WO2024060283A1

WO2024060283A1 - Methods and apparatuses for measurement configuration and failure recovery for uav ue

Info

Publication number: WO2024060283A1
Application number: PCT/CN2022/122485
Authority: WO
Inventors: Jing HAN; Haiming Wang; Lianhai WU; Min Xu; Ran YUE
Original assignee: Lenovo (Beijing) Limited
Priority date: 2022-09-29
Filing date: 2022-09-29
Publication date: 2024-03-28

Abstract

The present application relates to methods and apparatuses for methods and apparatuses for measurement configuration and failure recovery for unmanned aerial vehicle (UAV) user equipment (UE). One embodiment of the present disclosure provides a user equipment (UE), comprising: a transceiver; and a processor coupled with the transceiver and configured to: determine whether one or more conditions associated with movement of the UE are fulfilled; and perform at least one of the following in the case that at least one of the one or more conditions is fulfilled: transmit a first indication indicating that at least one of the one or more conditions is fulfilled; adjust a measurement configuration; apply a fast beam failure detection (BFD) configuration; skip a beam failure recovery (BFR) procedure; or enable a quick radio link failure (RLF) procedure.

Description

METHODS AND APPARATUSES FOR MEASUREMENT CONFIGURATION AND FAILURE RECOVERY FOR UAV UE

TECHNICAL FIELD

The present disclosure relates to wireless communication, and particularly relates to methods and apparatuses for measurement configuration and failure recovery for unmanned aerial vehicle (UAV) user equipment (UE) .

BACKGROUND OF THE INVENTION

When an aerial UE (e.g., a UAV UE, hereinafter in the present discourse, the term "UAV UE" is used) , flies in the sky, the path loss, or line of sight (LOS) path loss between the UAV UE and the neighbor cells may be very small. The UAV UE may not only receive strong signals from many neighbor cells, but may also be strong interference to neighbor cells (because the transmission from the UAV UE is also strong) . In order to detect such a case (s) , the BS may configure a measurement (s) for the UAV UE and determine the case (s) according to reported measurement results from the UAV UE.

However, an UAV UE may fly in an ascending direction or descending direction, i.e., the UAV UE may move in the vertical direction at a relatively high speed.

In this scenario, a current measurement configuration may not be adaptable, and, it is desirable to provide solutions for measurement configuration and failure recovery for the UAV UE.

SUMMARY

One embodiment of the present disclosure provides a user equipment (UE) , comprising: a transceiver; and a processor coupled with the transceiver and configured to: determine whether one or more conditions associated with movement of the UE are fulfilled; and perform at least one of the following in the case that at least one of the one or more conditions is fulfilled: transmit a first indication indicating that at least one of the one or more conditions is fulfilled; adjust a measurement configuration; apply a fast beam failure detection (BFD) configuration; skip a beam failure recovery (BFR) procedure; or enable a quick radio link failure (RLF) procedure.

In some embodiments, the processor is further configured to: receive a second indication indicating the UE to perform at least one of the following: adjust the measurement configuration; apply the fast BFD configuration; skip the BFR procedure; or enable the quick RLF procedure.

In some embodiments, the one or more conditions associated with movement of the UE include at least one of the following: a measurement event associated with a height of the UE being triggered; a height of the UE being higher than a first configured height threshold; a height of the UE being lower than a second configured height threshold; a time duration in which the event associated with a height of the UE is triggered being longer than a first time threshold; a time duration in which the height of the UE is higher than the first configured height threshold being longer than a second time threshold; a time duration in which the height of the UE is lower than the second configured height threshold being longer than a third time threshold; a vertical speed of the UE being higher than a vertical speed threshold; a vertical acceleration of the UE being higher than a vertical acceleration threshold; an average vertical speed of the UE during a time duration being higher than an average vertical speed threshold during a time duration; an average acceleration speed of the UE during a time duration being higher than an average vertical acceleration threshold during a time duration; a total number of changed beams or changed cells during a time duration being higher than a threshold associated with a total number of changed beams or changed cells during a time duration; or a height variation of the UE during a time duration being higher than a height variation threshold.

In some embodiments, the measurement configuration is associated with at least one of the following: a consolidation threshold; a maximum number of consolidation beams; a beam associated with a highest cell measurement result; a trigger event threshold; a report amount; a time to trigger (TTT) configuration; or a measurement object and report configuration.

In some embodiments, the fast BFD configuration includes a timer for beam failure detection and a maximum number for beam failure instances.

