Early measurements for pscell addition after handover

Abstract

In particular, a method is disclosed, the method comprising obtaining measurement configuration information indicative of a measurement configuration of measurements of at least one target secondary cell of a mobile communication network, performing a handover to the target cell, and starting the measurements of the at least one target secondary cell based at least in part on the measurement configuration information prior to and / or during performing the handover. Further, a method is disclosed, the method comprising receiving target secondary cell information indicative of at least one target secondary cell from a target node, transmitting, upon receiving the target secondary cell information, measurement configuration information based at least in part on the target secondary cell information, the measurement configuration information being indicative of a measurement configuration of measurements of the at least one target secondary cell. Corresponding apparatuses, computer programs and systems are also disclosed.

Description

TECHNICAL FIELD

[0001] The following disclosure relates to the field of handover, e.g. conditional handover, or more specifically to systems, apparatuses and methods for early measurements to perform PSCell addition, e.g. conditional PSCell addition, after handover, e.g. conditional handover. BACKGROUND

[0002] 3GPP Rel-16 specifies a conditional handover (CHO) procedure. Further improvements shall be studied in Rel-17 to enable reliable and low latency handover between nodes supporting Dual Connectivity (DC). Rel-17 MR-DC WI RP-193249 defines one objective related to support of conditional Primary SCG Cell (PSCell) change / addition, in particular to support scenarios not covered in Rel-16 NR mobility WI. In addition, it contains aspects of NR Rel-16 MobeEnh which will be helpful for the above mentioned MR-DC Rel-17 WI, such as CHO related aspects.

[0003] In addition, 3GPP Rel-16 contains some enhancements for efficient Multi-Radio Dual Connectivity (MR-DC) configuration and improving MR-DC performance by e.g. early measurement reporting.

[0004] For MR-DC deployments, when a User Equipment (UE) moves between nodes supporting DC, it is desirable to quickly perform a direct DC handover or addition of a Secondary Cell Group (SCG) after handover. This can require acquiring up-to-date information of all PSCells known to the source via the neighboring cell information.

[0005] In the case of CHO, the handover is triggered in radio conditions where the target PSCell can not be visible during the CHO configuration. Therefore, PSCell measurements can not be configured at the time of CHO configuration. SUMMARY

[0006] One problem of the current CHO approach is that the SN can only be added by the target PCell of the handover after a) it configures the UE with measurements of PSCells and b) the measurements that can take some time to acquire delay the DC configuration. This delay to establish the SN can result in a loss of throughput and reliability of the radio link.

[0007] Therefore, a drawback of CHO is that the target node is not aware of the status of the measurements made by the UE. In some cases, the measurement configuration from the source node can not include measurement objects related to the target secondary cells. In this case, when CHO is triggered, the target node will need to initiate measurements related to its secondary cells together with the CHO measurements at the source node.

[0008] It has been considered that the target node can trigger the measurement reporting via signaling when needed. Furthermore, it has been considered that the source cell can send the UE measurement results to the target cell before CHO, e.g. in the HO request message.

[0009] However, this approach has the following problems:

[0010] a) The measurements forwarded by the source cell can not be relevant for the target PCell, since the source cell can not have information about the PSCell (e.g. frequencies) under control of the target PCell.

[0011] b) Furthermore, these measurement results can easily be outdated, since the time between CHO preparation and CHO execution can be up to several seconds. Adding PSCells after the handover using outdated measurements can lead to handover failures.

[0012] Therefore, in particular, it is an object of the disclosed embodiments to enable fast setup of DC for the target cell in the context of CHO.

[0013] According to a first exemplary aspect, a method is disclosed, the method comprising:

[0014] - obtaining measurement configuration information indicating a measurement configuration for measurements of at least one target secondary cell of a mobile communication network,

[0015] - performing a handover to the target cell, and

[0016] - starting measurements of the at least one target secondary cell based at least in part on the measurement configuration information before and / or during performing the handover.

[0017] The target secondary cell can be part of a target secondary cell group (SCG), and the measurements of the target secondary cell can be measurements of a group of frequencies managed by an SN, including the target secondary cell.

[0018] The handover can be a regular handover or a conditional handover.

[0019] The target secondary cell can in particular be a candidate secondary cell of the target cell (i.e. PCell).

[0020] With the above approach, target secondary cell measurements (e.g. candidate PSCell measurements) can already be started before and / or during the execution of the handover (CHO or regular HO) to the target cell. In particular, some early or earlier measurements of potential target secondary cell frequencies can be started while the device (in particular an Internet of Things (loT) or User Equipment (UE)) is still served by the source node, i.e. before and / or during the execution of the handover (CHO or regular HO) is triggered. In this way, a faster execution of the SN addition / conditional PSCell addition (CPA) can be achieved, in particular to enable a fast DC setup and configuration on the target side.

[0021] In particular, if the source node performs additional measurements of the potential PSCell(s) as well as measurements of the primary cell (PCell) mobility, it can be beneficial for a direct DC handover. Furthermore, early measurements of the potential target PSCell(s) selected by the target at the source can be important for a faster DC activation during mobility. Moreover, when CHO is triggered, the target node can also need measurements related to its secondary cells to be initiated together with the CHO measurements at the source.

[0022] The method can be performed and / or controlled, e.g., by a mobile device (e.g., an automated loT device) and / or a UE. For example, the method can be performed and / or controlled using at least one processor of the mobile device.

[0023] The mobile communication network can be, e.g., a cellular network. The mobile communication network can be, e.g., a mobile phone network like 2G / 3G / 4G / 5G / New Radio (NR) and / or future cellular communication networks. The 2G / 3G / 4G / 5G / NR cellular radio communication standards are developed by 3GPP and are currently available at http: / / www.3gpp.org / .

[0024] According to another exemplary aspect, a computer program is disclosed which, when being executed by a processor, causes a device (e.g., a server) to perform and / or control the actions of the method according to the first exemplary aspect.

[0025] The computer program can be stored on a computer-readable storage medium, in particular on a tangible and / or non-transitory medium. The computer-readable storage medium can be, e.g., a disk or a memory or the like. The computer program can be stored in the computer-readable storage medium in the form of instructions encoding the computer-readable storage medium. The computer-readable storage medium can be used for the operation of the participating devices, like an internal or external memory, e.g., a read-only memory (ROM) or a hard disk of a computer, or for the distribution of the program, like an optical disc.

[0026] According to a further exemplary aspect, there is disclosed an apparatus configured to perform and / or control a method according to the first exemplary aspect or comprising respective means for performing and / or controlling a method according to the first exemplary aspect.

[0027] The means of the apparatus can be implemented in hardware and / or software. They can comprise, for example, at least one processor for executing computer program code for performing the functions, at least one memory storing the program code, or both. Alternatively, they can comprise, for example, circuitry designed to implement the functions, for example, in a chipset or a chip, like an integrated circuit. Typically, the means can comprise, for example, one or more processing means or processors.

[0028] According to a further exemplary aspect, there is disclosed an apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus (e.g., the apparatus described above) at least to perform and / or control a method according to the first exemplary aspect.

[0029] The apparatus disclosed above according to any aspect can be a module or component for a device, for example, a chipset. Alternatively, the apparatus disclosed according to any aspect can be a device, for example, a server or a cloud of servers. The apparatus disclosed according to any aspect can comprise the disclosed components, for example, means, processors, memories, or can further comprise one or more additional components.

[0030] Such an apparatus (e.g., mobile device) as used herein can be, for example, portable (e.g., weigh less than 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1 kg or less), for example, a mobile phone, a personal digital assistant, a computer, a laptop, as non-limiting examples. The apparatus can comprise, for example, or be connectable to a display for displaying information, for example, pictures or videos transferred to the apparatus via a mobile communication network, to name just one non-limiting example. The apparatus can comprise, for example, or be connectable to means for outputting sound, for example, in the form of spoken commands or information.

[0031] According to a second exemplary aspect, there is disclosed a method comprising:

[0032] - receiving, from a target node, target secondary cell information indicating at least one target secondary cell,

[0033] - upon receiving the target secondary cell information, transmitting measurement configuration information based at least partly on the target secondary cell information, the measurement configuration information indicating a measurement configuration for measurements on the at least one target secondary cell.

[0034] The method can in particular comprise receiving target secondary cell information from the target node, the target secondary cell information indicating a target secondary cell group (SCG) comprising the at least one target secondary cell.

[0035] The at least one target secondary cell can in particular be a candidate secondary cell of the target cell.

[0036] The target secondary cell information can in particular indicate measurement related information related to measurements of the at least one target secondary cell.

[0037] For example, the target secondary cell information can indicate a request to include measurement configuration information into a configuration (e.g., a source configuration), the measurement configuration information indicating a measurement configuration for measurements of the at least one target secondary cell.

[0038] The transmission of the measurement configuration information is in particular to a device (e.g., a UE or an loT device) according to the first aspect.

