Conditional handover configuration for fast offload during cell shutdown

Abstract

Systems, methods, apparatus, and non-transitory computer readable media for conditional switching configuration for fast offload during cell shutdown. For example, a method includes receiving, with a user equipment, one or more handover configurations from a serving cell. The one or more switching configurations include an energy saving condition switching configuration. At least one of the one or more handover configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection. The method also includes receiving, from the serving cell, an indication of energy saving mode activation at the serving cell. The method also includes selecting a target cell from the one or more candidate target cells based at least in part on the one or more handover configurations and the received indication of the energy saving mode activation at the serving cell.

Description

Technical Field

[0001] The exemplary and non-limiting embodiments relate generally to network communications, and more particularly to handover procedures. Background Art

[0002] As is known to all, in network communications, performing cell shutdown can achieve energy saving. Summary of the invention

[0003] The following abstract is intended for illustration only. The abstract is not intended to limit the scope of the claims.

[0004] According to one aspect, a device includes: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, enable the device to at least: receive one or more switching configurations from a serving cell, wherein the one or more switching configurations include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection; receive an indication of activation of an energy-saving mode at the serving cell from the serving cell; and select a target cell from the one or more candidate target cells based at least in part on the one or more switching configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0005] According to one aspect, a method includes: using a user equipment to receive one or more switching configurations from a serving cell, wherein the one or more switching configurations include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection; receiving an indication of activation of an energy-saving mode at the serving cell from the serving cell; and selecting a target cell from the one or more candidate target cells based at least in part on the one or more switching configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0006] According to one aspect, a device includes a device for performing the following: receiving one or more switching configurations from a serving cell, wherein the one or more switching configurations include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection; receiving an indication of activation of an energy-saving mode at the serving cell from the serving cell; and selecting a target cell from the one or more candidate target cells based at least in part on the one or more switching configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0007] According to one aspect, a non-transitory computer-readable medium includes program instructions stored thereon, which, when executed by at least one processor, cause the at least one processor to: cause one or more switching configurations to be received from a serving cell, wherein the one or more switching configurations include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection; cause an indication of activation of an energy-saving mode at the serving cell to be received from the serving cell; and select a target cell from the one or more candidate target cells based at least in part on the one or more switching configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0008] According to one aspect, a device includes: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, enable the device to at least: determine to activate an energy-saving mode; generate one or more switching configurations, wherein the one or more switching configurations include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection; transmit the one or more switching configurations to a user equipment; start activating the energy-saving mode; and transmit an indication of the activation of the energy-saving mode to the user equipment.

[0009] According to one aspect, a method includes: determining to activate an energy-saving mode; generating one or more handover configurations, wherein the one or more handover configurations include an energy-saving conditional handover configuration, wherein at least one of the one or more handover configurations includes an indication of one or more candidate target cells or at least one of information for target cell selection; transmitting the one or more handover configurations to a user equipment; starting to activate the energy-saving mode; and transmitting an indication of the energy-saving mode activation to the user equipment. According to one aspect, a device includes means for performing the following: determining to activate an energy-saving mode; generating one or more handover configurations, wherein the one or more handover configurations include an energy-saving conditional handover configuration, wherein at least one of the one or more handover configurations includes an indication of one or more candidate target cells or at least one of information for target cell selection; transmitting the one or more handover configurations to a user equipment; starting to activate the energy-saving mode; and transmitting an indication of the energy-saving mode activation to the user equipment.

[0010] According to one aspect, a non-transitory computer-readable medium includes program instructions stored thereon, which, when executed by at least one processor, cause the at least one processor to: determine to activate an energy-saving mode; generate one or more switching configurations, wherein the one or more switching configurations include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection; cause the one or more switching configurations to be transmitted to a user device; start activating the energy-saving mode; and cause an indication of the activation of the energy-saving mode to be transmitted to the user device.

[0011] According to one aspect, a computer program includes instructions stored thereon for performing at least the following: receiving one or more switching configurations from a serving cell, wherein the one or more switching configurations include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection; receiving an indication of activation of an energy-saving mode at the serving cell from the serving cell; and selecting a target cell from the one or more candidate target cells based at least in part on the one or more switching configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0012] According to one aspect, a computer program includes instructions stored thereon for performing at least the following: determining to activate an energy-saving mode; generating one or more switching configurations, wherein the one or more switching configurations include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection; transmitting the one or more switching configurations to a user device; starting to activate the energy-saving mode; and transmitting an indication of activation of the energy-saving mode to the user device. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above aspects and various other features are explained in the following description in conjunction with the accompanying drawings, in which:

[0014] Figure 1 is a block diagram of one possible and non-limiting example system in which example embodiments may be practiced;

[0015] Figure 2 is a diagram illustrating a number of features as described herein;

[0016] FIG3 is a flow chart showing a plurality of steps as described herein;

[0017] Figure 4is a diagram illustrating a number of features as described herein;

[0018] Figure 5 is a flow chart showing a number of steps as described herein;

[0019] Figure 6 is a flow chart showing a number of steps as described herein;

[0020] Figure 7 is a flowchart showing a plurality of steps as described herein; and

[0021] Figure 8 is a flow chart showing various steps as described herein. DETAILED DESCRIPTION

[0022] The following abbreviations that may be found in the specification and / or drawings are defined as follows:

[0023] 3GPP Third Generation Partnership Project

[0024] 5G Fifth Generation

[0025] 5GC 5G Core Network

[0026] AI

[0027] AMF Access and Mobility Management Function

[0028] BB Baseband

[0029] CE Control Elements

[0030] CHO Condition Switch

[0031] CN Core Network

[0032] CPC Condition PS Cell Change

[0033] CSI-RS Channel State Information Reference Signal

[0034] CU Central Unit

[0035] DCI Downlink Control Information

[0036] DL Downlink

[0037] DRX Discontinuous Reception

[0038] DTX Discontinuous Transmission

[0039] DU Distributed Unit

[0040] eDRX Extended Discontinuous Reception

[0041] eMBB Enhanced Mobile Broadband

[0042] eMTC Enhanced Machine Type Communication

[0043] eNB (or eNodeB) Evolved Node B (e.g., LTE base station)

[0045] EN-DC E-UTRA-NR Dual Connectivity

[0046] The en-gNB or En-gNB provides NR user plane and control plane protocol termination to the UE and acts as the EN-DC The node of the secondary node ES Energy Saving

[0047] ES-CHO Energy saving special condition switching

[0048] E-UTRA Evolved Universal Terrestrial Radio Access, also known as LTE radio access technology

[0049] gNB (or gNodeB) 5G / NR base station, i.e., providing NR user plane and control plane protocol termination to the UE and Nodes connected to 5GC via NG interface

[0050] HFN Very High Frame Number

[0051] HO Switchover

[0052] IE Information Elements

[0053] I / F Interface

[0054] L1 Layer 1 LTE Long Term Evolution MAC Media Access Control (m)MIMO (Massive Multiple-Input Multiple-Output) ML Machine Learning MME Mobility Management Entity ng or NG new generation ng-eNB or NG-eNB Next Generation eNB NR New Radio N / W or NW network O&M Operation and Maintenance OFDM Orthogonal Frequency Division Multiplexing OPEX Operating Expenses PBCH Physical Broadcast Channel PDCP Packet Data Convergence Protocol PHY Physical Layer PoC Push to Talk over Cellular PSG Power Saving Group PSW Power Saving Window RA Registration Area RAN Radio Access Network RAT Radio Access Technology RedCap reduced capabilities RF RLC Radio Link Control RNA RAN-based notification area RRC Radio Resource Control RRH Remote Radio Head RRM Radio Resource Management RS reference signal RSRP refers to Reference Signal Received Power RSRQ Reference Signal Received Quality RU Radio Unit Rx Receiver SDAP Service Data Adaptation Protocol SFN System Frame Number SGW Service Gateway

[0055] SI System Information

[0056] SIB System Information Block

[0057] SINR Signal to Interference and Noise Ratio

[0058] SMF session management functions

[0059] SS Sync Signal

[0060] SSB Synchronous Signal Block

[0061] TA Tracking Area

[0062] TCI Transmission Configuration Indicator

[0063] TRX Transceiver

[0064] Tx Transmitter

[0065] UE User Equipment (e.g., wireless device, typically a mobile device)

[0066] UPF User Plane Function

[0067] Steering Figure 1 , this figure shows a block diagram of one possible and non-limiting example in which the examples may be practiced. A user equipment (UE) 110, a radio access network (RAN) node 170 and a network element 190 are shown. Figure 1In the example of , user equipment (UE) 110 wirelessly communicates with wireless network 100. UE is a wireless device capable of accessing wireless network 100. UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected by one or more buses 127. Each transceiver in one or more transceivers 130 includes a receiver Rx 132 and a transmitter Tx 133. One or more buses 127 can be an address bus, a data bus, or a control bus, and can include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, an optical fiber or other optical communication device, etc. One or more transceivers 130 are connected to one or more antennas 128. One or more memories 125 include computer program code 123. UE 110 includes module 140, which includes one or both of parts 140-1 and / or 140-2 that can be implemented in many ways. Module 140 can be implemented in hardware as module 140-1, such as being implemented as part of one or more processors 120. Module 140-1 may also be implemented as an integrated circuit or by other hardware such as a programmable gate array. In another example, module 140 may be implemented as module 140-2, which is implemented as computer program code 123 and executed by one or more processors 120. For example, one or more memories 125 and computer program code 123 may be configured to perform one or more of the operations described herein with user equipment 110 together with one or more processors 120. UE 110 communicates with RAN node 170 via wireless link 111.

