Method and UE for handling conditional handover in wireless network

Abstract

A method for handling a conditional handover (CHO) by a user equipment (UE) in a wireless network is disclosed. The method may comprise identifying at least one of whether at least one CHO condition for a master cell group (MCG) is satisfied or whether a conditional primary secondary cell (PSCell) addition and change (CPAC) condition for a secondary cell group (SCG) is satisfied; detecting whether a serving cell from the MCG is becoming poor; in case of detecting that the serving cell is becoming poor, identifying that the at least one CHO condition is satisfied and identifying that the CPAC condition is not satisfied, performing a CHO of the serving cell associated with the MCG to a target cell, without waiting for the CPAC condition to satisfy for a SCG candidate cell.

Description

METHOD AND UE FOR HANDLING CONDITIONAL HANDOVER IN WIRELESS NETWORK

[0001] Embodiments disclosed herein relate to a wireless network, and more particularly to methods and a system (or wireless network) for handling a Conditional handover (CHO) accompanied by a Secondary Cell Group (SCG) cell addition within the wireless network.

[0002] As per 3rdGeneration Partnership Project (3GPP) Standard Specification, when a network configures a User Equipment (UE) with candidate target primary secondary cells (PCells) associated with candidate target PSCells, the UE need to evaluate both conditions in parallel and applies target configurations of the PCell and the PSCell simultaneously only when both execution conditions are fulfilled. The existing solution leads to the possibility that the UE will lose a serving cell and results in no service during an PSCell event evaluation though an PCell event gets satisfied when the network configures the UE with the candidate target PCells associated with candidate target PSCells (Conditional handover (CHO) + Conditional PSCell addition (CPAC)). This makes the limitation that though the UE have satisfied the criteria to perform the CHO to a Master Cell Group (MCG) cell, it may lose the serving cell service as it needs to wait to satisfy a criteria for CPA execution (for a SCG cell).

[0003] The CHO, introduced in the 3GPP Release 16 specification, is a handover of a MCG cell connection from a serving cell to a target cell, where the handover is executed by the UE when one or more associated handover execution conditions are met among the multiple candidate cells configured from the network.

[0004] FIG. 1 is a sequence diagram depicting a conditional handover method in a wireless network (100), according to prior arts. In the conditional handover, the network or a gNB prepares a list of CHO candidate cells and sends an RRC reconfiguration message with a list of candidate cells, and associated execution conditions for each of the candidate cells.

[0005] At step 111, a source gNB (104) will send a radio resource control (RRC) connection reconfiguration (CHO configuration) message to the UE (102). At step 112, the UE (102) sends an RRC reconfiguration complete message to the source gNB (104). At step 113, the UE (102) performs a measurement for conditions associated for the CHO. At step 114, the UE (102) starts evaluating CHO candidate cells configured by the network.

[0006] At step 115, once a CHO candidate cell condition criteria is satisfied, the UE (102) performs a downlink (DL) synchronization with the target cell and lose connection to the source gNB (104). At step 116, the UE (102) applies a CHO configuration provided by the source gNB (104) and performs a Random-Access channel (RACH) procedure with the target cell to perform an UL synchronization. At step 117, the UE (102) sends a RRC Reconfiguration complete message to a target gNB (e.g., Target PCell) (106).

[0007] FIG. 2 depicts a conditional PScell event in the wireless network (100), according to prior arts. At step 201, the network or the source gNB (104) prepares a list of CHO and CPA candidate target cells and sends an RRC reconfiguration message to the UE (102) with a list of candidate target cells, and associated execution conditions for each of the candidate target cells.

[0008] At step 202, the UE (102) sends an RRC connection reconfiguration complete message to the source gNB (104) for acknowledgement for the RRC reconfiguration message received. At step 203, the UE (102) performs the measurements for conditions associated for the CHO and the CPAC for the candidate target cells. At step 204, the UE (102) starts evaluating CHO and CPA candidate cells in parallel as configured by the source gNB (104).

[0009] At step 205, once both CHO and CPA candidate cell pair conditions are satisfied, UE (102) performs DL synchronization with the target cell PCell (106) and the target PSCell (108). When the CHO condition gets satisfied and the CPA condition is yet to satisfy, the UE (102) will wait for the CPA connection to get satisfied.

[0010] At step 206, the UE (102) applies the CHO configuration provided by the source gNB (104) and performs a RACH procedure with the target PCell (106) to perform an uplink (UL) synchronization. At step 207, the UE (102) applies the CPA configuration and performs UL / DL synchronization with the target PSCell (108). At step 208, the UE (102) sends an RRC reconfiguration complete message to the target PCell (106) for an acknowledgement of RRC reconfiguration is complete.

[0011] In general, information elements (IEs) for a conditional reconfiguration event, are defined below.

[0012] For conditionalReconfiguration:

[0013] ConditionalReconfiguration-r16 ::= SEQUENCE {

[0014] attemptCondReconfig-r16 ENUMERATED {true}

[0015] OPTIONAL, -- Cond CHO

[0016] condReconfigToRemoveList-r16 CondReconfigToRemoveList-r16 OPTIONAL, -- Need N

[0017] condReconfigToAddModList-r16 CondReconfigToAddModList-r16 OPTIONAL, -- Need N

[0018] ....,

[0019] [[

[0020] scpac-ReferenceConfiguration-r18 SetupRelease {ReferenceConfiguration-r18} OPTIONAL, -- Need M

[0021] servingSecurityCellSetId-r18 SecurityCellSetId-r18

[0022] OPTIONAL, -- Cond condInitialSCPAC

[0023] sk-CounterConfiguration-r18 SK-CounterConfiguration-r18 OPTIONAL -- Need M

[0024] ]]

[0025] }

[0026] For conditional ReconfigToAddmode:

[0027] CondReconfigToAddModList-r16 ::= SEQUENCE (SIZE (1.. maxNrofCondCells-r16)) OF CondReconfigToAddMod-r16

[0028]

[0029] CondReconfigToAddMod-r16 ::= SEQUENCE {

[0030] condReconfigId-r16 CondReconfigId-r16,

[0031] condExecutionCond-r16 SEQUENCE (SIZE (1..2)) OF MeasId OPTIONAL, -- Need M

[0032] condRRCReconfig-r16 OCTET STRING (CONTAINING RRCReconfiguration) OPTIONAL, -- Cond condReconfigAd

[0033] ...,

[0034] [[

[0035] condExecutionCondSCG-r17 OCTET STRING (CONTAINING CondReconfigExecCondSCG-r17) OPTIONAL -- Need M

[0036] ]],

[0037] [[

[0038] condExecutionCondPSCell-r18 SEQUENCE (SIZE (1..2)) OF MeasId OPTIONAL, -- Cond condReconfigCHO-WithSCG

[0039] subsequentCondReconfig-r18 SubsequentCondReconfig-r18 OPTIONAL, -- Need M

[0040] securityCellSetId-r18 SecurityCellSetId-r18

[0041] OPTIONAL, -- Need M

[0042] sCPAc-ConfigComplete-r18 ENUMERATED {true} OPTIONAL -- Cond CPAC

[0043] ]]

[0044] }

[0045] ...

[0046] }

[0047] ConditionalReconfigurationfield descriptions:attemptCondReconfigIf present, the UE shall perform conditional reconfiguration if selected cell is a target candidate cell and it is the first cell selection after failure as described in clause 5.3.7.3.condReconfigToAddModListList of the configuration of candidate SpCells to be added or modified for CHO, CPA or CPC.condReconfigToRemoveListList of the configuration of candidate SpCells to be removed.ConditionalReconfigurationToAddModefield descriptions:condExecutionCondThe execution condition that needs to be fulfilled in order to trigger the execution of a conditional reconfiguration for CHO, CPA, intra-SN CPC without MN involvement, MN initiated inter-SN CPC, or SN initiated intra-SN subsequent CPAC without MN involvement. When configuring 2 triggering events (Meas Ids) for a candidate cell, the network ensures that both refer to the same measObject. The network configures at most one from condEventD1, condEventD2 or condEventT1 for the same candidate cell. For CPA and for MN-initiated inter-SN CPC, the network only indicates MeasId(s) associated with condEventA4. For intra-SN CPC and intra-SN subsequent CPAC, the network only indicates MeasId(s) associated with condEventA3 or condEventA5.condExecutionCondPSCellThe execution condition that needs to be fulfilled for the associated PSCell in order to trigger the execution of a conditional reconfiguration for CHO with candidate SCG(s). The Meas Ids refer to the measConfig associated with the MCG. When configuring 2 triggering events (Meas Ids) for a candidate cell, network ensures that both refer to the same measObject. The network only indicates MeasId(s) associated with condEventA4.condRRCReconfigThe RRCReconfiguration message to be applied when the condition(s) are fulfilled. The RRCReconfiguration message contained in condRRCReconfig cannot contain the field conditionalReconfiguration or the field daps-Config.

[0048] Table 1 shows descriptions of fields of ConditionalReconfiguration.As per 3GPP technical specification (TS) 38.331, the UE (102) can apply the CHO only configuration if provided separately by the network. If the network provides the CHO and CPA configuration, the UE (102) can apply both CHO and CPA configuration once execution conditions associated with both are satisfied.

[0049] As per 3GPP 38.331 V18.1.0, Clause: 5.3.5.13.1 General:The network configures the UE (102) with one or more candidate target SPCells in the conditional reconfiguration. The UE evaluates the condition of each configured candidate target SPCell. The UE (102) applies the conditional reconfiguration associated with one of the target SPCells which fulfils associated execution condition.

[0050] The network can also configure the UE (102) with one or more candidate target PCells associated with one or more candidate target PSCells. The UE evaluates the conditions for the candidate target PCells and the associated candidate target PSCells in parallel and applies a target configuration that include PCell and PSCell for which the associated execution conditions are fulfilled.

[0051] If there are multiple candidate PSCells associated with one candidate target PCell, the network provides multiple conditional configurations for the same candidate target PCell and one of the multiple candidate PSCells associated, i.e., each conditional configuration corresponding to each PSCell of the multiple PSCells, contains one MCG configuration (for the same candidate target PCell) and one same SCG configuration (for one of the multiple associated candidate PSCells).

[0052] For this case, the network may also provide a complementary CHO only configuration, i.e., there is execution condition only for a candidate PCell.

