NR handover, RLM, BFD and CBD with CCA

Abstract

The present disclosure relates to NR handover, RLM, BFD, and CBD with CCA. Some aspects relate to apparatuses and methods implementing mechanisms for performing handover, radio link monitoring (RLM), beam failure detection (BFD), and candidate beam detection (CBD) within unlicensed spectrum upon occurrence of a listen-before-talk (LBT) failure and / or upon a user equipment (UE) performing a receive (RX) beam sweep. For example, a UE is configured to receive a handover command for connecting to a target cell. The UE is further configured to determine a search time and an interruption time uncertainty during a handover procedure initiated by the handover command and in response to an LBT failure or the UE performing a beam sweep operation. The UE can further determine a handover delay based on the search time and the interruption time uncertainty. The UE can stop the handover procedure in response to a time period for performing the handover procedure exceeding the handover delay.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 295,143, filed on December 30, 2021, which is incorporated herein by reference in its entirety. Background Technology Technical Field

[0003] The aspects described generally relate to wireless communications in unlicensed spectrum.

[0004] Related fields

[0005] Unlicensed spectrum plays a crucial role in current wireless communication technologies. For example, the fifth-generation (5G) New Radio (NR) in unlicensed spectrum (NR-U) provides cellular operators with the technology to integrate unlicensed spectrum into 5G networks. NR-U allows both uplink and downlink operation in unlicensed bands, thereby supporting new features such as wideband carriers.

[0006] The current NR operation has been extended to the 71 GHz spectrum to cover the spectrum from 52.6 GHz to 71 GHz. Within this spectrum band, channel access in both the downlink and uplink can rely on the Listen-Before-Tell (LBT) characteristic. Before making any transmission, the wireless device or base station can first "sensor" the communication channel in the unlicensed spectrum as "idle". Additionally, this spectrum band can be designated as part of Frequency Range 2 (FR2). Summary of the Invention

[0007] Some aspects of this disclosure relate to apparatus and methods for performing handover, radio link monitoring (RLM), beam fault detection (BFD), and candidate beam detection (CBD) in unlicensed spectrum when an LBT failure occurs and / or when a user equipment (UE) is performing a receive (RX) beam scan. For example, some aspects of this disclosure provide a handover interruption time, as part of a handover delay, to be used by the UE to perform handover in unlicensed spectrum when an LBT failure occurs and / or when the UE is about to perform an RX beam scan. Additionally, some aspects of this disclosure provide an evaluation time for the UE to perform RLM, BFD, and / or CBD when an LBT failure occurs and / or when the UE is about to perform an RX beam scan.

[0008] Some aspects of this disclosure relate to a user equipment (UE). The UE includes a transceiver configured to wirelessly communicate with a serving cell, and a processor communicatively coupled to the transceiver. The processor is configured to use the transceiver to receive a handover command for connecting to a target cell, and in response to the handover command, initiate a handover procedure. The processor is further configured to determine a search time and an interruption time uncertainty during the handover procedure initiated by the handover command and in response to a Listen-After-Talk (LBT) failure or the UE performing a beam scanning operation. The processor may further determine a handover delay based on the search time and the interruption time uncertainty. In response to the time period for executing the handover procedure exceeding the handover delay, the processor may stop the handover procedure.

[0009] In some respects, the processor is further configured to, in response to the time period for performing the handover procedure exceeding the handover delay, rebuild the connection with the serving cell or establish a connection with the target cell or a third cell.

[0010] In some respects, the processor is further configured to determine the search time based at least on: (1) the number of unavailable Measurement Timing Configuration (SMTC) opportunities based on Synchronization Signal Block (SSB), or (2) the number of SMTC opportunities on which the UE does not detect any SSB during an in-frequency detection cycle or an inter-frequency detection cycle.

[0011] In some respects, the processor is further configured to determine the interruption time uncertainty based on (1) the number of consecutive synchronization signal blocks (SSBs) to PRACH timing associated periods during which no physical random access channel (PRACH) timing is available for PRACH transmission or (2) the number of consecutive PRACH timing periods during which the UE cannot perform PRACH transmission.

[0012] In some aspects, the processor is further configured to compare the time interval between the two closest successful SSB measurements in the time domain with a time threshold, and in response to the time interval exceeding the time threshold, reset the search time and redetermine the search time. According to some aspects, when the base station (BS) transmits an SSB and the BS SSB TX beam and the UE RX beam are aligned, the UE will have a successful SSB measurement and / or detection.

[0013] In some aspects, the processor is further configured to determine an evaluation period for radio link monitoring (RLM) based on the LBT failure or the UE performing beam scanning operations, and to perform RLM operations using the evaluation period. The processor can also be configured to compare the time period between the two closest successful SSBs or CSI-RS (Channel State Information Reference Signals) in the time domain with a threshold, and, in response to the time period exceeding the threshold, reset and redetermine the evaluation period.

[0014] In some aspects, the processor is further configured to determine an evaluation period for radio link monitoring (BFD) based on an LBT failure or beam scanning operation performed by the UE, and to perform BFD operations using this evaluation period. The processor may be further configured to compare the time interval between the two closest successful SSB or CSI-RS measurements and / or detections in the time domain with a threshold, and, in response to the time interval exceeding the threshold, reset and redetermine the evaluation period.

[0015] In some aspects, the processor is further configured to determine an evaluation period for candidate beam detection (CBD) based on the LBT failure or the UE performing beam scanning operations, and to perform CBD operations using this evaluation period. The processor may be further configured to compare the time interval between the two closest successful SSB or CSI-RS measurements and / or detections in the time domain with a threshold, and, in response to the time interval exceeding the threshold, reset and redetermine the evaluation period.

[0016] In some respects, the transceiver is configured to operate on unlicensed spectrum in the 52.6 GHz to 71 GHz range as part of Frequency Range 2 (FR2).

[0017] Some aspects of this disclosure relate to a method comprising: receiving a handover command for connecting to a target cell by a user equipment (UE), and initiating a handover procedure in response to the handover command. The method further comprises: determining a search time and an interruption time uncertainty during the initiated handover procedure in response to a Listen-After-Talk (LBT) failure or the UE performing a beam scanning operation. The method further comprises: determining a handover delay based on the search time and the interruption time uncertainty. In response to the time period for performing the handover procedure exceeding the handover delay, the method comprises: stopping the handover procedure.

[0018] Some aspects of this disclosure relate to a non-transitory computer-readable medium storing instructions. When executed by a processor of a user equipment (UE), these instructions cause the processor to perform operations including receiving a handover command for connecting to a target cell and initiating a handover procedure in response to the handover command. These operations also include determining a search time and an interruption time uncertainty during the handover procedure in response to a Listen-After-Speak (LBT) failure or when the UE performs a beam scan operation. These operations also include determining a handover delay based on the search time and the interruption time uncertainty. In response to the time period for executing the handover procedure exceeding the handover delay, the method includes either stopping the handover procedure or continuing the handover procedure until a corresponding handover timer (e.g., T304) expires.

[0019] The content of this invention is provided for illustrative purposes only, to provide an understanding of the subject matter described herein. Therefore, the features described above are merely illustrative and should not be construed as narrowing the scope or substance of the subject matter of this disclosure. Other features, aspects, and advantages of this disclosure will become apparent from the following detailed description, the accompanying drawings, and the claims. Attached Figure Description

[0020] The accompanying drawings, which are incorporated herein and form part of this specification, illustrate the present disclosure and, together with the specification, further serve to explain the principles of the disclosure and enable those skilled in the art to make and use the disclosure.

[0021] Figure 1 An exemplary system is shown that implements some aspects of this disclosure to perform handover, RLM, BFD, and CBD in unlicensed spectrum in the event of an LBT failure and / or when the UE is performing an RX beam scan.

