WO2023065121A1

WO2023065121A1 - Methods and apparatuses for triggering successful handover report

Info

Publication number: WO2023065121A1
Application number: PCT/CN2021/124760
Authority: WO
Inventors: Lianhai WU; Le Yan; Mingzeng Dai; Yibin ZHUO; Congchi ZHANG
Original assignee: Lenovo (Beijing) Limited
Priority date: 2021-10-19
Filing date: 2021-10-19
Publication date: 2023-04-27

Abstract

Disclosed are methods and apparatuses for logging and transmitting at least one Successful Handover Report (SHR) under at least one trigger condition for SHR. An embodiment of the subject application provides an apparatus. The apparatus includes: a processor; and a wireless transceiver coupled to the processor, wherein the processor is configured to: receive, with the wireless transceiver, at least one trigger condition for successful handover report (SHR) from a source base station (BS) via a radio resource control (RRC) reconfiguration message; perform handover (HO) upon reception of a HO command or upon a conditional handover (CHO) condition being met; determine whether the at least one trigger condition is met during HO; and log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO. In some embodiments, the UE may transmit the at least one SHR triggered by at least one condition to the target BS after successful handover.

Description

METHODS AND APPARATUSES FOR TRIGGERING SUCCESSFUL HANDOVER REPORT

TECHNICAL FIELD

The present disclosure generally relates to wireless communication technologies, and especially relates to methods and apparatuses for logging and transmitting at least one Successful Handover Report (SHR) under at least one trigger condition for SHR.

BACKGROUND OF THE INVENTION

The Mobility Robustness Optimization (MRO) function in New Radio (NR) could be enhanced to provide a more robust mobility via reporting failure events observed during successful handovers. A solution to this problem is to configure a User Equipment (UE) to compile a report associated to a successful handover comprising a set of measurements collected during the handover phase, i.e. measurement at the handover trigger, measurement at the end of handover execution or measurement after handover execution. The UE could be configured with triggering conditions to compile the SHR; hence the report would be triggered only if the conditions are met.

The availability of a SHR may be indicated by the Handover Complete message (e.g., RRCReconfigurationComplete) transmitted from a UE to target Next Generation (NG) Radio Access Network (RAN) node over RRC. The target NG-RAN node may fetch information of an SHR via UE Information Request/Response mechanism. In addition, the target NG-RAN node could then forward the SHR to the source NG-RAN node to indicate failures experienced during a successful handover event.

Upon reception of an SHR, the receiving node is able to analyze whether its mobility configuration needs adjustment. Such adjustments may result in changes of mobility configurations, such as changes of Radio Link Management (RLM) configurations or changes of mobility thresholds between the source node and the target node. In addition, the target NG-RAN node, in the performed handover, may further optimize the dedicated Random Access Channel (RACH) beam resources based on the beam measurements reported upon successful handovers.

SUMMARY

Various embodiments and methods of the present disclosure provide solutions related to triggering SHR with multiple conditions.

According to some embodiments of the present disclosure, an exemplary method performed by a UE (User equipment) is provided. The method includes: receiving at least one trigger condition for SHR from a source base station (BS) via an RRC reconfiguration message; performing handover (HO) upon reception of a HO command or upon a conditional handover (CHO) condition being met; determining whether the at least one trigger condition is met during HO; and logging the parameters for at least one SHR in response to that the at least one trigger condition is met during HO.

In some embodiments, the method further includes transmitting an indicator indicating availability of the at least one SHR after accessing to the target BS.

In some embodiments, the method further comprises: receiving a UE information request from the target BS; and transmitting UE information response including at least one SHR to the target BS.

In some embodiments, the at least one trigger condition comprises at least one of: a first threshold of a physical layer problem timer, a second threshold for a timer for initiating failure recovery based on triggering a measurement report, or a third threshold for a handover timer, and wherein the UE is triggered to log parameters for SHR in response to at least one of the followings: an elapsed time value of the physical layer problem timer being greater than the first threshold multiplied with a first configured value for the physical layer problem timer; an elapsed time value of the timer for initiating failure recovery based on triggering a measurement report being greater than the second threshold multiplied with a second configured value for the timer for initiating failure recovery based on triggering a measurement report; or an elapsed time value of the handover timer being greater than the third threshold multiplied with a third configured value for the handover timer.

In some embodiments, the first threshold and the second threshold are configured by a source BS, and the third threshold is configured by the source BS or the target BS.

In some embodiments, wherein receiving the at least one trigger condition comprises receiving only one trigger condition, and logging the parameters for the at least one SHR in response to that the at least one trigger condition is met during HO comprises logging the parameters for a SHR in response to the one trigger condition being met.

In some embodiments, wherein receiving the at least one trigger condition comprises receiving more than one trigger conditions.

In some embodiments, logging the parameters for at least one SHR in response to that the at least one trigger condition is met during HO further comprises: logging parameters for the SHR associated with a latest met trigger condition of the more than one trigger conditions; and transmitting a SHR including the parameters to target BS.

In some embodiments, logging the parameters for at least one SHR in response to that the at least one trigger condition is met during HO further comprises: logging the parameters for a first SHR associated with a first met trigger condition of the more than one trigger conditions; discarding the first SHR and logging the parameters for a second SHR associated with a second met trigger condition of the more than one trigger conditions; and transmitting a second SHR to the target BS.

In some embodiments, logging the parameters for at least one SHR in response to that the at least one trigger condition is met during HO further comprises: logging parameters for SHR associated with a first met trigger condition of the more than one trigger conditions without further checking whether at least one other trigger condition of the more than one trigger conditions is met later; and transmitting a SHR including the parameters.

In some embodiments, logging the parameters for at least one SHR in response to that the at least one trigger condition is met during HO further comprises: logging parameter associated with a first met trigger condition of the more than one trigger conditions without logging parameters associated with at least one other trigger condition of the more than one trigger conditions which is even met later; and transmitting a SHR including the parameters.

In some embodiments, logging the parameters for at least one SHR in response to that the at least one trigger condition is met during HO further comprises: logging a first set of parameters associated with a first met trigger condition of the more than one trigger conditions; logging a second set of parameters associated with a second met trigger condition; and transmitting one single SHR including the first set parameters and the second set parameters.

In some embodiments, logging the parameters for at least one SHR in response to that the at least one trigger condition is met during HO further comprises: logging a first set of parameters associated with a first met trigger condition of the more than one trigger conditions; logging a second set of parameters associated with a second met trigger condition of the more than one trigger conditions; and transmitting separate SHRs including the first set of parameters and the second set of parameters respectively.

According to some embodiments of the present disclosure, an exemplary method performed by a target BS is provided. The method includes: transmitting an HO request acknowledge to a source BS; receiving an indicator indicating availability of at least one SHR from a UE, wherein the at least one SHR including at least one set parameters associated with at least one trigger condition that is met during HO.

In some embodiments, the at least one trigger condition comprises at least one of: a first threshold of a physical layer problem timer, a second threshold for a timer for initiating failure recovery based on triggering a measurement report, or a third threshold for a handover timer.

In some embodiments, the method further comprises: transmitting an indicator to the source BS indicating whether the third threshold is configured by the target BS.

In some embodiments, the method further comprises: transmitting the third threshold via the HO request acknowledge to the source BS, wherein the indicator indicates that the third threshold is configured by the target BS.

In some embodiments, the method further comprises: transmitting a UE information request to the UE; and receiving the at least one SHR from the UE.

