CHO enhancements based on source and target cells in NES mode

Abstract

Methods and apparatus are provided for conditional handover (CHO) based on a source cell and a target cell in a network energy saving (NES) mode. A user equipment (UE) measures a reference signal from a candidate target cell and reports a corresponding measurement to a source cell. The UE receives a CHO configuration and an NES CHO configuration. During a handover execution phase of the CHO procedure, the UE evaluates a CHO condition based on the CHO configuration. In response to detecting that the source cell is in the NES mode, the UE switches from evaluating the CHO condition based on the CHO configuration to performing the NES CHO evaluation based on the NES CHO configuration. The UE selects a target cell from the candidate target cells based on the NES CHO evaluation and completes handover to the target cell.

Description

Technical Field

[0001] The present application generally relates to wireless communication systems, including systems with conditional handover (CHO) between cells. Background Art

[0002] Wireless mobile communication technologies use various standards and protocols to transmit data between base stations and wireless communication devices. Wireless communication system standards and protocols may include, for example, the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) (e.g., 4G), 3GPP New Radio (NR) (e.g., 5G), and the IEEE 802.11 standard for wireless local area networks (WLANs), commonly referred to within industry organizations as WLANs. ).

[0003] As envisioned by 3GPP, different wireless communication system standards and protocols may use various radio access networks (RANs) to facilitate communication between base stations of the RAN (which may also sometimes be referred to as RAN nodes, network nodes, or simply nodes) and wireless communication devices, referred to as user equipment (UE). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN can use one or more radio access technologies (RATs) to perform communications between base stations and UEs. For example, GERAN implements GSM and / or EDGE RATs, UTRAN implements Universal Mobile Telecommunications System (UMTS) RATs or other 3GPP RATs, E-UTRAN implements LTE RATs (sometimes referred to herein as LTE), and NG-RAN implements NR RATs (sometimes referred to herein as 5G RATs, 5G NR RATs, or simply NR). In some deployments, E-UTRAN may also implement NR RATs. In some deployments, NG-RAN may also implement LTE RATs.

[0005] The base stations used by the RAN may correspond to the RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (often also denoted as an evolved Node B, enhanced Node B, eNodeB, or eNB). An example of an NG-RAN base station is a Next Generation Node B (sometimes also referred to as a gNode B or gNB).

[0006] The RAN provides communication services with external entities through its connection to the Core Network (CN). For example, E-UTRAN may utilize the Evolved Packet Core (EPC), while NG-RAN may utilize the 5G Core Network (5GC).

[0007] The frequency bands of 5G NR can be divided into two or more different frequency ranges. For example, frequency range 1 (FR1) may include frequency bands operating at frequencies below 6 GHz, some of which may be used by previous standards and may potentially be expanded to cover new spectrum products from 410 MHz to 7125 MHz. Frequency range 2 (FR2) may include frequency bands from 24.25 GHz to 52.6 GHz. Note that in some systems, FR2 may also include frequency bands from 52.6 GHz to 71 GHz (or higher). The frequency bands in the millimeter wave (mmWave) range of FR2 may have smaller coverage than the frequency bands in FR1 but potentially higher available bandwidth. The skilled person will recognize that these frequency ranges, provided by way of example, may change over time or from region to region. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To easily identify the discussion of any particular element or action, the most significant digit(s) in a reference number refers to the drawing number that first introduces that element.

[0009] Figure 1A and Figure 1B Together, a flow chart illustrating conditional handover that may be used in some wireless communication systems is illustrated.

[0010] Figure 2 is a flow chart of an example NES CHO process, according to certain embodiments.

[0011] Figure 3 A flow chart illustrating a method for a UE to perform CHO in a wireless network including a cell in NES mode according to one embodiment is shown.

[0012] Figure 4 A flow chart illustrating a method in which a base station configured as a source cell performs CHO in a wireless network including a cell in NES mode according to one embodiment is illustrated.

[0013] Figure 5 An example architecture of a wireless communication system according to embodiments disclosed herein is illustrated.

[0014] Figure 6 A system for performing signaling between a wireless device and a network device according to embodiments disclosed herein is illustrated. DETAILED DESCRIPTION

[0015] Various embodiments are described with respect to a UE. However, reference to a UE is provided for illustrative purposes only. The example embodiments may be used with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Therefore, a UE as described herein is intended to represent any suitable electronic component.

[0016] In certain wireless systems, it may be useful to implement CHO enhancements when the source or target cell is in network energy saving (NES) mode. Possible techniques on both the gNB and UE sides can be utilized to improve network energy savings in both base station transmission and reception. For example, in an effort to dynamically and / or semi-statically achieve more efficient operation and to achieve finer-grained adaptation of transmission and / or reception, one or more network energy saving techniques in the time, frequency, spatial, and power domains may be used, along with potential support / feedback from the UE and potential UE assistance information and / or information exchange / coordination across network interfaces.

[0017] NES techniques may include, for example, synchronization signal block (SSB)-free secondary cell (SCell) operation for inter-band carrier aggregation (CA) for FR1 and co-located cells, use of cell discontinuous transmission (DTX) and / or discontinuous reception (DRX), use of spatial element (e.g., antenna port, active transceiver chain, etc.) adaptation, use of physical downlink shared channel (PDSCH) transmission power adaptation, use of paging enhancement, and, if necessary, preventing legacy UEs from camping on cells employing new NES techniques. Other techniques are not excluded and may prioritize, for example, idle / empty and low / medium load scenarios. In addition, different loads between carriers and adjacent cells may be allowed.

[0018] Conditional switching

[0019] Conditional Handover (CHO) is a feature introduced to improve mobility robustness. In CHO, the UE may be configured with a handover command and associated conditions to be monitored. When the associated condition becomes true, the UE may execute the stored "handover" command. Event conditions may include, for example, when a neighboring cell becomes better than a special cell (SpCell) by a certain offset (i.e., an A3 event condition), or when the SpCell becomes worse than a first threshold and the neighboring cell becomes better than a second threshold (i.e., an A5 event condition). The SpCell is the primary serving cell of a master cell group (MCG) or a secondary cell group (SCG), and the offset may be positive or negative. When more than one candidate target cell meets the condition, it may depend on the UE specific implementation to determine which cell can perform the handover (HO). In some wireless communication systems (e.g., 3GPP Release 17), new conditional trigger conditions related to location and time may be defined to help enhance CHO for NR non-terrestrial networks (NTNs).