[0068] In this example, the RAN node 170 is a base station that provides access to the wireless network 100 by wireless devices such as UE 110. The RAN node 170 may be, for example, a 5G base station, also known as a new radio (NR). In 5G, the RAN node 170 may be an NG-RAN node, which is defined as a gNB or ng-eNB. A gNB is a node that provides NR user plane and control plane protocol termination to the UE and is connected to a 5GC (such as, for example, network element 190) via an NG interface. An ng-eNB is a node that provides E-UTRA user plane and control plane protocol termination to the UE and is connected to the 5GC via an NG interface. The NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and a distributed unit (DU) (gNB-DU), of which DU 195 is shown. Note that the DU may include or be coupled to and control a radio unit (RU). The gNB-CU is a logical node that hosts the RRC, SDAP, and PDCP protocols of a gNB or controls the operation of the RRC and PDCP protocols of an en-gNB for one or more gNB-DUs. The gNB-CU terminates the F1 interface connected to the gNB-DU. The F1 interface is shown as reference numeral 198, although reference numeral 198 also shows a link between a remote element of the RAN node 170 and a centralized element of the RAN node 170, such as between a gNB-CU 196 and a gNB-DU 195. The gNB-DU is a logical node that hosts the RLC, MAC, and PHY layers of a gNB or en-gNB, and its operation is partially controlled by the gNB-CU. One gNB-CU supports one or more cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface 198 connected to the gNB-CU. Note that DU 195 is considered to include transceiver 160, e.g., as part of a RU, but some examples in this regard may have transceiver 160 as part of a separate RU, e.g., under the control of and connected to DU 195. RAN node 170 may also be an eNB (evolved Node B) base station for LTE (Long Term Evolution), or any other suitable base station or node.

[0069] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N / WI / F) 161, and one or more transceivers 160 interconnected by one or more buses 157. Each of the one or more transceivers 160 includes a receiver Rx 162 and a transmitter Tx 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include the processor 152, the memory 155, and the network interface 161. Note that the DU 195 may also include its own one / more memories and processors, and / or other hardware, but these are not shown.

[0070] The RAN node 170 includes a module 150, which includes one or both of the parts 150-1 and / or 150-2, which can be implemented in many ways. The module 150 can be implemented in hardware as the module 150-1, such as being implemented as part of one or more processors 152. The module 150-1 can also be implemented as an integrated circuit or by other hardware such as a programmable gate array. In another example, the module 150 can be implemented as a module 150-2, which is implemented as a computer program code 153 and executed by one or more processors 152. For example, one or more memories 155 and the computer program code 153 are configured to, together with the one or more processors 152, cause the RAN node 170 to perform one or more of the operations described herein. Note that the functionality of the module 150 may be distributed, such as distributed between the DU 195 and the CU 196, or implemented solely in the DU 195.

[0071] One or more network interfaces 161 communicate over a network, such as via links 176 and 131. Two or more gNBs 170 may communicate using, for example, link 176. Link 176 may be wired or wireless or both, and may implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interfaces for other standards.

[0072] The one or more buses 157 may be an address bus, a data bus, or a control bus, and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, optical fiber or other optical communication device, a wireless channel, etc. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for a gNB implementation of 5G, where other elements of the RAN node 170 may be physically located at a different location from the RRH / DU, and the one or more buses 157 may be partially implemented as, for example, a fiber optic cable or other suitable network connection to connect the other elements of the RAN node 170 (e.g., central unit (CU), gNB-CU) to the RRH / DU 195. Reference numeral 198 also indicates those suitable network links.

[0073] Please note that the description herein indicates that a "cell" performs multiple functions, but it should be clear that the equipment forming the cell will perform the multiple functions. The cell constitutes part of the base station. That is, each base station can have multiple cells. For example, a single carrier frequency and associated bandwidth can have three cells, each covering one-third of a 360-degree area, so that the coverage area of ​​a single base station covers an approximate ellipse or circle. In addition, each cell can correspond to a single carrier, and the base station can use multiple carriers. Therefore, if each carrier has three 120-degree cells and there are two carriers, then the base station has a total of 6 cells.

[0074] The wireless network 100 may include one or more network elements 190, which may include core network functionality and provide connectivity to other networks such as telephone networks and / or data communication networks (e.g., the Internet) via one or more links 181. Such core network functionality for 5G may include (multiple) access and mobility management functions (AMFs) and / or (multiple) user plane functions (UPFs) and / or (multiple) session management functions (SMFs). Such core network functionality for LTE may include MME (mobility management entity) / SGW (serving gateway) functionality. These are merely illustrative functions that the network element 190 may support, and please note that both 5G functions and LTE functions may be supported. The RAN node 170 is coupled to the network element 190 via a link 131. The link 131 may be implemented as, for example, an NG interface for 5G, or an S1 interface for LTE, or other suitable interfaces for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N / WI / F) 180 interconnected by one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and computer program code 173 are configured to, together with the one or more processors 175, cause the network element 190 to perform one or more operations.

[0075] Wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single software-based management entity (virtual network). Network virtualization involves platform virtualization, which is often combined with resource virtualization. Network virtualization is categorized as either external network virtualization, which combines many networks or parts of networks into a virtual unit, or internal network virtualization, which provides network-like functionality to software containers on a single system. Note that hardware such as processors 152 or 175 and memories 155 and 171 are still used to some extent to implement virtualized entities resulting from network virtualization, and such virtualized entities also produce technical effects.

[0076] Computer readable memories 125, 155, and 171 may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Computer readable memories 125, 155, and 171 may be devices for performing various storage functions. As non-limiting examples, processors 120, 152, and 175 may be of any type suitable for the local technical environment and may include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Processors 120, 152, and 175 may be devices for performing various functions, such as controlling UE 110, RAN node 170, and other functions as described herein.

[0077] In general, various embodiments of user equipment 110 may include, but are not limited to, cellular telephones such as smart phones, tablet computers, personal digital assistants (PDAs) with wireless communication capabilities, portable computers with wireless communication capabilities, image capture devices such as digital cameras with wireless communication capabilities, gaming devices with wireless communication capabilities, music storage and playback devices with wireless communication capabilities, Internet devices allowing wireless Internet access and browsing, tablet computers with wireless communication capabilities, and portable units or terminals incorporating combinations of such functionality.

[0078] Features as described herein generally relate to network energy saving enhancements in 5G NR and future technologies (e.g., 6G). More specifically, features as described herein may generally relate to conditional switching features of 5G NR that may be used during cell shutdown to achieve network energy saving.

[0079] Reducing the energy consumption of mobile networks, especially the energy consumption of the RAN, which accounts for the largest part of the total network energy consumption, has received extensive attention. Research on network energy saving will be carried out in 3GPP Rel.18 and may aim to determine network energy saving techniques in the time domain, frequency domain, spatial domain and / or power domain for both transmission and reception. Potential support / feedback from UE, potential UE assistance information and information exchange / coordination through network interfaces may also fall within the scope of the study (RP-213554).

[0080] In Rel.18, there will also be an Artificial Intelligence (AI) / Machine Learning (ML) work item for NG-RAN (RP-213602) based on the Rel.17 study, and the research project description is included in RP-201620 "NR and EN-DC data collection enhancement study". The work item aims to specify data collection enhancements and signaling support within the existing NG-RAN interface and architecture for many AI / ML-based use cases. One of the use cases is energy saving.

[0081] Energy saving functionality has been introduced to reduce network energy consumption and energy related operating expenses whenever possible. Energy saving deployments consider capacity boosting cells which are deployed on top of coverage cells to enhance the capacity of single or dual connected E-UTRA or NR. These cells are allowed to be optimized by shutting down when capacity is not required and reactivating as needed. Shutting down cells can be done by OAM and the NG-RAN node that owns the capacity cell, which can autonomously shut down the cell using, for example, cell load information. Shutting down cells during low load periods is one of the most effective means to achieve network energy saving, as all power consuming hardware components of the cell can be shut down, and therefore significant energy consumption reduction can be achieved. In a cell shutdown scenario, power consumption may be reduced by 10-15% when the cell is shut down compared to when the cell is not shut down. Now refer to Figure 2 , shows an example of a cell shutdown feature. A Power Saving Group (PSG) is a group of cells covering the same area (i.e. frequency layer). Figure 2 In the example of , PSG-1 includes two cells 210a and 210b covering the same area at different frequencies; PSG-2 includes two cells 220a and 220b covering the same area at different frequencies; and PSG-3 includes two cells 230a and 230b covering the same area at different frequencies. Figure 2 In the example of , each PSG consists of two frequency layers, but this example is non-limiting; a greater or lesser number of frequency layers may be included in a greater or lesser number of PSGs.

[0082] Cells can be turned off to save energy. Energy saving can result in saving operating expenditure (OPEX). For each PSG, the load can be compared to one or more thresholds. If the load is below a threshold, the cell can be turned off. If the load is greater than another threshold, the cell can be turned on again. The threshold can be predetermined. The comparison of the load of the PSG can be compared to a threshold. In low traffic conditions, (multiple) layers of the PSG can be turned off without excessively degrading network performance while saving energy.

[0083] As described above, the cell shutdown process can provide potential energy savings. In addition, other measures can be taken to save energy while the cell is still active. For example, radio frequency (RF) path micro-cutting (e.g., micro discontinuous transmission (DTX)) can result in a 10-20% reduction in power consumption (e.g., more than 40% reduction in no-load conditions). This means that when no transmission is performed, RF power consumption can be reduced with RF path micro-cutting. As another example, power consumption can be reduced by 10-30% through (massive) multiple-input multiple-output ((m)MIMO) muting. In the first case, for example, half of the transceivers can be shut down horizontally. In the second case, for example, half of the transceivers can be shut down vertically. If the baseband components can also be shut down, power consumption can be further reduced.

[0084] Features as described herein generally relate to conditional handover (CHO) defined in 5G NR Release 16. This new handover procedure may allow a UE to perform a handover when certain handover conditions are met. In other words, CHO is a handover performed by the UE when the configured execution conditions are met, without the need for the network to issue a handover command. This process may have the technical effect of avoiding delays associated with network control procedures and reducing handover failures.

[0085] Once a decision is made to shut down a cell (e.g., autonomously by the cell or by an operations and management function (O&M)), the UEs currently connected to the cell need to be unloaded from the cell before the shutdown can be completed. This can be done by handing over each connected UE to a neighboring cell, which may have overlapping coverage and can use conventional handover to accommodate the additional load. The neighboring cell may belong to a coverage layer, or to another frequency layer (e.g., where the shutdown is performed at a PSG of a given frequency layer). If the unloading is not completed before the cell is shut down, a handover (HO) failure may occur. Faster unloading can bring about the technical effect of increasing power consumption reduction.