[0022] Figure 2 A block diagram of an exemplary system of an electronic device is shown, which implements some aspects of this disclosure for performing handover, RLM, BFD, and CBD in unlicensed spectrum in the event of an LBT failure and / or when the UE performs an RX beam scan.

[0023] Figure 3 An exemplary method is shown for a system (e.g., a UE) that supports mechanisms for performing handover, RLM, BFD, and CBD in unlicensed spectrum in the event of an LBT failure and / or when the UE performs an RX beam scan, according to some aspects of this disclosure.

[0024] Figure 4 Another exemplary method is shown for a system (e.g., a UE) that supports mechanisms for performing RLM, BFD, and CBD in unpermitted spectrum in the event of an LBT failure and / or when the UE performs an RX beam scan, according to some aspects of this disclosure.

[0025] Figure 5 It is an exemplary computer system for implementing some aspects or parts thereof.

[0026] This disclosure is described with reference to the accompanying drawings. In the drawings, the same reference numerals generally indicate the same or similarly functional elements. Furthermore, the leftmost numeral of the reference numerals generally appears first in the drawings. Detailed Implementation

[0027] In unlicensed spectrum, the LBT mechanism can be performed by the UE using a sensing beam to check for channel occupancy via Clear Channel Assessment (CCA) before utilizing the channel. The UE's sensing beam can refer to the antenna beam (referred to as the "beam") used by the UE to sense channel occupancy. CCA uses energy detection (ED) to detect the presence (e.g., channel busy) or absence (e.g., channel idle) of other signals on the channel. If the energy detected during the initial CCA period is below a certain threshold, the channel is considered idle, and the device can utilize the channel for a period known as the Channel Occupancy Time (COT). Conversely, if the energy detected during the initial CCA period is above the threshold, the channel is considered busy, and the device cannot utilize the channel. In addition to the UE, or as an alternative to the UE, base stations (e.g., evolved Node B (eNB), next-generation Node B (gNB), etc.) can also perform the LBT mechanism using CCA before utilizing the channel.

[0028] The base station can use transmit (TX) beam scanning to send data, control information, etc., to the UE. The base station can use different beams in different directions to transmit, for example, synchronization signal blocks (SSBs) to the UE. Similarly, the UE can use RX beam scanning to determine and detect beams (and / or one or more SSBs) from the base station.

[0029] If the LBT mechanism performed by the UE fails (e.g., the UE determines that the sensed channel is busy), the UE cannot transmit in the uplink. Alternatively, if the LBT mechanism performed by the base station fails (e.g., the base station determines that the sensed channel is busy), the base station cannot transmit the SSB to the UE, and therefore the UE cannot detect the SSB. Additionally, if the UE's RX beam is not aligned with the base station's TX beam (e.g., the TX beam transmitting the SSB), the UE cannot successfully detect the SSB.

[0030] Some aspects of this disclosure relate to apparatus and methods for implementing mechanisms for performing handover, radio link monitoring (RLM), beam fault detection (BFD), and candidate beam detection (CBD) in unlicensed spectrum when an LBT failure occurs (due to, for example, beam misalignment) and / or when the UE performs an RX beam scan.

[0031] Figure 1 An exemplary system 100 is shown, illustrating mechanisms for performing handover, RLM, BFD, and CBD in unlicensed spectrum in the event of an LBT failure and / or while the UE is performing an RX beam scan, according to some aspects of this disclosure. The exemplary system 100 is provided for illustrative purposes only and is not intended to limit the aspects disclosed.

[0032] System 100 may include, but is not limited to, network nodes (e.g., base stations, such as eNB, gNB) 101 and 103 and electronic devices (e.g., UE) 105. Electronic device 105 (hereinafter referred to as UE 105) may include electronic devices configured to operate based on a variety of wireless communication technologies. These technologies may include, but are not limited to, technologies based on 3GPP standards. For example, UE 105 may include electronic devices configured to operate using Rel-17 or another 3GPP standard. UE 105 may include, but is not limited to: wireless communication devices, smartphones, laptops, desktop computers, tablets, personal assistants, monitors, televisions, wearable devices, Internet of Things (IoT) devices, vehicle communication devices, etc. Network nodes 101 and 103 (hereinafter referred to as base stations or cells) may include nodes configured to operate based on a variety of wireless communication technologies (such as, but not limited to, technologies based on 3GPP standards). For example, base stations 101 and 103 may include nodes configured to operate using Rel-17 or another 3GPP standard.

[0033] According to some aspects, UE 105 and base stations 101 and 103 are configured to implement mechanisms for triggering UE 105 to perform a handover procedure. For example, UE 105 may connect to and communicate with base station 101 (e.g., serving cell). If one or more conditions are met, UE 105 may perform a handover operation to connect to and communicate with base station 103 (e.g., target cell). In some examples, the handover procedure may include a UE-initiated handover or a network-initiated handover. Additionally or alternatively, the handover procedure may include intra-frequency handover (e.g., when UE 105 moves to the target cell, it remains on the same channel) or inter-frequency handover (e.g., when UE 105 moves to the target cell, it uses a different channel). The aspects of this disclosure can be used with any type of handover procedure.

[0034] In one example of inter-frequency and / or intra-frequency handover, base station 101 may initiate a handover. For example, base station 101 may send a handover request to base station 103. Base station 103 may perform admission control and transmit a handover confirmation to base station 101. The handover confirmation may include Radio Resource Control (RRC) configuration. In response to the handover confirmation, base station 101 may send a handover command to UE 105. The handover command may include RRC configuration. Alternatively or additionally, the handover command may include information associated with base station 103 (e.g., cell identifier (ID), etc.) that UE 105 can use to access and connect to base station 103. UE 105 may use the handover command from base station 101 to hand over to base station 103. After the handover, UE 105 may send a handover completion message to the target base station 103.

[0035] In one example of a network-initiated handover, UE 105 may receive handover information from base station 101. For example, UE 105 may receive measurement configurations for handover from base station 101. In response, UE 105 may perform quality measurements on beam reference signals, for example, but not limited to, from neighboring cells. After performing the measurements, UE 105 may send a measurement report to base station 101. The measurement report may include quality measurement results from different neighboring cells. Based on the measurement report, base station 101 may determine a target cell (e.g., base station 103). In some examples, base station 101 may communicate with base station 103 as discussed above to send a handover request and receive a handover confirmation. Alternatively or concurrently, base station 101 may send a handover command to UE 105. The handover command may include RRC connection reconfiguration and information associated with base station 103. UE 105 may use the handover command from base station 101 to handover to base station 103. After the handover, UE 105 may send a handover completion message to the target base station 103, which may include information about RRC connection reconfiguration completion.

[0036] In one example of a UE-initiated handover, UE 105 may receive handover information from base station 101. For example, UE 105 may receive a measurement configuration for handover from base station 101. In response, UE 105 may perform quality measurements on beam reference signals, such as, but not limited to, those from neighboring cells. After performing the measurements, UE 105 may send a measurement report to base station 101. The measurement report may include quality measurement results from different neighboring cells. Based on the measurement report, base station 101 may determine a list of possible target cells (including, for example, base station 103). Base station 101 may send the list of possible target cells and the information associated with the list of possible target cells to UE 105, for example, in an RRC connection reconfiguration. Alternatively or additionally, base station 101 may provide a measurement configuration for UE 105 to complete its handover. UE 105 may select a target cell (e.g., base station 105) from the list of possible target cells. For example, UE 105 may select a target cell (e.g., base station 105) based on information associated with the target cell provided by base station 101 (e.g., quality measurement results). After selecting a target cell, UE 105 can switch to and connect to the target cell. In some examples, UE 105 can use an RRC connection re-establishment procedure to connect to the target cell. The RRC connection re-establishment procedure may include random access in the selected cell, an RRC connection re-establishment request, an RRC connection re-establishment response, and an RRC connection re-establishment completion message.