[0020] Figure 1A and Figure 1B A flowchart 100 illustrating conditional handover that can be used in some wireless communication systems is provided. Flowchart 100 illustrates a wireless communication system that includes a UE 102, a source gNB 104, a target gNB 106, other potential target gNBs 108, an access and mobility management function (AMF) 110, and one or more user plane functions (UFPs) 112. It can be seen that flowchart 100 corresponds to the intra-AMF / UPF scenario.

[0021] like Figure 1A As shown, flowchart 100 begins with a handover preparation phase 114. Currently, as shown, user data 116 is transmitted between UE 102 and source gNB 104, and between source gNB 104 and UFP 112. AMF 110 provides mobility control information 118 to source gNB 104. Then, during measurement control and reporting 120, source gNB 104 configures measurements at UE 102, and UE 102 performs the measurements and reports the measurement results to source gNB 104. Based on the receipt of the measurement reports, source gNB 104 makes a CHO decision 122. Based on the CHO decision 122, source gNB 104 sends a handover request 124 to other gNBs (in flowchart 100, both target gNB 106, which will ultimately be selected as the target for the handover, and other potential target gNBs 108 are shown as receiving the handover request 124).

[0022] The other gNBs (e.g., target gNB 106 and other potential target gNBs 108) each perform admission control 126 and reply to the source gNB 104 with a handover request acknowledgment 128, including the configuration of any CHO candidate cells at that gNB.

[0023] Figure 1B Continue with the above Figure 1A Flowchart 100 is discussed. Source gNB 104 sends a radio resource control (RRC) reconfiguration message 130 with a configuration for a CHO candidate cell to UE 102. UE 102 sends an RRC reconfiguration complete message 132 to source gNB 104.

[0024] The flowchart 100 then enters a handover execution phase 134. The UE 102 evaluates 136 the CHO condition. Additionally, in some embodiments (e.g., where early data forwarding is used), the target gNB 106 sends an early status transfer message 138 to other potential target gNBs 108.

[0025] UE 102 then detaches from old cell 140 and synchronizes to a new cell (e.g., on target gNB 106). As part of this process, the UE evaluates the conditions on the candidate cells and determines that the new cell (on target gNB 106) meets these conditions and therefore will be handed over to that cell. The configuration for the new cell is then applied at the UE.

[0026] Additionally, user data 142 is transferred between the UFP 112 and the target gNB 106 and / or other potential target gNBs 108 via the source gNB 104. Once the UE 102 becomes associated with the new cell on the source gNB 104 (and the UE 102 may send an accompanying RRC Reconfiguration Complete message to the target gNB 106), a CHO Handover Complete 144 occurs.

[0027] The flowchart 100 then proceeds to the Handover Completion phase 146. First, the target gNB 106 sends a Handover Success message 148 to the source gNB 104. Then, the source gNB 104 sends a Sequence Number (SN) Status Transfer 150 to the target gNB 106. User data 152 is transferred between the UFP 112 and the target gNB 106 via the source gNB 104. Finally, the source gNB 104 may send a Handover Cancel message 154 to the target gNB 106 and / or other potential target gNBs 108.

[0028] During handover in NES mode, the CHO framework can be enhanced by evaluating CHO conditions based on the NES mode of the source or target cell, thereby handing over the UE faster. However, the system has not yet defined how to indicate to the UE the trigger for evaluating such CHO conditions based on the NES mode. When triggering movement from the source cell, the NES mode of the target cell can also be considered, for example, to prevent the UE from selecting a cell operating in NES mode when any other cell is available.

[0029] In some wireless systems, the NES CHO enhancement solution may be based only on the target cell NES mode. For example, in a CHO configuration message (e.g., CHO-Config), the base station (e.g., gNB) may include a different priority value for each candidate target cell. The priority value may be dedicated to each candidate target cell or may be shared by a group of candidate target cells. The base station may determine how to set the priority value. The intention or reason for the base station to select the priority value may be transparent to the UE. In addition, different priority values ​​may be configured for different cell types. For example, the priority value may be based on whether the cell is an NES cell, an NTN cell, a TN cell, a mobile cell, a small cell, etc. For HO execution (e.g., see Figure 1B In the handover execution phase 134 of the CHO procedure shown, if more than one candidate target cell meets the CHO conditions, the UE may select the cell with the highest configured priority value or the highest default priority value to perform HO.

[0030] In addition, or in other wireless systems, the NES CHO enhancement solution includes triggering group HO by UE group common Layer 1 and / or Layer 2 (L1 / L2) signaling sent by the source cell. For example, only one target cell may be pre-configured, and the receipt of UE group common L1 / L2 signaling may be a condition for executing HO. When the source cell enters NES mode, the source cell may send UE group common signaling to trigger HO execution.

[0031] Certain embodiments disclosed herein provide a CHO enhancement solution based on the NES mode of both the source cell and the target cell. For example, after receiving a CHO command, the UE may begin evaluating existing or traditional CHO conditions (e.g., A3 or A5 event conditions) and may switch to NES-specific CHO conditions upon detecting a source cell in NES mode. As an alternative (or in addition) to explicit UE group common L1 / L2 signaling, other implicit indications of source cell NES mode changes may be used. As discussed herein, the NES mode of the target cell may also be considered in the NES-specific CHO condition evaluation.

[0032] In certain embodiments, after detecting that the source cell is in NES mode, the UE uses different alternative threshold offsets for CHO condition evaluation. Upon detecting that the source cell has entered NES mode, a threshold offset may be applied. The threshold offset may be configured to relax the conditions for performing a HO and expedite the completion of a CHO. For CHO condition evaluation of a target cell in NES mode, different threshold offsets may be applied to prevent the UE from selecting a cell operating in NES mode when any other cell is available.

[0033] In another embodiment, after detecting that the source cell is in NES mode, the UE switches to another configured CHO condition (e.g., A4 event condition). The A4 event condition is based on determining that the reference signal received power (RSRP) or reference signal received quality (RSRQ) of the neighboring cell or target cell is better than a threshold. Therefore, the UE can only consider the radio conditions of the neighboring cell, regardless of the radio conditions of the source cell.

[0034] In certain embodiments, if both a normal cell (ie, a cell not in NES mode) and an NES cell (ie, a cell in NES mode) satisfy NES-specific CHO conditions, the UE may prioritize the normal cell for HO execution.

[0035] Example NES CHO Configuration

[0036] In certain embodiments, a base station (e.g., a gNB) includes NES configuration parameters for each candidate target cell in a CHO configuration message (e.g., CHO-Config) or an NES configuration message (e.g., NES-CHO-Config) sent to a UE. For each candidate target cell, the NES configuration parameters include an indication of whether the candidate target cell is in NES mode, an optional priority value (e.g., values ​​0-7), and / or optional different CHO evaluation thresholds depending on whether the target cell is in NES mode (i.e., different thresholds are used for normal cell operation and cell operation in NES mode).

