Systems and methods for network triggered activation of conditional handover execution conditions

Abstract

A method (100) performed by a gNodeB Central Unit, gNB-CU, for configuring a conditional mobility procedure includes triggering (102) activation of at least one execution condition for the conditional mobility procedure for at least one User Equipment, UE (312) For example, triggering the activation of the at least one execution condition may include transmitting, to a gNodeB Distributed Unit, gNB-DU, a first indication to activate the at least one execution condition for the conditional mobility procedure. Additionally or alternatively, the triggering activation of the at least one execution condition may include transmitting, to the at least one UE, a second indication to activate the at least one execution condition for the conditional mobility procedure.

Description

[0001] SYSTEMS AND METHODS FOR NETWORK TRIGGERED ACTIVATION OF

[0002] CONDITIONAL HANDOVER EXECUTION CONDITIONS

[0003] TECHNICAL FIELD

[0004] The present disclosure relates, in general, to wireless communications and, more particularly, systems and methods for network triggered activation of Conditional Handover execution conditions.

[0005] BACKGROUND

[0006] FIGURE 1 illustrates the 5G Radio Access Network architecture, as described in 3GPP TS 38.401 vl8.0.0. The 5G RAN architecture is also referred to as a Next Generation-RAN (NG-RAN) architecture and consists of a set of gNodeBs (gNBs) connected to the 5G Core (5GC) through the NG interface.

[0007] As specified in 3GPP TS 38.300, the NG-RAN could also consist of a set of Next Generation-eNodeBs (ng-eNBs). An ng-eNB may consist of an ng-eNB Central Unit (ng-eNB- CU) and one or more ng-eNB Distributed Units (ng-eNB-DUs). An ng-eNB-CU and an ng- eNB-DU are connected via W1 interface. The principles described herein apply to ng-eNB and W1 interface, if not explicitly specified otherwise.

[0008] A gNB can support Frequency Division Duplex (FDD) mode, Time Division Duplex (TDD) mode, or dual mode operation. gNBs can be interconnected through the Xn interface. A gNB may consist of a gNB Central Unit (gNB-CU) and one or more gNB Distributed Units (gNB-DUs). A gNB-CU and a gNB-DU are connected via the Fl interface. One gNB-DU is connected to only one gNB-CU. NG, Xn, and Fl are logical interfaces.

[0009] For NG-RAN, the NG and Xn-C interfaces for a gNB consisting of a gNB-CU and gNB-DUs, terminate in the gNB-CU. For Evolved-UMTS Terrestrial Radio Access Network New Radio - Dual Connectivity (EN-DC), the S 1-U and X2-C interfaces for a gNB consisting of a gNB-CU and gNB-DUs terminate in the gNB-CU. The gNB-CU and connected gNB-DUs are only visible to other gNBs and the 5GC as a gNB.

[0010] FIGURE 2 illustrates the overall architecture for separation of gNB-CU-Control Plane (gNB-CU-CP) and gNB-CU-User Plane (gNB-CU-UP). A gNB may consist of a gNB-CU-CP, multiple gNB-CU-UPs and multiple gNB-DUs. The gNB-CU-CP is connected to the gNB-DU through the Fl-C interface. The gNB-CU-UP is connected to the gNB-DU through the Fl-U interface. The gNB-CU-UP is connected to the gNB-CU-CP through the El interface. One gNB-DU is connected to only one gNB-CU-CP. One gNB-CU-UP is connected to only one gNB-CU-CP.

[0011] It is noted that the architectures shown in FIGURE 1 and FIGURE 2 are depicted as defined for 5G by Third Generation Partnership Project (3GPP). Other standardization groups, such as the 0-RAN Alliance, have further extended the architecture above and have for example split the gNB-DU into two further nodes connected by a fronthaul interface. The lower node of the split gNB-DU would contain the PHY protocol and the RF parts, the upper node of the split gNB-DU would host the RLC and MAC. In 0-RAN the upper node is called O- DU, while the lower node is called O-RU.

[0012] Conditional HO for Network Energy Saving

[0013] 3GPP TS 38.300 vl8.1.0 section 9.2.3.4 provides a high-level description for Conditional Handover, as described below:

[0014] A Conditional Handover (CHO) is defined as a handover that is executed by the UE when one or more handover execution conditions are met. The UE starts evaluating the execution condition(s) upon receiving the CHO configuration and stops evaluating the execution condition(s) once a handover is executed.

[0015] The following principles apply to CHO:

[0016] - The CHO configuration contains the configuration of CHO candidate cell(s) generated by the candidate gNB(s) and execution condition(s) generated by the source gNB.

[0017] - An execution condition may consist of one or two trigger condition(s) (CHO events A3 / A5, as defined in

[0012] ). Only single RS type is supported and at most two different trigger quantities (e.g. RSRP and RSRQ, RSRP and SINR, etc.) can be configured simultaneously for the evaluation of CHO execution condition of a single candidate cell.

[0018] - Before any CHO execution condition is satisfied, upon reception of HO command (without CHO configuration), the UE executes the HO procedure, regardless of any previously received CHO configuration. - While executing CHO, i.e. from the time when the UE starts synchronization with target cell, UE does not monitor source cell.

[0019] In case the source cell is using a network energy saving solution, 3GPP TS 38.300 vl8.1.0, in section 15.4.2.4 indicates that the same principle as described in 9.2.3.4 applies and one or more UEs may use Network Energy Saving (NES), specific CHO event for executing CHO to a candidate cell:

[0020] The same principle as described in 9.2.3.4 applies to conditional handover in case the source cell is using a network energy saving solution (e.g., the cell is activating cell DTX / DRX or turning off), unless hereunder specified. In this case, the following additional triggering conditions are supported, upon which UE may use NES-specific CHO event for executing CHO to a candidate cell, as defined in TS 38.331:

[0021] The UE may be notified via DCI to enable CHO conditions(s) configured with NES event indication.

[0022] In TS 38.331 vI8.1.0, the nesEvent-rl8 IE is described as an extension of the CondTriggerConfig-rl 6 1 E. The description for the nesEvent-rl8 IE states that it “indicates the event is a NES-specific CHO event and the event is only considered to be satisfied if indication from lower layers is received indicating the applicability of NES-specific CHO event and the related entry condition(s) is fulfilled. This field can only be configured for condEventA3, condEventA4 or condEventA5.”

[0023] Section 7.3.1.3.10 of 3GPP TS 38.212 vl8.2.0 specifies that DCI format 2_9 can be used to indicate NES-specific CHO execution condition. With regard to DCI format 2 9, Section 11.5 of 3GPP TS 38.213 vl8.2.0 indicates the following: if nesEvent is configured, the NES-mode indication field includes one bit indicating NES-specific CHO execution condition

[0024] - a 'O' value for the NES-mode indication field indicates NES-specific CHO execution condition is disabled

[0025] - a T value for the NES-mode indication field, indicates NES-specific CHO execution condition is enabled

[0026] In other words, there is a flag in the DCI format 2_9 that allows the gNB to enable the execution of a CHO at a UE that has been prepared for CHO but with disabled / locked CHO execution condition(s). In a normal CHO, a UE starts monitoring the CHO execution condition(s) immediately after being configured with a CHO. In a CHO with a NES -specific CHO event (or NES CHO for simplicity), a UE needs to wait until the flag is set to ‘ 1’ before it starts monitoring the CHO execution condition(s).

[0027] There currently exist certain challenges, however. For example, in a gNB with split architecture, it is the gNB-CU that configures the NES CHO in a UE, and it is the gNB-DU that sends the DCI format 2 9. The assumption taken so far in 3GPP is that the conditions upon which the NES CHO execution conditions need to be activated are based on events controlled by the gNB-DU. For this reason, the gNB-DU has an independent say on when to signal to the UE a trigger for the activation of the configured NES CHO execution conditions. However, in some circumstances, the activation of the NES CHO execution conditions may depend on events and conditions under the control (or knowledge) of the gNB-CU. Therefore, the problem is that there is currently no way for the gNB-CU to trigger the activation of execution conditions or the execution of a conditional handover for selected UEs.

[0028] SUMMARY

[0029] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. For example, certain methods and systems enable the gNB-CU to control the activation of conditional handover execution conditions at a UE and / or trigger the UE for the execution of a handover procedure.

[0030] According to certain embodiments, a method by a gNB-CU for configuring a conditional mobility procedure includes triggering activation of at least one execution condition for the conditional mobility procedure for at least one UE.

[0031] According to certain embodiments, a gNB-CU for configuring a conditional mobility procedure includes a memory and a processor. The gNB-CU is configured to trigger activation of at least one execution condition for the conditional mobility procedure for at least one UE.

[0032] According to certain embodiments, a method by a gNB-DU for configuring a conditional mobility procedure includes receiving, from a gNB-CU, a first indication to activate at least one execution condition for the conditional mobility procedure for at least one UE. Additionally or alternatively, the method includes receiving, from the gNB-CU, a third indication that activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is pending until the first indication is received from the gNB- CU or until a second indication from the gNB-CU is received by the at least one UE.

[0033] According to certain embodiments, a gNB-DU for configuring a conditional mobility procedure includes a memory and a processor. The gNB-DU receives, from a gNB-CU, a first indication to activate at least one execution condition for the conditional mobility procedure for at least one UE. Additionally or alternatively, the gNB-DU also receives, from the gNB- CU, a third indication that activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is pending until the first indication is received from the gNB-CU or until a second indication from the gNB-CU is received by the at least one UE.

[0034] Certain embodiments may provide one or more of the following technical advantages. For example, certain embodiments may provide a technical advantage of enabling a gNB-CU to control or coordinate the activation of CHO execution conditions at a UE, e.g., for a UE configured with a NES CHO, depending on monitored performance metrics / indicators and / or predicted performance metrics / indicators from a neighborhood of network nodes.

[0035] As another example, certain embodiments make coordination with other RAN nodes possible since it is the gNB-CU that communicates with other gNBs. For example, the NES CHO could be used to coordinate the offloading of UEs (e.g., from a cell to be deactivated for energy savings reasons) to a number of neighboring gNBs. Additionally or alternatively, a technical advantage may be that the gNB-CU enables the execution of the NES CHO after receiving assistance information not available at the time of receiving the HANDOVER REQUEST ACKNOWLEDGE messages from the neighboring gNBs. The assistance information received by the gNB-CU may reveal that it is beneficial to execute the conditional handover because the overall performance of the nodes involved in the mobility action (source and target nodes) or the performance of a set of RAN nodes, e.g., a cluster, is optimized with respect to the case where the action is not executed. The performance of neighbouring gNBs can relate to measurements and / or predictions.

[0036] The teachings of certain embodiments may improve the data rate, latency, or power consumption.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] For a more complete understanding of the disclosed embodiments and their features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:

[0039] FIGURE 1 illustrates the 5G RAN architecture, as described in 3GPP TS 38.401 V18.0.0;

[0040] FIGURE 2 illustrates the overall architecture for separation of gNB-CU-CP and gNB- CU-UP;

[0041] FIGURE 3 illustrates an example method by a gNB-CU for configuring a conditional mobility procedure, according to certain embodiments;

[0042] FIGURE 4 illustrates an example method by a gNB-DU for configuring a conditional mobility procedure, according to certain embodiments;

[0043] FIGURE 5 illustrates an example communication system, according to certain embodiments;

[0044] FIGURE 6 illustrates an example UE, according to certain embodiments;

[0045] FIGURE 7 illustrates an example network node, according to certain embodiments; and FIGURE 8 illustrates a virtualization environment in which functions implemented by some embodiments may be virtualized, according to certain embodiments.

[0046] DETAILED DESCRIPTION

[0047] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0048] Certain embodiments introduce means for a first (source) RAN node such as, for example, a gNB-CU, to prepare a mobility action with a target RAN node, to evaluate whether the execution of such mobility action is beneficial, and to trigger towards the UE the activation of the mobility execution conditions. The latter may be achieved either via direct communication with the UE or via communication with a second RAN node such as, for example, from a gNB-CU to a gNB-DU, to indicate activation of execution conditions for a mobility procedure at a UE.