[0037] The handover procedure discussed above is provided as an example and is not intended to limit any aspect of this disclosure. The mechanisms of this disclosure for performing handover in unlicensed spectrum in the event of an LBT failure and / or while the UE is performing an RX beam scan can be applied to any handover procedure.

[0038] According to some aspects, UE 105 performs a handover procedure within a handover delay. In some examples, when UE 105 (e.g., from base station 101) receives an RRC message indicating a handover, UE 105 will be prepared to begin transmitting a new uplink physical random access channel (PRACH) within the number of handover delay seconds from the end of the last transmit time interval (TTI) containing the RRC command. In some examples, the handover delay may include two components: (1) the maximum RRC procedure delay plus (2) and the interruption time. In some examples, the maximum RRC procedure delay is defined in technical specification (TS) 38.331, which is incorporated herein by reference in its entirety. As discussed in more detail below, some aspects of this disclosure relate to the interruption time in the event of an LBT failure and / or when UE 105 performs an RX beam scan during an FR2-to-FR2 handover.

[0039] For example, if UE 105 is about to perform a handover procedure (or is performing a handover procedure), UE 105 can determine that an LBT failure has occurred at the base station or that the RX beam is misaligned with the base station's TX beam (beam misalignment) if it cannot successfully detect an SSB transmitted by the base station. UE 105 can use the interruption time as disclosed herein to determine the handover delay.

[0040] Depending on several factors, UE 105 will need to perform a handover procedure within the handover delay. If the handover procedure takes longer than the handover delay, the connection between UE 105 and base station 101 may be dropped because the link quality was poor before UE 105 connected to base station 103. Therefore, if the handover procedure takes longer than the handover delay, UE 105 will need to rebuild its connection with a base station, which could be base station 101 or 103. Figure 1 Another base station not shown. For example, UE 105 performs an RRC connection reconstruction procedure to connect with base station 101. Alternatively, UE 105 will find a new cell and establish a connection with it. For example, UE 105 performs an RRC connection setup procedure to connect with the new cell.

[0041] According to some aspects, the interrupt time for FR2 to FR2 switching can be defined as follows:

[0042] T interruption =T search +T IU +T processing +T Δ +T margin Formula (1).

[0043] Here, T search This refers to the time allotted for searching for a target cell when UE 105 receives a handover command. Additionally, T... IU This refers to the uncertainty in the interruption time during the acquisition of the first available PRACH in a new cell. processing This is the time allotted for UE 105 processing. According to some examples, T... processing Up to 20ms. T Δ It is the time used for fine-grained time tracking and acquiring complete timing information for the target cell. T margin This is the time allotted for UE 105 to perform SSB post-processing. In some examples, T margin It can be as long as 2ms.

[0044] Based on some examples, without considering LBT failures and RX beam scanning used to determine the outage time, if the target cell (e.g., base station 105) is known, then T search It can be 0ms(T) search=0ms). If the target cell is an unknown frequency cell and the target cell has a signal-to-noise ratio (SNR) such as Equal to or greater than -2dB (e.g., ), then T search =8*T rs ms. If the target cell is an unknown inter-frequency cell and the target cell has an SNR such as Equal to or greater than -2dB (e.g., ), then T search =8*3*T rs ms. In this example, the RX beam scan factor (also known as the RX beam scan factor) is 8. Additionally, in this example, if the SSB-based measurement timing configuration (SMTC) for the target cell has been provided to UE 105 in the handover command, then T rs The SMTC configuration of the target cell is periodic. Otherwise, T rs This is an SMTC configured with a measObjectNR having the same SSB frequency and subcarrier spacing. Additionally, in this example, LBT failures and RX beam scanning are not considered, and T... IU It can reach the sum of the timing correlation period from SSB to PRACH plus 10ms.

[0045] Some aspects of this disclosure relate to determining the T when an LBT failure and / or beam misalignment occurs. search and T IU As discussed above, when the LBT fails, base station 101 cannot transmit an SSB and / or UE 105 cannot detect an SSB. Additionally, when the UE 105 RX beam is not aligned with the SSB transmission beam, UE 105 cannot successfully detect an SSB. Considering these conditions, T search and T IU It can be defined as the interrupt time (T) that causes the switching delay. interuption The component can compensate for delays caused by LBT failures and / or RX beam scanning.

[0046] Depending on several factors, considering LBT failure and RX beam scanning used to determine the interruption time, the following options can be used to determine T. search .

[0047] Option 1 – In this example, for cells within an unknown frequency range:

[0048] T search =N*(1+SR1_intra)*Trs ms formula (2).

[0049] For unknown inter-frequency cells:

[0050] Tsearch =N*(3+SR1_inter)*Trs ms formula (3).

[0051] Here, N can be the RX beam scanning factor. In some examples, N can be 8 (e.g., for FR2-1). In some examples, N can be greater than 8 (e.g., for FR-2-2). However, aspects of this disclosure are not limited to these examples and may include other values ​​of N.

[0052] SR1_intra and SR1_inter are the number of rounds of RX beam scanning (e.g., SR = 0, 1, 2, ...). In this example, N*SR1_intra or N*SR1_inter is the number of SMTC opportunities that are unavailable due to beam misalignment or on which no SSB was successfully detected at UE 105 during the in-frequency and inter-frequency detection cycles. Depending on some aspects, within the initial N*1 or N*3 SMTCs, when the first SMTC opportunity, indicated by opportunity X, becomes unavailable due to LBT failure and / or beam misalignment, SR1_intra (or SR1_inter) is set to 1. Between opportunities X+N and X+2*N-1, if one or more unavailable SMTC opportunities exist, SR1_intra (or SR1_inter) is incremented by 1 (i.e., set to 2). This process can continue for other SMTC opportunities that become unavailable.

[0053] Option 2 – In this example, for cells within an unknown frequency range:

[0054] T search = (N*Trs+J*L_intra*Trs)ms formula (4).

[0055] For unknown frequency cells

[0056] T search = (N*3*Trs+K*L_inter*Trs)ms formula (5).

[0057] Here, L_intra and L_inter are the number of SMTC opportunities that are unavailable at UE105 during the intra-frequency detection period and inter-frequency detection period, respectively. Additionally, J and K are numbers not less than 1 and not greater than N.

[0058] Alternatively, when considering LBT failure and RX beam scanning for determining the interruption time, the following options can be used to determine T. IU .

[0059] Option 1 – in this example :

[0060] T IU= (1+L1)*T SSB,RO +10ms formula (6).

[0061] Here, T SSB,RO This is the SSB to PRACH timing correlation period. Based on some examples, T... SSB,RO Defined in Table 8.1-1 of TS 38.213, the full text of which is incorporated herein by reference. Additionally, L1 is the number of consecutive SSB-PRACH timing associated periods during which no PRACH timing is available for PRACH transmission due to an uplink (UL) LBT failure.

[0062] Option 2 – in this example :

[0063] T IU =T SSB,RO +L2*SMTC_periodicity+10ms formula (7).

[0064] Here, T SSB,RO It is the SSB to PRACH timing association period, as discussed above. In addition, L2 is the number of consecutive PRACH timing associations during which UE 105 is unable to transmit PRACH due to UL LBT failure.

[0065] According to some aspects, T interuption Formula (1) can be used and T can be obtained from formulas (2), (3), (4) or (5). search and T from formula (6) or (7) IU To determine.