[0037] The configured priority value may be specific to each candidate target cell or may be common to a group of candidate target cells. How the priority value is set may be determined by the gNB. The intent or reason for the base station's selection of the priority value may be transparent to the UE. In some embodiments, different priority values ​​are configured for target cells based on which NES technology is used. For example, the gNB may configure a priority value of five (5) for a target cell that applies cell DTX / DRX, and a priority value of six (6) for a target cell that applies adaptive PDSCH transmit power.

[0038] In certain embodiments, the NES configuration parameters include a CHO condition evaluation threshold offset. The threshold offset can be an RSRP / RSRQ offset configured in a traditional CHO condition (e.g., an A3 or A5 event). The threshold offset can be a common offset or an NES cell-specific offset. For example, in one embodiment, a common threshold offset is provided for all candidate target cells. In another embodiment, a threshold offset is provided for candidate target cells indicated as normal cells, and another threshold offset is provided for candidate target cells indicated as cells in NES mode.

[0039] In some embodiments, the NES configuration parameters include one or more NES CHO conditions that are not used until a change in NES mode of the source cell is detected. For example, an A4 event condition may be indicated, where the RSRP / RSRQ of the target cell is determined to be better than a threshold. Thus, the UE may only consider the radio conditions of the neighboring cells, regardless of the radio conditions of the source cell after the source cell enters NES mode.

[0040] In some embodiments, the NES configuration parameter indicates that a new S-measure may be used when a change in the NES mode of the source cell is detected. Therefore, the UE may start neighbor cell measurements earlier when the current serving cell enters NES mode.

[0041] Example NES CHO Process

[0042] Figure 2 is a flow chart of an example NES CHO process 200 according to certain embodiments. In the illustrated example, the wireless communication system includes a UE 202, a source cell 204 (shown as an S-gNB), a first target cell 206 (shown as t-gNB1), and a second target cell 208 (shown as t-gNB2). However, those skilled in the art will appreciate from the disclosure herein that a wireless network may include fewer or more elements, including one or more additional candidate target cells.

[0043] Figure 2 The CHO preparation stage 210 shown may correspond to Figure 1A and Figure 1B The handover preparation phase 114 is shown. However, Figure 2In the illustrated example, a CHO configuration list 212 (shown as a CHO-Config list) includes both a CHO configuration 214 (shown as CHO-Config (legacy)) and an NES CHO configuration 216 (shown as NES-CHO-Config). The CHO configuration 214 may include a CHO configuration identifier (CHO config ID), one or more CHO conditions with corresponding measurement identifiers (Meas IDs), a CHO RRC configuration (e.g., for each candidate target cell, including a target cell configuration and a priority value), and a list of cell identifiers (IDs) of NES cells. The NES CHO configuration 216 may include one or more NES CHO conditions and corresponding Meas IDs, as well as one or more NES CHO threshold offsets. The source cell 204 may configure the UE 202 with both the CHO configuration 214 and the NES CHO configuration 216.

[0044] In addition, or in another embodiment, the source cell 204 can generate one or more report configuration messages 218 (e.g., ReportConfigNR information elements (IEs)) from the CHO configuration 214 to specify criteria for triggering NR measurement reporting events (e.g., CHO-TriggerConfig specifying legacy CHO event A3 and / or CHO event A5). The source cell 204 can also generate one or more report configuration messages 220 (e.g., ReportConfigNR IEs) from the NESCHO configuration 216 to specify criteria for triggering NR measurement reporting events (e.g., CHO-TriggerConfig specifying NES CHO event A4).

[0045] The source cell 204 may send a CHO command and / or a CHO configuration 214 and an NES CHO configuration 216 to the UE 202 using an RRC reconfiguration message (RRCReconfiguration). In response, the UE 202 sends an RRC reconfiguration complete message (RRCReconfigurationComplete) to the source cell 204.

[0046] Upon receiving the CHO command (and / or the CHO configuration list 212 and the NES CHO configuration 216) from the source cell 204, the UE stores the CHO RRC configuration of the target cell and begins conventional CHO condition evaluation (i.e., performing CHO measurements 222 to evaluate A3 or A5 conditions without applying a threshold offset) until a NES mode change of the source cell is detected. If configured, the UE 202 may use different CHO evaluation thresholds for different target cells.

[0047] If one or more candidate target cells meet the conventional CHO conditions, the UE 202 starts (eg, using a conventional CHO procedure, such as Figure 1A and Figure 1B 202 performs HO with one or more enhancements based on at least one target cell in NES mode. For example, if two or more candidate target cells meet the CHO condition, the UE may select the candidate target cell based on prioritizing normal cells that are not in NES mode (e.g., the first target cell 206) over cells in NES mode (e.g., the second target cell 208). If more than one normal cell meets the CHO condition, it may depend on the UE specific implementation to determine which normal cell to select for HO. Note that the UE 202 may determine the NES cell based on the configured cell list in CHO-Config. Therefore, it may not be necessary to detect which of the candidate target cells are in NES mode.

[0048] In another embodiment, if priority values ​​are configured for candidate target cells that meet the CHO condition, the UE 202 may select the candidate target cell with the highest configured priority value to perform HO. If more than one candidate target cell that meets the CHO condition has the same priority value, the UE may determine which candidate target cell to select for HO.

[0049] Otherwise, if no candidate target cell satisfies the legacy CHO condition, but the UE 202 detects that the source cell 204 enters NES mode, the UE 202 may switch to CHO-specific conditions (i.e., perform NES CHO measurements 224 and apply a threshold offset to the corresponding candidate target cell, or apply another CHO condition).

[0050] In one embodiment, the UE 202 detects that the source cell 204 has entered the NES mode based on the source cell 204 starting to block legacy UEs by monitoring the master information block (MIB) and / or system information block (SIB) of the source cell 204. For example, if the cellBarred bit in the MIB is set to true and a new bit (e.g., allowNESUE) in the first SIB (SIB1) is set to true, or the cell reservation bit (i.e., cellReservationForOtherUse or cellReservationForFutureUse) in SIB1 is set to true and a new bit (e.g., allowNESUE) in SIB1 is set to true, the UE determines that the source cell 204 has switched to the NES mode.

