTRA-FDD and NR) and FR2 (NR) frequencies. For the gap according to FR, two independent gap patterns are configured for FR1 and FR2 respectively (i.e. FR1 gap and FR2 gap). The UE can also be configured with a gap sharing configuration for the gap according to UE (applicable for the gap according to UE) or with two separate gap sharing configurations (applicable for FR1 and FR2 measurement gap respectively).

[0061] If the gap according to UE is used, the MN decides the gap pattern and the related gap sharing configuration. If the gap according to FR is used, under EN-DC and NGEN-DC, the MN decides the FR1 gap pattern for FR1 and the related gap sharing configuration, while the SN decides the FR2 gap pattern for FR2 and the related gap sharing configuration. Under NE-DC and NR-DC, the MN decides both FR1 and FR2 gap patterns and the related gap sharing configurations.

[0062] Under EN-DC and NGEN-DC, the measurement gap configuration from the MN to the UE indicates from the MN whether the gap according to UE or FR1 gap configuration is configured. The MN also indicates to the SN the configured measurement gap pattern according to UE or FR1 and the gap purpose (according to UE or according to FR1). Measurement gap configuration assistance information can be exchanged between the MN and the SN. For the case of gap according to UE, the SN indicates to the MN the list of SN configured frequencies in FR1 and FR2 that are measured by the UE. For the case of gap according to FR, the SN indicates to the MN the list of SN configured frequencies in FR1 that are measured by the UE, and the MN indicates to the SN the list of MN configured frequencies in FR2 that are measured by the UE. In NE-DC, the MN indicates to the SN the configured measurement gap pattern according to UE or FR1. The SN can provide a gap request to the MN without indicating any frequency list.

[0063] In NR-DC, the MN indicates to the SN the configured measurement gap pattern according to UE, FR1 or FR2 and the gap purpose. The SN can indicate to the MN the list of SN configured frequencies in FR1 and FR2 that are measured by the UE. In (NG)EN-DC and NR-DC, SMTC can be used for PSCell addition / PSCell change to assist the UE to find the SSB in the target PSCell. In case both the MN and the SN provide SMTC for the target PSCell, which one to use depends on UE implementation. In prior art, the measurement gap is only used for L3 measurement.

[0064] Inter-node messaging between MN and SN

[0065] In NR, the SN sends the inter-node RRC message CG-Config to the MN to inform it of the configurations it has used and to request configurations it can use. CG-Config is defined in TS 38.331, such as TS 38.331 V17.2.0.

[0066]

[0067] The MN sends the inter-node RRC message CG-ConfigInfo to the SN to inform it of the configurations it is allowed to use and other information. CG-ConfigInfo is defined in TS 38.331, such as TS 38.331 V17.2.0.

[0068] Both the MN and the SN can configure LTM measurements and LTM candidate cells. Therefore, there is a need to coordinate the capabilities of both the MN and the SN.

[0069] In one embodiment, the MN-SN interaction for LTM is through CG-ConfigInfo. In one embodiment, the MN indicates to the SN the maximum number of frequencies that the SN can configure for LTM measurements using the IE maxMeasFreqsSCG. In the current system, maxMeasFreqsSCG contains the maximum number of frequencies that the SN can configure for L3 mobility. This disclosure proposes that the MN includes in the IE maxMeasFreqsSCG the maximum number of frequencies configured for LTM and L3 mobility. In this way, the MN informs the SN of the maximum number of frequencies that it can configure together for L3 handover and LTM. When configuring the measurements for LTM and L3, the SN configures at most maxMeasFreqsSCG layers, including both measurements configured for LTM and L3. In another embodiment, the MN indicates to the SN the maximum number of NR inter-frequency carriers that the SN is allowed to configure for LTM measurements. This is done using a separate RRC IE, such as LTMmaxMeasFreqsSCG, which informs the SN of the maximum number of NR inter-frequency carriers that the SN is allowed to configure PSCells for LTM measurements and is sent by the MN to the SN.

[0070] In another embodiment, the MN-SN interaction for LTM is through CG-Config. Here, the SN includes the LTM measurement configuration in CG-Config and sends it to the MN. The LTM measurement configuration sent from the SN to the MN includes resource configuration such as time domain information (including SMTC information, periodicity, SSB locations in a burst, etc.) and frequency domain information such as subcarrier spacing, input frequencies. The SN also sends the allowed transmit power to the MN.

[0071] MN-SN interaction for LTM through CG-Configlnfo. The MN informs the SN the maximum number of frequencies it configures for the UE for LTM measurement. In one embodiment, the MN informs the SN through an inter-node RRC message (such as CG-Configlnfo in NR) the above information. In one embodiment, for NR, the MN includes in the ConfigRestrictlnfoSCG IE sent by the MN to the SN the maximum number of frequencies the SN can configure for the UE for LTM measurement.

[0072] In one embodiment, the MN indicates to the SN the maximum number of frequencies the SN can configure for the UE for LTM measurement through one of the following ways: 1. Using the IE maxMeasFreqsSCG. In the current NR system, maxMeasFreqsSCG contains the maximum number of frequencies the SN can configure for L3 mobility. This disclosure proposes that the MN includes in the IE maxMeasFreqsSCG the maximum number of frequencies configured for LTM and L3 mobility. In this way, the MN informs the SN the maximum number of frequencies it can configure together for L3 handover and LTM. When configuring the measurements for LTM and L3, the SN configures at most maxMeasFreqsSCG layers, including both measurements configured for LTM and L3 mobility.

[0073] 2. The MN indicates to the SN the maximum number of NR inter-frequency carriers the SN is allowed to configure for LTM measurement. This is done using a separate NR RRC IE (such as LTMmaxMeasFreqsSCG) that informs the SN the maximum number of NR inter-frequency carriers the SN is allowed to configure PSCells for LTM measurement and is sent by the MN to the SN.

[0074] An example specification excerpt is given below:

[0075] In one embodiment, the maximum value of maxMeasFreqsMNLTM is equal to maxMeasFreqsMN. In one embodiment, the maximum value of maxMeasFreqsMNLTM is a new value that is smaller than maxMeasFreqsMN.

[0076] LTMmaxMeasFreqsSCG can be defined in TS 38.331 as follows.

[0077] LTMmaxMeasFreqsSCG

[0078] Indicates the maximum number of NR inter-frequency carriers the SN is allowed to configure PSCells for LTM measurement.

[0079] In one embodiment, the SN configures the UE with less than or equal to LTMmaxMeasFreqsSCG frequencies for LTM measurements.

[0080] In one embodiment, if the SN needs to configure more than LTMmaxMeasFreqsSCG frequencies, it requests a new LTMmaxMeasFreqsSCG value from the SN. In one embodiment, the SN sends this request to the MN through the CG-Config message. The MN can release some of the frequencies it has configured for the UE for LTM measurements itself and further configure the SN with a new LTMmaxMeasFreqsSCG value as defined above.

[0081] In one embodiment, the MN sets the value of LTMmaxMeasFreqsSCG based on allowedBC-ListMRDC in ConfigRestrictInfoSCG. In one embodiment, the SN configures LTM measurements and LTM candidate cells based on LTMmaxMeasFreqsSCG and maxMeasFreqsSCG and ConfigRestrictInfoSCG.

[0082] In one embodiment, the SN informs the MN about the number of frequencies the UE is configured for LTM measurements.

[0083] In one embodiment, the SN informs the MN about the ARFCN (NR-ARFCN if the SN is a gNB) of the frequencies the UE is configured for LTM measurements. In NR, the SN informs the MN about the number of frequencies the UE is configured for LTM measurements through the INM RRC message CG-Config.

[0084] In one embodiment, the SN informs the MN about the ARFCN of the frequencies the UE is configured for LTM measurements using existing information elements in CG-Config such as measuredFrequenciesSN. The UE includes the ARFCN-ValueNR of the frequencies configured for LTM and L3 measurements in MeasConfigInfo. If the same frequency is configured for both LTM and L3 measurements, they are included only once (i.e. the value is not duplicated).