[0049] The advantage of enabling the source RAN node to trigger the activation of the execution conditions of the prepared mobility action at a specific point in time is that the source RAN node may, after preparation of the mobility procedure and before triggering activation of the execution conditions, monitor through the neighbor nodes, such as the target RAN nodes, what will be the neighbor nodes performance(s) (considering measured and / or predicted performances / metrics) assuming that the mobility action is taken. By means of that, the source RAN node may understand whether and when the execution of the mobility action is advantageous and, in function of that, to trigger activation of the execution conditions at the UE.

[0050] In this disclosure, NR is used as a radio access technology of reference. However, this is only an example taken for simplicity and it should not be limiting. The methods herein described apply to any radio access technology and conditional mobility procedures, where the conditional mobility procedures (such as Conditional Handover or Conditional LTM) comprise a preparation step and / or an execution step.

[0051] For a gNB-CU to gain and exercise control over the activation of execution conditions towards a UE for a mobility procedure such as, for example, a CHO, after the mobility action has been prepared with the target node, the following means are needed:

[0052] • A gNB-CU must be able to prepare a mobility action such as, for example, via Handover Preparation procedure over the Xn interface, with a target network node.

[0053] • A gNB-CU must be able to configure UE(s) for CHO with execution pending network indication to the UE(s) that execution conditions are active, and / or for CHO with execution condition evaluation pending network indication to the UE(s) that the execution conditions are active. Optionally, the gNB-CU may instruct a gNB-DU that the transmission of the said network indication to the UE(s) is pending triggering from the gNB-CU.

[0054] • A gNB-CU must be able to instruct a gNB-DU to deliver / transmit the said network indication / command to the UE(s), or to deliver / transmit the said network indication / command to the UE(s) by itself, e.g., via RRC signaling.

[0055] The gNB-CU is a more central node compared to the gNB-DU, i.e., with a wider range of information and a larger observability of the local network than the gNB-DU. According to certain embodiments, if the gNB-CU needs / wants to control the activation of conditional handover execution conditions at a UE, or the gNB-CU needs / wants to trigger the UE for the execution of a handover procedure, it is able to do it.

[0056] According to certain embodiments, a gNB-CU is enabled to control activation of CHO execution conditions at the UE, e.g., for a NES CHO. Specifically, a gNB-CU can send, to a gNB-DU, an indication / command to activate CHO execution conditions at the UE. Alternatively, a gNB-CU can send, directly to the UE, an indication to activate CHO execution conditions. Moreover, a gNB-CU can send to a gNB-DU an indication that activation of CHO execution conditions at the UE is pending until, or is subject to, indication from the gNB-CU.

[0057] CHO Preparation with gNB-CU Triggered CHO Execution Condition(s) Activation

[0058] According to certain embodiments, the legacy solution for CHO preparation is enhanced by enabling the gNB-CU of the source RAN node to indicate to the gNB-DU of the source RAN node that the gNB-CU controls the CHO execution condition activation towards the UE. For example, in a particular embodiment, the gNB-CU indicates to the gNB-DU that a CHO, which has been prepared or is being prepared towards a target node and is configured at one or more UEs, is subject to a later trigger / indication that will be provided by the gNB- CU, where such trigger activates at the UE the execution of the CHO (or the evaluation / activation of the CHO execution conditions). In a particular embodiment, the indication towards the gNB-DU for which the gNB-CU controls the CHO execution condition activation is generic. For example, the indication may be a per-gNB-DU indication and, thus, not point to a specific UE or to a specific group of UEs. Alternatively, in a particular embodiment, the indication is per-UE served by the gNB-DU, or for a group of UEs served by the gNB-DU (e.g., for all UEs in a particular cell) , or for target cell for which a set of UEs have been configured. More details on these embodiments are described below.

[0059] In another particular embodiment, the legacy solution for CHO preparation is enhanced by enabling the gNB-DU of the source RAN node to indicate to one or more UEs that CHO execution (or the evaluation of the CHO execution condition(s)) is activated.

[0060] In a particular embodiment, during CHO preparation, a UE receives from the network an indication (or is instructed accordingly) that CHO execution (or the evaluation of the CHO execution condition(s)) is pending, or subject to, later network indication.

[0061] In a particular embodiment, the source gNB-CU indicates to the source gNB-DU that a certain UE is configured (or is being configured or will be configured) for CHO with execution pending network indication before or during the CHO preparation. For example, in an enhanced version of the UE CONTEXT MODIFICATION REQUEST message, the gNB-CU may indicate that a certain UE is configured (or is being configured or will be configured) for CHO with execution pending network indication. Optionally, in a particular purpose, the gNB-CU indicates that the CHO is prepared for a certain purpose such as, for example, AI / ML based Network Energy Saving. In another particular embodiment, the gNB-CU indicates that the UE is associated with a certain group of UEs.

[0062] In the case of NES CHO, where CHO execution (or CHO execution condition activation) is triggered by a specific Downlink Control Information (DCI) with Cyclic Redundancy Check (CRC) scrambled with a specific Radio Network Temporary Identifier (RNTI), and the UE is allocated (configured with, or provided) a specific RNTI value to only receive / decode the Downlink Control Information (DCI) if the DCFs Cyclic Redundancy Check (CRC) is scrambled with the specific RNTI value, the gNB-DU can decide to configure a different RNTI value for the UE to monitor taking into account the notification from the gNB- CU that the UE is (will be) configured with a CHO with pending conditions activation. The configured RNTI value is part of the CellGroupConfig IE. In a particular embodiment, the gNB-DU puts the modified CellGroupConfig IE in the corresponding UE CONTEXT MODIFICATION RESPONSE message such that the UE will be configured accordingly upon RRC reconfiguration for NES CHO. The gNB-CU may read the configured RNTI value from the CellGroupConfig IE or the gNB-DU may explicitly indicate the configured RNTI value to the gNB-CU. In a particular embodiment, each UE is configured with a different RNTI value. In another particular embodiment, all UEs configured for NES CHO, or any CHO with execution pending network indication, toward a certain (same) target cell (ID) are configured with a certain (same) RNTI value. Configuring a different RNTI value for UEs that are configured for NES CHO for the purpose of AI / ML based Network Energy Saving has the advantage that transmission of a DCI with CRC scrambled with that different RNTI value only activates the CHO execution conditions for those UEs, not all UEs that are configured for NES CHO. gNB-CU-triggered Execution or Activation of Execution Conditions of CHO

[0063] In a particular embodiment, the gNB-CU of the source RAN node that initiated the CHO preparation towards the target RAN node for one or more UEs determines that the execution of such CHO mobility can / should be triggered for one or more UEs in the set of UEs for which the mobility actions have been prepared. The source gNB-CU sends a message to the source gNB-DU serving the one or more UEs, indicating that CHO execution can proceed. As a consequence, the source gNB-DU signals to the one or more UEs that execution conditions are activated.

[0064] In another particular embodiment, if one or more UEs prepared for CHO have received from the gNB-CU during the CHO preparation an indication that the CHO execution conditions are disabled / (b)locked / not enabled / not allowed, and after receiving from the gNB-CU an indication to allow / enable the CHO for one or more UEs, the gNB-DU sends to one or more of such UEs an indication / command such as, for example, via DCI, to enable / unlock / allow CHO execution.

[0065] In another particular embodiment, the indication that CHO execution (or evaluation of CHO execution conditions) is allowed / enabled / unlocked is only for UEs currently served by certain source cell(s). For example, in a particular embodiment, the gNB-CU signals to the gNB-DU that certain specific UEs should be signaled with an indication / command to activate execution conditions only if such UEs are in specific cells indicated by the gNB-CU, (e.g., by means of their Cell Group Identifiers (CGIs)). In a particular embodiment, the gNB-CU provides, to the gNB-DU, conditions according to which the gNB-DU should trigger the signalling towards the UE. These conditions may either be in retrospect or irrespective of the gNB-CU transmitting a signal that evaluation of CHO execution is enabled / unlocked / allowed to the gNB-DU. Such conditions may include one or more of the following:

[0066] • A threshold for an energy consumption metric (or energy cost), where the metric can relate to measurements and / or to predictions, where such metric can be at cell level or at node level or an energy consumption metric (or energy cost) internal to the gNB-DU and that it indicates the threshold at / above / below which the energy consumption metric needs to be for the triggering to take place.

[0067] • Two thresholds for an energy consumption metric (or energy cost), where the metric can relate to measurements and / or to predictions, where such metric can be at cell level or at node level or an energy consumption metric (or energy cost) internal to the gNB-DU and that it indicates the thresholds within which or outside which (as upper bound and lower bound), the energy consumption metric needs to be for the triggering to take place.

[0068] • The cell load status; namely a threshold at or above or below which the cell load needs to be for the triggering to take place.

[0069] • The activation time for the triggering towards the UE.

[0070] • A maximum activation time to be considered for the triggering towards the UE.

[0071] • A suggested activation time to be considered for the triggering towards the UE.

[0072] In a particular embodiment, the source gNB-CU determines that it is appropriate to cancel one or more CHO(s) whose activation of CHO execution conditions is(are) pending gNB-CU decision. In this case, the gNB-CU sends an indication to cancel the CHO(s) with pending conditions towards the gNB-DU (e.g., in a UE CONTEXT MODIFICATION REQUEST message). In the above embodiment the signalling towards the UE may be of different types, for example:

[0073] • A Medium Access Control (MAC) Control Element (CE) signal

[0074] • A specific DCI signal

[0075] In a particular embodiment, gNB-CU triggers UE to start the CHO execution by means of RRC signalling (e.g., light weight RRC signaling). In this scenario where the triggering happens at the RRC-level, the UE may be configured with one or more CHO configurations for which execution conditions have been disabled / locked / not enabled / not allowed. During this time, the source receives information from neighbour nodes that enable the source RAN to evaluate if the CHO towards a certain node is beneficial or not. The gNB-CU may decide to activate / unlock / allow / enable execution conditions of one or more of such CHO configurations depending on the ascertained network state.

[0076] In a particular embodiment, the source RAN node prepares the CHO towards a target RAN node, but it does not configure the UE with the CHO configuration. When the source gNB-CU determines that it is appropriate to enable the activation of the CHO execution conditions, the source gNB-CU signals, to the UE, the CHO configuration including the execution conditions. Such configuration is not subject to further triggering of condition activations, but it implicitly instructs the UE to evaluate execution conditions and, if they are fulfilled, execute the CHO. Note that, in this embodiment, the source RAN node places the configuration towards the UE on hold after having completed the CHO preparation with the target RAN node. During this time, the source receives information from neighbour nodes that enable the source RAN to evaluate if the CHO is beneficial or not. Such information may consist in predictions of the Energy Cost from neighbour nodes taking the prepared CHO into account.

[0077] In a particular embodiment, the gNB-CU implicitly triggers the execution of the CHO by signaling to the gNB-DU the execution of another action. For example, if the gNB-CU signals to the gNB-DU the deactivation of one or more cells (e.g., using the Cells to be Deactivated List IE in the F1AP GNB-CU CONFIGURATION UPDATE message), the gNB- DU understands that it should trigger the offloading of all the UEs served by the one or more cells to be deactivated. That implicitly means that the gNB-DU needs to signal to all the UEs served in the cell to be deactivated a trigger for CHO condition activation, and UEs that still remains attached to the cell beyond a time after which the trigger was CHO activation was transmitted may be handled separately before the cell is deactivated.

[0078] When the gNB-CU indicates to the gNB-DU that CHO execution (or CHO execution condition evaluation) can start, the gNB-CU may indicate to the gNB-DU one or more RNTI values, where the RNTI values may be assigned to specific UEs or to groups of UEs. The gNB- DU may then send, for each RNTI value, at least one DCI with CRC scrambled by the respective RNTI value, so that only the subset of UEs configured with, and monitoring, the RNTI value(s) receive / decode the DCI, i.e., only the subset of UEs can proceed with CHO execution condition evaluation (and CHO execution). Alternatively, the gNB-CU may indicate to the gNB-DU one or more target cells (target cell IDs) such as, for example, in a case where the gNB-DU has allocated / configured a separate RNTI value for each set of UEs configured for a certain target cell (ID). In that case, the network has more control over which UEs to activate the CHO execution conditions for at a certain time.