[0086] However, using conventional handover to offload traffic from a cell can be quite slow. The process may require multiple consecutive steps to gradually reduce the transmit power of (e.g., synchronization signal blocks (SSBs)), which in turn may reduce the received signal strength (reference signal received power / reference signal received quality (RSRP / RSRQ)) observed by the UE. A UE in RRC connected mode may perform radio resource management (RRM) measurements (RSRP / RSRQ) of the serving cell and neighboring cells and report these measurements to the network. This can help the network identify relevant neighboring cells that can be used for UE handover given the radio conditions of the UE. For example, when the RSRP of the target cell becomes better than the RSRP of the serving cell by a defined offset, the UE may trigger an A3 event (triggered when the neighboring cell becomes better than the serving cell by an offset) and send a measurement report (indicating the best candidate cell) to the serving cell. After determining the target cell for a given UE based on the UE RRM measurement report, the serving cell may eventually prepare the selected cell through Xn and trigger the handover by sending a handover command to the UE. However, the handover process may be affected by handover failures. Whenever a handover fails, the UE should perform cell selection and then perform reconstruction. As a result, the UE may perform a re-establishment to the source cell and may have to repeat the handover procedure (ie to the target cell) (eg if the handover condition persists).

[0087] Example embodiments of the present disclosure may have the technical effect of allowing cells to be unloaded more quickly before they are powered off (eg, avoiding HO failures), thereby improving power consumption reduction.

[0088] According to TS 38.331 Section 5.3.5.13 “Conditional Reconfiguration”, the CHO configuration (ConditionalReconfiguration-r16 in RRCReconfig) provided by the source gNB to the UE may include the following information elements (IEs): candidate target special cells prepared for conditional handover (generated by the candidate gNB); execution criteria (e.g., the criteria that the UE should use for conditional reconfiguration execution generated by the source gNB (i.e., controlling when CHO is triggered)); and / or RS type (SSB-based or Channel State Information Reference Signal (CSI-RS)) (e.g., the RS that the UE should use to obtain beam and cell measurement results, which are used to evaluate the conditional reconfiguration execution conditions). Please note that CHO only supports a single reference signal type, and up to two different trigger quantities (e.g., RSRP and RSRQ, RSRP and SINR, etc.) can be configured simultaneously for evaluating the CHO execution conditions of a single candidate cell.

[0089] It may be noted that TS 38.331 specifies that if the UE is configured with CHO configuration and before the CHO execution conditions are met, a HO command may be received from the gNB. The UE may trigger a handover based on the received HO command without waiting for any CHO conditions to be met. This means that a legacy HO command may take precedence over a CHO configuration (if configured).

[0090] Up to 8 CHO configurations can be configured for a UE (depending on UE capabilities). Each CHO configuration may consist of a CHO ID, 1 to 2 MeasIDs (e.g. one with RSRP and another with RSRQ) and / or (intra-RAT) HO commands.

[0091] Once triggered, CHO can be performed as a normal switch.

[0092] In contrast to the example embodiments of the present disclosure, in conventional CHO, the UE may start evaluating the CHO execution condition upon receiving the CHO configuration, and may stop evaluating the execution condition after performing the handover.

[0093] Referring now to FIG. 3 , a basic access and mobility management function / user plane function (AMF / UPF) intra-conditional handover scenario is shown, as described in TS 338.300. At 302, user data may be transmitted between the UE and the source gNB. At 304, user data may be transmitted between the source gNB and the UPF. At 306, mobility control information may be provided to the source gNB by the AMF. At 308, measurement control reports may be transmitted between the UE and the source gNB. At 310, the source gNB may make a CHO decision, for example, based on the information of the measurement and control reports. At 312, the gNB may send one or more handover requests to the target gNB. At 314, the source gNB may send one or more handover requests to other potential target gNBs; this step may be optional. At 316, the target gNB may perform admission control. At 318, the other potential target gNBs may optionally perform admission control. At 320, the target gNB may send one or more handover request acknowledgments to the source gNB. At 322, the other potential target gNBs may send one or more handover request acknowledgments to the source gNB. At 324, the source gNB may send an RRC reconfiguration message to the UE. At 326, the UE may send an RRC reconfiguration complete message to the source gNB. Steps 302 to 326 may be considered part of handover preparation 350.

[0094] At 328, the UE may evaluate the CHO conditions. At 330, the UE may detach from the old cell (source gNB) and synchronize to the new cell (target gNB or other potential target gNB). At 332, the source gNB may optionally send an early status transfer to the other potential target gNBs. At 334, the UPF may send user data to the source gNB, and the source gNB may optionally forward the user data to the other potential target gNBs. At 336, the UE, the source gNB, and the target gNB may complete the CHO handover. Steps 328 to 336 may be considered part of the handover execution 360.

[0095] At 338, the target gNB may send a handover success message to the source gNB. At 340, the source gNB may perform an SN status transfer to the target gNB. At 342, the UPF may send user data to the source gNB, and the source gNB may forward the user data to the target gNB. At 344, the source gNB may send a handover cancel message to the target gNB and optionally to other potential target gNBs. Steps 338 to 344 may be considered part of handover completion 370.

[0096] Reference now Figure 4 , shows an example of a ConditionalReconfiguration IE (410) that can be used to add, modify and / or publish the configuration of a conditional reconfiguration (TS 38.423). As described in the ConditionalReconfiguration field description (420), if the selected cell is a target candidate cell and it is the first cell selection after a failure, the attemptCondReconfig field can be used to cause the UE to perform a conditional reconfiguration. The condReconfigToAddModList field can be used to provide a list of configurations of candidate special cells to be added or modified for CHO or CPC. The condReconfigToRemoveList field can be used to provide a list of configurations of candidate special cells to be removed.

[0097] A portion of a handover request from the source NG-RAN node to the target NG-RAN node requesting preparation of resources for handover is shown in Table 1:

[0098]

[0099] Table 1

[0100] The "estimated arrival probability" may enable the target node to apply some statistical resource optimization based on the estimated arrival probability (where 100% may be interpreted as the UE arriving with certainty as in "classic HO").

[0101] A technical effect of example embodiments of the present disclosure may be to achieve conditional switching enhancement to save energy.

[0102] In an example embodiment, the network may configure one or more Energy Saving Specific Conditional Handover (ES-CHO) configurations for a UE in an RRC connected state, which may include parameters optimized for energy saving. The technical effect of the ES-CHO configuration may be the ability to quickly offload the UE to a different cell. In an example embodiment, when a serving cell (e.g., a capacity cell) enters one or more corresponding "energy saving modes" (such as "cell shutdown", "network transmit power reduction", "mMIMO transmit antenna element muting", etc.), the UE may use the ES-CHO configuration.

[0103] Using such an ES-CHO configuration may have the technical effect of being able to offload the UE quickly to a different cell (compared to a conventional HO), which is necessary before the cell can enter the new mode, and in turn may allow the cell to achieve greater energy saving potential. This benefit may be particularly important as more dynamic temporal adaptability of power saving modes is anticipated as part of the evolution of 3GPP energy saving solutions (e.g., utilizing Rel. 18 Energy Saving Study (RP-213554)).

[0104] In an example embodiment, the ES-CHO configuration may include one or more candidate target cells. The one or more candidate target cells may include at least one of the following: a cell associated to the coverage layer of the serving cell, or a cell with a frequency layer (e.g., a frequency layer lower than the serving layer) with a priority lower than the frequency layer of the serving cell to enter a given energy-saving mode (e.g., cell shutdown). For example, the target cell assignment may be based on a network shutdown strategy and / or network deployment (e.g., depending on which frequency layers are shut down and the order of shutdown, and which (lower) frequency layers provide coverage when a given (higher) frequency layer is shut down). Each "energy-saving" mode may be associated with a dedicated ES-CHO configuration.

[0105] In an example implementation, the network indicates the UE application that can be used to trigger the ES-CHO configuration. In other words, the serving cell can use any combination of the following options to indicate when the ES-CHO "command" can be executed by the UE (i.e. when the ES-CHO configuration must be applied):

[0106] Implicit indication: The UE may execute the ES-CHO command whenever the serving cell indicates that it is entering / applying an "energy saving" mode associated with a CHO configuration received by the UE. In an example implementation, the network indication of the current "energy saving" mode may be provided via system information.

[0107] Explicit indication: The serving cell may explicitly indicate activation of the ES-CHO configuration, or similarly, may explicitly indicate network offloading (eg, decision to shut down). In an example implementation, these indications may be provided by downlink control information (DCI) / MACCE.

[0108] Time-based indication: The ES-CHO configuration may include a (predicted) time when it should be implemented. This may have the technical effect of giving a cell an opportunity to provide traffic services when the cell has been scheduled to shut down in the near future. In an example embodiment, the time may be a system frame number (SFN) or a high frame number (HFN). Additionally or alternatively, the time may be provided using a (predicted) number of time units in the future (e.g. after receiving the ES-CHO configuration) to when the ES-CHO configuration should be applied.

[0109] In an example implementation, the UE may select a target cell for ES-CHO. When the serving cell indicates that an ES-CHO command associated with a certain energy saving mode must be executed, the UE may determine the target cell based on any of the following options, where the option may be selected based on the capacity / frequency layer decision:

[0110] Option #1 / Default (the target cell may be selected by the UE from the configured cells based on radio measurements (e.g., RRM measurements). The UE may collect RRM measurements of the target cells included in the corresponding ES-CHO configuration, and may select the target cell from the configured target cells for ES-CHO based on the collected RRM measurements. In an example embodiment, the ES-CHO configuration may include radio conditions to be evaluated.

[0111] Option #2 (The target cell may be selected by the UE based on predetermined / previously provided information and / or network configuration). The UE may select a target cell for ES-CHO without performing RRM measurements, but based on: predetermined / stored information of (suitable) target cells among potential target cells provided in the ES-CHO configuration at the UE; and / or predetermined / stored information at the network, as well as the network configuration and selection criteria of the target cell (in an example embodiment, the ES-CHO configuration may contain a list of target cells, each of which may be associated with a given transmission configuration indicator (TCI) state / downlink (DL) beam of the serving cell (based on SSB / CSI-RS) and / or associated with a serving cell RSRP value). The UE may then select a target cell corresponding to its serving beam (TCI state) / RSRP level. Additionally or alternatively, target cell selection may be performed based on the TCI state associated with the serving cell.

