WO2024239683A1

WO2024239683A1 - Methods and apparatuses for a prediction operation related to a failure or an abnormal handover

Info

Publication number: WO2024239683A1
Application number: PCT/CN2024/072797
Authority: WO
Inventors: Lianhai WU; Le Yan; Lihua Yang
Original assignee: Lenovo Beijing Ltd
Current assignee: Lenovo Beijing Ltd
Priority date: 2024-01-17
Filing date: 2024-01-17
Publication date: 2024-11-28
Anticipated expiration: 2026-07-17

Abstract

Various aspects of the present disclosure relate to methods and apparatuses for a prediction operation related to a failure or an abnormal handover. According to an embodiment of the present disclosure, user equipment (UE) includes at least one memory and at least one processor coupled to the at least one memory and configured to cause the UE to: receive, from a serving cell of the UE, configuration information used for the UE to predict at least one of the following: a radio link failure (RLF); a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and perform a prediction operation based on the configuration information.

Description

METHODS AND APPARATUSES FOR A PREDICTION OPERATION RELATED TO A FAILURE OR AN ABNORMAL HANDOVER

TECHNICAL FIELD

The present disclosure relates to wireless communications, and more specifically to methods and apparatuses for a prediction operation related to a failure (e.g. a radio link failure (RLF) ) or an abnormal handover.

BACKGROUND

A wireless communications system may include one or multiple network communication devices, such as base stations, which may support wireless communications for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communications system may support wireless communications with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g. time-domain resources (e.g. symbols, slots, subframes, frames, or the like) or frequency-domain resources (e.g. subcarriers, carriers, or the like) . Additionally, the wireless communications system may support wireless communications across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) radio access technology, among other suitable radio access technologies beyond 5G (e.g. sixth generation (6G) ) .

SUMMARY

An article "a" before an element is unrestricted and understood to refer to "at least one" of those elements or "one or more" of those elements. The terms "a, " "at least one, " "one or more, " and "at least one of one or more" may be interchangeable. As used herein, including in the claims, "or" as used in a list of items (e.g. a list of items prefaced by a phrase such as "at least one of" or "one or more of" or "one or both of" ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase "based on" shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as "based on condition A" may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" shall be construed in the same manner as the phrase "based at least in part on. Further, as used herein, including in the claims, a "set" may include one or more elements.

Some implementations of the present disclosure provide a user equipment (UE) . The UE includes at least one memory; and at least one processor coupled to the at least one memory and configured to cause the UE to: receive, from a serving cell of the UE, configuration information used for the UE to predict at least one of the following: a radio link failure (RLF) ; a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and perform a prediction operation based on the configuration information.

In some implementations of the UE described herein, the processor of the UE is configured to report, to the serving cell, capability regarding whether to support the prediction operation related to at least one of the RLF, the ping-pong handover or the short of stay after the handover. The ping-pong handover means the UE hands over back to the source cell (e.g. the serving cell) after the UE hands over to the candidate cell. The short of stay means the UE hands over to another cell after the short of time since the UE hands over to the candidate cell.

In some implementations of the UE described herein, the processor of the UE is configured to receive, from the serving cell, a configuration regarding a threshold of a channel quality of the serving cell to trigger to perform the prediction operation.

In some implementations of the UE described herein, the processor of the UE is configured to: deliver, by an access stratum (AS) layer of the UE to an upper layer or an artificial intelligence (AI) entity of the UE, information indicating to perform the prediction operation if the channel quality of the serving cell is less than the configured threshold.

In some implementations of the UE described herein, the processor of the UE is configured to: deliver, by an access stratum (AS) layer of the UE to an upper layer or an artificial intelligence (AI) entity of the UE, one or more measurement results of the serving cell; and determine, by the upper layer or the AI entity of the UE, whether to start or stop performing the prediction operation based on the one or more measurement results.

In some implementations of the UE described herein, the processor of the UE is configured to receive at least one of the following from the serving cell: a first configuration regarding first time duration used to predict whether the RLF will occur; a second configuration regarding second time duration used to predict whether the ping-pong handover towards a candidate cell will occur; a configuration regarding a first threshold used to predict whether the ping-pong handover will occur; or a configuration regarding a second threshold used to predict whether the short of stay after the handover will occur.

In some implementations of the UE described herein, the first configuration includes information of a first timer related to the first time duration, wherein start time of the first timer is a time point of receiving the first configuration or an absolute time point, and wherein the processor of the UE is configured to: start performing the prediction operation related to the RLF at the start time of the first timer; and stop performing the prediction operation related to the RLF upon an expiry of the first timer.

In some implementations of the UE described herein, the second configuration includes information of a second timer related to the second time duration, wherein start time of the second timer is a time point of receiving the second configuration or an absolute time point, and wherein the processor of the UE is configured to: start performing the prediction operation related to the ping-pong handover at the start time of the second timer; and stop performing the prediction operation related to the ping-pong handover upon an expiry of the second timer.

In some implementations of the UE described herein, the processor of the UE is configured to: predict that the ping-pong handover will occur if a time period staying at the at least one candidate cell is less than the first threshold; or predict that the short of stay will occur if a time period staying at the at least one candidate cell after the handover is less than the second threshold.

In some implementations of the UE described herein, in response to predicting that at least one of the RLF, the ping-pong handover, or the short of stay after the handover will occur, the processor of the UE is configured to transmit a prediction report to the serving cell.

In some implementations of the UE described herein, in response to predicting that the RLF will occur in the serving cell, the prediction report includes at least one of the following: information indicating that the RLF is predicted to occur in the serving cell; a time point at or after which the RLF is predicted to occur in the serving cell; a time window within which the RLF is predicted to occur in the serving cell; or a predicted failure cause of the RLF in the serving cell.

In some implementations of the UE described herein, in response to predicting that the ping-pong handover will occur, the prediction report includes at least one of the following: information indicating that the ping-pong handover is predicted to occur if the UE switches to a candidate cell; or a time window, wherein the UE is predicted to switch from the candidate cell back to the serving cell if the UE switches from the serving cell to the candidate cell within the time window.

In some implementations of the UE described herein, in response to predicting that the short of stay after the handover will occur, the prediction report includes at least one of the following: information indicating that the short of stay after the handover is predicted to occur if the UE switches to a candidate cell; a candidate cell list, wherein the candidate cell list includes a first candidate cell, and the short of stay is predicted to occur at the first candidate cell after the UE switches to the first candidate cell; or a time duration list, wherein the time duration list includes third time duration, and the UE is predicted to stay at the first candidate cell during the third time duration after the UE switches from the serving cell to the first candidate cell and before the UE switches from the first candidate cell to another candidate cell.

In some implementations of the UE described herein, the processor of the UE is configured to: trigger to execute a handover from the serving cell; and in response to triggering the handover, stop performing the prediction operation related to the RLF for the serving cell.

In some implementations of the UE described herein, the processor of the UE is configured to deliver, by an access stratum (AS) layer of the UE to an upper layer or an artificial intelligence (AI) entity of the UE, information indicating to stop performing the prediction operation in response to triggering the handover.

In some implementations of the UE described herein, to stop the prediction operation, the processor of the UE is configured to stop a timer used to predict whether the RLF will occur if the timer is running.

In some implementations of the UE described herein, the processor of the UE is configured to: receive a radio resource control (RRC) reconfiguration message from a candidate cell; and if the RRC reconfiguration message includes a configuration used to predict whether the RLF will occur, start performing the prediction operation related to the RLF for the candidate cell after the UE switches to the candidate cell.

In some implementations of the UE described herein, the processor of the UE is configured to: in response to predicting that the RLF will occur in the candidate cell, transmit, to the candidate cell, information indicating that the RLF is predicted to occur in the candidate cell.

In some implementations of the UE described herein, the information is transmitted to the candidate cell via an RRC reconfiguration complete message or a handover complete message.

In some implementations of the UE described herein, the processor of the UE is configured to: trigger to execute a handover from the serving cell; and in response to triggering the handover, stop performing the prediction operation related to the ping-pong handover towards at least one candidate cell or the short of stay at the at least one candidate cell after the handover.

In some implementations of the UE described herein, the processor of the UE is configured to: trigger to execute a handover from the serving cell; and in response to triggering the handover, continue performing the prediction operation related to the ping-pong handover towards at least one candidate cell or the short of stay at the at least one candidate cell after the handover.

In some implementations of the UE described herein, the processor of the UE is configured to: in response to predicting that the ping-pong handover will occur in the at least one candidate cell, transmit, to the at least one candidate cell, first information indicating that the ping-pong handover is predicted to occur; or in response to predicting that the short of stay will occur at the at least one candidate cell, transmit, to the at least one candidate cell, second information indicating that the short of stay is predicted to occur after the UE switches to the at least one candidate cell.

In some implementations of the UE described herein, at least one of the first information or the second information is transmitted to the at least one candidate cell via an RRC reconfiguration complete message.

In some implementations of the UE described herein, in response to predicting that the short of stay will occur at the at least one candidate cell, the processor of the UE is configured to transmit at least one of the following to the at least one candidate cell: information regarding another candidate cell, wherein the UE is predicted to switch towards the another candidate cell after staying at the at least one candidate cell; or time duration, wherein the UE is predicted to stay at the at least one candidate cell during the time duration after the UE switches from the serving cell to the at least one candidate cell and before the UE switches from the at least one candidate cell to the another candidate cell.

In some implementations of the UE described herein, each of the at least one candidate cell, the candidate cell, or the first candidate cell is a candidate primary cell (PCell) or a candidate primary secondary cell group cell (PSCell) .

In some implementations of the UE described herein, the prediction operation is performed by an artificial intelligence (AI) entity of the UE.

Some implementations of the present disclosure provide a processor for wireless communication, comprising at least one controller coupled with at least one memory and configured to cause the processor to: receive, from a serving cell of a user equipment (UE) , configuration information used for the UE to predict at least one of the following: a radio link failure (RLF) ; a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and perform a prediction operation based on the configuration information.

Some implementations of the present disclosure provide a method performed by a user equipment (UE) . The method includes: receiving, from a serving cell of the UE, configuration information used for the UE to predict at least one of the following: a radio link failure (RLF) ; a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and performing a prediction operation based on the configuration information.

Some implementations of the present disclosure provide a serving base station (BS) . The serving BS includes at least one memory; and at least one processor coupled to the at least one memory and configured to cause the serving BS to: receive, from a user equipment (UE) , capability regarding whether to support a prediction operation related to at least one of the following: a radio link failure (RLF) ; a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and transmit, to the UE, configuration information regarding the prediction operation.

In some implementations of the serving BS described herein, the processor of the serving BS is configured to transmit, to the UE, a configuration regarding a threshold of a channel quality of a serving cell of the UE to trigger the UE to perform the prediction operation.

