CN116419308A

CN116419308A - Connection establishment failure reporting method and user equipment

Info

Publication number: CN116419308A
Application number: CN202111681375.5A
Authority: CN
Inventors: 常宁娟; 刘仁茂
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2021-12-31
Filing date: 2021-12-31
Publication date: 2023-07-11
Also published as: WO2023125649A1

Abstract

The disclosure provides a connection establishment failure reporting method and user equipment. The connection establishment failure reporting method comprises the following steps: the User Equipment (UE) initiates a Small Data Transmission (SDT) process based on random access; the UE judges that the SDT process fails; and the UE storing CEF information in a connection establishment failure, CEF, report, the CEF information comprising at least one of: first information indicating that the failure procedure is for SDT; and second information indicating that the failure occurred in a subsequent transmission stage of the SDT procedure.

Description

Connection establishment failure reporting method and user equipment

Technical Field

The present disclosure relates to the field of wireless communication technologies, and more particularly, to a connection establishment failure reporting method and a corresponding user equipment.

Background

The aim of optimizing the network performance can be achieved through network optimization in the wireless network. The method generally performs means such as data acquisition and data analysis on the existing deployed and operated network, finds out reasons influencing the network quality, and improves the network performance by means such as modifying configured network parameters, adjusting network structures and deployed devices. For Self-configuring and Self-optimizing networks (Self-configuration and Self-Optimization Network, SON), a process is referred to that automatically adjusts the network based on measurements/performance measurements of user equipment and/or base stations. The network side may configure the UE to perform measurements for SON. The SON functions include many aspects such as an automatic neighbor relation function (ANR, automatic Neighbour Relation Function) for reducing the neighbor management burden of operators, a mobility load balancing function (MLB, mobility Load Balancing) for balancing the responsibility between different cells, a mobility robustness optimization function (MRO, mobility Robustness Optimization) for optimizing mobility performance, a random access channel optimization function for optimizing random access channel parameters, and a radio link failure reporting function for optimizing coverage and MRO, etc.

Furthermore, minimization of drive tests (Minimization of Drive Tests, MDT) technology is also an important means for operators to optimize networks. Relevant parameters of network optimization are obtained from the drive test data obtained by the UE, and based on analysis of the data, the state of network deployment and operation is obtained, so that a decision is made on how to improve the operation state of the network. The main application scenarios of MDT are coverage optimization, capacity optimization, mobility management optimization, qoS parameter optimization, public channel parameter configuration optimization and the like.

In release 17 and previous versions of the system, the connection establishment failure (Connection Establishment Failure, CEF) report is a record of the network conditions by the UE when the initial connection establishment occurs, for the optimization of network coverage problems at the network side.

The 3GPP RAN2 working group is currently conducting a release 17 study (see 3GPP document RP-193252 (Work Item on NR small data transmissions in INACTIVE state)) for short small data transfer (Small Data Transmission, SDT) project. The purpose of this study is to optimize the signaling overhead and power consumption for small-sized data traffic that is not frequently sent by users. For a UE (User Equipment) in a radio resource control Inactive state (Radio Resource Control _inactive, rrc_inactive), transmission of some infrequent small-size data services (such as instant information, on-line heartbeat signals, periodic information of an intelligent wearable device or a sensor, and periodic meter reading service brought by an intelligent metering device) makes the UE need to enter a radio resource control CONNECTED state rrc_connected state to perform transmission of small-size data packets, so that signaling overhead brings about a reduction in network performance, and meanwhile, energy consumption of the UE is also greatly consumed.

The present disclosure is directed to implementing the failure information reporting problem in NR networks, and further, to implementing the CEF reporting problem in networks for supporting SDT.

Disclosure of Invention

The main objective of the present disclosure is to provide a connection establishment failure reporting method and a user equipment, so as to implement reporting of SDT related performance information and random access information setting problem when implementing CEF reporting in SDT scenario in a system supporting SDT.

According to a first aspect of the present disclosure, there is provided a connection establishment failure reporting method, including: the User Equipment (UE) initiates a Small Data Transmission (SDT) process based on random access; the UE judges that the SDT process fails; and the UE storing CEF information in a connection establishment failure, CEF, report, the CEF information comprising at least one of: first information indicating that the failure procedure is for SDT; and second information indicating that the failure occurred in a subsequent transmission stage of the SDT procedure.