In some embodiments, in the case that a total number of a beam failure indication exceeds a maximum threshold for beam failure indication and BFR skip is enabled, the processor is further configured to: skip the BFR procedure and declare an RLF.

In some embodiments, the processor is further configured to: start a timer for the quick RLF procedure in the case that timer T310 is running or an N310 out-of-synchronization indication is received.

In some embodiments, the processor is further configured to: declare an RLF when the timer for the quick RLF procedure expires.

Another embodiment of the present disclosure provides a base station (BS) , comprising: a transceiver; and a processor coupled with the transceiver and configured to: receive, from a UE, a first indication indicating that at least one of the one or more conditions is fulfilled; and transmit, to the UE, a second indication indicating the UE to perform at least one of the following: adjust a measurement configuration; apply a fast BFD configuration; skip a BFR procedure; or enable a quick RLF procedure.

Yet another embodiment of the present disclosure provides a method performed by a UE, comprising: determining whether one or more conditions associated with movement of the UE are fulfilled; and performing at least one of the following in the case that at least one of the one or more conditions is fulfilled: transmitting a first indication indicating that at least one of the one or more conditions is fulfilled; adjusting a measurement configuration; applying a fast BFD configuration; skipping a BFR procedure; or enabling a quick RLF procedure.

In some embodiments, the method further comprising: receiving a second indication indicating the UE to perform at least one of the following: adjusting the measurement configuration; applying the fast BFD configuration; skipping the BFR procedure; or enabling the quick RLF procedure.

In some embodiments, the measurement configuration is associated with at least one of the following: a consolidation threshold; a maximum number of consolidation beams; a beam associated with a highest cell measurement result; a trigger event threshold; a report amount; a TTT configuration; or a measurement object and report configuration.

In some embodiments, the method further comprising: starting a timer for the quick RLF procedure in the case that timer T310 is running or an N310 out-of-synchronization indication is received.

In some embodiments, the method further comprising: declaring an RLF when the timer for the quick RLF procedure expires.

Still another embodiment of the present disclosure provides a method performed by a base station (BS) , comprising: receiving, from a UE, a first indication indicating that at least one of the one or more conditions is fulfilled; and transmitting, to the UE, a second indication indicating the UE to perform at least one of the following: adjusting a cell measurement configuration; applying a fast BFD configuration; skipping a BFR procedure; or enabling a quick RLF procedure.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which advantages and features of the application can be obtained, a description of the application is rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. These drawings depict only example embodiments of the application and are not therefore to be considered limiting of its scope.

Fig. 1 illustrates a schematic diagram of a wireless communication system according to some embodiments of the present disclosure.

Fig. 2 illustrates a measurement model according to some embodiments of the present disclosure.

Fig. 3 illustrates a method for fast BFD and BFR skipping according to some embodiments of the present disclosure.

Fig. 4 describes a method for a quick RLF procedure according to some embodiments of the present disclosure.

Fig. 5 illustrates a method performed by a UE for wireless communication according to some embodiments of the present disclosure.

Fig. 6 illustrates a method performed by a BS for wireless communication according to some embodiments of the present disclosure.

Fig. 7 illustrates a simplified block diagram of an apparatus according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of the currently preferred embodiments of the present invention, and is not intended to represent the only form in which the present invention may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present invention.

While operations are depicted in the drawings in a particular order, persons skilled in the art will readily recognize that such operations need not be performed in the particular order as shown or in a sequential order, or that all illustrated operations need be performed, to achieve desirable results; sometimes one or more operations can be skipped. Further, the drawings can schematically depict one or more example processes in the form of a flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In certain circumstances, multitasking and parallel processing can be advantageous.

Reference will now be made in detail to some embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architecture and new service scenarios, such as a cellular telephone network, a time division multiple access (TDMA) -based network, a code division multiple access (CDMA) -based network, an orthogonal frequency division multiple access (OFDMA) -based network, a LTE network, a 3 ^rd generation partnership project (3GPP) -based network, LTE, LTE-Advanced (LTE-A) , 3GPP 4G, 3GPP 5G NR, 3GPP Release 16 and onwards, a satellite communications network, a high altitude platform network, and so on. It is contemplated that along with the developments of network architectures and new service scenarios, all embodiments in the present disclosure are also applicable to similar technical problems; and moreover, the terminologies recited in the present disclosure may change, which should not affect the principle of the present disclosure.