[0051] In addition, or in other embodiments, the source cell 204 may detect that the source cell 204 enters the NES mode when one or more of the following is received: RRC signaling or L1 / L2 signaling applying cell DTX / DRX is received from the source cell 204, RRC signaling or L1 / L2 signaling applying spatial element adaptation is received from the source cell 204, RRC signaling or L1 / L2 signaling applying PDSCH transmission power adaptation is received from the source cell 204, and / or UE group common or UE-specific L1 / L2 signaling is received indicating that the source cell 204 has switched to the NES mode. In some embodiments, the UE 202 is configured to respond to the group common or UE-specific L1 / L2 signaling indicating that the source cell 204 has switched to the NES mode with L2 signaling for confirmation (e.g., using a medium access control (MAC) control element (CE)).

[0052] After the configuration of the applicable NES CHO conditions (ie, after the UE 202 releases the legacy CHO configuration 214 and applies the NES CHO configuration 216), the UE 202 may start NES CHO measurements 224 for NES CHO condition evaluation to accelerate the execution of HO. Figure 2 In the example shown, UE 202 selects the second target cell 208 (i.e., the quality of cell 2 meets the CHO condition or the NESCHO condition, and UE 202 performs a handover to cell 2). For example, UE 202 may perform a random access channel (RACH) procedure with the selected candidate target cell. Once UE 202 becomes associated with the new cell on source cell 204 (and UE 202 may send an accompanying RRC reconfiguration complete message (RRCReconfigurationComplete) to the selected target cell), the CHO handover is complete. During the handover completion phase, the selected target cell sends a handover success message to source cell 204.

[0053] In certain embodiments, if two or more candidate target cells meet the NES CHO condition, the UE may select a candidate target cell based on prioritizing normal cells that are not in NES mode (e.g., the first target cell 206) over cells that are in NES mode (e.g., the second target cell 208). If more than one normal cell meets the NES CHO condition, it may be up to the UE implementation to determine which normal cell to select for HO. In another embodiment, if priority values ​​are configured for the candidate target cells that meet the NES CHO condition, the UE 202 may select the candidate target cell with the highest configured priority value for HO. If more than one candidate target cell that meets the NES CHO condition has the same priority value, it may be up to the UE implementation to determine which candidate target cell to select for HO.

[0054] Failure Handling

[0055] In one embodiment, if HO execution fails (e.g., caused by RACH failure), the UE may perform cell selection, wherein if both normal cells and NES cells configured in CHO are suitable, the normal cells may be prioritized during cell selection to perform handover.

[0056] In another embodiment, if the HO execution fails (eg, caused by RACH failure), the UE may perform cell selection, wherein if there are cells configured as suitable, the UE selects a cell to perform handover according to the configured priority value.

[0057] Inter-node signaling

[0058] In some embodiments, inter-node signaling is used to exchange NES modes and preferred priority values ​​between base stations. For example, the inter-node signaling may indicate the application of cell DTX / DRX from the source cell, spatial element adaptation from the source cell, PDSCH transmission power adaptation from the source cell, and / or paging enhancement.

[0059] As another example, the candidate target cell may use inter-node signaling to forward its preferred priority value to the source cell.However, in some such embodiments, it may be up to the source cell to determine the priority value to be included in the CHO configuration and / or NES CHO configuration.

[0060] Example Implementation

[0061] Figure 3 A flow chart illustrating a method 300 for a UE to perform CHO in a wireless network including a cell in NES mode according to one embodiment is illustrated. The method 300 includes measuring 302 a reference signal from a candidate target cell in the wireless network and reporting corresponding measurement values ​​to a source cell in the wireless network. The method 300 also includes receiving 304 a CHO configuration and an NES CHO configuration at the UE from the source cell. The method 300 also includes a handover execution phase of the CHO procedure, which includes evaluating 306 a CHO condition based on the CHO configuration. The handover execution phase also includes, in response to detecting that the source cell is in NES mode, switching 308 from evaluating the CHO condition based on the CHO configuration to performing an NES CHO evaluation based on the NES CHO configuration. The handover execution phase also includes selecting 310 a target cell from the candidate target cells based on the NES CHO evaluation, and completing 312 the handover to the target cell.

[0062] In some embodiments of the method 300, selecting the target cell includes prioritizing a first subset of the candidate target cells that are in a non-NES mode over a second subset of the candidate target cells that are in a NES mode.

[0063] In some embodiments of method 300, the NES CHO configuration includes a first NES CHO threshold offset. Evaluating a CHO condition includes comparing a measurement of a reference signal from a candidate target cell to a threshold to detect a CHO event. Performing the NES CHO evaluation includes comparing a measurement of a reference signal from one or more candidate target cells to the first NES CHO threshold offset to detect a CHO event.

[0064] In certain such embodiments of method 300, the NES CHO configuration further includes a second NES CHO threshold offset, and performing the NES CHO evaluation further includes comparing reference signal measurements from a first subset of the candidate target cells in non-NES mode to the first NES CHO threshold offset; and comparing reference signal measurements from a second subset of the candidate target cells in NES mode to the second NES CHO threshold offset. In certain such embodiments, at least one of the CHO configuration and the NES CHO configuration further includes, for each candidate target cell, an indication of operating in NES mode. In other embodiments, at least one of the CHO configuration and the NES CHO configuration further includes, for each candidate target cell or for a group of candidate target cells, a priority value to be used when selecting a target cell from the candidate target cells. The priority value may be based on a corresponding NES technology used by each candidate target cell or the group of candidate target cells. In other embodiments, at least one of the first NES CHO threshold offset and the second NES CHO threshold offset includes an RSRP offset or an RSRQ offset configured for a CHO event.

[0065] In some embodiments of method 300, the NES CHO configuration includes an NES CHO condition. Evaluating the CHO condition includes analyzing reference signal measurements from candidate target cells to detect a CHO event. Performing the NES CHO evaluation includes analyzing reference signal measurements from one or more of the candidate target cells to detect an NES CHO event based on the NES CHO condition. In some such embodiments, the NES CHO condition is satisfied when the RSRP or RSRQ of the target cell reaches a threshold.

[0066] In some embodiments, method 300 further includes, in response to detecting that the source cell is in NES mode, switching from a first S-measure configuration to a second S-measure configuration that defines when the UE performs measurements on candidate target cells based on quality of the source cell.

[0067] In some embodiments of the method 300 , evaluating the CHO condition based on the CHO configuration includes using different CHO evaluation thresholds for two or more of the candidate target cells.