[0112] In an example implementation, the selection of the target cell may be optimized using AI / ML. AI / ML may be used to train the capacity / frequency layers so that the UE may perform the selection of the target cell for UE-CHO according to the example implementation described above.

[0113] As described above, machine learning tools, such as neural networks, can be used in an increasing number of applications on different types of devices, such as mobile phones. Neural networks and other machine learning tools can be capable of learning properties from input data in a supervised or unsupervised manner. This learning can be the result of a training algorithm or a meta-neural network that provides a training signal.

[0114] The training algorithm may consist of changing some properties of the neural network so that the output of the neural network is as close as possible to the desired output. Training may include changing the properties of the neural network so as to minimize or reduce the error in the output, also known as the loss. Examples of losses include mean squared error (MSE), cross entropy, etc. In recent deep learning techniques, training is an iterative process, where, in each iteration, the algorithm modifies the weights of the neural network to gradually improve the output of the network, i.e., gradually reduce the loss.

[0115] Training a neural network may include an optimization process, but the ultimate goal of machine learning is different from the typical goal of optimization. In optimization, the goal is to minimize loss. In machine learning, in general, in addition to the goal of optimization, the goal is to let the model learn the properties of the data distribution from a limited training data set. In other words, the training process is additionally used to ensure that the neural network learns to use a limited training data set so that the learning is generalized to data that has not been seen before, that is, data that has not been used to train the model. This additional goal is usually called generalization. In practice, the data can be divided into at least two sets: a training set and a validation set. The training set can be used to train the network, that is, to modify its learnable parameters in order to minimize the loss. The validation set can be used to check the performance of the neural network using data that is not used to minimize the loss (i.e., not part of the training set), where the performance of the neural network using the validation set can be an indication of the final performance of the model. The errors on the training set and the validation set can be monitored during the training process to understand whether the neural network is learning and whether the neural network is learning to generalize. In the case where the network is learning, the training set error should decrease. If the network is not learning, the model may be underfitting. In the case where the network is learning to generalize, the validation set error should decrease and will not be much higher than the training set error. If the training set error is low, but the validation set error is much higher than the training set error, or the validation set error has not decreased, or has even increased, the model may be overfitting. Overfitting may mean that the model has memorized the properties of the training set and performs well only on that set, but does not perform well on sets that were not used to tune its parameters. In other words, the model has not learned to generalize.

[0116] In an example embodiment, the capacity / frequency layer may establish confidence (probability) regarding its knowledge of the overlapping radio environment provided by the coverage / frequency layer and the target cell in the coverage / frequency layer that is suitable for offloading a given UE in the case of a handover. In an example embodiment, the UE RSRP / RSRQ measurements of the strongest neighboring cells and the UE location (precise coordinates, beam information, etc.) can be used to map the location / area / beam in the energy saving (ES) cell with the best target cell in the coverage / frequency layer, where the UE may be offloaded at the next cell change. As another option, the capacity cell may use UE trajectory prediction information calculated / predicted by the capacity cell alone or in conjunction with UE measurements (e.g., UE RSRP / RSRQ measurements of the strongest neighboring cells, UE location information, etc.) to determine the best coverage cell where the UE traffic should be offloaded in the case of a cell shutdown. For example, if the predicted UE trajectory at the capacity cell is able to determine the next (coverage) cell with high probability, this may allow the capacity cell to establish high confidence about the appropriate target cell in the coverage / frequency layer to offload a certain UE in the case of a handover. In an example embodiment, the confidence (probability) value may be updated based on feedback about the selected option corresponding to different UE locations and handover performance, for example, related to the UE performance in terms of bit rate, packet loss rate, latency, etc. of the handover UE. In an example embodiment, if the confidence (probability) is above a threshold, the UE may select a target cell based on predetermined information and / or network configuration. In an example embodiment, if the confidence (probability) is below or equal to a threshold, the UE may select a target cell based on RRM measurements. The threshold may be selected to be a high value, such as 90% confidence.

[0117] In an example embodiment, the target cell may be prepared for / prepared for ES-CHO. In an example embodiment, the target cell preparation may be performed according to conventional procedures and add power saving triggers / causes and (predicted) times when power saving mode will be applied when available. The target gNB may optimize RRM resource reservation based on the received information. Additionally or alternatively, information about CHO handover preparation may be added to the cell deactivation indication sent to the neighboring gNB over the Xn / X2 interface. The information about CHO handover preparation may include a list of currently active UEs to be offloaded to the gNB (i.e., UEs for which the neighboring gNB is configured as a target cell for offloading-based CHO).

[0118] Reference now Figure 5 , shows an example signaling flow diagram according to an example implementation of the present disclosure. The signaling flow diagram includes exchanges between a UE that may be in an RRC_Connected state and a serving gNB.

[0119] At 510, the serving gNB may decide / determine to use ES-CHO during cell shutdown. At 512, the serving gNB may transmit a handover request to the target gNB. The handover request may include an ES-CHO information request including a cell shutdown trigger. This may be viewed as an example that target cell preparation may be performed in accordance with conventional procedures and add a power saving trigger / cause and a (predicted) time when power saving mode will be applied when available. At 514, the target gNB may perform admission control. At 516, the target gNB may transmit a handover request acknowledgment to the serving gNB. At 520, the serving gNB may generate an ES-CHO configuration. The ES-CHO configuration may include information for target cell selection. At 522, the serving gNB may transmit an RRCReconfig message to the UE. The RRCReconfig message may include an ES-CHO configuration, which may include a target gNB for offloading, a target cell for offloading, and / or information for target cell selection. In an example embodiment, the information for target cell selection may be based at least in part on the handover request acknowledgment. At 524, the UE may transmit an RRCReconfigComplete message to the serving gNB. At 526, the UE may store the ES-CHO configuration without applying it. For example, the conditions for applying the ES-CHO configuration may not have occurred yet.

[0120] At 530, the serving gNB may receive / detect an energy saving mode trigger. For example, the energy saving mode trigger may be a cell shutdown trigger. Other types of triggers for energy saving mode may be possible and may occur to one of ordinary skill in the art (e.g., a trigger for "cell shutdown", a trigger for "network transmit power reduction", a trigger for "mMIMO transmit antenna element muting", etc.). At 532, the serving gNB may transmit a deactivation indication to the target gNB. The deactivation indication may include an ES-CHO information request. This may be an example of information about CHO handover preparation being added to a cell deactivation indication sent to a neighboring gNB over an Xn / X2 interface. At 534, the target gNB may perform admission control. At 536, the target gNB may transmit a handover request acknowledgment to the serving gNB. At 540, the serving gNB may transmit a cell shutdown indication to the UE. For example, the indication may be part of system information. In an example embodiment, the indication may be based at least in part on the handover request acknowledgment. At 542, the UE may evaluate the ES-CHO configuration and select a target cell based on the received information. The UE may detach from the serving cell and synchronize with the (selected) target cell. At 550, ES-CHO may be completed. At 560, the target gNB may transmit feedback regarding ES-CHO to the serving gNB.

[0121] Reference now Figure 6, a flow chart of an example network algorithm for updating the confidence level of target cell selection for UE offloading during energy-saving operation of a source node is shown. The source node may have an initial confidence level for the best candidate target cell for a given UE or a group of UEs at a given location, 610. This may be achieved through network configuration or by some initial guesses made by the source unit, for example, by utilizing an ML model available at the source. At the beginning, this guess / confidence may not always be accurate enough, and therefore the source node may update / improve the guess / confidence level by, for example, UE measurements (620) that may determine the strongest candidate target cell for different UEs and UE locations and feedback information (620) from the target node about the actual UE performance after performing a handover. This information may help the source node train its available ML model (630). When the source cell has a good enough confidence level for the best target node for a given UE / a group of UEs at a particular location, the source cell may reduce or turn off RRM measurements for this UE / a group of UEs (i.e., configure the UE to operate under option #2 of implementation #3) (650). In other words, when the new confidence is greater than the threshold (640), the source cell may cause the UE to reduce / stop using RRM measurements and may instead cause the UE / enable the UE to select a target cell based on predetermined information and / or network configuration (650). If the UE has not performed RRM measurements before, the UE may be instructed to continue to omit the execution of RRM measurements.

[0122] In the absence of RRM measurements, the source cell may still determine that its confidence in the best target has decreased, for example through feedback information about the UE performance after performing a handover. The performance degradation (640) may trigger the source node to re-enable RRM measurements for a given UE (or a group of UEs at a given location) by forcing those UEs to operate under option #1 of implementation #3 (660). The RRM measurements may also provide input to the source cell to retrain the source cell's ML model, which determines the best candidate target cell for a given UE or a group of UEs at a particular location. In other words, if the confidence is determined to be below a threshold (640), the source cell may determine that the initial confidence about the target is equal to the new confidence about the target, and may enable the UE / enable the UE to select a target cell based on the RRM measurements.

[0123] Figure 7Potential steps of an example method 700 are shown. The example method 700 may include: receiving one or more handover configurations from a serving cell, wherein the one or more handover configurations include an energy saving conditional handover configuration, wherein at least one of the one or more handover configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection, 710; receiving an indication of activation of an energy saving mode at the serving cell from the serving cell, 720; and selecting a target cell from the one or more candidate target cells based at least in part on the one or more handover configurations and the received indication of activation of the energy saving mode at the serving cell, 730.

[0124] Figure 8 Potential steps of an example method 800 are shown. The example method 800 may include: determining to activate an energy saving mode, 810; generating one or more handover configurations, wherein the one or more handover configurations include an energy saving conditional handover configuration, wherein at least one of the one or more handover configurations includes at least one of an indication of one or more candidate target cells or information for target cell selection, 820; transmitting the one or more handover configurations to a user equipment, 830; starting to activate the energy saving mode, 840; and transmitting an indication of the activation of the energy saving mode to the user equipment, 850.