Fig. 1 illustrates a schematic diagram of a wireless communication system, i.e., an unmanned aerial system (UAS) . In Fig. 1, the wireless communication system includes UAV UE 101, and three BSs 102 (including BS 102-A, BS 102-B, and BS-102-C, and hereinafter may be referred to as BS 102 for short) . BS 102-Amanages cell 111, BS 102-B manages cell 112, and BS 102-C manages cell 113. The UAV UE is moving. At time T1, the UAV UE is at the position marked by 101-T1, and accesses cell 112 with a physical cell ID (PCI) PCI #0; at time T2, the UAV UE is at the position marked by 101-T2 and accesses cell 111 with a physical cell ID PCI #1, and at time T3, the UAV UE is at the position marked by 101-T3 and accesses cell 113 with a physical cell ID PCI #2.

The UE 101 may include a UAV UE, unmanned vehicles, or other user equipment, and is referred to as UE for short in the present disclosure. The UE may communicate directly with the BS 102 via uplink (UL) communication signals.

The BSs 102 may be distributed over a geographic region. In certain embodiments, each of the BSs 102 may also be referred to as an access point, an access terminal, a base, a macro cell, a Node-B, an enhanced Node B (eNB) , a gNB, a Home Node-B, a relay node, or any device described using other terminology used in the art. The BSs 102 are generally parts of a radio access network that may include one or more controllers communicably coupled to one or more corresponding BSs 102.

The wireless communication system is compatible with any type of network that is capable of sending and receiving wireless communication signals. For example, the wireless communication system is compatible with a wireless communication network, a cellular telephone network, a time division multiple access (TDMA) -based network, a code division multiple access (CDMA) -based network, an orthogonal frequency division multiple access (OFDMA) -based network, an LTE network, a 3 ^rd generation partnership project (3GPP) -based network, a 3GPP 5G network, a satellite communications network, a high altitude platform network, and/or other communications networks.

In some embodiments, the wireless communication system is compatible with the 5G new radio (NR) of the 3GPP protocol, wherein the BSs 102 transmit data using an orthogonal frequency division multiplexing (OFDM) modulation scheme on the downlink and the UEs transmit data on the uplink using a discrete Fourier transform-spread-orthogonal frequency division multiplexing (DFT-S-OFDM) or a cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM) scheme. More generally, the wireless communication system may implement some other open or proprietary communication protocols, for example, WiMAX, among other protocols.

In some other embodiments, the BS 102 may communicate using other communication protocols, such as the IEEE 802.11 family of wireless communication protocols. Further, in some embodiments, the BS 102 may communicate over licensed spectrums, whereas in other embodiments the BS 102 may communicate over unlicensed spectrums. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol. In another embodiment, the BS 102 may communicate with the UEs using 3GPP 5G protocols.

Even though a specific number of UEs and BS is depicted in Fig. 1, persons skilled in the art will recognize that any number of UEs and BSs may be included in the wireless communication system.

In Fig. 1, the UAV UE may be ascending (when T1 is earlier than T3) or descending (when T1 is later than T3) , and the UAV UE may move in the vertical direction at a relative high speed. However, the cellular network may be optimized for terrestrial UEs, and the main beams of cells are usually down-tilted and may not have continuous coverage in the vertical direction. On the other hand, when the height of the UAV UE increases, the UAV UE may detect more and more cells and may quickly switch among beams from multiple neighbor cells. Specifically, there may be the following problems:

1. Because the beams or cell are frequently changed in a short period, there may be large RRC signaling overhead for measurement and handover during the ascending period or descending period, which may also cause larger UL interference.

2. The vertical coverage of sidelobe of cells may not be continuous, which may cause an RLF or HOF frequently during the ascending period or descending period.

3. Beams/cells are changed quickly in a short period; therefore, the measurement and handover procedure are performed in short period of time, which requires high UE capability.

In an RRC_CONNECTED state, the UE may measure multiple beams (at least one) of a cell and the measurements results (power values) are averaged to derive the cell quality. In doing so, the UE is configured to consider a subset of the detected beams. Filtering takes place at two different levels: at the physical layer to derive beam quality and then at the RRC level to derive cell quality from multiple beams. Cell quality from beam measurements is derived in the same way for the serving cell (s) and for the non-serving cell (s) . Measurement reports may contain the measurement results of the X best beams if the UE is configured to do so by the BS.

At the block marked by "Beam Consolidation/Selection, " the beam specific measurements are consolidated to derive cell quality. At the block marked by "Beam Selection for Beam Reporting, " a number of measurements may be selected from the measurements for beam reporting.

The present disclosure proposes some solutions for beam consolidation/selection and beam selection. Other parts of Fig. 2 may refer to 3GPP documents, for example, section 9.2.4 of TS 38.300, whereby such details are omitted here.