In some implementations of the serving BS described herein, the processor of the serving BS is configured to transmit at least one of the following to the UE: a first configuration regarding first time duration used to predict whether the RLF will occur; a second configuration regarding second time duration used to predict whether the ping-pong handover towards a candidate cell will occur; a configuration regarding a first threshold used to predict whether the ping-pong handover will occur; or a configuration regarding a second threshold used to predict whether the short of stay after the handover will occur.

In some implementations of the serving BS described herein, the first configuration includes information of a first timer related to the first time duration, wherein start time of the first timer is a time point of receiving the first configuration or an absolute time point, and wherein the prediction operation related to the RLF is started to be performed at the start time of the first timer and is stopped to be performed upon an expiry of the first timer.

In some implementations of the serving BS described herein, the second configuration includes information of a second timer related to the second time duration, wherein start time of the second timer is a time point of receiving the second configuration or an absolute time point, and wherein the prediction operation related to the ping-pong handover is started to be performed at the start time of the second timer and is stopped to be performed upon an expiry of the second timer.

In some implementations of the serving BS described herein, in response to the UE predicting that the RLF will occur in a serving cell of the UE, the processor of the serving BS is configured to receive, from the UE, a prediction report including at least one of the following: information indicating that the RLF is predicted to occur in the serving cell; a time point at or after which the RLF is predicted to occur in the serving cell; a time window within which the RLF is predicted to occur in the serving cell; or a predicted failure cause of the RLF in the serving cell.

In some implementations of the serving BS described herein, in response to the UE predicting that the ping-pong handover will occur, the processor of the serving BS is configured to receive, from the UE, a prediction report including at least one of the following: information indicating that the ping-pong handover is predicted to occur if the UE switches to a candidate cell; or a time window, wherein the UE is predicted to switch from the candidate cell back to the serving cell if the UE switches from the serving cell to the candidate cell within the time window.

In some implementations of the serving BS described herein, in response to the UE predicting that the short of stay after the handover will occur, the processor of the serving BS is configured to receive, from the UE, a prediction report including at least one of the following: information indicating that the short of stay after the handover is predicted to occur if the UE switches to a candidate cell; a candidate cell list, wherein the candidate cell list includes a first candidate cell, and the short of stay is predicted to occur at the first candidate cell after the UE switches to the first candidate cell; or a time duration list, wherein the time duration list includes third time duration, and the UE is predicted to stay at the first candidate cell during the third time duration after the UE switches from the serving cell to the first candidate cell and before the UE switches from the first candidate cell to another candidate cell.

In some implementations of the serving BS described herein, in response to the UE triggering to execute a handover from a serving cell of the UE towards a candidate cell of a candidate BS and in response to the UE predicting that the ping-pong handover will occur towards the candidate cell, the processor of the serving BS is configured to receive, from the candidate BS, first information indicating that the ping-pong handover is predicted to occur if the UE switches to the candidate cell of the candidate BS.

In some implementations of the serving BS described herein, the first information is received from the candidate BS together with or within a release indication message.

In some implementations of the serving BS described herein, the processor of the serving BS is configured to perform at least one of the following: keeping a context of the UE after the UE switches from the serving cell to the candidate cell of the candidate BS; or transmitting a radio resource control (RRC) reconfiguration message for handover to the candidate BS.

In some implementations of the serving BS described herein, each of the at least one candidate cell, the candidate cell, or the first candidate cell is a candidate primary cell (PCell) or a candidate primary secondary cell group cell (PSCell) .

In some implementations of the serving BS described herein, the prediction operation is performed by an artificial intelligence (AI) entity of the UE.

Some implementations of the present disclosure provide a processor for wireless communication, comprising at least one controller coupled with at least one memory and configured to cause the processor to: at least one controller coupled with at least one memory and configured to cause the processor to: receive, from a user equipment (UE) , capability regarding whether to support a prediction operation related to at least one of the following: a radio link failure (RLF) ; a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and transmit, to the UE, configuration information regarding the prediction operation.

Some implementations of the present disclosure provide a method performed by a serving base station (BS) . The method includes: receiving, from a user equipment (UE) , capability regarding whether to support a prediction operation related to at least one of the following: a radio link failure (RLF) ; a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and transmitting, to the UE, configuration information regarding the prediction operation.

Some implementations of the present disclosure provide a candidate base station (BS) . The candidate BS includes at least one memory; and at least one processor coupled to the at least one memory and configured to cause the candidate BS to: receive, from a serving BS of a user equipment (UE) , a request for handover towards a candidate cell of the candidate BS;transmit, to the serving BS, an acknowledge message related to the candidate cell in response to receipt of the request for handover; and receive, from the UE, a prediction report related to at least one of the following: a radio link failure (RLF) in the candidate cell; a ping-pong handover towards the candidate cell; or a short of stay at the candidate cell after a handover towards the candidate cell.

In some implementations of the candidate BS described herein, the processor of the candidate BS is configured to transmit a radio resource control (RRC) reconfiguration message for the UE, and wherein the RRC reconfiguration message includes a configuration used for the UE to predict whether the RLF will occur.

In some implementations of the candidate BS described herein, in response to the UE predicting that the RLF will occur in the candidate cell, the processor of the candidate BS is configured to receive, from the UE, information indicating that the RLF is predicted to occur in the candidate cell.

In some implementations of the candidate BS described herein, the information is received from the UE via an RRC reconfiguration complete message.

In some implementations of the candidate BS described herein, in response to the UE triggering to execute a handover from a serving cell towards the candidate cell and in response to the UE predicting that the ping-pong handover towards the candidate cell will occur, the prediction report includes information indicating that the ping-pong handover is predicted to occur at the candidate cell if the UE switches to the candidate cell.

In some implementations of the candidate BS described herein, the processor of the candidate BS is configured to transmit the prediction report related to the ping-pong handover to the serving BS.

In some implementations of the candidate BS described herein, the prediction report is transmitted to the serving BS together with or within a release indication message.

In some implementations of the candidate BS described herein, in response to the UE triggering to execute a handover from a serving cell towards the candidate cell and in response to the UE predicting that the short of stay at the candidate cell after the handover will occur, the prediction report includes at least one of the following: information indicating that the short of stay after the handover is predicted to occur if the UE switches to the candidate cell; information regarding another candidate cell, wherein the UE is predicted to switch towards the another candidate cell after staying at the candidate cell; or time duration, wherein the UE is predicted to stay at the candidate cell during the time duration after the UE switches from the serving cell to the candidate cell and before the UE switches from the candidate cell to the another candidate cell.

In some implementations of the candidate BS described herein, the prediction report related to the short of stay is received from the UE together with or within an RRC reconfiguration complete message.

In some implementations of the candidate BS described herein, the candidate cell or the first candidate cell is a candidate primary cell (PCell) or a candidate primary secondary cell group cell (PSCell) .

In some implementations of the candidate BS described herein, the prediction operation is performed by an artificial intelligence (AI) entity of the UE.

Some implementations of the present disclosure provide a processor for wireless communication, comprising at least one controller coupled with at least one memory and configured to cause the processor to: receive, from a serving base station (BS) of a user equipment (UE) , a request for handover towards a candidate cell of a candidate BS; transmit, to the serving BS, an acknowledge message related to the candidate cell in response to receipt of the request for handover; and receive, from the UE, a prediction report related to at least one of the following: a radio link failure (RLF) in the candidate cell; a ping-pong handover towards the candidate cell; or a short of stay at the candidate cell after a handover towards the candidate cell.

Some implementations of the present disclosure provide a method performed by a candidate base station (BS) . The method includes: receiving, from a serving BS of a user equipment (UE) , a request for handover towards a candidate cell of the candidate BS; transmitting, to the serving BS, an acknowledge message related to the candidate cell in response to receipt of the request for handover; and receiving, from the UE, a prediction report related to at least one of the following: a radio link failure (RLF) in the candidate cell; a ping-pong handover towards the candidate cell; or a short of stay at the candidate cell after a handover towards the candidate cell.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates an example of a wireless communications system in accordance with aspects of the present disclosure.

Figure 2 illustrates an example of a user equipment (UE) 200 in accordance with aspects of the present disclosure.

Figure 3 illustrates an example of a processor 300 in accordance with aspects of the present disclosure.

Figure 4 illustrates an example of a network equipment (NE) 400 in accordance with aspects of the present disclosure.

Figure 5 illustrates an exemplary flowchart of an inter-BS handover procedure in accordance with aspects of the present disclosure.

Figures 6-8 illustrate flowcharts of methods related to a prediction operation in accordance with aspects of the present disclosure.

Figures 9-11 illustrate schematic diagrams of a prediction operation in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In general, a cell level mobility requires explicit RRC signalling to be triggered, i.e. a handover, which may also be named as layer 3 (L3) handover for PCell change. For an inter-BS handover, the signalling procedures is illustrated in Figure 5 as described below.

In some cases, in an RRC_CONNECTED state, a UE may perform a Radio Link Monitoring (RLM) in the active bandwidth part (BWP) based on reference signals (e.g. synchronization signal block (SSB) or channel state information reference signal (CSI-RS) ) and signal quality thresholds configured by the network. SSB-based RLM is based on the SSB associated to the initial downlink (DL) BWP and can be configured for the initial DL BWP and for DL BWPs containing the SSB associated to the initial DL BWP. Besides, SSB-based RLM can be also performed based on the non-cell defining SSB, if configured for RedCap UEs. For other DL BWPs, RLM can only be performed based on CSI-RS. In case of a dual active protocol stack (DAPS) handover, the UE continues the detection of a radio link failure at the source cell until the successful completion of the random access procedure to the target cell. For example, the UE may declare a Radio Link Failure (RLF) when one of the following criteria are met:

- expiry of a radio problem timer started after indication of radio problems from the physical layer (if radio problems are recovered before the timer is expired, the UE stops the timer) ; or

- expiry of a timer started upon triggering a measurement report for a measurement identity for which the timer has been configured while another radio problem timer is running; or

- a random access procedure failure; or

- a radio link control (RLC) failure; or

- a detection of consistent uplink listen-before-talk (LBT) failures for operation with shared spectrum channel access; or

- for Integrated Access and Backhaul-Mobile Termination (IAB-MT) , the reception of a backhaul (BH) RLF indication received from its parent node.

Artificial Intelligence (AI) /Machine Learning (ML) is used to learn and perform certain tasks by training the AI/ML models such as neural networks (NNs) with vast amounts of data, which is successfully applied in computer vison (CV) and nature language processing (NLP) areas. Deep learning (DL) , which is a subordinate concept of ML, utilizes multi-layered NNs as an “AI model” to learn how to solve problems and/or optimize performance from vast amounts of data. An AI model may also be named as an AIML model, an AI/ML model, or the like.

