GB2628805A

GB2628805A - Radio resource control processing in L1-L2 triggered mobility

Info

Publication number: GB2628805A
Application number: GB2305066.9A
Authority: GB
Inventors: Zhang Xin; Juhani Kainulainen Jani-Pekka; Dalsgaard Lars
Original assignee: Nokia Technologies Oy
Current assignee: Nokia Technologies Oy
Priority date: 2023-04-05
Filing date: 2023-04-05
Publication date: 2024-10-09
Also published as: WO2024208583A1; CN120958877A; GB202305066D0

Abstract

A method, comprising: receiving, by a user equipment (UE) from a network element, a configuration comprising an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell; decoding, by the user equipment, the at least one cell; determining, by the UE and based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell; and transmitting, to the network element, an indication identifying the at least one preferred target cell. A further method, comprising: transmitting, to a UE from a network element, a configuration comprising an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell; receiving, at the network element from the UE, an indication identifying at least one preferred target cell based on the configuration; and transmitting, to the UE from the network element before a cell switch, a target selection indication comprising at least one target cell. The methods may be executed in a lower layer triggered mobility (LTM) procedure. Also provided are a UE, network element and computer programs for performing the methods.

Description

TITLE: RADIO RESOURCE CONTROL PROCESSING IN L1-L2 TRIGGERED

MOBILITY

FIELD:

100011 Some example embodiments may generally relate to mobile or wireless telecommunication systems, such as Long Term Evolution (LTE) Or fifth generation (50) new radio (NR) access technology, or 5G beyond, or other communications systems. For example, certain example embodiments may relate to apparatuses, systems, and/or methods for radio resource control (RRC) processing in L 1-L2 triggered mobility (LTM).

BACKGROUND:

100021 Examples of mobile or wireless telecommunication systems may is include the Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), LTE Evolved UTRAN (EUTRAN), LTE-Advanced (LTE-A), MulteFire, LTE-A Pro, fifth generation (50) radio access technology or NR access technology, and/or 50-Advanced. 5G wireless systems refer to the next generation (NG) of radio systems and network architecture. 5G network technology is mostly based on NR technology, but the 50 (or NG) network can also build on EUTRAN radio. It is estimated that NR may provide bitrates on the order of 10-20 Gbit/s or higher, and may support at least enhanced mobile broadband (eMBB) and ultra-reliable low-latency communication (URLLC) as well as massive machine-type communication (mMTC). NR is expected to deliver extreme broadband and ultra-robust, low-latency connectivity and massive networking to support the IoT.

SUMMARY:

100031 Some example embodiments may be directed to a method. The method may include receiving, by a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The method may also include decoding, by the user equipment, the at least one cell. The method may further include determining, by the user equipment and based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell. In addition, the method may include transmitting, to the network element, an indication identifying the at least one preferred target cell.

la 100041 Other example embodiments may be directed to an apparatus. The apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and computer program code may be configured to, with the at least one processor, cause the apparatus at least to receive, from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The apparatus may also be caused to decode the at least one cell. The apparatus may further be caused to determine, based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell. In addition, the apparatus may be caused to transmit, to the network element, an indication identifying the at least one preferred target cell.

100051 Other example embodiments may be directed to an apparatus. The apparatus may include means for receiving, from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The apparatus may also include means for decoding the at least one cell. The apparatus may further include means for determining, based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell. In addition, the apparatus may include means for transmitting, to the network element, an indication identifying the at least one preferred target cell.

100061 In accordance with other example embodiments, a non-transitory computer readable medium may be encoded with instructions that may, when executed in hardware, perform a method. The method may include receiving, by a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The method may also include decoding, by the user equipment, the at least one cell. The method may further include determining, by the user equipment and based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell.

In addition, the method may include transmitting, to the network element, an indication identifying the at least one preferred target cell.

100071 Other example embodiments may be directed to a computer program product that performs a method. The method may include receiving, by a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The method may also include decoding, by the user equipment, the at least one cell. The method may further include determining, by the user equipment and based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell. In addition, the method may include transmitting, to the network element, an indication identifying the at least one preferred target cell.

100081 Other example embodiments may be directed to an apparatus that may include circuitry configured to receive, from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The apparatus may also include circuitry configured to decode the at least one cell. The apparatus may further include circuitry configured to determine, based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell. In addition, the apparatus may include circuitry configured to transmit, to the network element, an indication identifying the at least one preferred target cell.

100091 Certain example embodiments may be directed to a method. The method may include transmitting, to a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at is least one cell. The method may also include receiving, at the network element from the user equipment, an indication identifying at least one preferred target cell based on the configuration. The method may further include transmitting, to the user equipment from the network element before a cell switch, a target selection indication comprising at least one target cell.

[0010] Other example embodiments may be directed to an apparatus. The apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and computer program code may be configured to, with the at least one processor, cause the apparatus at least to transmit, to a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The apparatus may also be caused to receive, from the user equipment, an indication identifying at least one preferred target cell based on the configuration. The apparatus may further be caused to transmit, to the user equipment before a cell switch, a target selection indication comprising at least one target cell.

100111 Other example embodiments may be directed to an apparatus. The apparatus may include means for transmitting, to a user equipment from a network element, a configuration comprising an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The apparatus may also include means for receiving, from the user equipment, an indication identifying at least one preferred target cell based on the configuration. The apparatus may further include means for transmitting, to the user equipment before a cell switch, a target is selection indication comprising at least one target cell.

[0012] In accordance with other example embodiments, a non-transitory computer readable medium may be encoded with instructions that may, when executed in hardware, perform a method. The method may include transmitting, to a user equipment from a network element, a configuration is including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The method may also include receiving, at the network element from the user equipment, an indication identifying at least one preferred target cell based on the configuration. The method may further include transmitting, to the user equipment from the network element before a cell switch, a target selection indication comprising at least one target cell.

[0013] Other example embodiments may be directed to a computer program product that performs a method. The method may include transmitting, to a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The method may also include receiving, at the network element from the user equipment, an indication identifying at least one preferred target cell based on the configuration. The method may further include transmitting, to the user equipment from the network element before a cell switch, a target selection indication comprising at least one target cell.