In some embodiments, the method further comprises: transferring the received at least one SHR to the source BS.

In some embodiments, the method further comprises: removing parameters associated with the third threshold from the at least one received SHR before transferring the received at least one SHR, in response to: the third threshold is configured by the target BS; an elapsed time value of the handover timer being greater than the third threshold multiplied with a configured value for the handover timer at the UE; and the parameters associated with the third threshold are logged in the at least one SHR.

According to some embodiments of the present disclosure, an exemplary method performed by a target BS is provided. The method includes: receiving an HO request acknowledge from a target BS; transmitting at least one trigger condition for SHR via an RRC reconfiguration message to a UE; and transmitting an HO command or a CHO configuration to the UE.

In some embodiments, the method further comprises: receiving an indicator from the target BS indicating whether the third threshold for the HO timer is configured by the target BS; and receiving the third threshold for the HO timer via the HO request acknowledge in response to that the indicator indicating the third threshold is configured by the target BS.

In some embodiments, the method further comprises receiving at least one SHR from the target BS including at least one set of parameters associated with at least one trigger condition that is met during a HO.

According to some embodiments of the present disclosure, an exemplary UE is provided. The UE includes: a processor; and a wireless transceiver coupled to the processor, wherein the processor is configured to: receive, with the wireless transceiver, at least one trigger condition for SHR from a source BS via an RRC reconfiguration message; perform HO upon reception of a HO command or upon a CHO condition being met; determine whether the at least one trigger condition is met during HO; and log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO.

In some embodiments, the processor is further configured to transmit, with the wireless transceiver, an indicator indicating availability of the at least one SHR after accessing to the target BS.

In some embodiments, the processor is further configured to: receive, with the wireless transceiver, a UE information request from the target BS; and transmit, with the wireless transceiver, UE information response including at least one SHR to the target BS.

In some embodiments, the at least one trigger condition comprises at least one of: a first threshold of a physical layer problem timer, a second threshold for a timer for initiating failure recovery based on triggering a measurement report, or a third threshold for a handover timer, and wherein the processor is configured to log parameters for SHR in response to at least one of the followings: an elapsed time value of the physical layer problem timer being greater than the first threshold multiplied with a first configured value for the physical layer problem timer; an elapsed time value of the timer for initiating failure recovery based on triggering a measurement report being greater than the second threshold multiplied with a second configured value for the timer for initiating failure recovery based on triggering a measurement report; or an elapsed time value of the handover timer being greater than the third threshold multiplied with a third configured value for the handover timer.

In some embodiment, to receive the at least one trigger condition, the processor is further configured to receive only one trigger condition, and to log the parameters for the at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to log the parameters for a SHR in response to the one trigger condition being met.

In some embodiments, to receive the at least one trigger condition, the processor is further configured to receive more than one trigger conditions.

In some embodiments, to log the parameters for the at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to: log parameters for the SHR associated with a latest met trigger condition of the more than one trigger conditions; and transmit, with the wireless transceiver, a SHR including the parameters to target BS.

In some embodiments, to log the parameters for the at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to: log the parameters for a first SHR associated with a first met trigger condition of the more than one trigger conditions; discard the first SHR and logging the parameters for a second SHR associated with a second met trigger condition of the more than one trigger conditions; and transmit, with the wireless transceiver, a second SHR to the target BS.

In some embodiments, to log the parameters for the at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to: log parameters for SHR associated with a first met trigger condition of the more than one trigger conditions without further checking whether at least one other trigger condition of the more than one trigger conditions is met later; and transmit, with the wireless transceiver, a SHR including the parameters.

In some embodiments, to log the parameters for the at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to: log parameter associated with a first met trigger condition of the more than one trigger conditions without logging parameters associated with at least one other trigger condition of the more than one trigger conditions which is even met later; and transmit, with the wireless transceiver, a SHR including the parameters.

In some embodiments, to log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to: log a first set of parameters associated with a first met trigger condition of the more than one trigger conditions; log a second set of parameters associated with a second met trigger condition; and transmit, with the wireless transceiver, one single SHR including the first set parameters and the second set parameters.

In some embodiments, to log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to: log a first set of parameters associated with a first met trigger condition of the more than one trigger conditions; log a second set of parameters associated with a second met trigger condition of the more than one trigger conditions; and transmit, with the wireless transceiver, separate SHRs including the first set of parameters and the second set of parameters respectively.

According to some embodiments of the present disclosure, an exemplary target BS is provided. The target BS includes: a processor; and a wireless transceiver coupled to the processor, wherein the processor is configured to: transmit, with the wireless transceiver, a HO request acknowledge to a source BS; receive, with the wireless transceiver, an indicator indicating availability of at least one SHR from a UE, wherein the at least one SHR including at least one set parameters associated with at least one trigger condition that is met during HO.

In some embodiments, the processor is further configured to transmit, with the wireless transceiver, an indicator to the source BS indicating whether the third threshold is configured by the target BS.

In some embodiments, the processor is further configured to transmit, with the wireless transceiver, the third threshold via the HO request acknowledge to the source BS, wherein the indicator indicates that the third threshold is configured by the target BS.

In some embodiments, the processor is further configured to: transmit, with the wireless transceiver, a UE information request to the UE; and receive, with the wireless transceiver, the at least one SHR from the UE.

In some embodiments, the processor is further configured to transfer, with the wireless transceiver, the received at least one SHR to the source BS.

In some embodiments, the processor is further configured to: remove parameters associated with the third threshold from the at least one received SHR before transferring the received at least one SHR, in response to: the third threshold is configured by the target BS; an elapsed time value of the handover timer being greater than the third threshold multiplied with a configured value for the handover timer at the UE; and the set of parameters associated with the third threshold are logged in the at least one SHR.

According to some embodiments of the present disclosure, an exemplary source BS is provided. The source BS includes: a processor; and a wireless transceiver coupled to the processor, wherein the processor is configured to: receive, with the wireless transceiver, an HO request acknowledge from a target BS; transmit, with the wireless transceiver, at least one trigger condition for SHR via an RRC reconfiguration message to a UE; and transmit, with the wireless transceiver, an HO command or a CHO configuration to the UE.

In some embodiments, the processor is further configured to: receive, with the wireless transceiver, an indicator from the target BS indicating whether the third threshold for the HO timer is configured by the target BS; and receive, with the wireless transceiver, the third threshold for the HO timer via the HO request acknowledge in response to that the indicator indicating the third threshold is configured by the target BS.

In some embodiments, the processor is further configured to receive, with the wireless transceiver, at least one SHR from the target BS including at least one set of parameters associated with at least one trigger condition that is met during a HO.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which advantages and features of the present disclosure can be obtained, a description of the present disclosure is rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. These drawings depict only exemplary embodiments of the present disclosure and are not therefore intended to limit the scope of the present disclosure.