Currently, details regarding methods and apparatuses for a prediction operation related to a failure (e.g. an RLF) or a handover have not been discussed in 3GPP technology yet. For example, the prediction operation may be performed by an artificial intelligence (AI) entity of a UE. For example, the following issues need to be solved: what configuration information should be provided to a UE for predication related to an RLF, a ping-pong handover and/or a short of stay after a handover; what prediction information related to an RLF, a ping-pong handover and/or a short of stay after a handover can be reported by a UE; when a UE receives a handover command, whether does the UE stop prediction related to an RLF, a ping-pong handover and a short of stay after a handover; when a UE is performing a handover (e.g. timer T304 is running) , how the UE predicts a ping-pong handover or a short of stay after a handover related to the same candidate cell; and whether or when to report the related information to a candidate cell.

Embodiments of the present disclosure aim to resolve the abovementioned issues. For example, some embodiments design some configurations to provide to a UE for predication related to an RLF, a ping-pong handover and/or a short of stay after a handover. Some embodiments design prediction information related to an RLF, a ping-pong handover and/or a short of stay after a handover reported after a handover performed by a UE. In some embodiments, when a UE receives a handover command, the UE is proposed to stop the prediction related to an RLF. In some other embodiments, regarding the prediction for a ping-pong handover and a short of stay after a handover, a UE may continue the prediction. In some embodiments, when a UE is performing a handover (e.g. timer T304 is running) , the UE may predict a ping-pong handover and/or a short of stay after a handover related to the same candidate cell. The UE is expected to report prediction information to a target cell in time.

In the embodiments of the present disclosure, a UE may predict an RLF in a serving cell, and/or may predict an RLF in a candidate cell, i.e. the UE has capability of supporting a prediction operation related to an RLF in a serving cell and/or a candidate cell.

In the embodiments of the present disclosure, a ping-pong handover refers to a case that, after a UE switches from a source cell to a candidate cell, the UE switches from the candidate cell back to the source cell again, e.g. within a short period. A short of stay after a handover refers to a case that, after a UE switches from the source cell to a candidate cell, the UE stays at this candidate cell for a short period and then switches from this candidate cell to another candidate cell.

In the embodiments of the present disclosure, a prediction operation performed by an AI entity of a UE may also be named as an AI based prediction operation, an AIML model based prediction operation, an AIML model based prediction operation, an AI/ML model based prediction operation, or the like. A prediction report may also be named as a report for prediction, prediction information, a prediction result, information predicted by a UE, information related to a prediction operation of a UE, or the like.

A prediction operation related to an RLF may be named as "an RLF prediction" or the like. A prediction operation related to a ping-pong handover may be named as "a ping-pong handover prediction" or the like. A prediction operation related to a short of stay after a handover may be named as "a prediction for short of stay after handover" or "a short of stay after handover prediction" or the like.

More details of the embodiments of the present disclosure will be illustrated in the following text in combination with the appended drawings.

Figure 1 illustrates an example of a wireless communications system 100 in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more NE 102, one or more UE 104, and a core network (CN) 106. The wireless communications system 100 may support various radio access technologies. In some implementations, the wireless communications system 100 may be a 4G network, such as an LTE network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communications system 100 may be a NR network, such as a 5G network, a 5G-Advanced (5G-A) network, or a 5G ultrawideband (5G-UWB) network. In other implementations, the wireless communications system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20. The wireless communications system 100 may support radio access technologies beyond 5G, for example, 6G. Additionally, the wireless communications system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The one or more NE 102 may be dispersed throughout a geographic region to form the wireless communications system 100. One or more of the NE 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a network function, a network entity, a radio access network (RAN) , a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. An NE 102 and a UE 104 may communicate via a communication link, which may be a wireless or wired connection. For example, an NE 102 and a UE 104 may perform wireless communication (e.g. receive signaling, transmit signaling) over a Uu interface.

An NE 102 may provide a geographic coverage area for which the NE 102 may support services for one or more UEs 104 within the geographic coverage area. For example, an NE 102 and a UE 104 may support wireless communication of signals related to services (e.g. voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, an NE 102 may be moveable, for example, a satellite associated with a non-terrestrial network (NTN) . In some implementations, different geographic coverage areas associated with the same or different radio access technologies may overlap, but the different geographic coverage areas may be associated with different NE 102.

The one or more UE 104 may be dispersed throughout a geographic region of the wireless communications system 100. A UE 104 may include or may be referred to as a remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples.

A UE 104 may be able to support wireless communication directly with other UEs 104 over a communication link. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

An NE 102 may support communications with the CN 106, or with another NE 102, or both. For example, an NE 102 may interface with other NE 102 or the CN 106 through one or more backhaul links (e.g. S1, N2, or network interface) . In some implementations, the NE 102 may communicate with each other directly. In some other implementations, the NE 102 may communicate with each other or indirectly (e.g. via the CN 106. In some implementations, one or more NE 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as a radio heads, smart radio heads, or transmission-reception points (TRPs) .

The CN 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g. a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g. a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g. data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more NE 102 associated with the CN 106.

The CN 106 may communicate with a packet data network over one or more backhaul links (e.g. via an S1, N2, or another network interface) . The packet data network may include an application server. In some implementations, one or more UEs 104 may communicate with the application server. A UE 104 may establish a session (e.g. a protocol data unit (PDU) session, or the like) with the CN 106 via an NE 102. The CN 106 may route traffic (e.g. control information, data, and the like) between the UE 104 and the application server using the established session (e.g. the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the CN 106 (e.g. one or more network functions of the CN 106) .

In the wireless communications system 100, the NEs 102 and the UEs 104 may use resources of the wireless communications system 100 (e.g. time resources (e.g. symbols, slots, subframes, frames, or the like) or frequency resources (e.g. subcarriers, carriers) ) to perform various operations (e.g. wireless communications) . In some implementations, the NEs 102 and the UEs 104 may support different resource structures. For example, the NEs 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the NEs 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the NEs 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The NEs 102 and the UEs 104 may support various frame structures based on one or more numerologies.

One or more numerologies may be supported in the wireless communications system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g. μ=0) may be associated with a first subcarrier spacing (e.g. 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g. μ=0) associated with the first subcarrier spacing (e.g. 15 kHz) may utilize one slot per subframe. A second numerology (e.g. μ=1) may be associated with a second subcarrier spacing (e.g. 30 kHz) and a normal cyclic prefix. A third numerology (e.g. μ=2) may be associated with a third subcarrier spacing (e.g. 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g. μ=3) may be associated with a fourth subcarrier spacing (e.g. 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g. μ=4) may be associated with a fifth subcarrier spacing (e.g. 240 kHz) and a normal cyclic prefix.

A time interval of a resource (e.g. a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g. a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g. quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communications system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g. quantity) of symbols (e.g. OFDM symbols) . In some implementations, the number (e.g. quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g. applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g. μ=0) associated with a first subcarrier spacing (e.g. 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communications system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communications system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the NEs 102 and the UEs 104 may perform wireless communications over one or more of the operating frequency bands. In some implementations, FR1 may be used by the NEs 102 and the UEs 104, among other equipment or devices for cellular communications traffic (e.g. control information, data) . In some implementations, FR2 may be used by the NEs 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g. at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g. μ=0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g. μ=1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g. μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g. at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g. μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g. μ=3) , which includes 120 kHz subcarrier spacing.

Figure 2 illustrates an example of a UE 200 in accordance with aspects of the present disclosure. The UE 200 may include a processor 202, a memory 204, a controller 206, and a transceiver 208. The processor 202, the memory 204, the controller 206, or the transceiver 208, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g. operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 202, the memory 204, the controller 206, or the transceiver 208, or various combinations or components thereof may be implemented in hardware (e.g. circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

The processor 202 may include an intelligent hardware device (e.g. a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 202 may be configured to operate the memory 204. In some other implementations, the memory 204 may be integrated into the processor 202. The processor 202 may be configured to execute computer-readable instructions stored in the memory 204 to cause the UE 200 to perform various functions of the present disclosure.

The memory 204 may include volatile or non-volatile memory. The memory 204 may store computer-readable, computer-executable code including instructions when executed by the processor 202 cause the UE 200 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such the memory 204 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 202 and the memory 204 coupled with the processor 202 may be configured to cause the UE 200 to perform one or more of the functions described herein (e.g. executing, by the processor 202, instructions stored in the memory 204) . For example, the processor 202 may support wireless communication at the UE 200 in accordance with examples as disclosed with respect to Figure 6. The UE 200 may be configured to support: a means for receiving, from a serving cell of UE 200, configuration information used for UE 200 to predict at least one of the following: an RLF; a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and a means for performing a prediction operation based on the configuration information.

The controller 206 may manage input and output signals for the UE 200. The controller 206 may also manage peripherals not integrated into the UE 200. In some implementations, the controller 206 may utilize an operating system such as or other operating systems. In some implementations, the controller 206 may be implemented as part of the processor 202.

In some implementations, the UE 200 may include at least one transceiver 208. In some other implementations, the UE 200 may have more than one transceiver 208. The transceiver 208 may represent a wireless transceiver. The transceiver 208 may include one or more receiver chains 210, one or more transmitter chains 212, or a combination thereof. The means for receiving abovementioned in the processor 202 or the means for transmitting in the processor 202 may be implemented via at least one transceiver 208.

A receiver chain 210 may be configured to receive signals (e.g. control information, data, packets) over a wireless medium. For example, the receiver chain 210 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 210 may include at least one amplifier (e.g. a low-noise amplifier (LNA) ) configured to amplify the received signal. The receiver chain 210 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 210 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

A transmitter chain 212 may be configured to generate and transmit signals (e.g. control information, data, packets) . The transmitter chain 212 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmitter chain 212 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 212 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

Figure 3 illustrates an example of a processor 300 in accordance with aspects of the present disclosure. The processor 300 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 300 may include a controller 302 configured to perform various operations in accordance with examples as described herein. The processor 300 may optionally include at least one memory 304, which may be, for example, an L1/L2/L3 cache. Additionally, or alternatively, the processor 300 may optionally include one or more arithmetic-logic units (ALUs) 306. One or more of these components may be in electronic communication or otherwise coupled (e.g. operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g. buses) .