[0053] The UE (102) shall evaluate the conditional reconfiguration provided by the network in a manner as explained in 3GPP TS 38.331 section 5.3.5.13.4. If the conditions incondExecutionCondandcondExecutionCondPSCellis fulfilled, the UE (102) can proceed for conditional reconfiguration execution. (as defined in section 5.3.5.13.5)

[0054] As per, 3GPP TS 38.331, clause 5.3.5.13.4, Conditional reconfiguration evaluation

[0055] The UE (102) shall:

[0056] 1> for each condReconfigId within the VarConditionalReconfig:

[0057] 2> if the RRCReconfiguration within condRRCReconfig includes the masterCellGroup including the reconfigurationWithSync:

[0058] 3> if the associated condExecutionCondPSCell is configured:

[0059] 4> consider the cell which has a physical cell identity matching the value indicated in the ServingCellConfigCommon included in the reconfigurationWithSync within the masterCellGroup in the received condRRCReconfig to be applicable cell; and

[0060] 4> consider the cell which has a physical cell identity matching the value indicated in the ServingCellConfigCommon included in the reconfigurationWithSync within the secondaryCellGroup within the nr-SCG within the received condRRCReconfig to be applicable cell;

[0061] 2> if condExecutionCondPSCell is not configured:

[0062] 2> else:

[0063] 3> if event(s) associated to all measId(s), as indicated in the condExecutionCond and condExecutionCondPSCell, within condTriggerConfig for a target candidate cell within the stored condRRCReconfig are fulfilled:

[0064] 4> consider the target candidate PCell within the stored condRRCReconfig, associated to that condReconfigId, as a triggered PCell;

[0065] 4> consider the target candidate PSCell within the stored condRRCReconfig, associated to that condReconfigId, as a triggered PSCell;

[0066] 4> initiate the conditional reconfiguration execution, as specified in 5.3.5.13.5.

[0067] FIGS. 3-4 are flow diagrams (300-400) illustrating a method for performing a conditional PSCell handover in the wireless network (100), according to prior arts.

[0068] As shown in FIG. 3, at step 302, the method includes configuring, by the network node (or network), CHO + CPAC configuration for the UE (102), where the network node can be a source gNB (104). At step 304, the method includes detecting, by the UE (102), a UE (102)-serving-cell (e.g., source gNB) connection is deteriorating. At step 306, the method includes checking, by the UE (102), if the CHO condition is satisfied.

[0069] At step 308, the method includes checking, by the UE (102), if the CPAC condition is satisfied, once the UE (102) detects that the CHO condition is satisfied. At step 310, the UE (102) waits for at least one of PCell and PScell condition to satisfy and loses serving cell due to poor signal conditions and performs RRE, upon detecting, the CHO condition is not satisfied (at step 306) and the CPAC condition is not satisfied (at step 308). Once the UE (102) detects the CPAC condition is satisfied, at step 312, the method includes applying by the UE (102) the CHO+CPAC configuration and move to a target cell.

[0070] As shown in FIG. 4, at step 402, the method includes configuring, by the UE (102), the serving cell / the source gNB (104) CHO + CPAC configurations (condReconfigId-r16:1) for cell A and cell B, and a CHO configuration (condReconfigId-r16:2) for cell A. At step 404, the method includes detecting, by the UE (102), the UE-serving cell condition is good. At step 406, the method includes, checking by the UE (102), the condition for the CHO if satisfied. At step 408, the UE (102) stays in the UE-serving cell and keeps Evaluating the CHO + CPAC configuration conditions, once the UE (102) detects that, the condition for CHO is not satisfied. Further, at step 410, the method includes, even though the serving-cell connection is good, the UE (102) moves to target PCell but loses Pscell connection, during handover, once the UE (102) detects the CHO condition is satisfied but the CPAC is not satisfied. Therefore, throughput drops at the UE (102).

[0071] In short, the CHO (or MCG cell change), the CPAC (or SCG Addition), the CPC (or SCG Change) are configured as separate conditional events in conditional reconfiguration until 3GPP Release 17. So, the SCG configured in the serving cell will be released during the CHO execution and added by the network separately after the UE (102) completes the conditional handover to a target MCG cell. To overcome the limitation of SCG getting released during the CHO, the conditional PS cell configuration (with CHO configuration along with conditional events) for both configuration are introduced in 3GPP Release 18 specification. As described in FIGS. 4-5, the network can provide the CHO only configuration for the MCG handover, or CHO + CPAC configuration for MCG handover along with SCG addition. As per 3GPP Specification TS 38.331 V18.0.0, "the UE (102) evaluates the conditions for the candidate target PCells and the associated candidate target PSCells in parallel and applies the target configuration that include PCell and PSCell for which the associated execution conditions are fulfilled".

[0072] When the network configures CHO (MCG) + CPAC(SCG) configuration and associated execution conditions, the UE (102) performs measurements for the conditions associated with Conditional handover and Conditional PSCell addition and can apply both configurations simultaneously only when both the associated conditions are satisfied. Due to the 3GPP specification requirement, the UE (102) keeps waiting for execution condition associated with the CPAC to get satisfied and not performing CHO execution even CHO condition is satisfied when the network configures both CHO(MCG) +CPAC(SCG) in a same conditional event. This may be due to PSCell criteria is not getting satisfied, or the associated measurements are not yet performed as it is waiting for next measurement gap etc. The UE (102) may lose the serving cell connection and goes to no service while the UE (102) waits for Conditional PSCell condition to gets satisfied. Though, the CHO candidate condition is satisfied and available for handover, the UE (102) could not perform handover due to 3GPP specification requirement and waits for Conditional PSCell execution and leads to disruption in service continuity. Similarly, as per 3GPP spec 38.331 v18.1.0, section 5.3.5.13.1, for example, the network can configure the CHO and Conditional PSCell configuration for Cell A and Cell B in separate conditional event (Cond event ID 1) and another independent CHO only configuration for Cell A in another conditional event (Cond event ID 2) simultaneously. On CHO event gets satisfied for Cell A, CHO only configuration event (Cond event ID 2) can perform execution and handover to target cell A even though the UE (102) had chance to wait and evaluate Conditional PSCell configuration for cell B and perform both MCG and SCG handover through Cond Event ID 1 even when UE is in good serving cell conditions. On performing CHO handover to target cell A without waiting for Conditional PSCell, the UE (102) loses the chance to add PSCell (SCG) during handover and can leads to throughput drops and impacts user experience.

[0073] FIG. 5 is a sequence diagram illustrating the UE (102) in configured with CHO+CPAC configuration in all CHO candidate cells and the serving cell gets deteriorated, according to prior arts.

[0074] At step 501, the UE (102) is connected to the source gNB (104), and the source gNB (104) configures the UE (102) with RRC reconfiguration (CHO+CPAC configuration condition) for a conditional handover. At step 502, the UE (102) transmits to the source gNB (104), an RRC reconfiguration complete message in order to acknowledge receipt of the RRC reconfiguration conditions. At step 503, the UE (102) performs measurement for conditions associated for the CHO + CPAC. At 504, the UE (102) detects condition associated with PCell is satisfied but condition associated with PSCell is not satisfied. At step 505, the UE (102) loses connection to service gNB (104), while none of the candidate target cell connections are satisfied. At step 506, the UE (102) goes into no service as UE (102)-service cell connection is lost and CHO+CPAC conditions are not satisfied.

[0075] Due to the UE (102) is moving at high speed, and it's serving cell is changing frequently since the signal strength of the serving cell drops as the UE (102) moves away from the cell. The network configures the UE (102) for Conditional Handover and Conditional PSCell addition or change and associated execution conditions. The UE (102) performs measurements for the conditions associated with conditional handover and PSCell addition respectively. The condition for PCell change is satisfied but the condition for the associated PSCell addition is not fulfilled. The PSCell (CPAC) condition could not be satisfied due to multiple factors such as: there may be multiple frequencies to measure, and the CPAC associated frequency could not be measured in the measurement gap, or due to mobility PSCell condition may have deteriorated as well. The UE (102) cannot apply handover configuration till the conditions for both PCell (CHO) and PSCell (CPAC) are not satisfied. Due to UE (102) moving at high speed, the serving cell signal conditions deteriorate quickly and even though target cell PCell conditions are satisfied, the UE (102) cannot handover to target PCell for service continuity and the UE (102) experiences RLF and loss of service waiting for CPAC condition to satisfy. The UE (102) is unable to handover to neighbour cell due to the PSCell addition condition not getting satisfied. The UE (102) loses connection and goes to no service.

[0076] FIG. 6 is a sequence diagram illustrating the UE (102) in configured with CHO+CPAC configuration in CHO candidate cells withattemptcondReconfigFlag and the serving cell gets deteriorated, according to prior arts.

[0077] At step 601, the UE (102) is connected to the source gNB (e.g., UE-serving cell) (104), and the source gNB (104), configures the UE (102) with an RRC Reconfiguration including the CHO + CPAC havingattemptcondreconfigbit set. At step 602, the UE (102) sends an RRC reconfiguration complete message to the source gNB (104), for acknowledging receipt of the RRC reconfiguration conditions. At step 603, the UE (102) performs measurement for the conditions associated for the CHO and CPAC. At step 604, the UE (102) detects that, condition associated with PCell is satisfied but the condition associated with the PSCell is not satisfied and the UE (102) is losing UE-service cell connection fast. At step 605, the UE (102) loses connection to the serving gNB (104), while none of the candidate target cell connections are satisfied. At step 606, the UE (102) goes into no service, as the UE-serving cell condition is lost and the CPAC connections are not satisfied.

[0078] In short, the network has set the bitattemptCondReconfigin ConditionalReconfiguration. The UE (102) performs measurements for the conditions associated with PCell handover and PSCell addition. The UE (102) cannot apply handover configuration till the conditions for the target PCell or PSCell is not satisfied. The condition for the PCell handover or PSCell addition is not satisfied but the UE serving cell measurement is dropping. The execution condition may not be fulfilled as RSRP measured for the cell may not be greater than the value provided by the network in the condition. Since the PCell handover or PSCell addition condition cannot be satisfied, the UE (102) is unable to handover to target cell and it loses connection with the current serving cell due to mobility and goes into no service.

[0079] FIG. 7 is a sequence diagram illustrating the UE (102) in configured with CHO+CPAC configuration and CHO only configuration in CHO candidate cells and the serving cell is NOT deteriorated, according to prior arts.

[0080] At step 701, the UE (102) being served by the Pcell and the PScell. At step 702, the source gNB (104) configures the UE (100), wherein the configuration includes an RRC Reconfiguration (CHO + CPAC) condition for (Cell A+Cell B), and the CHO condition for Cell A. At step 703, the UE (102) transmits an RRC Reconfiguration complete message to the source gNB (104). At step 704, the UE (102) performs measurement for conditions associated for the CHO (Cell A) and CHO + CPAC (Cell A + Cell B). At step 705, the UE (102) detects that the serving PCell and Serving SCell signal is good and condition associated with a target PCell is satisfied but target PSCell is not satisfied. At step 706, the UE (102) handovers to the target PCell and loses serving cell connections, does not wait for the target PSCell condition to get satisfied. At step 707, the UE (102) is now served by target Pcell only. At step 708, the UE (102) loses target PSCell connections even though serving PCell and PSCell connections are good.