[0079] Network Indications for CHO Execution Activation

[0080] In a particular embodiment, the source RAN node initiating the CHO preparation (or a function of the source RAN node (e.g., the gNB-CU)) determines that CHO execution is subject to network activation. The criteria based on which this determination is done can be called network trigger(s) for activation of CHO execution.

[0081] An example of network trigger(s) for activation of CHO execution is that source RAN node wants to perform HO only if a predicted energy cost received from a potential target RAN node indicates that after the HO is executed the overall energy cost (of the source and target RAN nodes, or just the energy cost at the target RAN node, or just the energy cost at the source RAN node) will be within certain level(s). The source RAN node indicates that CHO execution activation is subject to network trigger, as described in the previous embodiments.

[0082] Later, when the network (e.g., the gNB-CU of the source RAN node) determines that some conditions are satisfied and that CHO execution can start, the network sends network indications / commands for CHO execution activation. These are signaled from gNB-CU to gNB-DU and / or from gNB-CU / gNB-DU to the UE to indicate that CHO execution can proceed for specific UEs that are allowed to start CHO execution.

[0083] Network indications for CHO execution activation can be one or more or a combination of the following:

[0084] • indication that CHO execution is pending network initiation,

[0085] • indication that a pending CHO execution is allowed / can start,

[0086] • indication that a pending CHO execution is not allowed / cannot start,

[0087] • a reason (e.g., a cause value) for CHO execution,

[0088] • a reason (e.g., a cause value) associated to the CHO for which CHO execution is allowed (or not allowed), e.g., for a UE, or for a group of UEs, for all UEs,

[0089] • indication of whether CHO execution for a UE is allowed / can start or is not allowed / cannot start,

[0090] • indication of whether CHO execution for a group of UE is allowed / can start or is not allowed / cannot start,

[0091] • indication of a UE identity, or a list of UE identities, identifying the UE (or the set of UEs) which will be targeted for network-controlled CHO execution, • an indication of a RNTI, and one or a list of RNTIs can be sent by the gNB-CU to that gNB-DU to indicate which UEs which will be targeted for network controlled CHO execution. The UEs corresponding to the list of RNTIs can be instructed to monitor a DCI format 2_9 with NES event indication bit setindication of other identifiers that may be used to select / deselect a set of UEs that will be targeted for network-controlled CHO execution, e.g., the target cells for which a group of UEs have been configured for

[0092] Network indications for CHO execution activation can be sent, for example: from a gNB-CU to one or more of the controlled gNB-DU; from a gNB-DU to a UE; from a gNB-DU to a group of UEs; from a gNB-DU to all UEs.

[0093] Network indications for CHO execution activation can be sent, for example, per UE granularity or per group of UE granularity.

[0094] Network indications for CHO execution activation can be sent, for example, in a UE- associated signaling message or in a non-UE-associated signaling message.

[0095] Note that combinations of the above are possible. For instance:

[0096] • In a particular embodiment, a gNB-CU sends to a gNB-DU a network indication for CHO execution activation in a UE-associated signaling message. Thus, the content of the signaling applies to one UE only.

[0097] • In a particular embodiment, a gNB-CU sends to a gNB-DU one network indication for CHO execution activation in a non-UE-associated signaling message. In a further particular embodiment, the non-UE associated message contains a list of UE(s), so that the network indication for CHO execution activation applies to all the UEs in the list of UE.

[0098] • In a particular embodiment, a gNB-CU sends, to a gNB-DU, a non-UE- associated signaling message containing a list of UE(s) where one network indication for CHO execution activation applies to a first set of UEs in the list of UEs, and another network indication for CHO execution activation applies to another (disjoint) set of UEs in the list of UEs.

[0099] • In a particular embodiment, a gNB-DU sends one message / indication / command per UE. The message / indications / command includes network indication for CHO execution activation which will be applicable only to that UE.

[0100] • In a particular embodiment, a gNB-DU sends one message / indication / command per group of UE. The message / indications / command comprising network indication for CHO execution activation which will be applicable to a group of UEs.

[0101] In a particular embodiment, the network indication for CHO execution activation are sent to a UE (or a group of UEs, or a list of UEs, or to all UEs in a cell) via a MAC CE.

[0102] In a particular embodiment, the network indication for CHO execution activation are sent to a UE (or a group of UEs, or a list of UEs, or to all UEs in a cell) via DCI.

[0103] In a particular embodiment, the network indication for CHO execution activation is sent to a UE (or a group of UEs, or a list of UEs, or to all UEs in a cell) via RRC signaling during CHO preparation (or after CHO preparation). In a further particular embodiment, the source RAN node for CHO includes in an RRC message sent to the UE (e.g., an RRCReconfiguration message comprising the CHO configuration), a priority associated to a certain candidate cell. In another embodiment, a candidate target RAN node for CHO includes in an RRC message sent to the UE (e.g., an RRCReconfiguration message comprising the configuration of CHO candidate cells included in the CHO configuration) a priority for associated to a certain candidate cell.

[0104] FIGURE 3 illustrates an example method 100 by a gNB-CU for configuring a conditional mobility procedure, according to certain embodiments. As illustrated, the method 100 includes a step 102 of triggering activation of at least one execution condition for the conditional mobility procedure for at least one UE.

[0105] In a particular embodiment, triggering activation of the at least one execution condition includes transmitting, to a gNB-DU, a first indication to activate the at least one execution condition for the conditional mobility procedure.

[0106] In a particular embodiment, triggering activation of the at least one execution condition includes transmitting, to the at least one UE, a second indication to activate the at least one execution condition for the conditional mobility procedure.

[0107] In a particular embodiment, the gNB-CU transmits a third indication that activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is pending until the first indication or the second indication is received from the gNB-CU.

[0108] In a further particular embodiment, the third indication is transmitted to a gNB-DU, and the third indication indicates at least one of: the activation of the at least one execution condition for the conditional mobility procedure is pending for a single UE; the activation of the at least one execution condition for the conditional mobility procedure is pending for a group of UEs; the activation of the at least one execution condition for the conditional mobility procedure is pending for one or more target cells or one or more source cells; and the activation of the at least one execution condition for the conditional mobility procedure is pending for any UEs that are served by the gNB-DU.

[0109] In a particular embodiment, at least one of the first indication, the second indication, and the third indication identifies a RNTI associated with the at least one UE.

[0110] In a particular embodiment, at least one of: the activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is for a single UE; the activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is for a group of UEs; the activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is for one or more target cells or one or more source cells; and the activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is for any UEs that are served by a gNB- DU.

[0111] In a particular embodiment, the gNB-CU determines that it is beneficial to execute the conditional mobility procedure for the at least one UE. The gNB-CU triggers the activation of the at least one execution condition for the conditional mobility procedure for the at least one UE based on determining that it is beneficial to execute the conditional mobility procedure for the at least one UE.

[0112] In a particular embodiment, the gNB-CU receives assistance information, and the gNB- CU determines that it is beneficial to execute the conditional mobility procedure for the at least one UE based on the assistance information.

[0113] In a further particular embodiment, the assistance information is received after receiving one or more HANDOVER REQUEST ACKNOWLEDGE messages from one or more neighboring network nodes.

[0114] In a particular embodiment, the conditional mobility procedure comprises at least one of: a NES conditional handover; a Conditional Handover; or a Conditional LTM.

[0115] In a particular embodiment, the gNB-CU transmits, to a gNB-DU, an indication that a particular UE is or will be configured for the conditional mobility procedure with execution pending network indication before or during preparation for the conditional mobility procedure.

[0116] In a particular embodiment, triggering activation of the at least one execution condition for the conditional mobility procedure for the at least one UE includes completing preparation for the conditional mobility procedure with the target network node and determining that the conditional mobility procedure is beneficial to the network. Based on determining that the conditional mobility procedure is beneficial to the network, the gNB-CU transmits a handover command and / or the at least one execution condition.

[0117] In a particular embodiment, the gNB-CU signals, to the gNB-DU, an indication of deactivation of one or more cells. The gNB-DU is configured to signal, to the at least one UE served in the one or more cells to be deactivated, a trigger for activation of the at least one execution condition.

[0118] In a particular embodiment, the gNB-CU transmits at least one network indication for triggering activation of the at least one execution condition. The at least one network indication comprises at least one of: an indication that execution of the conditional mobility procedure is pending network initiation, an indication that a pending execution of the conditional mobility procedure is allowed and / or can start, an indication that a pending execution of the conditional mobility procedure is not allowed and / or cannot start, a reason or a cause value for execution of the conditional mobility procedure, and an indication of a UE identity or a list of UE identities that will be targeted for execution of the conditional mobility procedure.

[0119] In a particular embodiment, the gNB-CU transmits, to a gNB-DU, at least one trigger condition for triggering signaling towards the at least one UE.

[0120] In a particular embodiment, the at least one trigger condition for triggering signaling towards the at least one UE comprise at least one of: at least one threshold for an energy consumption metric and / or energy cost, at least one threshold associated with a cell load, an activation time for triggering the conditional mobility procedure for the at least one UE, a maximum activation time for the triggering the conditional mobility procedure for the at least one UE, and a suggested activation time for the triggering the conditional mobility procedure for the at least one UE.

[0121] FIGURE 4 illustrates an example method 200 by a gNB-DU for configuring a conditional mobility procedure, according to certain embodiments. As illustrated the method begins at step 202 when the gNB-DU receives, from a gNB-CU, a first indication to activate at least one execution condition for the conditional mobility procedure for at least one UE. Additionally or alternatively, the gNB-DU receives, at step 204, from the gNB-CU, a third indication that activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is pending until the first indication is received from the gNB- CU or until a second indication from the gNB-CU is received by the at least one UE.

[0122] In a particular embodiment, the gNB-DU transmits, to the at least one UE, a fourth indication to activate the at least one execution condition for the conditional mobility procedure. In a particular embodiment, at least one of the first indication and the third indication is for at least one of: a single UE, a group of UEs, one or more target cells or one or more source cells, and any UEs that are served by the gNB-DU.

[0123] In a particular embodiment, the activation of the at least one execution condition for the conditional mobility procedure is for at least one of: a single UE, a group of UEs, one or more target cells or one or more source cells, and any UEs that are served by the gNB-DU.

[0124] In a particular embodiment, at least one of the first indication, the second indication, the third indication, and the fourth indication identifies a RNTI associated with the at least one UE.

[0125] In a particular embodiment, at least one of the first indication and the third indication indicates that the conditional mobility procedure for the at least one UE is beneficial for the network.

[0126] In a particular embodiment, the conditional mobility procedure comprises at least one of: a NES conditional handover; a Conditional Handover; or a Conditional LTM.

[0127] In a particular embodiment, the gNB-DU receives, from the gNB-CU, an indication to cancel the conditional mobility procedure for the at least one UE.

[0128] In a particular embodiment, the gNB-DU receives, from the gNB-CU, an indication of deactivation of one or more cells and signaling, to the at least one UE served in the one or more cells to be deactivated, a trigger for activation of the at least one execution condition.

[0129] In a particular embodiment, the gNB-DU receives, from the gNB-CU, at least one network indication for triggering activation of the at least one execution condition. The at least one network indication comprises at least one of: an indication that execution of the conditional mobility procedure is pending network initiation, an indication that a pending execution of the conditional mobility procedure is allowed and / or can start, an indication that a pending execution of the conditional mobility procedure is not allowed and / or cannot start, a reason or a cause value for execution of the conditional mobility procedure, and an indication of a UE identity or a list of UE identities that will be targeted for execution of the conditional mobility procedure.

[0130] In a particular embodiment, the gNB-DU receives, from the gNB-CU, at least one trigger condition for triggering signaling towards the at least one UE.