[0068] In some embodiments of the method 300, evaluating the CHO condition based on the CHO configuration includes: in response to determining that more than one of the candidate target cells satisfies the CHO condition, prioritizing a first subset of the candidate target cells that are in non-NES mode over a second subset of the candidate target cells that are in NES mode. Some such embodiments further include following an order defined in a configured cell list in the CHO configuration to prioritize the first subset of the candidate target cells that are in non-NES mode and not detecting the second subset of the candidate target cells that are in NES mode.

[0069] In some embodiments of method 300, evaluating the CHO condition based on the CHO configuration includes: in response to determining that more than one candidate target cell among the candidate target cells meets the CHO condition, selecting one candidate target cell among the candidate target cells that meets the CHO condition and has a highest configured priority value to perform switching.

[0070] In some embodiments of method 300, detecting that the source cell is in NES mode includes one or more of the following: detecting that the source cell starts blocking legacy UEs by monitoring at least one of the MIB and SIB of the source cell; receiving RRC or L1 / L2 signaling applying cell DTX / DRX from the source cell; receiving RRC or L1 / L2 signaling applying spatial element adaptation from the source cell; receiving RRC or L1 / L2 signaling applying PDSCH transmission power adaptation from the source cell; and receiving UE group common L1 / L2 signaling or UE-specific L1 / L2 signaling triggering handover execution from the source cell. In some such embodiments, detecting that the source cell starts blocking legacy UEs by monitoring at least one of the MIB and SIB of the source cell includes: determining that the cellBarred bit in the MIB is set to true and the allowNESUE bit in SIB1 is set to true; or determining that the cellReserved bit in SIB1 is set to true and the allowNESUE bit in SIB1 is set to true. In certain embodiments, in response to receiving UE group common L1 / L2 signaling or UE specific L1 / L2 signaling triggering handover execution, method 300 further includes responding to the source cell with L2 signaling for confirmation.

[0071] In some embodiments, method 300 further includes, in response to determining that the handover execution has failed, performing a cell selection process, wherein if a first subset of candidate target cells configured in the CHO configuration that are in non-NES mode and a second subset of candidate target cells that are in NES mode are both suitable candidates, prioritizing the first subset over the second subset during the cell selection process.

[0072] In some embodiments, the method 300 further includes, in response to determining that the handover execution failed, performing a cell selection process, wherein if any candidate target cell configured in the CHO configuration is a suitable candidate, the configured priority value is followed during the cell selection process.

[0073]

[0066] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of method 300. The apparatus may be, for example, an apparatus that is a UE (such as wireless device 602 (UE), as described herein).

[0074] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 300. The non-transitory computer-readable medium may be, for example, a memory of a UE (such as memory 606 of wireless device 602 (UE), as described herein).

[0075] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuits operable to perform one or more elements of method 300. The apparatus may be, for example, an apparatus of a UE (such as wireless device 602 (UE), as described herein).

[0076] Embodiments contemplated herein include an apparatus comprising one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 300. The apparatus may be, for example, an apparatus of a UE (such as wireless device 602 (UE), as described herein).

[0077] Embodiments contemplated herein include a signal as described in or associated with one or more elements of method 300 .

[0078] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processor causes the processor to perform one or more elements of the method 300. The processor may be a processor of a UE (such as the processor 604 of the wireless device 602 (UE), as described herein). These instructions may be located, for example, in the processor and / or in a memory of the UE (such as the memory 606 of the wireless device 602 (UE), as described herein).

[0079] Figure 4 A flow chart illustrating a method 400 for a base station configured as a source cell to perform CHO in a wireless network including a cell in NES mode according to one embodiment is illustrated. The method 400 includes receiving 402 from a UE a measurement value corresponding to a reference signal received at the UE from a neighboring cell in the wireless network. The method 400 also includes determining 404 a candidate target cell among the neighboring cells based on the measurement value. The method 400 also includes sending 406 a CHO configuration from the base station to the UE to configure the candidate target cell at the UE, the CHO configuration including a CHO condition. The method 400 also includes sending 408 a NES CHO configuration from the base station to the UE to apply when the source cell is in NES mode. The method 400 also includes initiating 410 a CHO procedure between the UE and a target cell among the candidate target cells.

[0080] In some embodiments of the method 400, at least one of the CHO configuration and the NES CHO configuration further includes, for each of the candidate target cells, an indication to operate in NES mode.

[0081] In some embodiments of the method 400, at least one of the CHO configuration and the NES CHO configuration further includes, for each of the candidate target cells or for a group of candidate target cells, a priority value for selecting the target cell from the candidate target cells. In some such embodiments, the priority value is based on a corresponding NES technology used by each of the candidate target cells or the group of candidate target cells.

[0082] In some embodiments of method 400, the NES CHO configuration includes a first NES CHO threshold offset for NES CHO evaluation. In some such embodiments, the NES CHO configuration also includes a second NES CHO threshold offset, and the NES CHO evaluation is based on: a first comparison of reference signal measurements from a first subset of candidate target cells in non-NES mode with the first NES CHO threshold offset; and a second comparison of reference signal measurements from a second subset of candidate target cells in NES mode with the second NES CHO threshold offset. In some such embodiments, at least one of the first NES CHO threshold offset and the second NES CHO threshold offset includes an RSRP offset or an RSRQ offset configured for a CHO event.

[0083] In some embodiments of method 400, the NES CHO configuration includes an NES CHO condition, the CHO event is based on the CHO condition, and the NES CHO event is based on the NES CHO condition. In some such embodiments, the NES CHO condition is met when the RSRP or RSRQ of the target cell reaches a threshold.

[0084] In some implementations of method 400, at least one of the CHO configuration and the NES CHO configuration includes an indication of whether the source cell is in NES mode.

[0085] In some embodiments of method 400, in response to the source cell entering NES mode, the source cell performs one or more of the following operations: starting to bar legacy UEs via at least one of the MIB and SIB of the source cell; sending RRC or L1 / L2 signaling from the source cell to the UE for triggering cell DTX / DRX; sending RRC or L1 / L2 signaling from the source cell to the UE for triggering spatial element adaptation; sending RRC or L1 / L2 signaling from the source cell to the UE for triggering PDSCH transmission power adaptation; and sending UE group common L1 / L2 signaling or UE-specific L1 / L2 signaling from the source cell to the UE for triggering handover execution. In some such embodiments, starting to bar legacy UEs includes: sending the cellBarred bit set to true in the MIB and the allowNESUE bit set to true in SIB1; or sending the cellReserved bit set to true in SIB1 and the allowNESUE bit set to true in SIB1. In certain embodiments, in response to sending UE group common L1 / L2 signaling or UE specific L1 / L2 signaling triggering handover execution, the method 400 further includes receiving L2 signaling from the UE for confirmation.