[0081] In short, the UE (102) performs the measurements for the conditions associated with PCell handover (Cell A) and Conditional Handover with Conditional PSCell addition or change (Cell A + Cell B). The condition for the PCell handover (Cell A) is satisfied but the condition associated with PCell Handover and PSCell additional (Cell A + Cell B) is not satisfied. The UE (102) applies handover configuration (CHO) for target cell A and handovers to new cell. The UE (102) loses PSCell (secondary cell) during handover as Condition associated with PSCell was not satisfied. Thus, throughput or data speed of the UE (102) is reduced and this results in poor user experience.

[0082] FIG. 8A is a schematic diagram depicting the UE (102) attempting a conditional PCell and a conditional PSCell handover, according to prior arts. As per 3GPP standard specification, when the network configures the UE (102) with a plurality of candidate target PCells associated with the plurality of candidate target PSCells, the network configures the CHO and the CPAC for the UE (102) attempting for the conditional handover to the plurality of candidate target PCells and the plurality of candidate target PSCells). The UE (102) evaluates both CHO and CPAC execution conditions in parallel and applies the plurality of target configurations for the plurality of candidate target PCells and the plurality of candidate target PSCells simultaneously only when the both execution conditions are fulfilled.

[0083] This existing limitation makes the UE (102) to lose connection with the UE (102) and a serving cell and results in no service during an PScell event evaluation though the PCell event gets satisfied. This makes the limitation that though the UE (102) have satisfied the criteria to perform CHO to a candidate target MCG cell, the UE (102) may lose the candidate target MCG cell service as it needs to wait to satisfy the criteria for CPA execution for an SCG cell. Conditional PSCell (CPAC) introduced in Release 18 to address the limitation of an SCG getting released / not added during CHO but it brings additional limitation of the UE (102) waits for conditional PScell event to be fulfilled even when a CHO event with the PCell is satisfied and when the UE (102) is configured with CHO(MCG)+CPAC(SCG) configurations for a plurality of candidate target cells.

[0084] FIG. 8B is an example scenario (800B) in which the UE (102) in configured with CHO+CPAC configuration in the CHO candidate cells withattemptcondReconfigFlag and serving cell gets deteriorated, according to prior arts. At T1, UE is connected to PCell. Network configured CHO configuration.attemptCondReconfigbit is set. At T2, the UE is waiting for CHO condition to get satisfied. UE's serving cell condition is getting poorer. At T3, UE keeps waiting for CHO condition to get satisfied. UE loses serving cell and experiences RLF.

[0085] FIG. 9A illustrate an overall system diagram along with a graph (900A) depicting the conditional handover of the UE (102) configured with CHO+CPAC configuration and CHO only configuration in CHO candidate cells and the serving cell is NOT deteriorated, according to prior arts. FIG. 9B depicts a graphical presentation (900B) of throughput (Y) of the UE calculated with respect to time (X), according to prior arts.

[0086] The condition associated with the CHO is satisfied but condition for CPAC (e.g., condReconfigId-r16: 1) is not satisfied. The UE (102) applies the CHO only configuration (condReconfigId-r16: 2) and handovers to target PCell. Hence, the UE (100) loses the PSCell connection during handover. Throughput drops from 300 mbps to 100 mbps (for example).

[0087] Hence, there is a need in the art for solutions which will overcome the above mentioned drawback(s), among others.

[0088] An object of embodiments herein is to disclose a method and a UE for handling of a CHO in a wireless network.

[0089] An object of embodiments herein is to utilize an optimization technique to make a decision of performing execution between a combination of a CHO (i.e., MCG) and Conditional PScell (i.e., SCG) configuration or CHO (MCG) only configuration based on a serving cell signal condition calculated by at least one pre-determined factor (e.g., parameter) to retain the service continuity and seamless data connectivity.

[0090] An object of embodiments herein is to utilize an optimization technique for the UE to perform CHO and move to an MCG target cell and send a SCG failure information report without waiting for Conditional PS cell evaluation completion during deterioration of serving cell when the UE is configured with both MCG configuration and SCG configuration in at least one conditional event in the Conditional Reconfiguration to retain the service continuity.

[0091] An object of embodiments herein is to wait for conditional event with both CHO (MCG) and Conditional PScell (SCG) configuration gets satisfied where the UE doesn't apply conditional reconfiguration of standalone CHO event until the UE serving cell is in good condition and not deteriorated even when a standalone CHO event criteria satisfied to make seamless data connectivity.

[0092] An object of embodiments herein is to utilize an optimization technique for the UE to perform the CHO and move to an MCG target cell without waiting for Conditional PS cell evaluation completion during deterioration of the serving cell when the UE is configured with both MCG and SCG configuration in the at least one conditional event along with anattemptCondReconfig flagin the Conditional Reconfiguration to retain the service continuity.

[0093] An object of embodiments herein is to disclose that the proposed method ensures that the UE won't lose the serving cell and no service due to the UE waiting for the Conditional PS cell evaluation event completion though the CHO event criteria gets satisfied which enhances service continuity. The proposed method also increases the chance for UE to transits both MCG and SCG connection simultaneously when a serving cell condition of the UE is good which enhances data throughput and enriches user experience.

[0094] According to an embodiment of the present disclosure, a method for handling a conditional handover (CHO) by a user equipment (UE) in a wireless network is provided. The method may comprise identifying at least one of whether at least one CHO condition for a master cell group (MCG) is satisfied or whether a conditional primary secondary cell (PSCell) addition and change (CPAC) condition for a secondary cell group (SCG) is satisfied. The method may comprise detecting whether a serving cell from the MCG is becoming poor. The method may comprise in case of detecting that the serving cell is becoming poor, identifying that the at least one CHO condition is satisfied and identifying that the CPAC condition is not satisfied, performing a CHO of the serving cell associated with the MCG to a target cell, without waiting for the CPAC condition to satisfy for a SCG candidate cell.

[0095] The method may comprise in case of detecting that the serving cell is becoming poor, identifying that the at least one CHO condition is satisfied and identifying that the CPAC condition is satisfied, applying a target cell configuration and moving to the target cell.

[0096] The method may comprise in case of detecting that serving cell is not becoming poor, identifying that the at least one CHO condition is satisfied and identifying that the CPAC condition is not satisfied waiting for the CPAC condition is not satisfied to be satisfied while staying in the serving cell.

[0097] The method may comprise transmitting a SCG failure information message without waiting for a conditional PS cell evaluation completion during deterioration of the serving cell when the UE is configured with both a CHO configuration and an CPAC configuration.

[0098] The SCG failure information message may be transmitted to the target cell after sending an RRC reconfiguration complete message to the target cell after applying the CHO configuration without applying the CPAC configuration.

[0099] The method may comprise performing the CHO and moving to an MCG target cell without waiting for conditional PS cell evaluation completion during deterioration of the serving cell, in case that the UE is configured with both an MCG configuration and a SCG configuration along with an attemptCondReconfig flag in a conditional reconfiguration.

[0100] The UE may be connected to both MCG and SCG and receives a standalone CHO configuration from the wireless network. The UE may handover to the target cell and a target PSCell in case that the at least one CHO condition for the MCG is satisfied and the SCG is not satisfied, when the UE waits for at least one conditional event with an MCG configuration and an SCG configuration that are satisfied. The UE may not apply the conditional reconfiguration of the standalone CHO event until the serving cell of the UE is in the service condition and not deteriorated.

[0101] Identifying at least one of whether at least one CHO condition for the MCG is satisfied or whether the SCG is satisfied may comprise, receiving a radio resource control (RRC) reconfiguration comprising a CHO and　CPAC from a network entity; sending, a RRC reconfiguration complete to the network entity; and performing a measurement for a condition associated for the CHO and CPAC.

[0102] Identifying at least one of whether at least one CHO condition for the MCG is satisfied or whether the SCG is satisfied may comprise, receiving a RRC reconfiguration comprising a CHO and CPAC from a network entity, wherein the RRC reconfiguration comprises an attempt configuration bit; sending a RRC reconfiguration complete to the network entity; and performing a measurement for a condition associated for the CHO and CPAC.

[0103] Applying the target cell configuration and moving to the target cell may comprise, declaring a failure on a service cell of the UE; applying a conditional reconfiguration as attemptcondReconfig bit is set; and applying the target cell configuration and moving to the target cell.

[0104] The UE may detect that the serving cell is going to no service mode based on at least one parameter. The at least one parameter may comprise at least one of: a Reference Signal Received Power (RSRP) level of a serving cell below a certain threshold, a change in the RSRP level with respect to a time, a change in the RSRP level with respect to a movement of the UE, a Block Error Rate (BLER) value for a Pcell, a change in the BLER rate with respect to a time, a change in the BLER rate with respect to a movement of the UE, a Signal to Interference Noise Ratio (SINR) value, a Physical Downlink Control Channel (PDCCH) decoding failure rate, or a Physical Downlink Shared Channel (PDSCH) decoding failure rate.

[0105] The UE may detect that the serving cell is going to no service mode based on at least one of: a data driven module, a Radio Link Failure　(RLF)　failure stored in a memory or a Secondary Cell Group (SCG) failure stored in the memory.

[0106] The UE may handles the CHO when the UE is configured in the MCG and the SCG in the wireless network, wherein the target cell is at least one of: a target PCell and a target PSCell.

[0107] According to an embodiment of the present disclosure, a user equipment (UE) for handling a conditional handover (CHO) in a wireless network is provided. The UE may comprise memory (1830) storing instructions and at least one processor. The instructions, when executed by the at least one processor, may cause the UE to perform operations. The operations may comprise identifying at least one of whether at least one CHO condition for a master cell group (MCG) is satisfied or whether a conditional primary secondary cell (PSCell) addition and change (CPAC) condition for a secondary cell group (SCG) is satisfied. The operations may comprise detecting whether a serving cell from the MCG is becoming poor. The operations may comprise in case of detecting that the serving cell is becoming poor, identifying that the at least one CHO condition is satisfied and identifying that the CPAC condition is not satisfied, performing a CHO of the serving cell associated with the MCG to a target cell, without waiting for the CPAC condition to satisfy for a SCG candidate cell.