[0131] In a further particular embodiment, the at least one trigger condition for triggering signaling towards the at least one UE comprise at least one of: at least one threshold for an energy consumption metric and / or energy cost, at least one threshold associated with a cell load, an activation time for triggering the conditional mobility procedure for the at least one UE, a maximum activation time for the triggering of the conditional mobility procedure for the at least one UE, and a suggested activation time for the triggering of the conditional mobility procedure for the at least one UE.

[0132] In a particular embodiment, the gNB-DU receives, from the gNB-CU, an indication that a particular UE is or will be configured for the conditional mobility procedure with execution pending network indication before or during preparation for the conditional mobility procedure.

[0133] FIGURE 5 shows an example of a communication system 300 in accordance with some embodiments. In the example, the communication system 300 includes a telecommunication network 302 that includes an access network 304, such as a radio access network (RAN), and a core network 306, which includes one or more core network nodes 308. The access network 304 includes one or more access network nodes, such as network nodes 310a and 310b (one or more of which may be generally referred to as network nodes 310), or any other similar 3rdGeneration Partnership Project (3GPP) access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 302 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 302 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 302, including one or more network nodes 310 and / or core network nodes 308.

[0134] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O- CU-CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an 0-2 interface defined by the 0-RAN Alliance or comparable technologies. The network nodes 310 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 312a, 312b, 312c, and 312d (one or more of which may be generally referred to as UEs 312) to the core network 306 over one or more wireless connections.

[0135] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 300 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 300 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0136] The UEs 312 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 310 and other communication devices. Similarly, the network nodes 310 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 312 and / or with other network nodes or equipment in the telecommunication network 302 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 302.

[0137] In the depicted example, the core network 306 connects the network nodes 310 to one or more host computing systems, such as host 316. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 306 includes one more core network nodes (e.g., core network node 308) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 308. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0138] The host 316 may be under the ownership or control of a service provider other than an operator or provider of the access network 304 and / or the telecommunication network 302. The host 316 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0139] As a whole, the communication system 300 of FIGURE 5 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0140] In some examples, the telecommunication network 302 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 302 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 302. For example, the telecommunications network 302 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC)ZMassive loT services to yet further UEs.

[0141] In some examples, the UEs 312 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 304 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 304. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0142] In the example, the hub 314 communicates with the access network 304 to facilitate indirect communication between one or more UEs (e.g., UE 312c and / or 312d) and network nodes (e.g., network node 310b). In some examples, the hub 314 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 314 may be a broadband router enabling access to the core network 306 for the UEs. As another example, the hub 314 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 310, or by executable code, script, process, or other instructions in the hub 314. As another example, the hub 314 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 314 may be a content source. For example, for a UE that is a VR device, display, loudspeaker, or other media delivery device, the hub 314 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 314 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 314 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0143] The hub 314 may have a constant / persistent or intermittent connection to the network node 310b. The hub 314 may also allow for a different communication scheme and / or schedule between the hub 314 and UEs (e.g., UE 312c and / or 312d), and between the hub 314 and the core network 306. In other examples, the hub 314 is connected to the core network 306 and / or one or more UEs via a wired connection. Moreover, the hub 314 may be configured to connect to an M2M service provider over the access network 304 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 310 while still connected via the hub 314 via a wired or wireless connection. In some embodiments, the hub 314 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 310b. In other embodiments, the hub 314 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 310b, but which is additionally capable of operating as a communication start and / or end point for certain data channels. FIGURE 6 shows a UE 400 in accordance with some embodiments. The UE 400 presents additional details of some embodiments of the UE 312 of Figure 1. As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage / playback device, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), an Augmented Reality (AR) or Virtual Reality (VR) device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0144] A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle- to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0145] The UE 400 includes processing circuitry 402 that is operatively coupled via a bus 404 to an input / output interface 406, a power source 408, a memory 410, a communication interface 412, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in FIGURE 6. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0146] The processing circuitry 402 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 410. The processing circuitry 402 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 402 may include multiple central processing units (CPUs).

[0147] In the example, the input / output interface 406 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 400. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0148] In some embodiments, the power source 408 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 408 may further include power circuitry for delivering power from the power source 408 itself, and / or an external power source, to the various parts of the UE 400 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 408. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 408 to make the power suitable for the respective components of the UE 400 to which power is supplied. he memory 410 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 410 includes one or more application programs 414, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 416. The memory 410 may store, for use by the UE 400, any of a variety of various operating systems or combinations of operating systems.

[0149] The memory 410 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 410 may allow the UE 400 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 410, which may be or comprise a device-readable storage medium.

[0150] The processing circuitry 402 may be configured to communicate with an access network or other network using the communication interface 412. The communication interface 412 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 422. The communication interface 412 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 418 and / or a receiver 420 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 418 and receiver 420 may be coupled to one or more antennas (e.g., antenna 422) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0151] In the illustrated embodiment, communication functions of the communication interface 412 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / intemet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0152] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 412, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected, an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0153] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0154] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE

[0155] 400 shown in FIGURE 6.

[0156] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0157] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0158] FIGURE 7 shows a network node 500 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NRNodeBs (gNBs)), O-RAN nodes or components of an O-RAN node (e g., O-RU, O-DU, O-CU).

[0159] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0160] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0161] The network node 500 includes a processing circuitry 502, a memory 504, a communication interface 506, and a power source 508. The network node 500 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 500 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 500 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 504 for different RATs) and some components may be reused (e.g., a same antenna 510 may be shared by different RATs). The network node 500 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 500, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 500.

[0162] The processing circuitry 502 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 500 components, such as the memory 504, to provide network node 500 functionality. In some embodiments, the processing circuitry 502 includes a system on a chip (SOC). In some embodiments, the processing circuitry 502 includes one or more of radio frequency (RF) transceiver circuitry 512 and baseband processing circuitry 514. In some embodiments, the radio frequency (RF) transceiver circuitry 512 and the baseband processing circuitry 514 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 512 and baseband processing circuitry 514 may be on the same chip or set of chips, boards, or units.

[0163] The memory 504 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 502. The memory 504 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 502 and utilized by the network node 500. The memory 504 may be used to store any calculations made by the processing circuitry 502 and / or any data received via the communication interface 506. In some embodiments, the processing circuitry 502 and memory 504 is integrated.

[0164] The communication interface 506 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 506 comprises port(s) / terminal(s) 516 to send and receive data, for example to and from a network over a wired connection. The communication interface 506 also includes radio front-end circuitry 518 that may be coupled to, or in certain embodiments a part of, the antenna 510. Radio front-end circuitry 518 comprises filters 520 and amplifiers 522. The radio front-end circuitry 518 may be connected to an antenna 510 and processing circuitry 502. The radio front-end circuitry may be configured to condition signals communicated between antenna 510 and processing circuitry 502. The radio front-end circuitry 518 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 518 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 520 and / or amplifiers 522. The radio signal may then be transmitted via the antenna 510. Similarly, when receiving data, the antenna 510 may collect radio signals which are then converted into digital data by the radio front-end circuitry 518. The digital data may be passed to the processing circuitry 502. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0165] In certain alternative embodiments, the network node 500 does not include separate radio front-end circuitry 518, instead, the processing circuitry 502 includes radio front-end circuitry and is connected to the antenna 510. Similarly, in some embodiments, all or some of the RF transceiver circuitry 512 is part of the communication interface 506. In still other embodiments, the communication interface 506 includes one or more ports or terminals 516, the radio front-end circuitry 518, and the RF transceiver circuitry 512, as part of a radio unit (not shown), and the communication interface 506 communicates with the baseband processing circuitry 514, which is part of a digital unit (not shown).

[0166] The antenna 510 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 510 may be coupled to the radio front-end circuitry 518 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 510 is separate from the network node 500 and connectable to the network node 500 through an interface or port.

[0167] The antenna 510, communication interface 506, and / or the processing circuitry 502 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 510, the communication interface 506, and / or the processing circuitry 502 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0168] The power source 508 provides power to the various components of network node 500 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 508 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 500 with power for performing the functionality described herein. For example, the network node 500 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 508. As a further example, the power source 508 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0169] Embodiments of the network node 500 may include additional components beyond those shown in FIGURE 7 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 500 may include user interface equipment to allow input of information into the network node 500 and to allow output of information from the network node 500. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 500. In some embodiments providing a core network node, such as core network node 108 of FIG. 3, some components, such as the radio front-end circuitry 518 and the RF transceiver circuitry 512 may be omitted.

[0170] FIGURE 8 is a block diagram illustrating a virtualization environment 600 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 600 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 600 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface. Virtualization may facilitate distributed implementations of a network node, UE, core network node, or host.

[0171] Applications 602 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0172] Hardware 604 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 606 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 608a and 608b (one or more of which may be generally referred to as VMs 608), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 606 may present a virtual operating platform that appears like networking hardware to the VMs 608.

[0173] The VMs 608 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 606. Different embodiments of the instance of a virtual appliance 602 may be implemented on one or more of VMs 608, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0174] In the context of NFV, a VM 608 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 608, and that part of hardware 604 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 608 on top of the hardware 604 and corresponds to the application 602.

[0175] Hardware 604 may be implemented in a standalone network node with generic or specific components. Hardware 604 may implement some functions via virtualization. Alternatively, hardware 604 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 610, which, among others, oversees lifecycle management of applications 602. In some embodiments, hardware 604 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 612 which may alternatively be used for communication between hardware nodes and radio units. Although the computing devices described herein (e.g., UEs, network nodes) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0176] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer- readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally. EXAMPLE EMBODIMENTS

[0177] Group A Example Embodiments

[0178] Example Embodiment 1. A method performed by a user equipment for performing, or being configured for, a conditional mobility procedure, the method comprising: receiving during CHO preparation, from the network, an indication (or is instructed accordingly) that CHO execution (or the evaluation of the CHO execution condition(s)) is pending, or subject to, later network indication.

[0179] Example Embodiment 2. A method performed by a user equipment for performing, or being configured for, a conditional mobility procedure, the method comprising: receiving an indication to activate CHO execution conditions.

[0180] Example Embodiment 3. The method of Example Embodiment 1 further comprising embodiment 2.

[0181] Example Embodiment 4. The method of any of Example Embodiments 1 to 3, wherein either receiving is from at least one of: a gNB-DU; a gNB-CU.

[0182] Example Embodiment 5. The method of any of Example Embodiments, wherein the conditional mobility procedure comprises at least one of: NES conditional handover; Conditional Handover; or Conditional LTM; a preparation step; an execution step.

[0183] Example Embodiment 6. The method of any of Example Embodiment 1 to 5, wherein mobility procedure is used to coordinate the offloading of UEs (e.g., from a cell to be deactivated for energy savings reasons) to a number of neighboring gNBs, e.g., the gNB-CU could enable the execution of the NES CHO after receiving assistance information not available at the time of receiving the HANDOVER REQUEST ACKNOWLEDGE messages from the neighboring gNBs. The assistance information received by the gNB-CU may reveal that it is beneficial to execute the conditional handover because the overall performance of the nodes involved in the mobility action (source and target nodes) or the performance of a set of RAN nodes, e.g., a cluster, is optimized with respect to the case where the action is not executed. The performance of neighbouring gNBs can relate to measurements and / or predictions.

[0184] Group B Embodiments

[0185] Example Embodiment 7. A method performed by a first network node for performing / configuring a conditional mobility procedure, the method comprising:

[0186] Option 1 - transmitting to a second network node an indication to activate CHO execution conditions at the UE; or

[0187] Option 2 - transmitting to the UE an indication to activate CHO execution conditions; or Option 3 - transmitting to a second network node an indication that activation of CHO execution conditions at the UE is pending until, or is subject to, indication from the first network node.

[0188] Example Embodiment 8. The method of Example Embodiment 7, wherein the second network node is a gNB-DU.

[0189] Example Embodiment 9. The method of Example Embodiment 7 or 8, wherein the first network node is a gNB-CU.