10014 Other example embodiments may be directed to an apparatus that may include circuitry configured to transmit, to a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The apparatus may also include circuitry configured to receive, from the user equipment, an indication identifying at least one preferred target cell based on the configuration. The apparatus may further include circuitry configured to transmit, to the user equipment before a cell switch, a target selection indication comprising at least one target cell.

BRIEF DESCRIPTION OF THE DRAWINGS:

10015] For proper understanding of example embodiments, reference should be made to the accompanying drawings, wherein: 10016IFIG. 1 illustrates an example signal diagram of an L1-L2 triggered 15 mobility (LTM) procedure.

[0017] FIG. 2 illustrates an example radio access network 2 (RAN2) user equipment (UE) delay component.

100181FIG. 3 illustrates an example signal diagram of medium access control control element (MAC CE) based L 1 measurement activation, 20 according to certain example embodiments.

[0019]FIG. 4 illustrates example of another signal diagram, according to certain example embodiments.

10020 FIG. 5 illustrates an example flow diagram of a method, according to certain example embodiments.

[0021]FIG. 6 illustrates an example flow diagram of another method, according to certain example embodiments.

[0022] FIG. 7 illustrates a set of apparatuses, according to certain example embodiments.

DETAILED DESCRIPTION:

[0023] It will be readily understood that the components of certain example embodiments, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. The following is a detailed description of some example embodiments of systems, methods, apparatuses, and computer program products for radio resource control (RRC) processing in layer 1-layer 2 (L1-L2) triggered mobility (LTM).

[0024] The features, structures, or characteristics of example embodiments described throughout this specification may be combined in any suitable manner in one or more example embodiments. For example, the usage of the phrases "certain embodiments," "an example embodiment," "some embodiments," or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment. Thus, appearances of the phrases "in certain embodiments," "an example embodiment," "in some embodiments," "in other embodiments," or other similar language, throughout this specification do not necessarily refer to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more example embodiments. Further, the terms "base station", "cell", "node", "gNB", "network" or other similar language throughout this specification may be used interchangeably. Additionally, as described herein, a serving distributed unit (DU) and a centralized unit (CU) may refer to a same or different network node/function depending on network architecture options and/or implementation.

[0025] As used herein, "at least one of the following: <a list of two or more elements>" and "at least one of <a list of two or more elements>" and similar wording, where the list of two or more elements are joined by "and" or "or," mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0026] Specifications of the 3" Generation Partnership Project (3GPP) describe layer 1-layer 2 (L1-L2) triggered mobility (LTM). Generally, for LTM, a user equipment (UE) may report L1 beam measurements to a serving DU, and the DU may determine when to trigger a cell change of the UE. Thus, LTM may simplify network and UE mobility procedures as well as reduce potential interruption time/delay that may be caused by the mobility. Furthermore, network data forwarding and scheduling may benefit from LTM. In the LTM, the UE may maintain configuration of multiple cells to quickly apply the application of each configuration.

[0027] The LTM may or may not involve a serving cell change, and it may la utilize either a random access channel (RACH) or be RACH-less. In LTM, the serving DU may trigger the execution of a prepared target cell configuration based on lower layer signaling, which may for example be either medium access control control element (MAC CE) or downlink control information (DCI). Upon triggering the cell change, the serving DU is may inform a centralized unit (CU) such that the CU may stop sending any RRC reconfiguration over the serving cell radio link, and initiate data forwarding to the target cell, if needed.

[0028] LTM may be expected to use L1 measurements. These measurements may have the benefit of faster reaction time to radio link degradation in the serving link as the network may save the delay introduced by L3 filtering and time-to-trigger (TTT) for the handover decision. This may result in reducing the number of radio link failures compared to a baseline handover.

10029 FIG. I illustrates an example signal diagram of an LTM procedure.

As illustrated in FIG. 1, at operations 1 and 2, the UE 100 may send a measurement report containing cell quality measurements of the serving and neighboring cells. The UE 100 may be configured by the serving cell to send the measurement report early when it still has a good connection to the serving cell. Using the reported cell quality measurements, the CU 106 may identify a potential set of candidate target cells as shown in FIG. I. [0030] At operation 3, the CU 106 may perform LTM candidate preparation of cells. At operation 4, the CU 106 may request the preparation of candidate target cell(s) controlled by the target DU 104 by sending a UE context setup request message. At operation 5, the target DU 104 may provide the CU 106 with the configuration of the UE 100 in a UE 5 context setup response message containing a container from the target DU 104 to the CU 106. At operation 6, the CU 106 may transmit a UE context modification request to the source DU 102, requesting modification of the candidate target cell(s). At operation 7, the source DU 102 may transmit a UE context modification response to the CU 106 providing the 10 configuration for the modification.

100311 At operation 8, the CU 106 may generate an RRC reconfiguration that may be sent to the UE. The RRC reconfiguration message may include measurement reporting configuration for L 1/L2 handover, and configuration of the prepared candidate cell(s) that the UE 100 needs to execute when it receives a MAC CE command to change the serving cell (perform LI/L2 handover). At operation 9, the CU 106 may transmit a DL RRC message to the source DU 102, where the DL RRC message may include an RRC configuration(s). At operation 10, the source DU 102 may forward the RRC configuration(s) to the UE 100, and in response, the UE 100 may transmit an RRC reconfiguration complete message at operation 11 confirming receipt of the RRC configuration(s). At operation 12, the source DU 102 may forward the UL RRC message to the CU 106.

10032] At operation 13, DL synchronization may be performed with the candidate cells, and at operation 14, timing advance (TA) acquisition with the candidate cells may be performed. At operation 15, the UE 100 may begin reporting, for example periodically reporting, the L1 beam measurement of serving and one or more candidate target cell(s). At operation 16, the source DU 102 may determine that there is a target candidate cell having a better radio link/beam measurement quantity than the serving cell. For example, the determination may include determining that the layer 1 reference signal received power (L1-RSRP) of a target beam measurement is greater than the L1-RSRP of the serving beam measurement + offset for an amount of time (e.g., L 1 TTT). After this determination, the serving cell may send a MAC CE or another Ll message in operation 17 to trigger the cell change to the target candidate cell. At 5 operations 18 and 19, L1/L2 handover from the serving cell (e.g., source DU 102) to the target cell (e.g., target DU 104) may be executed by the UE 100. Both RACH and RACH-less based cell change may be considered. [0033] At operation 20, the target DU 104 may provide to the CU 106 the RRC reconfiguration complete which indicates to the latter that the UE 100 io is now served from the target DU 104. At operations 21 and 22, the UE context may be released from the source DU 102.