The processor 300 may be a processor chipset and include a protocol stack (e.g. a software stack) executed by the processor chipset to perform various operations (e.g. receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g. memory local to or included in the processor chipset (e.g. the processor 300) or other memory (e.g. random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 302 may be configured to manage and coordinate various operations (e.g. signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 300 to cause the processor 300 to support various operations in accordance with examples as described herein. For example, the controller 302 may operate as a control unit of the processor 300, generating control signals that manage the operation of various components of the processor 300. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 302 may be configured to fetch (e.g. obtain, retrieve, receive) instructions from the memory 304 and determine subsequent instruction (s) to be executed to cause the processor 300 to support various operations in accordance with examples as described herein. The controller 302 may be configured to track memory address of instructions associated with the memory 304. The controller 302 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 302 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 300 to cause the processor 300 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 302 may be configured to manage flow of data within the processor 300. The controller 302 may be configured to control transfer of data between registers, arithmetic logic units (ALUs) , and other functional units of the processor 300.

The memory 304 may include one or more caches (e.g. memory local to or included in the processor 300 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 304 may reside within or on a processor chipset (e.g. local to the processor 300) . In some other implementations, the memory 304 may reside external to the processor chipset (e.g. remote to the processor 300) .

The memory 304 may store computer-readable, computer-executable code including instructions that, when executed by the processor 300, cause the processor 300 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 302 and/or the processor 300 may be configured to execute computer-readable instructions stored in the memory 304 to cause the processor 300 to perform various functions. For example, the processor 300 and/or the controller 302 may be coupled with or to the memory 304, the processor 300, the controller 302, and the memory 304 may be configured to perform various functions described herein. In some examples, the processor 300 may include multiple processors and the memory 304 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 306 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 306 may reside within or on a processor chipset (e.g. the processor 300) . In some other implementations, the one or more ALUs 306 may reside external to the processor chipset (e.g. the processor 300) . One or more ALUs 306 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 306 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 306 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 306 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 306 to handle conditional operations, comparisons, and bitwise operations.

The processor 300 may support wireless communication in accordance with examples as disclosed herein.

In some implementations, the processor 300 may be configured to support a means for performing operations of a UE as described with respect to Figure 6. The processor 300 may be configured to or operable to support: a means for receiving, from a serving cell of UE 200, configuration information used for UE 200 to predict at least one of the following: an RLF; a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and a means for performing a prediction operation based on the configuration information.

In some implementations, the processor 300 may be configured to support a means for performing operations of a serving BS as described with respect to Figure 7. The processor 300 may be configured to or operable to support: a means for receiving, from a UE, capability regarding whether to support a prediction operation related to at least one of the following: an RLF; a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and a means for transmitting, to the UE, configuration information regarding the prediction operation.

In some implementations, the processor 300 may be configured to support a means for performing operations of a candidate BS as described with respect to Figure 8. For example, the processor 300 may be configured to or operable to support: a means for receiving, from a serving BS of a user equipment (UE) , a request for handover towards a candidate cell of the candidate BS; a means for transmitting, to the serving BS, an acknowledge message related to the candidate cell in response to receipt of the request for handover; and a means for receiving, from the UE, a prediction report related to at least one of the following: a radio link failure (RLF) in the candidate cell; a ping-pong handover towards the candidate cell; or a short of stay at the candidate cell after a handover towards the candidate cell.

It should be appreciated by persons skilled in the art that the components in exemplary processor 300 may be changed, for example, some of the components in exemplary processor 300 may be omitted or modified or new component (s) may be added to exemplary processor 300, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the processor 300 may not include the ALUs 306.

Figure 4 illustrates an example of a NE 400 in accordance with aspects of the present disclosure. The NE 400 may include a processor 402, a memory 404, a controller 406, and a transceiver 408. The processor 402, the memory 404, the controller 406, or the transceiver 408, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g. operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 402, the memory 404, the controller 406, or the transceiver 408, or various combinations or components thereof may be implemented in hardware (e.g. circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

The processor 402 may include an intelligent hardware device (e.g. a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 402 may be configured to operate the memory 404. In some other implementations, the memory 404 may be integrated into the processor 402. The processor 402 may be configured to execute computer-readable instructions stored in the memory 404 to cause the NE 400 to perform various functions of the present disclosure.

The memory 404 may include volatile or non-volatile memory. The memory 404 may store computer-readable, computer-executable code including instructions when executed by the processor 402 cause the NE 400 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such the memory 404 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 402 and the memory 404 coupled with the processor 402 may be configured to cause the NE 400 to perform one or more of the functions described herein (e.g. executing, by the processor 402, instructions stored in the memory 404) . For example, the processor 402 may support wireless communication at the NE 400 in accordance with examples as disclosed herein. For example, the NE 400 may be configured to support a means for performing the operations as described with respect to Figures 7 and 8 as described below.

In some implementations, the NE 400 may be a serving BS as described with respect to Figure 7. The NE 400 may be configured to support: a means for receiving, from a UE, capability regarding whether to support a prediction operation related to at least one of the following: an RLF; a ping-pong handover towards at least one candidate cell; or a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and a means for transmitting, to the UE, configuration information regarding the prediction operation.

In some implementations, the NE 400 may be a candidate BS as described with respect to Figure 8. The NE 400 may be configured to support: a means for receiving, from a serving BS of a user equipment (UE) , a request for handover towards a candidate cell of the candidate BS; a means for transmitting, to the serving BS, an acknowledge message related to the candidate cell in response to receipt of the request for handover; and a means for receiving, from the UE, a prediction report related to at least one of the following: a radio link failure (RLF) in the candidate cell; a ping-pong handover towards the candidate cell; or a short of stay at the candidate cell after a handover towards the candidate cell.

The controller 406 may manage input and output signals for the NE 400. The controller 406 may also manage peripherals not integrated into the NE 400. In some implementations, the controller 406 may utilize an operating system such as or other operating systems. In some implementations, the controller 406 may be implemented as part of the processor 402.

In some implementations, the NE 400 may include at least one transceiver 408. In some other implementations, the NE 400 may have more than one transceiver 408. The transceiver 408 may represent a wireless transceiver. The transceiver 408 may include one or more receiver chains 410, one or more transmitter chains 412, or a combination thereof. The means for receiving or the means for transmitting abovementioned in the processor 402 may be implemented via at least one transceiver 408.

A receiver chain 410 may be configured to receive signals (e.g. control information, data, packets) over a wireless medium. For example, the receiver chain 410 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 410 may include at least one amplifier (e.g. a low-noise amplifier (LNA) ) configured to amplify the received signal. The receiver chain 410 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 410 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

A transmitter chain 412 may be configured to generate and transmit signals (e.g. control information, data, packets) . The transmitter chain 412 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmitter chain 412 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 412 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

It should be appreciated by persons skilled in the art that the components in exemplary NE 400 may be changed, for example, some of the components in exemplary NE 400 may be omitted or modified or new component (s) may be added to exemplary NE 400, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the NE 400 may not include the controller 406.

Figure 5 illustrates an exemplary flowchart of an inter-BS handover procedure in accordance with aspects of the present disclosure. The embodiments of Figure 5 show a procedure of a UE (e.g., UE 510) communicating with two BSs (e.g., source BS 520 and target BS 530) . In some examples, UE 510 may function as UE 104 in Figure 1 or UE 200 in Figure 2. Source BS 520 and/or target BS 530 may function as NE 400 in Figure 4.

Referring to the embodiments of FIG. 5, in operation 501, source BS 520 may transmit a handover request message to target BS 530. For example, the handover request message may pass a transparent RRC container with necessary information to prepare a handover procedure at target BS 530 side.

In operation 502, target BS 530 may perform admission control based on the load of a target cell of target BS 530, to decide whether to allow the handover procedure of UE 510 after receiving the handover request message from source BS 520.

In operation 503, based on an admission control result, target BS 530 may prepare handover resource (s) for UE 510 and send a handover request acknowledge message including an RRC reconfiguration message to source BS 520.

In operation 504, a RAN handover initiation is performed. Source BS 520 may transmit an RRC reconfiguration message to UE 510. The RRC reconfiguration message may include a reconfiguration with synchronization IE, e.g., reconfigurationWithSync IE as specified in 3GPP standard documents. The RRC reconfiguration message may contain information required to access the target cell of target BS 530.

In operation 505, UE 510 may access to the target cell and complete the handover procedure. In operation 506, UE 510 may send an RRC reconfiguration complete message to target BS 530.

Figure 6 illustrates a flowchart of a method related to a prediction operation in accordance with aspects of the present disclosure. The operations of the method may be implemented by a UE as described herein. In some implementations, the UE may execute a set of instructions to control the function elements of the UE to perform the described functions. In some implementations, aspects of operations 602 and 604 may be performed by UE 200 as described with reference to Figure 2. Each of operations 602 and 604 may be performed in accordance with examples as described herein. Specific examples are described in the embodiments of Figures 9-11 as follows.

At operation 602, the method may include receiving, by a UE from a serving cell of the UE, configuration information used for the UE to predict at least one of the following:

(1) an RLF, e.g. an RLF in a serving cell and/or a candidate cell;

(2) a ping-pong handover towards at least one candidate cell; or

(3) a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell.

In some embodiments, the serving cell, the candidate cell, and/or the at least one candidate cell may be a primary cell (PCell) or a primary secondary cell group cell (PSCell) , e.g. the UE accesses the serving cell via a master cell group (MCG) only or via a dual connectivity (DC) .

At operation 604, the method may include performing a prediction operation by the UE based on the configuration information received at operation 602. In some embodiments, the prediction operation is performed by an artificial intelligence (AI) entity of the UE. The prediction operation may be named as an AI based prediction operation, an AIML model based prediction operation, an AIML model based prediction operation, an AI/ML model based prediction operation, or the like.

In some embodiments of the method, the UE may report, to the serving cell, capability regarding whether to support the prediction operation related to the RLF, the ping-pong handover and/or the short of stay after the handover. A prediction operation related to an RLF may be named as "an RLF prediction" or the like. A prediction operation related to a ping-pong handover may be named as "a ping-pong handover prediction" or the like. A prediction operation related to a short of stay after a handover may be named as "a prediction for short of stay after handover" or "a short of stay after handover prediction" or the like.

In some embodiments of the method, the UE may receive, from the serving cell, a configuration regarding a threshold (denoted as threshold #1) of a channel quality of the serving cell to trigger to perform the prediction operation. In an embodiment, an access stratum (AS) layer of the UE may deliver, to an upper layer of the UE or an AI entity of the UE, information indicating to perform the prediction operation if the channel quality of the serving cell is less than threshold #1. For instance, threshold #1 may be associated with layer 1 (L1) or layer 3 (L3) measurement result.

In some embodiments of the method, an AS layer of the UE may deliver, to an upper layer or an AI entity of the UE, one or more measurement results of the serving cell. Then, the upper layer or the AI entity of the UE may determine whether to start or stop performing the prediction operation based on the one or more measurement results.