[0085] An exemplary specification excerpt is given below:

[0086] For example, the measuredFrequenciesSN in TS 38.331 is updated for LTM, where MeasuredFrequenciesSN is used by the SN to indicate the list of frequencies measured by the UE for LTM and L3 measurements.

[0087] In one embodiment, the SN uses a new IE (e.g., LTMmeasuredFrequenciesSN) in CG-Config to inform the UE of the frequencies configured for LTM measurements.

[0088] LTMmeasuredFrequenciesSN can be defined in TS 38.331 as follows.

[0089]

[0090] LTMmeasuredFrequenciesSN is used by the SN to indicate the list of frequencies measured by the UE for LTM measurements.

[0091] MN-SN interaction for LTM is through CG-Config. The SN includes the LTM measurement configuration in CG-Config and sends to the MN.

[0092] The LTM measurement configuration sent from the SN to the MN includes resource configuration such as time domain information (including SMTC information, periodicity, SSB locations in a burst, etc.) and frequency domain information (such as subcarrier spacing, input frequencies). The SN also sends the allowed transmit power to the MN.

[0093] In one embodiment, the MN uses the information received from the above embodiments to configure the measurement gaps, including the measurement gaps required for LTM measurements, the frequencies configured by the MN for LTM and L3 measurements.

[0094] In one embodiment, the MN informs the SN of the frequencies configured for LTM measurements and the frequencies configured for LTM candidate cells through an INM message (such as CG-ConfigInfo).

[0095] In one embodiment, the SN ensures that the total number of frequencies configured for LTM measurements and L3 measurements is less than a constant. In one embodiment, the constant is maxMeasFreqsSN (as defined in TS 38.331 V17.3.0, i.e., 32). If the SN has configured N frequencies for L3 measurements, then the total number of new frequencies (new frequencies refer to frequencies other than the frequencies for which L3 measurements are already configured) configured for LTM by the SN will be less than or equal to N - maxMeasFreqsSN.

[0096] In one embodiment, the SN configures only the frequencies it has configured for L3 measurements as frequencies for LTM measurements.

[0097] In an alternative embodiment, the SN ensures that the total number of frequencies is less than a constant, regardless of the number of frequencies configured for L3 handover. For example, a new constant LTMmaxMeasFreqsSN.

[0098] In one embodiment, the MN ensures that the total number of frequencies configured for LTM measurements and L3 measurements is less than a constant. In one embodiment, the constant is maxMeasFreqsMN (as defined in TS 38.331 V17.3.0, i.e., 32).

[0099] If the MN has configured N frequencies for L3 measurements, the total number of new frequencies (new frequencies refer to frequencies other than the frequencies for which L3 measurements are configured) that the MN configures for LTM will be less than or equal to N - maxMeasFreqsMN.

[0100] In one embodiment, the MN configures only the frequencies it has configured for L3 measurements as frequencies for LTM measurements.

[0101] In one alternative embodiment, the MN ensures that the total number of frequencies is less than a constant, regardless of the number of frequencies configured for L3 handover. For example, LTMmaxMeasFreqsMN.

[0102] In one embodiment, in NR-NR DC or NE-DC, if the UE requires measurement gaps for any LTM measurement (any inter-frequency LTM measurement or any intra-frequency LTM measurement) configured by the SN that requires a gap, the MN configures measurement gaps. The MN decides the gap pattern and gap sharing configuration. The measurement gaps configured in the previous embodiments are gaps according to the UE, according to FR1, or according to FR2. The MN informs the SN of the gaps through RRC INM CG-ConfigInfo. In generating the gaps, the MN also takes into account the measurement gaps required by the UE for any LTM measurement or L3 measurement (any inter-frequency LTM measurement or any intra-frequency LTM measurement) configured by the MN that requires a gap, and the measurement gaps required by the UE for LTM measurements or L3 measurements configured by the SN. The MN also allocates the measurement gaps required by the UE for any LTM measurement configured by the SN.

[0103] In one embodiment, in EN-DC or NG-EN-DC, if the measurement gap required by the UE for any LTM measurement (any inter-frequency LTM measurement or any intra-frequency LTM measurement requiring a gap) configured by the SN is according to the gap of the UE or according to the gap of FR1, the MN decides the gap pattern, gap sharing configuration, etc., and configures the measurement gap. The MN informs the SN about the gap through RRC INM CG-Configlnfo. In generating the gap, the MN also considers the measurement gap required by the UE for any LTM measurement or L3 measurement (any inter-frequency LTM measurement or any intra-frequency LTM measurement requiring a gap according to the gap of the UE or according to the gap of FR1) configured by the MN, and the measurement gap required by the UE for LTM measurement or L3 measurement (requiring a gap according to the gap of the UE or according to the gap of FR1) configured by the SN. If the measurement gap required by the LTM measurement is according to the gap of FR2, the SN decides the gap pattern, gap sharing configuration, etc., configures the measurement gap for the LTM measurement, while considering the measurement gap requirement for any L3 measurement (requiring a gap according to the gap of FR2) configured by the SN. In one embodiment, the MN allocates the measurement gap for the LTM measurement configured by itself.

[0104] In one embodiment, the MN and the SN can not perform any scheduling during the configured measurement gap configured for LTM, that is, the scheduling restriction applies if the LTM measurement is performed in the measurement gap.

[0105] In one embodiment, if the MN configures L3 measurement for the same frequency for which the SN has configured LTM measurement (i.e., the SN configures some LTM candidate cells in the same frequency), the MN and the SN ensure consistency. The MN configures at least one of the same reference signal configuration, the same measurement configuration, the same measurement gap configuration for the L3 measurement it is configuring as configured for the LTM measurement configured by the SN. In one embodiment, the MN and the SN can update the configuration (at least one of the reference signal configuration, the measurement configuration, the measurement gap configuration) to ensure consistency.

[0106] In one embodiment, if the MN configures LTM measurement for the same frequency for which the SN has configured L3 measurement (e.g., the MN configures LTM candidate cells), the MN and the SN ensure consistency. The MN configures at least one of the same reference signal configuration, the same measurement configuration, the same measurement gap configuration for the LTM measurement it is configuring as configured for the L3 measurement configured by the SN. In one embodiment, the MN and the SN can update the configuration (at least one of the reference signal configuration, the measurement configuration, the measurement gap configuration) to ensure consistency.

[0107] In one embodiment, if the SN has configured LTM measurements for the same frequency for which the MN has configured L3 measurements (i.e., the SN has configured some LTM candidate cells in the same frequency), the MN and the SN ensure that both are consistent. The SN configures at least one of the same reference signal configuration, the same measurement configuration, the same measurement gap configuration for the LTM measurements it is configuring as configured by the MN for the L3 measurements. In one embodiment, the MN and the SN can update the configuration (at least one of the reference signal configuration, the measurement configuration, the measurement gap configuration) to ensure that they are consistent.

[0108] In one embodiment, if the SN has configured LTM measurements for the same frequency for which the MN has configured L3 measurements (i.e., the SN has configured some LTM candidate cells in the same frequency), the MN and the SN ensure that both are consistent. The SN configures at least one of the same reference signal configuration, the same measurement configuration, the same measurement gap configuration for the LTM measurements it is configuring as configured by the MN for the L3 measurements. In one embodiment, the MN and the SN can update the configuration (at least one of the reference signal configuration, the measurement configuration, the measurement gap configuration) to ensure that they are consistent.

[0109] In one embodiment, if the MN has configured LTM measurements for the same frequency for which the SN has configured LTM measurements (i.e., the SN has configured some LTM candidate cells in the same frequency), and vice versa, the MN and the SN ensure that both are consistent. The MN configures at least one of the same reference signal configuration, the same measurement configuration, the same measurement gap configuration for the LTM measurements it is configuring as configured by the SN for the LTM measurements (and vice versa). In one embodiment, the MN and the SN can update the configuration (at least one of the reference signal configuration, the measurement configuration, the measurement gap configuration) to ensure that they are consistent.