In the present disclosure, the BS may configure one or more conditions associated with the movement of the UAV UE. In the case that at least one condition is fulfilled, the UE may be considered as in vertical movement. The one or more conditions may include at least one of the following:

1. H1 event being triggered;

An H1 event suggests that the height of the UE becomes higher than a threshold. In the case that an H1 event is triggered, the UE may be determined as in vertical movement. In the case that an H1 event is not triggered, the UE may be determined as not in vertical movement.

2. H2 event being triggered;

An H2 event suggests that the height of the UE becomes lower than a threshold. In the case that an H2 event is triggered, the UE may be determined as not in vertical movement. In the case that an H2 event is not triggered, the UE may be determined as in vertical movement.

3. the height of the UE being higher than a first threshold configured by the BS;

The BS may configure a first height threshold, for example, the first threshold may be 10m (or other values) . In the case that the height of the UE becomes higher than the first height threshold, i.e., the height of the UE is higher than 10m, the UE may be determined as in vertical movement.

4. the height of the UE being lower than a second threshold configured by the BS;

The BS may configure a second height threshold, for example, the second height threshold may be 2m (or other values) . In the case that the height of the UE becomes lower than the second height threshold, i.e., the height of the UE is lower than 2m, the UE may be determined as not in vertical movement.

In some embodiments, the first height threshold and the second height threshold may have the same value.

5. a time duration in which the H1 event is triggered being longer than a first time threshold;

The BS may configure a first time threshold, for example, the configured first time threshold may be 5s (or other values) . In the case that H1 event is triggered for a time duration longer than the first time threshold, i.e., H1 event is triggered for a time duration longer than 5s, the UE may be determined as in vertical movement.

6. a time duration in which the H2 event is triggered being longer than a first time threshold;

The BS may configure a first time threshold, for example, the configured first time threshold may be 5s (or other values) . In the case that H2 event is triggered for a time duration longer than the first time threshold, i.e., H2 event is triggered for a time duration longer than 5s, the UE may be determined as not in vertical movement.

In some embodiments, the time threshold associated with the H1 event and that associated with the H2 event may be different, for example, the time threshold associated with the H1 event is 5s, and the time threshold associated with the H2 event is 2s.

7. a time duration in which the height of the UE is higher than the first configured height threshold being longer than a second time threshold;

The BS may configure a first hight threshold and a second time threshold, for example, the configured first hight threshold may be 10m (or other values) , and the configured second time threshold may be 5s (or other values) . In the case that the time duration in which the height of the UE is higher than 10m is longer than 5s, the UE may be determined as in vertical movement.

8. a time duration in which the height of the UE is lower than the second configured height threshold being longer than a third time threshold;

The BS may configure a second hight threshold and a third time threshold, for example, the configured second hight threshold may be 2m (or other values) , and the configured third time threshold may be 4s (or other values) . In the case that the time duration in which the height of the UE is lower than 2m is longer than 4s, the UE may be determined as not in vertical movement.

9. a vertical speed of the UE being higher than a vertical speed threshold;

The BS may configure a vertical speed threshold, for example, the vertical speed threshold may be 1m/s (or other values) . In the case that the vertical speed of the UE is higher than the vertical speed threshold, i.e., the vertical speed of the UE is higher than 1m/s, the UE may be determined as in vertical movement. Otherwise, the UE may be determined as not in vertical movement.

10. a vertical acceleration of the UE being higher than a vertical acceleration threshold;

The BS may configure a vertical acceleration threshold, for example, the vertical acceleration threshold may be 1m/s ² (or other values) . In the case that the vertical acceleration of the UE is higher than the vertical acceleration threshold, i.e., the vertical acceleration of the UE is higher than 1m/s ², the UE may be determined as in vertical movement. Otherwise, the UE may be determined as not in vertical movement.

11. an average vertical speed of the UE during a time duration being higher than an average vertical speed threshold during a time duration;

The BS may configure an average vertical speed threshold, for example, the average vertical speed threshold may be 1m/s (or other values) . In the case that the average vertical speed of the UE is higher than the average vertical speed threshold, i.e., the average vertical speed of the UE is higher than 1m/s, the UE may be determined as in vertical movement. Otherwise, the UE may be determined as not in vertical movement.