100341FIG. 2 illustrates an example radio access network 2 (RAN2) UE delay component. The delay components illustrated in FIG. 2 may be defined based on the information provided in Table 1 below.

is Table 1 -Definition of delay components Component Meaning Value TRizc Processing dine for Up to [10] ms RRCReconfigvration carrying candidate configurations Tprocessing, 1 / Tproeessing.2 Time for UE processing, before and after cell switch command, respectively. This may include L2/3 reconfiguration, RF retuning, baseband retuning, security update if needed, etc. Up to [20] ms for same FR Up to [40] ins for different FR Tmeas Measurement delay (from target appears to cell switch command) Temd Time for processing L I/L2-command (HARQ and parsing) Up to [5] ms Thearcli Time required to search the target cell Oms (if cell is known) Up to [60] ms (if cell is unknown) To Time for fine tracking and acquiring full timing information SMTC periodicity (typ. [20] ms) Tmargin Time for SSB or CSI-RS post- Up to [2] ms processing TIll interruption uncertainty in acquiring the first available PRACH occasion in the new cell Typ. [15] ms TRAK Time for RAR delay Typ. [4] ins Teti -data Time for UE performs the first D L/UL reception/ transmission on the indicated beam of the target cell, after RAR - [0035] In Table 1 Tprocessinej may implicitly be the time for decoding LTM configuration, and Tproeessing,2 may be the configuration application time, while TRRC may be the time for decoding the general RRC configuration. The configuration application time may refer to the time taken at the UE side to set the radio frequency (RF) hardware being configuration compliant. For example, if the new center carrier frequency and subcarrier spacing (SCS) of the synchronization signal block (SSB) is configured, the corresponding RF parameters may be tuned at the RF front end in an inter-frequency scenario.

[0036] In the context of LTM, what the UE may do after receiving the RRC reconfiguration at operation 10 in FIG. 1 is that the UE may decode the RRC configuration either fully (full configuration), or only new configuration information if there is anything new (e.g., delta configuration). The UE may then decode the LTM configuration which is may contain a, for instance, 8 cells' measurement, and report the configuration and perform at least abstract syntax notation 1 (ASN. 1) decoding and validity/compliance check of the candidate cell configurations. These delays may be captured by TRRC and T processing,l.

1003711n practice, the UE may not necessarily perform the decoding of all candidate cells since eventually only one of these candidate cells will be switched to. Thus, to save unnecessary load and effort, the UE may perform the coding and validity check after the target cell is confirmed, meaning after the MAC-CE serving cell switch from the gNB. However, when the UE is performing RRC processing per target cell after the cell switch indication, a longer interruption time may be experienced.

100381 In view of the drawback described above, the UE of certain example embodiments may indicate which target cell is the preferred target cell upon receiving the RRC configuration (i.e., LTM RRC configuration).

Once the UE receives the LTM RRC configuration, the UE may decode the target cells, perform an evaluation fo the target cells based on existing cell values (i.e., cell measurements), and transmit an indication back to the network (e.g., source DU, target DU, and/or CU, or network). The indication transmitted to the network may describe which is the preferred la target cell of the UE (e.g., PCI of the cell). For instance, the preferred target cell may be the cell where the UE expects shortest processing delay, for example, a minimum T processing time may be achieved. The network may use this information, together with prior and/or subsequent L 1 /L3 measurements, to perform LTM cell switch decision.

is 100391According to certain example embodiments, to shorten the service interruption time, and allowing the UE to be ready before the MAC-CE cell switch, the UE RRC processing may be performed prior to the cell switch command upon indication from the network. The network may transmit a target selection indication to the UE before the actual cell switch.

This may allow the UE to select one of the target cells, and perform, for example, RRC ASN.1 decoding and validity/compliance check before the cell switch command. Some UEs may also perform RRC decoding and / or further RRC processing (e.g., MAC / RLC / PDCP parameter processing) at this stage.

100401In certain example embodiments, the network decision to transmit the target cell selection indication may be based on recently transmitted measurement reports received by the network from the UE. The measurement reports may include L I /L3 measurement results. In some example embodiments, this feature may be conditional to the UE capability to perform RRC processing upon receiving the target cell identifier or another information enabling identification of the target cell (e.g., physical cell ID or PCI indication) from the network.

[00411 FIG. 3 illustrates an example signal diagram of MAC CE based Ll measurement activation, according to certain example embodiments. As illustrated in FIG. 3, the signal diagram involves UE 300, source DU 302, 5 target DU 304, and CU 306. At operations 308 and 310, the UE 300 may send a measurement report containing the cell quality measurements of the serving and neighboring cells. The UE 300 may be configured by the serving cell (e.g., source DU 302) to send the measurement report early when it still has a good connection to the serving cell. Using the reported is cell quality measurements, the CU 306 may identify a potential set of candidate target cells to which the UE 300 may be handed over to which may belong to the same DU or different DUs, as illustrated in FIG. 3.

[0042] At operation 312, the CU 306 may decide about the preparation of new cells. In operation 314, the CU 306 may request the preparation of a is candidate target cell(s) controlled by the target DU 304 by sending a UE context setup request message to the target DU 304. At operation 316, the target DU 304 may provide the configuration of the UE to the CU 306 in a UE context setup response message containing a container from the target DU 304 to the CU 306. In other example embodiments, the same operations 314 and 316 may be performed with other target DUs in order to prepare the target cell(s) having received the UE configurations for the candidate target cell(s), the CU 306 may generate an RRC reconfiguration that is sent to the UE 300 in operation 6. Among other information, the RRC reconfiguration message may include measurement reporting configuration for Ll/L2 triggered mobility (equivalently cell switch), and configuration of the prepared candidate cell(s) which the UE needs to execute when it receives a MAC CE command to change the serving cell (perform cell switch).