[0066] According to some aspects, because of the search time T search The time interval between the two closest successful SSB measurements and / or detections in the time domain may become longer at the UE due to one or more LBT failures, one or more beam misalignments (e.g., the UE performs an RX beam scan), or a combination of LBT failures and beam misalignments. A time threshold for this time interval can be used. According to some examples, if the time interval between a previous successful measurement and the current successful measurement exceeds the time threshold, the UE 105 will discard the previous successful measurement (and any prior successful measurements). In other words, if the time interval between the two closest successful measurements exceeds the time threshold, the UE 105 will discard the previous measurement, and additionally, the UE 105 will reset the search time T. search And restart the calculation of search time T. search In some examples, the time threshold may be provided in the specifications used by UE 105 and the network (e.g., base stations 101 and 103). Alternatively or additionally, the network may signal the time threshold to UE 105.

[0067] Depending on some aspects, UE 105 can be configured to perform one or more of radio link monitoring (RLM), beam fault detection (BFD), or candidate beam detection (CBD) in system 100. In some examples, UE 105 can perform these operations on a channel associated with a serving cell (e.g., base station 101).

[0068] Based on some examples, and considering RLM, UE 105 can use its physical layer to monitor downlink (DL) radio link quality and transmit the measurements to the upper layer. UE 105 can use the media access control (MAC) layer for BFD and recovery. Additionally, UE 105 can use its RRC layer to configure the physical and / or MAC layers and perform radio link failure detection and / or RRC establishment (or reconstruction). According to some aspects, RLM can be based on different Radio Link Monitoring Reference Signal (RLM-RS) resources configured by the network (e.g., base stations 101 and / or 103).

[0069] According to some aspects, UE 105 may perform RLM, BFD, and / or CBD during evaluation time periods corresponding to RLM, BFD, and / or CBD operations, respectively. In the current TS 38.133, for FR2, UE 105 may be able to evaluate during the first evaluation time period (T... Evaluate_out_SSB Within [ms]), assess whether the downlink radio link quality on the configured RLM-RS resources is worse than that in the first assessment period (T). Evaluate_out_SSB The first threshold (e.g., Q) within [ms]) out_SSB Similarly, UE105 may be able to evaluate the second evaluation period (T). Evaluate_in_SSB The downlink radio link quality on the configured RLM-RS resources evaluated within [ms]) is better than that in the second evaluation period (T). Evaluate_in_SSB The second threshold (e.g., Q) within [ms]) in_SSB ), where the scaling factor N = 8. In this example, for FR2, the first and second evaluation periods can be determined using Table 8.1.2.2-2 of TS 38.133, which is incorporated herein in its entirety.

[0070] Similarly, in the current TS 38.133, for FR2, UE 105 may be able to assess during the third assessment period (T). Evaluate_BFD_SSB The downlink radio link quality on the configured SSB resources in the set evaluated within [ms]) is worse than that in the third evaluation period (T). Evaluate_BFD_SSB The third threshold (e.g., Q) within [ms]) out_LR_SSBIn this example, for FR2, the third evaluation period can be determined using Table 8.5.2.2-2 of TS 38.133, which is incorporated herein in its entirety.

[0071] Similarly, in the current TS 38.133, for FR2, UE 105 may be able to assess during the fourth assessment period (T Evaluate_CBD_SSB The L1-RSRP measurement on the configured SSB resources in the set evaluated within [ms]) is better than that in the fourth evaluation period (T). Evaluate_CBD_SSB The fourth threshold (e.g., Q) within [ms]) in_LR In this example, for FR2, the fourth evaluation period can be determined using Table 8.5.5.2-2 of TS38.133, which is incorporated herein in its entirety.

[0072] Some aspects of this disclosure relate to a first evaluation time period, a second evaluation time period, a third evaluation time period, and a fourth evaluation time period (e.g., T) when an LBT failure occurs and / or when an RX beam scan occurs. Evaluate_out_SSB [ms]、T Evaluate_in_SSB [ms]、T Evaluate_BFD_SSB [ms] and T Evaluate_CBD_SSB [ms]).

[0073] Based on some examples, the first evaluation period of RLM operation (e.g., T) when an LBT failure occurs and / or when an RX beam scan occurs. Evaluate_out_SSB [ms], now updated to T Evaluate_out_SSB,CCA [ms]) can be determined as follows:

[0074] T Evaluate_out_SSB,CCA =max(200,Ceil((10+Z1)*P*N)*T ssb ) formula (8).

[0075] Here, T ssb Similar to the T discussed above ssb,RO N is the RX beam scanning factor. P can be determined as discussed in TS 38.133, the entirety of which is incorporated herein by reference. Additionally, Z1 is determined based on, for example, different SSBs. The / Iot value can be set to a different integer.

[0076] In this example, considering LBT failure and RX beam scanning, the second evaluation time period (e.g., T) for RLM operation is... Evaluate_in_SSB [ms], now updated to T Evaluate_in_SSB,CCA [ms]) can be determined using different options.

[0077] Option 1 – The second evaluation period can be determined as follows: :

[0078] TEvaluate_in_SSB,CCA =max(100,Ceil((5+Z2)*P*N)*T ssb ) formula (9).

[0079] Here, Z2 is an integer that can be obtained in the same way as SR1_intra (or SR1_inter). In some examples, there may be an upper limit to Z2, denoted as Z2max.

[0080] Option 2 – The second evaluation period can be determined as follows: :

[0081] T Evaluate_in_SSB,CCA =max(100,(Ceil(5*P*N)+Z3)*Tssb) formula (10).

[0082] Here, Z3 is not less than due to the second evaluation period T Evaluate_in_SSB,CCA The integer number of times the RLM-RS SSB is unavailable at UE 105 due to an LBT failure at the base station.

[0083] According to some examples, for a 60 GHz spectrum, N in Equations 9 and 10 can exceed 8.

[0084] Based on some examples, the evaluation period for RLM operation can be determined in a similar manner to that discussed above for DRX cycles without DRX (discontinuous reception), DRX cycles less than or equal to 320ms, and / or DRX cycles greater than 320ms.

[0085] According to some aspects, because of the first and second evaluation periods of RLM (T Evaluate_out_SSB,CCA and T Evaluate_in_SSB,CCAThe time interval may be longer due to one or more LBT failures, one or more RX beam scans, or a combination of LBT failures and RX beam scans, so one or more thresholds can be used for the time period between the two closest successful SSB or CSI-RS measurements in the time domain. For example, a time interval threshold can be used during both the first and second evaluation time periods of the RLM. Alternatively, a first evaluation time interval threshold can be used during the first evaluation time period of the RLM, and a second evaluation time interval threshold can be used during the second evaluation time period of the RLM. A time interval threshold can be used during the first and / or second evaluation time periods between the two closest successful measurements performed by UE 105. According to some examples, if the time interval between a previous successful measurement and the current successful measurement exceeds a time interval threshold, UE 105 will discard the previous successful measurement (and any prior successful measurements) and also reset the evaluation time interval and restart the calculation of the evaluation time interval. In some examples, the time interval threshold may be provided in the specifications used by UE 105 and the network (e.g., base stations 101 and 103). Additionally or alternatively, the network may signal the evaluation time interval threshold to UE 105.

[0086] Although some aspects of this disclosure are discussed relative to the evaluation period of RLM operations, similar analyses and determinations can be applied to BFD and / or CBD operations.

[0087] For example, the third evaluation period of BFD operation (e.g., T) when an LBT failure occurs and / or when an RX beam scan occurs. Evaluate_BFD_SSB [ms], now updated to T Evaluate_BFD_SSB,CCA [ms]) can be determined as follows:

[0088] T Evaluate_BFD_SSB,CCA =max(200,Ceil((10+Z1)*P*N)*T ssb ) formula (11).