12. an average acceleration speed of the UE during a time duration being higher than an average vertical acceleration threshold during a time duration;

The BS may configure an average vertical acceleration threshold, for example, the average vertical acceleration threshold may be 1m/s ² (or other values) . In the case that the average vertical acceleration of the UE is higher than the average vertical acceleration threshold, i.e., the average vertical acceleration of the UE is higher than 1m/s ², the UE may be determined as in vertical movement. Otherwise, the UE may be determined as not in vertical movement.

13. a total number of changed beams or changed cells during a time duration being higher than a threshold associated with a total number of changed beams or changed cells during a time duration;

The BS may configure a maximum total number of changed beams or changed cells, and a time duration. For example, the maximum total number of changed beams or changed cells may be 5, and the time duration may be 10s. In the case that the total number of changed beams or changed cells during the time duration is more than the maximum total number of changed beams or changed cells, for example, the total number of changed beams or changed cells during 10s is more than 5, the UE may be determined as in vertical movement. Otherwise, the UE may be determined as not in vertical movement.

14. a height variation of the UE during a time duration being higher than a height variation threshold.

The BS may configure a height variation threshold, and a time duration. For example, the height variation threshold may be 5m, and the time duration may be 10s. In the case that the height variation during the time duration is more than the height variation threshold, for example, the height variation during 10s is more than 5m, the UE may be determined as in vertical movement. Otherwise, the UE may be determined as not in vertical movement.

The present disclosure introduces a dedicated measurement configuration for a UAV UE in vertical movement. Hereinafter, this dedicated measurement configuration for a UAV UE in vertical movement is referred to as "dedicated measurement configuration" for simplicity. For a UAV UE, when it is not in vertical movement, it may apply a measurement configuration. When the UAV UE is in vertical movement, it may apply the dedicated measurement configuration.

In some embodiments, when the UAV UE determines that it is in vertical movement, it may transmit an indication to the BS, which indicates that at least one of the above conditions (for determining whether the UAV UE is in vertical movement) is fulfilled.

At the BS side, after receiving the indication, the BS is aware that the UAV UE is in vertical movement, and may transmit an indication to the UAV UE, to indicate the UAV UE to apply the dedicated measurement configuration.

In some other embodiments, when the UAV UE determines that it is in vertical movement based on at least one condition for determining whether the UAV UE is in vertical movement being fulfilled, it may apply the dedicated measurement configuration autonomously.

The dedicated measurement configuration may include at least one of the following:

1. a consolidation threshold;

A new consolidation threshold may be configured for a UE in vertical movement compared with a UE not in vertical movement.

In particular, a higher consolidation threshold may be configured for a UE which is ascending. During beam consolidation/selection, a higher consolidation threshold may be applied, and the beams with not so good measurement result may not be consolidated to the cell results. Therefore, the cell result may be higher, and may fulfil the event condition quicker.

2. a maximum number of consolidation beams;

A new maximum number of consolidation beams may be configured. For example, the maximum number may be configured as two, and in this case, the beam associated with a highest cell measurement result and a beam associated with a second highest cell measurement result are consolidated.

3. a beam associated with a highest cell measurement result;

The beam with the highest measurement result may be used as the cell result. Therefore, the cell result may be the highest, and may fulfil the event condition quicker.

4. a trigger event threshold;

A specific trigger event threshold may be configured. For example, a lower threshold, or a smaller hysteresis value may be configured, thus event may be trigger quicker. For example, a lower hysteresis value may be configured,

5. a report amount;

A specific report amount may be configured for the UAV UE that is ascending. In this way, the amount of measurement reports is controlled.

6. a TTT configuration; or

A specific TTT configuration which can trigger report quicker may be configured. For example, the TTT may be configured with a smaller value, such that the report is triggered quicker.

7. a measurement object (MO) and report configuration.

A specific measurement object and report configuration may be configured for the UAV UE that is ascending.

In some embodiments, the above parameters in the dedicated measurement configuration may be configured with a new value. In some other embodiments, a scaling factor is introduced, and the parameters in the dedicated measurement configuration may be obtained by multiplying the existing configured parameter with the scaling factor. In some other embodiments, an offset is introduced, and the parameters in the dedicated measurement configuration may be obtained by applying the existing configured parameter with the offset. It should be noted that for different parameters, the applied scaling factor or offset may be the same, or may be different.

As shown in Fig. 3, when beam failure is detected by a UE, it may trigger BFR. In the case that the RACH procedure is successful, the BFR is considered as successful; in the case that the RACH procedure fails, the UAV UE may declare an RLF, and perform a re-establishment procedure.

For the UAV UE in a vertical movement (such as ascending or descending) , events such as BFD and RLF may need to be triggered quicker. Therefore, the present disclosure proposes a method for fast BFD and BFR skipping.