[0108] According to an embodiment of the present disclosure, a non-transitory computer readable storage medium storing instructions is provided. The instructions which, when executed by at least one processor of a user equipment (UE), may cause the UE perform operations. The operations may comprise identifying at least one of whether at least one CHO condition for a master cell group (MCG) is satisfied or whether a conditional primary secondary cell (PSCell) addition and change (CPAC) condition for a secondary cell group (SCG) is satisfied. The operations may comprise detecting whether a serving cell from the MCG is becoming poor. The operations may comprise in case of detecting that the serving cell is becoming poor, identifying that the at least one CHO condition is satisfied and identifying that the CPAC condition is not satisfied, performing a CHO of the serving cell associated with the MCG to a target cell, without waiting for the CPAC condition to satisfy for a SCG candidate cell.

[0109] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating at least one embodiment and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

[0110] Embodiments herein are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the following illustratory drawings. Embodiments herein are illustrated by way of examples in the accompanying drawings, and in which:

[0111] FIG. 1 is a sequence diagram depicting a conditional handover method in a wireless network, according to prior arts.

[0112] FIG. 2 depicts a conditional PScell event in the wireless network, according to prior arts.

[0113] FIGS. 3-4 are flow diagrams illustrating a method for performing a conditional PSCell handover in the wireless network, according to prior arts.

[0114] FIG. 5 is a sequence diagram illustrating the UE in configured with CHO+CPAC configuration in all CHO candidate cells and a serving cell gets deteriorated, according to prior arts.

[0115] FIG. 6 is a sequence diagram illustrating the UE in configured with CHO+CPAC configuration in CHO candidate cells withattemptcondReconfigFlag and the serving cell gets deteriorated, according to prior arts.

[0116] FIG. 7 is a sequence diagram illustrating the UE in configured with CHO+CPAC configuration and CHO only configuration in the CHO candidate cells and the serving cell is not deteriorated, according to prior arts.

[0117] FIG. 8A is a schematic diagram depicting the UE attempting a conditional PCell and a conditional PSCell handover, according to prior arts.

[0118] FIG. 8B is an example scenario in which the UE in configured with CHO+CPAC configuration in the CHO candidate cells withattemptcondReconfigFlag and serving cell gets deteriorated, according to prior arts.

[0119] FIG. 9A illustrate an overall system diagram along with a graph depicting the conditional handover of the UE configured with CHO+CPAC configuration and CHO only configuration in the CHO candidate cells and the serving cell is not deteriorated, according to prior arts.

[0120] FIG. 9B depicts a graphical presentation of throughput (in Y axis) of the UE calculated with respect to time (in X axis), according to prior arts.

[0121] FIG. 10 depicts a sequence diagram of the method for optimizing the conditional handover of the UE, form a serving cell to a target cell, while the serving cell (e.g., gNB or the like) connection is getting deteriorated, according to embodiments as disclosed herein.

[0122] FIG. 11 is a sequence diagram illustrating the UE in configured with CHO+CPAC configuration in the CHO candidate cells withattemptcondReconfigFlag and the serving cell gets deteriorated, according to embodiments as disclosed herein.

[0123] FIG. 12 depicts the method for optimizing conditional handover of the UE to a plurality of target cells with CHO+CPAC configuration conditions, when the serving cell connection is not deteriorating, according to embodiments disclosed herein.

[0124] FIG. 13 depicts the flow diagram of a method for handling the conditional handover with the PCell and the PSCell, according to embodiments as disclosed herein.

[0125] FIG. 14 depicts the flow diagram of the method for handling the conditional handover of the UE to the at least one target cell, by optimizing the CHO for the cell A (e.g., Pcell) and the CPAC for the cell B (e.g., PScell), according to embodiments as disclosed herein.

[0126] FIG. 15 is a flow diagram for a method of handling a conditional handover of the UE to a target PCell, wherein the UE satisfies only CHO configuration condition of a CHO+CPAC configuration condition for the conditional handover, provided by the UE-serving cell, according to embodiments as disclosed herein.

[0127] FIG. 16 and FIG. 17 are flow charts illustrating the method for handing of Conditional PS cell configuration for service continuity and higher throughput, according to embodiments as disclosed herein.

[0128] FIG. 18 shows various hardware components of the UE, according to embodiments as disclosed herein.

[0129] FIG. 19 is a flow chart illustrating the method of handling the CHO and the CPAC conditions on the candidate cell in the wireless network, according to embodiments as disclosed herein.

[0130] FIG. 20A is the schematic diagram depicting a UE attempting a conditional PCell and the conditional PSCell handover in a network, according to embodiments as disclosed herein.

[0131] FIG. 20B depicting a graph the UE in configured with the CHO+CPAC configuration in all CHO candidate target cells and serving cell gets deteriorated, according to embodiments as disclosed herein.

[0132] FIG. 20C is a schematic diagram depicting the UE in configured with CHO+CPAC configuration for a conditional handover in CHO candidate cells withattemptcondReconfigFlag and UE-serving cell connection is getting deteriorated, according to embodiments as disclosed herein.

[0133] FIG. 21A depicts the schematic diagram of the system for optimizing a conditional handover of the UE configured by a network node (UE-serving cell) with CHO+CPAC configuration and CHO only configuration in CHO candidate cells and serving cell is NOT deteriorated, according to embodiments disclosed herein.

[0134] FIG. 21B depicts the comparison graphical presentation of a throughput (shown in Y axis) with time (shown in X axis) for the proposed condition handover method and prior arts.

[0135] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0136] For the purposes of interpreting this specification, the definitions (as defined herein) will apply and whenever appropriate the terms used in singular will also include the plural and vice versa. It is to be understood that the terminology used herein is for the purposes of describing particular embodiments only and is not intended to be limiting. The terms "comprising", "having" and "including" are to be construed as open-ended terms unless otherwise noted.

[0137] The words / phrases "exemplary", "example", "illustration", "in an instance", "and the like", "and so on", "etc.", "etcetera", "e.g.," , "i.e.," are merely used herein to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the present subject matter described herein using the words / phrases "exemplary", "example", "illustration", "in an instance", "and the like", "and so on", "etc.", "etcetera", "e.g.," , "i.e.," is not necessarily to be construed as preferred or advantageous over other embodiments.

[0138] Embodiments herein may be described and illustrated in terms of blocks which carry out a described function or functions.　These blocks, which may be referred to herein as managers, units, modules, hardware components or the like, are physically implemented by analog and / or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits and the like, and may optionally be driven by a firmware. The circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like.　The circuits constituting a block may be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block.　Each block of the embodiments may be physically separated into two or more interacting and discrete blocks without departing from the scope of the disclosure.　Likewise, the blocks of the embodiments may be physically combined into more complex blocks without departing from the scope of the disclosure.

[0139] It should be noted that elements in the drawings are illustrated for the purposes of this description and ease of understanding and may not have necessarily been drawn to scale. For example, the flowcharts / sequence diagrams illustrate the method in terms of the steps required for understanding of aspects of the embodiments as disclosed herein. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the present embodiments so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Furthermore, in terms of the system, one or more components / modules which comprise the system may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the present embodiments so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

[0140] The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any modifications, equivalents, and substitutes in addition to those which are particularly set out in the accompanying drawings and the corresponding description. Usage of words such as first, second, third etc., to describe components / elements / steps is for the purposes of this description and should not be construed as sequential ordering / placement / occurrence unless specified otherwise.

[0141] In this disclosure "UE-serving cell", "serving gNB", "serving network node", "source gNB", are used interchangeably. Further, "target cell", "candidate target cell", "candidate target gNB", "target gNB", "MCG target cell" are used interchangeably.

[0142] The embodiments herein achieve methods and a UE for handling handover with conditional PCell and PSCell. In detail, the method can be used for handling a CHO in a wireless network. The wireless network can be, for example, but not limited to a fourth generation (4G) network, a fifth generation (5G) network, a 6G network, an Open Radio Access Network (ORAN) or the like. The method includes evaluating, by a UE, whether at least one CHO condition for a Master Cell Group (MCG) is satisfied and a CPAC condition for Secondary Cell Group (SCG) is not satisfied. Further, the method includes detecting, by the UE, whether an MCG cell is going to poor signal (may lose serving cell service) based on the evaluation. In an embodiment, the method includes performing a conditional handover of the MCG to a target cell upon detecting that the MCG cell is deteriorating and becoming poor (may lose serving cell service). In an embodiment, the method includes applying CHO configuration to satisfied target cell and moving to the target cell upon detecting that the MCG cell is becoming poor without waiting for CPAC for SCG to be satisfied. In an embodiment, the method includes waiting for at least one conditional event with an MCG configuration and a SCG configuration that are satisfied, wherein the UE does not apply a conditional reconfiguration of a standalone CHO event until a serving cell of the UE is in a service condition and the serving cell has not deteriorated. Further, the method includes retaining, by the UE, at least one of: a service continuity and a data connectivity.

[0143] The proposed method can be used to ensure that the UE performs execution between CHO (MCG)+CPAC (SCG) configuration or CHO (MCG) only configuration based on the serving cell signal condition decided by various factors to retain the service continuity and seamless data connectivity and enhance a user experience.

[0144] The proposed method would ensure that the UE performs CHO and moves to MCG target cell without waiting for Conditional PS cell evaluation completion during deterioration of serving cell when the UE is configured with both MCG and SCG configuration in conditional events in the Conditional and reconfiguration which makes the UE reduce the chance of losing the service and disruption in the user connectivity and thus increase the chance to maintain service continuity of the UE.

[0145] The proposed method would ensure that the UE will wait for conditional event with both CHO(MCG) and CPAC(SCG) configuration gets satisfied and doesn't apply conditional reconfiguration of a standalone CHO event even when a standalone CHO event criteria satisfied until the serving cell of the UE is in good condition when the UE is configured with both CHO+CPAC combination event and CHO standalone event which increase the probability to maintain SCG connection during Handover and so UE performs seamless data connectivity and maintain the data throughput which enhances the data performance of the UE.

[0146] The proposed method can be used to maintain the service continuity when the UE is configured with CHO(MCG)+CPAC(SCG) candidate cells configuration in the UE and improves data performance and enhance user experience.

[0147] Referring now to the drawings, and more particularly to FIGs. 10 through 21B, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.

[0148] FIG. 10 depicts a sequence diagram of the method for optimizing the conditional handover of the UE (102), form a serving cell to a target cell, while the serving cell (here a gNB) connection is getting deteriorated, according to embodiments as disclosed herein. The UE (102) and the network (1002) support the conditional handover, and conditional PSCell addition or conditional PSCell change. When the UE (102) is moving at high speed within the geographical area, the serving cell of the UE (102) is changing frequently since the signal strength of the serving cell drops as the UE (102) moves away from the cell.