In some embodiments of the method, the UE may receive at least one of the following from the serving cell:

(1) A configuration (denoted as configuration #1) regarding time duration (denoted as time duration #1) used to predict whether the RLF will occur.

(2) Another configuration (denoted as configuration #2) regarding another time duration (denoted as time duration #2) used to predict whether the ping-pong handover towards a candidate cell will occur.

(3) A configuration regarding a threshold (denoted as threshold #2) used to predict whether the ping-pong handover will occur. In an implementation, the UE may predict that the ping-pong handover will occur if a time period staying at the at least one candidate cell is less than threshold #2 and then the UE may switch from the at least one candidate cell back to the serving cell.

(4) A configuration regarding another threshold (denoted as threshold #3) used to predict whether the short of stay after the handover will occur. In an implementation, the UE may predict that the short of stay will occur if a time period staying at the at least one candidate cell after the handover is less than threshold #3 and then the UE may switch from the at least one candidate cell to another candidate cell.

In an implementation, configuration #1 includes information of a timer (denoted as timer #1) related to time duration #1. Start time of timer #1 may be a time point of the UE receiving configuration #1 or an absolute time point (e.g. coordinated universal time (UTC) time) . The UE may start performing the prediction operation related to the RLF at the start time of timer #1, and may stop performing the prediction operation related to the RLF upon an expiry of timer #1.

In another implementation, configuration #2 includes information of a timer (denoted as timer #2) related to time duration #2. Start time of timer #2 may be a time point of receiving configuration #2 or an absolute time point (e.g. UTC time) . The UE may start performing the prediction operation related to the ping-pong handover at the start time of timer #2, and may stop performing the prediction operation related to the ping-pong handover upon an expiry of timer #2.

In some embodiments of the method, if the UE predicts that at least one of the RLF, the ping-pong handover, or the short of stay after the handover will occur, the UE may transmit a prediction report to the serving cell.

In an embodiment, if the UE predicts that the RLF will occur in the serving cell, the prediction report may include at least one of the following:

(1) information indicating that the RLF is predicted to occur in the serving cell;

(2) a time point at which the RLF is predicted to occur in the serving cell;

(3) a time point after which the RLF is predicted to occur in the serving cell;

(4) a time window within which the RLF is predicted to occur in the serving cell; or

(5) a predicted failure cause of the RLF in the serving cell, e.g. the UE predicts that the RLF that will occur in the serving cell is due to at least one of the following failure causes:

a) timer T310 expiry;

b) timer T312 expiry;

c) upon receipt of a random access problem indication from MCG;

d) the maximum number of RLC retransmissions has been reached;

e) if connected as an IAB-node, upon BH RLF indication received; or

f) upon receipt of consistent uplink listen before talk (LBT) failure indication.

In another embodiment, if the UE predicts that the ping-pong handover will occur, the prediction report may include at least one of the following:

(1) Information indicating that the ping-pong handover is predicted to occur if the UE switches to a candidate cell. For example, the information includes a candidate cell list, and the ping-pong handover is predicted to occur at a candidate cell within the candidate cell list if the UE switches to the candidate cell.

(2) A time window. In some implementations, if the UE switches from the serving cell to the candidate cell, the UE is predicted to switch from the candidate cell back to the serving cell within the time window. In some other implementations, if the UE switches from the serving cell to the candidate cell within the time window, the UE is predicted to switch from the candidate cell back to the serving cell.

In an additional embodiment, if the UE predicts that the short of stay after the handover will occur, the prediction report may include at least one of the following:

(1) Information indicating that the short of stay after the handover is predicted to occur if the UE switches to a candidate cell.

(2) A candidate cell list (denoted as candidate cell list #1) . For example, the short of stay is predicted to occur at a candidate cell within candidate cell list #1 after the UE switches to the candidate cell.

(3) A time duration list (denoted as time duration list #1) . For example, time duration list #1 is a set of accurate time duration for each cell in candidate cell list #1. In some implementations, time duration list #1 includes time duration (e.g. time duration #a) , and the UE is predicted to stay at a candidate cell (e.g. candidate cell #1) during time duration #a after the UE switches from the serving cell to candidate cell #1 and before the UE switches from candidate cell #1 to another candidate cell (e.g. candidate cell #2) . A specific example is described in the embodiments of Figure 9 as follows.

In some embodiments of the method, the UE may trigger to execute a handover from the serving cell, e.g. upon reception of a handover command or at least one conditional handover (CHO) condition is met. In response to triggering the handover, the UE may stop performing the prediction operation related to the RLF for the serving cell.

In some implementations, an AS layer of the UE may deliver, to an upper layer or an AI entity of the UE, information indicating to stop performing the prediction operation (e.g. related to the RLF for the serving cell) in response to triggering the handover. In some implementations, to stop the prediction operation, the UE may stop a timer (e.g. timer #1 as described above) used to predict whether the RLF (e.g. for the serving cell) will occur if the timer is running.

In some embodiments of the method, the UE may receive an RRC reconfiguration message from a candidate cell. If the RRC reconfiguration message includes a configuration used to predict whether the RLF will occur, the UE may start performing the prediction operation related to the RLF for the candidate cell after the UE switches to the candidate cell. In an example, after the UE handovers to target cell #1, the UE may start to predict whether an RLF will occur in target cell #1.

In some implementations, if the UE predicts that the RLF will occur in the candidate cell (e.g. target cell #1) , the UE may transmit, to the candidate cell, information indicating that the RLF is predicted to occur in the candidate cell. In an implementation, the information is transmitted to the candidate cell via an RRC reconfiguration complete message or a handover complete message.

For instance, the UE may transmit, to the candidate cell (e.g. target cell #1) , a prediction report which includes at least one of the following:

(1) information indicating that the RLF is predicted to occur in the candidate cell;

(2) a time point at or after which the RLF is predicted to occur in the candidate cell;

(3) a time window within which the RLF is predicted to occur in the candidate cell; or

(4) a predicted failure cause of the RLF in the candidate cell, e.g., including at least one of the following failure causes:

a) timer T310 expiry;

b) timer T312 expiry;

c) upon receipt of a random access problem indication from MCG;

d) the maximum number of RLC retransmissions has been reached;

e) if connected as an IAB-node, upon BH RLF indication received; or

f) upon receipt of consistent uplink LBT failure indication. A specific example is described in the embodiments of Figure 10 as follows.

In some embodiments of the method, the UE may trigger to execute a handover from the serving cell. In response to triggering the handover, the UE may stop performing the prediction operation related to the ping-pong handover towards at least one candidate cell or the short of stay at the at least one candidate cell after the handover. In some implementations, an AS layer of the UE may deliver, to an upper layer or an AI entity of the UE, information indicating to stop performing the prediction operation in response to triggering the handover.

In some embodiments of the method, the UE may trigger to execute a handover from the serving cell, and in response to triggering the handover, the UE may continue performing the prediction operation related to the ping-pong handover towards at least one candidate cell or the short of stay at the at least one candidate cell after the handover.

In an embodiment, in response to triggering the handover, if the UE predicts that the ping-pong handover will occur in the at least one candidate cell (e.g. candidate cell #m) , the UE may transmit, to the at least one candidate cell, information (denoted as information #1) indicating that the ping-pong handover is predicted to occur.

In another embodiment, in response to triggering the handover, if the UE predicts that the short of stay will occur at the at least one candidate cell, the UE may transmit, to the at least one candidate cell, information (denoted as information #2) indicating that the short of stay is predicted to occur after the UE switches to the at least one candidate cell.

For example, information #1 and/or information #2 may be transmitted to the at least one candidate cell via an RRC reconfiguration complete message.

In some implementations, if the UE predicts that the short of stay will occur at the at least one candidate cell (e.g. candidate cell #a) , in response to triggering the handover, the UE may transmit at least one of the following to candidate cell #a:

(1) Information regarding another candidate cell (e.g. candidate cell #b) . For instance, the UE is predicted to switch from candidate cell #a towards candidate cell #b, after staying at candidate cell #a in a short period.

(2) Time duration. For instance, the UE is predicted to stay at candidate cell #a during the time duration after the UE switches from the serving cell to candidate cell #a and before the UE switches from candidate cell #a to another candidate cell (e.g. candidate cell #b) . A specific example is described in the embodiments of Figure 11 as follows.

It should be noted that the method described in Figure 6 describes possible implementations, and that the operations and the steps may be rearranged or otherwise eliminated or modified and that other implementations are possible, without departing from the spirit and scope of the disclosure.

Figure 7 illustrates a flowchart of a method related to a prediction operation in accordance with aspects of the present disclosure. The operations of the method may be implemented by a network node, e.g. a serving BS as described herein. In some implementations, the serving BS may execute a set of instructions to control the function elements of the serving BS to perform the described functions. In some implementations, aspects of operations 702 and 704 may be performed by NE 400 as described with reference to Figure 4. Each of operations 702 and 704 may be performed in accordance with examples as described herein. Specific examples are described in the embodiments of Figures 9 and 11 as follows.

At operation 702, the method may include receiving, by a serving BS from a UE, capability regarding whether to support a prediction operation related to at least one of the following: (1) an RLF; (2) a ping-pong handover towards at least one candidate cell; or (3) a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell.

In some embodiments, the at least one candidate cell may be a candidate PCell, e.g. the UE accesses the candidate cell via a MCG only. In some other embodiments, the at least one candidate cell may be a candidate PSCell, e.g. the UE accesses the candidate cell via a dual connectivity (DC) .

At operation 704, the method may include transmitting, by the serving BS to the UE, configuration information regarding the prediction operation. In some embodiments, the prediction operation is performed by an AI entity of the UE. The prediction operation may be named as an AI based prediction operation, an AIML model based prediction operation, an AIML model based prediction operation, an AI/ML model based prediction operation, or the like.

In some embodiments of the method, the serving BS may transmit, to the UE, a configuration regarding a threshold (e.g. threshold #1 as described in the embodiments of Figure 6) of a channel quality of a serving cell of the UE to trigger the UE to perform the prediction operation. For instance, the threshold may be associated with layer 1 (L1) or layer 3 (L3) measurement result.

In some embodiments of the method, the serving BS may transmit at least one of the following to the UE:

(1) A configuration (e.g. configuration #1 as described in the embodiments of Figure 6) regarding time duration (e.g. time duration #1 as described in the embodiments of Figure 6) used to predict whether the RLF will occur.

(2) A configuration (e.g. configuration #2 as described in the embodiments of Figure 6) regarding time duration (e.g. time duration #2 as described in the embodiments of Figure 6) used to predict whether the ping-pong handover towards a candidate cell will occur.

(3) A configuration regarding a threshold (e.g. threshold #2 as described in the embodiments of Figure 6) used to predict whether the ping-pong handover will occur. In an implementation, the UE may predict that the ping-pong handover will occur if a time period staying at the at least one candidate cell is less than threshold #2.