[0089] For example, during the fourth evaluation period of CBD operation (e.g., T) when an LBT failure occurs and / or when an RX beam scan occurs. Evaluate_CBD_SSB [ms] is now updated to T Evaluate_CBD_SSB,CCA [ms]) can be determined using different options.

[0090] Option 1 – The fourth assessment period can be determined as :

[0091] T Evaluate_CBD_SSB,CCA =max(100,Ceil((5+Z2)*P*N)*T ssb ) formula (12).

[0092] Option 2 – The second evaluation period can be determined as follows: :

[0093] T Evaluate_CBD_SSB,CCA =max(100,(Ceil(5*P*N)+Z3)*Tssb) Formula (13).

[0094] According to some aspects, because of the third and fourth assessment periods (T) of BFD and CBD Evaluate_BFD_SSB,CCA and T Evaluate_CBD_SSB,CCA The time interval may be longer due to one or more LBT failures, one or more RX beam scans, or a combination of LBT failures and RX beam scans, so one or more thresholds can be used for the time period between the two closest successful SSB or CSI-RS measurements in the time domain. For example, a time interval threshold can be used during both the third and fourth evaluation time periods of BFD and CBD. Similarly, a third time interval threshold can be used during the third evaluation time period of BFD, and a fourth time interval threshold can be used during the fourth evaluation time period of CBD. The time interval threshold can be used for the third and / or fourth evaluation time periods between the two closest successful measurements performed by UE 105. According to some examples, if the time interval between a previous successful measurement and the current successful measurement exceeds the time interval threshold, UE 105 will discard the previous successful measurement (and any prior successful measurements) and also reset the evaluation time interval and restart the calculation of the evaluation time interval. In some examples, the evaluation time interval threshold may be provided in the specification used by UE 105 and the network (e.g., base stations 101 and 103). Additionally or alternatively, the network may signal the evaluation time interval threshold to UE 105.

[0095] Figure 2 A block diagram of an exemplary system 200 of electronic equipment implementing some aspects of this disclosure for performing handover, RLM, BFD, and CBD in unlicensed spectrum in the event of an LBT failure and / or while the UE is performing an RX beam scan is shown. System 200 may be any electronic equipment of system 100 (e.g., base station 101, 103, UE 105). System 200 includes a processor 210, one or more transceivers 220a-220n, communication infrastructure 240, memory 250, operating system 252, application program 254, and antenna 260. The illustrated system is provided as an exemplary part of system 200, and system 200 may include other circuitry and subsystems. Furthermore, although the system of system 200 is shown as separate components, aspects of this disclosure may include any combination of these components, fewer components, or more components.

[0096] Memory 250 may include random access memory (RAM) and / or cache, and may include control logic (e.g., computer software) and / or data. Memory 250 may include other storage devices or memories, such as, but not limited to, hard disk drives and / or removable storage devices / cells. According to some examples, operating system 252 may be stored in memory 250. Operating system 252 may manage data transfer from memory 250 and / or one or more applications 254 to processor 210 and / or one or more transceivers 220a-220n. In some examples, operating system 252 may hold one or more network protocol stacks (e.g., Internet Protocol stack, cellular protocol stack, etc.) that may include multiple logical layers. At the corresponding layer of the protocol stack, operating system 252 includes control mechanisms and data structures to perform the functions associated with that layer.

[0097] According to some examples, application 254 may be stored in memory 250. Application 254 may include applications used by users of wireless system 200 and / or users of wireless system 200 (e.g., user applications). Applications in application 254 may include, but are not limited to, applications such as, but not limited to, audio calls, video calls, radio streams, video streams, remote control, and / or other user applications.

[0098] System 200 may also include communication infrastructure 240. Communication infrastructure 240 provides communication between, for example, processor 210, one or more transceivers 220a-220n, and memory 250. In some implementations, communication infrastructure 240 may be a bus. Processor 210, together with instructions stored in memory 250, executes to enable system 200 of system 100 to implement mechanisms for performing handover, RLM, BFD, and CBD in unlicensed spectrum during LBT failure and / or when the UE performs RX beam scanning, as described herein.

[0099] According to some aspects, one or more transceivers 220a-220n transmit and receive communication signals supporting mechanisms for performing handover, RLM, BFD, and CBD in unlicensed spectrum during LBT failure and / or when the UE performs RX beam scanning, and may be coupled to antenna 260. Antenna 260 may include one or more antennas that may be the same or different types. One or more transceivers 220a-220n allow system 200 to communicate with other devices that may be wired and / or wireless. In some examples, one or more transceivers 220a-220n may include processors, controllers, radio components, sockets, plugs, buffers, and similar circuitry / devices for connecting to and communicating over a network. According to some examples, one or more transceivers 220a-220n may include one or more circuitry for connecting to and communicating over wired and / or wireless networks.

[0100] According to some aspects, one or more transceivers 220a-220n may include a cellular subsystem, a WLAN subsystem, and / or Bluetooth. TM The subsystems each include their own radio transceivers and protocols, as those skilled in the art will understand based on the discussion provided herein. In some specific implementations, one or more transceivers 220a-220n may include more or fewer systems for communicating with other devices.

[0101] In some examples, one or more transceivers 220a-220n may include one or more circuits (including a WLAN transceiver) for enabling connectivity and communication via a WLAN network (such as, but not limited to, networks based on the standards described in IEEE 802.11). Alternatively, one or more transceivers 220a-220n may include circuits for enabling, for example, Bluetooth-based... TM Protocol, Bluetooth TM Low power protocol or Bluetooth TM One or more circuits for low-power remote protocol connectivity and communication (including Bluetooth) TM (Transceiver). For example, transceiver 220n may include Bluetooth. TM Transceiver.

[0102] Additionally, one or more transceivers 220a-220n may include one or more circuits (including cellular transceivers) for connecting to and communicating over a cellular network. Cellular networks may include, but are not limited to, 3G / 4G / 5G networks, such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), etc. For example, one or more transceivers 220a-220n may be configured to operate according to one or more of the 3GPP standards Rel-15, Rel-16, Rel-17, or later versions.

[0103] According to some aspects, processor 210 (alone or in combination with computer instructions stored in memory 250) and / or one or more transceivers 220a-220n implement mechanisms for performing handover, RLM, BFD, and CBD in unlicensed spectrum in the event of an LBT failure and / or when the UE performs an RX beam scan, as discussed herein. For example, transceiver 220a may be able to perform handover, RLM, BFD, and CBD via a first carrier (e.g., Figure 1 The carrier 107) enables connection and communication. In this example, transceiver 220a and / or transceiver 220b enable the detection and / or measurement of the second carrier (e.g., carrier 107). Figure 1 (Carrier 109). Additionally, or alternatively, the wireless system 200 may include a transceiver configured to operate on different carriers. According to some examples, the processor 210 may be configured to control a transceiver to switch between different carriers. While the operations discussed herein are relative to processor 210, it should be noted that processor 210 may perform these operations alone or in combination with computer instructions stored in memory 250 and / or one or more transceivers 220a-220n.

[0104] Figure 3 An exemplary method 300 is shown for a system (e.g., a UE) according to some aspects of this disclosure to support mechanisms for performing handover, RLM, BFD, and CBD in unlicensed spectrum in the event of an LBT failure and / or while the UE is performing an RX beam scan. For convenience, and not limitation, reference may be made to... Figures 1 to 2 Element description Figure 3 Method 300 may represent electronic devices (e.g., Figure 1 The implementation of UE 105) is used to operate mechanisms for performing handover, RLM, BFD, and CBD in unlicensed spectrum when an LBT failure occurs and / or when the UE is performing an RX beam scan. Method 300 can also be implemented by... Figure 2 System 200 and / or Figure 5 The method is executed by computer system 500. However, method 300 is not limited to the specific aspects depicted in the figures, and other systems may be used to execute the method, as those skilled in the art will understand. It should be understood that not all operations may be required, and these operations may not be compatible with... Figure 3 Perform them in the same order as shown.