Figure 1 illustrates an exemplary flowchart of a method performed by a UE according to some embodiments of the present disclosure;

Figure 2 illustrates an exemplary signaling flowchart according to some embodiments of the present disclosure;

Figure 3 illustrates an exemplary flowchart of a method performed by a UE according to some embodiments of the present disclosure;

Figure 4 illustrates an exemplary flowchart of a method performed by a UE according to some embodiments of the present disclosure;

Figure 5 illustrates an exemplary flowchart of a method performed by a UE according to some embodiments of the present disclosure;

Figure 6 illustrates an exemplary flowchart of a method performed by a UE according to some embodiments of the present disclosure;

Figure 7 illustrates an exemplary flowchart of a method performed by a UE according to some embodiments of the present disclosure;

Figure 8 illustrates an exemplary flowchart of a method performed by a target BS according to some embodiments of the present disclosure;

Figure 9 illustrates an exemplary flowchart of a method performed by a source BS according to some embodiments of the present disclosure;

Figure 10 illustrates a simplified block diagram of an exemplary UE according to some other embodiments of the present disclosure;

Figure 11 illustrates a simplified block diagram of an exemplary target BS according to some other embodiments of the present disclosure; and

Figure 12 illustrates a simplified block diagram of an exemplary source BS according to some other 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 shown or in sequential order, or that among all illustrated operations 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 3GPP 5G NR, 3GPP long-term evolution (LTE) , 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.

In some embodiments of the present disclosure, UEs may include computing devices, such as desktop computers, laptop computers, personal digital assistants (PDAs) , tablet computers, smart televisions (e.g., televisions connected to the Internet) , set-top boxes, game consoles, security systems (including security cameras) , vehicle on-board computers, network devices (e.g., routers, switches, and modems) , road side units (RSUs) , or the like. According to an embodiment of the present disclosure, the UE may include a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiver, or any other device that is capable of sending and receiving communication signals on a wireless network. In some embodiments, the UE may include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the UE may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art.

In some embodiments of the present disclosure, a BS may be referred to as an access point, an access terminal, a base, a base unit, a macro cell, a wireless node, a Node-B, an enhanced Node-B, an evolved Node B (eNB) , a next generation Node B (gNB) , a Home Node-B, a relay node, or a device, or described using other terminology used in the art. The BS is generally part of a radio access network that may include a controller communicably coupled to the BS.

The present disclosure provides various methods and embodiment about logging at least one set of parameters associated with at least one met trigger condition in at least one SHR. An SHR may contain multiple parameters or measurements that could be used for MRO.

Figure 1 illustrates an exemplary flowchart of method 100 performed by a UE according to some embodiments of the present disclosure. It would be appreciated that in method 100 or in other methods described later, the UE is not a special UE; it can be a generic device or an apparatus, or a part of a device or an apparatus that uses the technical solution of the present application.

In operation 110, the UE receives at least one trigger condition for SHR from a source BS via an RRC reconfiguration message. The RRC reconfiguration message received by the UE includes at least one trigger condition.

In operation 120, the UE performs HO upon reception of an HO command or upon a CHO condition being met; the HO is a normal HO or a CHO.

In operation 130, the UE determines whether the at least one trigger condition is met during HO.

In operation 140, the UE logs parameters (or measurements) for at least one SHR in response to that the at least one trigger condition is met during the HO.

In some embodiments, after the UE logs parameters for the at least one SHR, the UE may transmit the at least one SHR including the parameters to the target BS.

In some embodiments, the UE may transmit an indicator to the target BS after the UE accesses to the target BS; the indicator indicates availability of the at least one SHR. In some embodiments, the indicator also indicate which trigger condition (s) are met. In some embodiment, the indicator may be transmitted in a HO complete message (e.g., RRCReconfigurationComplete) over RRC. In some embodiment, if the target BS needs the at least one SHR, it may send a UE information request message (e.g., UEInformationRequest) to the UE; upon reception of the UE information request message, the UE may transmit the at least one SHR to the target BS via a UE information response message (e.g., UEInformationResponse) .

In some embodiments, the UE may discard the at least one SHR (i.e., release the at least one SHR) after a certain period (e.g., 48 hours) since the at least one SHR is stored, even if the at least one SHR is not transmitted to the target BS.

In addition, in some embodiments, the target BS may forward the received at least one SHR to the source BS. The network may optimize its mobility and robustness at least based on the at least one SHR.

According to the present disclosure, the at least one trigger condition may trigger the UE to log parameters and/or measurements during HO if the at least one trigger condition is met; these parameters and/or measurements may be included in the at least one SHR, and they are useful for example, for MRO function of the network. These radio related parameters or measurements may be, for example, at least one of:

● the source cell and target cell related identifiers and measurements;

● the following radio related measurements:

◆ latest radio measurement results of the candidate target cells in the case of CHO;

◆ flag to indicate Radio Link Failure (RLF) issues in source cell during Dual Active Protocol Stack (DAPS) HO;

● the following time-related measurements:

◆ time elapsed between the CHO execution towards the target cell and the corresponding latest CHO configuration received for the selected target cell;

● location information.

In some embodiments, the at least one trigger condition comprises at least one of:

● a first threshold of a physical layer problem timer (e.g., timer T310 specified in 3GPP standard documents) ;

● a second threshold for a timer for initiating failure recovery based on triggering a measurement report (e.g., timer T312 specified in 3GPP standard documents) , or

● a third threshold for a handover timer (e.g., timer T304 specified in 3GPP standard documents)

In some embodiments, in operation 140, the UE is triggered to log parameters and/or measurements obtained during the HO in response to at least one of the followings:

● an elapsed time value of the physical layer problem timer being greater than the first threshold multiplied with a first configured value for the physical layer problem timer;

● an elapsed time value of the timer for initiating failure recovery based on triggering a measurement report being greater than the second threshold multiplied with a second configured value for the timer for initiating failure recovery based on triggering a measurement report; or

● an elapsed time value of the handover timer being greater than the third threshold multiplied with a third configured value for the handover timer.

Herein, the first configured value is the duration of the physical layer problem timer (e.g., T310) ; the second configured value is the duration of the timer for initiating failure recovery based on triggering a measurement report (e.g., T320) ; and the third configured value is the duration of the handover timer (e.g., T304) . If an elapsed time value of an aforementioned timer equals a configured value for the timer, the timer expires. If an aforementioned timer expires, the handover is failed.

The following Table 1 shows introductions of T304, T310, and T312 as specified in 3GPP standard documents, including a starting condition, a stop condition, an operation at expiry, and a possible general name for each of these timers.

Table 1

However, even if these three timers do not expire and the handover is successful, it does not mean that there is no any risk for HO, or it does not mean that the network does not need to be optimized. The greater the elapsed time value of the aforementioned timer, the bigger the risk for HO.

Therefore, the present disclosure introduces the first threshold, the second threshold, and the third threshold for evaluating the risk, the UE may logs parameters if at least one threshold is met.

In some embodiments, the first threshold may be 40%, 60%, or 80%.

In some embodiments, the second threshold may be 20%, 40%, 60%, or 80%.

In some embodiments, the third threshold may be 40%, 60%, or 80%.

For example, the first threshold for the physical layer problem timer is 60%, the first configured value for the physical layer problem timer is 500ms; if the elapsed time of the physical layer problem timer is greater than 300ms, the UE may be triggered to log parameters for SHR.

In some embodiments, the first threshold and the second threshold are configured by a source BS.

In some embodiments, the third threshold is configured by a source BS or a target BS; if the third threshold is configured by the target BS, the target BS may transmit the third threshold to the source BS, and the source BS may forward the third threshold to the UE. Therefore, no matter whether the third threshold is configured by the source BS or the target BS, the UE receives the third threshold form the source BS.

Figure 2 illustrates an exemplary signaling flowchart 200 for a third threshold configuration during a normal handover procedure according to some embodiments of the present disclosure.