[0190] Example Embodiment 10. The method of any of Example Embodiments 7 to 9, wherein the conditional mobility procedure comprises at least one of: NES conditional handover; Conditional Handover; or Conditional LTM; a preparation step; an execution step.

[0191] Example Embodiment 11. The method of Example Embodiment 10, wherein the gNB-DU indicates to the UE via at least one of: RRC signaling; DCI signaling; MAC CE signaling.

[0192] Example Embodiment 12. The method of Example Embodiments 10 or 11, wherein the NES CHO is used to coordinate the offloading of UEs (e.g., from a cell to be deactivated for energy savings reasons) to a number of neighboring gNBs, e.g., the gNB-CU could enable the execution of the NES CHO after receiving assistance information not available at the time of receiving the HANDOVER REQUEST ACKNOWLEDGE messages from the neighboring gNBs. The assistance information received by the gNB-CU may reveal that it is beneficial to execute the conditional handover because the overall performance of the nodes involved in the mobility action (source and target nodes) or the performance of a set of RAN nodes, e.g., a cluster, is optimized with respect to the case where the action is not executed. The performance of neighbouring gNBs can relate to measurements and / or predictions.

[0193] Example Embodiment 13. The method of any of Example Embodiments 7 to 12, under option 3, wherein the transmitting comprises the gNB-CU indicates to the gNB-DU that a CHO that has being prepared or is being prepared towards a target node and is configured at one or more UEs is subject to a later trigger / indication that will be provided by the gNB-CU, where such trigger activates at the UE the execution of the CHO (or the evaluation / activation of the CHO execution conditions).

[0194] Example Embodiment 14. The method of any of Example Embodiments 7 to 13, under option 3, wherein the indication towards the gNB-DU for which the gNB-CU controls the CHO execution condition activation can be generic, i.e., aper-gNB-DU indication (i.e., not pointing to a specific UE, or to a specific group of UEs), or it can be per-UE served by the gNB-DU, or it can be for a group of UEs served by the gNB-DU (e.g., for all UEs in a particular cell) , or it can be per target cell for which a set of UEs have been configured.

[0195] Example Embodiment 15. The method of any of Example Embodiments 7 to 14, wherein the source gNB-CU can indicate to the source gNB-DU that a certain UE is configured (or is being configured or will be configured) for CHO with execution pending network indication before or during the CHO preparation. For example, the gNB-CU can, in an enhanced version of the UE CONTEXT MODIFICATION REQUEST message, indicate that a certain UE is configured (or is being configured, or will be configured) for CHO with execution pending network indication. Optionally the gNB-CU can indicate that the CHO is prepared for a certain purpose, e.g., AI / ML based Network Energy Saving, and / or that the UE is associated with a certain group of UEs.

[0196] Example Embodiment 16. The method of any of Example Embodiments 7 to 15, wherein, in the case of NES CHO, where CHO execution (or CHO execution condition activation) is triggered by a specific Downlink Control Information (DCI) with Cyclic Redundancy Check (CRC) scrambled with a specific RNTI, and the UE is allocated (configured with, or provided) a specific Radio Network Temporary Identifier (RNTI) value to only receive / decode the DCI if the DCFs CRC is scrambled with the specific RNTI value, the gNB-DU can decide to configure a different RNTI value for the UE to monitor taking into account the notification from the gNB-CU that the UE is (will be) configured with a CHO with pending conditions activation (The configured RNTI value is part of the CellGroupConfig IE).

[0197] Example Embodiment 17. The method of Example Embodiment 16, wherein the gNB-DU can then put the modified CellGroupConfig IE in the corresponding UE CONTEXT MODIFICATION RESPONSE message such that the UE will be configured accordingly upon RRC reconfiguration for NES CHO.

[0198] Example Embodiment 18. The method of Example Embodiment 16 or 17, wherein the gNB-CU may read the configured RNTI value from the CellGroupConfig IE or the gNB-DU may explicitly indicate the configured RNTI value to the gNB-CU. In one case, each UE is configured with a different RNTI value. In another case, all UEs configured for NES CHO, or any CHO with execution pending network indication, toward a certain (same) target cell (ID) are configured with a certain (same) RNTI value.

[0199] Example Embodiment 19. The method of any of Example Embodiments 7 to 18, wherein the gNB-CU of the source RAN node that initiated the CHO preparation towards the target RAN node for one or more UEs, determines that the execution of such CHO mobility can / should be triggered for one or more UEs in the set of UEs for which the mobility actions have been prepared. Example Embodiment 20. The method of any of Example Embodiments 7 to 19, wherein the source gNB-CU sends a message to the source gNB-DU serving the one or more UEs, indicating that CHO execution can proceed. As a consequence, the source gNB-DU signals to the one or more UEs that execution conditions are activated.

[0200] Example Embodiment 21. The method of any of Example Embodiment 7 to 20, under option 1 or 3, wherein the indication that CHO execution (or evaluation of CHO execution conditions) is allowed / enabled / unlocked is only for UEs currently served by certain source cell(s). Namely, the gNB-CU signals to the gNB-DU that certain specific UEs should be signalled with an indication / command to activate execution conditions only if such UEs are in specific cells indicated by the gNB-CU, e.g. by means of their CGIs.

[0201] Example Embodiment 22. The method of any of Example Embodiment s 7 to 21, under option 3, wherein the gNB-CU configures to the gNB-DU conditions according to which the gNB-DU should trigger the signalling towards the UE. These conditions may either be in retrospect or irrespective of the gNB-CU transmitting a signal that evaluation of CHO execution is enabled / unlocked / allowed to the gNB-DU. Such conditions may include one or more of the following:

[0202] • A threshold for an energy consumption metric (or energy cost), where the metric can relate to measurements and / or to predictions, where such metric can be at cell level or at node level or an energy consumption metric (or energy cost) internal to the gNB-DU and that it indicates the threshold at / above / below which the energy consumption metric needs to be for the triggering to take place

[0203] • Two thresholds for an energy consumption metric (or energy cost), where the metric can relate to measurements and / or to predictions, where such metric can be at cell level or at node level or an energy consumption metric (or energy cost) internal to the gNB-DU and that it indicates the thresholds within which or outside which (as upper bound and lower bound), the energy consumption metric needs to be for the triggering to take place

[0204] • The cell load status; namely a threshold at or above or below which the cell load needs to be for the triggering to take place

[0205] • The activation time for the triggering towards the UE.

[0206] • A maximum activation time to be considered for the triggering towards the UE

[0207] • A suggested activation time to be considered for the triggering towards the UE Example Embodiment 23. The method of any of embodiments 7 to 22, wherein the source gNB-CU determines that it is appropriate to cancel one or more CHO(s) whose activation of CHO execution conditions is(are) pending gNB-CU decision. The gNB-CU in this case sends an indication to cancel the CHO(s) with pending conditions towards the gNB- DU (e.g., in a UE CONTEXT MODIFICATION REQUEST message). In the above embodiment the signalling towards the UE may be of different types, for example:

[0208] • A Medium Access Control (MAC) Control Element (CE) signal; or

[0209] • A specific DCI signal.

[0210] Example Embodiment 24. The method of any of Example Embodiments 7 to 23, under option 2, wherein the gNB-CU triggers UE to start the CHO execution by means of RRC signalling (e.g. light weight RRC signaling). In this scenario where the triggering happens at the RRC-level, the UE may be configured with one or more CHO configurations for which execution conditions have been disabled / locked / not enabled / not allowed. During this time, the source receives information from neighbour nodes that enable the source RAN to evaluate if the CHO towards a certain node is beneficial or not. The gNB-CU may decide to activate / unlock / allow / enable execution conditions of one or more of such CHO configurations depending on the ascertained network state.

[0211] Example Embodiment 25. The method of any of Example Embodiments 7 to 24, wherein the source RAN node prepares the CHO towards a target RAN node, but it does not configure the UE with the CHO configuration. When the source gNB-CU determines that it is appropriate to enable the activation of the CHO execution conditions, the source gNB-CU signals to the UE the CHO configuration including the execution conditions. Such configuration is not subject to further triggering of condition activations, but it implicitly instructs the UE to evaluate execution conditions and, if they are fulfilled, execute the CHO. Note that in this embodiment the source RAN places the configuration towards the UE on hold after having completed the CHO preparation with the target RAN node. During this time, the source receives information from neighbour nodes that enable the source RAN to evaluate if the CHO is beneficial or not. Such information may comprise predictions of the Energy Cost from neighbour nodes taking the prepared CHO into account.

[0212] Example Embodiment 26. The method of any of Example Embodiments 7 to 25, wherein the gNB-CU implicitly triggers the execution of the CHO by signaling to the gNB- DU the execution of another action. For example, if the gNB-CU signals to the gNB-DU the deactivation of one or more cells (e.g., using the Cells to be Deactivated List IE in the F1AP GNB-CU CONFIGURATION UPDATE message), the gNB-DU understands that it should trigger the offloading of all the UEs served by the one or more cells to be deactivated. That can mean that the gNB-DU needs to signal to all the UEs served in the Cell to be deactivated a trigger for CHO condition activation, and UEs that still remains attached to the cell beyond a time after which the trigger was CHO activation was transmitted may be handled separately before the cell is deactivated.

[0213] Example Embodiment 27. The method of any of Example Embodiments 7 to 26, under option 3, wherein when the gNB-CU indicates to the gNB-DU that CHO execution (or CHO execution condition evaluation) can start, the gNB-CU may indicate to the gNB-DU one or more RNTI values, where the RNTI values may be assigned to specific UEs or to groups of UEs. The gNB-DU may then send, for each RNTI value, at least one DCI with CRC scrambled by the respective RNTI value, so that only the subset of UEs configured with, and monitoring, the RNTI value(s) receive / decode the DCI, i.e., only the subset of UEs can proceed with CHO execution condition evaluation (and CHO execution). Alternatively, the gNB-CU may indicate to the gNB-DU one or more target cells (target cell IDs), e.g., in a case where the gNB-DU has allocated / configured a separate RNTI value for each set of UEs configured for a certain target cell (ID). In that case, the network has more control over which UEs to activate the CHO execution conditions for at a certain time.

[0214] Example Embodiment 28. The method of any of embodiments 7 to 27, wherein the source RAN node initiating the CHO preparation, or a function of the source RAN node (e.g., the gNB-CU) determines that CHO execution is subject to network activation. The criteria based on which this determination is done can be called network trigger(s) for activation of CHO execution.

[0215] Example Embodiment 29. The method of Example Embodiment 28, wherein an example of network trigger(s) for activation of CHO execution is that source RAN node wants to perform HO only if a predicted energy cost received by a potential target RAN node indicates that after the HO is executed the overall energy cost (of the source and target RAN node, or just the energy cost at the target RAN node, or just the energy cost at the source RAN node, will be within certain level(s)). The source RAN node indicates that CHO execution activation is subject to network trigger, as described in the previous embodiments.

[0216] Example Embodiment 30. The method of Example Embodiment 29, wherein later, when the network (e.g., the gNB-CU of the source RAN node) determines that some conditions are satisfied and that CHO execution can start, the network sends network indications / commands for CHO execution activation. These are signaled e.g., from gNB-CU to gNB-DU and / or from gNB-CU / gNB-DU to the UE to indicate that CHO execution can proceed for specific UEs that are allowed to start CHO execution.

[0217] Example Embodiment 31. The method of any of Example Embodiments 7 to 30, wherein network indications for CHO execution activation can be one or more or a combination of the following:

[0218] • indication that CHO execution is pending network initiation

[0219] • indication that a pending CHO execution is allowed / can start

[0220] • indication that a pending CHO execution is not allowed / cannot start

[0221] • a reason (e.g., a cause value) for CHO execution

[0222] • a reason (e.g., a cause value) associated to the CHO for which CHO execution is allowed (or not allowed), e.g., for a UE, or for a group of UEs, for all UEs

[0223] • indication of whether CHO execution for a UE is allowed / can start or is not allowed / cannot start

[0224] • indication of whether CHO execution for a group of UE is allowed / can start or is not allowed / cannot start

[0225] • indication of a UE identity, or a list of UE identities, identifying the UE (or the set of UEs) which will be targeted for network-controlled CHO execution.