[0086] Certain embodiments of method 400 further include receiving, at the source cell, inter-node signaling from the candidate target cells indicating whether the candidate target cells are respectively in NES mode. In certain such embodiments, the inter-node signaling indicates that the candidate target cells apply at least one of cell DTX and DRX. Additionally or in other embodiments, the inter-node signaling indicates that the candidate target cells apply spatial element adaptation, PDSCH transmission power adaptation, and / or paging enhancement.

[0087] In some embodiments, method 400 further includes receiving, at the source cell, inter-node signaling from the candidate target cells indicating one or more preferred priority values ​​respectively suggested by the candidate target cells. Certain such embodiments further include including, in the NES CHO configuration, a configured priority value based on the one or more preferred priority values ​​suggested by the candidate target cells.

[0088] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of method 400. The apparatus may be, for example, an apparatus that is a base station (such as network device 618 (base station), as described herein).

[0089] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 400. The non-transitory computer-readable medium may be, for example, a memory of a base station (such as memory 622 of network device 618 (base station), as described herein).

[0090] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuits operable to perform one or more elements of method 400. The apparatus may be, for example, an apparatus of a base station (such as network device 618 (base station), as described herein).

[0091] Embodiments contemplated herein include an apparatus comprising one or more processors and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 400. The apparatus may be, for example, a base station (such as network device 618 (base station), as described herein).

[0092] Embodiments contemplated herein include a signal as described in or associated with one or more elements of method 400 .

[0093] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processing element causes the processing element to perform one or more elements of method 400. The processor may be a processor of a base station (such as processor 620 of network device 618 (base station), as described herein). These instructions may be located, for example, in a processor and / or in a memory of a base station (such as memory 622 of network device 618 (base station), as described herein).

[0094] Figure 5 An example architecture of a wireless communication system 500 according to the embodiments disclosed herein is illustrated. The description provided below is for an example wireless communication system 500 operating in conjunction with the LTE system standard and / or the 5G or NR system standard provided in the 3GPP technical specifications.

[0095] like Figure 5 As shown, wireless communication system 500 includes UE 502 and UE 504 (although any number of UEs may be used). In this example, UE 502 and UE 504 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices capable of connecting to one or more cellular networks), but may include any mobile or non-mobile computing device configured for wireless communication.

[0096] UE 502 and UE 504 can be configured to be communicatively coupled to RAN 506. In an embodiment, RAN 506 can be NG-RAN, E-UTRAN, etc. UE 502 and UE 504 utilize connections (or channels) (shown as connection 508 and connection 510, respectively) with RAN 506, where each connection (or channel) includes a physical communication interface. RAN 506 may include one or more base stations (such as base station 512 and base station 514) that implement connection 508 and connection 510.

[0097] In this example, connection 508 and connection 510 are the air interfaces that enable such communicative coupling and may conform to the RAT employed by RAN 506, such as, for example, LTE and / or NR.

[0098] In some embodiments, UE 502 and UE 504 may also directly exchange communication data via side link interface 516. UE 504 is shown as being configured to access an access point (shown as AP 518) via connection 520. For example, connection 520 may include a local wireless connection, such as a connection compliant with any IEEE 802.11 protocol, wherein AP 518 may include In this example, AP 518 may not be connected to another network (eg, the Internet) through CN 524.

[0099] In an embodiment, UE 502 and UE 504 may be configured to communicate with each other or with base station 512 and / or base station 514 using orthogonal frequency division multiplexing (OFDM) communication signals over a multi-carrier communication channel in accordance with various communication techniques, such as, but not limited to, orthogonal frequency division multiple access (OFDMA) communication techniques (e.g., for downlink communication) or single-carrier frequency division multiple access (SC-FDMA) communication techniques (e.g., for uplink and ProSe or sidelink communication), although the scope of the embodiment is not limited in this respect. An OFDM signal may include multiple orthogonal subcarriers.

[0100] In some embodiments, all or part of base station 512 or base station 514 may be implemented as one or more software entities running on a server computer as part of a virtual network. Additionally, or in other embodiments, base station 512 or base station 514 may be configured to communicate with each other via interface 522. In embodiments where wireless communication system 500 is an LTE system (e.g., when CN 524 is an EPC), interface 522 may be an X2 interface. This X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) connected to an EPC and / or between two eNBs connected to an EPC. In embodiments where wireless communication system 500 is an NR system (e.g., when CN 524 is a 5GC), interface 522 may be an Xn interface. This Xn interface is defined between two or more base stations (e.g., two or more gNBs, etc.) connected to a 5GC, between base station 512 (e.g., a gNB) and an eNB connected to a 5GC, and / or between two eNBs connected to a 5GC (e.g., CN 524).

[0101] RAN 506 is shown as being communicatively coupled to CN 524. CN 524 may include one or more network elements 526 configured to provide various data and telecommunication services to customers / subscribers (e.g., UE 502 and users of UE 504) connected to CN 524 via RAN 506. The components of CN 524 may be implemented in one physical device or separate physical devices that include components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0102] In an embodiment, CN 524 may be an EPC, and RAN 506 may be connected to CN 524 via an S1 interface 528. In an embodiment, S1 interface 528 may be divided into two parts: an S1 user plane (S1-U) interface, which carries traffic data between base station 512 or base station 514 and a serving gateway (S-GW); and an S1-MME interface, which is a signaling interface between base station 512 or base station 514 and a mobility management entity (MME).

[0103] In an embodiment, CN 524 may be a 5GC, and RAN 506 may be connected to CN 524 via an NG interface 528. In an embodiment, NG interface 528 may be divided into two parts: an NG user plane (NG-U) interface, which carries traffic data between base station 512 or base station 514 and a user plane function (UPF); and an S1 control plane (NG-C) interface, which is a signaling interface between base station 512 or base station 514 and an access and mobility management function (AMF).

[0104] Generally speaking, the application server 530 may be an element that provides applications (e.g., packet-switched data services) that utilize Internet Protocol (IP) bearer resources with the CN 524. The application server 530 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE 502 and the UE 504 via the CN 524. The application server 530 may communicate with the CN 524 via an IP communication interface 532.

[0105] Figure 6 A system 600 is illustrated for performing signaling 634 between a wireless device 602 and a network device 618 according to embodiments disclosed herein. The system 600 can be part of a wireless communication system as described herein. The wireless device 602 can be, for example, a UE of the wireless communication system. The network device 618 can be, for example, a base station (e.g., an eNB or gNB) of the wireless communication system.