Specifically, a timer for fast BFD (e.g., beam failure detection timer) , or a counter threshold for fast BFD (e.g., beam failure instance max count) , or both, may be configured. Both the timer for fast BFD and the counter threshold for fast BFD may be configured with a value, such that the fast BFD may be triggered quicker.

When a UAV UE is in vertical movement, the BS may indicate the UAV UE to apply the fast BFD configuration, or the UAV UE may apply the fast BFD configuration autonomously. The UAV UE may evaluate the beam failure based on the timer for fast BFD and the counter threshold for fast BFD. For example, if a beam failure instance indication has been received from the lower layers, the UAV UE may start or restart the timer for fast BFD and increment counter of BFI (e.g., BFI_COUNTER) by 1. When the value of the BFI counter is larger than or equal to the counter threshold for fast BFD, a BFD may be triggered for the cell, or the lower layer may indicate beam failure to the upper layer.

In some other embodiments, the BFR may be skipped, i.e., skipping the RACH procedure, and directly declaring an RLF. In particular, when a UAV UE is in vertical movement, the BS may indicate the UAV UE to enable BFR skip, or the UAV UE may enable BFR skip autonomously.

For example, in a MAC layer, if the value of the BFI counter is larger than or equal to a threshold, for example, the counter threshold for fast BFD, the serving cell is SpCell, and BFR skip is enabled, and the MAC layer may indicate beam failure of SpCell to upper layers. In some other embodiments, whether BFR skip is enabled or not is determined by upper layers.

In the RRC layer, upon receiving an indication of beam failure of SpCell with BFR skip from the MAC layer, it may consider a radio link failure is detected, and may declare an RLF. In the case that the MAC layer does not indicate that BFR skip is enabled, the RRC may determine that the UAV UE is in vertical movement, and may further determine that BFR skip is enabled autonomously or based on an indication from the BS.

In some embodiments, a UAV UE may be moving, and may be configured with a fast BFR procedure, which may include beam failure detection and fast beam failure recovery. The UAV UE may continuously evaluate whether the conditions for determining whether the UAV UE is in vertical movement are fulfilled. In the case that the UAV UE is in vertical movement, it may be configured by the BS or autonomously apply the fast BFD or BFR configuration.

It should be noted that the parameters such as the timer for fast BFD or the counter threshold for fast BFD may be configured with a new value. In some other embodiments, a scaling factor is introduced, and the timer for fast BFD or the counter threshold for fast BFD may be obtained by multiplying the existing timer or counter threshold with the scaling factor. In some other embodiments, an offset is introduced, and the timer for fast BFD or the counter threshold for fast BFD may be obtained by applying the existing timer or the existing counter with the offset. It should be noted that for different parameters, the applied scaling factor or offset may be the same, or may be different.

As shown in Fig. 4, when an N310 out-of-sync indication is received, timer T310 is triggered, when timer T310 is running, an N311 in-sync indication is received and the radio link is recovered. When timer T310 expires, an RLF is declared.

Timer T312 may be configured and enabled per MO, when timer T310 is running, timer T312 is started. When timer T312 expires, an RLF is declared.

The present disclosure introduces a time for quick RLF, which may be configured for a UAV UE when the UAV UE is in vertical movement. The quick RLF may be configured by the BS by transmitting an indication to the UAV UE, or by the UAV UE autonomously when the UAV UE is in vertical movement.

The timer for quick RLF may be started when an N310 out-of-sync indication is received, or when timer T310 is running. In the case that the timer for quick RLF expires, an RLF may be declared. The timer for quick RLF may be configured with a value shorter than that of timer T310.

When the timer for quick RLF is running, an N311 in-sync indication is received, and physical layer problem is recovered, the timer for quick RLF may be stopped.

It should be noted that the value of the timer for quick RLF may be configured with a new value. In some other embodiments, a scaling factor is introduced, and the timer for quick RLF may be obtained by multiplying the existing timer with the scaling factor. In some other embodiments, an offset is introduced, and the timer for quick RLF may be obtained by applying the existing timer with the offset.

In operating 501, the UE may determine whether one or more conditions associated with movement of the UE are fulfilled. In operation 502, the UE may perform at least one of the following in the case that at least one of the one or more conditions is fulfilled: transmit a first indication indicating that at least one of the one or more conditions is fulfilled; adjust a measurement configuration; apply a fast BFD configuration; skip a BFR procedure; or enable an RLF procedure. For example, the UE may adjust the measurement configuration to the dedicated measurement configuration.