(4) A configuration regarding a threshold (e.g. threshold #3 as described in the embodiments of Figure 6) used to predict whether the short of stay after the handover will occur. In an implementation, the UE may predict that the short of stay will occur if a time period staying at the at least one candidate cell after the handover is less than threshold #3. All contents related to the configuration (e.g. configuration #1 and configuration #2) transmitted by the serving BS to the UE described in the embodiments of Figure 6 may be applied here in the embodiments of Figure 7.

In some embodiments of the method, if the UE predicts that the RLF will occur in a serving cell of the UE, the serving BS may receive, from the UE, a prediction report including at least one of the following:

(2) a time point at which the RLF is predicted to occur in the serving cell;

(3) a time point after which the RLF is predicted to occur in the serving cell;

(5) a predicted failure cause of the RLF in the serving cell, e.g. which may include at least one of the following failure causes:

a) timer T310 expiry;

b) timer T312 expiry;

c) upon receipt of a random access problem indication from MCG;

d) the maximum number of RLC retransmissions has been reached;

e) if connected as an IAB-node, upon BH RLF indication received; or

f) upon receipt of consistent uplink LBT failure indication.

In some embodiments of the method, if the UE predicts that that the ping-pong handover will occur, the serving BS may receive, from the UE, a prediction report including at least one of the following:

(1) information indicating that the ping-pong handover is predicted to occur if the UE switches to a candidate cell; or

In some embodiments of the method, if the UE predicts that the short of stay after the handover will occur, the serving BS may receive, from the UE, a prediction report including at least one of the following:

(2) A candidate cell list (e.g. candidate cell list #1 as described in the embodiments of Figure 6) . For example, the short of stay is predicted to occur at a candidate cell within candidate cell list #1 after the UE switches to the candidate cell.

(3) A time duration list. For example, the time duration list is a list of accurate time duration for each cell in candidate cell list #1. In some implementations, the time duration list includes a time duration (e.g. time duration #a) , and the UE is predicted to stay at a candidate cell (e.g. candidate cell #1) during time duration #a after the UE switches from the serving cell to candidate cell #1 and before the UE switches from candidate cell #1 to another candidate cell (e.g. candidate cell #2) . A specific example is described in the embodiments of Figure 9 as follows.

In some embodiments of the method, if the UE triggers to execute a handover from a serving cell of the UE towards a candidate cell (e.g. candidate cell #m) of a candidate BS and if the UE predicts that the ping-pong handover will occur towards the candidate cell, the serving BS may receive, from the candidate BS, information indicating that the ping-pong handover is predicted to occur if the UE switches to the candidate cell of the candidate BS. The information may be received by the candidate BS from the UE and then transferred to the serving BS. In some implementations, the serving BS also receive a release indication message from the candidate BS. In an example, the information is received together with the release indication message, e.g. in separate messages. In another example, the information is received within the release indication message.

In an implementation, after receiving the information from the candidate BS, the serving BS may: keep a context of the UE after the UE switches from the serving cell to the candidate cell of the candidate BS and/or transmit an RRC reconfiguration message for handover to the candidate BS. A specific example is described in the embodiments of Figure 11 as follows.

It should be noted that the method described in Figure 7 describes possible implementations, and that the operations and the steps may be rearranged or otherwise eliminated or modified and that other implementations are possible, without departing from the spirit and scope of the disclosure.

Figure 8 illustrates a flowchart of a method related to an LTM cell switch procedure in accordance with aspects of the present disclosure. The operations of the method may be implemented by a network node, e.g. a candidate BS as described herein. In some implementations, the candidate BS may execute a set of instructions to control the function elements of the candidate BS to perform the described functions. In some implementations, aspects of operations 802, 804 and 806 may be performed by NE 400 as described with reference to Figure 4. Each of operations 802, 804 and 806 may be performed in accordance with examples as described herein. Specific examples are described in the embodiments of Figures 10 and 11 as follows.

At operation 802, the method may include receiving, by a candidate BS from a serving BS of a UE, a request for handover towards a candidate cell (e.g. target cell #1) of the candidate BS, e.g. a handover request message.

At operation 804, the method may include transmitting, by the candidate BS to the serving BS, an acknowledge message related to the candidate cell (e.g. target cell #1) in response to receipt of the request for handover, e.g. a handover request acknowledge message.

At operation 806, the method may include receiving, by the candidate BS from the UE, a prediction report related to at least one of the following: (1) an RLF in the candidate cell (e.g. target cell #1) ; (2) a ping-pong handover towards the candidate cell; or (3) a short of stay at the candidate cell after a handover towards the candidate cell.

In some embodiments, the candidate cell (e.g. target cell #1) may be a candidate PCell, e.g. the UE accesses the candidate cell via a MCG only. In some other embodiments, the candidate cell may be a candidate PSCell, e.g. the UE accesses the candidate cell via a dual connectivity (DC) .

In some embodiments of the method, the candidate BS may transmit an RRC reconfiguration message for the UE, e.g. the RRC reconfiguration message includes a configuration used for the UE to predict whether the RLF will occur.

In some embodiments of the method, if the UE predicts that the RLF will occur in the candidate cell (e.g. target cell #1) , the candidate BS may receive, from the UE, information indicating that the RLF is predicted to occur in the candidate cell. For example, the information is received from the UE via an RRC reconfiguration complete message.

In an embodiment, if the UE predicts that the RLF will occur in the candidate cell (e.g. target cell #1) , the candidate BS may receive, from the UE, a prediction report which includes at least one of the following:

a) timer T310 expiry;

b) timer T312 expiry;

c) upon receipt of a random access problem indication from MCG;

d) the maximum number of RLC retransmissions has been reached;

e) if connected as an IAB-node, upon BH RLF indication received; or

In some embodiments of the method, if the UE triggers to execute a handover from a serving cell towards the candidate cell (e.g. candidate cell #m) and if the UE predicts that the ping-pong handover towards the candidate cell will occur, the prediction report received in operation 806 may include information indicating that the ping-pong handover is predicted to occur at the candidate cell if the UE switches to the candidate cell.

In some implementations, the candidate BS may transfer the received prediction report related to the ping-pong handover to the serving BS. For instance, the candidate BS may also transmit a release indication message to the serving BS. In an implementation, the prediction report is transmitted to the serving BS together with the release indication message (e.g. in separate messages) . In another implementation, the prediction report is transmitted within the release indication message.

In some embodiments of the method, if the UE triggers to execute a handover from a serving cell towards the candidate cell (e.g. candidate cell #a) and if the UE predicts that "the short of stay at the candidate cell after the handover to the candidate cell" will occur, the prediction report received in operation 806 may include at least one of the following:

(1) Information indicating that the short of stay after the handover is predicted to occur if the UE switches to the candidate cell (e.g. candidate cell #a) .

(2) Information regarding another candidate cell (e.g. candidate cell #b) . The UE may predict that it will switch from the candidate cell (e.g. candidate cell #a) towards this another candidate cell (e.g. candidate cell #b) after staying at the candidate cell, e.g. in a short period.

(3) Time duration (e.g. the short period) . The UE may predict that it will stay at the candidate cell (e.g. candidate cell #a) during the time duration after switching from the serving cell to the candidate cell and before switching from the candidate cell to another candidate cell (e.g. candidate cell #b) .

In some embodiments of the method, the candidate BS also receives an RRC reconfiguration complete message from the UE. In an example, the prediction report related to the short of stay is received together with the RRC reconfiguration complete message in operation 806, e.g. in separate messages. In another example, the prediction report related to the short of stay is received within the RRC reconfiguration complete message in operation 806. A specific example is described in the embodiments of Figure 11 as follows.

It should be noted that the method described in Figure 8 describes possible implementations, and that the operations and the steps may be rearranged or otherwise eliminated or modified and that other implementations are possible, without departing from the spirit and scope of the disclosure.

Figure 9 illustrates a schematic diagram of a prediction operation in accordance with aspects of the present disclosure. Details described in all other embodiments of the present disclosure are applicable for the embodiments shown in Figure 9.

In the exemplary flowchart 900 as shown in Figure 9, in operation 901, UE 910 accesses serving BS 920 (e.g. serving gNB) via MCG only or a DC.

In some implementations, UE 910 may be configured with measurement configuration information related to L1 measurement and/or L3 measurement. UE 910 may send an L1 measurement report or an L3 measurement report to serving BS 920, e.g. in operation 901.

In some implementations, UE 910 may report capability including whether to support an RLF prediction, whether to support a ping-pong handover prediction and/or whether to support the prediction for a short of stay at a target cell after a handover.

In operation 902, serving BS 920 transmits configuration information to UE 910.

In some implementations, serving BS 920 configures UE 910 to predict an RLF, a ping-pong handover towards a set of candidate cells, and/or a short of stay after a handover related to a set of candidate cells. Different operations may be performed according to different embodiments, e.g. Option #1 and Option #2 as below.

Option #1: serving BS 920 configures a threshold (e.g. threshold #1 as described in the embodiments of Figure 6) to UE 910. For example, if the channel quality of a serving cell of serving BS 920 is worse than the configured threshold, UE 910 is triggered to perform a prediction, i.e. performing a prediction operation. In some cases, an AS layer of UE 910 may indicate an upper layer of UE 910 or an AI entity of UE 910 to perform an AI based prediction operation. For example, the threshold may be associated with an L1 measurement result and/or an L3 measurement result.

Option #2: an AS layer of UE 910 may deliver one or more measurement results of a serving cell of serving BS 920 to an upper layer of UE 910 or an AI entity of UE 910. Then, the upper layer or the AI entity of UE 910 may determine whether to start or stop an AI based prediction operation.

In operation 902, there may be following different embodiments if different configuration information is configured to UE 910.

(1) On RLF prediction:

If serving BS 920 transmits a configuration (e.g. configuration #1) to UE 910 to predict an RLF within a time duration (e.g. time duration #1) . The start point of time duration #1 is the reception of configuration #1 or absolute time (e.g. UTC time) . UE 910 may start a timer (e.g. timer #1) for an RLF prediction upon reception of configuration #1 of an RLF prediction or at the absolute time. Once timer #1 for the RLF prediction expires, UE 910 stops the RLF prediction.

(2) On ping-pong handover prediction:

a) If serving BS 920 transmits a configuration (e.g. configuration #2) to UE 910 to predict a ping-pong handover within a time duration (e.g. time duration #2) . The start point of time duration is the reception of configuration #2 related to a ping-pong handover or absolute time (e.g. UTC time) . UE 910 may start a timer (e.g. timer #2) for a ping-pong handover prediction upon reception of configuration #2 of ping-pong handover prediction or at the absolute time. Once timer #2 for ping-pong handover prediction expires, UE 910 may stop the ping-pong handover prediction.

b) Regarding a ping-pong handover, the threshold (e.g. threshold #2) for a period staying at the candidate cell may be configured to UE 910 which will be used to determine whether a ping-pong will occur.