As illustrated in Figure 2, a source BS make a normal handover decision, then it transmits handover request message 210 to a target BS. If certain handover conditions are met, the BS acknowledges the handover request, it may transmit handover request acknowledge message 250 to the source BS, wherein handover request acknowledge message 250 may include indicator 220 indicating whether a third threshold is configured by the target BS. If the BS decide to configure the third threshold, indicator 220 will indicate that the third threshold is configured by the target BS, and third threshold 230 may be included in a handover command included in handover request acknowledge message 250. After receiving handover request acknowledge message 250, the source BS may initial the handover procedure, the source BS may transmit RRC reconfiguration message 240 to the UE, wherein RRC reconfiguration message 240 may include the third threshold. If indicator 220 indicates that the target BS does not configure the third threshold, handover request acknowledge 250 does not contain the third threshold, but RRC Reconfiguration message 240 may still contain the third threshold, if the source BS configures the third threshold.

In some embodiments, RRC reconfiguration message 240 may also include a first threshold and/or a second threshold.

It would be appreciated that, for simplicity and concise, Figure 2 only illustrates some necessary signaling closely associated with the present disclosure. There may be other signaling not shown in Figure 2.

The example illustrated in Figure 2 is for a normal handover procedure. It would be appreciated that, according to the present disclosure, the CHO has a similar signaling flow for third threshold configuration.

According to the present disclosure, if an elapsed time value of the handover timer being greater than the third threshold multiplied with a third configured value for the handover timer, the UE will be triggered to log parameters for SHR associated with the third threshold; i.e., the UE will triggered to log parameters for SHR upon the third threshold is met during HO. The UE transmits an indicator indicating availability of the at least one SHR and/or and which trigger condition (s) are met after access to the target BS, and transmits the at least one SHR to the target BS after reception of a UE information request from the target BS, wherein the at least one SHR is included in a UE information response. After reception of the at least one SHR, the target BS may forward the at least one SHR to the source BS; however, if the third threshold is configured by the target BS, the parameters included in the at least one SHR which is associated with the third threshold will be removed before the target transmits the at least one SHR to the source BS, and not be forwarded to the source BS.

Figure 3 illustrates an exemplary flowchart of method 300 based on method 100 according to some embodiments of the present disclosure.

In operation 310, the UE receives only one trigger condition for SHR from a source BS via an RRC reconfiguration message. The trigger condition may be one of the first threshold, the second threshold, or the third threshold.

In some embodiments, if the target BS configures the third threshold and notifies the source BS by an indicator, e.g. indicator 220, the source BS will not configure any one of the first threshold, the second threshold, or the third threshold; and the source BS forwards the third threshold received from the target BS to the UE.

In operation 320, the UE performs HO upon reception of an HO command or upon a CHO condition being met.

In operation 330, the UE determines whether the received trigger condition is met during HO.

In operation 340, the UE logs parameters for a SHR in response to that the received trigger condition is met.

In some embodiments, after the UE accesses to the target BS, the UE may transmit the SHR to the target BS; or the UE may transmit an indicator indicating the availability of the SHR and/or the met trigger condition, and transmit the SHR in response to reception of an UE information request from the target BS.

If the trigger condition is the first threshold. or the second threshold, or the third threshold configured by the source BS, the target BS may forward the received SHR to the source BS; if the trigger condition is the third threshold, and the third threshold is configured by the target BS, the target BS will not forward the received SHR to the source BS.

For example, in operation 310, the UE receives an RRC reconfiguration message (e.g., RRCReconfiguration) including only the third threshold for the handover timer (e.g., T304) .

In this example, the third configured value for the handover timer is 1000ms, and the third threshold is 60%; i.e., the third threshold multiplied with the third configured value for the handover timer is 600ms.

In operation 320, the UE starts the handover timer and performs HO. In operation 330, during the HO, the UE determines that the elapsed time value of the handover timer is greater than 600ms; then in operation 340, the UE is triggered to log parameters for the SHR upon the elapsed time value of the handover timer being greater than 600ms, herein the logged parameters are called to be associated with the met trigger condition (in this example, the met trigger condition is the third threshold) .

In this example, the UE does not receive the first threshold and the second threshold; therefore, even if the physical layer problem timer (e.g., T310) and/or the timer for initiating failure recovery based on triggering a measurement report (e.g., T312) are configured and run, the UE does not check the elapsed timer values of them for logging SHR.

In this example, if the third threshold is configured by the target BS, after the target BS receives the SHR, it will not forward the SHR to the source BS.

In some embodiments according to the present disclosure, the UE may receive more than one trigger conditions for SHR, i.e., the UE may receive more than one of the first threshold, the second threshold, and the third threshold. In this case, during the HO, it is possible that at least two trigger conditions may be met.

The present disclosure provides various methods for logging SHR in the cases that the UE receives more than one trigger conditions and possibly more than one trigger conditions are met.

Figure 4 illustrates an exemplary flowchart of method 400 based on method 100 according to some embodiments of the present disclosure.

In operation 410, the UE receives more than one trigger conditions for SHR from a source BS via an RRC reconfiguration message. The trigger conditions are more than one of the first threshold, the second threshold, or the third threshold.

In operation 420, the UE performs HO upon reception of an HO command or upon a CHO condition being met.

In operation 430, the UE determines whether any of the received trigger conditions is met during HO.

In operation 440, the UE logs parameters for a SHR associated with a latest met trigger condition of the more than one trigger conditions.

In some embodiments, the UE may transmit the SHR to the target BS. In some embodiments, the UE may first transmit an indicator indicating availability of the SHR and/or the latest met trigger condition to the target BS after accessing to the target BS, if the BS needs the SHR, it may transmit a UE information request message, then the UE transmits the SHR to the target BS via a UE information response message.

For example, in operation 410, the UE receives an RRC reconfiguration message (e.g., RRCReconfiguration) including a first threshold for a physical layer problem timer (e.g., T310) and a third threshold for a handover timer (e.g., T304) .

In this example, the first configured value for the physical layer problem timer is 500ms, the third configured value for the handover timer is 1000ms, the first threshold is 60%, and the third threshold is 40%; i.e., the first threshold multiplied with the first configured value for the physical layer problem timer is 300ms, the third threshold multiplied with the third configured value for the handover timer is 400ms.

In operation 420, the UE starts the handover timer and performs HO.

In operation 430, during the HO, the UE determines whether the elapsed time value of the physical layer problem timer is greater than 300ms, and whether the elapsed time value of the handover timer is greater than 400ms.

In this example, the UE first determines that the first threshold is met, and later determines that the third threshold is met; i.e., the third threshold is the latest met trigger condition. Then in operation 440, the UE logs parameters for a SHR associated with the third threshold, the logged parameters are referred to be associated with the third threshold.

In this example, the UE transmits the SHR associated with the third threshold. In some embodiments, the UE may transmit an indicator to the target BS after the UE accesses to the target BS; the indicator indicates availability of the SHR; furthermore, the indicator also indicates that the met trigger condition is the third threshold. In some embodiments, if the target BS needs the at least one SHR, it may send a UE information request message to the UE; upon reception of the UE information request message, the UE may transmit the at least one SHR to the target BS via a UE information response message.

In this example, the UE does not receive the second threshold; therefore, even if the timer for initiating failure recovery based on triggering a measurement report (e.g., T312) is configured and runs, the UE does not check the elapsed timer values of it for logging SHR.