[00431 In operations 320 and 322, the configurations may be provided to 30 the UE 300, and a clear and explicit indication from the network that X (1=<X<number of prepared candidate cells) configurations of the best cells (e.g., cells that cause the lowest interruption time for the handover such as, for example, based on RSRP/RSRQ or it could be best cell based on a measurement metric) may be decoded by the UE upon reception of the RRC configurations. UE may consider variety of parameters to rank the best cell. At operation 324, the UE may determine, based on intermediate L3 measurement/L3 measurements/L1-measurement report inter-cell beam management (ICBM) about which is the UE's preferred target cell from the history measurement database. The preferred target cell may preferably be associated with the lowest T processing time, as determined from the availability of the existing measurements. For example, the UE 300 may prefer a first candidate cell for which there is existing measurement data over a second candidate cell for which there is no measurement data available. Otherwise, the UE 300 would have to measure the second candidate cell, causing greater T processing time In certain is example embodiments, at operation 324, when the UE determines the best cell, the database may be maintained at the UE side, and it may be from the latest (i.e., up to date) measurements that the UE has performed up to that point. At operation 326, the UE 300 may confirm the reception of the RRC configuration. At operation 328, the UE 300 may indicate the preferred candidate cell (or alternatively one or more) upon the decision made in operation 324 to the gNB via a MAC-CE or acknowledgment. At operation 330, the source DU 302 may forward the UL RRC message to the CU 306. [0044] As further illustrated in FIG. 3, at operation 332, optional early TA acquisition may be performed. At operation 334, the UE 300 may start to periodically report the L 1 measurements of the serving and candidate target cell(s). At operation 336, upon determining that there is a target candidate cell better than the serving cell (e.g., L1-RSRP of the target beam measurement > LI-RSRP of the serving beam measurement + offset for an amount of time (e.g., TTT)), the serving cell may send a MAC CE or a L 1 message in operation 338 to trigger the cell change to the target candidate cell.

At operations 340 and 342, the handover from the serving cell to the target cell may be executed by the UE 300. Here, both RACH and RACHless based cell change may be considered. If early TA acquisition is performed in operation 332, RACH-less may be executed. In operation 346, the target DU 304 may provide to the CU 306 the RRC reconfiguration complete which indicates to the CU 306 that the UE 300 is now served from the target DU 304. In operations 348 and 350, the UE context may be released from the source DU 302. In certain example embodiments, a path switch may be performed to the new serving DU (not 1 0 shown).

[00461 FIG. 4 illustrates example of another signal diagram, according to certain example embodiments. As illustrated in FIG. 4, the signal diagram may involve the UE 400, gNB source 402, and gNB target 404. At operation 406, the UE 400 may be in RRC CONNECTED mode. At operation 408, the UE 400 may perform L3 measurements, and at operation 410, may transmit an L3 measurement report of the measurements to the gNB source 402. At operation 412, the gNB source 402 may implement LTM candidate preparation of cells based on the L3 measurement report, and at operation 414, transmit RRC reconfiguration including UE RRC decoding configuration for the best X cells to the UE 400. The RRC reconfiguration may include LTM candidate configuration.

[0047] At operation 416, the UE may determine preferred candidate (i.e., target) cells based on for example intermediate L3/L3 measurement from the history measurement database. At 418, the UE 400 may determine that 2 5 the 'Processing,' is not needed after the cell switch, for the selected target cell.

At operation 420, the UE 400 may transmit an RRC reconfiguration complete message, which may include an indication of the UE's preferred target cell(s). Alternatively, at operation 422, the UE 400 may transmit an indication of preferred target cell(s) to the gNB source 402 e.g. via a MAC CE. At operation 424, the UE 400 may start to report the L I beam measurement of the serving and candidate target cell(s). At operation 426, the gNB source 402 may perform a decision that a cell change is needed, an LTM decision, and at operation 428, transmit a cell switch command (e.g. MAC-CE) to the UE 400. At operation 430, the Tprocessing,2 may be determined (i.e., time for UE processing after cell switch command). At 432, the UE 400 may transmit an RA preamble (MSG-1) to the gNB target 404, and at operation 434, the gNB target 404 may transmit a reauthorization-request (RAR) (MSG-2) to the UE 400. At operation 436, the UE may perform the first DL/UL reception/transmission on the indicated beam of the target cell, after RAR.

is 100481As illustrated in FIG. 4, in the RRC reconfiguration, the UE may extract the target cell IDs from the RRC configuration without a need to perform a full target cell extraction. Additionally, the UE 400 may be configured to indicate to the network, which cell is the best. The network may provide criteria to the UE 400 on how to achieve this. For example, is the best cell criteria may be based on a comparison of reference signal received power (RSRP)/reference signal received power quality (RSRQ) values. These criteria may be indicated by the network to the UE over infra-frequency inter-frequency, L1-measurements, or L3-measurements.

100491In certain example embodiments, the UE 400 may determine the preferred target cell, and perform a preferred candidate selection based on network indicated criteria. Under T Processing.1, the UE 400 may decode the target cell that is a preferred target cell. Thus, TProce ssing. I may become deterministic. In some example embodiments, this step may be before, during, or after the preferred target signaling. In a first option, the RRCReconfigurationComplete + preference indication may be selected. However, in a second option, the preference indication may be made over MAC-CE. For Toocessinf).2, the UE may have already performed target cell decoding, and therefore no RRC processing may be needed.

100501 FIG. 5 illustrates an example flow diagram of a method, according 30 to certain example embodiments. In an example embodiment, the method of FIG. 5 may be performed by a network entity, or a group of multiple network elements in a 3GPP system, such as LTE or 5G-NR. For instance, in an example embodiment, the method of FIG. 5 may be performed by a UE similar to one of apparatuses 10 or 20 illustrated in FIG. 7.

[0051] According to certain example embodiments, the method of FIG. 5 5 may include, at 500, receiving, by a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one. The method may also include, at 505, decoding, by the user equipment, the at least one cell. The method may further include, at 510, is determining, by the user equipment and based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell. In addition, the method may include, at 515, transmitting, to the network element, an indication identifying the at least one preferred target cell.

100521 According to certain example embodiments, the at least one preferred target cell may be selected on the basis of a lowest processing time to apply the measurement configuration. According to some example embodiments, the existing cell measurement values may include physical layer or network layer measurements. These measurements may have been performed for the plurality of target cells or at least for the at least one preferred target cell beforehand, e.g. before receiving the configuration (before 500). As a consequence, the delays may be reduced. According to other example embodiments, the method may also include receiving, from the network element, a target selection indication including at least one target cell, and selecting a target cell from the target selection indication. [0053] In certain example embodiments, the method may further include performing decoding and a compliance check of the selected target cell before a cell switch command. In some example embodiments, the method may also include extracting a target cell identifier from the configuration.