[0125] According to an example embodiment, a device may include: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least: receive one or more switching configurations from a serving cell, wherein the one or more switching configurations may include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; receive an indication of activation of an energy-saving mode at the serving cell from the serving cell; and select a target cell from the one or more candidate target cells based at least in part on the one or more switching configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0126] The indication that the energy saving mode is activated may be included in a broadcast message.

[0127] The example apparatus may be further configured to: disconnect from the serving cell; and synchronize with the selected target cell.

[0128] The at least one of the one or more handover configurations may further comprise an indication of one or more measurements to be performed.

[0129] The example apparatus may be further configured to: perform at least one measurement of the one or more measurements; and select the target cell based at least in part on a result of the at least one measurement performed.

[0130] Selecting the target cell may include the example device being further configured to: select the target cell based at least in part on one of the following: predetermined information associated with the target cell located at the device, or the information used for target cell selection, the information may include at least one of the following: a transmission configuration indicator state associated with the serving cell or the target cell, a reference signal received power value associated with the serving cell or the target cell, a downlink beam of the serving cell or the target cell, or a selection criterion.

[0131] The example apparatus may be in a radio resource control connected state.

[0132] The indication of activation of the energy saving mode at the serving cell may include an indication of at least one of: cell shutdown, network transmit power reduction, or muting of a multiple-input multiple-output transmit antenna element.

[0133] The indication of the one or more candidate target cells may be based at least in part on one or more network shutdown policies of the serving cell, one or more frequency layers of the serving cell that have been shut down, a shutdown order of the one or more frequency layers of the serving cell that have been shut down, or at least one of frequency layers belonging to the same power saving group as at least one of the one or more frequency layers of the serving cell that have been shut down.

[0134] The example apparatus may also be configured to select an energy saving conditional handover configuration from among the one or more handover configurations based at least in part on the indication of activation of the energy saving mode at the serving cell, wherein selecting the target cell may also be based on the selected energy saving conditional handover configuration.

[0135] The example device may also be configured to: receive an indication of when the one or more switching configurations will be applied, wherein the indication may include at least one of the following: an indication of activation of the energy saving mode at the serving cell; a network offloading indication; an indication of activation of the one or more switching configurations; or an indication of the time to enforce execution of the one or more switching configurations, which may include at least one of a system frame number, a super high frame number, or a number of time units.

[0136] The network offload indication or the indication of activation of the one or more handover configurations may include one of downlink control information or medium access control control elements.

[0137] According to one aspect, an example method may be provided, comprising: receiving, using a user equipment, one or more switching configurations from a serving cell, wherein the one or more switching configurations may include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations may include an indication of one or more candidate target cells or at least one of information for target cell selection; receiving, from the serving cell, an indication of activation of an energy-saving mode at the serving cell; and selecting a target cell from the one or more candidate target cells based at least in part on the one or more switching configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0138] The indication that the energy saving mode is activated may be included in a broadcast message.

[0139] The example method may also include disconnecting the user equipment from the serving cell; and synchronizing the user equipment with the selected target cell.

[0140] The at least one of the one or more handover configurations may further comprise an indication of one or more measurements to be performed.

[0141] The example method may also include performing at least one measurement of the one or more measurements; and selecting the target cell based at least in part on a result of the at least one measurement performed.

[0142] The selecting the target cell may include: selecting the target cell based at least in part on one of the following: predetermined information associated with the target cell located at the user equipment, or the information used for target cell selection, the information may include at least one of the following: a transmission configuration indicator state associated with the serving cell or the target cell, a reference signal received power value associated with the serving cell or the target cell, a downlink beam of the serving cell or the target cell, or a selection criterion.

[0143] The user equipment may be in a radio resource control connected state.

[0144] The indication of activation of the energy saving mode at the serving cell may include an indication of at least one of: cell shutdown, network transmit power reduction, or muting of a multiple-input multiple-output transmit antenna element.

[0145] The indication of the one or more candidate target cells may be based at least in part on one or more network shutdown policies of the serving cell, one or more frequency layers of the serving cell that have been shut down, a shutdown order of the one or more frequency layers of the serving cell that have been shut down, or at least one of frequency layers belonging to the same power saving group as at least one of the one or more frequency layers of the serving cell that have been shut down.

[0146] The example method may also include selecting an energy saving conditional handover configuration of the one or more handover configurations based at least in part on the indication of activation of the energy saving mode at the serving cell, wherein the selecting the target cell may also be based on the selected energy saving conditional handover configuration.

[0147] The example method may also include: receiving an indication of when the one or more switching configurations will be applied, wherein the indication may include at least one of the following: an indication of activation of the energy saving mode at the serving cell; a network offloading indication; an indication of activation of the one or more switching configurations; or an indication of the time to enforce execution of the one or more switching configurations, which may include at least one of a system frame number, a super high frame number, or a number of time units.

[0148] The network offload indication or the indication of activation of the one or more handover configurations may include one of downlink control information or medium access control control elements.

[0149] According to an example embodiment, a device may include: a circuit system configured to perform the following: receiving one or more switching configurations from a serving cell, wherein the one or more switching configurations may include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; receiving an indication of activation of an energy-saving mode at the serving cell from the serving cell; and selecting a target cell from the one or more candidate target cells based at least in part on the one or more switching configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0150] According to an example embodiment, a device may include: a processing circuit system; a memory circuit system including a computer program code, the memory circuit system and the computer program code being configured to, together with the processing circuit system, enable the device to: receive one or more switching configurations from a serving cell, wherein the one or more switching configurations may include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; receive an indication of activation of an energy-saving mode at the serving cell from the serving cell; and select a target cell from the one or more candidate target cells based at least in part on the one or more switching configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0151] As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) hardware circuit implementations only (such as implementations in analog and / or digital circuitry only) and (b) combinations of hardware circuitry and software, such as (where applicable): (i) a combination of analog and / or digital hardware circuitry with software / firmware and (ii) any portion of a hardware processor with software (including a digital signal processor, software, and memory that work together to enable a device (such as a mobile phone or server) to perform various functions); and (c) hardware circuitry and / or processors (such as a microprocessor or a portion of a microprocessor) that require software (e.g., firmware) to operate, but the software may not be present when software is not required for operation. This definition of circuitry applies to all uses of this term in this application (including in any claims). As yet another example, as used in this application, the term circuitry also covers implementations of only hardware circuitry or a processor (or multiple processors) or a portion of a hardware circuitry or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers (for example and where applicable to a particular claim element) a baseband integrated circuit or a processor integrated circuit of a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or networking device.

[0152] According to an example embodiment, a device may include means for performing the following: receiving one or more handover configurations from a serving cell, wherein the one or more handover configurations may include an energy-saving conditional handover configuration, wherein at least one of the one or more handover configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; receiving an indication of activation of an energy-saving mode at the serving cell from the serving cell; and selecting a target cell from the one or more candidate target cells based at least in part on the one or more handover configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0153] The indication that the energy saving mode is activated may be included in a broadcast message.

[0154] The apparatus may be further configured to perform: disconnecting from the serving cell; and synchronizing with the selected target cell.

[0155] The at least one of the one or more handover configurations may further comprise an indication of one or more measurements to be performed.

[0156] The apparatus may be further configured to perform: at least one measurement of the one or more measurements; and select the target cell based at least in part on a result of the at least one measurement performed.

[0157] The device configured to perform selection of the target cell may include a device configured to perform the following: selecting the target cell based at least in part on one of: predetermined information associated with the target cell located at the device; or the information used for target cell selection, which may include a transmission configuration indicator state associated with the serving cell or the target cell, a reference signal received power value associated with the serving cell or the target cell, a downlink beam of the serving cell or the target cell, or at least one of a selection criterion.

[0158] The example apparatus may be in a radio resource control connected state.

[0159] The indication of activation of the energy saving mode at the serving cell may include an indication of at least one of: cell shutdown, network transmit power reduction, or muting of a multiple-input multiple-output transmit antenna element.

[0160] The indication of the one or more candidate target cells may be based at least in part on one or more network shutdown policies of the serving cell, one or more frequency layers of the serving cell that have been shut down, a shutdown order of the one or more frequency layers of the serving cell that have been shut down, or at least one of frequency layers belonging to the same power saving group as at least one of the one or more frequency layers of the serving cell that have been shut down.

[0161] The apparatus may be further configured to perform: selecting an energy saving conditional switching configuration from the one or more switching configurations based at least in part on the indication of activation of the energy saving mode at the serving cell, wherein selecting the target cell may also be based on the selected energy saving conditional switching configuration.

[0162] The device may also be configured to perform: receiving an indication of when the one or more switching configurations will be applied, wherein the indication may include at least one of the following: an indication of activation of the energy saving mode at the serving cell; a network offloading indication; an indication of activation of the one or more switching configurations; or an indication of the time to enforce execution of the one or more switching configurations, which may include at least one of a system frame number, a super high frame number, or a number of time units.

[0163] The network offload indication or the indication of activation of the one or more handover configurations may include one of downlink control information or medium access control control elements.

[0164] According to an example embodiment, a non-transitory computer-readable medium includes program instructions stored thereon, which, when executed by at least one processor, cause the at least one processor to: cause one or more switching configurations to be received from a serving cell, wherein the one or more switching configurations may include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; cause an indication of activation of an energy-saving mode at the serving cell to be received from the serving cell; and select a target cell from the one or more candidate target cells based at least in part on the one or more switching configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0165] The indication that the energy saving mode is activated may be included in a broadcast message.

[0166] The example non-transitory computer-readable medium may be further configured to: cause disconnection from the serving cell; and cause synchronization with the selected target cell.

[0167] The at least one of the one or more handover configurations may further comprise an indication of one or more measurements to be performed.

[0168] The example non-transitory computer-readable medium may be further configured to: cause at least one of the one or more measurements to be performed; and select the target cell based at least in part on a result of the at least one measurement performed.

[0169] Selecting the target cell may include the example non-transitory computer-readable medium being further configured to: select the target cell based at least in part on one of the following: predetermined information associated with the target cell located at the non-transitory computer-readable medium, or the information for target cell selection, which may include at least one of the following: a transmission configuration indicator state associated with the serving cell or the target cell, a reference signal received power value associated with the serving cell or the target cell, a downlink beam of the serving cell or the target cell, or a selection criterion.