[0149] At step 1001, the network node (104) (here gNB) configures the UE (102), with the RRC reconfiguration along with the CHO+CPAC conditions, for accessing the target gNB cell. The network node can be, for example, but not limited to a serving gNB, a serving eNB, a serving new radio (NR) trans-receiver or the like. The serving gNB (104), reconfigures the UE (102) for the conditional handover and the conditional pscell addition (or the conditional PSCell change) and associated execution conditions (CHO+CPAC conditions). In an embodiment herein, the serving gNB (104) sends the RRC reconfiguration message to the UE (102), where the RRC reconfiguration message includes a plurality of associated execution conditions (e.g., CHO+CPAC conditions) for the conditional handover.

[0150] At step 1002, the UE (102) sends an RRC reconfiguration complete message for an acknowledgement of receiving the RRC reconfiguration along with CHO+CPAC conditions to the gNB (104). At step 1003, the UE (102) performs measurements for the plurality of associated execution conditions (e.g., CHO+CPAC conditions) for the PCell change and the PSCell addition.

[0151] At step 1004, the UE (102) detects that, the condition for the PCell change is satisfied but the condition for the associated PSCell addition is not fulfilled. In an embodiment herein, the UE (102) can predict the possibility for satisfaction of condition for the CPAC reconfiguration corresponding to handover to the target cell, based on monitoring RSRP value, the RSRQ value, the BLER, and the SINR corresponding to the target PSCell for a predetermined period of time

[0152] At step 1005, the UE (102) observes that the serving cell signal strength is deteriorating fast and the UE measures the plurality of pre-determined factors for example the RSRP levels of the UE-serving cell below the certain threshold, a change in the RSRP level with respect to time, a change in RSRP level with respect to a per distance movement of the UE in a geographic location, the BLER value for the PCell, Change in the BLER rate with respect to time, the change in the BLER rate with respect to the a per distance movement of the UE (102) in the geographic location, the SINR value, and PDCCH / PDSCH decoding failure rate, and so on to predict losing of serving gNB (104) connection.

[0153] At step 1006, the UE (102) applies the target Pcell configuration and moves to the target PCell. At step 1007, the UE (102) sends an RRCReconfiguration complete message to the target PCell (106), upon accessing the target PCell. At step 1008, after moving to the target PCell, the UE (102) immediately sends at least an SCG FailureInformation to the target PCell (106) to declare PSCell (SCG) addition failure. At step 1009, the UE (102) is moved to the target PCell before losing the UE-serving cell connection.

[0154] FIG. 11 is a sequence diagram illustrating the UE in configured with CHO+CPAC configuration in CHO candidate cells with attemptcondReconfig Flag and serving cell gets deteriorated, according to embodiments as disclosed herein.

[0155] At step 1101, the serving gNB (104) configures the UE (102), with an RRC reconfiguration including attemptcondreconfig bit set, along with CHO+CPAC, for accessing the target cell. The serving gNB (1006), configures the UE (102) for at least a Conditional Handover and a Conditional PSCell addition (a Conditional PSCell change) and associated execution conditions (CHO+CPAC conditions). In an embodiment herein, the serving gNB (Ue-serving cell) sends to the UE (102), an RRC reconfiguration message comprising a plurality of associated execution conditions (CHO+CPAC conditions) for the Conditional Handover.

[0156] At step 1102, the UE (102) sends, to the gNB (104), an RRC reconfiguration complete message for an acknowledgement of receiving the RRC reconfiguration along with CHO+CPAC conditions. At step 1103, the UE (102) performs measurements for the plurality of associated execution conditions (e.g., CHO+CPAC conditions) for the PCell change and the PSCell addition respectively.

[0157] At step 1104, the UE (102) detects that, the condition for the PCell change is satisfied but the condition for the associated PSCell addition is not fulfilled and the UE (102) is loosing UE-service cell connection fast. In an embodiment herein, the UE (102) is loosing UE-service cell connection fast, due to a plurality of factors as stated earlier in this document such as, deteriorating SINR, increasing BLER value, and so on. Further, the UE (102) can predict using the AI and ML engine, that, the CPAC condition will be unachieved due to the plurality of network parameters attaining respective threshold values, wherein the plurality of network parameters are stated earlier in this document hence, for the sake of clarity, we are not repeating the same.

[0158] At step 1105, the UE (102) declares failure on the UE-service cell i.e. the serving gNB (104) and applies conditional reconfig as attemptcondReconfig bit is set. At step 1106, upon measuring the plurality of factors, if the UE (102) determines it may lose serving cell, the UE (102) applies only the CHO part present in ConditionalReconfiguration of the CHO + CPAC configuration and moves to a target PCell (106).

[0159] In an embodiment, the UE (102) can apply the CHO configuration for PCell after internally declaring service loss on current cell as the attemptCondReconfig bit is set in the CHO configuration provided by the gNB.

[0160] At step 1107, the UE (102) sends an RRCreconfiguration complete message to the target PCell, upon accessing the target PCell. At step 1108, the UE (102) moves to the target PCell while the target PSCell condition is not satisfied. Therefore, the UE (102) is served by the target PCell (106) only.

[0161] FIG. 12 depicts the method for optimizing conditional handover of the UE (102) to a plurality of target cells with CHO+CPAC configuration conditions, when the serving cell connection is not deteriorating according to embodiments disclosed herein. The UE (102) and a Network (1002) support Conditional handover and Conditional Handover along with Conditional PSCell addition or change. The UE (102) stationery and it's serving PCell and serving PSCell provide good service.

[0162] At step 1201, the Network (a serving PCell and a serving PSCell) configures the UE (102) for Conditional Handover for a target PCell (cell A) and associated execution conditions. Further, the network (a serving PCell and a serving PSCell) also configures the UE (102) with an RRCreconfiguration message for Conditional Handover with associated Conditional PSCell addition in relation to handover to the target PCell A and PSCell B.

[0163] At step 1202, The UE (102) sends an RRCReconfiguartion complete message to the network (a serving PCell and a serving PSCell) as an acknowledgement of receiving by the UE (102) the RRCReconfigutation.

[0164] At step 1203, the UE (102) performs measurements for the conditions associated with, CHO only configuration (CellA) (condReconfigId-r16:1) and Conditional Handover with Conditional PSCell addition or change (Cell A and Cell B) (condReconfigId-r16: 2).

[0165] At step 1204, the UE (102) determines that, the serving PCell (1010) and the serving PSCell (1014) is good, and the condition for PCell handover (condReconfigId-r16: 1) is satisfied but the condition associated with PCell Handover and PSCell additional (condReconfigId-r16: 2) is not satisfied. In an embodiment herein, the UE (102) measures the plurality of pre-determined factors as stated earlier in order to determine if it may lose serving cell or not, since the UE (102) serving PCell and PSCell are in good signal condition.

[0166] At step 1205, the UE (102) waits for target PSCell condition to satisfy before a handover. Further, the UE (102) remains with the current serving cell until the PSCell condition is satisfied or, the serving PCell and the serving PSCell conditions become poor.

[0167] At step 1206, once the PSCell condition is satisfied, the UE (102) applies CHO+CPAC configuration and moves to the target PCell (106) and PSCell (108). Thus, UE (102) does not lose PSCell (SCG) during handover and throughput does not drop. Therefore, user experience is not affected.

[0168] FIG. 13 depicts the flow diagram (1300) of a method for handling the conditional handover with the PCell and the PSCell, according to embodiments as disclosed herein. The method utilizes an optimization module to make a decision of performing execution between, at least a CHO (MCG) + CPAC (SCG) configuration, or at least a CHO (MCG) only configuration, based on a UE-serving cell signal condition.

[0169] At 1302, the method includes configuring, by a serving cell network node (104), a plurality of CHO (MCG) + CPAC (SCG) configurations for the UE (102) for handover to a plurality of candidate target cells, where the UE (102) is connected to the UE-serving cell. When the network (1002) configures the plurality of CHO (MCG) + CPAC (SCG) configurations on the plurality of candidate target cells, the UE (102) performs measurements and evaluates in parallel, the condition for both Pcell and PScell belonging to the plurality of candidate target cells.

[0170] At step 1304, the method includes detecting, by the UE (102), that the UE-serving cell condition is poor and UE-serving cell connection is deteriorating. In an example embodiment, the UE-serving cell signal condition can be detected by the UE using at least one of a pre-determined factors such as without limitation, an Reference signal received power (RSRP) levels of the UE-serving cell below a certain threshold, a change in the RSRP level with respect to time, a change in RSRP level with respect to a per distance movement of the UE (102) in a geographic location, a Block Error Rate (BLER) value for a PCell, Change in the BLER rate with respect to time, Change in the BLER rate with respect to the a per distance movement of the UE in a geographic location, Signal to Interference Noise Ratio (SINR) Value, and a PDCCH / PDSCH decoding failure rate. In an embodiment herein, the UE (102) may use Artificial Intelligence and Machine Learning based technique to predict that the UE (102) may face service loss / RLF / SCG Failure. Further, in an embodiment herein, the UE (102) may also maintain a database (1030) of RLFs / SCG Failure along with location and cell details. The UE (1030) can use this database to predict any probable RLF / SCG failure.

[0171] At step 1306, the method includes detecting by the UE (102), at least one of: the CHO condition from the CHO+CPAC configuration is satisfied, and the CHO+CPAC condition is satisfied. In an embodiment herein, an evaluation criteria for PCell (MCG) (106) handover is satisfied but conditional PSCell (10104A) addition (SCG) is not satisfied.

[0172] At step 1308, the method includes applying the CHO+CPAC configuration to move to the candidate target cell, when CHO+CPAC condition is satisfied. The UE (102) thus can retain the service continuity and seamless data connectivity during the CHO attempt with losing connection with serving PCell (1010) and serving PSCell (1014). In an embodiment herein, the UE (102) keeps monitoring the serving PSCell (1014). The UE (1030) monitors the serving cell measurement while waiting for conditional PSCell (108) addition (SCG) to be satisfied. Further, the UE (102) detects loss of the UE-serving cell connection using the afore-stated pre-determined factors to retain the service continuity and seamless data connectivity during a CHO attempt.

[0173] At step 1310, the method includes monitoring by the UE (102), the UE-serving cell connection is deteriorating, when at least one of the conditions are satisfied such as the CHO condition; and the CHO+CPAC condition. At step 1312, the method includes checking by the UE (102), an event for Attemptcondreconfig bit set, while the only the CHO condition for target PCell (106) is satisfied.