[0105] At 302, a handover command is received. For example, UE 105 may receive a handover command from the serving cell (e.g., base station 101) for connecting to the target cell (e.g., base station 103). Alternatively, UE 105 may receive a handover command from the target cell (e.g., base station 103). At 304, in response to the handover command, a handover procedure is initiated. For example, UE 105 may initiate a handover procedure to connect from the serving cell to the target cell. As discussed above, operations 302 and 304 may be (or include) a UE-initiated handover, a network-initiated handover, an intra-frequency handover, and / or an inter-frequency handover.

[0106] At 306, it is determined whether a Listen-Before-Speak (LBT) fault has occurred and / or whether the UE is about to perform beam scanning operation due to beam misalignment. For example, the UE (e.g., UE 105) determines that an LBT fault has occurred at the base station (e.g., base station 101) or that the UE's RX beam is misaligned with the base station's TX beam (beam misalignment). According to some examples, when the UE cannot successfully detect an SSB transmitted by the base station, UE 105 may determine that an LBT fault has occurred at the base station or that the RX beam is misaligned with the base station's TX beam. As another example, the UE (e.g., UE 105) operates on unlicensed spectrum and, as discussed above, performs LBT operation (e.g., using CCA) before using the channel. In some aspects, if, for example, during CCA operation, the UE detects energy above a threshold on the channel, the UE may determine that an LBT fault has occurred.

[0107] Additionally, depending on certain aspects, when the UE detects beam misalignment, it can determine that it will perform a beam scanning operation. In a non-limiting example, if the UE does not know which beam it will use to receive, for example, an SSB from the serving cell, it can determine that it will perform a beam scanning operation. By performing a beam scanning operation, the UE can determine the "optimal" beam for receiving information and data from the serving cell.

[0108] During a handover procedure initiated via a handover command and in response to an LBT failure and / or the UE performing a beam scan operation, operation 306 may further include determining search time and interruption time uncertainties. In other words, if the UE determines that an LBT failure has occurred and / or the UE is about to perform a beam scan operation, the UE may determine the search time and interruption time uncertainties as discussed above (e.g., using formulas (2), (3), (4) or (5)).

[0109] For example, the search time can be determined based at least on: (1) the number of unavailable SMTC opportunities, or (2) the number of SMTC opportunities on which the UE does not detect any SSB during an in-frequency detection period or an inter-frequency detection period. Alternatively or additionally, the interruption time uncertainty can be determined based on (1) the number of consecutive SSB-PRACH opportunity associated periods during which no PRACH opportunity is available for PRACH transmission, or (2) the number of consecutive PRACH opportunities during which the UE cannot perform PRACH transmission.

[0110] At 308, the handover delay is determined based on the uncertainty of the search time and the interruption time. For example, the UE can use the determined search time and the interruption time uncertainty to determine the handover delay in, for example, Equation (1), as discussed above.

[0111] At 310, a handover delay is used to determine whether to continue or stop the handover procedure. For example, the UE may measure and maintain a time period for the handover procedure. In some examples, the handover procedure time period may begin from the time the UE receives the handover command from the target cell. However, aspects of this disclosure may include other times for the time period used to start the handover procedure based on the type of handover. If the handover procedure time period exceeds the handover delay, the UE may stop the handover procedure. In some examples, the UE may actively stop the handover procedure for purposes such as power saving. Alternatively or additionally, the UE may continue the handover procedure until the corresponding handover timer (e.g., T304) expires. In some examples, the UE will stop the handover procedure and initiate an RRC connection reconstruction procedure after the handover time expires. Alternatively or additionally, the UE may be further configured to rebuild the connection with the serving cell or establish a connection with the target cell or a third cell in response to the time period used to perform the handover procedure exceeding the handover delay.

[0112] Method 300 may further include comparing the time interval between the two nearest successful measurements during the search time with a time threshold. The time interval between the two nearest successful measurements may include the time interval between the two nearest successful SSB measurements and / or detections in the time domain (e.g., temporally consecutive – no other successful measurements between these two). Method 300 may further include resetting the search time and redetermining the search time in response to the time interval between the two nearest successful measurements exceeding the time threshold. For example, the UE may measure and store the time interval between a previous successful measurement and a current successful measurement. The UE may determine whether the time interval between the previous successful measurement and the current successful measurement exceeds the time threshold. If the time interval between the previous successful measurement and the current successful measurement exceeds the time threshold, the UE may discard the previous measurement, and the UE resets the search time and restarts the calculation of the search time.

[0113] According to some aspects, the UE can operate on unlicensed spectrum in the 52.6 GHz to 71 GHz range as part of Frequency Range 2 (FR2).

[0114] Although the above discussion relates to the switching procedure Figure 3 Method 300 can be used, but similar operations can be performed relative to the RLM, BFD, and CBD procedures. RLM, BFD, and CBD procedures, taking into account LBT failures and / or RX beam scanning, can be performed as a supplement to or alternative to the switching procedure.

[0115] Figure 4 Another exemplary method 400 is shown for a system (e.g., a UE) according to some aspects of this disclosure to support mechanisms for performing handover, RLM, BFD, and CBD in unlicensed spectrum in the event of an LBT failure and / or while the UE is performing an RX beam scan. For convenience, and not limitation, please contact Figures 1 to 3 Element description Figure 4 Method 400 may represent electronic devices (e.g., Figure 1 The implementation of UE 105) is used to operate mechanisms for performing handover, RLM, BFD, and CBD in unlicensed spectrum when an LBT failure occurs and / or when the UE is performing an RX beam scan. Method 400 can also be implemented by... Figure 2 System 200 and / or Figure 5 The method is executed by computer system 500. However, method 400 is not limited to the specific aspects depicted in the figures, and other systems may be used to execute the method, as those skilled in the art will understand. It should be understood that not all operations may be necessary, and these operations may not be compatible with... Figure 4 Execute in the same order as shown. Method 400 can be used as... Figure 3 Method 300 can be used as a supplement or alternative.

[0116] At 402, an evaluation period for Radio Link Monitoring (RLM), Beam Failure Detection (BFD), and / or Candidate Beam Detection (CBD) is determined. For example, the UE (e.g., UE 105) may determine a first evaluation period for the RLM procedure, a second evaluation period for the BFD procedure, and / or a third evaluation period for the CBD procedure. Depending on some aspects, the first, second, and third evaluation periods may be the same time period for two or more of the RLM, BFD, and CBD procedures. Alternatively, the first, second, and third evaluation periods may be different time periods for two or more of the RLM, BFD, and CBD procedures.

[0117] The UE determines these assessment time periods based on LBT failure or when the UE performs beam scanning operations. For example, similar to Figure 3In operation 306, the UE determines whether an LBT failure has occurred and / or whether the UE is about to perform a beam scan operation. During a handover procedure initiated by a handover command and in response to an LBT failure or the UE performing a beam scan operation, the UE may determine the evaluation period for the RLM, BFD, and / or CBD procedures. As discussed above, the UE may use formulas (8)-(13) to determine the evaluation period for the RLM, BFD, and / or CBD procedures, depending on several aspects.

[0118] At position 404, the evaluation time period is used for RLM, BFD, and / or CBD procedures. For example, when the UE performs one or more RLM, BFD, or CBD procedures, the UE uses the determined evaluation time period to perform the corresponding operation.