In operation 502, the UE may autonomously perform at least one of the following: adjust the measurement configuration; apply the fast BFD configuration; skip the BFR procedure; or enable the quick RLF procedure.

In operation 601, the BS may receive, from a UE, a first indication indicating that at least one of the one or more conditions is fulfilled; and in operation 602, the BS may transmit, to the UE, a second indication indicating the UE to perform at least one of the following: adjust a measurement configuration; apply a fast BFD configuration; skip a BFR procedure; or enable a quick RLF procedure.

Correspondingly, at the UE side, the UE may be further configured to: receive a second indication indicating the UE to perform at least one of the following: adjust the measurement configuration; apply the fast BFD configuration; skip the BFR procedure; or enable the quick RLF procedure. That is, the UE may perform these operations based on indication from the BS.

In some embodiments, in the case that a total number of a beam failure indication exceeds a maximum threshold for beam failure indication and BFR skip is enabled, the UE is further configured to: skip the BFR procedure and declare an RLF.

In some embodiments, the UE may start a timer for the quick RLF procedure in the case that timer T310 is running or an N310 out-of-synchronization indication is received. In some embodiments, the UE may declare an RLF when the timer for the quick RLF procedure expires.

As shown in Fig. 7, an example of the apparatus 700 may include at least one processor 704 and at least one transceiver 702 coupled to the processor 704. The apparatus 700 may be a UE, a BS, a RAN node, a source node, a target node, a third node, or any other device with similar functions.

Although in this figure, elements such as the at least one transceiver 702 and processor 704 are described in the singular, the plural is contemplated unless a limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the transceiver 702 may be divided into two devices, such as a receiving circuitry and a transmitting circuitry. In some embodiments of the present disclosure, the apparatus 700 may further include an input device, a memory, and/or other components.

In some embodiments of the present disclosure, the apparatus 700 may be a UE. The transceiver 702 and the processor 704 may interact with each other so as to perform the operations of the UE described in any of Figs. 1-6. The transceiver 702 and the processor 704 may interact with each other so as to perform the operations of the BS described in any of Figs. 1-6.

In some embodiments of the present disclosure, the apparatus 700 may further include at least one non-transitory computer-readable medium.

For example, in some embodiments of the present disclosure, the non-transitory computer-readable medium may have stored thereon computer-executable instructions to cause the processor 704 to implement the method with respect to the UE as described above. For example, the computer-executable instructions, when executed, cause the processor 704 interacting with transceiver 702 to perform the operations of the UE described in any of Figs. 1-6.

The method of the present disclosure can be implemented on a programmed processor. However, controllers, flowcharts, and modules may also be implemented on a general purpose or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an integrated circuit, a hardware electronic or logic circuit such as a discrete element circuit, a programmable logic device, or the like. In general, any device that has a finite state machine capable of implementing the flowcharts shown in the figures may be used to implement the processing functions of the present disclosure.

While the present disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in other embodiments. Also, all of the elements shown in each figure are not necessary for operation of the disclosed embodiments. For example, one skilled in the art of the disclosed embodiments would be capable of making and using the teachings of the present disclosure by simply employing the elements of the independent claims. Accordingly, the embodiments of the present disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the present disclosure.

In this disclosure, relational terms such as "first, " "second, " and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises, " "comprising, " or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "a, " "an, " or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. Also, the term "another" is defined as at least a second or more. The terms "including, " "having, " and the like, as used herein, are defined as "comprising. "

Claims

A user equipment (UE) , comprising:

a transceiver; and

a processor coupled with the transceiver and configured to:

determine whether one or more conditions associated with movement of the UE are fulfilled; and

perform at least one of the following in the case that at least one of the one or more conditions is fulfilled:

transmit a first indication indicating that at least one of the one or more conditions is fulfilled;

adjust a measurement configuration;

apply a fast beam failure detection (BFD) configuration;

skip a beam failure recovery (BFR) procedure; or

enable a quick radio link failure (RLF) procedure.
The UE of Claim 1, wherein the processor is further configured to:

receive a second indication indicating the UE to perform at least one of the following:

adjust the measurement configuration;

apply the fast BFD configuration;

skip the BFR procedure; or

enable the quick RLF procedure.
The UE of Claim 1, wherein the one or more conditions associated with movement of the UE include at least one of the following:

a measurement event associated with a height of the UE being triggered;

a height of the UE being higher than a first configured height threshold;

a height of the UE being lower than a second configured height threshold;