[0106] The wireless device 602 may include one or more processors 604. The processor 604 may execute instructions to perform various operations for the wireless device 602, as described herein. The processor 604 may include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof, configured to perform the operations described herein.

[0107] The wireless device 602 may include a memory 606. The memory 606 may be a non-transitory computer-readable storage medium that stores instructions 608 (which may include, for example, instructions executed by the processor 604). The instructions 608 may also be referred to as program code or a computer program. The memory 606 may also store data used by the processor 604 and results computed by the processor.

[0108] The wireless device 602 may include one or more transceivers 610, which may include radio frequency (RF) transmitter and / or receiver circuitry that uses an antenna 612 of the wireless device 602 to facilitate signaling (e.g., signaling 634) to and / or from the wireless device 602 and other devices (e.g., network device 618) according to a corresponding RAT.

[0109] The wireless device 602 may include one or more antennas 612 (e.g., one, two, four, or more). For embodiments with multiple antennas 612, the wireless device 602 may leverage the spatial diversity of such multiple antennas 612 to transmit and / or receive multiple different data streams on the same time-frequency resources. This behavior may be referred to as, for example, multiple-input, multiple-output (MIMO) behavior (referring to the multiple antennas used at each of the transmitting and receiving devices to implement this aspect). MIMO transmissions by the wireless device 602 may be implemented based on precoding (or digital beamforming) applied to the wireless device 602, which multiplexes the data streams across the antennas 612 based on known or assumed channel characteristics, such that each data stream is received at an appropriate signal strength relative to the other streams and at a desired location in the spatial domain (e.g., the location of the receiver associated with that data stream). Certain embodiments may utilize single-user MIMO (SU-MIMO) methods (where all data streams are directed to a single receiver) and / or multi-user MIMO (MU-MIMO) methods (where individual data streams may be directed to separate (different) receivers at different locations in the spatial domain).

[0110] In certain embodiments with multiple antennas, the wireless device 602 may implement analog beamforming techniques whereby the phases of the signals transmitted by the antennas 612 are adjusted relative to each other so that the (joint) transmissions of the antennas 612 can be directed (this is sometimes referred to as beam steering).

[0111] The wireless device 602 may include one or more interfaces 614. The interfaces 614 may be used to provide input to or output from the wireless device 602. For example, the wireless device 602 (as a UE) may include an interface 614, such as a microphone, a speaker, a touch screen, and buttons, to allow a user of the UE to input and / or output to the UE. Other interfaces of such a UE may be composed of transmitters, receivers, and other circuits (e.g., in addition to the transceiver 610 / antenna 612 described above) that allow communication between the UE and other devices, and may be based on known protocols (e.g., and etc.) to perform the operation.

[0112] The wireless device 602 may include a CHO switching module 616. The CHO switching module 616 may be implemented via hardware, software, or a combination thereof. For example, the CHO switching module 616 may be implemented as a processor, circuitry, and / or instructions 608 stored in the memory 606 and executed by the processor 604. In some examples, the CHO switching module 616 may be integrated within the processor 604 and / or the transceiver 610. For example, the CHO switching module 616 may be implemented by a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 604 or the transceiver 610.

[0113] The CHO switching module 616 may be used in various aspects of the present disclosure, such as Figure 1A 、 Figure 1B 、 Figure 2 and Figure 3 all aspects.

[0114] The network device 618 may include one or more processors 620. The processors 620 may execute instructions to perform various operations for the network device 618, as described herein. The processors 620 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0115] The network device 618 may include a memory 622. The memory 622 may be a non-transitory computer-readable storage medium that stores instructions 624 (which may include, for example, instructions to be executed by the processor 620). The instructions 624 may also be referred to as program code or a computer program. The memory 622 may also store data used by the processor 620 and results calculated by the processor.

[0116] The network device 618 may include one or more transceivers 626, which may include RF transmitter and / or receiver circuitry that uses an antenna 628 of the network device 618 to facilitate signaling (e.g., signaling 634) to and / or from the network device 618 and other devices (e.g., wireless device 602) according to a corresponding RAT.

[0117] The network device 618 may include one or more antennas 628 (e.g., one, two, four, or more). In embodiments with multiple antennas 628, the network device 618 may perform MIMO, digital beamforming, analog beamforming, beamsteering, etc. as described.

[0118] The network device 618 may include one or more interfaces 630. The interfaces 630 may be used to provide input to or output from the network device 618. For example, the network device 618 (base station) may include an interface 630 consisting of a transmitter, a receiver, and other circuits (e.g., in addition to the transceiver 626 / antenna 628 already described) that enables the base station to communicate with other equipment in the core network and / or enables the base station to communicate with external networks, computers, databases, etc., for the purpose of operating, managing, and maintaining the base station or other equipment operatively connected to the base station.

[0119] The network device 618 may include a CHO switch module 632. The CHO switch module 632 may be implemented via hardware, software, or a combination thereof. For example, the CHO switch module 632 may be implemented as a processor, circuitry, and / or instructions 624 stored in the memory 622 and executed by the processor 620. In some examples, the CHO switch module 632 may be integrated within the processor 620 and / or the transceiver 626. For example, the CHO switch module 632 may be implemented by a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 620 or the transceiver 626.

[0120] The CHO switching module 632 may be used in various aspects of the present disclosure, such as Figure 1A 、 Figure 1B 、 Figure 2 and Figure 4 all aspects.

[0121] For one or more embodiments, at least one of the components described in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described herein in conjunction with one or more of the preceding figures may be configured to operate according to one or more of the examples described herein. For another example, circuitry associated with a UE, base station, network element, or the like as described above in conjunction with one or more of the preceding figures may be configured to operate according to one or more of the examples described herein.

[0122] Unless otherwise expressly stated, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise forms disclosed. In view of the above teachings, modifications and variations are possible or can be obtained from the practice of the various embodiments.

[0123] Embodiments and implementations of the systems and methods described herein may include various operations that may be embodied in machine-executable instructions to be executed by a computer system. A computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). A computer system may include hardware components that include specific logic for performing the operations; or may include a combination of hardware, software, and / or firmware.

[0124] It should be appreciated that the systems described herein include descriptions of specific embodiments. These embodiments can be combined into a single system, partially combined into other systems, separated into multiple systems, or otherwise divided or combined. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment may be used in conjunction with another embodiment. For clarity, these parameters, attributes, aspects, etc. are described only in relation to one or more embodiments, and it should be appreciated that these parameters, attributes, aspects, etc. may be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless expressly stated otherwise herein.

[0125] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly stated to users.