[0119] Depending on several factors, the evaluation period can be used to determine whether to continue or stop an RLM, BFD, or CBD procedure. For example, the UE can measure and maintain the time period for an RLM, BFD, or CBD procedure. If the time period used to perform the RLM, BFD, or CBD procedure exceeds the evaluation period, the UE can stop the RLM, BFD, or CBD procedure. Alternatively or additionally, the UE can be further configured to restart the RLM, BFD, or CBD procedure in response to the time period between the two closest successful measurements exceeding the time period threshold during an RLM, BFD, or CBD procedure exceeding the time period threshold.

[0120] In 406 and 408, the UE may reset the evaluation time period if the time interval between the two closest successful measurements during the evaluation time period exceeds one or more thresholds. For example, in 406, the time interval between the two closest successful measurements during the evaluation time period is compared with a threshold. In some examples, the time interval between the two closest successful measurements is the time interval between the two closest successful SSB or CSI-RS (Channel State Information Reference Signal) measurements and / or detections in the time domain. According to some aspects, the UE will have a successful SSB measurement and / or detection when the base station (BS) transmits an SSB and the BS SSB TX beam and the UE RX beam are aligned. In some examples, the two closest successful measurements in time are two consecutive successful measurements in time (e.g., no other successful measurements between these two). According to some aspects, the threshold for the evaluation time period may be the same threshold for two or more of the RLM, BFD, and CBD procedures. Alternatively, the threshold for the evaluation time period may be different thresholds for two or more of the RLM, BFD, and CBD procedures.

[0121] In step 408, and in response to the time interval between the two closest successful measurements exceeding a threshold, the evaluation time interval can be reset and redefined.

[0122] One or more computer systems (such as...) can be used, for example. Figure 5 The computer system 500 shown herein is used to implement various aspects. The computer system 500 can be any well-known computer capable of performing the functions described herein, such as... Figure 1 Devices 101, 105 and / or Figure 2 The device 200. The computer system 500 includes one or more processors (also referred to as a central processing unit or CPU), such as processor 504. Processor 504 is connected to communication infrastructure 506 (e.g., a bus). The computer system 500 also includes user input / output devices 503, such as a monitor, keyboard, pointing device, etc., that communicate with the communication infrastructure 506 via user input / output interface 502. The computer system 500 also includes main memory or primary memory 508, such as random access memory (RAM). Main memory 508 may include one or more levels of cache. Main memory 508 stores control logic components (e.g., computer software) and / or data.

[0123] The computer system 500 may also include one or more auxiliary storage devices or memories 510. Auxiliary storage 510 may include, for example, a hard disk drive 512 and / or a removable storage device or drive 514. The removable storage drive 514 may be a floppy disk drive, tape drive, optical disk drive, optical storage device, tape backup device, and / or any other storage device / drive.

[0124] Removable storage drive 514 can interact with removable storage unit 518. Removable storage unit 518 includes a computer-usable or readable storage device on which computer software (control logic components) and / or data are stored. Removable storage unit 518 can be a floppy disk, magnetic tape, optical disc, DVD, optical storage disk, and / or any other computer data storage device. Removable storage drive 514 reads from and / or writes to removable storage unit 518 in a well-known manner.

[0125] According to some aspects, auxiliary storage 510 may include other means, tools, or other methods for allowing computer programs and / or other instructions and / or data to be accessed by computer system 500. Such means, tools, or other methods may include, for example, removable storage unit 522 and interface 520. Examples of removable storage unit 522 and interface 520 may include program boxes and box interfaces (such as those found in video game devices), removable memory chips (such as EPROM or PROM) and associated sockets, memory sticks and USB ports, memory cards and associated memory card slots, and / or any other removable storage unit and associated interface.

[0126] Computer system 500 may also include a communication or network interface 524. Communication interface 524 enables computer system 500 to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively referred to by reference numeral 528). For example, communication interface 524 may allow computer system 500 to communicate with remote device 528 via communication path 526, which may be wired and / or wireless, and may include any combination of LAN, WAN, Internet, etc. Control logic components and / or data may be transmitted to and from computer system 500 via communication path 526.

[0127] The operations described in the foregoing aspects can be implemented in various configurations and architectures. Therefore, some or all of the operations described in the foregoing aspects can be performed in hardware, software, or both. In some aspects, tangible, non-transitory devices or articles of art include tangible, non-transitory computer-usable or readable media on which control logic components (software) are stored, also referred to herein as computer program products or program storage devices. This includes, but is not limited to, computer system 500, main memory 508, secondary memory 510, and removable storage units 518 and 522, and tangible articles embodying any combination thereof. Such control logic components, when executed by one or more data processing devices (such as computer system 500), cause such data processing devices to operate as described herein.

[0128] Based on the teachings contained in this disclosure, it will be apparent to those skilled in the art how to use [other methods]. Figure 5 Other data processing devices, computer systems, and / or computer architectures besides those shown may be used to make and use aspects of this disclosure. In particular, aspects may operate in conjunction with software, hardware, and / or operating system implementations other than those described herein.

[0129] It should be understood that the Detailed Description section, rather than the Summary and Abstract section, is intended to be used to interpret the claims. The Summary and Abstract section may set forth one or more, but not all, exemplary aspects of this disclosure as contemplated by the inventors, and is therefore not intended to limit this disclosure or the appended claims in any way.

[0130] Although this disclosure has been described herein with reference to exemplary aspects of exemplary fields and applications, it should be understood that this disclosure is not limited thereto. Other aspects and modifications are possible and are within the scope and spirit of this disclosure. For example, and without limiting the generality of this paragraph, the aspects are not limited to the software, hardware, firmware, and / or entities shown in the figures and / or described herein. Furthermore, the aspects (whether explicitly described herein or not) have significant utility for fields and applications beyond those described herein.

[0131] The aspects have been described here using functional building blocks that illustrate specific implementations of functions and their relationships. For ease of description, the boundaries of these functional building blocks have been arbitrarily defined herein. Alternative boundaries may be defined as long as the specified functions and relationships (or their equivalents) are performed appropriately. Furthermore, alternative aspects may perform functional blocks, steps, operations, methods, etc., in an order different from that described herein.

[0132] References to “an aspect,” “aspect,” “an example,” “example,” or similar phrases herein indicate that the aspect described may include a particular feature, structure, or characteristic, but each aspect may not necessarily include that particular feature, structure, or characteristic. Furthermore, such wording does not necessarily refer to the same aspect. Additionally, when a particular feature, structure, or characteristic is described in conjunction with an aspect, whether or not it is explicitly mentioned or described herein, the combination of those features, structures, or characteristics with other aspects is within the knowledge of a person skilled in the art.

[0133] The breadth and scope of this disclosure should not be limited by any of the foregoing exemplary aspects, but should be defined solely by the following claims and their equivalents.

[0134] This disclosure assumes that entities responsible for collecting, analyzing, disclosing, transmitting, storing, or otherwise using such personal information data will comply with established privacy policies and / or privacy practices. Specifically, such entities should implement and adhere to privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy and security of personal information data. Such policies should be easily accessible to users and should be updated as data collection and / or use change. Personal information from users should be collected for the entity's lawful and reasonable purposes and not shared or sold outside of these lawful uses. Furthermore, such collection / sharing should only occur upon receiving informed consent from users. In addition, such entities should consider taking any necessary steps to protect and safeguard access to such personal information data and ensure that others with access to such personal information data comply with their privacy policies and processes. Additionally, such entities may be subject to third-party evaluations to demonstrate their compliance with widely accepted privacy policies and practices. Furthermore, policies and practices should be adapted to the specific types of personal information data collected and / or accessed, and to applicable laws and standards, including specific considerations regarding jurisdiction. For example, in the United States, the collection or access to certain health data may be governed by federal and / or state laws, such as the Health Insurance Transfer and Accountability Act (HIPAA); while in other countries, health data may be subject to other regulations and policies and should be handled accordingly. Therefore, different privacy practices should be maintained for different types of personal data in each country.