[0039] With the above disclosed method, measurement configuration information for cell measurements (e.g., candidate PSCell measurement(s)) of the target node can already be provided to the source node before and / or during the execution of the CHO to the target node. In this way, early or even earlier measurements started before and / or during the triggering of the HO execution (CHO or regular HO) can be performed using the configuration related to the target node, while the source node still serves the loT device / UE. In this way, a faster execution of the SN addition / CPA can be achieved, in particular to enable a fast DC setup and configuration on the target side.

[0040] The method can for example be performed and / or controlled by a device, e.g., a radio access node, e.g., a master node, e.g., an en-gNB or ng-eNB. Alternatively, the method can be performed and / or controlled by more than one device, e.g., a master node (e.g., an eNB or ng-eNB) and a secondary node. For example, the method can be performed and / or controlled using at least one processor of the radio access node.

[0041] According to another exemplary aspect, a computer program is disclosed which, when executed by a processor, causes a device (e.g., a server) to perform and / or control the actions of the method according to the second exemplary aspect.

[0042] A computer program can be stored on a computer-readable storage medium, in particular on a tangible and / or non-transitory medium. The computer-readable storage medium can be, for example, a disk or a memory such as a ROM, for example. The computer program can be stored in the computer-readable storage medium in the form of instructions encoding the medium. The computer-readable storage medium can be used in the operation of the device, such as an internal or external memory, for example, a read-only memory (ROM) or a hard disk of a computer, or for the distribution of programs, such as a disk.

[0043] According to a further exemplary aspect, there is disclosed an apparatus configured to perform and / or control a method according to the second exemplary aspect or comprising corresponding means for performing and / or controlling a method according to the second exemplary aspect.

[0044] The means of the apparatus can be implemented in hardware and / or software. They can comprise, for example, at least one processor for executing computer program code for performing the required functions, at least one memory which stores the program code, or both. Alternatively, they can comprise, for example, circuitry designed to implement the required functions, for example, in a chipset or a chip, such as an integrated circuit. Generally, the means can comprise, for example, one or more processing means or processors.

[0045] According to a further exemplary aspect, there is disclosed an apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus (e.g., the apparatus described above) at least to perform and / or control a method according to the second exemplary aspect.

[0046] The apparatus disclosed above according to any aspect can be a module or component for a device, for example, a chipset. Alternatively, the disclosed apparatus according to any aspect can be a device, for example, a server or a cloud of servers. The disclosed apparatus according to any aspect can comprise only the disclosed components, for example, means, processors, memories, or can further comprise one or more additional components.

[0047] According to a further exemplary aspect, there is disclosed a system comprising at least one apparatus according to the first exemplary aspect described above and at least one apparatus according to the second exemplary aspect described above.

[0048] With the above-described aspects, a fast or faster setup and configuration of DC can be achieved in the candidate target NR NodeB (gNB). Furthermore, the target node can better decide whether to activate DC based on early measurements. Furthermore, the target node can have a more accurate knowledge of the measurements needed to configure and activate DC.

[0049] In the following, exemplary features and exemplary embodiments of all aspects will be described in further detail.

[0050] According to exemplary embodiments of the first exemplary aspect, the handover is a handover from a source cell to a target cell of a mobile communication network, and the obtaining the measurement configuration information comprises receiving the measurement configuration information from the source node. In this way, for example, the UE / IoT device can have already received the measurement configuration information from the source node for performing early measurements related to the target node before and / or during the HO (CHO or regular HO).

[0051] According to exemplary embodiments of the first exemplary aspect, the method further comprises:

[0052] - obtaining handover configuration information indicating a handover configuration for performing a handover to the target node.

[0053] According to exemplary embodiments of the first exemplary aspect, the obtaining the measurement configuration information and the handover configuration information comprises or includes receiving a radio resource control (RRC) configuration comprising the measurement configuration information and the handover configuration information.

[0054] In this way, with one message, the source node can transmit and the UE / IoT device can receive the measurement configuration information and the handover configuration information, thereby reducing the number of messages to be exchanged.

[0055] According to exemplary embodiments of the first exemplary aspect, the radio resource control configuration further comprises or includes a conditional PSCell addition configuration.

[0056] In particular, the RRC configuration can contain CPA configuration information indicating the CPA configuration.

[0057] In this case, the target node can for example inform the source node to include or comprise a measurement identifier (ID) of the PSCell in the source configuration, wherein the trigger condition is delayed after the HO execution (CHO or regular HO). In particular, according to exemplary embodiments, the PCell HO is first triggered and then, any PSCell addition or CPA can be made, in particular without new signaling (e.g. explicitly) from the new source (i.e. the former target) regarding the CPA configuration. For example, this can be the case for establishing a CPA configuration for one or more SCGs.

[0058] According to exemplary embodiments of the first exemplary aspect, the method further comprises:

[0059] - obtaining the CPA configuration after performing the handover to the target cell.

[0060] In this case, the CPA configuration can in particular be obtained (e.g., received) from the new source node (i.e., from the previous target node). In particular, CPA configuration information indicative of the CPA configuration can be received.

[0061] According to exemplary embodiments of the first exemplary aspect, the measurement configuration information is indicative of one or more measurement identifiers (IDs), each measurement ID being indicative of a measurement configuration for a measurement of a respective potential target secondary cell.

[0062] In this way, the source node can provide one or more measurement IDs, in particular a list of measurement IDs whose measurement results are relevant for the target node, to decide on the SN addition or CPA. In this way, the UE / IoT device can in particular start or perform early measurement(s) of one or more candidate PSCells of the target node. In particular, the target node can inform the source node to include or comprise one or more measurement IDs in the configuration (e.g., source configuration), so that the one or more measurement IDs can be forwarded to the UE / IoT device for such early measurement(s), for example.

[0063] According to exemplary embodiments of the first exemplary aspect, the method further comprises:

[0064] - mapping the measurement results of the measurement identifiers to target measurement identifiers in a target measurement configuration.

[0065] According to exemplary embodiments of the first exemplary aspect, the method further comprises:

[0066] - transmitting, after the execution of the handover, measurement result information indicative of the results of the measurements.

[0067] The transmission of the measurement result information can in particular be a transmission to the target node, which is or represents the new source node after the execution of the handover.

[0068] According to exemplary embodiments of the first exemplary aspect, the method further comprises:

[0069] - transmitting, after the execution of the handover, a handover completion message indicative of the completion of the handover, wherein

[0070] The handover completion message includes or comprises the measurement result information.

[0071] In particular, the UE / IoT device can provide measurement results to the target node as soon as possible after the HO (CHO or regular HO). In this way, the network can be enabled to configure dual connectivity carrier aggregation (DC / CA) as soon as possible after the HO. To this end, the UE / IoT device can in particular provide the measurement results already in the HO completion message.

[0072] According to exemplary embodiments of the first exemplary aspect, the method further comprises:

[0073] - activating dual connectivity based at least in part on the CPA configuration after execution of the handover.

[0074] In particular, the execution of the handover (e.g. PCell HO) can be performed before and / or during the execution of any addition of a secondary target cell (e.g. PSCell addition). In other words, according to exemplary embodiments, the PCell HO can be triggered first and then, any PSCell addition execution or CPA can be made, in particular without new signaling (e.g. explicitly) from the new source regarding the CPA configuration.

[0075] The addition of a secondary target cell (e.g. PSCell addition) can be a conditional addition of a secondary target cell (e.g. conditional PSCell addition).

[0076] According to exemplary embodiments of the first exemplary aspect, the apparatus is or is part of a mobile device and / or an Internet of Things, IoT, device.

[0077] According to exemplary embodiments of the second exemplary aspect, the target secondary cell information and / or the measurement configuration information comprises one or more measurement identifiers indicative of the respective target secondary cell.

[0078] For example, such measurement identifier(s) can be assigned to a specific PSCell and / or to PSCell characteristics, e.g. frequency or frequency band. In this way, the target node can provide the source node with target secondary cell information which can allow for relevant early measurement(s) on the target node before and / or during the handover to the target node.

[0079] In particular, the target secondary cell information and / or the measurement configuration information can include or comprise a list of more than one measurement identifier indicative of the respective target secondary cell. In this way, for example, measurements on several candidate target secondary cells can be started before and / or during the handover.

[0080] For example, the measurement configuration can comprise one or more of the following: measurement ID, measurement object ID, measurement reporting ID.

[0081] According to exemplary embodiments of the second exemplary aspect, receiving target secondary cell information from the target node can be receiving the target secondary cell information without the CPA configuration. In particular, the measurement related configuration(s) can be received from the target node without the CPA configuration. In this case, the CPA configuration can be transmitted to the UE / IoT device by the new source node (i.e. by the former target node) after the PCell HO is triggered.

[0082] In particular, in this case, the source node can inform that the source node includes or comprises the measurement identifier(s) in the source configuration. Then, the PCell HO can be triggered first and then, the new source (e.g. the former target node) can transmit the CPA configuration, which can be applied immediately afterwards. Further, in this case, the UE / IoT device can perform or at least start the measurement(s) based on the measurement identifier(s) before and / or during the CHO execution. The UE / IoT device can then provide the measurement results to the target node as soon as possible, e.g. after the HO (CHO or regular HO). In this way, the network can configure the DC / CA as soon as possible after the HO. For example, the UE / IoT device can provide the measurement results already in the HO completion message.