(3) On short of stay prediction:

a) Regarding a short of stay prediction, a threshold (e.g. threshold #3) for a period staying at the candidate cell will be configured to UE 910 which may be used to determine whether a short of stay will occur. If the period staying at the candidate cell is less than the configured threshold, this handover will be "short of stay after handover" .

In some embodiments of operation 902, serving BS 920 may configure UE 910 with specific contents of prediction, i.e. what contents can be predicted by UE 910. For example, the contents of prediction may include at least one of the following:

(1) Whether an RLF occurs.

(2) Whether an RLF occurs within a time duration.

(3) A suitable cell if re-establishment procedure is performed.

(4) One or more measurement results or predicted measurement results of a serving cell.

(5) One or more measurement results or predicted measurement results of a neighbor cell (e.g. one or more candidate cells) .

In operation 903, UE 910 performs a prediction for an RLF, a ping-pong handover, and/or a short of stay after handover.

In some embodiments, UE 910 may start to perform the prediction based on the configured condition. For example, if the channel quality of the serving cell is worse than the configured threshold, UE 910 is triggered to perform prediction. Or, an AS layer of UE 910 may indicate an upper layer of UE 910 or an AI entity of UE 910 to perform the prediction. For example, the threshold is based on an L1 measurement result or an L3 measurement result. If the configured condition is not met, UE 910 may stop the prediction.

In operation 904, UE 910 transmits, to serving BS 920, a report (e.g. a prediction report) related to the RLF prediction, the ping-pong handover prediction, and/or the short of stay after handover to serving BS 920. In some embodiments, the report may include at least one of the following:

(1) An indication to indicate "be about to occur RLF" or "RLF will occur" (e.g. RLF prediction) .

(2) A time point at or after with an RLF will occur.

(3) A predicted failure cause, which may be at least one of the following:

a) timer T310 expiry; or

b) timer T312 expiry; or

c) upon an random access problem indication from MCG; or

d) a maximum number of RLC retransmissions has been reached; or

e) if connected as an IAB-node, upon BH RLF indication received; or

f) upon receipt of consistent uplink LBT failure indication.

(4) A time duration within which UE 910 predicts that RLF will occur. For example, UE 910 predicts that RLF will occur within a time window [t1, t2] (e.g. time duration #1) .

(5) An indication to indicate that a ping-pong handover will occur if UE 910 switches to a candidate cell.

(6) A time window (e.g. time duration #2) within which a ping-pong handover will occur if UE 910 switches to the candidate cell.

(7) A candidate cell list (e.g. candidate cell list #1) related to a short of stay. For example, UE 910 predicts that after switching towards one candidate cell among the candidate cell list, time duration within which it will stay at the one candidate cell is less than the configured threshold (e.g. threshold #3) .

(8) Time duration related to a short of stay. In an example, the short of stay is predicted to occur if UE 910 switches to the candidate cell within the time duration, e.g. a time window [t3, t4] .

(9) Time duration list (e.g. time duration list #1) related to a short of stay, which may include accurate time duration predicted staying at a candidate cell after switching towards the candidate cell. In an example, UE 910 is predicted to stay at a candidate cell (e.g. candidate cell #1) during time duration (e.g. time duration #a) within time duration list #1 after UE 910 switches from the serving cell to candidate cell #1 and before UE 910 switches from candidate cell #1 to another candidate cell (e.g. candidate cell #2) .

(10) A measurement result prediction for one or more candidate cells, e.g. the best channel quality or some candidate cells with best measurement results.

(11) An accuracy rate of the prediction operation performed by UE 910, e.g. 80%.

(12) A suitable cell if re-establishment procedure is performed by UE 910.

In operation 905, after serving BS 920 receives the report related to the prediction operation performed by UE 910, serving BS 920 may prepare a candidate cell for UE 910.

Figure 10 illustrates a schematic diagram of a prediction operation in accordance with aspects of the present disclosure. Details described in all other embodiments of the present disclosure are applicable for the embodiments shown in Figure 10.

In the exemplary flowchart 1000 as shown in Figure 10, in operation 1001, UE 1010 accesses serving BS 1020 (e.g. serving gNB) via MCG only or a DC. In some implementations, UE 1010 may be configured with measurement configuration information related to L1 measurement and/or L3 measurement. UE 1010 may send an L1 measurement report or an L3 measurement report to serving BS 1020, e.g. in operation 1001.

In operation 1002, serving BS 1020 transmits configuration information to UE 1010 to predict an RLF. Different operations may be performed according to different embodiments, e.g. Option #A and Option #B as below.

Option #A: serving BS 1020 configures a threshold (e.g. threshold #1 as described in the embodiments of Figure 6) to UE 1010. For example, if the channel quality of a serving cell of serving BS 1020 is worse than the configured threshold, UE 1010 is triggered to perform a prediction, i.e. performing a prediction operation for an RLF. In some cases, an AS layer of UE 1010 may indicate an upper layer of UE 1010 or an AI entity of UE 1010 to perform an AI based prediction operation. For example, the threshold may be associated with an L1 measurement result and/or an L3 measurement result.

Option #B: an AS layer of UE 1010 may deliver one or more measurement results of a serving cell of serving BS 1020 to an upper layer of UE 1010 or an AI entity of UE 1010. Then, the upper layer or the AI entity of UE 1010 may determine whether to start or stop an AI based prediction operation.

In operation 1002, if serving BS 1020 transmits a configuration (e.g. configuration #1) to UE 1010 to predict an RLF within a time duration (e.g. time duration #1) . The start point of time duration #1 is the reception of configuration #1 or absolute time (e.g. UTC time) . UE 1010 may start a timer (e.g. timer #1) for an RLF prediction upon reception of configuration #1 of an RLF prediction or at the absolute time. Once timer #1 for the RLF prediction expires, UE 1010 stops the RLF prediction.

In some embodiments of operation 1002, serving BS 1020 may configure UE 1010 with specific contents of prediction, i.e. what contents can be predicted by UE 1010. For example, the contents of prediction may include at least one of the following:

(1) Whether an RLF occurs.

(2) Whether an RLF occurs within a time duration.

(3) A suitable cell if re-establishment procedure is performed.

In operation 1003, UE 1010 performs a prediction for an RLF for a serving cell. In some embodiments, UE 1010 may start to perform the prediction based on the configured condition. For example, if the channel quality of the serving cell is worse than the configured threshold, UE 1010 is triggered to perform prediction. Or, an AS layer of UE 1010 may indicate an upper layer of UE 1010 or an AI entity of UE 1010 to perform the prediction. For example, the threshold is based on an L1 measurement result or an L3 measurement result. If the configured condition is not met, UE 1010 may stop the prediction.

In operation 1004, UE 1010 is triggered to execute a handover, e.g. upon reception of a handover command or at least one CHO condition is met.

In operation 1005, different operations may be performed in different embodiments as below.

On RLF prediction for a source cell (i.e. the serving cell) :

(1) In some embodiments of operation 1005, UE 1010 may stop performing an RLF prediction for a source cell when UE 1010 is triggered to execute handover. Alternatively, an AS layer of UE 1010 may indicate to an upper layer or an AI entity of UE 1010 to stop the RLF prediction upon an execution of the handover.

(2) In some embodiments of operation 1005, UE 1010 may stop a timer (e.g. timer #1) for the RLF prediction for the source cell if the timer for the RLF prediction for the source cell is running.

On RLF prediction for a target cell:

(1) In some embodiments of operation 1005, UE 1010 may start an RLF prediction for a target cell (e.g. target cell #1) if the configuration for RLF prediction is included in an RRC reconfiguration message from the target cell.

(2) Furthermore, if UE1010 predicts that an RLF will occur in the target cell when timer T304 is running, UE 1010 may report the RLF prediction result via an RRC reconfiguration complete message or after completing the handover in operation 1006.

In some implementations of operation 1006, UE 1010 may transmit, to the target cell (e.g. target cell #1) , a prediction report which includes at least one of the following:

(4) a predicted failure cause of the RLF in the candidate cell. For example, the predicted failure cause includes at least one of the following failure causes:

a) timer T310 expiry;

b) timer T312 expiry;

c) upon receipt of a random access problem indication from MCG;

d) the maximum number of RLC retransmissions has been reached;

e) if connected as an IAB-node, upon BH RLF indication received; or

f) upon receipt of consistent uplink LBT failure indication.

Figure 11 illustrates a schematic diagram of a prediction operation in accordance with aspects of the present disclosure. Details described in all other embodiments of the present disclosure are applicable for the embodiments shown in Figure 11.

In the exemplary flowchart 1100 as shown in Figure 11, in operation 111, UE 110 accesses serving BS 120 (e.g. serving gNB) via MCG only or a DC.

In some implementations, UE 110 may be configured with measurement configuration information related to L1 measurement and/or L3 measurement. UE 110 may send an L1 measurement report or an L3 measurement report to serving BS 120, e.g. in operation 111.

In operation 112, serving BS 120 transmits configuration information to UE 110. In some implementations, serving BS 120 configures UE 110 to predict a ping-pong handover towards a set of candidate cells and/or a short of stay after a handover related to a set of candidate cells. Different operations may be performed according to different embodiments, e.g. Option #X and Option #Y as below.

Option #X: serving BS 120 configures a threshold (e.g. threshold #1 as described in the embodiments of Figure 6) to UE 110. For example, if the channel quality of a serving cell of serving BS 120 is worse than the configured threshold, UE 110 is triggered to perform a prediction, i.e. performing a prediction operation. In some cases, an AS layer of UE 110 may indicate an upper layer of UE 110 or an AI entity of UE 110 to perform an AI based prediction operation. For example, the threshold may be associated with an L1 measurement result and/or an L3 measurement result.

Option #Y: an AS layer of UE 110 may deliver one or more measurement results of a serving cell of serving BS 120 to an upper layer of UE 110 or an AI entity of UE 110. Then, the upper layer or the AI entity of UE 110 may determine whether to start or stop an AI based prediction operation.

In operation 112, there may be following different embodiments if different configuration information is configured to UE 110.

(1) On ping-pong handover prediction:

a) If serving BS 120 transmits a configuration (e.g. configuration #2) to UE 110 to predict a ping-pong handover within a time duration (e.g. time duration #2) . The start point of time duration is the reception of configuration #2 related to a ping-pong handover or absolute time (e.g. UTC time) . UE 110 may start a timer (e.g. timer #2) for a ping-pong handover prediction upon reception of configuration #2 of ping-pong handover prediction or at the absolute time. Once timer #2 for ping-pong handover prediction expires, UE 110 may stop the ping-pong handover prediction.

b) Regarding a ping-pong handover, the threshold (e.g. threshold #2) for a period staying at the candidate cell may be configured to UE 110 which will be used to determine whether a ping-pong will occur.