[0110] In one embodiment, based on the frequency information exchanged between the MN and the SN in some previous embodiments of the present disclosure, the MN and the SN consistently configure the LTM measurements or the L3 measurements. The above embodiments help the MN and the SN ensure that the UE does not perform unnecessary measurements and is not configured with unnecessary measurement gaps.

[0111] In one embodiment, the SN informs the MN of the cells it has configured for LTM. In NR, the SN informs the MN of the candidate cells it has configured for LTM through the CG-Config. An exemplary ASN.1 sequence with respect to TS 38.331 v17.3.0 is given below:

[0112] where maxNrofLTMCells-r18) is the maximum number of LTM candidate cells configured in the UE. In one embodiment, maxNrofLTMCells-r18) is the maximum number of LTM candidate cells configured by the SN. PhysCellld is the physical cell identifier of the candidate cell.

[0113] In one embodiment, the SN informs the MN of the LTM candidate cell configuration of the candidate cells that it has configured to the MN in the CG-Config. In one embodiment, the MN configures the LTM candidate cell, the conditional PSCell change candidate, or the L3 measurement based on the received information about the candidate cell.

[0114] In one embodiment, the MN informs the SN of information such as the NR ARFCN and the physical cell identifier of the cells that it has configured as LTM candidate cells in the SCG. In one embodiment, the MN informs the SN of the LTM measurement configuration, the LTM candidate cell configuration, and other information of the LTM candidate cells that it has configured.

[0115] The present disclosure provides a method and system for performing lower layer (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity. In the present disclosure, a master node (MN) and a secondary node (SN) communicate with each other in order to perform LTM coordination in dual connectivity. The MN transmits frequency information to a secondary node (SN). The SN receives the frequency information and determines configuration information based on the frequency information, and then the SN transmits the configuration information to the MN. The MN determines measurement gaps and LTM candidate cells based on the configuration information. Accordingly, the present disclosure synchronizes the frequencies of the MN and the frequencies configured for the SN based on the measurement gaps. Accordingly, the present disclosure reduces the signaling overhead and the latency problem.

[0116] The following references are made below Figures 1 to 7 Various embodiments of the present disclosure are explained.

[0117] Figure 1An environment for performing lower layer (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity is shown in accordance with embodiments of the present disclosure. The environment 100 includes a master node (MN) 102, a secondary node (SN) 104, and a user equipment (UE) 106. In the present disclosure, the MN 102 and the SN 104 are implemented for the UE 106 for performing lower layer (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity. For example, the MN 102 and the SN 104 can be network nodes for implementing LTM for the UE 106. The UE 106 can be a computing system such as a laptop computer, a desktop computer, a personal computer (PC), a notebook computer, a smartphone, a tablet computer, a server, a network server, a cloud-based server, and the like. The MN 102, the SN 104, and the UE 106 can communicate with each other via a cellular network or a mobile network (also referred to as a radio network distributed in a cellular area).

[0118] In the present disclosure, the MN 102 to which the UE 106 is connected can determine frequency information to be used by the SN 104. The frequency information includes, but is not limited to, at least one of a maximum number of serving frequencies configured by the SN 104 for LTM (such as for LTM measurement and LTM candidate cells) and L3 mobility for the UE 106, a number of frequencies configured by the MN 102 for the UE 106, LTM measurement configuration, secondary cell group (SCG) candidate cells configured by the MN 102 for LTM, and LTM candidate cell configuration for SCG candidate cells configured for the MN 102. The MN 102 can also determine the number of frequencies configured by the MN 102 for the UE 106. In one embodiment, the MN 102 can determine the number of frequencies configured by the MN 102 for the UE 106 based on the UE 106 capability. In another embodiment, the MN 102 can determine the number of frequencies configured by the MN 102 for the UE 106 by considering previous performance of LTM measurement by the MN 102 for the UE 106 and the UE 106 capability. The MN 102 can determine the maximum number of serving frequencies configured by the SN 104 for LTM for the UE 106 based on the number of frequencies configured by the MN 102 for the UE 106 and the UE 106 capability. The maximum number of serving frequencies configured for the SN 104 can be indicated in the field of the IE maximum measurement frequencies secondary cell group (SCG). The maximum number of serving frequencies configured by the SN 104 for LTM and L3 mobility for the UE 106 is determined using one of the maximum measurement frequencies SCG layers including both LTM and L3 mobility and the number of near radio (NR) inter-frequency carriers. The MN 102 can configure the serving frequencies configured for L3 exclusively as frequencies for LTM measurement.

[0119] Further, the MN 102 can transmit an inter-node message including frequency information configured by the SN 104 for the UE 106 for LTM and L3 mobility. The frequency information transmitted from the MN 102 to the SN 104 can include at least one of or a maximum number of serving frequencies, a number of frequencies configured by the MN 102 for the UE 106. The MN can send this information to the SN in an inter-node message. For example, in NR, the inter-node message can be CG-Configlnfo. Further, the frequency information can include at least one of: secondary cell group (SCG) candidate cells configured by the MN 102 for LTM, LTM measurement configuration of the SCG candidate cells configured by the MN 102, and LTM candidate cell configuration. The LTM measurement configuration can include SSB configuration, CSI-RS configuration, SMTC configuration, and the like. In one embodiment, the MN 102 can determine additional information based on the capability of the UE 106 and the number of serving frequencies configured by the MN 102 for the UE 106. In another embodiment, the MN 102 can determine the additional information based on the previous additional information stored in the MN 102.

[0120] The MN 102 can receive the LTM measurement and / or LTM candidate cell information from the SN in an inter-node message. Upon receiving the LTM measurement and / or LTM candidate cell information, the MN 102 can determine the measurement gap and LTM candidate cell configuration of the SN (104). The MN 102 determines the measurement gap and LTM candidate cell configuration of the UE 106 based on the configuration information of the LTM measurement and LTM candidate cells received from the SN 104. Further, the MN 102 can verify whether the measurement gap is compatible based on at least one of a gap pattern, a gap sharing configuration between a maximum number of serving frequencies configured by the SN 104 and a number of frequencies configured by the MN 102. The MN 102 can then transmit the measurement gap and LTM candidate cell configuration to the SN 104 and the UE 106.

[0121] In another embodiment, the SN 104 can receive an inter-node message from the MN 102. The SN 104 associated with the UE 106 receives the inter-node message containing frequency information which the SN 104 uses for the UE 106 for LTM and L3 mobility. The frequency information transmitted from the MN 102 to the SN 104 can include at least one of or a maximum number of serving frequencies, a number of frequencies configured by the MN 102 for the UE 106. Further, the frequency information can include at least one of: secondary cell group (SCG) candidate cells configured by the MN 102 for LTM, LTM measurement configuration of the SCG candidate cells configured by the MN 102, and LTM candidate cell configuration.

[0122] Upon receiving the inter-node message from the MN 102, the SN 104 determines the configuration information. The SN 104 determines at least one configuration information associated with the LTM measurement and the LTM candidate cell based on the inter-node message. The configuration information associated with the LTM measurement and the LTM candidate cell includes at least one of the number of frequencies configured by the UE 106 for the LTM measurement, the absolute radio frequency channel number (ARFCN) of the number of frequencies configured by the UE 106 for the LTM measurement, the subcarrier spacing associated with the number of frequencies configured by the UE 106 for the LTM measurement, the list of LTM candidate cells configured by the UE 106 for the candidate cell, and the LTM candidate cell configuration of the candidate cell. The at least one configuration information associated with the LTM measurement can be received via the CG-Config. The at least one configuration information can include resource configuration, frequency domain information, and allowed transmit power. For example, the resource configuration can include time domain information such as SS / PBCH block measurement timing configuration (SMTC) information, periodicity of frequency signals, location of synchronization signal blocks (SSBs) in a frequency signal burst, and the like. The SMTC information can indicate a network that provides timing of a neighbor cell synchronization signal block (SSB) using SMTC. For example, the frequency domain information can include subcarrier spacing, input frequency, and the like.