In other example embodiments, the method may further include receiving, from the network element, criteria for selecting the at least one cell. In further example embodiments, the criteria may be based on a comparison of a reference signal received power or a reference signal received quality of the at least one cell.

[0054] According to certain example embodiments, the user equipment may extract a cell identifier of the at least one cell from the received configuration, and determine the at least one preferred target cell on the basis of the existing cell measurement values without extracting the measurement configuration for the at least one preferred target cell.

According to other example embodiments, the configuration may indicate a set of candidate cells and the indication indicates a subset of the set of candidate cells for decoding. According to some example embodiments, the method may further include omitting decoding of at least one cell of the set of candidate cells not indicated for decoding.

[0055] FIG. 6 illustrates an example flow diagram of another method, according to certain example embodiments. In an example embodiment, the method of FIG. 6 may be performed by a network entity, or a group of multiple network elements in a 3GPP system, such as LTE or 5G-NR. For instance, in an example embodiment, the method of FIG. 6 may be performed by a gNB similar to one of apparatuses 10 or 20 illustrated in FIG. 7.

[0056] According to certain example embodiments, the method of FIG. 6 may include, at 600, transmitting, to a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The method may also include, at 605, receiving, at the network element from the user equipment, an indication identifying at least one preferred target cell based on the configuration. The method may further include, at 610, transmitting, to the user equipment from the network element before a cell switch, a target selection indication comprising at least one target cell.

100571According to certain example embodiments, the method may also include initiating the cell switch based on the indication received from the user equipment and existing cell measurement values of the at least one cell. According to some example embodiments, the transmission of the target selection indication may be based on received physical layer or network layer measurement reports. According to other example embodiments, the method may further include providing the user equipment with criteria for selecting selectin the at least one cell. According to further example embodiments, the criteria may be based on a comparison of a reference signal received power or a reference signal received quality of the at least one cell. In certain example embodiments, the configuration may indicate a set of candidate cells and the indication may indicate a subset of the set of candidate cells for decoding.

100581 FIG. 7 illustrates a set of apparatuses 10 and 20 according to certain is example embodiments. In certain example embodiments, the apparatus 10 may be an element in a communications network or associated with such a network, such as a UE, mobile equipment (ME), mobile station, mobile device, stationary device, IoT device, or other device.

100591In some example embodiments, apparatus 10 may include one or more processors, one or more computer-readable storage medium (for example, memory, storage, or the like), one or more radio access components (for example, a modem, a transceiver, or the like), and/or a user interface. In some example embodiments, apparatus 10 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-loT, Bluetooth, NFC, MulteFire, and/or any other radio access technologies. It should be noted that one of ordinary skill in the art would understand that apparatus 10 may include components or features not shown in FIG. 7.

100601 As illustrated in the example of FIG. 7, apparatus 10 may include or 30 be coupled to a processor 12 for processing information and executing instructions or operations. Processor 12 may be any type of general or specific purpose processor. In fact, processor 12 may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples. While a single processor 12 is shown in FIG. 7, multiple processors may be utilized according to other example embodiments. For example, it should be understood that, in certain example embodiments, apparatus 10 may include two or more processors that may form a multiprocessor system (e.g., in this case processor 12 may represent a multiprocessor) that may support multiprocessing. According to certain example embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

100611Processor 12 may perform functions associated with the operation is of apparatus 10 including, as some examples, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 10, including processes and examples illustrated in FIGs. 1-5.

[0062]Apparatus 10 may further include or be coupled to a memory 14 (internal or external), which may be coupled to processor 12, for storing information and instructions that may be executed by processor 12. Memory 14 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and/or removable memory. For example, memory 14 can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, hard disk drive (HDD), or any other type of non-transitory machine or computer readable media. The instructions stored in memory 14 may include program instructions or computer program code that, when executed by processor 12, enable the apparatus 10 to perform tasks as described herein.

[0063] In certain example embodiments, apparatus 10 may further include 5 or be coupled to (internal or external) a drive or port that is configured to accept and read an external computer readable storage medium, such as an optical disc, USB drive, flash drive, or any other storage medium. For example, the external computer readable storage medium may store a computer program or software for execution by processor 12 and/or is apparatus 10 to perform any of the methods and examples illustrated in FIGs. 1-5.

10064]In some example embodiments, apparatus 10 may also include or be coupled to one or more antennas 15 for receiving a downlink signal and for transmitting via an UL from apparatus 10. Apparatus 10 may further is include a transceiver 18 configured to transmit and receive information. The transceiver 18 may also include a radio interface (e.g., a modem) coupled to the antenna 15. The radio interface may correspond to a plurality of radio access technologies including one or more of GSM, LTE, LTE-A, 50, NR, WLAN, NB-loT, Bluetooth, BT-LE, NFC, RF1D, UWB, and the like. The radio interface may include other components, such as filters, converters (for example, digital-to-analog converters and the like), symbol demappers, signal shaping components, an Inverse Fast Fourier Transform (IFFT) module, and the like, to process symbols, such as OFDMA symbols, carried by a downlink or an UL.

100651For instance, transceiver 18 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 15 and demodulate information received via the antenna(s) 15 for further processing by other elements of apparatus 10. In other example embodiments, transceiver 18 may be capable of transmitting and receiving signals or data directly. Additionally or alternatively, in some example embodiments, apparatus 10 may include an input and/or output device (I/O device). In certain example embodiments, apparatus 10 may further include a user interface, such as a graphical user interface or touchscreen.

10066]In certain example embodiments, memory 14 stores software modules that provide functionality when executed by processor 12. The 5 modules may include, for example, an operating system that provides operating system functionality for apparatus 10. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 10. The components of apparatus 10 may be implemented in hardware, or as any suitable 10 combination of hardware and software. According to certain example embodiments, apparatus 10 may optionally be configured to communicate with apparatus 20 via a wireless or wired communications link 70 according to any radio access technology, such as NR.