[0170] The indication of activation of the energy saving mode at the serving cell may include an indication of at least one of: cell shutdown, network transmit power reduction, or muting of a multiple-input multiple-output transmit antenna element.

[0171] The indication of the one or more candidate target cells may be based at least in part on one or more network shutdown policies of the serving cell, one or more frequency layers of the serving cell that have been shut down, a shutdown order of the one or more frequency layers of the serving cell that have been shut down, or at least one of frequency layers belonging to the same power saving group as at least one of the one or more frequency layers of the serving cell that have been shut down.

[0172] The example non-transitory computer-readable medium may also be configured to select an energy-saving conditional switching configuration from the one or more switching configurations based at least in part on the indication of activation of the energy-saving mode at the serving cell, wherein selecting the target cell may also be based on the selected energy-saving conditional switching configuration.

[0173] The example non-transitory computer-readable medium may also be configured to: cause receipt of an indication of when the one or more switching configurations will be applied, wherein the indication may include at least one of the following: an indication of activation of the energy saving mode at the serving cell; a network offloading indication; an indication of activation of the one or more switching configurations; or an indication of the time at which the one or more switching configurations are enforced, which may include at least one of a system frame number, a super high frame number, or a number of time units.

[0174] The network offload indication or the indication of activation of the one or more handover configurations may include one of downlink control information or medium access control control elements.

[0175] According to another example embodiment, a machine-readable, non-transitory program storage device may be provided, which tangibly embodies a program containing instructions executable by the machine to perform operations, the operations including: causing one or more handover configurations to be received from a serving cell, wherein the one or more handover configurations may include an energy-saving conditional handover configuration, wherein at least one of the one or more handover configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; causing an indication of activation of an energy-saving mode at the serving cell to be received from the serving cell; and selecting a target cell from the one or more candidate target cells based at least in part on the one or more handover configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0176] According to an example embodiment, a device may include: at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code are configured to, together with the at least one processor, cause the device to at least: determine to activate an energy saving mode; generate one or more switching configurations, wherein the one or more switching configurations may include an energy saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; transmit the one or more switching configurations to a user equipment; start activating the energy saving mode; and transmit an indication of the activation of the energy saving mode to the user equipment.

[0177] The indication that the energy saving mode is activated may be included in a broadcast message.

[0178] The example device may also be configured to: transmit a corresponding energy-saving condition switching information request to at least one candidate target cell among the one or more candidate target cells, wherein the corresponding energy-saving condition switching information request may include an energy-saving mode trigger; and receive a switching request response from the at least one candidate target cell.

[0179] The example device may also be configured to: transmit a corresponding cell deactivation indication to at least one of the one or more candidate target cells, wherein the corresponding cell deactivation indication may include at least one of a request for energy-saving conditional switching information, information on switching preparation for conditional switching, or a list of currently active user equipment to be unloaded to a corresponding candidate target cell among the one or more candidate target cells; and receive a switching request response from the one or more candidate target cells.

[0180] The at least one of the one or more handover configurations may further comprise an indication of one or more measurements to be performed.

[0181] The example device may also be configured to: receive an indication of the result of at least one of the one or more measurements from the user equipment; determine a confidence level in selecting a target cell from the one or more candidate target cells for synchronization at the user equipment based at least in part on the indication of the result of the at least one of the one or more measurements; compare the determined confidence level with a threshold; and based on a determination that the determined confidence level is greater than the threshold, instruct the user equipment to: omit execution of the one or more measurements and perform target cell selection based on at least one of: predetermined information associated with the target cell, or the information for target cell selection; and based on a determination that the determined confidence level is less than or equal to the threshold, instruct the user equipment to perform target cell selection based on executing the one or more measurements.

[0182] The information for target cell selection may include at least one of a transmission configuration indicator state associated with the device or the target cell, a reference signal received power value associated with the device or the target cell, a downlink beam or selection criteria of the device or the target cell.

[0183] The energy saving mode may include at least one of cell shutdown, network transmit power reduction, or multi-input multi-output transmit antenna element muting.

[0184] The indication of the one or more candidate target cells may be based at least in part on one or more network shutdown policies, one or more frequency layers that have been shut down, a shutdown order of the one or more frequency layers that have been shut down, or at least one of frequency layers that belong to the same power saving group as at least one of the one or more frequency layers that have been shut down.

[0185] The example device may also be configured to: transmit an indication to the user equipment of when the one or more switching configurations will be applied, wherein the indication may include at least one of the following: an indication of activation of the energy saving mode; a network offloading indication; an indication of activation of the one or more switching configurations; or an indication of the time of enforcing the one or more switching configurations, which may include at least one of a system frame number, a super high frame number, or a number of time units.

[0186] The network offload indication or the indication of activation of the one or more handover configurations may include one of downlink control information or medium access control control elements.

[0187] According to one aspect, an example method may be provided, comprising: determining to activate an energy-saving mode; generating one or more switching configurations, wherein the one or more switching configurations may include an energy-saving conditional switching configuration, wherein at least one of the one or more switching configurations may include an indication of one or more candidate target cells or at least one of information for target cell selection; transmitting the one or more switching configurations to a user device; starting to activate the energy-saving mode; and transmitting an indication of activation of the energy-saving mode to the user device.

[0188] The indication that the energy saving mode is activated may be included in a broadcast message.

[0189] The example method may also include: transmitting a corresponding energy-saving condition switching information request to at least one candidate target cell among the one or more candidate target cells, wherein the corresponding energy-saving condition switching information request may include an energy-saving mode trigger; and receiving a switching request response from the at least one candidate target cell.

[0190] The example method may also include: transmitting a corresponding cell deactivation indication to at least one of the one or more candidate target cells, wherein the corresponding cell deactivation indication may include at least one of a request for energy-saving conditional switching information, information about switching preparation for conditional switching, or a list of currently active user equipment to be unloaded to a corresponding candidate target cell among the one or more candidate target cells; and receiving a switching request response from the one or more candidate target cells.

[0191] The at least one of the one or more handover configurations may further comprise an indication of one or more measurements to be performed.

[0192] The example method may also include: receiving an indication of the result of at least one measurement in the one or more measurements from the user equipment; determining, at least in part based on the indication of the result of the at least one measurement in the one or more measurements, a confidence level in selecting a target cell from the one or more candidate target cells for synchronization at the user equipment; comparing the determined confidence level with a threshold; based on a determination that the determined confidence level is greater than the threshold, instructing the user equipment to omit execution of the one or more measurements and to perform target cell selection based on at least one of predetermined information associated with the target cell or the information used for target cell selection; and based on a determination that the determined confidence level is less than or equal to the threshold, instructing the user equipment to perform target cell selection based on executing the one or more measurements.

[0193] The information for target cell selection may include at least one of a transmission configuration indicator state associated with a base station or a target cell, a reference signal received power value associated with the base station or the target cell, a downlink beam of the base station or the target cell, or a selection criterion.

[0194] The energy saving mode may include at least one of cell shutdown, network transmit power reduction, or multi-input multi-output transmit antenna element muting.

[0195] The indication of the one or more candidate target cells may be based at least in part on one or more network shutdown policies, one or more frequency layers that have been shut down, a shutdown order of the one or more frequency layers that have been shut down, or at least one of frequency layers that belong to the same power saving group as at least one of the one or more frequency layers that have been shut down.

[0196] The example method may also include: transmitting an indication to the user equipment of when the one or more switching configurations will be applied, wherein the indication may include at least one of the following: an indication of activation of the energy saving mode; a network offloading indication; an indication of activation of the one or more switching configurations; or an indication of the time of enforcing the one or more switching configurations, which may include at least one of a system frame number, a super high frame number, or a number of time units.

[0197] The network offload indication or the indication of activation of the one or more handover configurations may include one of downlink control information or medium access control control elements.

[0198] According to an example embodiment, a device may include: a circuit system configured to perform the following: determine to activate an energy saving mode; generate one or more switching configurations, wherein the one or more switching configurations may include an energy saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; transmit the one or more switching configurations to a user device; start activating the energy saving mode; and transmit an indication of the activation of the energy saving mode to the user device.

[0199] According to an example embodiment, a device may include: a processing circuit system; a memory circuit system including a computer program code, the memory circuit system and the computer program code being configured to, together with the processing circuit system, enable the device to: determine to activate an energy saving mode; generate one or more switching configurations, wherein the one or more switching configurations may include an energy saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; transmit the one or more switching configurations to a user equipment; start activating the energy saving mode; and transmit an indication of the activation of the energy saving mode to the user equipment.

[0200] According to an example embodiment, a device may include means for performing the following: determining to activate an energy saving mode; generating one or more switching configurations, wherein the one or more switching configurations may include an energy saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; transmitting the one or more switching configurations to a user equipment; starting to activate the energy saving mode; and transmitting an indication of activation of the energy saving mode to the user equipment.

[0201] The indication that the energy saving mode is activated may be included in a broadcast message.

[0202] The device may also be configured to perform: transmitting a corresponding energy-saving condition switching information request to at least one candidate target cell among the one or more candidate target cells, wherein the corresponding energy-saving condition switching information request may include an energy-saving mode trigger; and receiving a switching request response from the at least one candidate target cell.

[0203] The device may also be configured to perform: transmitting a corresponding cell deactivation indication to at least one of the one or more candidate target cells, wherein the corresponding cell deactivation indication may include at least one of a request for energy-saving conditional switching information, information on switching preparation for conditional switching, or a list of currently active user equipment to be unloaded to a corresponding candidate target cell among the one or more candidate target cells; and receiving a switching request response from the one or more candidate target cells.

[0204] The at least one of the one or more handover configurations may further comprise an indication of one or more measurements to be performed.

[0205] The apparatus may also be configured to perform: receiving an indication of a result of at least one of the one or more measurements from the user equipment; determining, based at least in part on the indication of the result of the at least one of the one or more measurements, a confidence level in selecting a target cell from the one or more candidate target cells for synchronization at the user equipment; comparing the determined confidence level with a threshold; based on a determination that the determined confidence level is greater than the threshold, instructing the user equipment to: omit execution of the one or more measurements and perform target cell selection based on at least one of predetermined information associated with the target cell or the information used for target cell selection; and based on a determination that the determined confidence level is less than or equal to the threshold, instructing the user equipment to perform target cell selection based on executing the one or more measurements.