[0123] Upon determining the at least one configuration information by the SN 104, the SN 104 can transmit the at least one configuration information to the MN 102. Further, the SN 104 can also transmit the allowed transmit power to the MN 102.

[0124] Upon transmitting the configuration information to the MN 102, the SN 104 can receive the measurement gap and the LTM candidate cell configuration (e.g., configured by the MN) from the MN 102. The SN 104 stores the measurement gap and the LTM candidate cell configuration (e.g., configured by the MN) for the UE 106. The measurement gap can indicate the duration or schedule for the UE 106 to perform any measurement on the resource configuration. Further, during the duration of the measurement gap, the MN 102 and the SN 104 can not perform any scheduling on the UE 106 as scheduling during the duration of the measurement gap can interrupt the measurement performed by the UE 106 on the resource configuration, thereby causing signaling overhead and latency issues. Therefore, the MN 102 transmits the determination of the measurement gap for the UE 106 to the SN 104 in order to synchronize the measurement gap between the serving frequency configured by the SN 104 and the serving frequency configured by the MN 102, thereby reducing the signaling overhead and latency issues. Thus, the present disclosure provides an efficient signaling without causing any latency to the UE 106.

[0125] Figure 2A detailed diagram of a master node for performing lower layer (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity is shown, in accordance with an embodiment of the present disclosure. In one embodiment, master node 202 includes I / O interface 204, memory 204 containing one or more modules 210 and data 208, and processor 206. One or more modules 210 can be configured to perform the steps of the present disclosure using data 208 to perform LTM coordination for UE 106. In one embodiment, each of one or more modules 210 can be a hardware unit that can be located outside of memory 105 and connected with computing system 101. As used herein, the term "module" refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a Field Programmable Gate Array (FPGA), a Programmable System on a Chip (PSoC), a combinational logic circuit, and / or other suitable components that provide the described functionality. One or more modules 210 will form a novel hardware when configured with the described functionality defined in the present disclosure. In one implementation, modules 210 can include, for example, frequency determination module 222, inter-node message transmitting module 224, configuration information receiving module 226, determining module 228, and transmitting module 230. It should be understood that the above modules can be represented as a single module or a combination of different modules. In one implementation, data 201 can include, for example, frequency data 212, inter-node message data 214, configuration information receiving data 216, determining data 218, and transmitting data 220.

[0126] The configuration information receiving data is received from the SN.

[0127] In one embodiment, frequency determination module 222 can be configured to determine frequency information to be used by SN 104. Frequency data 212 can contain the frequency information to be transmitted to SN 104. The frequency information includes at least one of a maximum number of serving frequencies configured by SN 104 for LTM and L3 mobility for UE 106, a number of frequencies configured by MN 102 for the UE, LTM measurement configuration, secondary cell group (SCG) candidate cells configured by MN 102 for LTM, and LTM candidate cell configuration for SCG candidate cells configured for MN 102. Frequency determination module 222 can be configured to determine a maximum number of serving frequencies configured by SN 104 for LTM and L3 mobility for UE 106. Frequency determination module 222 can be configured to determine a number of serving frequencies configured by MN 102 for UE 106. The maximum number of serving frequencies configured by SN 104 is based on a capability of the UE and a number of frequencies configured by MN 102 for the UE. The frequency information can be stored as frequency data 212. For example, referring to Figure 4AThe master node MN 402 can determine a maximum number of serving frequencies configured by the secondary node (SN) 404 for the UE 106. The MN 402 determines a number of serving frequencies configured by the MN 402 for the UE 106. The MN 402 determines the maximum number of serving frequencies configured by the SN 404 for the UE 106 based on the number of serving frequencies configured by the MN for the UE 106 and the capabilities of the UE.

[0128] Referring back Figure 2 The inter-node message transmitting module 224 can transmit an inter-node message. The inter-node message includes frequency information. The frequency information includes at least a maximum number of serving frequencies configured by the SN 104 for the UE 106, a number of frequencies configured by the MN 102, and additional information transmitted to the SN 104. The inter-node message can be stored as inter-node message data 214. Referring back Figure 4A The master node 402 transmits an inter-node message to the SN 404. The inter-node message optionally contains a maximum number of serving frequencies configured by the SN 404 for the UE, a number of serving frequencies configured by the MN 402 for the UE 106, and additional information. In the case that the SN 404 needs to configure more than the maximum number of serving frequencies, the SN 404 can transmit a request for a new value of the maximum number of serving frequencies upon determining that the SN 404 needs to configure more for the UE 106 than the maximum number of serving frequencies received from the MN 402. In this case, the MN 402 can decide to release the new value based on the capability coordination technique.

[0129] In one embodiment, the configuration information receiving module 226 can receive at least one configuration information associated with LTM measurement and LTM candidate cell configured by the SN 104 for the UE 106 based on the inter-node message. The configuration information can be stored as configuration receiving data 216. Referring back Figure 4B The SN 404 determines configuration information based on the inter-node message received from the MN 402. The configuration information associated with LTM measurement and LTM candidate cell includes at least one of: a number of frequencies configured by the SN 404 for the UE 106 for LTM measurement, an absolute radio frequency channel number (such as NR-ARFCN) of the number of frequencies configured by the SN 404 for the UE 106 for LTM measurement, a subcarrier spacing associated with the number of frequencies configured by the SN 404 for the UE 106 for LTM measurement, a list of LTM candidate cells configured by the SN 404 for the UE 106 for candidate cell, and LTM candidate cell configuration of the candidate cell.

[0130] In one embodiment, the determining module 228 determines at least one of a measurement gap and an LTM candidate cell configuration for the UE 106 based on at least one of the LTM measurements received from the SN 104 and the configuration information of the LTM candidate cell. The measurement gap and the LTM candidate cell configuration, among others, can be stored as the determination data 218. Referring back Figure 4B , the MN 402 determines the measurement gap and the LTM candidate cell configured for the UE 106 based on the configuration information received from the SN 404.

[0131] In one embodiment, the transmitting module 230 transmits at least one of the measurement gap and the LTM candidate cell configuration to the SN 104 and the UE. The transmitted measurement gap can be stored as the transmission data 220. Referring back Figure 4C , the MN 402 transmits the configured measurement gap and the LTM candidate cell to the SN 404.

[0132] Referring back Figure 3 , in one embodiment, the secondary node 302 includes an I / O interface 304, a memory 306 containing one or more modules 312 and data 310, and a processor 308. The one or more modules 312 can be configured to perform the steps of the present disclosure using the data 310 to perform LTM coordination for the UE 106. In one embodiment, each of the one or more modules 312 can be a hardware unit that can be located outside the memory 306 and connected with the secondary node 302. As used herein, the term "module" refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a Field Programmable Gate Array (FPGA), a Programmable System on a Chip (PSoC), a combinational logic circuit, and / or other suitable components that provide the described functionality. The one or more modules 312, when configured with the described functionality defined in the present disclosure, will form a novel hardware. In one implementation, the modules 312 can include, for example, a receiving module 320, a configuration information determining module 322, a transmitting module 324. It should be understood that the above-mentioned modules can represent a single module or a combination of different modules. In one implementation, the data 201 can include, for example, a reception data 314, a configuration information determining data 316, a transmission data 318.

[0133] The receiving module 320 receives an inter-node message from the MN 102, the message including frequency information that the SN 104 is to use for LTM and L3 mobility for the UE 106. The received inter-node message information can be stored as the reception data 314. Referring back Figure 4A , the SN 404 receives an inter-node message from the MN 402. The inter-node message can include frequency information that the SN 404 is to use.