Claims

1. A user equipment (UE), comprising: a transceiver configured to wirelessly communicate with a serving cell; and a processor communicatively coupled to the transceiver and configured to: receive, using the transceiver, a handover command for connecting to a target cell; initiate a handover procedure in response to the handover command; determine a search time and an interruption time uncertainty in response to a listen-before-talk (LBT) failure or the UE performing a beam sweep operation during the handover procedure; determine a handover delay based on the search time and the interruption time uncertainty; stop the handover procedure in response to a time period for performing the handover procedure exceeding the handover delay; determine an evaluation time period for radio link monitoring (RLM) based on the LBT failure or the UE performing the beam sweep operation; perform RLM operations using the evaluation time period; compare a time period between two closest successful measurements to a threshold value; and reset the evaluation time period and redetermine the evaluation time period in response to the time period between two closest successful measurements exceeding the threshold value.

2. The UE of claim 1, wherein the processor is further configured to reestablish a connection with the serving cell or establish a connection with the target cell or a third cell in response to the time period for performing the handover procedure exceeding the handover delay.

3. The UE of claim 1, wherein the processor is further configured to determine the search time based on at least (1) a number of synchronization signal block (SSB) based measurement timing configuration (SMTC) occasions that are unavailable or (2) a number of SMTC occasions on which the UE does not detect any SSBs during an intra- frequency detection period or an inter- frequency detection period.

4. The UE of claim 1, wherein the processor is further configured to determine the interruption time uncertainty based on (1) a number of consecutive synchronization signal block (SSB) to physical random access channel (PRACH) occasion periods during which no PRACH occasion is available for a PRACH transmission or (2) a number of consecutive PRACH occasions during which the UE cannot make a PRACH transmission.

5. The UE of claim 1, wherein the processor is further configured to: compare a second time period between two closest successful measurements during the search time to a time threshold value; and reset the search time and redetermine the search time in response to the second time period between two closest successful measurements exceeding the time threshold value.

6. The UE of claim 1, wherein the processor is further configured to: determine a second evaluation time period for beam failure detection (BFD) based on the LBT failure or the UE performing the beam sweep operation; perform BFD operations using the second evaluation time period; compare a second time period between two closest successful measurements to a second threshold value; and reset the second evaluation time period and redetermine the second evaluation time period in response to the second time period between two closest successful measurements exceeding the second threshold value. ​ resetting the second evaluation period and re-determining the second evaluation period in response to the second time period between two closest successful measurements exceeding the second threshold.

7. The UE of claim 1, wherein the processor is further configured to: determine a second evaluation period for candidate beam detection (CBD) based on the LBT failure or the UE performing the beam sweep operation; perform CBD operation using the second evaluation period; compare a second time period between two closest successful measurements to a second threshold; and reset the second evaluation period and re-determine the second evaluation period in response to the second time period between two closest successful measurements exceeding the second threshold.

8. The UE of claim 1, wherein the transceiver is configured to operate on an unlicensed spectrum as part of frequency range 2 (FR2) in a 52.6 GHz to 71 GHz spectrum.

9. A method for performing a handover, comprising: receiving, by a user equipment (UE), a handover command for connecting to a target cell; initiating, in response to the handover command, a handover procedure; determining, during the handover procedure, a search time and an interruption time uncertainty in response to a listen-before-talk (LBT) failure or the UE performing a beam sweep operation; determining a handover delay based on the search time and the interruption time uncertainty; stopping the handover procedure in response to a time period for performing the handover procedure exceeding the handover delay; determining an evaluation period for radio link monitoring (RLM) based on the LBT failure or the UE performing the beam sweep operation; performing RLM operation using the evaluation period; comparing a time period between two closest successful measurements to a threshold; and resetting the evaluation period and re-determining the evaluation period in response to the time period between two closest successful measurements exceeding the threshold.

10. The method of claim 9, further comprising: re-establishing a connection with a serving cell or establishing a connection with the target cell or a third cell in response to the time period for performing the handover procedure exceeding the handover delay.

11. The method of claim 9, wherein the determining the search time comprises determining the search time based on at least: (1) a number of synchronization signal block (SSB) based measurement timing configuration (SMTC) occasions that are unavailable, or (2) a number of SMTC occasions on which the UE does not detect any SSBs during an intra- frequency detection period or an inter- frequency detection period.

12. The method of claim 9, wherein the determining the interruption time uncertainty comprises determining the interruption time uncertainty based on at least: (1) a number of consecutive synchronization signal block (SSB) to physical random access channel (PRACH) occasion periods during which no PRACH occasions are available for PRACH transmission, or (2) a number of consecutive PRACH occasions during which the UE cannot make PRACH transmissions.

13. The method of claim 9, further comprising: ​ comparing a second time period between two closest successful measurements during the search time to a second time threshold; and in response to the second time period between two closest successful measurements exceeding the second time threshold, resetting the search time and re-determining the search time.

14. The method of claim 9, further comprising: determining a second evaluation time period for beam failure detection (BFD) based on the LBT failure or the UE performing the beam sweeping operation; performing BFD operation using the second evaluation time period; comparing a second time period between two closest successful measurements to a second threshold; and in response to the second time period between two closest successful measurements exceeding the second threshold, resetting the second evaluation time period and re-determining the second evaluation time period.

15. The method of claim 9, further comprising: determining a second evaluation time period for candidate beam detection (CBD) based on the LBT failure or the UE performing the beam sweeping operation; performing CBD operation using the second evaluation time period; comparing a second time period between two closest successful measurements to a second threshold; and in response to the second time period between two closest successful measurements exceeding the second threshold, resetting the second evaluation time period and re-determining the second evaluation time period.

16. A non-transitory computer-readable medium storing instructions that, when executed by a processor of a user equipment (UE), cause the processor to perform operations comprising: receiving a handover command for connecting to a target cell; in response to the handover command, initiating a handover procedure; in response to a listen-before-talk (LBT) failure or the UE performing a beam sweeping operation during the handover procedure, determining a search time and an interruption time uncertainty; determining a handover delay based on the search time and the interruption time uncertainty; in response to a time period for performing the handover procedure exceeding the handover delay, stopping the handover procedure or continuing the handover procedure until a corresponding handover timer expires; determining an evaluation time period for radio link monitoring (RLM) based on the LBT failure or the UE performing the beam sweeping operation; performing RLM operation using the evaluation time period; comparing a time period between two closest successful measurements to a threshold; and in response to the time period between two closest successful measurements exceeding the threshold, resetting the evaluation time period and re-determining the evaluation time period.

17. The non-transitory computer-readable medium of claim 16, wherein the determining the search time comprises determining the search time based on at least (1) a number of synchronization signal block (SSB) based measurement timing configuration (SMTC) occasions that are unavailable or (2) a number of SMTC occasions on which the UE does not detect any SSBs during an intra-frequency detection period or an inter-frequency detection period.

18. The non-transitory computer-readable medium of claim 16, wherein the determining the interruption time uncertainty comprises determining the interruption time uncertainty based at least on: (1) a number of consecutive synchronization signal block (SSB)-to-physical random access channel (PRACH) occasion associations for which no PRACH occasion is available for a PRACH transmission, or (2) a number of consecutive PRACH occasions for which the UE cannot make a PRACH transmission.

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