[0126] Although the foregoing has been described in considerable detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles of the invention. It should be noted that there are many alternative ways of implementing both the processes and the apparatus described herein. The embodiments of the present invention are therefore to be considered illustrative and not restrictive, and the description is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Claims

1. A method for performing conditional handover (CHO) by a user equipment (UE) in a wireless network including a cell in a network energy saving (NES) mode, the method comprising: measuring a reference signal from a candidate target cell in the wireless network, and reporting a corresponding measurement value to a source cell in the wireless network; receiving, at the UE, a CHO configuration and an NES CHO configuration from the source cell; During the handover execution phase of the CHO process: evaluating a CHO condition based on the CHO configuration; in response to detecting that the source cell is in the NES mode, switching from evaluating the CHO condition based on the CHO configuration to performing NES CHO evaluation based on the NES CHO configuration; selecting a target cell from the candidate target cells based on the NES CHO evaluation; as well as The handover to the target cell is completed.

2. The method according to claim 1, wherein selecting the target cell comprises: A first subset of the candidate target cells that are in non-NES mode is prioritized over a second subset of the candidate target cells that are in the NES mode.

3. The method of claim 1 or claim 2, wherein the NES CHO configuration comprises a first NES CHO threshold offset; Wherein evaluating the CHO condition comprises: comparing a measurement result of the reference signal from the candidate target cell with a threshold to detect a CHO event; and The performing of the NES CHO evaluation includes comparing the measurement results of the reference signals from one or more of the candidate target cells with the first NES CHO threshold offset to detect the CHO event.

4. The method of claim 3, wherein the NES CHO configuration further comprises a second NES CHO threshold offset, and wherein performing the NES CHO evaluation further comprises: comparing the measurement results of the reference signals from a first subset of the candidate target cells in non-NES mode with the first NES CHO threshold offset; as well as The measurements of the reference signals from a second subset of the candidate target cells in NES mode are compared to the second NES CHO threshold offset.

5. The method of claim 4, wherein at least one of the CHO configuration and the NES CHO configuration further comprises: For each of the candidate target cells, an indication to operate in the NES mode.

6. The method of claim 4, wherein at least one of the CHO configuration and the NES CHO configuration further comprises: For each of the candidate target cells or for a group of the candidate target cells, a priority value to be used when selecting the target cell from the candidate target cells.

7. The method of claim 6, wherein the priority value is based on a respective NES technology used by each of the candidate target cells or the group of candidate target cells.

8. The method of claim 4, wherein at least one of the first NES CHO threshold offset and the second NES CHO threshold offset comprises a reference signal received power (RSRP) offset or a reference signal received quality (RSRQ) offset configured for the CHO event.

9. The method of claim 1 or claim 2, wherein the NES CHO configuration comprises NES CHO conditions; Wherein evaluating the CHO condition comprises: analyzing measurement results of the reference signal from the candidate target cell to detect a CHO event; and The performing of the NES CHO evaluation includes analyzing the measurement results of the reference signals from one or more candidate target cells among the candidate target cells to detect an NES CHO event based on the NES CHO condition.

10. The method according to claim 9, wherein the NES CHO condition is met when a reference signal received power (RSRP) or a reference signal received quality (RSRQ) of the target cell reaches a threshold.

11. The method according to claim 1 , further comprising: In response to detecting that the source cell is in the NES mode, switching from a first S-measure configuration to a second S-measure configuration that defines when the UE performs measurements on the candidate target cell based on the quality of the source cell.

12. The method of claim 1 , wherein evaluating the CHO condition based on the CHO configuration comprises: Different CHO evaluation thresholds are used for two or more candidate target cells among the candidate target cells.

13. The method of claim 1 , wherein evaluating the CHO condition based on the CHO configuration comprises: In response to determining that more than one of the candidate target cells satisfies the CHO condition, a first subset of the candidate target cells that are in non-NES mode is prioritized over a second subset of the candidate target cells that are in the NES mode.

14. The method according to claim 13, further comprising: An order defined in a configured cell list in the CHO configuration is followed to prioritize the first subset of the candidate target cells in the non-NES mode, without detecting the second subset of the candidate target cells in the NES mode.

15. The method of claim 1 , wherein evaluating the CHO condition based on the CHO configuration comprises: In response to determining that more than one of the candidate target cells satisfy the CHO condition, one of the candidate target cells satisfying the CHO condition and having a highest configured priority value is selected to perform the handover.

16. The method of claim 1 , wherein detecting that the source cell is in the NES mode comprises one or more of: detecting, by monitoring at least one of a master information block (MIB) and a system information block (SIB) of the source cell, that the source cell starts to block legacy UEs; receiving radio resource control (RRC) or layer 1 / layer 2 (L1 / L2) signaling for applying cell discontinuous transmission and discontinuous reception (DTX / DRX) from the source cell; receiving the RRC or L1 / L2 signaling to which spatial element adaptation is applied from the source cell; receiving the RRC or L1 / L2 signaling for applying physical downlink shared channel (PDSCH) transmission power adaptation from the source cell; and Receive UE group common L1 / L2 signaling or UE dedicated L1 / L2 signaling triggering handover execution from the source cell.

17. The method of claim 16, wherein detecting that the source cell starts to block the legacy UE by monitoring at least one of the MIB and the SIB of the source cell comprises: Determining that the cellBarred bit in the MIB is set to true and the allowNESUE bit in a first SIB (SIB1) is set to true; or It is determined that the cell reservation bit in the SIB1 is set to true and the allowNESUE bit in the SIB1 is set to true.

18. The method according to claim 16, wherein in response to receiving the UE group common L1 / L2 signaling or the UE dedicated L1 / L2 signaling that triggers the handover execution, the method further comprises: L2 signaling is used to respond to the source cell for confirmation.

19. The method according to claim 1, further comprising: In response to determining that the handover execution has failed, a cell selection process is performed, wherein if a first subset of the candidate target cells configured in the CHO configuration that are in non-NES mode and a second subset of the candidate target cells that are in the NES mode are both suitable candidates, the first subset is prioritized over the second subset during the cell selection process.

20. The method according to claim 1, further comprising: In response to determining that the handover execution has failed, a cell selection procedure is performed, wherein if any of the candidate target cells configured in the CHO configuration is a suitable candidate, a configured priority value is followed during the cell selection procedure.

21. An apparatus comprising means for performing the method according to any one of claims 1 to 20.

22. A computer-readable medium comprising instructions, which, when executed by one or more processors of an electronic device, cause the electronic device to perform the method according to any one of claims 1 to 20.

23. An apparatus comprising logic components, modules or circuits for performing the method of any one of claims 1 to 20.

Images