[0083] The source node can provide the UE / IoT device with a list of one or more measurement IDs whose measurement results are related to the target node to decide on the secondary node addition or CPA.

[0084] According to exemplary embodiments of the second exemplary aspect, the target secondary cell information indicates a request to replicate one or more measurement identifiers in the source configuration, the measurement identifier indicating a measurement configuration for measurements on a respective target secondary cell (e.g. a target SCG comprising the target secondary cell).

[0085] In particular, the request can be a request to replicate one or more measurement identifiers (like {A, B, C}) in the source configuration with new or respectively different measurement identifiers (e.g. {A1, B1, C1}). In this way, the source node can be able to distinguish between measurement identifiers from the target node (e.g. {A1, B1, C1}) and measurement identifiers from the source node.

[0086] Further, the method can comprise adding the new or respectively different measurement identifier(s) to the measurement configuration information to be transmitted. Thus, the measurement configuration information can comprise the new or respectively different measurement identifier(s). The measurement configuration information can in particular be transmitted as part of an RRC configuration (e.g. RRC reconfiguration).

[0087] According to exemplary embodiments of the second exemplary aspect, the method further comprises:

[0088] - mapping the measurement identifier to a source measurement identifier in the source measurement configuration.

[0089] The measurement identifier is in particular a new or different measurement identifier added to the measurement configuration information of the transmission RRC (re)configuration containing the CHO configuration. The target measurement configuration is in particular a target measurement configuration linked to the conditional PSCell addition.

[0090] The measurement ID(s) linked to the conditional PSCell addition can result in triggering a measurement report to the target master radio access node (MN) to prepare the SN as part of the CPA procedure after the handover.

[0091] According to exemplary embodiments of the second exemplary aspect, the method further comprises

[0092] - receiving, after the transmission of the measurement configuration information, handover success information indicating a successful handover to the target node.

[0093] The measurement configuration information can in particular be transmitted to the UE / IoT device before and / or during the handover to the target node, in particular before the handover success information is received, so that the UE / IoT device can start early measurements.

[0094] According to exemplary embodiments of the second exemplary aspect, the receiving of the request information and / or the transmission of the source configuration is performed via a source master node of the mobile communication network.

[0095] The above-mentioned features and example embodiments can equally belong to different aspects.

[0096] It is to be understood that the embodiments and aspects in this section are by way of example only and not limiting.

[0097] Other features will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood that the drawings are designed solely for purposes of illustration to be considered in conjunction with the description. It should be further understood that the drawings are not drawn to scale and that they are merely intended to conceptually illustrate the structures and procedures described herein. BRIEF DESCRIPTION OF DRAWINGS

[0098] In the drawings:

[0099] Figure 1 a schematic block diagram of a system according to exemplary aspects is shown;

[0100] Figures 2a-2b a signaling diagram showing an example embodiment of a method for a conditional handover between a source node and a target node is shown;

[0101] Figure 3A signaling diagram illustrating an example embodiment of a method according to the first example aspect and further illustrating an example embodiment of a method according to the second example aspect is shown;

[0102] Figures 4a-4b A signaling diagram illustrating another example embodiment of a method according to the first example aspect and further illustrating another example embodiment of a method according to the second example aspect is shown;

[0103] Figures 5a-5b A signaling diagram illustrating another example embodiment of a method according to the first example aspect and further illustrating another example embodiment of a method according to the second example aspect is shown;

[0104] Figure 6 A schematic block diagram of an apparatus configured to perform a method according to the first example aspect is shown; and

[0105] Figure 7 A schematic block diagram of an apparatus configured to perform a method according to the second example aspect is shown. DETAILED DESCRIPTION

[0106] The following description is made for the purpose of deepening the understanding of the example embodiments and should be understood as supplementing the description provided in the above summary section of the present specification and read together with it.

[0107] Figure 1 is an example of a schematic high-level block diagram of a system according to the example aspects. The system 100 comprises a mobile device 130, which can be a UE / IoT device.

[0108] The system 100 further comprises a plurality of gNBs 120-1 to 120-7, the signals of which are observable by the mobile device 130. The gNBs 120-1 to 120-7 are part of a mobile communication network.

[0109] First, the mobile device 130 is served by the gNB 120-3 as a primary PCell (thick solid double arrow) and by the gNB 120-1 as a secondary PSCell (thin solid double arrow) via DC. The DC can for example provide increased reliability, lower latency and / or better bandwidth.

[0110] The example of dual connectivity is taken. Embodiments and aspects can also be applied in environments of e.g. multi-connectivity type.

[0111] When the mobile device 130 moves to a neighboring cell (shown by the dashed arrow 2 and the dashed outline 130'), a handover from the PCell of the source primary node gNB 120-3 to the PCell of the target primary node gNB 120-5 can be performed, e.g. a conditional or regular HO.

[0112] Figures 2a-2b is a signaling diagram 200 illustrating an example embodiment of how to perform the standard procedure for a UE 230 to perform a conditional handover between a source gNB 220-3 and a target gNB 220-5. Figure 2a The upper (first) part 200a of the diagram 200 is illustrated, Figure 2b The lower (second) part 200b of the diagram 200 is illustrated. For the sake of clarity, the labels of the respective entities “UE”, “source gNB”, etc. are repeated in Figure 2b .

[0113] For example, the UE 130 can be configured as the UE 230, the source gNB 120-3 can be configured as the gNB 220-3, and / or the target gNB 120-5 can be configured as the gNB 220-5.

[0114] The procedure can include some or all of the following steps:

[0115] Step 201 : The UE transmits a measurement report to the source gNB.

[0116] Step 202: The source gNB decides, based at least in part on the measurement report, whether to initiate a CHO.

[0117] Step 203: The source gNB sends a HO request to the target gNB.

[0118] Step 204: The source gNB can also send a HO request to one or more additional potential target nodes.

[0119] Step 205: The target gNB performs admission control for the requested HO.

[0120] Step 206: The additional potential target gNB(s) can also perform admission control for the requested HO.

[0121] Step 207: To confirm the HO request, the target gNB transmits a HO request acknowledgement to the source gNB.

[0122] Step 208: The additional potential target gNB(s) can also transmit respective HO request acknowledgement(s) to the source gNB.

[0123] Step 209: The source gNB transmits an RRC reconfiguration to the UE, the RRC reconfiguration including a CHO configuration including at least one CHO condition for performing a HO to a target cell of a target node.

[0124] Step 210: The UE evaluates the CHO condition(s) according to the RRC reconfiguration and continues to exchange user data with the source gNB.

[0125] Step 211 : Once the CHO conditions are fulfilled for one of the target cells, the UE stops TX / RX to / from the source node.

[0126] Step 212: The UE transmits a physical layer random access channel (PRACH) preamble to the target gNB.

[0127] Step 213: In response, the target gNB transmits a random access channel (RACH) response to the UE.

[0128] Step 214: The UI transmits RRC reconfiguration complete information to the target gNB, indicating that the RRC reconfiguration is complete.

[0129] Step 215: The target gNB then transmits handover success information to the source gNB.

[0130] Step 216: Upon receiving the handover success information, the source gNB stops TX / RX to / from the UE and can start data forwarding to the target gNB.

[0131] Step 217: The source gNB transmits SN status transfer information to the target gNB.

[0132] Step 218: The source gNB can also perform data forwarding to the target gNB.

[0133] Step 219: The source gNB can further release the other potential target node(s) by transmitting release CHO preparation information.

[0134] Step 220: The communication path is switched.

[0135] Figures 2a-2b A CHO procedure is shown that supports preparation of multiple target cells. In the case of CHO, the HO is conditioned to evaluate the fulfillment of the configured conditions, but the HO command can be received by the UE or most likely by the UE. Thus, the goal of CHO is to improve the HO robustness. For CHO, the UE continues TX / RX with the source cell until the CHO execution conditions are fulfilled for one of the prepared target nodes. Delayed data forwarding (step 218) can be performed, which can be triggered when the source gNB receives the "HO success" message from the target node (step 215).

[0136] The target node can be provided with conditional configuration as part of the HO-REQ-ACK.

[0137] A first possible configuration (configuration 1) can include: master cell group configuration, measurement identifier of the source configuration, e.g. A3. For example, configuration 1 can include only CHO related measurements, e.g. in case it has no CPA configuration.

[0138] A second possible configuration (configuration 2) can comprise configuration 1 plus a secondary cell group configuration. For example, configuration 2 can in particular comprise the measurement identifiers of the target configuration of A4 (CPA after CHO).

[0139] The measurement identifiers of the source node can also be maintained after CHO. In this way, the pending measurement status is allowed to continue in the target node when the target measurement starts.

[0140] Figure 3 is a signaling diagram 300 illustrating how an exemplary procedure for a UE 330 for a conditional handover between a source gNB 320-3 and a target gNB 320-5 can be performed.

[0141] For example, the UE 130 can be configured as the UE 330, the source gNB 120-3 can be configured as the gNB 320-3, and / or the target gNB 120-5 can be configured as the gNB 320-5.