In the connection establishment failure reporting method of the first aspect, the CEF information may further include: location information, failed cell identity, measurement results of failed cells or neighbor cells.

In the connection establishment failure reporting method of the first aspect, the UE may determine that the SDT procedure fails when an SDT timer started in the SDT procedure initiated by the UE expires.

In the connection establishment failure reporting method of the first aspect, the UE may save the CEF information in the CEF report if the SDT timer expires before the UE receives a first resource scheduling command for scheduling uplink or downlink data.

In the connection establishment failure reporting method of the first aspect, the UE may determine that the SDT procedure fails when the radio link control RLC transmission reaches the maximum number of times.

In the connection establishment failure reporting method of the first aspect, when one or more random access RA procedures are performed in the SDT procedure, the CEF information may include RA information related to a latest RA procedure among the one or more RA procedures.

In the connection establishment failure reporting method of the first aspect, when one or more random access RA procedures are performed in the SDT procedure, RA information related to the one or more RA procedures may be included in the CEF information.

According to a second aspect of the present disclosure, there is provided a connection establishment failure reporting method, including: the User Equipment (UE) initiates a Small Data Transmission (SDT) process based on a configuration permission mode; the UE judges that the SDT process fails; the UE saves CEF information in a connection establishment failure CEF report, and information related to random access in the CEF information is set to an arbitrary value or a specific value.

In the connection establishment failure reporting method of the second aspect, the UE may determine that the SDT procedure fails when an SDT timer started in the SDT procedure initiated by the UE expires or when radio link control RLC transmission reaches the maximum number of times.

According to a third aspect of the present disclosure, there is provided a user equipment comprising: a processor; and a memory storing instructions; the instructions, when executed by the processor, perform the connection establishment failure reporting method described above.

Effects of the invention

According to the CEF reporting method executed by the user equipment and the user equipment, the reporting of the SDT related performance information and the random access information setting problem when CEF reporting is realized in an SDT scene can be realized in a system supporting the SDT.

Drawings

The above and other features of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which:

fig. 1 is a schematic flow chart showing a random access based SDT procedure.

Fig. 2 is a schematic flow chart showing an SDT procedure based on CG-SDT mechanism.

Fig. 3 is a schematic flow chart showing a connection establishment failure reporting method in embodiment 1 of the present invention.

Fig. 4 is a schematic flow chart showing a connection establishment failure reporting method in embodiment 2 of the present invention.

Fig. 5 is a schematic flow chart showing a connection establishment failure reporting method in embodiment 3 of the present invention.

Fig. 6 shows a block diagram of a user device according to an embodiment of the present disclosure.

Detailed Description

Other aspects, advantages, and salient features of the present disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the present disclosure.

In the present disclosure, the terms "include" and "comprise," along with their derivatives, are intended to be inclusive, rather than limiting; the term "or" is inclusive, meaning and/or.

In this specification, the various embodiments described below for the purpose of describing the principles of the present disclosure are illustrative only and should not be construed in any way as limiting the scope of the disclosure. The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the present disclosure defined by the claims and their equivalents. The following description includes numerous specific details to aid in understanding, but these details should be construed as exemplary only. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness. Furthermore, the same reference numerals are used for similar functions and operations throughout the drawings.

Various embodiments according to the present disclosure are specifically described below with an NR mobile communication system as an example application environment. However, it should be noted that the present disclosure is not limited to the following embodiments, but is applicable to many other wireless communication systems, such as an LTE system connected to a 5G core network, and the like.

The base station in the present disclosure may be any type of base station, including a Node B, an enhanced base station eNB, and a 5G communication system base station gNB; or a micro base station, a pico base station, a macro base station, a home base station, etc.; the cell may also be a cell under any of the above base stations, the cell may also be a beam, a transmission point (Transmission point, TRP), the base station may also be a Central Unit (gNB-Central Unit, gNB-CU) or a Distributed Unit (gNB-Distributed Unit, gNB-DU) constituting the base station. Unless specifically stated otherwise, in the present disclosure, concepts of cells and base stations may be interchanged; the LTE system is also used to refer to the 5G and later LTE systems (e.g. called the LTE system, or the LTE system that may be connected to the 5G core network), while LTE may be replaced with evolved universal terrestrial radio access (Evolved Universal Terrestrial Radio Access, E-UTRA) or evolved universal terrestrial radio access network E-UTRAN. Different embodiments may also work in combination, such as the same variables/parameters/nouns etc. in different embodiments are explained identically. Cancel, release, delete, empty, clear, etc. may be replaced. Execution, use, and application alternatives. Configuration and reconfiguration may be replaced. Monitoring (monitor) and detection (detect) may be substituted. Initiation and triggering may be substituted.