[0067]According to certain example embodiments, processor 12 and 15 memory 14 may be included in or may form a part of processing circuitry or control circuitry. In addition, in some example embodiments, transceiver 18 may be included in or may form a part of transceiving circuitry.

[0068] For instance, in certain example embodiments, apparatus 10 may be controlled by memory 14 and processor 12 to receive, from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. Apparatus 10 may also be controlled by memory 24 and processor 12 to decode the at least one cell. Apparatus 10 may further be controlled by memory 24 and processor 12 to determine, based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell. In addition, apparatus 10 may be controlled by memory 24 and processor 12 to transmit, to the network element, an indication identifying the at least one preferred target cell.

[0069] As illustrated in the example of FIG. 7, apparatus 20 may be a network, core network element, or element in a communications network or associated with such a network, such as a gNB, BS, cell, or NW.

[0070] As illustrated in the example of FIG. 7, apparatus 20 may include a processor 22 for processing information and executing instructions or operations. Processor 22 may be any type of general or specific purpose processor. For example, processor 22 may include one or more of general-purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), and processors based on a multi-core processor architecture, as examples. While a single processor 22 is shown in FIG. 7, multiple processors may be utilized according to other example embodiments. For example, it should be understood that, in certain example embodiments, apparatus 20 may include two or more processors that may form a multiprocessor system (e.g., in this case is processor 22 may represent a multiprocessor) that may support multiprocessing. In certain example embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

100711According to certain example embodiments, processor 22 may perform functions associated with the operation of apparatus 20, which may include, for example, precoding of antenna gain/phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of the apparatus 20, including processes and examples illustrated in FIGs. 1-4 and 6.

10072 Apparatus 20 may further include or be coupled to a memory 24 (internal or external), which may be coupled to processor 22, for storing information and instructions that may be executed by processor 22. Memory 24 may be one or more memories and of any type suitable to the local application environment, and may be implemented using any suitable volatile or nonvolatile data storage technology such as a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, fixed memory, and/or removable memory. For example, memory 24 can be comprised of any combination of random access memory (RAM), read only memory (ROM), static storage such as a magnetic or optical disk, hard disk drive (HDD), or any other type of non-transitory machine or computer readable media. The instructions stored in memory 24 may include program instructions or computer program code that, when executed by processor 22, enable the apparatus 20 to perforin tasks as described herein.

[0073] In certain example embodiments, apparatus 20 may further include or be coupled to (internal or external) a drive or port that is configured to accept and read an external computer readable storage medium, such as an optical disc, USB drive, flash drive, or any other storage medium. For example, the external computer readable storage medium may store a computer program or software for execution by processor 22 and/or is apparatus 20 to perform the methods and examples illustrated in FIGs. 1-5 and 6.

[0074] In certain example embodiments, apparatus 20 may also include or be coupled to one or more antennas 25 for transmitting and receiving signals and/or data to and from apparatus 20. Apparatus 20 may further include or be coupled to a transceiver 28 configured to transmit and receive information. The transceiver 28 may include, for example, a plurality of radio interfaces that may be coupled to the antenna(s) 25. The radio interfaces may correspond to a plurality of radio access technologies including one or more of GSM, N B-loT, LTE, 5G, WLAN, Bluetooth, BT-LE, NFC, radio frequency identifier (RFID), ultrawideband (UWB), MulteFire, and the like. The radio interface may include components, such as filters, converters (for example, digital-to-analog converters and the like), mappers, a Fast Fourier Transform (FFT) module, and the like, to generate symbols for a transmission via one or more downlinks and to receive symbols (for example, via an UL).

[0075] As such, transceiver 28 may be configured to modulate information on to a carrier waveform for transmission by the antenna(s) 25 and demodulate information received via the antenna(s) 25 for further processing by other elements of apparatus 20. In other example embodiments, transceiver 18 may be capable of transmitting and receiving signals or data directly. Additionally or alternatively, in some example embodiments, apparatus 20 may include an input and/or output device (I/O device).

10076]In certain example embodiment, memory 24 may store software modules that provide functionality when executed by processor 22. The modules may include, for example, an operating system that provides operating system functionality for apparatus 20. The memory may also store one or more functional modules, such as an application or program, to provide additional functionality for apparatus 20. The components of apparatus 20 may be implemented in hardware, or as any suitable combination of hardware and software.

100771According to some example embodiments, processor 22 and memory 24 may be included in or may form a part of processing circuitry or control circuitry. In addition, in some example embodiments, transceiver 28 may be included in or may form a part of transceiving circuitry.

10078] As used herein, the term "circuitry" may refer to hardware-only circuitry implementations (e.g., analog and/or digital circuitry), combinations of hardware circuits and software, combinations of analog and/or digital hardware circuits with software/firmware, any portions of hardware processor(s) with software (including digital signal processors) that work together to cause an apparatus (e.g., apparatus 10 and 20) to perform various functions, and/or hardware circuit(s) and/or processor(s), or portions thereof, that use software for operation but where the software may not be present when it is not needed for operation. As a further example, as used herein, the term "circuitry" may also cover an implementation of merely a hardware circuit or processor (or multiple processors), or portion of a hardware circuit or processor, and its accompanying software and/or firmware. The term circuitry may also cover, for example, a baseband integrated circuit in a server, cellular network node or device, or other computing or network device.

[0079] For instance, in certain example embodiments, apparatus 20 may be controlled by memory 24 and processor 22 to transmit, to a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. Apparatus 20 may also be controlled by memory 24 and processor 22 to receive, from the user equipment, an is indication identifying at least one preferred target cell based on the configuration. Apparatus 20 may further be controlled by memory 24 and processor 22 to transmit, to the user equipment before a cell switch, a target selection indication comprising at least one target cell.

100801In some example embodiments, an apparatus (e.g., apparatus 10 is and/or apparatus 20) may include means for performing a method, a process, or any of the variants discussed herein. Examples of the means may include one or more processors, memory, controllers, transmitters, receivers, and/or computer program code for causing the performance of the operations.

[0081] Certain example embodiments may be directed to an apparatus that includes means for performing any of the methods described herein including, for example, means for receiving, from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The apparatus may also include means for decoding the at least one cell. The apparatus may further include means for determining, based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell.

In addition, the apparatus may include means for transmitting, to the network element, an indication identifying the at least one preferred target cell.