[0142] Figure 3 Further, an example embodiment of a method according to the first exemplary aspect is illustrated and also an example embodiment of a method according to the second exemplary aspect is illustrated. Moreover, the UE 330 can be an example embodiment of an apparatus according to the first exemplary aspect. Furthermore, the source gNB 320-3 can be an example embodiment of an apparatus according to the second exemplary aspect.

[0143] For example, Figure 3 The procedure in can be performed after a HO request (as in step 203) from a source node (e.g., source node 320-3) to a target node (e.g., target node 320-5).

[0144] The procedure can comprise some or all of the following steps:

[0145] Step 331 : The target node prepares a target RRC configuration. In particular, the target node adds thereto measurement configuration information indicating a measurement configuration of a measurement of at least one target secondary cell (e.g., of a target secondary cell group comprising at least one target secondary cell). According to option 1, the measurement configuration information can in particular comprise at least one of a new measurement object identifier (A), a new reporting configuration identifier (B), and a new measurement identifier (C), which can be linked to the CPA.

[0146] Step 332: The target node transmits a HO request acknowledgement, e.g., HO-REQ-ACK, to the source node, thereby acknowledging the previous HO request of the source node. Here, the HO-REQ-ACK also comprises a request to duplicate the new measurement (e.g., {A, B, C}) in the source configuration with different IDs (e.g., {A1, B1, C1}).

[0147] Step 333: When the source node transmits an RRC reconfiguration including the CHO configuration to the UE 330 (as in step 209), the source node adds information for adding new measurements (e.g., by adding measurement identifiers {A1, B1, C1}). The RRC reconfiguration may or may not include the CPA configuration.

[0148] Step 334: Upon receiving an RRC reconfiguration, the UE processes the source measurement configuration, particularly based at least in part on the modified measurement configuration, and creates at least one of the following: a new measurement object (e.g., A1), a new reporting configuration (e.g., B1), and a new measurement identifier (e.g., C1).

[0149] Step 335: Using the measurement configuration from step 334, UE 330 can then begin early measurements of (multiple) target PSCells.

[0150] Step 336: After step 335, execute the CHO if the CHO condition is met. If possible, UE 330 can continue measurement using the source configuration of the selected measurement ID.

[0151] Step 337: UE 330 transfers the new measurement result (C1) to the original measurement (C) and then deletes the new measurement (A1, B1, C1).

[0152] exist Figure 3 In the example shown, target node 320-5 creates at least one new measurement identifier for the source configuration, such as a new measurement object—ID A, a new reporting configuration—ID B, or a new measurement ID—ID C. In this example, target node 320-5 creates a new measurement ID for configuration 2 of the target UE context. Target node 320-5 notifies source node 320-3 to include this measurement ID in the source configuration, where the triggering condition is deferred after the handover is performed.

[0153] Therefore, in Figure 3 In the example, the target and source nodes negotiate a mapping from measurement IDs {A, B, C} at the target to IDs {A1, B1, C1} at the source. This can be called measurement borrowing based on the measurement ID mapping. If no CPA is attached to this in the target configuration, the target node can, for example, propose a new measurement to the source (represented as {A, B, C} in the given example) without creating a new measurement within the target configuration. This can happen, for example, if it is expected that an early measurement will be performed on the target node and if a CPA based on the measurement result later is sufficient.

[0154] A measurement identifier (e.g., {A, B, C}) is linked to the CPA. In this way, measurements related to the target can be started before and / or during the CHO.

[0155] With the above example, the measurements of the measurement ID at the source can also continue seamlessly during and / or after the CHO. And, if the triggering condition is fulfilled after the CHO, the CPA configuration can be performed.

[0156] It can be advantageous if the UE provides measurement results to the target node as soon as possible after the HO (e.g., CHO or regular HO) in order to allow the network (NW) to configure the DC / CA / multi-connectivity as soon as possible after the HO. For example, the UE can provide the measurement results already in the HO completion message or in a reconfiguration completion message (denoted here as Msg3, for example). Reporting early measurements in Msg3 is beneficial for scenarios where the target node can decide to continue or not to continue the CPA based on the temporary measurement results reported in Msg3, for example. Msg3 is just one example.

[0157] Figure 3 The illustrated example includes an exemplary embodiment of a method according to the first exemplary aspect. Further, the UE 330 can be or can be part of an apparatus according to the first aspect.

[0158] The UE 330 (which can be a mobile device, such as a cellular phone) comprises at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the UE at least to perform the following operations:

[0159] - in step 333, obtaining a RRC reconfiguration from the source node 320-3, the RRC reconfiguration comprising at least one of the following, for example:

[0160] i) measurement configuration information indicating a measurement configuration for measurements of at least one target secondary cell (e.g., measurements of a target secondary cell group (SCG) comprising the at least one target secondary cell),

[0161] a measurement configuration, e.g., modifying the measurement configuration {A1, B1, C1}; and

[0162] ii) handover configuration information, e.g., a CHO configuration, indicating a handover configuration for performing a handover to a target cell of the target node 320-5,

[0163] - in step 336, performing a handover from a source cell of the source node 320-3 to a target cell of the target node 320-5 based at least in part on the handover configuration information, and

[0164] - before and / or during performing the handover, in step 335, starting measurements on at least one target secondary cell (e.g., on a target secondary cell group comprising the at least one target secondary cell) based at least in part on the measurement configuration information, e.g., by creating a new measurement object / measurement report / measurement identifier in step 334 and mapping it to the given target PSCell frequency.

[0165] Figure 3 The illustrated example also includes an example embodiment of a method according to the second example aspect. In particular, in this example, the source node 320-3 can be or can be part of an apparatus according to the second aspect.

[0166] The target node comprises at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the target node at least to perform the following operations:

[0167] - in step 332, receiving target secondary cell information from the target node 320-5 indicating at least one target secondary cell (e.g., a target secondary cell group comprising the at least one target secondary cell), e.g., a HO-REQ-ACK,

[0168] - upon receiving the target secondary cell information (e.g., the HO-REQ-ACK), in step 333, transmitting an RRC configuration (e.g., an RRC reconfiguration) to the UE 330, the RRC configuration comprising, e.g., at least one of:

[0169] i) measurement configuration information indicating a measurement configuration for measurements on the at least one target secondary cell (e.g., the target secondary cell or cell group assigned to {A1, B1, C1}) based at least in part on the target secondary cell information, e.g.,

[0170] the HO-REQ-ACK modifies the measurement configuration for measurements on the at least one target secondary cell (e.g., the target secondary cell or cell group assigned to {A1, B1, C1}), and

[0171] ii) handover configuration information indicating a handover configuration (e.g., a CHO configuration) for performing a handover to a target cell of the target node 320-5.

[0172] In the example of Figure 3 , the target secondary cell information indicates a request to duplicate the new measurement(s) (e.g., {A, B, C}) with the different measurement identifier(s) (e.g., {A1, B1, C1}) in the source configuration. The source 320-2 can then configure the UE to the objects of {A1, B1, C1} for the early measurement(s) based at least in part on this target secondary cell information by transmitting, e.g., a modified measurement configuration.

[0173] The request information (e.g., HO-REQ-ACK) can include or comprise a list of measurement identifiers indicating measurement configurations for measurements of respective target secondary cells or target secondary cell groups of the target node. Further, the source configured measurement configuration information can include or comprise a list of respective measurement identifiers. In this way, the source can trigger the UE to perform measurements on several candidate target PSCells related to the target node.

[0174] Figures 4a-4b is a signaling diagram 400 illustrating another example of how an exemplary procedure of a conditional handover of a UE 430 between a source gNB 420-3 and a target gNB 420-5 can be performed. Figure 4a The upper (first) part 400a of the diagram 400 is illustrated, Figure 4b The lower (second) part 400b of the diagram 400 is illustrated. For the sake of clarity, the labels of the respective entities “UE”, “source”, etc. are repeated in Figure 4b .

[0175] For example, the UE 130 can be configured as the UE 430, the source gNB 120-3 can be configured as the gNB 420-3, and / or the target gNB 120-5 can be configured as the gNB 420-5.

[0176] Figures 4a-4b Another example embodiment of a method according to the first exemplary aspect is also illustrated, and another example embodiment of a method according to the second exemplary aspect is also illustrated. Further, the UE 430 can be another example embodiment of an apparatus according to the first exemplary aspect. Further, the source gNB 420-3 can be another example embodiment of an apparatus according to the second exemplary aspect.

[0177] Figures 4a-4b The procedure in can comprise some or all of the following steps:

[0178] Step 431 : This step corresponds to step 331 in Figure 3 .

[0179] Step 432: This step corresponds to step 332 in Figure 3 .

[0180] Step 433: This step corresponds to step 333 in Figure 3 . In this example embodiment, the RRC reconfiguration does not include a CPA configuration.

[0181] Step 434: This step corresponds to step 334 in Figure 3 .

[0182] Step 435: This step corresponds to step 335 in Figure 3 .

[0183] Step 436: In this step, the source node 430-3 can transmit an RRC reconfiguration to the UE, which includes a CHO configuration and preferences for target PSCells (e.g., PSCell_1 and PSCell_2).