[0134] Referring back Figure 3The configuration information determining module 322 determines at least one configuration information associated with the LTM measurement and the LTM candidate cell based on the inter-node message. The configuration information can be stored as configuration information determining data 316. Referring back to Figure 4B The SN 404 determines the configuration information based on the inter-node message received from the MN 402. The configuration information associated with the LTM measurement and the LTM candidate cell includes at least one of the following: a number of frequencies for which the UE 106 is configured for LTM measurement by the SN 404, absolute radio frequency channel numbers (such as NR-ARFCN) of the number of frequencies for which the UE 106 is configured for LTM measurement by the SN (404), subcarrier spacing associated with the number of frequencies for which the UE 106 is configured for LTM measurement by the SN (404), a list of LTM candidate cells for which the UE 106 is configured as candidate cells, and LTM candidate cell configuration of the candidate cells.

[0135] Referring back to Figure 3 The transmitting module 326 transmits the configuration information from the SN 104 to the MN 102. The transmitted configuration data can be stored as transmission data 318. Referring back to Figure 4B The SN 404 transmits the configuration information to the MN 402.

[0136] Referring back to Figure 3 The receiving module 328 receives the measurement gap and the LTM candidate cell configuration from the MN 102. The measurement gap information can be stored as reception data 314. Referring back to Figure 4C The SN 404 receives the measurement gap and the LTM candidate cell configuration from the MN 402. Further, the SN 404 can also send the measurement gap and the LTM candidate cell configuration to the UE 106. Thus, the present disclosure synchronizes the measurement gap between the serving frequencies configured for the SN 404 and the serving frequencies configured for the MN 402. Thus, the present disclosure reduces the signaling overhead and the latency issues.

[0137] Figure 5 An exemplary flow diagram illustrating method steps of a master node for performing lower layer (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity, in accordance with some embodiments of the present disclosure, is shown. As shown, the method 500 can include one or more steps. The method 500 can be described in the general context of computer-executable instructions. Generally, computer-executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform particular functions or implement particular abstract data types. Figure 5

[0138] ​The order in which the method 500 is described is not intended to be limiting, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks can be deleted from the method without departing from the scope of the subject matter described herein. Additionally, the method can be implemented by any suitable hardware, software, firmware, or combination thereof.

[0139] At step 502, the MN 102 associated with the UE 106 determines the maximum number of serving frequencies configured by the SN 104 for the UE for LTM and L3 mobility. The MN 102 determines the number of serving frequencies configured by the MN 102 for the UE 106. The maximum number of serving frequencies configured by the SN 104 for the UE is determined based on the capabilities of the UE 106 and the number of serving frequencies configured by the MN 102 for the UE 106. The serving frequencies configured for L3 measurement by the MN 102 are configured as frequencies for LTM measurement.

[0140] At step 504, the MN 102 transmits an inter-node message to the SN 104, the message including the maximum number of serving frequencies configured by the SN 104 for the UE 106 and the number of frequencies configured by the MN 102. Further, the MN 102 also transmits additional information along with the serving frequencies configured by the SN 104 and the serving frequencies configured by the MN 102 for the UE 106.

[0141] At step 506, the MN 102 receives at least one of the configuration information associated with LTM measurement and LTM candidate cells configured by the SN 104 for the UE 106 via the inter-node message.

[0142] At step 508, the MN 102 determines the measurement gap and LTM candidate cell configuration for the UE 106 based on the configuration information of the LTM candidate cells received from the SN 104.

[0143] At step 510, the MN 102 transmits the measurement gap and LTM candidate cell configuration to the SN 104 and the UE 106 in order to synchronize the measurement gap between the serving frequencies configured for the SN 104 and the serving frequencies configured for the MN 102. Thus, the present disclosure reduces the signaling overhead and latency issues.

[0144] Figure 6 An exemplary flow diagram illustrating method steps of a secondary node for performing lower layer (L1 / L2 layer) triggered mobility (LTM) coordination in dual connectivity, in accordance with some embodiments of the present disclosure, is shown.

[0145] At step 602, the SN 104 associated with the UE 106 receives an inter-node message from a master node (MN) 102 associated with the UE, the message including a maximum number of serving frequencies configured by the SN 104 for the UE 106 for LTM and L3 mobility. Further, the SN 104 can also receive additional information from the MN 102 via the inter-node message. The serving frequencies configured for the SN 104 for L3 measurements are configured as frequencies for LTM measurements.

[0146] At step 604, the SN 104 can determine at least one configuration information associated with LTM measurements and LTM candidate cells based on the inter-node message received from the MN 102.

[0147] At step 606, the SN 104 can transmit the at least one configuration information associated with LTM measurements and LTM candidate cells to the MN 102.

[0148] At step 608, the SN 104 can receive measurement gaps and LTM candidate cell configuration for the UE 106 from the MN 102. The SN 104 configures the measurement gaps for the number of serving frequencies configured by the SN 104 for the UE. Thus, the measurement gaps configured for the serving frequencies of the SN 104 are synchronized with the measurement gaps configured for the serving frequencies of the MN 102. The SN 104 can indicate the measurement gaps for the serving frequencies to the UE.

[0149] The order of the operations of the method 400 and the method 500 need not be performed in the same order as presented. Further, one or more operations can be combined together and performed in the form of a single step, or an operation can contain multiple sub-steps, which can be performed in parallel or in a sequential manner.

[0150] Reference Figure 2 and Figure 3 The disclosed method or reference Figure 5 and Figure 6 One or more operations of the method 500 and 600 can be implemented using software comprising computer-executable instructions stored on one or more computer-readable media (e.g., non-transitory computer-readable media, such as one or more optical discs, volatile memory components (e.g., DRAM or SRAM), or non-volatile memory or storage components (e.g., hard drives or solid-state non-volatile memory components, such as flash memory components)) and executed on a computer (e.g., any suitable computer, such as a laptop computer, netbook, network book, tablet computing device, smartphone, or other mobile computing device). Such software can be executed, for example, on a single local computer.

[0151] Computer system

[0152] Figure 7 A block diagram of an exemplary computer system 701 is shown for implementing embodiments consistent with the present disclosure. In one embodiment, the exemplary computer system 701 can be a master node 102. Thus, the exemplary computer system 701 can be used to communicate with a secondary node 104. The exemplary computer system 701 can include a central processing unit (also "CPU" or "processor"). The processor 706 can include at least one data processor. The processor 706 can include specialized processing units such as integrated system (bus) controllers, memory management control units, floating point units, graphics processing units, digital signal processing units, etc.

[0153] The processor 706 can be configured to communicate with one or more input / output (I / O) devices (not shown) via I / O interface 702. The I / O interface 702 can employ communication protocols / methods such as, but not limited to, audio, analog, digital, mono, RCA, stereo, IEEE (Institute of Electrical and Electronics Engineers)- 1394, serial bus, Universal Serial Bus (USB), infrared, PS / 2, BNC, coaxial, component, composite, Digital Visual Interface (DVI), High-Definition Multimedia Interface (HDMI), radio frequency (RF) antenna, S-Video, VGA, IEEE 802.n / b / g / n / x, Bluetooth, cellular (e.g., Code Division Multiple Access (CDMA), High-Speed Packet Access (HSPA+), Global System for Mobile Communications (GSM), Long-Term Evolution (LTE), WiMax), etc.

[0154] Using the I / O interface 702, the exemplary computer system 701 can communicate with one or more I / O devices. For example, the input device 704 can be an antenna, a keyboard, a mouse, a joystick, an (infrared) remote control, a camera, a card reader, a fax machine, a dongle, a biometric reader, a microphone, a touchscreen, a touchpad, a trackball, a stylus, a scanner, a storage device, a transceiver, a video device / source, etc. The output device 705 can be a printer, a fax machine, a video display (e.g., cathode ray tube (CRT), liquid crystal display (LCD), light-emitting diode (LED), plasma, plasma display panel (PDP), organic light-emitting diode display (OLED), etc.), audio speaker, etc.