[0174] At step 1314, the method includes declaring internally by the UE (102) loss of UE-service cell connection, and moving to the candidate target PCell, upon checking by the UE (102), the handover event for Attemptcondreconfig bit is set. In an embodiment herein, the UE declares SCG failure and applies CHO configuration to move to target PCell while not waiting for PSCell to be satisfied. At step 1316, the UE (102) can send a SCG failure report to the serving PCell (1010). In an embodiment herein, when the UE (102) checks that, the handover event for Attemptcondreconfig bit is not set and UE serving cell condition is deteriorating. The UE can apply CHO condition to move to the target PCell (108) and upon moving to the target PCell (108), the UE sends SCG Failure information to target PCell (106) to inform about SCG addition failure.

[0175] Therefore, according to the embodiments herein, when the network node configures CHO (MCG ) + CPAC (SCG) configuration on the plurality of candidate target cells and attemptCondReconfig bit can be set as True in ConditionalReconfiguration IE, the UE (102) monitors serving cell measurement, while waiting for conditional PSCell addition (SCG) to be satisfied. When the UE (102) determines probable loss of the UE-serving cell connection and the condition for Conditional PSCell is not satisfied, the UE (102) declares service loss on current serving cell and handovers to target PCell (1010) using configuration present in the ConditionalReconfiguration IE as the attemptCondReconfig bit is set in the CHO configuration. This proposed method enables the UE (102) to take proactive action to move to target cell before it experiences radio link failure and goes into no service in the serving cell for waiting for PScell evaluation criteria to be satisfied and thus enhances service continuity.

[0176] FIG. 14 depicts the flow diagram (1400) of the method for handling the conditional handover of the UE (102) to the at least one target cell, by optimizing the CHO for the cell A (e.g., Pcell) and the CPAC for the cell B (PScell), according to embodiments as disclosed herein. The cell A and the cell B are associated with the candidate target network node (104A).

[0177] At step 1402, the method includes configuring by the network node (104) for the UE (102), CHO+CPAC configurations (condReconfigId-r16:1) for cell A+cell B, and only the CHO configuration (condReconfigId-r16:2) for the cell A. The UE (102), is connected to PCell and PSCell of the UE-serving network node (104). In an embodiment herein, when the network configures CHO and Conditional PSCell configuration for Cell A and Cell B (condReconfigId-r16:1) and another independent CHO configuration for Cell A (condReconfigId-r16:2), the UE (102) evaluates conditions for both the cell A and the cell B simultaneously and also the UE (102) monitors, the UE-serving cell condition in parallel.

[0178] At step 1404, the method includes checking by the UE (102), if condition for only CHO configuration (condReconfigId-r16:2) for the Cell A is satisfied. In an embodiment herein, when condition criteria for cell A gets satisfied, condReconfigId-r16:2 is fully satisfied as it is CHO only configuration and CHO condition on condReconfigId-r16:1 is satisfied where, conditional PSCell event criteria (CPAC configuration) yet to be fulfilled.

[0179] At step 1406, the method includes keep evaluating by the UE (102), the CHO + CPAC configuration for the cell A and the cell B, and the only CHO configuration for the cell A, when the condition for CHO configuration (condReconfigId-r16:2) for the Cell A is not satisfied, and

[0180] At step 1408, the method includes detecting by the UE (102), the condition condReconfigId-r16:1 associated condition for the CPAC configuration (cell B) is not satisfied, when the condition for only CHO configuration (condReconfigId-r16:2) and CHO configuration in condReconfigId-r16:1, for the Cell A is satisfied.

[0181] At step 1410, the method includes, checking by the UE (102), if at least one of: the UE-serving cell connection is deteriorating and the condition for the CPAC configuration for the cell B is satisfied. In an example embodiment herein, the UE checks for the UE-serving cell connection is deteriorating, using the plurality of pre-determined factors such as without limitation, the RSRP levels of the UE-serving cell below a certain threshold, a change in the RSRP level with respect to time, a change in RSRP level with respect to a per distance movement of the UE in a geographic location, a Block Error Rate (BLER) value for a PCell, Change in the BLER rate with respect to time, Change in the BLER rate with respect to the a per distance movement of the UE in a geographic location, Signal to Interference Noise Ratio (SINR) Value, and PDCCH / PDSCH decoding failure rate, and so on. In an embodiment herein, the UE (102) may use Artificial Intelligence and Machine Learning based technique to predict that the UE (102) may face service loss / RLF / SCG Failure. Further, in an embodiment herein, the UE (102) can also maintain a database of RLFs / SCG Failure along with location and cell details. The UE (102) can use this database to predict any probable RLF / SCG failure. The UE (102) thus can retain the service continuity and seamless data connectivity during a CHO attempt.

[0182] At step 1412, the UE (102) stays in the UE-serving cell and waits for the condition for the CPAC configuration for the cell B is satisfying, when the UE (102) checks that, the UE-serving cell connection is not deteriorating and the condition for the CPAC configuration for the cell B is not satisfied, and

[0183] At step 1414, the method includes applying by the UE (102), the condReconfigId-r16:2 condition and moving to the target PCell (e.g., cellA), when the UE (102) checks that, the UE-serving cell connection is deteriorating and the condition for the CPAC configuration for the cell B is not satisfied.

[0184] In an embodiment herein, the UE (102) can apply CHO reconfiguration corresponding to cell A, and move to the cell A without further waiting for CPAC condition to satisfy, when serving call connection is deteriorating. Therefore, the UE (102) checks the serving cell condition and until serving cell is not deteriorated, the UE does not trigger handover to target PCell through the condReconfigId-r16:2 but wait for the Conditional PSCell event criteria to be fulfilled for the condReconfigId-r16:1. The UE (102) remains with current serving cell till the PSCell condition is satisfied or the serving cell conditions become poor. Once the PSCell condition is satisfied, the UE (102) applies CHO (MCG)+CPAC(SCG) configuration and moves to target PCell and PSCell. This proposed method makes the UE (102) maintain the data throughput and seamless data connectivity and thus user experience is not affected.

[0185] FIG. 15 is the flow diagram (1500) for a method of handling a conditional handover of the UE (102) to a target PCell (106), wherein the UE (102) satisfies only CHO configuration condition of a CHO+CPAC configuration condition for the conditional handover, provided by a UE-serving cell, according to embodiments as disclosed herein.

[0186] At step 1502, the method includes, configuring by a serving network node (104) CHO + CPAC reconfiguration for the UE (102).

[0187] At step 1504, the method includes, detecting by the UE(102), a UE-serving-cell connection is deteriorating and possibility of losing UE service cell connection based on a plurality of network parameters as stated earlier in this document.

[0188] At step 1506, the method includes, evaluating by the UE (102) if CHO condition is satisfied.

[0189] At step 1508, the method includes, evaluating by the UE (102) CPAC condition is satisfied once the CHO condition is satisfied. At step 1510, the method includes applying CHO+CPAC configuration and move to a target network node (104A), when CHO and CPAC configuration are satisfied, and

[0190] At step 1512, the method includes monitoring signal condition on the UE-serving cell, and move to a target PCell with only the CHO configuration, if the UE (102) determines the UE (102) is about to lose UE-serving cell connection and CPAC connection is not satisfied. Further, the UE (102) can predict the possibility for un-achievement of condition for the CPAC reconfiguration corresponding to handover to the target cell, based on monitoring a plurality of parameters as stated earlier in this document.

[0191] At step 1514, the method comprises, sending by the UE (102) an SCG failure information to the target PCell (106) after a successful handover.

[0192] FIG. 16 and FIG. 17 are flow charts (1600 and 1700) illustrating the method for handing of Conditional PS cell configuration for service continuity and higher throughput, according to embodiments as disclosed herein.

[0193] As shown in FIG. 16, at 1602, the UE (102) is connected to the PCell and the SCell. The network configures the CHO and CPAC configuration for the UE (102). At 1604, the serving cell condition of the UE (102) is bad and deteriorating. At 1606, either CHO or CPAC or combination of the CHO and CPAC conditions are not satisfied. At 1608, the method includes applying the combination of the CHO and CPAC configuration and the UE (102) moves to the target cell.

[0194] At 1610, the UE (102) monitors the signal conditions on the current cell and if the UE (102) is about to loose connection with the current serving cell. At 1612, the method includes determining the network provided configuration. The UE (102) determines that AttemptCondReconfig bit is set? If the AttemptCondReconfig bit is set then, at 1614, the UE (102) internally declares the service loss on the serving cell and moves to the target cell. If the AttemptCondReconfig bit is not set then, at 1616, the UE (102) applies only the CHO part of the configuration from the network.

[0195] As shown in FIG. 17, at 1702, the UE (102) is connected to the PCell and the PSCell. The network is configured CHO+CPAC (conReconfigId:r-16:1) configuration for CellA and ell B and CHO alone configuration (conReconfigId:r-16:2) for Cell A. At 1704, UE (102) determines that the CHO (cell A) condition is satisfied. If the CHO (cell A) condition is not satisfied, then at 1706, the UE (102) keeps evaluating the CHO and CPAC associated conditions.

[0196] If the CHO (cell A) condition is satisfied then, at 1708, the UE determines that the conReconfigId:r-16:2 associated condition is satisfied (Pcell:Cell A), but the CPAC part (PSCell:Cell B) of conReconfigId:r-16:1 is not satisfied and only CHO part is satisfied. At 1710, the UE (102) monitors signal conditions on the current cell. At 1712, the UE (102) determines that the current cell condition is bad or CPAC part of conReconfigId:r-16:1 satisfied?

[0197] If the current cell condition is not bad or the CPAC part of conReconfigId:r-16:1 is not satisfied then, at 1714, the UE (102) applies the CHO condition (e.g., conReconfigId:r-16:2 ) only and moved to the target Cell. If the current cell condition is bad or the CPAC part of conReconfigId:r-16:1 is not satisfied then, at 1716, the UE (102) stays on the current PCell and PSCell, until target PSCell condition is satisfied or current Pcell condition becomes poor.

[0198] FIG. 18 shows various hardware components of the UE (102), according to embodiments as disclosed herein. The UE (102) can be, for example, but not limited to a laptop, a desktop computer, a notebook, a Device-to-Device (D2D) device, a vehicle to everything (V2X) device, a smartphone, a foldable phone, a smart TV, a tablet, an immersive device, and an internet of things (IoT) device.

[0199] In an embodiment, the UE (102) includes a processor (1810), a communicator (1820), a memory (1830), and an MCG and SCG handling controller (1840). The processor (1810) is coupled with the communicator (1820), the memory (1830), and the MCG and SCG handling controller (1840).