[0184] Step 437: This step corresponds to step 336 in Figure 3 .

[0185] Step 438: This step corresponds to step 212 in Figures 2a-2b .

[0186] Step 439: The target node can transmit a random access response (RAR) in response to the PRACH (see also step 213 in Figures 2a-2b ).

[0187] Step 440: The UE 430 then transmits an RRCReconfigurationComplete to the target node 420-5 (as in step 214 in Figures 2a-2b ). In this example embodiment, the RRCReconfigurationComplete includes measurement results for candidate target PSCells when option 2 is used.

[0188] Step 441: The target node 420-5 decides whether to activate DC based at least in part on the measurement results for candidate target PSCells received in step 440.

[0189] Step 442: If the target node 420-5 decides to activate DC in step 441, the target node 420-5 can then transmit an activate DC command / configuration (including RRC configuration with SCG) to the UE 430. In this way, the target PCell can add the DC configuration by sending an RRC reconfiguration with secondary cell group configuration to the UE.

[0190] Step 443: The UE 430 activates DC.

[0191] Step 444: The UE 430 transmits a PRACH to the selected target secondary node 420-7 (target PSCell).

[0192] Steps can be followed that correspond to steps 543 and 544 as described below.

[0193] Figures 4a-4bAn example is shown where the report of the measurements is included in the HO completion message (e.g. RRCReconfigurationComplete).

[0194] If the measurement results are included or comprise in the HO completion message (e.g. RRCReconfigurationComplete), one or more of the following can be performed and / or controlled:

[0195] - The source node can configure measurement IDs for event-based reporting of measurement objects for potential target PSCell frequencies. There can be multiple such measurement identifiers for different PSCell frequencies of the target node.

[0196] - As part of the HO preparation, the target node can select a subset of the measurement IDs it needs in e.g. Msg3, as the target can be targeting DC or Carrier Aggregation (CA)

[0197] establishing taking into account these measurement IDs

[0198] - In one example, the target node can provide a “preferred measurement ID” for early reporting in the HO-REQ-ACK.

[0199] - In another example, the source node can include a “preferred measurement ID” for early reporting,

[0200] instead of all results for PSCells (see also Figures 5a-5b ).

[0201] During CHO execution, the available mapped measurements can be transferred to the target node 420-5. Then, the DC configuration can be sent by the new source (i.e. the former target node 420-5) based on the measurements.

[0202] Figures 4a-4b The example shown includes an exemplary embodiment of a method according to the first exemplary aspect. In particular, in this example, the UE 430 can be an apparatus according to the first aspect.

[0203] The UE 430 (which can be a mobile device, such as a cellular phone) comprises at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the UE at least to perform the following operations:

[0204] - In step 433, an RRC reconfiguration is acquired from the source node 420-3, the RRC reconfiguration comprising at least one of e.g.:

[0205] i) measurement configuration information indicating a measurement configuration, e.g. a modified measurement configuration {A1, B1, C1}, for measurements of at least one target secondary cell, e.g. of a target secondary cell group comprising the at least one target secondary cell,

[0206] measurement configuration, e.g. a modified measurement configuration {A1, B1, C1}; and

[0207] ii) handover configuration information, e.g. a CHO configuration, indicating a handover configuration for performing a handover to a target cell of the target node 420-5,

[0208] performing a handover from a source cell of the source node 420-3 to a target cell of the target node 420-5 based at least in part on the handover configuration information, and

[0209] starting measurements of at least one target secondary cell, e.g. of a target secondary cell group comprising the at least one target secondary cell, based at least in part on the measurement configuration information, e.g. by creating a new measurement object / measurement report / measurement identifier and mapping it to a given target PSCell frequency in step 434, before and / or during performing the handover.

[0210] Figures 4a-4b The illustrated example also includes an exemplary embodiment of a method according to the second exemplary aspect. In particular, in this example, the source node 420-3 can be or can be part of an apparatus according to the second aspect.

[0211] The source node 420-3 comprises at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the source node at least to perform the following operations:

[0212] receiving, from the target node 420-5, target secondary cell information indicating at least one target secondary cell, e.g. a target secondary cell group comprising the at least one target secondary cell, e.g. a HO-REQ-ACK, in step 432,

[0213] transmitting, to the UE 430, an RRC configuration, e.g. an RRC reconfiguration, including at least one of the following, e.g. a modified measurement configuration {A1, B1, C1} and a handover configuration, e.g. a CHO configuration, indicating a handover configuration for performing a handover to a target cell of the target node 420-5, in step 433 upon receiving the target secondary cell information, e.g. the HO-REQ-ACK,

[0214] i) measurement configuration information indicating a measurement configuration, e.g. a modified measurement configuration {A1, B1, C1}, for measurements of at least one target secondary cell, e.g. of a target secondary cell group comprising the at least one target secondary cell,

[0215] ii) handover configuration information indicating a handover configuration (e.g., CHO configuration) for performing a handover to a target cell of the target node 420-5.

[0216] Figures 5a-5b is a signaling diagram 500 illustrating another example of an exemplary procedure of how to perform a conditional handover of a UE 530 between a source gNB 520-3 and a target gNB 520-5. Figure 5a The upper (first) part 500a of the diagram 500 is illustrated, Figure 5b The lower (second) part 500b of the diagram 500 is illustrated. For the sake of clarity, the labels of the respective entities “UE”, “source”, etc. are repeated in Figure 5b .

[0217] For example, the UE 130 can be configured as the UE 530, the source gNB 120-3 can be configured as the gNB 520-3, and / or the target gNB 120-5 can be configured as the gNB 520-5.

[0218] Figures 5a-5b Another example embodiment of a method according to the first exemplary aspect is also illustrated, and another example embodiment of a method according to the second exemplary aspect is also illustrated. Furthermore, the UE 530 can be another example embodiment of an apparatus according to the first exemplary aspect. Furthermore, the source gNB 520-3 can be another example embodiment of an apparatus according to the second exemplary aspect.

[0219] Figures 5a-5b The procedure in comprises the following steps:

[0220] Step 531 : This step corresponds to step 431 in Figures 4a-4b .

[0221] Step 532: This step corresponds to step 432 in Figures 4a-4b .

[0222] Step 533: This step corresponds to step 333 in Figure 3 . Unlike step 433 in Figures 4a-4b , the RRC reconfiguration in this exemplary embodiment comprises a CPA configuration.

[0223] Step 534: This step corresponds to step 434 in Figures 4a-4b .

[0224] Step 535: This step corresponds to step 435 in Figures 4a-4b .

[0225] Step 536: This step corresponds to step 436 in Figures 4a-4b .

[0226] Step 537: This step corresponds to step 437 in Figures 4a-4b .

[0227] Step 538: This step corresponds to step 438 in Figures 4a-4b .

[0228] Step 539: This step corresponds to step 439 in Figures 4a-4b .

[0229] Step 540: This step corresponds to step 440 in Figures 4a-4b . In case of Option 2, the RRCReconfigurationComplete can include the measurement results of the candidate PSCells.

[0230] Step 541 : According to Option 3, the UE 530 can continue the measurements of the candidate PSCells during and / or after the CHO. The UE 530 does not need to report the measurement results to the target node 520-5. Since the UE in this example receives the CPA configuration in step 533, the UE can continue the measurements of the candidate PSCells during and / or after the CHO and perform the CPA when the CPA condition is fulfilled.

[0231] Step 542: This step corresponds to step 444 in Figures 5a-5b .

[0232] Step 543: The target secondary node 520-7 (PSCell) responds to the PRACH by transmitting a RAR to the UE 530.

[0233] Step 544: The UE 530 transmits a RRCReconfigurationComplete to the target secondary node 520-7.

[0234] In one example, if the measurement results of the source are linked to a conditional PSCell addition, the measurement results of the source are further continued in the target after the handover. For example, in this case, the reporting of the measurements in the handover complete is not needed anymore.

[0235] Figures 5a-5b The illustrated example includes an exemplary embodiment of a method according to the first exemplary aspect. In particular, in this example, the UE 530 can be an apparatus according to the first aspect.

[0236] The UE 530 (which can be a mobile device, such as a cellular phone) comprises at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the UE at least to perform the following operations:

[0237] - in step 533, obtaining an RRC reconfiguration from the source node 520-3, the RRC reconfiguration comprising, for example, at least one of:

[0238] i) measurement configuration information indicating measurements on at least one target secondary cell (e.g., measurements on a target secondary cell group comprising the at least one target secondary cell),

[0239] a measurement configuration, e.g., modifying the measurement configuration {A1, B1, C1}; and

[0240] ii) handover configuration information, e.g., CHO configuration, indicating a handover configuration for performing a handover to the target node 520-5,

[0241] iii) CPA configuration information indicating a CPA configuration

[0242] - in step 537, performing a handover from a source cell of the source node 520-3 to a target cell of the target node 520-5 based at least in part on the handover configuration information,

[0243] - prior to and / or during performing the handover, in step 535, starting measurements on at least one target secondary cell (e.g., on a target secondary cell group comprising the at least one target secondary cell) based at least in part on the measurement configuration information, e.g., by creating a new measurement object / measurement report / measurement identifier in step 534 and mapping it to a given target PSCell frequency.