In this example, if the third threshold is configured by the target BS; even if the target BS receives the SHR, it will not forward the SHR to the source BS.

In some embodiments, in a variant of operation 440 of method 400, the UE logs parameters for a first SHR associated with a first met trigger condition of the more than one trigger conditions; in other words, the UE logs parameters for a first SHR in response to a trigger condition of the more than one trigger condition which is met first. If the UE determines that another trigger condition of the more than one trigger condition is met later, the UE discards the first SHR, and log parameters for a second SHR associated with the second met trigger condition of the more than one trigger condition; in other words, the UE logs parameters in response to a trigger condition being met earlier, discards parameters in response to a trigger condition being met later, logs parameters associated with the met later trigger condition, till accessing to the target BS. The UE may store a SHR including parameters associated with the latest met trigger condition, and may transmit the SHR to the target BS.

For example, in operation 410, the UE receives an RRC reconfiguration message (e.g., RRCReconfiguration) including a first threshold for a physical layer problem timer (e.g., T310) , a second threshold for a timer (e.g., T312) for initiating failure recovery based on triggering a measurement report, and a third threshold for a handover timer (e.g., T304) .

In operation 440, if a trigger condition, e.g., the first threshold is met first, the UE logs parameters for a first SHR associated with the first threshold; if a trigger condition, e.g., the third threshold is met later, the UE discards the first SHR and logs parameters for a second SHR associated with the third threshold; and if a trigger condition, e.g., the second threshold is met at last, the UE discards the second SHR and logs parameters for a third SHR. At last, the UE only stores the third SHR, and may transmit the third SHR to the target BS.

In this example, the UE may transmit the SHR to the target BS. The UE may first transmit an indicator indicating availability of the SHR and/or the latest met trigger condition (i.e., the second threshold) to the target BS after accessing to the target BS, if the BS needs the SHR, it may transmit a UE information request message, then the UE transmits the SHR to the target BS via a UE information response message.

Figure 5 illustrates an exemplary flowchart of method 500 based on method 100 according to some embodiments of the present disclosure.

In operation 510, the UE receives more than one trigger conditions for SHR from a source BS via an RRC reconfiguration message. The trigger conditions include more than one of the first threshold, the second threshold, or the third threshold.

In operation 520, the UE performs HO upon reception of an HO command or upon a CHO condition being met.

In operation 530, the UE determines whether any of the received trigger conditions is met during HO.

In operation 540, the UE logs parameters for a SHR in response to a trigger condition being met first; i.e., the UE logs parameters associated with the first met trigger condition for a SHR. In some embodiments, the UE may transmit the SHR including the parameters to the target BS.

In some embodiments, the UE may transmit the SHR to the target BS. In some embodiments, the UE may first transmit an indicator indicating availability of the SHR and/or the first met trigger condition to the target BS after accessing to the target BS, if the BS needs the SHR, it may transmit a UE information request message, then the UE transmits the SHR to the target BS via a UE information response message.

In some embodiments of operation 540, if the UE determines that a trigger condition is met first, i.e., if the UE determines the first met trigger condition, the UE logs parameters associated with the first met trigger condition for a SHR, and will not check whether there is any other trigger condition is met later.

For example, in operation 510, the UE receives an RRC reconfiguration message (e.g., RRCReconfiguration) including a first threshold for a physical layer problem timer (e.g., T310) , a second threshold for a timer (e.g., T312) for initiating failure recovery based on triggering a measurement report, and a third threshold for a handover timer (e.g., T304) .

Then in operation 540, if a trigger condition (e.g., the first threshold) is first met, the UE logs parameters for a SHR associated with the first threshold; after that, the UE do not check whether the second threshold and the third threshold are met later. At last, the UE only stores the SHR including parameters associated with the first threshold.

In this example, the UE may transmit the SHR to the target BS after accessing to the target BS. In some embodiments, the UE may first transmit an indicator indicating availability of the SHR and/or the first met trigger condition (i.e., the first threshold) to the target BS after accessing to the target BS, if the BS needs the SHR, it may transmit a UE information request message, then the UE transmits the SHR to the target BS via a UE information response message.

In some embodiments of operation 540, if the UE determines a first met trigger condition, the UE logs parameters for a SHR associated with the first met trigger condition, the UE will continue to check whether there is any other trigger condition is met later, but it will not log any parameters associated with any other trigger condition met later.

For example, in operation 510, the UE receives an RRC reconfiguration message (e.g., RRCReconfiguration) ; herein the RRC reconfiguration message includes a first threshold for a physical layer problem timer (e.g., T310) , a second threshold for a timer (e.g., T312) for initiating failure recovery based on triggering a measurement report, and a third threshold for a handover timer (e.g., T304) .

Then in operation 540, if a trigger condition, e.g., the first threshold is first met, the UE logs parameters for a SHR associated with the first threshold; after that, the UE continue to check whether the second threshold and the third threshold are met later. In this example, the UE determines that the second threshold is met later. However, the UE does not log any parameters in response to the second threshold being met later. At last, the UE only stores the SHR including parameters associated with the first threshold.

In this example, the UE may transmit the SHR to the target BS. In some embodiments, the UE may first transmit an indicator indicating availability of the SHR and/or the latest met trigger condition (i.e., the first threshold) to the target BS after accessing to the target BS, if the BS needs the SHR, it may transmit a UE information request message, then the UE transmits the SHR to the target BS via a UE information response message.

Figure 6 illustrates an exemplary flowchart of method 600 based on method 100 according to some embodiments of the present disclosure.

In operation 610, the UE receives more than one trigger conditions for SHR from a source BS via an RRC reconfiguration message. The trigger conditions include more than one of the first threshold, the second threshold, or the third threshold.

In operation 620, the UE performs HO upon reception of an HO command or upon a CHO condition being met.

In operation 630, the UE determines whether any of the received more than one trigger conditions is met during HO.

In operation 640, the UE logs a set of parameters in a same SHR for each met trigger condition.

In some embodiments, the UE may transmit the SHR including all the sets of parameters to the target BS. In some embodiments, the UE may first transmit an indicator indicating availability of the SHR and/or all the met trigger condition (s) to the target BS after accessing to the target BS, if the BS needs the SHR, it may transmit a UE information request message, then the UE transmits the SHR to the target BS via a UE information response message.

For example, in operation 610, the UE receives an RRC reconfiguration message (e.g., RRCReconfiguration) including a first threshold for a physical layer problem timer (e.g., T310) , a second threshold for a timer (e.g., T312) for initiating failure recovery based on triggering a measurement report, and a third threshold for a handover timer (e.g., T304) .

Then in operation 640, if a trigger condition, e.g., the first threshold is first met, the UE logs a first set of parameters in a SHR associated with the first threshold; if a trigger condition, e.g., the second threshold is second met, the UE logs a second set of parameters in the same SHR. After the UE access the target BS, the UE may transmit the SHR to the target BS; herein, the SHR includes the first set of parameters associated with the first trigger condition and the second set of parameters associated with the second trigger condition.

In this example, the UE may transmit the SHR to the target BS. In some embodiments, the UE may first transmit an indicator indicating availability of the SHR and/or all the met trigger conditions (the first threshold and the second threshold) to the target BS after accessing to the target BS, if the BS needs the SHR, it may transmit a UE information request message, then the UE transmits the SHR to the target BS via a UE information response message.

Figure 7 illustrates an exemplary flowchart of method 700 based on method 100 according to some embodiments of the present disclosure.