[0200] Consider, the UE (102) handles the CHO when the UE is configured in the MCG and the SCG in the wireless network (100). The target cell is at least one of: the target PCell and target PSCell.

[0201] In an embodiment, the MCG and SCG handling controller (1840) receives the RRC reconfiguration comprising a CHO and the CPAC from the network entity (e.g., source eNB). Further, the MCG and SCG handling controller (1840) sends the RRC Reconfiguration complete to the network entity. Further, the MCG and SCG handling controller (1840) performs a measurement for a condition associated for the CHO and CPAC. The MCG and SCG handling controller (1840) evaluates whether at least one CHO condition for the MCG is satisfied and the CPAC condition for the SCG is not satisfied.

[0202] In another embodiment, the MCG and SCG handling controller (1840) receives the RRC reconfiguration comprising the CHO and Conditional PSCell Addition and Change from a network entity. The RRC Reconfiguration comprises an attempt configuration bit that is set. Further, the MCG and SCG handling controller (1840) sends the RRC reconfiguration complete to the network entity. Further, the MCG and SCG handling controller (1840) performs the measurement for the condition associated for the CHO and CPAC. The MCG and SCG handling controller (1840) evaluates whether at least one CHO condition for the MCG is satisfied and the CPAC condition for the SCG is not satisfied.

[0203] Further, the MCG and SCG handling controller (1840) detects whether the serving cell from the MCG is becoming poor based on the evaluation. In an embodiment, the MCG and SCG handling controller (1840) detects that the MCG cell is becoming poor based on at least one parameter, wherein the at least one parameter comprises at least one of: a Reference Signal Received Power (RSRP) level of a serving cell below a certain threshold, a change in the RSRP level with respect to a time, a change in the RSRP level with respect to a movement of the UE, a Block Error Rate (BLER) value for a Pcell, a change in the BLER rate with respect to a time, a change in the BLER rate with respect to a movement of the UE, a Signal to Interference Noise Ratio (SINR) value, a Physical Downlink Control Channel (PDCCH) decoding failure rate, and a Physical Downlink Shared Channel (PDSCH) decoding failure rate.

[0204] In another embodiment, the MCG and SCG handling controller (1840) detects that the MCG cell is becoming poor based on at least one of: a data driven module, a Radio Link Failure　(RLF) failure stored in a memory and a Secondary Cell Group (SCG) failure stored in the memory.

[0205] In an embodiment, the MCG and SCG handling controller (1840) performs the conditional handover of the serving cell from the MCG to the target cell upon detecting that the serving cell is becoming poor and not waiting for CPAC condition to satisfy for SCG candidate cells when the network has provided CHO & CPAC configuration for a list of candidate cells. In another embodiment, the MCG and SCG handling controller (1840) applies the CHO target cell configuration and moving to the target cell upon detecting that the serving cell is becoming poor with CPAC condition meet. In another embodiment, the MCG and SCG handling controller (1840) waits for at least one conditional event with an MCG configuration and a SCG configuration that are satisfied, wherein the UE (102) does not apply a conditional reconfiguration of a standalone CHO event until a serving cell of the UE (102) is in a service condition and serving cell has not deteriorated.

[0206] In an embodiment, the MCG and SCG handling controller (1840) performs the CHO and moves to an MCG target cell without waiting for conditional PS cell evaluation completion during deterioration of the serving cell, when the UE (102) is configured with both an MCG configuration and a SCG configuration in the at least one conditional event along with anattemptCondReconfig flagin a conditional reconfiguration to retain the service continuity.

[0207] In another embodiment, the UE (102) is connected to both MCG and SCG and receives standalone CHO configuration from the network, the MCG and SCG handling controller (1840) handovers to the target cell and a target PSCell once the at least one CHO condition for the MCG is satisfied and the SCG is not satisfied, when the UE (102) waits for the at least one conditional event with the MCG configuration and the SCG configuration that are satisfied, wherein the UE (102) does not apply the conditional reconfiguration of the standalone CHO event until the serving cell of the UE is in the service condition and not deteriorated.

[0208] Further, the MCG and SCG handling controller (1840) retains the service continuity and the data connectivity.

[0209] In an embodiment, the MCG and SCG handling controller (1840) transmits the SCG failure information message without waiting for the conditional PS cell evaluation completion during deterioration of the serving cell when the UE (102) is configured with both MCG configuration (CHO) and SCG configuration (CPAC) in the at least one conditional event in a conditional reconfiguration to retain the service continuity.

[0210] In an embodiment, the MCG and SCG handling controller (1840) transmits the SCG failure information message to the target cell, after moving to the target cell, to inform about an SCG addition failure. In an embodiment, the MCG and SCG handling controller (1840) transmits the SCG failure information message to the target cell after the UE (102) sending a RRC reconfiguration complete message to the target cell after applying CHO configuration without applying CPAC configuration.

[0211] The MCG and SCG handling controller (1840) is physically implemented by analog or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits, or the like, and may optionally be driven by firmware.

[0212] Further, the processor (1810) is configured to execute instructions stored in the memory (1830) and to perform various processes. The communicator(1820) is configured for communicating internally between internal hardware components and with external devices via one or more networks. The memory (1830) also stores instructions to be executed by the processor (1810). The memory (1830) may include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard discs, optical discs, floppy discs, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In addition, the memory (1830) may, in some examples, be considered a non-transitory storage medium. The term "non-transitory" may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term "non-transitory" should not be interpreted that the memory (1830) is non-movable. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in Random Access Memory (RAM) or cache).

[0213] Further, at least one of the pluralities of modules / controller may be implemented through the AI model using a data driven controller (not shown). The data driven controller can be a ML model based controller and AI model based controller. A function associated with the AI model may be performed through the non-volatile memory, the volatile memory, and the processor (110). The processor (110) may include one or a plurality of processors. At this time, one or a plurality of processors may be a general purpose processor, such as a central processing unit (CPU), an application processor (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and / or an AI-dedicated processor such as a neural processing unit (NPU).

[0214] The one or a plurality of processors control the processing of the input data in accordance with a predefined operating rule or AI model stored in the non-volatile memory and the volatile memory. The predefined operating rule or artificial intelligence model is provided through training or learning.

[0215] Here, being provided through learning means that a predefined operating rule or AI model of a desired characteristic is made by applying a learning algorithm to a plurality of learning data. The learning may be performed in a device itself in which AI according to an embodiment is performed, and / o may be implemented through a separate server / system.

[0216] The AI model may comprise of a plurality of neural network layers. Each layer has a plurality of weight values, and performs a layer operation through calculation of a previous layer and an operation of a plurality of weights. Examples of neural networks include, but are not limited to, convolutional neural network (CNN), deep neural network (DNN), recurrent neural network (RNN), restricted Boltzmann Machine (RBM), deep belief network (DBN), bidirectional recurrent deep neural network (BRDNN), generative adversarial networks (GAN), and deep Q-networks.

[0217] The learning algorithm is a method for training a predetermined target device (for example, a robot) using a plurality of learning data to cause, allow, or control the target device to make a determination or prediction. Examples of learning algorithms include, but are not limited to, supervised learning, unsupervised learning, semi-supervised learning, or reinforcement learning.

[0218] Although FIG. 18 shows various hardware components of the UE (102) but it is to be understood that other embodiments are not limited thereon. In other embodiments, the electronic device UE (102) may include less or more number of components. Further, the labels or names of the components are used only for illustrative purpose and does not limit the scope of the invention. One or more components can be combined together to perform same or substantially similar function in the UE (102).

[0219] FIG. 19 is a flow chart (1900) illustrating the method of handling the CHO and the CPAC conditions on the candidate cell in the wireless network (100), according to embodiments as disclosed herein. At step 1902, the method includes evaluating whether at least one CHO condition for the MCG is satisfied and the CPAC condition for the SCG is not satisfied. At step 1904, the method includes detecting whether the serving cell is becoming poor based on the evaluation. At step 1906, the method includes performing the conditional handover of the serving cell to the target cell upon detecting that the serving cell is becoming poor and not waiting for CPAC condition to satisfy for SCG candidate cells when the network has provided CHO & CPAC configuration for list of candidate cells. At step 1908, the method includes applying the CHO target cell configuration and moving to the target cell upon detecting that the serving cell is becoming poor with CPAC condition meet. At step 1910, the method includes waiting for at least one conditional event with an MCG configuration and a SCG configuration that are satisfied, wherein the UE (102) does not apply the conditional reconfiguration of a standalone CHO event until a serving cell of the UE (102) is in the service condition and serving cell has not deteriorated. At step 1912, the method includes retaining the service continuity and the data connectivity.

[0220] FIG. 20A is the schematic diagram (2000A) depicting a UE (102) attempting a conditional PCell and a conditional PSCell handover in the network, according to embodiments as disclosed herein. In an embodiment herein, the UE (102) can make decision of performing handover execution with one of, a CHO (MCG) reconfiguration, and a CHO (MCG) and CPAC (SCG) (CHO+CPAC) reconfiguration, based on a UE-serving cell condition. In an embodiment herein, the UE-serving cell condition, can enable the UE (102) to retain service continuity and seamless data connectivity. Embodiments herein, plays a vital role in maintaining service continuity when at T1, the UE is configured by a serving network node (104) with a plurality of CHO(MCG)+CPAC(SCG) reconfigurations of a plurality of candidate target cells for improving data performance and enhancing user experience by accomplishing handover. At T2, the UE (102) can monitor UE-serving cell measurement while waiting for at least one conditional PSCell addition (SCG) to get satisfied. Further, the UE (102) can determine deterioration of the UE-serving cell connection with time. In an embodiment herein, the UE (102) can predict losing of the UE-serving cell connection using factors such as number of Physical downlink control channel (PDCCH) or Physical downlink shared Channel (PDSCH) decoding failures, Reference signal received power (RSRP) levels of the serving network node (104) below a certain threshold, change in RSRP level with respect to time, change in RSRP level with respect to UE movement i.e. per unit distance moved by UE, Block error rate (BLER) value for the PCell (1010), change in BLER rate with respect to time, change in BLER rate with respect to UE movement i.e. per unit distance moved by UE, and Signal to interference noise ratio (SINR) value and so on. At T3, the UE (102) can apply CHO reconfiguration with respect to at least a PCell (106) (target PCell) of a candidate target network node (104A) and can move to the PCell (106), without waiting for PSCell (108) of the target network node (104A) to be satisfied. At T4, upon moving to the target PCell (106), the UE (102) can send an SCG failure information to the target PCell (106) in order to inform about target PSCell (108) addition failure.