[0244] Figures 5a-5b The illustrated example also includes an exemplary embodiment of a method according to the second exemplary aspect. In particular, in this example, the source node 520-3 can be or can be part of an apparatus according to the second aspect.

[0245] The source node 520-3 comprises at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, with the at least one processor, cause the source node at least to perform the following operations:

[0246] - in step 532, receiving target secondary cell information from the target node indicating at least one target secondary cell (e.g.,

[0247] a target secondary cell group comprising the at least one target secondary cell,

[0248] e.g., a HO-REQ-ACK,

[0249] - upon receiving the request information (e.g., the HO-REQ-ACK), in step 533, transmitting an RRC configuration (e.g., an RRC reconfiguration) to the UE 530, the RRC configuration comprising, for example:

[0250] i) measurement configuration information indicating a measurement configuration for measurements of at least one target secondary cell (e.g., a target secondary cell or cell group assigned to {A1, B1, C1}) based at least in part on target secondary cell information (e.g., HO-REQ-ACK), e.g., modifying the measurement configuration,

[0251] ii) handover configuration information indicating a handover configuration (e.g., CHO configuration) for performing a handover to a target cell of the target node 520-5, and

[0252] iii) CPA configuration information indicating a CPA configuration.

[0253] For example, the measurement results of the source node 520-3 can be further continued in the target node 520-5 after the handover, e.g., in case it links to a conditional PSCell addition. In this case, the reporting of the measurements in the handover completion can be omitted. Such an example is also shown in Figures 5a-5b as “Option 3”.

[0254] Figures 4a-4b An example is shown where the CPA is included in the CHO configuration. Here, the UE 530 can continue measurements during and / or after the CHO target is accessed to find a potential PSCell.

[0255] In another example, the CHO configuration can also include conditions for which PSCells to start “relevant early measurements”, instead of blindly starting early measurements for all PSCells. The UE can only start measurements for PSCell candidates configured by the target cell (see Figures 5a-5b and Figure 6 “Option 2” in) which are possible CHO execution candidates. This “possibility” can be implemented using another intermediate measurement threshold, allowing the UE to determine that the cell is a possible target for which its CHO condition will trigger.

[0256] In another example, the UE / IoT device can follow an approach where the measurements are performed in steps, i.e., starting from a coarse initial setup and gradually increasing the frequency of these measurements. This will alleviate the measurement burden of the UE. Similarly, for those cases where the threshold is not met, the situation is just the opposite, i.e., the measurements are performed in a more relaxed way.

[0257] In another example, the target node gives a measurement related configuration, but it does not contain the CPA configuration. In this case, the target node informs the source node to include this measurement ID in the source configuration. In this case, first the PCell HO is triggered, then the new source will send the CPA configuration, which will be applied immediately afterwards. These are the measurements that are done before and / or during CHO execution. In other words, in this case, the UE will provide the measurement results in the target node as soon as possible after the HO (CHO or regular) in order to allow the NW to configure the DC / CA as soon as possible after the HO, i.e. the UE will provide the measurement results e.g. already in the HO complete message). For this approach, the source node can also provide a list of measurement IDs whose measurement results are relevant for the target node for e.g. SN addition or CPA decision.

[0258] For example, in order to perform SN addition / CPA faster (e.g. for fast DC setup and configuration on the target side), some early / earlier measurements on (candidate) target SCG can be started from the source itself (e.g. before and / or during the CHO execution is triggered, while the UE is still served by the source cell). This means that the UE can already start performing candidate (P)SCell measurements before and / or during CHO execution to the target node.

[0259] In another example, the CHO configuration also contains or comprises the CPA configuration. In this case, the target node informs the source node to include or comprise this measurement ID in the source configuration, the delay trigger condition after handover execution. That is, the PCell HO should be triggered first, then any PSCell addition execution or CPA can be done without (e.g. explicit) new or additional signaling from the new source regarding the CPA configuration. This is the case for one or more SCG setup CPA configuration.

[0260] In another example, the measurement results of the new measurement ID added in the RRC reconfiguration containing or comprising the CHO configuration are also mapped to the measurement ID in the target measurement configuration linked to the conditional PSCell addition. For example, the measurement ID linked to the conditional PSCell addition will result in triggering a measurement report to the target MN to prepare the SN as part of the CPA procedure after the handover.

[0261] Figure 1 is a schematic block diagram of an apparatus 600 according to exemplary aspects, which may, for example, represent Figure 1 a mobile device 130 of

[0262] The apparatus 600 comprises a processor 610, a working memory 620, a program memory 630, a data memory 640, a communication interface(s) 650, an optional user interface 660, and an optional sensor(s) 670.

[0263] The apparatus 600 can for example be configured to perform and / or control a method according to the first exemplary aspect or comprise respective means (at least one of 610 to 670) for performing and / or controlling a method according to the first exemplary aspect. The apparatus 600 comprises at least one processor (610) and at least one memory (620) including a computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus (e.g., apparatus 600) at least to perform and / or control a method according to the first exemplary aspect.

[0264] The processor 610 can for example comprise an information acquirer 611 as a functional and / or structural unit. The information acquirer 611 can for example be configured to acquire (e.g., retrieve) respective information, such as measurement configuration information, handover configuration information, RRC configuration, CPA configuration information, or a combination thereof, to name a few non-limiting examples.

[0265] The processor 610 can for example comprise a handover executor 612 as a functional and / or structural unit. The handover executor 612 can for example be configured to execute (e.g., perform and / or control) a handover.

[0266] The processor 610 can for example comprise a measurement starter 613 as a functional and / or structural unit. The measurement starter 613 can for example be configured to start measurements on a target secondary cell before and / or during execution of a handover.

[0267] The processor 610 can for example further control the memories 620 to 640, the communication interface(s) 650, the optional user interface 660, and the optional sensor(s) 670.

[0268] The processor 610 can for example execute computer program code stored in the program memory 630, which can for example represent a computer-readable storage medium including program code which, when executed by the processor 610, causes the processor 610 to perform a method according to the first exemplary aspect.

[0269] The processor 610 (as well as any other processor mentioned in this description) can be any suitable type of processor. The processor 610 can include, but is not limited to, one or more microprocessors, one or more processors with accompanying digital signal processors, one or more (multi-core) processors and accompanying graphics processing units (GPUs), one or more processors with accompanying quantum chips, one or more application-specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more controllers, one or more microcontrollers, one or more

[0270] A program memory 630 can also be included in the processor 610. This memory can for example be fixedly connected to the processor 610 or at least partly removable from the processor 610, for example in the form of a memory card or stick. The program memory 630 can for example be a non-volatile memory. For example, it can be any of a FLASH memory (or a part thereof), a ROM, a PROM, an EPROM and EEPROM memory (or a part thereof), or a hard disk (or a part thereof), to name a few examples. The program memory 630 can also include an operating system for the processor 610. The program memory 630 can also include firmware for the apparatus 600.

[0271] The apparatus 600 includes a working memory 620, for example in the form of a volatile memory. It can be a random access memory (RAM) or a dynamic RAM (DRAM), to name a few non-limiting examples. It can for example be used by the processor 610 when executing an operating system and / or a computer program.

[0272] The data memory 640 can for example be a non-volatile memory. For example, it can be any of a FLASH memory (or a part thereof), a ROM, a PROM, an EPROM and EEPROM memory (or a part thereof), or a hard disk (or a part thereof), to name a few examples. The data memory 640 can for example store measurement configuration information, handover configuration information, RRC configuration, CPA configuration information, or a combination thereof, to name a few non-limiting examples.

[0273] The communication interface(s) 650 enable the apparatus 600 to communicate with other entities, for example with the gNBs 120-1 to 120-7 of the Figure 1 The communication interface(s) 650 can for example include a wireless interface (for example a cellular radio communication interface and / or a WLAN interface) and / or a wired interface (for example an IP-based interface), for example to communicate with entities via the Internet. The communication interface(s) can enable the apparatus 600 to communicate with other entities not shown in the Figure 7 Fig. 1.

[0274] The user interface 660 is optional and can include a display for displaying information to a user and / or an input device (e.g., a keyboard, a keypad, a touchpad, a mouse, etc.) for receiving information from a user.

[0275] The sensor(s) 670 are optional and can for example include a barometric pressure sensor for collecting pressure information.

[0276] Some or all of the components of the apparatus 600 can be connected, e.g., via a bus. Some or all of the components of the apparatus 600 can for example be combined into one or more modules.

[0277] Figure 1 is a schematic block diagram of an apparatus 700 according to an exemplary aspect, which can for example represent Figure 1 one of the gNBs 120-1 to 120-7 of Fig. 1.

[0278] The apparatus 700 comprises a processor 710, a working memory 720, a program memory 730, a data memory 740, a communication interface(s) 750 and an optional user interface 760.