[0226] • For example the UE identity can be a Radio Network Temporary Identifier, RNTI, and one or a list of RNTIs can be sent by the gNB-CU to that gNB-DU to indicate which UEs which will be targeted for network controlled CHO execution. The UEs corresponding to the list of RNTIs can be instructed to monitor a DCI format 2_9 with NES event indication bit setindication of other identifiers that may be used to select / deselect a set of UEs that will be targeted for network-controlled CHO execution, e.g., the target cells for which a group of UEs have been configured for.

[0227] Example Embodiment 32. The method of any of Example Embodiments 7 to 31, wherein network indications for CHO execution activation can be sent, e.g.: from a gNB-CU to one or more of the controlled gNB-DU; from a gNB-DU to a UE; from a gNB-DU to a group of UEs; from a gNB-DU to all UEs.

[0228] Example Embodiment 33. The method of any of Example Embodiments 7 to 32, wherein network indications for CHO execution activation can be sent, e.g.: per UE granularity; per group of UE granularity. Example Embodiment 34. The method of any of Example Embodiments 7 to 33, wherein network indications for CHO execution activation can be sent e.g.: in a UE-associated signaling message; in a non-UE-associated signaling message.

[0229] Example Embodiment 35. The method of any of Example Embodiments 7 to 34, wherein at least one of:

[0230] • a gNB-CU can send to a gNB-DU a network indication for CHO execution activation in a UE-associated signaling message, hence the content of the signaling applies to one UE only.

[0231] • a gNB-CU can send to a gNB-DU one network indication for CHO execution activation in a non-UE-associated signaling message, the non-UE associated message containing a list of UE, so that the network indication for CHO execution activation applies to all the UEs in the list of UE.

[0232] • a gNB-CU can send to a gNB-DU a non-UE-associated signaling message containing a list of UE where one network indication for CHO execution activation applies to a first set of UEs in the list of UEs, and another network indication for CHO execution activation applies to another (disjoint) set of UEs in the list of UEs.

[0233] • a gNB-DU sends one message / indication / command per UE, the message / indications / command comprising network indication for CHO execution activation which will be applicable only to that UE

[0234] • a gNB-DU sends one message / indication / command per group of UE, the message / indications / command comprising network indication for CHO execution activation which will be applicable to a group of UEs.

[0235] Example Embodiment 36. The method of any of Example Embodiments 7 to 35, wherein the network indication for CHO execution activation are sent to a UE (or a group of UEs, or a list of UEs, or to all UEs in a cell) via a Medium Access Control, MAC, Control Element (CE).

[0236] Example Embodiment 37. The method of any of Example Embodiments 7 to 36, wherein the network indication for CHO execution activation are sent to a UE (or a group of UEs, or a list of UEs, or to all UEs in a cell) via a Downlink Control Information (DCI).

[0237] Example Embodiment 38. The method of any of Example Embodiments 7 to 37, wherein the network indication for CHO execution activation are sent to a UE (or a group of UEs, or a list of UEs, or to all UEs in a cell) via RRC signaling during CHO preparation (or after CHO preparation). In one case, the source RAN node for CHO, includes in an RRC message sent to the UE (e.g., an RRCReconfiguration message comprising the CHO configuration) a priority for associated to a certain candidate cell. In another case, a candidate target RAN node for CHO, includes in an RRC message sent to the UE (e.g., an RRCReconfiguration message comprising the configuration of CHO candidate cells included in the CHO configuration) a priority for associated to a certain candidate cell.

[0238] Example Embodiment 39. A method performed by a second network node for performing a mobility procedure, comprising, optionally receiving from a first network node, an indication to activate CHO execution conditions at the UE; or receiving from a first network node an indication that activation of CHO execution conditions at the UE is pending until, or is subject to, indication from the first network node.

[0239] Example Embodiment 40. The method of Example Embodiment 39, further comprising transmitting to the UE an indication to activate CHO execution conditions.

[0240] Example Embodiment 41. The method of Example Embodiment 39 or 40, wherein at least one of: the first network node comprises a gNB-CU; the second network node comprises a gNB-DU.

[0241] Example Embodiment 42. The method of any of Example Embodiments 39 to 41, wherein, if one or more UEs prepared for CHO have received from the gNB-CU during the CHO preparation an indication that the CHO execution conditions are disabled / (b)locked / not enabled / not allowed, and the gNB-DU - after receiving from the gNB-CU an indication to allow / enable the CHO for one or more UEs - sends to one or more of such UEs an indication / command, e.g., via DCI, to enable / unlock / allow CHO execution.

[0242] Example Embodiment 43. The method of any of Example Embodiment embodiments 39 to 43, wherein the conditional mobility procedure comprises at least one of: NES conditional handover; Conditional Handover; or Conditional LTM; a preparation step; an execution step.

[0243] 44. The method of Example Embodiment 42 or 43, wherein the NES CHO is used to coordinate the offloading of UEs (e.g., from a cell to be deactivated for energy savings reasons) to a number of neighboring gNBs, e.g., the gNB-CU could enable the execution of the NES CHO after receiving assistance information not available at the time of receiving the HANDOVER REQUEST ACKNOWLEDGE messages from the neighboring gNBs. The assistance information received by the gNB-CU may reveal that it is beneficial to execute the conditional handover because the overall performance of the nodes involved in the mobility action (source and target nodes) or the performance of a set of RAN nodes, e.g., a cluster, is optimized with respect to the case where the action is not executed. The performance of neighbouring gNBs can relate to measurements and / or predictions.

[0244] Example Embodiment 45. The method of any of Example Embodiment 39 to 44, under option 2, wherein the transmitting comprises the gNB-CU indicates to the gNB-DU that a CHO that has being prepared or is being prepared towards a target node and is configured at one or more UEs is subject to a later trigger / indication that will be provided by the gNB-CU, where such trigger activates at the UE the execution of the CHO (or the evaluation / activation of the CHO execution conditions).

[0245] Example Embodiment 46. The method of any of Example Embodiments 39 to 45, under option 2, wherein the indication towards the gNB-DU for which the gNB-CU controls the CHO execution condition activation can be generic, i.e., aper-gNB-DU indication (i.e., not pointing to a specific UE, or to a specific group of UEs), or it can be per-UE served by the gNB-DU, or it can be for a group of UEs served by the gNB-DU (e.g., for all UEs in a particular cell) , or it can be per target cell for which a set of UEs have been configured.

[0246] Example Embodiment 47. The method of any of Example Embodiments 39 to 46, wherein the source gNB-CU can indicate to the source gNB-DU that a certain UE is configured (or is being configured or will be configured) for CHO with execution pending network indication before or during the CHO preparation. For example, the gNB-CU can, in an enhanced version of the UE CONTEXT MODIFICATION REQUEST message, indicate that a certain UE is configured (or is being configured, or will be configured) for CHO with execution pending network indication. Optionally the gNB-CU can indicate that the CHO is prepared for a certain purpose, e.g., AI / ML based Network Energy Saving, and / or that the UE is associated with a certain group of UEs.

[0247] Example Embodiment 48. The method of any of Example Embodiments 39 to 47, wherein, in the case of NES CHO, where CHO execution (or CHO execution condition activation) is triggered by a specific Downlink Control Information (DCI) with Cyclic Redundancy Check (CRC) scrambled with a specific RNTI, and the UE is allocated (configured with, or provided) a specific Radio Network Temporary Identifier (RNTI) value to only receive / decode the DCI if the DCFs CRC is scrambled with the specific RNTI value, the gNB-DU can decide to configure a different RNTI value for the UE to monitor taking into account the notification from the gNB-CU that the UE is (will be) configured with a CHO with pending conditions activation (The configured RNTI value is part of the CellGroupConfig IE).

[0248] Example Embodiment 49. The method of Example Embodiment 48, wherein the gNB-DU can then put the modified CellGroupConfig IE in the corresponding UE CONTEXT MODIFICATION RESPONSE message such that the UE will be configured accordingly upon RRC reconfiguration for NES CHO.

[0249] Example Embodiment 50. The method of Example Embodiment 48 or 49, wherein the gNB-CU may read the configured RNTI value from the CellGroupConfig IE or the gNB-DU may explicitly indicate the configured RNTI value to the gNB-CU. In one case, each UE is configured with a different RNTI value. In another case, all UEs configured for NES CHO, or any CHO with execution pending network indication, toward a certain (same) target cell (ID) are configured with a certain (same) RNTI value.

[0250] Example Embodiment 51. The method of any of Example Embodiments 39 to 50, wherein the gNB-CU of the source RAN node that initiated the CHO preparation towards the target RAN node for one or more UEs, determines that the execution of such CHO mobility can / should be triggered for one or more UEs in the set of UEs for which the mobility actions have been prepared.

[0251] Example Embodiment 52. The method of any of Example Embodiments 39 to 51, wherein the source gNB-CU sends a message to the source gNB-DU serving the one or more UEs, indicating that CHO execution can proceed. As a consequence, the source gNB-DU signals to the one or more UEs that execution conditions are activated.

[0252] Example Embodiment 53 The method of any of Example Embodiments 39 to 52, wherein the indication that CHO execution (or evaluation of CHO execution conditions) is allowed / enabled / unlocked is only for UEs currently served by certain source cell(s). Namely, the gNB-CU signals to the gNB-DU that certain specific UEs should be signalled with an indication / command to activate execution conditions only if such UEs are in specific cells indicated by the gNB-CU, e.g. by means of their CGIs.

[0253] Example Embodiment 54. The method of any of Example Embodiments 39 to 53, under option 2, wherein the gNB-CU configures to the gNB-DU conditions according to which the gNB-DU should trigger the signalling towards the UE. These conditions may either be in retrospect or irrespective of the gNB-CU transmitting a signal that evaluation of CHO execution is enabled / unlocked / allowed to the gNB-DU. Such conditions may include one or more of the following:

[0254] • A threshold for an energy consumption metric (or energy cost), where the metric can relate to measurements and / or to predictions, where such metric can be at cell level or at node level or an energy consumption metric (or energy cost) internal to the gNB-DU and that it indicates the threshold at / above / below which the energy consumption metric needs to be for the triggering to take place • Two thresholds for an energy consumption metric (or energy cost), where the metric can relate to measurements and / or to predictions, where such metric can be at cell level or at node level or an energy consumption metric (or energy cost) internal to the gNB-DU and that it indicates the thresholds within which or outside which (as upper bound and lower bound), the energy consumption metric needs to be for the triggering to take place

[0255] • The cell load status; namely a threshold at or above or below which the cell load needs to be for the triggering to take place

[0256] • The activation time for the triggering towards the UE.

[0257] • A maximum activation time to be considered for the triggering towards the UE

[0258] • A suggested activation time to be considered for the triggering towards the UE Example Embodiment 55. The method of any of Example Embodiments 39 to 54, wherein the source gNB-CU determines that it is appropriate to cancel one or more CHO(s) whose activation of CHO execution conditions is(are) pending gNB-CU decision. The gNB- CU in this case sends an indication to cancel the CHO(s) with pending conditions towards the gNB-DU (e g., in a UE CONTEXT MODIFICATION REQUEST message). In the above embodiment the signalling towards the UE may be of different types, for example:

[0259] • A Medium Access Control (MAC) Control Element (CE) signal; or

[0260] • A specific DCI signal.

[0261] Example Embodiment 56. The method of any of Example Embodiments 39 to 55, wherein the gNB-CU triggers UE to start the CHO execution by means of RRC signalling (e.g. light weight RRC signaling). In this scenario where the triggering happens at the RRC-level, the UE may be configured with one or more CHO configurations for which execution conditions have been disabled / locked / not enabled / not allowed. During this time, the source receives information from neighbour nodes that enable the source RAN to evaluate if the CHO towards a certain node is beneficial or not. The gNB-CU may decide to activate / unlock / allow / enable execution conditions of one or more of such CHO configurations depending on the ascertained network state.