100821 Additional example embodiments may be directed to an apparatus that includes means for performing any of the methods described herein including, for example, means for transmitting, to a user equipment from a network element, a configuration including an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell. The apparatus may also include means for receiving, from the user equipment, an indication identifying at least one preferred target cell based on the configuration. The apparatus may further include 11,1 means for transmitting, to the user equipment before a cell switch, a target selection indication comprising at least one target cell.

10083] Certain example embodiments described herein provide several technical improvements, enhancements, and /or advantages. For instance, one benefit of certain example embodiments is that the interruption time is associated with the RRC processing is reduced after the cell switch command, and therefore each time UE performs LTM cell switch or subsequent cell switch, the delay is reduced. On the network side, the network can include the information from UE in the cell switch decision, which saves the network energy by reducing processing. Additionally, in some example embodiments, it may be possible to prevent long interruption time when the UE is performing RRC processing per target cell. Other example embodiments may prepare the UE to perform early TA acquisition to only one target cell.

100841A computer program product may include one or more computer-executable components which, when the program is run, are configured to carry out some example embodiments. The one or more computer-executable components may be at least one software code or portions of it. Modifications and configurations required for implementing functionality of certain example embodiments may be performed as routine(s), which may be implemented as added or updated software routine(s). Software routine(s) may be downloaded into the apparatus.

10085 As an example, software or a computer program code or portions of it may be in a source code form, object code form, or in some intermediate form, and it may be stored in some sort of carrier, distribution medium, or computer readable medium, which may be any entity or device capable of carrying the program. Such carriers may include a record medium, computer memory, read-only memory, photoelectrical and/or electrical carrier signal, telecommunications signal, and software distribution package, for example. Depending on the processing power needed, the computer program may be executed in a single electronic digital computer or it may be distributed amongst a number of computers. The computer readable medium or computer readable storage medium may be a non-transitory medium.

[0086] In other example embodiments, the functionality may be performed by hardware or circuitry included in an apparatus (e.g., apparatus 10 or apparatus 20), for example through the use of an application specific integrated circuit (ASIC), a programmable gate array (PGA), a field programmable gate array (FPGA), or any other combination of hardware and software. In yet another example embodiment, the functionality may be implemented as a signal, a non-tangible means that can be carried by an electromagnetic signal downloaded from the Internet or other network.

[0087] According to certain example embodiments, an apparatus, such as a node, device, or a corresponding component, may be configured as circuitry, a computer or a microprocessor, such as single-chip computer element, or as a chipset, including at least a memory for providing storage capacity used for arithmetic operation and an operation processor for executing the arithmetic operation.

[0088] One having ordinary skill in the art will readily understand that the disclosure as discussed above may be practiced with procedures in a different order, and/or with hardware elements in configurations which are different than those which are disclosed. Therefore, although the disclosure has been described based upon these example embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent, while remaining within the spirit and scope of example embodiments. Although the above embodiments refer to 50 NR and LTE technology, the above embodiments may also apply to any other present or future 3GPP technology, such as LTE-advanced, and/or fourth generation (4G) technology.

[0089]Partial Glossary: [0090] 3GPP 3rd Generation Partnership Project 1009115G 5th Generation 1009215GCN 5G Core Network 1009315GS 5G System [0094]BS Base Station [0095] CU Centralized Unit [0096] DAPS Dual Active Protocol Stack [0097] DCI Downlink Control Information [0098] DL Downlink [0099] DU Distributed Unit [0100] eNB Enhanced Node B 101011E-UTRAN Evolved U IRAN [0102] gNB 5G or Next Generation NodeB [0103]L1 Layer 1 (physical layer) [0104] L3 Layer 3 (network layer) [0105] LTM L1-L2 Triggered Mobility 10106 MAC Medium Access Control 101071NR New Radio [0108]NW Network 101091PDCP Packet Data Convergence Protocol 101101RF Radio Frequency or Radio Front-end [0111] RLC Radio Link Control 101121RRC Radio Resource Control 101131RSRP Refence Signal Received Power 101141 RX/TX Receiver/Transmitter [0115] SDAP Service Data Application Protocol [0116] UE User Equipment [0117] UL Uplink