[0279] The apparatus 700 can for example be configured to perform and / or control a method according to the second exemplary aspect or comprise corresponding means (at least one of 710 to 760) for performing and / or controlling a method according to the second exemplary aspect. The apparatus 700 can further constitute a kind of apparatus comprising at least one processor (710) and at least one memory (720) including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus (e.g., apparatus 700) at least to perform and / or control a method according to the second exemplary aspect.

[0280] The processor 710 can for example comprise a measurement result mapper 711 as a functional and / or structural unit. The measurement result mapper 711 can for example be configured to map one or more measurement results.

[0281] The processor 710 can for example further control the memories 720 to 740, the communication interface(s) 750, the optional user interface 760 and the optional sensor(s) 770.

[0282] The processor 710 can for example execute computer program code stored in the program memory 730, which can for example represent a computer-readable storage medium including program code which, when executed by the processor 710, causes the processor 710 to perform a method according to the second exemplary aspect.

[0283] The processor 710 (as well as any other processor mentioned in this description) can be any suitable type of processor. The processor 710 can include, but is not limited to, one or more microprocessors, one or more processors with accompanying digital signal processors, one or more (multi-core) processors and accompanying graphics processing units (GPUs), one or more processors with accompanying quantum chips, one or more application-specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more controllers, one or more microcontrollers, one or more

[0284] A program memory 730 can also be included in the processor 710. This memory can for example be fixedly connected to the processor 710 or at least partly removable from the processor 710, for example in the form of a memory card or stick. The program memory 730 can for example be a non-volatile memory. For example, it can be any of a FLASH memory (or a part thereof), a ROM, a PROM, an EPROM and EEPROM memory (or a part thereof), or a hard disk (or a part thereof), to name a few examples. The program memory 730 can also include an operating system for the processor 710. The program memory 730 can also include firmware for the apparatus 700.

[0285] The apparatus 700 includes a working memory 720, for example in the form of a volatile memory. It can be a random access memory (RAM) or a dynamic RAM (DRAM), to name a few non-limiting examples. It can for example be used by the processor 710 in executing an operating system and / or a computer program.

[0286] The data memory 740 can for example be a non-volatile memory. For example, it can be any of a FLASH memory (or a part thereof), a ROM, a PROM, an EPROM and EEPROM memory (or a part thereof), or a hard disk (or a part thereof), to name a few examples. The data memory 640 can for example store measurement configuration information, handover configuration information, RRC configuration, CPA configuration information, or a combination thereof, to name a few non-limiting examples.

[0287] The communication interface(s) 750 enable the apparatus 700 to communicate with other entities, for example with the mobile device 130 of the system 100. Figure 1 The communication interface(s) 750 can for example include a wireless interface (for example a cellular radio communication interface and / or a WLAN interface) and / or a wired interface (for example an IP-based interface), for example to communicate with entities via the Internet. The communication interface(s) can enable the apparatus 700 to communicate with other entities, for example with the mobile device 130 of the system 100. ​other gNBs 120-1 - 120-7.

[0288] The user interface 760 is optional and can include a display for displaying information to the user and / or an input device (e.g., keyboard, keypad, touchpad, mouse, etc.) for receiving information from the user.

[0289] Some or all of the components of the apparatus 700 can be connected, for example, via a bus. Some or all of the components of the apparatus 700 may, for example, be combined into one or more modules.

[0290] It should also be contemplated to disclose the following embodiments:

[0291] Embodiment 1 :

[0292] A method comprising:

[0293] - obtaining measurement configuration information indicative of a measurement configuration for measurements of at least one target secondary cell of a mobile communication network,

[0294] - performing a handover to a target cell,

[0295] - starting measurements of at least one target secondary cell based at least partly on the measurement configuration information prior to and / or during performing the handover.

[0296] Embodiment 2:

[0297] The method according to embodiment 1, wherein

[0298] - the handover is a handover from a source cell of the mobile communication network to the target cell, and

[0299] - obtaining the measurement configuration information comprises receiving the measurement configuration information from a source node.

[0300] Embodiment 3:

[0301] The method according to embodiment 1 or 2, further comprising:

[0302] - obtaining handover configuration information indicative of a handover configuration for performing a handover to the target cell.

[0303] Embodiment 4:

[0304] The method according to embodiment 3, wherein:

[0305] - obtaining the measurement configuration information and the handover configuration information comprises receiving a radio resource control, RRC, configuration, the RRC configuration comprising the measurement configuration information and the handover configuration information.

[0306] Embodiment 5:

[0307] The method according to embodiment 4, wherein:

[0308] - the RRC configuration further comprises a conditional PSCell addition (CPA) configuration.

[0309] Embodiment 6:

[0310] The method according to any one of embodiments 1 to 5, further comprising:

[0311] - obtaining the CPA configuration after performing the handover to the target cell.

[0312] Embodiment 7:

[0313] The method according to any one of embodiments 1 to 6, wherein

[0314] - the measurement configuration information indicates one or more measurement identifiers, ID, each measurement ID indicating a measurement configuration for measurement of a respective target secondary cell.

[0315] Embodiment 8:

[0316] The method according to embodiment 7, further comprising:

[0317] - mapping the measurement results of the measurement identifiers to target measurement identifiers in a target measurement configuration.

[0318] Embodiment 9:

[0319] The method according to any one of embodiments 1 to 8, further comprising:

[0320] - transmitting measurement result information indicating the results of the measurements after the performance of the handover.

[0321] Embodiment 10:

[0322] The method according to embodiment 9, further comprising:

[0323] - transmitting a handover completion message indicating completion of the handover after the performance of the handover, wherein the handover completion message comprises the measurement result information.

[0324] Embodiment 11:

[0325] The method according to any one of embodiments 6 to 10, further comprising:

[0326] - activating dual connectivity based at least in part on the CPA configuration after the performance of the handover.

[0327] Embodiment 12:

[0328] The method according to any one of embodiments 1 to 11, wherein the acquiring measurement configuration information, the performing the handover and / or the starting the measurements are performed on or with a mobile device and / or an Internet of Things, loT, device.

[0329] Embodiment 13:

[0330] A method comprising:

[0331] - receiving target secondary cell information from a target node, the target secondary cell information indicating at least one target secondary cell,

[0332] - upon receiving the target secondary cell information, transmitting measurement configuration information based at least partly on the target secondary cell information, the measurement configuration information indicating a measurement configuration for measurements of at least one target secondary cell.

[0333] Embodiment 14:

[0334] The method according to embodiment 13, wherein:

[0335] - the target secondary cell information and / or the measurement configuration information comprises one or more measurement identifiers.

[0336] Embodiment 15:

[0337] The method according to embodiment 14, further comprising:

[0338] - mapping the measurement identifiers to source measurement identifiers in a source measurement configuration.

[0339] Embodiment 16:

[0340] The method according to any one of embodiments 13 to 15, further comprising:

[0341] - after transmitting the measurement configuration information, receiving handover success information indicating a successful handover to the target node.

[0342] Embodiment 17:

[0343] The method according to any one of embodiments 13 to 16, wherein the method is performed on or with a source primary node of the mobile communication network.

[0344] Embodiment 18:

[0345] A tangible computer-readable medium storing computer program code which, when executed by a processor, causes an apparatus to perform and / or control:

[0346] - acquiring measurement configuration information indicating a measurement configuration for measurements of at least one target secondary cell of a mobile communication network,

[0347] - performing a handover to a target cell, and

[0348] - starting measurements of at least one target secondary cell based at least partly on the measurement configuration information before and / or during performing the handover.

[0349] Embodiment 19:

[0350] The tangible computer-readable medium according to embodiment 18, the computer program code which, when executed by the processor, causes the apparatus to perform and / or control:

[0351] - the handover is a handover from a source cell of the mobile communication network to the target cell, and

[0352] - obtaining the measurement configuration information comprises receiving the measurement configuration information from a source node.

[0353] Embodiment 20:

[0354] The tangible computer-readable medium according to embodiment 18 or 19, the computer program code which, when executed by the processor, causes the apparatus to perform and / or control:

[0355] - obtaining handover configuration information indicating a handover configuration for performing a handover to the target cell.

[0356] Embodiment 21:

[0357] The tangible computer-readable medium according to any of embodiment 20, the computer program code which, when executed by the processor, causes the apparatus to perform and / or control:

[0358] - obtaining the measurement configuration information and the handover configuration information comprises receiving a radio resource control, RRC, configuration, the RRC configuration comprising the measurement configuration information and the handover configuration information.

[0359] Embodiment 22:

[0360] The tangible computer-readable medium according to embodiment 21, the computer program code which, when executed by the processor, causes the apparatus to perform and / or control:

[0361] - the RRC configuration further comprises a conditional PSCell addition, CPA, configuration.

[0362] Embodiment 23:

[0363] The tangible computer-readable medium according to any of embodiments 18 to 22, the computer program code which, when executed by the processor, causes the apparatus to perform and / or control:

[0364] - obtaining a CPA configuration after performing the handover to the target cell.

[0365] Embodiment 24:

[0366] The tangible computer-readable medium according to any one of embodiments 18 to 23, the computer program code which, when executed by the processor, causes the apparatus to perform and / or control:

[0367] - the measurement configuration information indicates one or more measurement identifiers, ID, each measurement ID indicating a measurement configuration for measurement of a respective target secondary cell.