[0155] The processor 706 can be configured to communicate with the communication network 708 via the network interface 707. The network interface 707 can communicate with the communication network 708. Connection protocols that the network interface 707 can employ include, but are not limited to, direct connect, Ethernet (e.g., twisted pair 10 / 100 / 1000 Base T), transmission control protocol / internet protocol (TCP / IP), token ring, IEEE 802.11a / b / g / n / x, etc. The communication network 708 can include, but is not limited to, a direct interconnection, a local area network (LAN), a wide area network (WAN), a wireless network (e.g., using Wireless Application Protocol), the Internet, etc. Connection protocols that the network interface 707 can employ include, but are not limited to, direct connect, Ethernet (e.g., twisted pair 10 / 100 / 1000 Base T), transmission control protocol / internet protocol (TCP / IP), token ring, IEEE 802.11a / b / g / n / x, etc.

[0156] The communication network 708 includes, but is not limited to, a direct interconnection, an electronic commerce network, a point-to-point (P2P) network, a local area network (LAN), a wide area network (WAN), a wireless network (e.g., using Wireless Application Protocol), the Internet, Wi-Fi, etc. The first network and the second network can be private networks or shared networks that represent an association of different types of networks that communicate with each other using various protocols (e.g., hypertext transfer protocol (HTTP), transmission control protocol / internet protocol (TCP / IP), wireless application protocol (WAP), etc.). Moreover, the first network and the second network can include various network devices, including routers, bridges, servers, computing devices, storage devices, etc. The master node 102 can receive data (training input data and the plurality of classes) from the neural network over the communication network 708.

[0157] In some embodiments, the processor 706 can be configured to communicate with the memory 715 (e.g., RAM 713, ROM 714, etc.) via the storage interface 712. The storage interface 712 can connect to the memory 715 employing connection protocols, such as serial advanced technology attachment (SATA), integrated drive electronics (IDE), IEEE-1394, universal serial bus (USB), Fibre Channel, small computer system interface (SCSI), etc., that includes, but is not limited to, a memory drive, a removable disk drive, etc. The memory drive can also include a drum, a disk drive, a magneto-optical drive, an optical drive, a redundant array of independent disks (RAID), solid-state memory devices, solid state drives, etc.

[0158] Memory 715 can store a collection of programs or database components, including but not limited to user interface 717, operating system 716, web browser 718, and the like. In some embodiments, example computer system 701 can store user / application data 721, such as data, variables, records, and the like as described in this disclosure. Such databases can be implemented as fault-tolerant, relational, scalable, secure databases such as Oracle® or Sybase®. Memory 715 can be communicatively connected to processor(s) 706. Memory 715 stores instructions executable by one or more processors 706 that, when executed, can cause processor(s) 706 to adapt a neural network to data drift.

[0159] Operating system 716 can facilitate management and operation of resources of example computer system 701. Examples of operating systems include, but are not limited to: APPLE MACINTOSH R , OS X, UNIX R , UNIX-like system distributions (e.g., BERKELEY SOFTWARE DISTRIBUTION TM (BSD), FREEBSD™, NETBSD™, OPENBSD™, etc.), LINUX DISTRIBUTIONS TM (e.g., RED HAT TM , UBUNTU TM , KUBUNTU TM , etc.), IBM TM OS / 2, MICROSOFT TM , WINDOWS TM (XP TM , VISTA TM / 7 / 8, 10, etc.), APPLE R IOS TM , GOOGLE R ANDROID TM , BLACKBERRY R OS, and the like.

[0160] In some embodiments, example computer system 701 can implement web browser 718 storage program component. Web browser 718 can be a hypertext viewing application such as MICROSOFT R INTERNET EXPLORER TM , GOOGLE R CHROME TM0 , MOZILLA R FIREFOX TM , APPLER SAFARI TM Secure web browsing can be provided using Secure Hypertext Transfer Protocol (HTTPS), Secure Sockets Layer (SSL), Transport Layer Security (TLS), etc. The web browser 718 can use AJAX TM 、DHTML TM 、ADOBE R FLASH TM 、JAVASCRIPT TM , JAVA TM , application programming interface (API) and other facilities. In some embodiments, the exemplary computer system 501 can implement a mail server 719 to store program components. The mail server 719 can be an Internet mail server 719, such as Microsoft Exchange. The mail server 719 can utilize a mail server such as ASP.NET. TM ACTIVEX TM , ANSI TM C++ / C#、MICROSOFT R , .NET TM 、CGI SCRIPTS TM , JAVA TM 、JAVASCRIPT TM PERL TM PHP TM 、PYTHON TM 、WEBOBJECTS TM The mail server 719 can utilize facilities such as Internet Message Access Protocol (IMAP), Messaging Application Programming Interface (MAPI), MICROSOFT R Communication protocols such as Exchange, Post Office Protocol (POP), Simple Mail Transfer Protocol (SMTP), etc. In some embodiments, the computer system 501 may implement a mail client 720 stored program component. The mail client (720) may be a mail viewing application such as APPLE R MAIL TM MICROSOFT R ENTOURAGE TM MICROSOFT R OUTLOOK TM 、MOZILLA R Thunderbird TM wait.

[0161] Furthermore, in implementing embodiments consistent with the present disclosure, one or more computer-readable storage media can be utilized. Computer-readable storage media refers to any physical memory of information by a processor 706. Thus, computer-readable storage media can store instructions for execution by one or more processors 706, including instructions for causing a processor 506 to perform steps or stages consistent with the embodiments described herein. The term "computer-readable medium" is understood to encompass tangible objects, and excludes carrier waves and transient signals, i.e., non-transitory. Examples include random access memory (RAM), read-only memory (ROM), volatile memory, non-volatile memory, hard drives, compact discs (CD-ROMs), digital video discs (DVDs), flash drives, magnetic disks, and any other known physical storage media.

[0162] Figure 8 is a block diagram illustrating a structure of a UE according to an embodiment of the present disclosure.

[0163] As Figure 8 indicated, a UE according to an embodiment can include a transceiver 810, a memory 820, and a processor 830. The transceiver 810, the memory 820, and the processor 830 of the UE can operate according to the communication method of the UE described above. However, components of the UE are not limited thereto. For example, the UE can include more or less components than those described above. In addition, the processor 830, the transceiver 810, and the memory 820 can be implemented as a single chip. In addition, the processor 830 can include at least one processor. Furthermore, Figure 8 The UE of Figure 1 corresponds to the UE 106 of Figure 7 .

[0164] The transceiver 810 is collectively referred to as a UE receiver and a UE transmitter, and can transmit / receive a signal to / from a base station or a network entity. The signal transmitted to or received from the base station or the network entity can include control information and data. The transceiver 810 can include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a frequency of a received signal. However, this is only an example of the transceiver 810, and components of the transceiver 810 are not limited to the RF transmitter and the RF receiver.

[0165] In addition, the transceiver 810 can receive and output a signal to the processor 830 through a wireless channel, and transmit a signal output from the processor 830 through a wireless channel.

[0166] The memory 820 can store programs and data required for the operation of the UE. In addition, the memory 820 can store control information or data included in a signal obtained by the UE. The memory 820 can be a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0167] The processor 830 can control a series of processes so that the UE operates as described above. For example, the transceiver 810 can receive a data signal including a control signal transmitted by a base station or a network entity, and the processor 830 can determine a result of receiving the control signal and the data signal transmitted by the base station or the network entity.

[0168] Figure 9 is a block diagram illustrating a structure of a base station according to an embodiment of the disclosure.