Claims

WE CLAIM: 1. A method, comprising: receiving, by a user equipment from a network element, a 5 configuration comprising an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell; decoding, by the user equipment, the at least one cell; determining, by the user equipment and based on existing cell 10 measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell; and transmitting, to the network element, an indication identifying the at least one preferred target cell.
2. The method according to claim 1, wherein the at least one preferred target cell is selected on the basis of a lowest processing time to apply the measurement configuration.
3. The method according to claims 1 or 2, wherein the existing cell measurement values comprises physical layer or network layer measurements.
4. The method according to any of claims 1-3, further comprising: receiving, from the network element, a target selection indication comprising at least one target cell; and selecting a target cell from the target selection indication.
5. The method according to claim 4, further comprising: performing decoding and a compliance check of the selected target cell before a cell switch command.
6. The method according to any of claims 1-5, further comprising: extracting a target cell identifier from the configuration.
7. The method according to any of claims 1-6, further comprising: receiving, from the network element, criteria for selecting the at least one cell, wherein the criteria are based on a comparison of a reference signal received power or a reference signal received quality of the at least one cell.
8. The method according to any one of claims 1-7, wherein the user equipment extracts a cell identifier of the at least one cell from the received configuration, and determines the at least one preferred target cell on the basis of the existing cell measurement values without extracting the measurement configuration for the at least one preferred target cell.
9. The method according to any one of claims 1-8, wherein the configuration indicates a set of candidate cells and the indication indicates a subset of the set of candidate cells for decoding, and wherein the method further comprises omitting decoding of at least one cell of the set of candidate cells not indicated for decoding.
10. A method, comprising: transmitting, to a user equipment from a network element, a configuration comprising an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell; receiving, at the network element from the user equipment, an indication identifying at least one preferred target cell based on the configuration; and transmitting, to the user equipment from the network element before a cell switch, a target selection indication comprising at least one target cell.
11. The method according to claim 10, further comprising: initiating the cell switch based on the indication received from the user equipment and existing cell measurement values of the at least one cell.
12. The method according to claims 10 or 11, wherein the transmission of the target selection indication is based on received physical layer or network layer measurement reports.
13. The method according to any of claims 10-12, further comprising: is providing the user equipment with criteria for selecting selectin the at least one cell, wherein the criteria are based on a comparison of a reference signal received power or a reference signal received quality of the at least one cell.
14. The method according to any one of claims 10-13, wherein the configuration indicates a set of candidate cells and the indication indicates a subset of the set of candidate cells for decoding.
15. An apparatus, comprising: at least one processor; and at least one memory comprising computer program code, the at least one memory and the computer program code configured to, with storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive, from a network element, a configuration comprising an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell; decode the at least one cell; determine, based on existing cell measurement values of the at least 5 one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell; and transmit, to the network element, an indication identifying the at least one preferred target cell.
16. The apparatus according to claim 15, wherein the at least one preferred target cell is selected on the basis of a lowest processing time to apply the measurement configuration.is
17. The apparatus according to claims 15 or 16, wherein the existing cell measurement values comprises physical layer or network layer measurements.
18. The apparatus according to any of claims 15-17, wherein the apparatus is further caused to: receive, from the network element, a target selection indication comprising at least one target cell; and select a target cell from the target selection indication.
19. The apparatus according to claim 18, wherein the apparatus is further caused to: perform decoding and a compliance check of the selected target cell before a cell switch command.
20. The apparatus according to any of claims 15-19, wherein the apparatus is further caused to: extract a target cell identifier from the configuration.
21. The apparatus according to any of claims 15-20, wherein the apparatus is further caused to: receive, from the network element, criteria for selecting the at least one cell, wherein the criteria are based on a comparison of a reference signal received power or a reference signal received quality of the at least one cell.
22. The apparatus according to any of claims 15-21, wherein the apparatus extracts a cell identifier of the at least one cell from the received configuration, and determines the at least one preferred target cell on the basis of the existing cell measurement values without extracting the measurement configuration for the at least one preferred target cell.
23. The apparatus according to any of claims 15-22, wherein the configuration indicates a set of candidate cells and the indication indicates a subset of the set of candidate cells for decoding, and wherein the method further comprises omitting decoding of at least one cell of the set of candidate cells not indicated for decoding.
24. An apparatus, comprising: at least one processor; and at least one memory comprising computer program code, the at least one memory and the computer program code configured to, with storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit, to a user equipment from a network element, a configuration comprising an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell; receive, from the user equipment, an indication identifying at least one preferred target cell based on the configuration; and transmit, to the user equipment before a cell switch, a target selection indication comprising at least one target cell.
25. The apparatus according to claim 24, wherein the apparatus is further caused to: initiate the cell switch based on the indication received from the user 10 equipment and existing cell measurement values of the at least one cell.
26. The apparatus according to claims 24 or 25, wherein the transmission of the target selection indication is based on received physical layer or network layer measurement reports.
27. The apparatus according to any of claims 24-26, wherein the apparatus is further caused to: provide the user equipment with criteria for selecting selectin the at least one cell, wherein the criteria are based on a comparison of a reference signal received power or a reference signal received quality of the at least one cell.
28. The apparatus according to any of claims 24-27, wherein the configuration indicates a set of candidate cells and the indication indicates a subset of the set of candidate cells for decoding.
29. An apparatus, comprising: means for receiving, from a network element, a configuration comprising an indication identifying at least one cell for decoding and a measurement configuration for measuring the at least one cell; means for decoding the at least one cell; means for determining, based on existing cell measurement values of the at least one cell, the existing cell measurement values measured before or during receiving the configuration, at least one preferred target cell amongst the at least one cell; and means for transmitting, to the network element, an indication identifying the at least one preferred target cell.
30. The apparatus according to claim 29, wherein the at least one preferred target cell is selected on the basis of a lowest processing time to apply the measurement configuration.
31. The apparatus according to claims 29 or 30, wherein the existing cell measurement values comprises physical layer or network layer 15 measurements.
32. The apparatus according to any of claims 29-31, further comprising: means for receiving, from the network element, a target selection indication comprising at least one target cell; and select a target cell from the target selection indication.
33. The apparatus according to claim 32, further comprising: means for performing decoding and a compliance check of the selected target cell before a cell switch command.
34. The apparatus according to any of claims 29-33, further comprising: means for extracting a target cell identifier from the configuration.
35. The apparatus according to any of claims 29-34, further comprising: means for receiving, from the network element, criteria for selecting the at least one cell, wherein the criteria are based on a comparison of a reference signal received power or a reference signal received quality of the at least one cell.
36. The apparatus according to any of claims 29-35, wherein the apparatus extracts a cell identifier of the at least one cell from the received configuration, and determines the at least one preferred target cell on the basis of the existing cell measurement values without extracting the measurement configuration for the at least one preferred target cell.
37. The apparatus according to any of claims 29-36, wherein the configuration indicates a set of candidate cells and the indication indicates a subset of the set of candidate cells for decoding, and wherein the method further comprises omitting decoding of at least one cell of the set of candidate cells not indicated for decoding.
38. An apparatus, comprising: means for transmitting, to a user equipment from a network element, a configuration comprising an indication identifying at least one cell for 20 decoding and a measurement configuration for measuring the at least one cell; means for receiving, from the user equipment, an indication identifying at least one preferred target cell based on the configuration; and means for transmitting, to the user equipment before a cell switch, a target selection indication comprising at least one target cell.
39. The apparatus according to claim 38, further comprising: means for initiating the cell switch based on the indication received from the user equipment and existing cell measurement values of the at least one cell.
40. The apparatus according to claims 38 or 39, wherein the transmission of the target selection indication is based on received physical layer or network layer measurement reports.
41. The apparatus according to any of claims 38-40, further comprising: means for providing the user equipment with criteria for selecting selectin the at least one cell, wherein the criteria are based on a comparison of a reference signal received power or a reference signal received quality of the at least one la cell.
42. The apparatus according to any of claims 38-41, wherein the configuration indicates a set of candidate cells and the indication indicates a subset of the set of candidate cells for decoding.
43. A non-transitory computer readable medium comprising program instructions stored thereon for performing the method according to any of claims 1-14.
44. An apparatus comprising circuitry configured to cause the apparatus to perform a process according to any of claims 1-14.