[0262] Example Embodiment 57. The method of any of Example Embodiments 39 to 56, wherein the source RAN node prepares the CHO towards a target RAN node, but it does not configure the UE with the CHO configuration. When the source gNB-CU determines that it is appropriate to enable the activation of the CHO execution conditions, the source gNB-CU signals to the UE the CHO configuration including the execution conditions. Such configuration is not subject to further triggering of condition activations, but it implicitly instructs the UE to evaluate execution conditions and, if they are fulfilled, execute the CHO. Note that in this embodiment the source RAN places the configuration towards the UE on hold after having completed the CHO preparation with the target RAN node. During this time, the source receives information from neighbour nodes that enable the source RAN to evaluate if the CHO is beneficial or not. Such information may comprise predictions of the Energy Cost from neighbour nodes taking the prepared CHO into account.

[0263] Example Embodiment 58. The method of any of Example Embodiment 39 to 57, wherein the gNB-CU implicitly triggers the execution of the CHO by signaling to the gNB- DU the execution of another action. For example, if the gNB-CU signals to the gNB-DU the deactivation of one or more cells (e.g., using the Cells to be Deactivated List IE in the F1AP GNB-CU CONFIGURATION UPDATE message), the gNB-DU understands that it should trigger the offloading of all the UEs served by the one or more cells to be deactivated. That can mean that the gNB-DU needs to signal to all the UEs served in the Cell to be deactivated a trigger for CHO condition activation, and UEs that still remains attached to the cell beyond a time after which the trigger was CHO activation was transmitted may be handled separately before the cell is deactivated.

[0264] Example Embodiment 59. The method of any of Example Embodiments 39 to 58, under option 2, wherein when the gNB-CU indicates to the gNB-DU that CHO execution (or CHO execution condition evaluation) can start, the gNB-CU may indicate to the gNB-DU one or more RNTI values, where the RNTI values may be assigned to specific UEs or to groups of UEs. The gNB-DU may then send, for each RNTI value, at least one DCI with CRC scrambled by the respective RNTI value, so that only the subset of UEs configured with, and monitoring, the RNTI value(s) receive / decode the DCI, i.e., only the subset of UEs can proceed with CHO execution condition evaluation (and CHO execution). Alternatively, the gNB-CU may indicate to the gNB-DU one or more target cells (target cell IDs), e.g., in a case where the gNB-DU has allocated / configured a separate RNTI value for each set of UEs configured for a certain target cell (ID). In that case, the network has more control over which UEs to activate the CHO execution conditions for at a certain time.

[0265] Example Embodiment 60. The method of any of Example Embodiments 39 to 59, wherein the source RAN node initiating the CHO preparation, or a function of the source RAN node (e.g., the gNB-CU) determines that CHO execution is subject to network activation. The criteria based on which this determination is done can be called network trigger(s) for activation of CHO execution. Example Embodiment 61. The method of Example Embodiment 60, wherein an example of network trigger(s) for activation of CHO execution is that source RAN node wants to perform HO only if a predicted energy cost received by a potential target RAN node indicates that after the HO is executed the overall energy cost (of the source and target RAN node, or just the energy cost at the target RAN node, or just the energy cost at the source RAN node, will be within certain level(s)). The source RAN node indicates that CHO execution activation is subject to network trigger, as described in the previous embodiments.

[0266] Example Embodiment 62. The method of Example Embodiment 61, wherein later, when the network (e.g., the gNB-CU of the source RAN node) determines that some conditions are satisfied and that CHO execution can start, the network sends network indications / commands for CHO execution activation. These are signaled e.g., from gNB-CU to gNB-DU and / or from gNB-CU / gNB-DU to the UE to indicate that CHO execution can proceed for specific UEs that are allowed to start CHO execution.

[0267] Example Embodiment 63. The method of any of Example Embodiments 39 to 62, wherein network indications for CHO execution activation can be one or more or a combination of the following:

[0268] • indication that CHO execution is pending network initiation

[0269] • indication that a pending CHO execution is allowed / can start

[0270] • indication that a pending CHO execution is not allowed / cannot start

[0271] • a reason (e.g., a cause value) for CHO execution

[0272] • a reason (e.g., a cause value) associated to the CHO for which CHO execution is allowed (or not allowed), e.g., for a UE, or for a group of UEs, for all UEs

[0273] • indication of whether CHO execution for a UE is allowed / can start or is not allowed / cannot start

[0274] • indication of whether CHO execution for a group of UE is allowed / can start or is not allowed / cannot start

[0275] • indication of a UE identity, or a list of UE identities, identifying the UE (or the set of UEs) which will be targeted for network-controlled CHO execution.

[0276] • For example the UE identity can be a Radio Network Temporary Identifier, RNTI, and one or a list of RNTIs can be sent by the gNB-CU to that gNB-DU to indicate which UEs which will be targeted for network controlled CHO execution. The UEs corresponding to the list of RNTIs can be instructed to monitor a DCI format 2_9 with NES event indication bit setindication of other identifiers that may be used to select / deselect a set of UEs that will be targeted for network-controlled CHO execution, e.g., the target cells for which a group of UEs have been configured for.

[0277] Example Embodiment 64. The method of any of Example Embodiments 39 to 63, wherein network indications for CHO execution activation can be sent, e.g.: from a gNB-CU to one or more of the controlled gNB-DU; from a gNB-DU to a UE; from a gNB-DU to a group of UEs; from a gNB-DU to all UEs.

[0278] Example Embodiment 65. The method of any of Example Embodiments 39 to 64, wherein network indications for CHO execution activation can be sent, e.g.: per UE granularity; per group of UE granularity.

[0279] Example Embodiment 66. The method of any of Example Embodiments 39 to 65, wherein network indications for CHO execution activation can be sent e.g.: in a UE-associated signaling message; in a non-UE-associated signaling message.

[0280] Example Embodiment 67. The method of any of Example Embodiments 39 to 66, wherein at least one of:

[0281] • a gNB-CU can send to a gNB-DU a network indication for CHO execution activation in a UE-associated signaling message, hence the content of the signaling applies to one UE only.

[0282] • a gNB-CU can send to a gNB-DU one network indication for CHO execution activation in a non-UE-associated signaling message, the non-UE associated message containing a list of UE, so that the network indication for CHO execution activation applies to all the UEs in the list of UE.

[0283] • a gNB-CU can send to a gNB-DU a non-UE-associated signaling message containing a list of UE where one network indication for CHO execution activation applies to a first set of UEs in the list of UEs, and another network indication for CHO execution activation applies to another (disjoint) set of UEs in the list of UEs.

[0284] • a gNB-DU sends one message / indication / command per UE, the message / indications / command comprising network indication for CHO execution activation which will be applicable only to that UE

[0285] • a gNB-DU sends one message / indication / command per group of UE, the message / indications / command comprising network indication for CHO execution activation which will be applicable to a group of UEs. Example Embodiment 68. The method of any of Example Embodiments 39 to 67, wherein the network indication for CHO execution activation are sent to a UE (or a group of UEs, or a list of UEs, or to all UEs in a cell) via a Medium Access Control, MAC, Control Element (CE).

[0286] Example Embodiment 69. The method of any of Example Embodiments 39 to 68, wherein the network indication for CHO execution activation are sent to a UE (or a group of UEs, or a list of UEs, or to all UEs in a cell) via a Downlink Control Information (DCI).

[0287] Example Embodiment 70. The method of any of Example Embodiments 39 to 69, wherein the network indication for CHO execution activation are sent to a UE (or a group of UEs, or a list of UEs, or to all UEs in a cell) via RRC signaling during CHO preparation (or after CHO preparation). In one case, the source RAN node for CHO, includes in an RRC message sent to the UE (e.g., an RRCReconfiguration message comprising the CHO configuration) a priority for associated to a certain candidate cell. In another case, a candidate target RAN node for CHO, includes in an RRC message sent to the UE (e.g., an RRCReconfiguration message comprising the configuration of CHO candidate cells included in the CHO configuration) a priority for associated to a certain candidate cell.

[0288] Group C Embodiments

[0289] 71. A user equipment for performing or being configured for a mobility procedure, comprising: processing circuitry configured to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the processing circuitry.

[0290] 72. A network node for performing / configuring a UE for, a mobility procedure, the network node comprising: processing circuitry configured to perform any of the steps of any of the Group B embodiments; power supply circuitry configured to supply power to the processing circuitry.

[0291] 73. A user equipment (UE) for [performing or being configured for a mobility procedure, the UE comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry; the processing circuitry being configured to perform any of the steps of any of the Group A embodiments; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a battery connected to the processing circuitry and configured to supply power to the UE.

[0292] ADDITIONAL INFORMATION

[0293] Portions of 3GPP TS 38.473 follow:

[0294] 8.3.4 UE Context Modification (gNB-CU initiated)

[0295] 8.3.4. 1 General

[0296] The purpose of the UE Context Modification procedure is to modify the established UE Context, e.g., establishing, modifying and releasing radio resources or sidelink resources. This procedure is also used to command the gNB-DU to stop data transmission for the UE for mobility (see TS 38.401 [4]). The procedure uses UE- associated signalling.

[0297] Text omitted

[0298] If the NES-CHO Indicator List IE is included in the UE CONTEXT MODIFICATION REQUEST message, the gNB-DU shall, if supported, understand this is related to an NES-CHO condition and will act as specified in TS 38.401. The gNB-DU may signal back to gNB-CU further LI or L2 updates in the UE CONTEXT MODIFICATION RESPONSE message.

[0299] If the CHO Execution Cancel IE is included in the UE CONTEXT MODIFICATION REQUEST message, the gNB-DU shall, if supported, understand a NES-CHO is cancelled and will act as specified in TS 38.401.

[0300] 9.2.2 7 UE CONTEXT MODIFICATION REQUEST

[0301] This message is sent by the gNB-CU to provide UE Context information changes to the gNB-DU.

[0302] Direction: gNB-CU — gNB-DU

[0303] 8.2.x Execution Condition Indication

[0304] 8.2.x. 1 General

[0305] The purpose of the Execution Condition Indication procedure is to indicate to the gNB-DU that the execution condition is fulfilled. The procedure uses non-UE associated signalling.

[0306] 8.2.X.2 Successful Operation

[0307] Figure 8.2.X.2-1: Execution Condition Indication procedure. Successful operation.

[0308] The gNB-CU initiates the procedure by sending an Execution Condition Indication message. Upon reception of the Execution Condition Indication message, the gNB-DU shall, if supported, consider that the conditions indicated in the Execution Condition List IE are fulfilled and the gNB-DU shall, if supported, act as specified in TS 38.401 .

[0309] 8.2.X.3 Unsuccessful Operation

[0310] Not applicable.

[0311] 8.2.X.4 Abnormal Conditions

[0312] Not applicable.

[0313] 9.2. 1 x EXECUTION CONDITION INDICATION This message is sent by the gNB-CU to inform the gNB-DU about the fulfillment of the execution conditions.

[0314] Direction: gNB-CU > gNB-DU.

[0315] TS 38.401

[0316] 8.2. 1.3 Inter-gNB-DU Conditional Handover or Conditional PSCell Change or subsequent CPAC

[0317] This procedure is used for the case when the UE moves from one gNB-DU to another gNB- DU within the same gNB-CU during NR operation for conditional handover or conditional PSCell change or subsequent CPAC. Figure 8.2. 1.3-1 shows the inter-gNB-DU conditional mobility procedure for intra-NR. 1 -2. The steps 1 -2 are as defined in clause 8.2. 1.1.

[0318] 3. The gNB-CU sends an UE CONTEXT SETUP REQUEST message to the candidate gNB-DU to create an UE context and setup one or more data bearers. The UE CONTEXT SETUP REQUEST message is sent for each candidate cell and includes a HandoverPreparationlnformation (conditional handover) or a CG-Configlnfo (conditional PSCell change or subsequent CPAC).