In operation 710, the UE receives more than one trigger conditions for SHR from a source BS via an RRC reconfiguration message. The trigger conditions include more than one of the first threshold, the second threshold, or the third threshold.

In operation 720, the UE performs HO upon reception of an HO command or upon a CHO condition being met.

In operation 730, the UE determines whether any of the received more than one trigger conditions is met during HO.

In operation 740, the UE logs a set of parameters in a separate SHR for each met trigger condition.

In some embodiments, the UE may transmit all the SHR (s) to the target BS. In some embodiments, the UE may first transmit an indicator indicating availability of all the SHR (s) and/or all the met trigger condition (s) to the target BS after accessing to the target BS, if the BS needs the SHR, it may transmit a UE information request message, then the UE transmits all the SHR (s) to the target BS via a UE information response message.

For example, in operation 710, the UE receives an RRC reconfiguration message (e.g., RRCReconfiguration) ; herein the RRC reconfiguration message includes a first threshold for a physical layer problem timer (e.g., T310) , a second threshold for a timer (e.g., T312) for initiating failure recovery based on triggering a measurement report, and a third threshold for a handover timer (e.g., T304) .

Then in operation 740, if a trigger condition, e.g., the second threshold is first met, the UE logs a first set of parameters in a first SHR associated with the second threshold; if a trigger condition, e.g., the third threshold is second met, the UE logs a second set of parameters in a second SHR associated with the third threshold.

In this example, the UE may transmit the first SHR and the second SHR to the target BS. In some embodiments, the UE may first transmit an indicator indicating availability of the first SHR and the second SHR, and/or all the met trigger conditions (the second threshold and the third threshold) to the target BS after accessing to the target BS, if the BS needs the SHR, it may transmit a UE information request message, then the UE transmits all the SHR (s) to the target BS via a UE information response message.

The above provide various methods performed on UE side for generating at least one SHR including at least one set of parameters associated with at least one met trigger condition. It would be appreciated that the target BS and the source BS performs corresponding methods according to the present disclosure.

Figure 8 illustrates an exemplary flowchart of method 800 performed by a target BS according to some embodiments of the present disclosure. It would be appreciated that in method 800 or in other methods described later, the target BS is not a special BS; it can be a generic device or an apparatus, or a part of a device or an apparatus that uses the technical solution of the present application.

In operation 810, the target BS transmits an HO request acknowledge (e.g., handover request acknowledge message 250) to a source BS.

In operation 820, the target BS receives an indicator indicating availability of at least one SHR from a UE and/or at least one met trigger condition, wherein the at least one SHR including at least one set parameters associated with at least one trigger condition that is met during HO. In some embodiment, the indicator may be transmitted in a HO complete message (e.g., RRCReconfigurationComplete) over RRC. In some embodiments, the indicator further indicates the at least one met trigger condition.

In some embodiments, the at least one trigger condition comprises at least one of: a first threshold of a physical layer problem timer (e.g., T310) , a second threshold for a timer (e.g., T312) for initiating failure recovery based on triggering a measurement report, or a third threshold for a handover timer (e.g., T304) .

In some embodiments, method 800 further includes transmitting an indicator to the source BS indicating whether the third threshold is configured by the target BS. If the third threshold is configured by the target BS, method 800 further includes transmitting the third threshold via the HO request acknowledge to the source BS, wherein the indicator indicates that the third threshold is configured by the target BS.

In some embodiments, method 800 further includes receiving the at least one SHR form the UE. In some embodiment, after the target BS receives the indicator indicating availability of the at least one SHR and/or at least one met trigger condition, if the target BS needs the at least one SHR, it may send a UE information request message (e.g., UEInformationRequest) to the UE; upon reception of the UE information request message, the UE may transmit the at least one SHR to the target BS via a UE information response message (e.g., UEInformationResponse) .

In some embodiments, method 800 further includes forwarding the received at least one SHR to the source BS. In some embodiments, the target BS may further indicates to the source BS which trigger condition (s) are met. The network may optimize its mobility and robustness at least based on the at least one SHR.

In some embodiments, if the third threshold is configured by the target BS, the third threshold is met during the HO (i.e., an elapsed time value of the handover timer is greater than the third threshold multiplied with a configured value for the handover timer at the UE side during the HO) , and a received SHR includes the parameters associated with the third threshold, the target BS may remove the parameters associated with the third threshold from a received SHR before transferring the received SHR to the source BS, or the target BS does not transmit a received SHR only including the parameters associated with the third threshold to the source BS; furthermore, the target BS will not notify the source BS that the third threshold is met during the HO.

Figure 9 illustrates an exemplary flowchart of method 900 performed by a source BS according to some embodiments of the present disclosure. It would be appreciated that in method 900 or in other methods described later, the source BS is not a special BS; it can be a generic device or an apparatus, or a part of a device or an apparatus that uses the technical solution of the present application.

In operation 910, the source BS receives an HO request acknowledge from a target BS.

In operation 920, the source BS transmits at least one trigger condition for SHR via an RRC reconfiguration message to a UE.

In operation 930, the source BS transmits an HO command or a CHO configuration to the UE.

In some embodiments, the first threshold and the second threshold are configured by the source BS, and the third threshold is configured by the source BS or the target BS.

In some embodiments, method 900 further includes receiving an indicator from the target BS indicating whether the third threshold is configured by the target BS. If the third threshold is configured by the target BS, method 900 further includes receiving the third threshold via the HO request acknowledge from the target BS, wherein the indicator indicates that the third threshold is configured by the target BS.

In some embodiments, method 900 further includes receiving the at least one SHR form the UE. In some embodiments, the target BS may further notify the source BS the met trigger condition (s) .

In some embodiments, if the third threshold is configured by the target BS, even if the third threshold is met during the HO (i.e., an elapsed time value of the handover timer is greater than the third threshold multiplied with a configured value for the handover timer at the UE side during the HO) , the source BS will not receive any parameters for SHR associated with the third threshold; furthermore, the source BS will not be notified that the third threshold is met during the HO even if the third threshold is met during the HO.

It would be appreciated in the provided methods and embodiments provided by the present disclosure, the number of each operation does not represent the order of execution.

The present disclosure provides definitions for one or more trigger conditions for SHR.

The present disclosure provides various methods and embodiments for how to report SHR (s) if one or more trigger conditions for SHR are configured.

The present disclosure provides various methods and embodiments for forwarding SHR (s) from a target BS to a source BS if a third threshold of a handover timer (e.g., T304) is configured, wherein the third threshold is configured by a source BS or a target BS.

Figure 10 illustrates a simplified block diagram of an exemplary apparatus 1000 according to various embodiments of the present disclosure. Apparatus 1000 may be or include at least a part of a UE or similar device having similar functionality.

As shown in Figure 10, apparatus 1000 may include at least wireless transceiver 1010 and processor 1020, wherein wireless transceiver 1010 may be coupled to processor 1020. Furthermore, apparatus 1000 may include non-transitory computer-readable medium 1030 with computer-executable instructions 1040 stored thereon, wherein non-transitory computer-readable medium 1030 may be coupled to processor 1020, and computer-executable instructions 1040 may be configured to be executable by processor 1020. In some embodiments, wireless transceiver 1010, non-transitory computer-readable medium 1030, and processor 1020 may be coupled to each other via one or more local buses.