[0368] Embodiment 25:

[0369] The tangible computer-readable medium according to embodiment 24, the computer program code which, when executed by the processor, causes the apparatus to perform and / or control:

[0370] - mapping the measurement results of the measurement identifiers to target measurement identifiers in a target measurement configuration.

[0371] Embodiment 26:

[0372] The tangible computer-readable medium according to any one of embodiments 18 to 25, the computer program code which, when executed by the processor, causes the apparatus to perform and / or control:

[0373] - transmitting measurement result information indicating results of the measurements after the performance of the handover.

[0374] Embodiment 27:

[0375] The tangible computer-readable medium according to embodiment 26, the computer program code which, when executed by the processor, causes the apparatus to perform and / or control:

[0376] - transmitting a handover completion message indicating completion of the handover after the performance of the handover, wherein the handover completion message comprises the measurement result information.

[0377] Embodiment 28:

[0378] The tangible computer-readable medium according to any one of embodiments 22 to 27, the computer program code which, when executed by the processor, causes the apparatus to perform and / or control:

[0379] - activating dual connectivity based at least partly on the CPA configuration after the performance of the handover.

[0380] Embodiment 29:

[0381] A tangible computer-readable medium storing computer program code which, when executed by a processor, causes an apparatus to perform and / or control:

[0382] - receiving target secondary cell information from a target node indicating at least one target secondary cell,

[0383] - upon receiving the target secondary cell information, transmitting measurement configuration information based at least in part on the target secondary cell information, the measurement configuration information indicating a measurement configuration for measurements of at least one target secondary cell.

[0384] Embodiment 30:

[0385] The tangible computer-readable medium according to embodiment 29, which, when executed by a processor, causes an apparatus to perform and / or control:

[0386] - the target secondary cell information and / or the measurement configuration information comprises one or more measurement identifiers.

[0387] Embodiment 31:

[0388] The tangible computer-readable medium according to embodiment 30, which, when executed by a processor, causes an apparatus to perform and / or control:

[0389] - mapping the measurement identifiers to source measurement identifiers in a source measurement configuration.

[0390] Embodiment 32:

[0391] The tangible computer-readable medium according to any one of embodiments 29 to 31, which, when executed by a processor, causes an apparatus to perform and / or control:

[0392] - after transmitting the measurement configuration information, receiving handover success information indicating a successful handover to the target node.

[0393] Embodiment 33:

[0394] An apparatus comprising at least one processor and at least one memory including computer program code which, when executed by the at least one processor, causes the apparatus at least to perform and / or control the method of the first exemplary aspect.

[0395] Embodiment 34:

[0396] An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform and / or control the method of the second exemplary aspect.

[0397] Thus, support for commercial use cases, including general commercial use cases and specifically (I)IoT use cases, can be implemented with example embodiments necessary enhancements and solutions for high accuracy (e.g., horizontal and / or vertical), low latency, network efficiency (scalability, RS overhead, etc.), and device efficiency (power consumption, complexity) requirements.

[0398] In this specification, any presented connection in the described embodiments should be understood in a way that the involved components are operatively coupled. Thus, the connection can be direct or indirect, using any number or combination of intermediary elements, and there can only be a functional relationship between the components.

[0399] Furthermore, any methods, processes and actions described or illustrated herein can be implemented using executable instructions stored in a computer readable storage medium (e.g., disk, memory, etc.) that are executed by a general purpose or special purpose processor. Reference to a "computer readable storage medium" should be understood to encompass special purpose circuits such as FPGAs, ASICs, signal processing devices and other devices.

[0400] The expression "A and / or B" is to be considered as including any one of the following three scenarios: (i) A, (ii) B, (iii) A and B. Furthermore, the article "a" is not to be construed as "one", i.e. the use of the expression "an element" does not exclude the presence of more than one element. The term "comprising" is to be construed as open, i.e. as "including", but not limited to, elements A.

[0401] It should be understood that all presented embodiments are exemplary and any feature presented for a particular example embodiment, either alone or in combination with any other feature presented for the same or another particular example embodiment, and / or in combination with any other feature not mentioned, can be used with any aspect of the application. In particular, the example embodiments presented in this description should also be understood to be disclosed in all possible combinations with each other, as long as this is technically reasonable and the example embodiments are not mutually exclusive alternatives. It will also be understood that any feature presented for an example embodiment in a particular category (method / arrangement / computer program / system) can also be used in a corresponding way for an example embodiment in any other category. It should also be understood that the presence of a feature in an example embodiment presented is not necessarily an indication that this feature forms an essential feature of the application and cannot be omitted or replaced.

[0402] The statement that a feature includes at least one of the subsequently listed features is not mandatory in the sense that the feature must include all of the subsequently listed features or at least one of the subsequently listed features. Furthermore, any combination of the listed features can be selected or one of the listed features can be selected. Specific combinations of all subsequently listed features can also be considered. Furthermore, a plurality of the listed features is also possible.

[0403] The order of all method steps described above is not mandatory and other orders can also be employed. However, the particular sequence of method steps, which is exemplarily shown in the figures, should be regarded as one possible sequence of method steps for the method of the respective embodiment described by the respective figure.

[0404] The application has been described above by way of example embodiments. It should be noted that alternative ways and modifications exist, which will be clear to the person skilled in the art and which can be implemented without departing from the scope of the appended claims.

[0405] With the application and its different aspects described herein, for example one or more of the following can be achieved:

[0406] - support fast establishment and configuration of DC in candidate target gNBs,

[0407] - target node can better decide whether to activate DC based on early measurements,

[0408] - target can have more accurate knowledge of the measurements needed to configure and activate DC.

Claims

1. An apparatus for communication, comprising at least one processor and at least one memory including computer program code, said at least one memory and said computer program code being configured together with said at least one processor to cause the apparatus to perform at least the following: Measurement configuration information is obtained from the source master node, indicating the measurement configuration for at least one target secondary cell of the mobile communication network. Obtain handover configuration information that indicates the handover configuration to be performed to the target cell. The acquisition of the measurement configuration information and the switching configuration information includes: Receive Radio Resource Control (RRC) configuration, the RRC configuration including the measurement configuration information and the handover configuration information, the RRC configuration also including Conditional PSCell Addition (CPA) configuration; Perform a handover from the source master cell of the source master node to the target master cell of the target master node. Before and / or during the handover, measurements of at least one target secondary cell are initiated at least in part based on the measurement configuration information, and after the handover is performed, measurement result information indicating the results of the measurements is transmitted to the target primary node; as well as After performing the handover to the target cell, obtain the CPA configuration.

2. The apparatus according to claim 1, wherein... The handover is a handover from the source cell to the target cell of the mobile communication network, and Obtaining the measurement configuration information includes: Receive the measurement configuration information from the source master node.

3. The apparatus according to claim 1 or 2, wherein The measurement configuration information indicates one or more measurement identifiers (IDs), each measurement ID indicating the measurement configuration for the corresponding target secondary cell.

4. The apparatus of claim 3, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to further perform: Map the measurement results of the measurement identifier to the target measurement identifier in the target measurement configuration.

5. The apparatus of claim 1 or 2, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to further perform: The reconfiguration completion message transmits measurement result information indicating the result of the measurement.

6. The apparatus of claim 1 or 2, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to further perform: After the handover is performed, a handover completion message indicating the completion of the handover is transmitted, wherein the handover completion message includes the measurement result information.

7. The apparatus of claim 1, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to further perform: After the switch is performed, dual connectivity is activated at least in part based on the CPA configuration.

8. The apparatus according to claim 1 or 2, wherein the apparatus is a mobile device and / or an Internet of Things (IoT) device, or is part of a mobile device and / or an IoT device.

9. An apparatus for communication, comprising at least one processor and at least one memory including computer program code, said at least one memory and said computer program code being configured together with said at least one processor to cause the apparatus to perform at least the following: Receive target secondary cell information indicating at least one target secondary cell from the target primary node. Upon receiving the target secondary cell information, the user equipment transmits Radio Resource Control (RRC) configuration at least in part based on the target secondary cell information. The RRC configuration includes measurement configuration information, handover configuration information, and Conditional PSCell Addition (CPA) configuration. The measurement configuration information indicates a measurement configuration for measurements of at least one target secondary cell. The handover configuration information indicates a handover configuration for performing a handover to the target cell. The measurement configuration causes the user equipment to transmit measurement result information indicating the results of measurements of the at least one target secondary cell after performing a handover from the source primary cell of the source primary node to the target primary cell of the target primary node. The target secondary cell information and the measurement configuration information include one or more measurement identifiers; Map the measurement identifier to the source measurement identifier in the source measurement configuration; After transmitting the measurement configuration information, a successful handover message indicating a successful handover to the target master node is received.

10. The apparatus of claim 9, wherein the apparatus is a source master node of a mobile communication network, or a part of the source master node.

11. A system for communication, comprising: At least one device according to any one of claims 1 to 8; as well as At least one device according to any one of claims 9 to 10.

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