a time duration in which the event associated with a height of the UE is triggered being longer than a first time threshold;

a time duration in which the height of the UE is higher than the first configured height threshold being longer than a second time threshold;

a time duration in which the height of the UE is lower than the second configured height threshold being longer than a third time threshold;

a vertical speed of the UE being higher than a vertical speed threshold;

a vertical acceleration of the UE being higher than a vertical acceleration threshold;

an average vertical speed of the UE during a time duration being higher than an average vertical speed threshold during a time duration;

an average acceleration speed of the UE during a time duration being higher than an average vertical acceleration threshold during a time duration;

a total number of changed beams or changed cells during a time duration being higher than a threshold associated with a total number of changed beams or changed cells during a time duration; or

a height variation of the UE during a time duration being higher than a height variation threshold.
The UE of Claim 1, wherein the measurement configuration is associated with at least one of the following:

a consolidation threshold;

a maximum number of consolidation beams;

a beam associated with a highest cell measurement result;

a trigger event threshold;

a report amount;

a time to trigger (TTT) configuration; or

a measurement object and report configuration.
The UE of Claim 1, wherein the fast BFD configuration includes a timer for beam failure detection and a maximum number for beam failure instances.
The UE of Claim 1, wherein in the case that a total number of a beam failure indication exceeds a maximum threshold for beam failure indication and BFR skip is enabled, the processor is further configured to:

skip the BFR procedure and declare an RLF.

Claims for BFR skip
The UE of Claim 1, wherein the processor is further configured to:

start a timer for the quick RLF procedure in the case that timer T310 is running or an N310 out-of-synchronization indication is received.
The UE of Claim 6, wherein the processor is further configured to:

declare an RLF when the timer for the quick RLF procedure expires.
A base station (BS) , comprising:

a transceiver; and

a processor coupled with the transceiver and configured to:

receive, from a user equipment (UE) , a first indication indicating that at least one of the one or more conditions is fulfilled; and

transmit, to the UE, a second indication indicating the UE to perform at least one of the following:

adjust a measurement configuration;

apply a fast beam failure detection (BFD) configuration;

skip a beam failure recovery (BFR) procedure; or

enable a quick radio link failure (RLF) procedure.
A method performed by a user equipment (UE) , comprising:

determining whether one or more conditions associated with movement of the UE are fulfilled; and

performing at least one of the following in the case that at least one of the one or more conditions is fulfilled:

transmitting a first indication indicating that at least one of the one or more conditions is fulfilled;

adjusting a measurement configuration;

applying a fast beam failure detection (BFD) configuration;

skipping a beam failure recovery (BFR) procedure; or

enabling a quick radio link failure (RLF) procedure.
The method of Claim 10, further comprising:

receiving a second indication indicating the UE to perform at least one of the following:

adjusting the measurement configuration;

applying the fast BFD configuration;

skipping the BFR procedure; or

enabling the quick RLF procedure.
The method of Claim 10, wherein the one or more conditions associated with movement of the UE include at least one of the following:

a measurement event associated with a height of the UE being triggered;

a height of the UE being higher than a first configured height threshold;

a height of the UE being lower than a second configured height threshold;

a time duration in which the event associated with a height of the UE is triggered being longer than a first time threshold;

a time duration in which the height of the UE is higher than the first configured height threshold being longer than a second time threshold;

a time duration in which the height of the UE is lower than the second configured height threshold being longer than a third time threshold;

a vertical speed of the UE being higher than a vertical speed threshold;

a vertical acceleration of the UE being higher than a vertical acceleration threshold;

an average vertical speed of the UE during a time duration being higher than an average vertical speed threshold during a time duration;

an average acceleration speed of the UE during a time duration being higher than an average vertical acceleration threshold during a time duration;

a total number of changed beams or changed cells during a time duration being higher than a threshold associated with a total number of changed beams or changed cells during a time duration; or

a height variation of the UE during a time duration being higher than a height variation threshold.
The method of Claim 10, wherein the measurement configuration is associated with at least one of the following:

a consolidation threshold;

a maximum number of consolidation beams;

a beam associated with a highest cell measurement result;

a trigger event threshold;

a report amount;

a time to trigger (TTT) configuration; or

a measurement object and report configuration.
The method of Claim 10, wherein the fast BFD configuration includes a timer for beam failure detection and a maximum number for beam failure instances.
The method of Claim 10, wherein in the case that a total number of a beam failure indication exceeds a maximum threshold for beam failure indication and BFR skip is enabled, the processor is further configured to:

skip the BFR procedure and declare an RLF.