[0221] In an embodiment herein, the UE (102) can check the UE-serving cell connection and until the UE-serving cell connection is not deteriorated, the UE (102) does not trigger handover to the target PCell (106) but wait for conditional PSCell event criteria to be fulfilled. In an example embodiment herein, the UE (102) can check the UE-serving cell connection using some factors to predict disconnection with the UE-serving cell, wherein the factors are such as but not limited to, number of Physical downlink control channel (PDCCH) or Physical downlink shared Channel (PDSCH) decoding failures, Reference signal received power (RSRP) levels of the serving network node (104) below a certain threshold, change in RSRP level with respect to time, change in RSRP level with respect to UE movement i.e. per unit distance moved by UE, Block error rate (BLER) value for the PCell (1010), change in BLER rate with respect to time, change in BLER rate with respect to UE movement i.e. per unit distance moved by UE, and Signal to interference noise ratio (SINR) value and so on. The UE (102) can remain with the UE-serving cell till PSCell condition is satisfied or the UE-serving cell connection become poor. Once the PSCell condition is satisfied, the UE (102) can apply the CHO(MCG)+CPAC(SCG) configuration and moves to the target PCell and the target PSCell.

[0222] FIG. 20B depicting a graph (2000B) the UE (102) in configured with the CHO+CPAC configuration in all CHO candidate target cells and serving cell gets deteriorated, according to embodiments as disclosed herein. At T1, the UE (102) is connected to the serving PCell (1010) and the PSCell (1014). At T2, the UE (102) is waiting for the CPAC associated condition to get satisfied. Further, the UE (102) determines that the UE-serving cell condition is getting poorer. At T3, the UE (102) handovers to the target PCell (106) by applying the CHO configuration from the CHO+CPAC configuration. At T4, the UE (102), after handover to the target PCell (106), sends the SGC failure information to the target PCell (106) for PSCell addition failure.

[0223] FIG. 20C is a schematic diagram (2000C) depicting a UE (102) in configured with CHO+CPAC configuration for a conditional handover in CHO candidate cells with attemptcondReconfig Flag and UE-serving cell connection is getting deteriorated, according to embodiments as disclosed herein. The UE (102) can apply CHO (MCG) configuration and moves to a target PCell (106) while target PSCell (108) configuration (CPAC condition) is not satisfied.

[0224] At T1, the UE (102) is connected to serving PCell (1010) and PSCell (1014) of a network (1002). The Network (UE-serving cell) configured CHO + CPAC configuration for a plurality of candidate target cells, with "attempcondreconfig" bit is set, wherein the plurality of candidate target cells include PCells of MCG and PSCells of SCG of a plurality of candidate target network nodes. At T2, the UE (102) is waiting for CHO condition for a target candidate cell to get satisfied. Further, the UE (102) determines that, UE-serving cell condition is getting poorer. At T3, the UE (102) declares service loss on serving PCell (1010) and sends an SGC failure report and the UE (102) handovers to a target PCell (106) by Applying CHO configuration from the CHO+CPAC configuration, while not further waiting for associated CPAC condition to get satisfied, as "attempcondreconfig" bit was set in the CHO+CPAC configuration.

[0225] FIG. 21A depicts the schematic diagram (2100A) of the system for optimizing a conditional handover of the UE configured by a network node (UE-serving cell) with CHO+CPAC configuration and CHO only configuration in CHO candidate cells and serving cell is NOT deteriorated, according to embodiments disclosed herein.

[0226] FIG. 21B depicts the comparison graphical presentation (2100B) of a throughput (shown in Y axis) with time (shown in X axis) for the proposed condition handover method and prior arts. The proposed condition handover has not dropped (as shown S2), whereas the prior art condition handover has dropped (as shown S1).

[0227] The various actions, acts, blocks, steps, or the like in the flow charts may be performed in the order presented, in a different order or simultaneously. Further, in some embodiments, some of the actions, acts, blocks, steps, or the like may be omitted, added, modified, skipped, or the like without departing from the scope of the invention.

[0228] The embodiments disclosed herein can be implemented through at least one software program running on at least one hardware device and performing network management functions to control the network elements. The elements include blocks which can be at least one of a hardware device, or a combination of hardware device and software module.

[0229] The embodiments disclosed herein describe methods and systems for handling conditional PCell and PSCell handover within a network. Therefore, it is understood that the scope of the protection is extended to such a program and in addition to a computer readable means having a message therein, such computer readable storage means contain program code means for implementation of one or more steps of the method, when the program runs on a server or mobile device or any suitable programmable device. The above description is only for the purpose of illustrating the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the scope and principle of the present invention are intended to be included therein.

[0230] Therefore, it is understood that the scope of the protection is extended to such a program and in addition to a computer readable means having a message therein, such computer readable storage means contain program code means for implementation of one or more steps of the method, when the program runs on a server or mobile device or any suitable programmable device. The method is implemented in at least one embodiment through or together with a software program written in e.g., Very high speed integrated circuit Hardware Description Language (VHDL) another programming language, or implemented by one or more VHDL or several software modules being executed on at least one hardware device. The hardware device can be any kind of portable device that can be programmed. The device may also include means which could be e.g., hardware means like e.g., an ASIC, or a combination of hardware and software means, e.g., an ASIC and an FPGA, or at least one microprocessor and at least one memory with software modules located therein. The method embodiments described herein could be implemented partly in hardware and partly in software. Alternatively, the invention may be implemented on different hardware devices, e.g., using a plurality of CPUs.

[0231] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments and examples, those skilled in the art will recognize that the embodiments and examples disclosed herein can be practiced with modification within the scope of the embodiments as described herein.

Claims

1.A method for handling a conditional handover, CHO, by a user equipment, ,UE, in a wireless network (100), comprising:identifying at least one of whether at least one CHO condition for a master cell group, MCG, is satisfied or whether a conditional primary secondary cell, PSCell, addition and change, CPAC, condition for a secondary cell group, SCG, is satisfied;detecting whether a serving cell from the MCG is becoming poor; andin case of detecting that the serving cell is becoming poor, identifying that the at least one CHO condition is satisfied and identifying that the CPAC condition is not satisfied, performing a CHO of the serving cell associated with the MCG to a target cell, without waiting for the CPAC condition to satisfy for a SCG candidate cell.2.The method of claim 1, further comprising:in case of detecting that the serving cell is becoming poor, identifying that the at least one CHO condition is satisfied and identifying that the CPAC condition is satisfied, applying a target cell configuration and moving to the target cell, andin case of detecting that serving cell is not becoming poor, identifying that the at least one CHO condition is satisfied and identifying that the CPAC condition is not satisfied waiting for the CPAC condition is not satisfied to be satisfied while staying in the serving cell.3.The method of claim 1, further comprising:transmitting a SCG failure information message without waiting for a conditional PS cell evaluation completion during deterioration of the serving cell when the UE (102) is configured with both a CHO configuration and an CPAC configuration.4.The method of claim 3, wherein the SCG failure information message is transmitted to the target cell, after moving to the target cell, to inform about an SCG addition failure.5.The method of claim 3, wherein the SCG failure information message is transmitted to the target cell after sending an RRC reconfiguration complete message to the target cell after applying the CHO configuration without applying the CPAC configuration.6.The method of claim 1, further comprising:performing the CHO and moving to an MCG target cell without waiting for conditional PS cell evaluation completion during deterioration of the serving cell, in case that the UE (102) is configured with both an MCG configuration and a SCG configuration along with an attemptCondReconfig flag in a conditional reconfiguration.7.The method of claim 1, wherein the UE (102) is connected to both MCG and SCG and receives a standalone CHO configuration from the wireless network (100),wherein the UE (102) handovers to the target cell and a target PSCell in case that the at least one CHO condition for the MCG is satisfied and the SCG is not satisfied, when the UE (102) waits for at least one conditional event with an MCG configuration and an SCG configuration that are satisfied,wherein the UE (102) does not apply the conditional reconfiguration of the standalone CHO event until the serving cell of the UE is in the service condition and not deteriorated.8.The method of claim 1, wherein identifying at least one of whether at least one CHO condition for the MCG is satisfied or whether the SCG is satisfied comprises:receiving a radio resource control, RRC, reconfiguration comprising a CHO and　CPAC from a network entity;sending, a RRC reconfiguration complete to the network entity; andperforming a measurement for a condition associated for the CHO and CPAC.9.The method of claim 1, wherein identifying at least one of whether the at least one CHO condition for the MCG is satisfied or whether the SCG is satisfied comprises:receiving a RRC reconfiguration comprising a CHO and CPAC from a network entity, wherein the RRC reconfiguration comprises an attempt configuration bit;sending a RRC reconfiguration complete to the network entity; andperforming a measurement for a condition associated for the CHO and CPAC.10.The method of claim 2, wherein applying the target cell configuration and moving to the target cell comprises:declaring a failure on a service cell of the UE;applying a conditional reconfiguration as attemptcondReconfig bit is set; andapplying the target cell configuration and moving to the target cell.11.The method of claim 1, wherein the UE (102) detects that the serving cell is going to no service mode based on at least one parameter, wherein the at least one parameter comprises at least one of: a Reference Signal Received Power, RSRP, level of a serving cell below a certain threshold, a change in the RSRP level with respect to a time, a change in the RSRP level with respect to a movement of the UE, a Block Error Rate, BLER, value for a Pcell, a change in the BLER rate with respect to a time, a change in the BLER rate with respect to a movement of the UE, a Signal to Interference Noise Ratio, SINR, value, a Physical Downlink Control Channel, PDCCH, decoding failure rate, or a Physical Downlink Shared Channel, PDSCH, decoding failure rate.12.The method of claim 1, wherein the UE (102) detects that the serving cell is going to no service mode based on at least one of: a data driven module, a Radio Link Failure,　RLF,　failure stored in a memory or an SCG failure stored in the memory.13.The method of claim 1, wherein the UE (102) handles the CHO when the UE is configured in the MCG and the SCG in the wireless network (100), wherein the target cell is at least one of: a target PCell and a target PSCell.14.A user equipment, UE, (102) for handling a conditional handover, CHO, in a wireless network (100), comprising:memory (1830) storing instructions; andat least one processor (1810), wherein the instructions, when executed by the at least one processor, cause the UE to perform operations according to a method in one of claims 1 to 13.15.A non-transitory computer readable storage medium storing instructions which, when executed by at least one processor (1810, 1840) of a user equipment, UE, (120), cause the UE perform operations according to a method in one of claims 1 to 13.

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