[0206] The information for target cell selection may include at least one of a transmission configuration indicator state associated with the device or the target cell, a reference signal received power value associated with the device or the target cell, a downlink beam or selection criteria of the device or the target cell.

[0207] The energy saving mode may include at least one of cell shutdown, network transmit power reduction, or multi-input multi-output transmit antenna element muting.

[0208] The indication of the one or more candidate target cells may be based at least in part on one or more network shutdown policies, one or more frequency layers that have been shut down, a shutdown order of the one or more frequency layers that have been shut down, or at least one of frequency layers that belong to the same power saving group as at least one of the one or more frequency layers that have been shut down.

[0209] The apparatus may also be configured to perform: transmitting to the user equipment an indication of when the one or more switching configurations will be applied, wherein the indication may include at least one of: an indication of activation of the energy saving mode; a network offloading indication; an indication of activation of the one or more switching configurations; or an indication of the time of enforcing execution of the one or more switching configurations, which may include at least one of a system frame number, a super high frame number, or a number of time units.

[0210] The network offload indication or the indication of activation of the one or more handover configurations may include one of downlink control information or medium access control control elements.

[0211] According to an example embodiment, a non-transitory computer-readable medium includes program instructions stored thereon, which, when executed by at least one processor, cause the at least one processor to: determine to activate an energy saving mode; generate one or more switching configurations, wherein the one or more switching configurations may include an energy saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; cause the one or more switching configurations to be transmitted to a user equipment; start activating the energy saving mode; and cause an indication of the energy saving mode activation to be transmitted to the user equipment.

[0212] The indication that the energy saving mode is activated may be included in a broadcast message.

[0213] The example non-transitory computer-readable medium may also be configured to: cause a corresponding energy-saving conditional switching information request to be transmitted to at least one candidate target cell among the one or more candidate target cells, wherein the corresponding energy-saving conditional switching information request may include an energy-saving mode trigger; and cause a switching request response to be received from the at least one candidate target cell.

[0214] The example non-transitory computer-readable medium may also be configured to: cause a corresponding cell deactivation indication to be transmitted to at least one of the one or more candidate target cells, wherein the corresponding cell deactivation indication may include at least one of a request for energy-saving conditional switching information, information about switching preparation for conditional switching, or a list of currently active user equipment to be unloaded to a corresponding candidate target cell among the one or more candidate target cells; and cause a switching request response to be received from the one or more candidate target cells.

[0215] The at least one of the one or more handover configurations may further comprise an indication of one or more measurements to be performed.

[0216] The example non-transitory computer-readable medium may also be configured to: cause an indication of a result of at least one of the one or more measurements to be received from the user equipment; determine, at least in part based on the indication of the result of the at least one of the one or more measurements, a confidence level in selecting a target cell from the one or more candidate target cells for synchronization at the user equipment; compare the determined confidence level with a threshold; based on a determination that the determined confidence level is greater than the threshold, cause an indication to the user equipment to: omit execution of the one or more measurements, and perform target cell selection based on at least one of predetermined information associated with the target cell or the information used for target cell selection; and based on a determination that the determined confidence level is less than or equal to the threshold, cause an indication to the user equipment to perform target cell selection based on executing the one or more measurements.

[0217] The information for target cell selection may include at least one of a transmission configuration indicator state associated with a base station or a target cell, a reference signal received power value associated with the base station or the target cell, a downlink beam of the base station or the target cell, or a selection criterion.

[0218] The energy saving mode may include at least one of cell shutdown, network transmit power reduction, or multi-input multi-output transmit antenna element muting.

[0219] The indication of the one or more candidate target cells may be based at least in part on one or more network shutdown policies, one or more frequency layers that have been shut down, a shutdown order of the one or more frequency layers that have been shut down, or at least one of frequency layers that belong to the same power saving group as at least one of the one or more frequency layers that have been shut down.

[0220] The example non-transitory computer-readable medium may also be configured to: cause an indication to be transmitted to the user device of when the one or more switching configurations will be applied, wherein the indication may include at least one of the following: an indication of activation of the energy saving mode; a network offloading indication; an indication of activation of the one or more switching configurations; or an indication of the time to enforce execution of the one or more switching configurations, which may include at least one of a system frame number, a super high frame number, or a number of time units.

[0221] The network offload indication or the indication of activation of the one or more handover configurations may include one of downlink control information or medium access control control elements.

[0222] According to another example embodiment, a machine-readable, non-transitory program storage device may be provided, which tangibly embodies a program containing instructions executable by the machine to perform operations, the operations including: determining to activate an energy saving mode; generating one or more switching configurations, wherein the one or more switching configurations may include an energy saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; causing the one or more switching configurations to be transmitted to a user device; starting to activate the energy saving mode; and causing an indication of the energy saving mode activation to be transmitted to the user device.

[0223] According to another example embodiment, a computer program may include instructions stored thereon for performing at least the following: receiving one or more handover configurations from a serving cell, wherein the one or more handover configurations may include an energy-saving conditional handover configuration, wherein at least one of the one or more handover configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; receiving an indication of activation of an energy-saving mode at the serving cell from the serving cell; and selecting a target cell from the one or more candidate target cells based at least in part on the one or more handover configurations and the received indication of activation of the energy-saving mode at the serving cell.

[0224] According to another example embodiment, a computer program may include instructions stored thereon for performing at least the following: determining to activate an energy saving mode; generating one or more switching configurations, wherein the one or more switching configurations may include an energy saving conditional switching configuration, wherein at least one of the one or more switching configurations may include at least one of an indication of one or more candidate target cells or information for target cell selection; transmitting the one or more switching configurations to a user equipment; starting to activate the energy saving mode; and transmitting an indication of activation of the energy saving mode to the user equipment.

[0225] It should be understood that the above description is illustrative only. Various alternatives and modifications may occur to those skilled in the art. For example, the features described in the dependent claims may be combined with each other in any suitable combination. In addition, features from the different embodiments described above may be selectively combined into new embodiments. Therefore, this specification is intended to cover all such alternatives, modifications and variations that fall within the scope of the appended claims.

Claims

1. A device comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least: Receiving one or more handover configurations from a serving cell, wherein the one or more handover configurations include an energy saving condition handover configuration, wherein at least one handover configuration of the one or more handover configurations includes at least one of the following: an indication of one or more candidate target cells, or Information used for target cell selection; receiving, from the serving cell, an indication that an energy saving mode is activated at the serving cell; and A target cell is selected from the one or more candidate target cells based at least in part on the one or more handover configurations and the received indication of the energy saving mode activation at the serving cell.

2. The apparatus of claim 1, wherein the indication that the energy saving mode is activated is included in a broadcast message.

3. The apparatus of claim 1 or 2, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: disconnecting from the serving cell; and and synchronized with the selected target cell.

4. The apparatus of any one of claims 1 to 3, wherein the at least one of the one or more handover configurations further comprises an indication of one or more measurements to be performed.

5. The apparatus of claim 4, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: performing at least one of the one or more measurements; and The target cell is selected based at least in part on a result of the at least one measurement performed.

6. The apparatus of any one of claims 1 to 4, wherein selecting the target cell comprises the at least one memory and the computer program code being configured to, together with the at least one processor, cause the apparatus to: The target cell is selected based at least in part on one of: predetermined information associated with the target cell located at the device, or The information used for target cell selection includes at least one of the following: a transmission configuration indicator state associated with the serving cell or the target cell, a reference signal received power value associated with the serving cell or the target cell, The downlink beam of the serving cell or the target cell, or Select Standard.

7. The apparatus according to any one of claims 1 to 6, wherein the apparatus is in a radio resource control connected state.

8. The apparatus according to any one of claims 1 to 7, wherein the indication of activation of the energy saving mode at the serving cell comprises an indication of at least one of: The community is shut down. The network transmit power is reduced, or Multiple-input and multiple-output transmit antenna elements are muted.

9. The apparatus of any one of claims 1 to 8, wherein the indication of the one or more candidate target cells is based at least in part on at least one of: one or more network shutdown policies of the serving cell, One or more frequency layers of the serving cell that have been turned off, the order in which the one or more frequency layers of the serving cell that have been powered off are turned off, or At least one frequency layer among the one or more frequency layers of the serving cell that have been shut down belongs to a frequency layer of the same power saving group.

10. The apparatus of any one of claims 1 to 9, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: An energy saving conditional handover configuration of the one or more handover configurations is selected based at least in part on the indication of activation of the energy saving mode at the serving cell, wherein selecting the target cell is further based on the selected energy saving conditional handover configuration.

11. The apparatus of any one of claims 1 to 10, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: Receiving an indication of when the one or more switching configurations are to be applied, wherein the indication comprises at least one of: said indication of activation of said energy saving mode at said serving cell, Network uninstall instructions, an indication that the one or more handover configurations are activated, or An indication of a time to enforce the one or more switching configurations, comprising at least one of: System frame number, Very high frame number, or The number of time units.

12. The apparatus of claim 11, wherein the network offload indication or the indication of activation of the one or more handover configurations comprises one of: Downlink control information, or Media access control element.

13. A method comprising: Receiving, by a user equipment, one or more handover configurations from a serving cell, wherein the one or more handover configurations include an energy-saving conditional handover configuration, wherein at least one handover configuration of the one or more handover configurations includes at least one of the following: an indication of one or more candidate target cells, or Information used for target cell selection; receiving, from the serving cell, an indication of activation of an energy saving mode at the serving cell; as well as A target cell is selected from the one or more candidate target cells based at least in part on the one or more handover configurations and the received indication of the energy saving mode activation at the serving cell.

14. The method of claim 13, wherein the indication of the energy saving mode activation is included in a broadcast message.

15. The method of claim 13 or 14, further comprising: Disconnecting the user equipment from the serving cell; as well as The user equipment is synchronized with the selected target cell.

16. The method of any one of claims 13 to 15, wherein the at least one of the one or more handover configurations further comprises an indication of one or more measurements to be performed.