Although in Figure 10, elements such as wireless transceiver 1010, non-transitory computer-readable medium 1030, and processor 1020 are described in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the wireless transceiver 1010 may be configured for wireless communication. In some embodiments of the present disclosure, wireless transceiver 1010 can be integrated into a transceiver. In certain embodiments of the present disclosure, the apparatus 1000 may further include other components for actual usage.

Processor 1020 is configured to cause the apparatus 1000 at least to perform, with wireless transceiver 1010, any one of the various methods (e.g., method 100) and embodiments described above which are performed by a UE according to the present disclosure.

According to the present disclosure, processor 1020 is configured to, with wireless transceiver 1010, receive at least one trigger condition for SHR from a source BS via an RRC reconfiguration message; perform HO upon reception of a HO command or upon a CHO condition being met; determine whether the at least one trigger condition is met during HO; and log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO.

In some embodiments, processor 1020 is further configured to transmit, with wireless transceiver 1010, an indicator indicating availability of the at least one SHR after accessing to the target BS.

In some embodiments, processor 1020 is further configured to: receive, with wireless transceiver 1010, a UE information request from the target BS; and transmit, with the wireless transceiver, UE information response including at least one SHR to the target BS.

In some embodiments, the at least one trigger condition comprises at least one of: a first threshold of a physical layer problem timer, a second threshold for a timer for initiating failure recovery based on triggering a measurement report, or a third threshold for a handover timer, and the processor 1020 is configured to log parameters for SHR in response to at least one of the followings: an elapsed time value of the physical layer problem timer being greater than the first threshold multiplied with a first configured value for the physical layer problem timer; an elapsed time value of the timer for initiating failure recovery based on triggering a measurement report being greater than the second threshold multiplied with a second configured value for the timer for initiating failure recovery based on triggering a measurement report; or an elapsed time value of the handover timer being greater than the third threshold multiplied with a third configured value for the handover timer.

In some embodiment, to receive the at least one trigger condition, processor 1020 is further configured to receive, with wireless transceiver 1010, only one trigger condition, and to log the parameters for the at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to log the parameters for a SHR in response to the one trigger condition being met.

In some embodiments, to receive the at least one trigger condition, processor 1020 is further configured to receive, with wireless transceiver 1010, more than one trigger conditions.

In some embodiments, processor 1020 is further configured to: log parameters for the SHR associated with a latest met trigger condition of the more than one trigger conditions; and transmit, with wireless transceiver 1010, a SHR including the parameters to target BS.

In some embodiments, processor 1020 is further configured to: log the parameters for a first SHR associated with a first met trigger condition of the more than one trigger conditions; discard the first SHR and logging the parameters for a second SHR associated with a second met trigger condition of the more than one trigger conditions; and transmit, with wireless transceiver 1010, a second SHR to the target BS.

In some embodiments, processor 1020 is further configured to: log parameters for SHR associated with a first met trigger condition of the more than one trigger conditions without further checking whether at least one other trigger condition of the more than one trigger conditions is met later; and transmit, with wireless transceiver 1010, a SHR including the parameters.

In some embodiments, processor 1020 is further configured to: log parameter associated with a first met trigger condition of the more than one trigger conditions without logging parameters associated with at least one other trigger condition of the more than one trigger conditions which is even met later; and transmit, with wireless transceiver 1010, a SHR including the parameters.

In some embodiments, to log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO, processor 1020 is further configured to: log a first set of parameters associated with a first met trigger condition of the more than one trigger conditions; log a second set of parameters associated with a second met trigger condition; and transmit, with wireless transceiver 1010, one single SHR including the first set parameters and the second set parameters.

In some embodiments, to log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO, processor 1020 is further configured to: log a first set of parameters associated with a first met trigger condition of the more than one trigger conditions; log a second set of parameters associated with a second met trigger condition of the more than one trigger conditions; and transmit, with wireless transceiver 1010, separate SHRs including the first set of parameters and the second set of parameters respectively.

Figure 11 illustrates a simplified block diagram of an exemplary apparatus 1100 according to various embodiments of the present disclosure. Apparatus 1100 may be a target BS, or include at least a part of a target BS, or a device having similar functionality.

As shown in Figure 11, apparatus 1100 may include at least wireless transceiver circuitry 1110 and processor 1120, wherein wireless transceiver 1110 may be coupled to processor 1120. Furthermore, apparatus 1100 may include non-transitory computer-readable medium 1130 with computer-executable instructions 1140 stored thereon, wherein non-transitory computer-readable medium 1130 may be coupled to processor 1120, and computer-executable instructions 1140 may be configured to be executable by processor 1120. In some embodiments, wireless transceiver 1110, non-transitory computer-readable medium 1130, and processor 1120 may be coupled to each other via one or more local buses.

Although in Figure 11, elements such as wireless transceiver 1110, non-transitory computer-readable medium 1130, and processor 1120 are described in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the wireless transceiver 1110 may be configured for wireless communication. In some embodiments of the present disclosure, wireless transceiver 1110 can be integrated into a transceiver. In certain embodiments of the present disclosure, the apparatus 1100 may further include other components for actual usage.

Processor 1120 is configured to cause the apparatus 1100 at least to perform, with wireless transceiver 1110, any one of the various methods (e.g., method 800) and embodiments described above which are performed by a target BS according to the present disclosure.

According to the present disclosure, processor 1120 is configured to, transmit, with wireless transceiver 1110, a HO request acknowledge to a source BS; receive, with wireless transceiver 1110, an indicator indicating availability of at least one SHR from a UE, wherein the at least one SHR including at least one set parameters associated with at least one trigger condition that is met during HO.

In some embodiments, processor 1120 is further configured to transmit, with wireless transceiver 1110, an indicator to the source BS indicating whether the third threshold is configured by the target BS.

In some embodiments, processor 1120 is further configured to transmit, with wireless transceiver 1110, the third threshold via the HO request acknowledge to the source BS, wherein the indicator indicates that the third threshold is configured by the target BS.

In some embodiments, processor 1120 is further configured to: transmit, with wireless transceiver 1110, a UE information request to the UE; and receive, with wireless transceiver 1110, the at least one SHR from the UE.

In some embodiments, processor 1120 is further configured to transfer, with wireless transceiver 1110, the received at least one SHR to the source BS.

In some embodiments, processor 1120 is further configured to: remove parameters associated with the third threshold from the at least one received SHR before transferring the received at least one SHR, in response to: the third threshold is configured by the target BS; an elapsed time value of the handover timer being greater than the third threshold multiplied with a configured value for the handover timer at the UE; and the set of parameters associated with the third threshold are logged in the at least one SHR.

Figure 12 illustrates a simplified block diagram of an exemplary apparatus 1200 according to various embodiments of the present disclosure. Apparatus 1200 may be a source BS, or include at least a part of a source BS, or a device having similar functionality.

As shown in Figure 12, apparatus 1200 may include at least wireless transceiver circuitry 1210 and processor 1220, wherein wireless transceiver 1210 may be coupled to processor 1220. Furthermore, apparatus 1200 may include non-transitory computer-readable medium 1230 with computer-executable instructions 1240 stored thereon, wherein non-transitory computer-readable medium 1230 may be coupled to processor 1220, and computer-executable instructions 1240 may be configured to be executable by processor 1220. In some embodiments, wireless transceiver 1210, non-transitory computer-readable medium 1230, and processor 1220 may be coupled to each other via one or more local buses.