[0169] As Figure 9 indicated, the base station according to an embodiment can include a transceiver 910, a memory 920, and a processor 930. The transceiver 910, the memory 920, and the processor 930 of the base station can operate according to the communication method of the base station described above. However, the components of the base station are not limited thereto. For example, the base station can include more or less components than the above-described components. In addition, the processor 930, the transceiver 910, and the memory 920 can be implemented as a single chip. In addition, the processor 930 can include at least one processor. Furthermore, Figure 9 The base station of Figure 1 corresponds to the BS 102 or the BS 104 of Figures 2 to 7 the master node or the secondary node of

[0170] The transceiver 910 collectively refers to a base station receiver and a base station transmitter, and can transmit / receive a signal to / from a terminal (UE) or a network entity. The signal transmitted to or received from the terminal or the network entity can include control information and data. The transceiver 910 can include an RF transmitter for up-converting and amplifying the frequency of a transmission signal, and an RF receiver for low-noise amplifying and down-converting the frequency of a reception signal. However, this is only an example of the transceiver 910, and the components of the transceiver 910 are not limited to the RF transmitter and the RF receiver.

[0171] In addition, the transceiver 910 can receive and output a signal to the processor 930 through a wireless channel, and transmit a signal output from the processor 930 through a wireless channel.

[0172] The memory 920 can store programs and data required for the operation of the base station. In addition, the memory 920 can store control information or data included in a signal obtained by the base station. The memory 920 can be a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0173] The processor 930 can control a series of processes so that the base station operates as described above. For example, the transceiver 910 can receive a data signal including a control signal transmitted by the terminal, and the processor 930 can determine a result of receiving the control signal and the data signal transmitted by the terminal.

[0174] The method according to the embodiments described in the detailed description of the disclosure or claims can be implemented in hardware, software, or a combination of hardware and software.

[0175] When the electrical structure and method are implemented in software, a computer-readable recording medium having one or more programs (software modules) recorded thereon can be provided. The one or more programs recorded on the computer-readable recording medium are configured to be executable by one or more processors in an electronic device. The one or more programs include instructions for performing the methods according to the embodiments described in the detailed description of the disclosure or claims.

[0176] The program (e.g., software module or software) can be stored in a random access memory (RAM), a non-volatile memory including a flash memory, a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic disc storage device, an optical disc-ROM (CD-ROM), a digital versatile disc (DVD), other types of optical storage devices, or a magnetic cassette. Alternatively, the program can be stored in a memory system including a combination of some or all of the aforementioned memory devices. In addition, each memory device can include a plurality of.

[0177] The program can also be stored in an attachable storage device that is accessible through a communication network such as the Internet, an intranet, a local area network (LAN), a wireless LAN (WLAN), or a storage area network (SAN), or a combination thereof. The storage device can be connected to the device according to the embodiments of the disclosure through an external port. Other storage devices on the communication network can also be connected to the device that performs the embodiments of the disclosure.

[0178] In the foregoing embodiments of the disclosure, elements included in the disclosure are expressed in singular or plural form according to the embodiments. However, the singular or plural form is appropriately selected for the convenience of explanation, and the disclosure is not limited thereto. Thus, an element expressed in plural form can also be configured as a single element, and an element expressed in singular form can also be configured as a plurality of elements.

[0179] Although the drawings illustrate different examples of user devices, various changes can be made to the drawings. For example, a user device can include any number of each component in any appropriate arrangement. In general, the drawings do not limit the scope of the disclosure to any particular configuration(s). Moreover, although the drawings illustrate operational environments in which various user device features disclosed in this patent document can be used, these features can be used in any other suitable system.

[0180] At least some of the example embodiments described herein can be constructed, partially or entirely, using dedicated special-purpose hardware. Terms such as “component,” “module,” or “unit” used herein can include, but are not limited to, hardware devices such as circuits in discrete or integrated component form, field-programmable gate arrays (FPGAs), or application-specific integrated circuits (ASICs) that perform certain tasks or provide associated functionality. In some embodiments, the described elements can be configured to reside on a tangible, persistent, addressable storage medium and can be configured to execute on one or more processors. In some embodiments, these functional elements include, for example, components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Although the example embodiments have been described with reference to the components, modules, and units discussed herein, such functional elements can be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features can be combined in any suitable combination. In particular, the features of any one example embodiment can be combined with features of any other embodiments, as appropriate, unless such combinations are mutually inconsistent. Throughout this specification, the term “comprising” or “comprises” means including the specified component but not excluding other components.

[0181] Note that all documents and references cited in this application are hereby incorporated by reference in their entirety for all purposes to the same extent as if each were individually incorporated by reference.

[0182] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings) can be replaced by alternative features that serve the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed in this specification is one example only of a generic series of equivalent or similar features.

[0183] Any feature disclosed in this specification (including any accompanying claims, abstract and drawings) that is not expressly claimed in this specification is provided for the purpose of the reader to fully understand the description of the application as filed.

[0184] The application is not limited to the details of the foregoing embodiments. The application extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel step, or any novel combination of steps, of any method or process so disclosed.

[0185] The present disclosure discloses a method for performing LTM coordination in dual connectivity. The present disclosure determines measurement gaps in frequencies configured for MN and SN. Then, the measurement gaps are synchronized to reduce signaling overhead and latency issues.

[0186] The terms "one embodiment", "an embodiment”, “embodiments”, “the embodiment”, “the embodiments”, “one or more embodiments”, “some embodiments”, and “one embodiment” mean “one or more (but not all) embodiments of the application”.

[0187] The terms “comprise”, “comprising”, “have”, “having”, “include”, “including” and “contain”, “containing” mean “including but not limited to”, unless expressly specified otherwise.

[0188] Enumerated items do not imply that any or all of the items are mutually exclusive, unless expressly stated otherwise. The terms “one”, “a”, and “the” mean “one or more”, unless expressly stated otherwise.

[0189] The description of an embodiment having several components in communication with each other does not imply that all such components are required. To the contrary, a variety of optional components are described to illustrate the wide variety of potential embodiments of the application.

[0190] When a single device or article is described herein, it will be readily apparent that more than one device / article (whether or not they cooperate) can be used in place of a single device / article. Similarly, where more than one device or article is described herein (whether or not they cooperate), it will be readily apparent that a single device / article can be used in place of the more than one device or article or a different number of devices / articles can be used instead of the shown number of devices or programs. The functionality and / or the features of a device can be alternatively embodied by one or more other devices which are not explicitly described as having such functionality / features. Thus, other embodiments of the application need not include the device itself.

[0191] Figure 5 and Figure 6 The operations shown in the figures illustrate certain events occurring in a specific order. In alternative embodiments, certain operations can be performed in a different order, modified or removed. Moreover, steps can be added to the above described logic and still conform to the described embodiments. Further, operations described herein can occur sequentially or certain operations can be processed in parallel. Moreover, operations can be performed by a single processing unit or by distributed processing units.

[0192] Finally, the language used in the specification has been principally selected for readability and instructional purposes and it can not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the application be limited not by this detailed description but rather by any claims that can be drafted, now or in the future, to read on the true spirit and scope of the application. Accordingly, the disclosure of the embodiments of the application is intended to be illustrative, but not limiting, of the scope of the application, which is set forth in the following claims.

[0193] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope being indicated by the following claims.

[0194] The operations can be implemented as a method, system or article of manufacture using standard programming and / or engineering techniques to produce software, firmware, hardware, or any combination thereof. The operations can be implemented as code on a "non-transitory computer-readable medium" which processors can read and execute. A processor is at least one of a microprocessor, and a processor that can process and execute queries. A non-transitory computer-readable medium includes a medium that is not transitory, such as magnetic storage mediums (e.g., hard disk drives, floppy disks, magnetic strips on credit cards, etc.), optical storage mediums (e.g., CD-ROMs, DVDs, optical disks, etc.), volatile and non-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, fash memories, firmware, programmable logic, etc.), etc. In addition, a non-transitory computer-readable medium can include all computer-readable mediums excluding a transitory medium. The code implementing the operations can further be implemented in hardware logic (e.g., an integrated circuit chip, Programmable Gate Array (PGA), Application Specific Integrated Circuit (ASIC), etc.).