17. The method of claim 16, further comprising: performing at least one of the one or more measurements; as well as The target cell is selected based at least in part on a result of the at least one measurement performed.

18. The method according to any one of claims 13 to 16, wherein the selecting the target cell comprises: The target cell is selected based at least in part on one of: predetermined information associated with the target cell located at the user equipment, or The information used for target cell selection includes at least one of the following: a transmission configuration indicator state associated with the serving cell or the target cell, a reference signal received power value associated with the serving cell or the target cell, a downlink beam of the serving cell or the target cell, or Select Standard.

19. The method according to any one of claims 13 to 18, wherein the user equipment is in a radio resource control connected state.

20. The method of any one of claims 13 to 19, wherein the indication of activation of the energy saving mode at the serving cell comprises an indication of at least one of: The community is shut down. The network transmit power is reduced, or Multiple-input and multiple-output transmit antenna elements are muted.

21. The method of any one of claims 13 to 20, wherein the indication of the one or more candidate target cells is based at least in part on at least one of: one or more network shutdown policies of the serving cell, One or more frequency layers of the serving cell that have been turned off, the order in which the one or more frequency layers of the serving cell that have been powered off are turned off, or At least one frequency layer among the one or more frequency layers of the serving cell that have been shut down belongs to a frequency layer of the same power saving group.

22. The method of any one of claims 13 to 21, further comprising: An energy saving conditional handover configuration of the one or more handover configurations is selected based at least in part on the indication of activation of the energy saving mode at the serving cell, wherein the selecting the target cell is further based on the selected energy saving conditional handover configuration.

23. The method of any one of claims 13 to 22, further comprising: Receiving an indication of when the one or more switching configurations are to be applied, wherein the indication comprises at least one of: said indication of activation of said energy saving mode at said serving cell, Network uninstall instructions, an indication that the one or more handover configurations are activated, or An indication of a time to enforce the one or more switching configurations, comprising at least one of: System frame number, Very high frame number, or The number of time units.

24. The method of claim 23, wherein the network offload indication or the indication of activation of the one or more handover configurations comprises one of: Downlink control information, or Media access control element.

25. An apparatus comprising means for performing: Receiving one or more handover configurations from a serving cell, wherein the one or more handover configurations include an energy saving condition handover configuration, wherein at least one handover configuration of the one or more handover configurations includes at least one of the following: an indication of one or more candidate target cells, or Information used for target cell selection; receiving, from the serving cell, an indication of activation of an energy saving mode at the serving cell; and A target cell is selected from the one or more candidate target cells based at least in part on the one or more handover configurations and the received indication of the energy saving mode activation at the serving cell.

26. The apparatus of claim 25, wherein the indication of the energy saving mode activation is included in a broadcast message.

27. The apparatus of claim 25 or 26, wherein the device is further configured to perform: disconnecting from the serving cell; and and synchronized with the selected target cell.

28. The apparatus of any one of claims 25 to 27, wherein the at least one of the one or more handover configurations further comprises an indication of one or more measurements to be performed.

29. The apparatus of claim 28, wherein the device is further configured to perform: at least one measurement of the one or more measurements; and The target cell is selected based at least in part on a result of the at least one measurement performed.

30. The apparatus of any one of claims 25 to 28, wherein the means configured to perform selecting the target cell comprises means configured to: The target cell is selected based at least in part on one of: predetermined information associated with the target cell located at the device, or The information used for target cell selection includes at least one of the following: a transmission configuration indicator state associated with the serving cell or the target cell, a reference signal received power value associated with the serving cell or the target cell, a downlink beam of the serving cell or the target cell, or Select Standard.

31. The apparatus of any one of claims 25 to 30, wherein the apparatus is in a radio resource control connected state.

32. The apparatus of any one of claims 25 to 31, wherein the indication of activation of the energy saving mode at the serving cell comprises an indication of at least one of: The community is shut down. The network transmit power is reduced, or Multiple-input and multiple-output transmit antenna elements are muted.

33. The apparatus of any one of claims 25 to 32, wherein the indication of the one or more candidate target cells is based at least in part on at least one of: one or more network shutdown policies of the serving cell, One or more frequency layers of the serving cell that have been turned off, the order in which the one or more frequency layers of the serving cell that have been powered off are turned off, or At least one frequency layer among the one or more frequency layers of the serving cell that have been shut down belongs to a frequency layer of the same power saving group.

34. The apparatus of any one of claims 25 to 33, wherein the device is further configured to perform: An energy saving conditional handover configuration of the one or more handover configurations is selected based at least in part on the indication of activation of the energy saving mode at the serving cell, wherein selecting the target cell is further based on the selected energy saving conditional handover configuration.

35. The apparatus of any one of claims 25 to 34, wherein the device is further configured to perform: Receiving an indication of when the one or more switching configurations are to be applied, wherein the indication comprises at least one of: said indication of activation of said energy saving mode at said serving cell, Network uninstall instructions, an indication that the one or more handover configurations are activated, or An indication of a time to enforce the one or more switching configurations, comprising at least one of: System frame number, Very high frame number, or The number of time units.

36. The apparatus of claim 35, wherein the network offload indication or the indication of activation of the one or more handover configurations comprises one of: Downlink control information, or Media access control element.

37. A non-transitory computer readable medium comprising program instructions stored thereon, which when executed by at least one processor cause the at least one processor to: causing one or more handover configurations to be received from a serving cell, wherein the one or more handover configurations include an energy saving conditional handover configuration, wherein at least one handover configuration of the one or more handover configurations includes at least one of the following: an indication of one or more candidate target cells, or Information used for target cell selection; causing receipt from the serving cell of an indication that an energy saving mode at the serving cell is activated; and A target cell is selected from the one or more candidate target cells based at least in part on the one or more handover configurations and the received indication of the energy saving mode activation at the serving cell.

38. An apparatus comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least: Confirm activation of energy saving mode; Generate one or more switching configurations, wherein the one or more switching configurations include a power saving condition switching configuration, wherein at least one switching configuration of the one or more switching configurations includes at least one of the following: an indication of one or more candidate target cells, or Information used for target cell selection; transmitting the one or more switching configurations to a user equipment; Beginning to activate the energy saving mode; and An indication of activation of the energy saving mode is transmitted to the user equipment.

39. The apparatus of claim 38, wherein the indication of the energy saving mode activation is included in a broadcast message.

40. The apparatus of claim 38 or 39, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: transmitting a corresponding energy-saving condition switching information request to at least one candidate target cell among the one or more candidate target cells, wherein the corresponding energy-saving condition switching information request includes an energy-saving mode trigger; and A handover request acknowledgement is received from the at least one candidate target cell.

41. The apparatus of any one of claims 38 to 40, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: transmitting a corresponding cell deactivation indication to at least one candidate target cell among the one or more candidate target cells, wherein the corresponding cell deactivation indication comprises at least one of the following: Energy saving condition switching information request, Information about the switch preparation for a conditional switch, or a list of currently active user equipments to be offloaded to respective ones of the one or more candidate target cells; and A handover request acknowledgement is received from the one or more candidate target cells.

42. The apparatus of any one of claims 38 to 41, wherein the at least one of the one or more handover configurations further comprises an indication of one or more measurements to be performed.

43. The apparatus of claim 42, wherein the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to: receiving, from the user equipment, an indication of a result of at least one of the one or more measurements; determining, based at least in part on the indication of the result of the at least one of the one or more measurements, a confidence level with which a target cell of the one or more candidate target cells will be selected for synchronization at the user equipment; comparing the determined confidence level to a threshold; Based on the determination that the determined confidence level is greater than the threshold, instructing the user equipment to omit the execution of the one or more measurements and to perform target cell selection based on at least one of the following: predetermined information associated with the target cell, or The information used for target cell selection; and Based on a determination that the determined confidence level is less than or equal to the threshold, instructing the user equipment to perform target cell selection based on performing the one or more measurements.

44. The apparatus of any one of claims 38 to 43, wherein the information for target cell selection comprises at least one of: a transmission configuration indicator state associated with the device or target cell, a reference signal received power value associated with the device or the target cell, a downlink beam of the device or the target cell, or Select Standard.

45. The apparatus of any one of claims 38 to 44, wherein the energy saving mode comprises at least one of: The community is shut down. The network transmit power is reduced, or Multiple-input and multiple-output transmit antenna elements are muted.

46. ​​The apparatus of any one of claims 38 to 45, wherein the indication of the one or more candidate target cells is based at least in part on at least one of: One or more network shutdown policies, One or more frequency layers have been shut down, the order in which the one or more frequency layers that have been shut down are shut down, or A frequency layer that belongs to the same power saving group as at least one of the one or more frequency layers that have been shut down.

47. The apparatus of any one of claims 38 to 46, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to: transmitting to the user equipment an indication of when the one or more handover configurations are to be applied, wherein the indication comprises at least one of: said indication that said energy saving mode is activated, Network uninstall instructions, an indication that the one or more handover configurations are activated, or An indication of a time to enforce the one or more switching configurations, comprising at least one of: System frame number, Very high frame number, or The number of time units.

48. The apparatus of claim 47, wherein the network offload indication or the indication of activation of the one or more handover configurations comprises one of: Downlink control information, or Media access control element.

49. A method comprising: Confirm activation of energy saving mode; Generate one or more switching configurations, wherein the one or more switching configurations include a power saving condition switching configuration, wherein at least one switching configuration of the one or more switching configurations includes at least one of the following: an indication of one or more candidate target cells, or Information used for target cell selection; transmitting the one or more switching configurations to a user equipment; Beginning to activate the energy saving mode; and An indication of activation of the energy saving mode is transmitted to the user equipment.

50. An apparatus comprising means for performing: Confirm activation of energy saving mode; Generate one or more switching configurations, wherein the one or more switching configurations include a power saving condition switching configuration, wherein at least one switching configuration of the one or more switching configurations includes at least one of the following: an indication of one or more candidate target cells, or Information used for target cell selection; transmitting the one or more switching configurations to a user equipment; Begin activation of the energy saving mode; and An indication of activation of the energy saving mode is transmitted to the user equipment.

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