Although in Figure 12, elements such as wireless transceiver 1210, non-transitory computer-readable medium 1230, and processor 1220 are described in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the wireless transceiver 1210 may be configured for wireless communication. In some embodiments of the present disclosure, wireless transceiver 1210 can be integrated into a transceiver. In certain embodiments of the present disclosure, the apparatus 1200 may further include other components for actual usage.

Processor 1220 is configured to cause the apparatus 1200 at least to perform, with wireless transceiver 1210, any one of the various methods (e.g., method 900) and embodiments described above which are performed by a source BS according to the present disclosure.

According to the present disclosure, processor 1220 is configured to, receive, with wireless transceiver 1210, a HO request acknowledge from a target BS; transmit, with wireless transceiver 1210, at least one trigger condition for SHR via an RRC reconfiguration message to a UE; and transmit, with wireless transceiver 1210, an HO command or a CHO configuration to the UE.

In some embodiments, processor 1220 is further configured to: receive, with wireless transceiver 1210, an indicator from the target BS indicating whether the third threshold for the HO timer is configured by the target BS; and receive, with wireless transceiver 1210, the third threshold for the HO timer via the HO request acknowledge in response to that the indicator indicating the third threshold is configured by the target BS.

In some embodiments, processor 1220 is further configured to receive, with wireless transceiver 1210, at least one SHR from the target BS including at least one set of parameters associated with at least one trigger condition that is met during a HO.

In various example embodiments,

processors

1020, 1120, or 1220 may include, but is not limited to, at least one hardware processor, including at least one microprocessor such as a CPU, a portion of at least one hardware processor, and any other suitable dedicated processor such as those developed based on for example Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuit (ASIC) . Further,

processors

1020, 1120, or 1220 may also include at least one other circuitry or element not shown in Figure 10, Figure 11, or Figure 12.

In various example embodiments, non-transitory computer-

readable mediums

1030, 1130, or 1230 may include at least one storage medium in various forms, such as a volatile memory and/or a non-volatile memory. The volatile memory may include, but is not limited to, for example, an RAM, a cache, and so on. The non-volatile memory may include, but is not limited to, for example, an ROM, a hard disk, a flash memory, and so on. Further, non-transitory computer-

readable mediums

1030, 1130, or 1230 may include, but is not limited to, an electric, a magnetic, an optical, an electromagnetic, an infrared, or a semiconductor system, apparatus, or device or any combination of the above.

Further, in various example embodiments,

exemplary apparatus

1000, 1100, or 1200 may also include at least one other circuitry, element, and interface, for example antenna element, and the like.

In various example embodiments, the circuitries, parts, elements, and interfaces in

exemplary apparatus

1000, 1100, or 1200, including

processor

1020, 1120, or 1220 and non-transitory computer-

readable mediums

1030, 1130, or 1230, may be coupled together via any suitable connections including, but not limited to, buses, crossbars, wiring and/or wireless lines, in any suitable ways, for example electrically, magnetically, optically, electromagnetically, and the like.

The methods 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.

The terms "includes, " "comprising, " "includes, " "including, " or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes 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 includes 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 processor; and

a wireless transceiver coupled to the processor,

wherein the processor is configured to:

receive, with the wireless transceiver, at least one trigger condition for successful handover report (SHR) from a source base station (BS) via a radio resource control (RRC) reconfiguration message;

perform handover (HO) upon reception of a HO command or upon a conditional handover (CHO) condition being met;

determine whether the at least one trigger condition is met during HO; and

log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO.
The UE of Claim 1, wherein the processor is further configured to:

transmit, with the wireless transceiver, an indicator indicating availability of the at least one SHR after accessing to the target BS.
The UE of Claim 2, wherein the processor is further configured to:

receive, with the wireless transceiver, a UE information request from the target BS; and

transmit, with the wireless transceiver, UE information response including at least one SHR to the target BS.
The UE of Claim 1, wherein the at least one trigger condition comprises at least one of: a first threshold of a physical layer problem timer, a second threshold for a timer for initiating failure recovery based on triggering a measurement report, or a third threshold for a handover timer, and wherein the processor is configured to log parameters for SHR in response to at least one of the followings:

an elapsed time value of the physical layer problem timer being greater than the first threshold multiplied with a first configured value for the physical layer problem timer;

an elapsed time value of the timer for initiating failure recovery based on triggering a measurement report being greater than the second threshold multiplied with a second configured value for the timer for initiating failure recovery based on triggering a measurement report; or

an elapsed time value of the handover timer being greater than the third threshold multiplied with a third configured value for the handover timer.
The UE of Claim 4, wherein the first threshold and the second threshold are configured by a source BS, and the third threshold is configured by the source BS or the target BS.
The UE of Claim 4, wherein:

to receive the at least one trigger condition, the processor is further configured to receive, with the wireless transceiver, only one trigger condition, and

to log the parameters for the at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to log the parameters for a SHR in response to the one trigger condition being met.
The UE of Claim 4, wherein

to receive the at least one trigger condition, the processor is further configured to receive, with the wireless transceiver, more than one trigger conditions.
The UE of Claim 7, wherein to log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to:

log parameters for the SHR associated with a latest met trigger condition of the more than one trigger conditions; and

transmit, with the wireless transceiver, a SHR including the parameters to target BS.
The UE of Claim 7, wherein to log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to:

log the parameters for a first SHR associated with a first met trigger condition of the more than one trigger conditions;

discard the first SHR and logging the parameters for a second SHR associated with a second met trigger condition of the more than one trigger conditions; and

transmit, with the wireless transceiver, a second SHR to the target BS.
The UE of Claim 7, wherein to log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to:

log parameters for SHR associated with a first met trigger condition of the more than one trigger conditions without further checking whether at least one other trigger condition of the more than one trigger conditions is met later; and

transmit, with the wireless transceiver, a SHR including the parameters.
The UE of Claim 7, wherein to log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to:

log parameter associated with a first met trigger condition of the more than one trigger conditions without logging parameters associated with at least one other trigger condition of the more than one trigger conditions which is even met later; and

transmit, with the wireless transceiver, a SHR including the parameters.
The UE of Claim 7, wherein to log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to:

log a first set of parameters associated with a first met trigger condition of the more than one trigger conditions;

log a second set of parameters associated with a second met trigger condition; and

transmit, with the wireless transceiver, one single SHR including the first set parameters and the second set parameters.
The UE of Claim 7, wherein to log the parameters for at least one SHR in response to that the at least one trigger condition is met during HO, the processor is further configured to:

log a first set of parameters associated with a first met trigger condition of the more than one trigger conditions;

log a second set of parameters associated with a second met trigger condition of the more than one trigger conditions; and

transmit, with the wireless transceiver, separate SHRs including the first set of parameters and the second set of parameters respectively.
A target base station (BS) , comprising:

a processor; and

a wireless transceiver coupled to the processor,

wherein the processor is configured to:

transmit, with the wireless transceiver, a handover (HO) request acknowledge to a source BS;

receive, with the wireless transceiver, an indicator indicating availability of at least one successful handover report (SHR) from a user equipment (UE) , wherein

the at least one SHR including at least one set parameters associated with at least one trigger condition that is met during HO.
The target BS of Claim 14, wherein the at least one trigger condition comprises at least one of: a first threshold of a physical layer problem timer, a second threshold for a timer for initiating failure recovery based on triggering a measurement report, or a third threshold for a handover timer.