(2) On short of stay prediction:

a) Regarding a short of stay prediction, a threshold (e.g. threshold #3) for a period staying at the candidate cell will be configured to UE 110 which may be used to determine whether a short of stay will occur. If the period staying at the candidate cell is less than the configured threshold, this handover will be "short of stay after handover" .

In operation 113, UE 110 performs a prediction for a ping-pong handover and/or a short of stay after handover.

In some embodiments, UE 110 may start to perform the prediction based on the configured condition. For example, if the channel quality of the serving cell is worse than the configured threshold, UE 110 is triggered to perform prediction. Or, an AS layer of UE 110 may indicate an upper layer of UE 110 or an AI entity of UE 110 to perform the prediction. For example, the threshold is based on an L1 measurement result or an L3 measurement result. If the configured condition is not met, UE 110 may stop the prediction.

In operation 114, UE 110 is triggered to execute a handover, e.g. upon reception of a handover command or at least one CHO condition is met.

In operation 115, different operations may be performed in different embodiments as below, e.g. Option #M and Option #N as below.

Option #M: UE 110 may stop performing the prediction operation when UE 110 is triggered to execute the handover. Alternatively, an AS layer of UE 110 indicates to an upper layer or an AI entity of UE 110 to stop the prediction operation upon an execution of the handover.

Option #N: UE 110 may continue performing the prediction operation when UE 110 is performing a handover towards a candidate cell (e.g. cell #1) .

In operation 116, different operations may be performed in different embodiments as below.

On ping-pong handover prediction:

In some embodiments of operation 116, if UE 110 predicts that a ping-pong handover towards a candidate cell (e.g. candidate cell #m) of candidate BS 130 (e.g. a target gNB) will occur, UE 110 will report predication report related to a ping-pong handover to candidate cell #m of candidate BS 130. For example, the ping-pong handover prediction can be reported in an RRC reconfiguration complete message towards candidate cell #m.

In an embodiment, candidate BS 130 may transfer the received predication report to source BS 120 via Xn interface, e.g. in operation 117 (optional) . The prediction report can be transmitted together with or within a release indication message transmitted by candidate BS 130 to source BS 120. In this way, source BS 120 may not release the context of UE 110, e.g. in operation 118 (optional) . Instead, source BS 120 may prepare an RRC reconfiguration message for handover and transmit it to candidate BS 130, e.g. in operation 119 (optional) .

On short of stay prediction:

In some embodiments of operation 116, if UE 110 predicts that a short of stay towards a candidate cell (e.g. candidate cell #a) of candidate BS 130 (e.g. a target gNB) will occur, UE 110 will report information indicating that the short of stay after the handover is predicted to occur if UE 110 switches to candidate cell #a. For instance, UE 110 may report a prediction report related to the short of stay to candidate cell #a. In an example, the prediction report related to the short of stay is reported together with the RRC reconfiguration complete message, e.g. in separate messages to candidate cell #a. In another example, the prediction report related to the short of stay is reported within the RRC reconfiguration complete message to candidate cell #a.

In an embodiment of operation 116, information regarding another candidate cell to which UE 110 will switch from candidate cell #a, i.e. a next candidate cell (e.g. candidate cell #b) , may also be reported to candidate cell #a of candidate BS 130, e.g. in the prediction report.

In another embodiment of operation 116, time duration or a short time period, within which UE 110 is predicted to stay at candidate cell #a (i.e. the time after switching from the serving cell to candidate cell #a and before switching from candidate cell #a to candidate cell #b) , may also be reported to candidate cell #a of candidate BS 130, e.g. in the prediction report.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A user equipment (UE) , comprising:

at least one memory; and

at least one processor coupled to the at least one memory and configured to cause the UE to:

receive, from a serving cell of the UE, configuration information used for the UE to predict at least one of the following:

a radio link failure (RLF) ;

a ping-pong handover towards at least one candidate cell; or

a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and

perform a prediction operation based on the configuration information.
The UE of Claim 1, wherein the processor of the UE is configured to report, to the serving cell, capability regarding whether to support the prediction operation related to at least one of the RLF, the ping-pong handover or the short of stay after the handover.
The UE of Claim 1, wherein the processor of the UE is configured to receive, from the serving cell, a configuration regarding a threshold of a channel quality of the serving cell to trigger to perform the prediction operation.
The UE of Claim 3, wherein the processor of the UE is configured to:

deliver, by an access stratum (AS) layer of the UE to an upper layer or an artificial intelligence (AI) entity of the UE, information indicating to perform the prediction operation if the channel quality of the serving cell is less than the configured threshold.
The UE of Claim 1, wherein the processor of the UE is configured to:

deliver, by an access stratum (AS) layer of the UE to an upper layer or an artificial intelligence (AI) entity of the UE, one or more measurement results of the serving cell; and

determine, by the upper layer or the AI entity of the UE, whether to start or stop performing the prediction operation based on the one or more measurement results.
The UE of Claim 1, wherein the processor of the UE is configured to receive at least one of the following from the serving cell:

a first configuration regarding first time duration used to predict whether the RLF will occur;

a second configuration regarding second time duration used to predict whether the ping-pong handover towards a candidate cell will occur;

a configuration regarding a first threshold used to predict whether the ping-pong handover will occur; or

a configuration regarding a second threshold used to predict whether the short of stay after the handover will occur.
The UE of Claim 6, wherein the first configuration includes information of a first timer related to the first time duration, wherein start time of the first timer is a time point of receiving the first configuration or an absolute time point, and wherein the processor of the UE is configured to:

start performing the prediction operation related to the RLF at the start time of the first timer; and

stop performing the prediction operation related to the RLF upon an expiry of the first timer.
The UE of Claim 6, wherein the second configuration includes information of a second timer related to the second time duration, wherein start time of the second timer is a time point of receiving the second configuration or an absolute time point, and wherein the processor of the UE is configured to:

start performing the prediction operation related to the ping-pong handover at the start time of the second timer; and

stop performing the prediction operation related to the ping-pong handover upon an expiry of the second timer.
The UE of Claim 6, wherein the processor of the UE is configured to:

predict that the ping-pong handover will occur if a time period staying at the at least one candidate cell is less than the first threshold; or

predict that the short of stay will occur if a time period staying at the at least one candidate cell after the handover is less than the second threshold.
The UE of any of Claims 1-9, in response to predicting that at least one of the RLF, the ping-pong handover, or the short of stay after the handover will occur, the processor of the UE is configured to transmit a prediction report to the serving cell.
The UE of Claim 10, in response to predicting that the RLF will occur in the serving cell, the prediction report includes at least one of the following:

information indicating that the RLF is predicted to occur in the serving cell;

a time point at or after which the RLF is predicted to occur in the serving cell;

a time window within which the RLF is predicted to occur in the serving cell; or

a predicted failure cause of the RLF in the serving cell.
The UE of Claim 10, in response to predicting that the ping-pong handover will occur, the prediction report includes at least one of the following:

information indicating that the ping-pong handover is predicted to occur if the UE switches to a candidate cell; or

a time window, wherein the UE is predicted to switch from the candidate cell back to the serving cell if the UE switches from the serving cell to the candidate cell within the time window.
The UE of Claim 10, in response to predicting that the short of stay after the handover will occur, the prediction report includes at least one of the following:

information indicating that the short of stay after the handover is predicted to occur if the UE switches to a candidate cell;

a candidate cell list, wherein the candidate cell list includes a first candidate cell, and the short of stay is predicted to occur at the first candidate cell after the UE switches to the first candidate cell; or

a time duration list, wherein the time duration list includes third time duration, and the UE is predicted to stay at the first candidate cell during the third time duration after the UE switches from the serving cell to the first candidate cell and before the UE switches from the first candidate cell to another candidate cell.
A serving base station (BS) , comprising:

at least one memory; and

at least one processor coupled to the at least one memory and configured to cause the serving BS to:

receive, from a user equipment (UE) , capability regarding whether to support a prediction operation related to at least one of the following:

a radio link failure (RLF) ;

a ping-pong handover towards at least one candidate cell; or

a short of stay at the at least one candidate cell after a handover towards the at least one candidate cell; and

transmit, to the UE, configuration information regarding the prediction operation.
The serving BS of Claim 14, wherein the processor of the serving BS is configured to transmit, to the UE, a configuration regarding a threshold of a channel quality of a serving cell of the UE to trigger the UE to perform the prediction operation.
The serving BS of Claim 14, wherein the processor of the serving BS is configured to transmit at least one of the following to the UE:

a first configuration regarding first time duration used to predict whether the RLF will occur;

a second configuration regarding second time duration used to predict whether the ping-pong handover towards a candidate cell will occur;

a configuration regarding a first threshold used to predict whether the ping-pong handover will occur; or

a configuration regarding a second threshold used to predict whether the short of stay after the handover will occur.
The serving BS of Claim 16, wherein the first configuration includes information of a first timer related to the first time duration, wherein start time of the first timer is a time point of receiving the first configuration or an absolute time point, and wherein the prediction operation related to the RLF is started to be performed at the start time of the first timer and is stopped to be performed upon an expiry of the first timer.
The serving BS of Claim 16, wherein the second configuration includes information of a second timer related to the second time duration, wherein start time of the second timer is a time point of receiving the second configuration or an absolute time point, and wherein the prediction operation related to the ping-pong handover is started to be performed at the start time of the second timer and is stopped to be performed upon an expiry of the second timer.
The serving BS of any of Claims 14-18, in response to the UE predicting that the RLF will occur in a serving cell of the UE, the processor of the serving BS is configured to receive, from the UE, a prediction report including at least one of the following:

information indicating that the RLF is predicted to occur in the serving cell;

a time point at or after which the RLF is predicted to occur in the serving cell;

a time window within which the RLF is predicted to occur in the serving cell; or

a predicted failure cause of the RLF in the serving cell.
A candidate base station (BS) , comprising:

at least one memory; and

at least one processor coupled to the at least one memory and configured to cause the candidate BS to:

receive, from a serving BS of a user equipment (UE) , a request for handover towards a candidate cell of the candidate BS;

transmit, to the serving BS, an acknowledge message related to the candidate cell in response to receipt of the request for handover; and

receive, from the UE, a prediction report related to at least one of the following:

a radio link failure (RLF) in the candidate cell;

a ping-pong handover towards the candidate cell; or

a short of stay at the candidate cell after a handover towards the candidate cell.