[0319] 4. The candidate gNB-DU responds to the gNB-CU with an UE CONTEXT SETUP RESPONSE message including the target cell ID that was requested from the gNB-CU. The response message is sent for each requested candidate cell.

[0320] 5. If an NES specific event is considered, the gNB-CU sends a UE CONTEXT MODIFICATION REQUEST message to the source gNB-DU to notify the source gNB-DU about the NES specific event being considered, and indicates to the source gNB-DU whether the source gNB-DU shall wait until further notification for execution. The source gNB-DU sends a UE CONTEXT MODIFICATION RESPONSE message to the gNB-CU where the source gNB-DU may include updated DCIs

[0321] 6. The gNB-CU sends a DL RRC MESSAGE TRANSFER message to the source gNB- DU, which includes a generated RRCReconfiguration message.

[0322] 7. The step 7 is as defined in clause 8.2.1.1.

[0323] 8-9. The UE responds to the source gNB-DU with an RRCReconfigurationComplete message, for which the source gNB-DU forwards to the gNB-CU via an UL RRC MESSAGE TRANSFER message.

[0324] 10. The NES specific execution condition is fulfilled.

[0325] 11-12. The gNB-CU sends an EXECUTION CONDITION INDICATION message to the source gNB-DU and indicates that the NES specific condition is fulfilled.

[0326] 13. The source gNB-DU sends a DCI message to the UE indicating that the NES specific condition is fulfilled.

[0327] 14. An execution condition to trigger initiation of conditional handover or conditional PSCell change or subsequent CPAC is fulfilled.

[0328] 15 A Random Access procedure is performed at the candidate gNB-DU, which becomes the target gNB-DU if successful. The target gNB-DU sends a Downlink Data Delivery Status frame to inform the gNB-CU. The target gNB-DU also sends an ACCESS SUCCESS message to inform the gNB-CU of which cell the UE has successfully accessed.

[0329] 16-17. The steps 16-17 are as defined in steps 9-10 in clause 8.2.1.1.

[0330] 18. The gNB-CU sends a UE CONTEXT MODIFICATION REQUEST message to the source gNB-DU and indicates to stop the data transmission for the UE. The source gNB-DU also sends a Downlink Data Delivery Status frame to inform the gNB-CU about the unsuccessfully transmitted downlink data to the UE. Downlink packets, which may include PDCP PDUs not successfully transmitted in the source gNB-DU, are sent from the gNB-CU to the target gNB-DU.

[0331] NOTE 1: The step 18 may happen before step 17, as soon as the gNB-CU knows which cell the UE has successfully accessed.

[0332] NOTE 2: The gNB-CU may initiate UE Context Release procedure toward the other signalling connections or other candidate target gNB-DUs, if any, to cancel conditional handover or conditional PSCell change for the UE.

[0333] 19. The source gNB-DU responds to the gNB-CU with the UE CONTEXT MODIFICATION RESPONSE message.

[0334] 20 -21. The steps 20-21 are as defined in steps 11-12 in clause 8.2.1.1.

[0335] The step 20-21 shall not happen if all of the PSCells in the source gNB-DU remain configured as the candidate PSCell(s) in the subsequent CPAC.

Claims

CLAIMS1. A method (100) performed by a gNodeB Central Unit, gNB-CU, for configuring a conditional mobility procedure, the method comprising: triggering (102) activation of at least one execution condition for the conditional mobility procedure for at least one User Equipment, UE (312).

2. The method of Claim 1, wherein triggering activation of the at least one execution condition comprises transmitting, to a gNodeB Distributed Unit, gNB-DU, a first indication to activate the at least one execution condition for the conditional mobility procedure.

3. The method of Claim 1, wherein triggering activation of the at least one execution condition comprises transmitting, to the at least one UE, a second indication to activate the at least one execution condition for the conditional mobility procedure.

4. The method of any one of Claims 2 to 3, comprising transmitting a third indication that activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is pending until the first indication or the second indication is received from the gNB-CU.

5. The method of Claim 4, wherein the third indication is transmitted to a gNodeB Distributed Unit, gNB-DU, and wherein the third indication indicates at least one of the activation of the at least one execution condition for the conditional mobility procedure is pending for a single UE; the activation of the at least one execution condition for the conditional mobility procedure is pending for a group of UEs; the activation of the at least one execution condition for the conditional mobility procedure is pending for one or more target cells or one or more source cells; and the activation of the at least one execution condition for the conditional mobility procedure is pending for any UEs that are served by the gNB-DU.

6. The method of any one of Claims 2 to 5, wherein at least one of the first indication, the second indication, and the third indication identifies a Radio Network Temporary Identifier associated with the at least one UE.

7. The method of any one of Claims 1 to 6, wherein at least one of the activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is for a single UE; the activation of the at least one execution condition for the conditional mobilityprocedure for the at least one UE is for a group of UEs; the activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is for one or more target cells or one or more source cells; and the activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is for any UEs that are served by a gNodeB Distributed Unit, gNB-DU.

8. The method of any one of Claims 1 to 7, comprising: determining that it is beneficial to execute the conditional mobility procedure for the at least one UE; and triggering the activation of the at least one execution condition for the conditional mobility procedure for the at least one UE based on determining that it is beneficial to execute the conditional mobility procedure for the at least one UE.

9. The method of Claim 8, comprising: receiving assistance information; and wherein the gNB-CU determines that it is beneficial to execute the conditional mobility procedure for the at least one UE based on the assistance information.

10. The method of Claim 9, wherein the assistance information is received after receiving one or more HANDOVER REQUEST ACKNOWLEDGE messages from one or more neighboring network nodes.

11. The method of any one of Claims 1 to 10, wherein the conditional mobility procedure comprises at least one of: a NES conditional handover; a Conditional Handover; or a Conditional Layerl / Layer 2 Triggered Mobility, LTM.

12. The method of any one of Claims 1 to 11, comprising transmitting, to a gNodeB Distributed Unit, gNB-DU, an indication that a particular UE is or will be configured for the conditional mobility procedure with execution pending network indication before or during preparation for the conditional mobility procedure.

13. The method of any one of Claims 1 to 12, wherein triggering activation of the at least one execution condition for the conditional mobility procedure for the at least one UE comprises: completing preparation for the conditional mobility procedure with the target network node;determining that the conditional mobility procedure is beneficial to the network; and based on determining that the conditional mobility procedure is beneficial to the network, transmitting a handover command and / or the at least one execution condition.

14. The method of any one of Claims 1 to 13, comprising signaling, to the gNB-DU, an indication of deactivation of one or more cells, wherein the gNB-DU is configured to signal, to the at least one UE served in the one or more cells to be deactivated, a trigger for activation of the at least one execution condition.

15. The method of any one of Claims 1 to 14, comprising transmitting at least one network indication for triggering activation of the at least one execution condition, wherein the at least one network indication comprises at least one of an indication that execution of the conditional mobility procedure is pending network initiation, an indication that a pending execution of the conditional mobility procedure is allowed and / or can start, an indication that a pending execution of the conditional mobility procedure is not allowed and / or cannot start, a reason or a cause value for execution of the conditional mobility procedure, and an indication of a UE identity or a list of UE identities that will be targeted for execution of the conditional mobility procedure.

16. The method of any one of Claims 1 to 15, comprising transmitting, to a gNodeB Distributed Unit, gNB-DU, at least one trigger condition for triggering signaling towards the at least one UE.

17. The method of Claim 16, wherein the at least one trigger condition for triggering signaling towards the at least one UE comprise at least one of at least one threshold for an energy consumption metric and / or energy cost, at least one threshold associated with a cell load, an activation time for triggering the conditional mobility procedure for the at least one UE, a maximum activation time for the triggering the conditional mobility procedure for the at least one UE, and a suggested activation time for the triggering the conditional mobility procedure for the at least one UE.

18. A method (200) performed by a gNodeB Distributed Unit, gNB-DU, for configuring a conditional mobility procedure, the method comprising at least one of receiving (202), from a gNodeB Central Unit, gNB-CU, a first indication to activate at least one execution condition for the conditional mobility procedure for at least one User Equipment, UE; and / or receiving (204), from the gNB-CU, a third indication that activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is pending until the first indication is received from the gNB-CU or until a second indication from the gNB-CU is received by the at least one UE.

19. The method of Claim 18, comprising transmitting, to the at least one UE, a fourth indication to activate the at least one execution condition for the conditional mobility procedure.

20. The method of any one of Claims 18 to 19, wherein at least one of the first indication and the third indication is for at least one of a single UE, a group of UEs, one or more target cells or one or more source cells, and any UEs that are served by the gNB-DU.

21. The method of any one of Claims 18 to 20, wherein the activation of the at least one execution condition for the conditional mobility procedure is for at least one of a single UE, a group of UEs, one or more target cells or one or more source cells, and any UEs that are served by the gNB-DU.

22. The method of any one of Claims 18 to 21, wherein at least one of the first indication, the second indication, the third indication, and the fourth indication identifies a Radio Network Temporary Identifier associated with the at least one UE.

23. The method of any one of Claims 18 to 22, wherein at least one of the first indication and the third indication indicates that the conditional mobility procedure for the at least one UE is beneficial for the network.

24. The method of any one of Claims 18 to 23, wherein the conditional mobility procedure comprises at least one of a NES conditional handover; a Conditional Handover; or aConditional Layer 1 / Layer 2 Triggered Mobility, LTM.

25. The method of any one of Claims 18 to 24, comprising receiving, from the gNB-CU, an indication to cancel the conditional mobility procedure for the at least one UE.

26. The method of any one of Claims 18 to 25, comprising: receiving, from the gNB-CU, an indication of deactivation of one or more cells; and signaling, to the at least one UE served in the one or more cells to be deactivated, a trigger for activation of the at least one execution condition.

27. The method of any one of Claims 18 to 26, comprising receiving, from the gNB-CU, at least one network indication for triggering activation of the at least one execution condition, wherein the at least one network indication comprises at least one of: an indication that execution of the conditional mobility procedure is pending network initiation, an indication that a pending execution of the conditional mobility procedure is allowed and / or can start, an indication that a pending execution of the conditional mobility procedure is not allowed and / or cannot start, a reason or a cause value for execution of the conditional mobility procedure, and an indication of a UE identity or a list of UE identities that will be targeted for execution of the conditional mobility procedure.

28. The method of any one of Claims 18 to 27, comprising receiving, from the gNB-CU, at least one trigger condition for triggering signaling towards the at least one UE.

29. The method of Claim 28, wherein the at least one trigger condition for triggering signaling towards the at least one UE comprise at least one of: at least one threshold for an energy consumption metric and / or energy cost, at least one threshold associated with a cell load, an activation time for triggering the conditional mobility procedure for the at least one UE, a maximum activation time for the triggering of the conditional mobility procedure for the at least one UE, and a suggested activation time for the triggering of the conditional mobility procedure for the at least one UE.

30. The method of any one of Claims 18 to 29, comprising receiving, from the gNB-CU, an indication that a particular UE is or will be configured for the conditional mobility procedure with execution pending network indication before or during preparation for the conditional mobility procedure.

31. A gNodeB Central Unit, gNB-CU, for configuring a conditional mobility procedure comprises a memory and a processor, the gNB-CU is configured to: trigger (102) activation of at least one execution condition for the conditional mobility procedure for at least one User Equipment, UE (312).

32. The gNB-CU of Claim 31, configured to perform any of the methods of Claims 2 to 17.

33. A gNodeB Distributed Unit, gNB-DU, for configuring a conditional mobility procedure comprises a memory and a processor, the gNB-DU is configured to perform at least one of: receiving (202), from a gNodeB Central Unit, gNB-CU, a first indication to activate at least one execution condition for the conditional mobility procedure for at least one User Equipment, UE (312); and / or receiving (204), from the gNB-CU, a third indication that activation of the at least one execution condition for the conditional mobility procedure for the at least one UE is pending until the first indication is received from the gNB-CU or until a second indication from the gNB-CU is received by the at least one UE.

34. The gNB-DU of Claim 33, configured to perform any of the methods of Claims 19 to30.

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