[0195] The illustrated steps are intended to explain examples of the illustrated embodiments and are not intended to limit the scope of the described implementations. The continuing technological evolution of hardware and software can modify the manner in which specific functions are performed but such changes, if any, can be incorporated herein by reference. The examples presented herein are presented for illustrative purposes only and are not intended to limit the scope of the described implementations. Moreover, for ease of description, the boundaries of the functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternative boundaries can be defined so long as the specified

[0196] Furthermore, in implementations consistent with the present disclosure, one or more computer-readable storage media can be utilized. Computer-readable storage media refers to any physical storage medium that can store information or data that is readable by a processor. Thus, computer-readable storage media can store instructions for execution by one or more processors including instructions for causing a processor or processors to perform a step or a phase consistent with the embodiments described herein. The term "computer-readable medium" should be taken to include a tangible object and to exclude carrier waves and transient signals, i.e., non-transitory. Examples include random access memory (RAM), read only memory (ROM), volatile memory, non-volatile memory, hard drives, CD-ROMs, DVDs, flash drives, disks, and any other known physical storage media.

[0197] Finally, the language used in the specification is principally intended to be read from a perspective of readability and guidance rather than to delineate or limit the subject matter of the application. Accordingly, the disclosure of embodiments of the present disclosure is intended to be illustrative, and not restrictive, of the scope of the present disclosure.

[0198] As to substantially any plural and / or singular term herein, those having skill in the art can translate from the plural to the singular and / or from the singular to the plural as is applicable to the context and / or application. The various singular / plural permutations can be explicitly set forth herein for sake of clarity.

Claims

1. A method for lower layer (L1 / L2 layer) triggered mobility LTM coordination in dual connectivity performed by a master node MN (102), the method comprising: determining frequency information associated with a terminal (106), said frequency information to be used by a secondary node SN (104) for said terminal (106) for LTM and L3 mobility; transmitting an inter-node message including the frequency information to the SN (104); receiving at least one of configuration information associated with LTM measurement and LTM candidate cells configured for the terminal (106) by the SN (104) based on the inter-node message; determining at least one of a measurement gap and an LTM candidate cell configuration for the terminal (106) based on at least one of the LTM measurement and the configuration information of the LTM candidate cell received from the SN (104); as well as The at least one of the measurement gap and the LTM candidate cell configuration is transmitted to the SN (104) and the terminal (106).

2. The method according to claim 1, wherein The frequency information includes at least one of the following: a maximum number of service frequencies configured by the SN (104) for the LTM, a number of frequencies configured by the MN (102), an LTM measurement configuration, a secondary cell group (SCG) candidate cell configured by the MN (102) for the LTM, and an LTM candidate cell configuration of the SCG candidate cell configured by the MN (102).

3. The method according to claim 1, wherein The configuration information associated with the LTM measurement and the LTM candidate cell includes at least one of the following: the number of frequencies configured by the terminal (106) for the LTM measurement via the SN (104), an absolute radio frequency channel number (ARFCN) of the number of frequencies configured by the terminal (106) for the LTM measurement via the SN (104), a subcarrier spacing associated with the frequencies configured by the terminal (106) for the LTM measurement via the SN (104), a list of the LTM candidate cells configured by the terminal (106) via the SN (104), and the LTM candidate cell configuration of the candidate cells.

4. The method according to claim 1, wherein The maximum number of serving frequencies configured by the secondary node SN (104) for the terminal (106) for LTM measurement and L3 mobility is determined using one of a maximum measurement frequency SCG layer including both the LTM measurement and the L3 mobility and a number of New Radio (NR) inter-frequency carriers.

5. The method according to claim 1, wherein The MN (102) specifically configures the serving frequency configured for the MN (102) for L3 measurement as a frequency for the LTM measurement.

6. A master node for performing lower layer (L1 / L2 layer) triggered mobility LTM coordination in dual connectivity, the master node comprising: transceiver; as well as A controller is connected to the transceiver and is configured to: determining frequency information to be used by a secondary node SN (104) for a terminal (106) for LTM and L3 mobility; transmitting an inter-node message including the frequency information to the SN (104); receiving at least one configuration information associated with LTM measurement and LTM candidate cells configured for the terminal (106) by the SN (104) based on the inter-node message; determining a measurement gap and an LTM candidate cell configuration for the terminal (106) based on the at least one of the LTM measurement and the configuration information of the LTM candidate cell received from the SN (104); as well as The at least one of the measurement gap and the LTM candidate cell configuration is transmitted to the SN (104) and the terminal (106).

7. The master node according to claim 6, wherein: The frequency information includes at least one of the following: a maximum number of service frequencies configured by the SN (104) for the LTM, a number of frequencies configured by the MN (102), an LTM measurement configuration, a secondary cell group (SCG) candidate cell configured by the MN (102) for the LTM, and an LTM candidate cell configuration of the SCG candidate cell configured by the MN (102).

8. The master node according to claim 6, wherein: The configuration information associated with the LTM measurement and the LTM candidate cell includes at least one of the following: the number of frequencies configured by the terminal (106) for the LTM measurement via the SN (104), an absolute radio frequency channel number (ARFCN) of the number of frequencies configured by the terminal (106) for the LTM measurement via the SN (104), a subcarrier spacing associated with the frequencies configured by the terminal (106) for the LTM measurement via the SN (104), a list of the LTM candidate cells configured by the terminal (106) via the SN (104), and the LTM candidate cell configuration of the candidate cells.

9. The master node according to claim 6, wherein: The transceiver determines the maximum number of service frequencies configured by the secondary node SN (104) for the terminal (106) for LTM measurement and L3 mobility by using one of the maximum measurement frequency SCG layer including both LTM measurement and L3 mobility and the number of New Radio NR inter-frequency carriers.

10. The master node according to claim 6, wherein: The transceiver specifically configures the serving frequency configured for the MN (102) for L3 measurement as a frequency for the LTM measurement.

11. A method for lower layer (L1 / L2 layer) triggered mobility LTM coordination in dual connectivity performed by a secondary node SN (104) associated with a terminal (106), the method comprising: receiving an inter-node message from a master node MN (102) associated with the terminal (106), the inter-node message including frequency information used by the SN (104) for LTM measurement and L3 mobility for the terminal (106); determining, based on the inter-node message, at least one configuration information associated with LTM measurements and LTM candidate cells; transmitting the at least one configuration information associated with the LTM and the LTM candidate cell to the MN (102); and A measurement gap and LTM candidate cell configuration of the terminal (106) is received from the MN (102).

12. The method of claim 11, wherein: The frequency information includes at least one of the following: a maximum number of service frequencies configured by the SN (104) for the LTM, a number of frequencies configured by the MN (102), an LTM measurement configuration, a secondary cell group (SCG) candidate cell configured by the MN (102) for the LTM, and an LTM candidate cell configuration of the SCG candidate cell configured by the MN (102).

13. The method of claim 11, wherein: The configuration information associated with the LTM measurement and the LTM candidate cell includes at least one of the following: the number of frequencies configured by the terminal (106) for the LTM measurement via the SN (104), an absolute radio frequency channel number (ARFCN) of the number of frequencies configured by the terminal (106) for the LTM measurement via the SN (104), a subcarrier spacing associated with the frequencies configured by the terminal (106) for the LTM measurement via the SN (104), a list of the LTM candidate cells configured by the terminal (106) via the SN (104), and the LTM candidate cell configuration of the candidate cells.

14. The method of claim 11, wherein: The SN (104) specifically configures the serving frequency configured for the SN (104) for L3 measurement as a frequency for the LTM measurement.

15. A secondary node for performing lower layer (L1 / L2 layer) triggered mobility LTM coordination in dual connectivity, the secondary node comprising: transceiver; as well as A controller is connected to the transceiver and is configured to: receiving an inter-node message from a master node MN (102), the inter-node message including frequency information used by a secondary node SN (104) for the terminal (106); determining, based on the inter-node message, at least one configuration information associated with the LTM and the LTM candidate cell; transmitting at least one of the configuration information associated with LTM measurements and the LTM candidate cells to the MN (102); as well as A measurement gap and LTM candidate cell configuration of the terminal (106) is received from the MN (102).

Images