Some of the existing mechanisms to which this disclosure relates are described first below. It is noted that some of the designations in the description below are illustrative only and not limiting, and other designations are possible.

CEF report:

connection establishment failure (Connection Establishment Failure, CEF) reporting is supported in the NR system. The network side evaluates the coverage condition of the network, such as whether the coverage of the cell is enough or not, whether coverage holes exist in the network deployment or not, and the like, by collecting the information in the CEF report reported by the UE.

When the connection fails (such as the RRC connection establishment procedure fails or the RRC connection recovery procedure fails), the UE saves the information corresponding to the failure event in the UE variable VarConnEstFailReport corresponding to the CEF report. Generally, when the RRC connection setup procedure monitoring timer (e.g., T300) expires, the UE considers the RRC connection setup procedure to fail; when the RRC connection recovery procedure monitoring timer (e.g., T319) expires, the UE considers the RRC connection recovery procedure to fail. When the UE has a saved CEF report in the variable VarConnEstFailReport, the UE includes a connestfailimable information element in the RRC message (e.g., RRC resume complete message, RRC setup complete message, RRC reconfiguration complete message) to inform the base station that there is a saved CEF report. The base station issues a ueincarnationrequest message to the UE, where the UE includes a CEF report request indication (connEstFailReportReq information element) for requesting the UE to report the saved CEF report information. After receiving the UEinformationRequest message containing the indication, the UE reports the saved CEF report (ConnEstFailReport information element) to the base station in a ueinformationreport message. The connection failure event in release 16 NR system includes RRC connection establishment procedure failure or RRC connection recovery procedure failure, but the connection failure event in this disclosure is not limited to these two cases, such as failure of RRC reestablishment procedure (e.g., timer T301 timeout or T311 timeout) or failure of small data transfer (Small Data Transmission, SDT) procedure (RRC timer timeout related to small data transfer)

The CEF report supported in the NR system of release 17 and above includes the following: the measurement result of the failed cell, the location information, the measurement result of the neighbor cell, the number of connection failures, the random access information, and the time elapsed from the occurrence of the connection failure event to the reporting. Wherein, the measurement result of the failed cell refers to the measurement result of the serving cell/camping cell (such as reference signal measurement power RSRP, reference signal measurement quality RSRQ, signal-to-interference-and-noise ratio SINR, etc.) when the connection failure occurs; the measurement results of the neighbor cells refer to the measurement results of one or more neighbor cells when a connection failure event occurs; the location information refers to the absolute location where the connection failure event occurs, and the UE with the positioning function can record the information; the number of connection failures refers to the latest value of the continuous connection failure process in the same cell; the random access information refers to information of a random access procedure performed in a connection failure procedure (including information of each random access attempt such as perrainfoslist information element). The perRAInfoList information element containing random access information lists information related to each random access attempt according to the time sequence of the random access attempt, such as a beam index related to each random access attempt, whether contention is detected, whether downlink RSRP is greater than a configured threshold value, whether rollback (fallback) is performed due to the receipt of a rollback random access response, the number of random access attempts performed continuously on each beam, and the like. The beam is a synchronization signal block (Synchronization Signal Block, SSB) or a channel state information reference signal (Channel State Information ReferenceSignal, CSI-RS).

Only detailed information on the last connection establishment/restoration failure is stored in the CEF report of the version 16, i.e. the above-mentioned information in the CEF report except for the connection failure number is for the last connection failure. Multiple CEF reports are introduced in the system of release 17 (at this time, the CEF report may be stored in the UE variable VarConnEstFailReportList), that is, the UE may store and report detailed information of multiple failure events to the network side, and each CEF report may correspond to one or more failure events. The connection failure in this disclosure includes RRC connection setup failure, RRC connection recovery failure, and SDT procedure failure, unless otherwise noted.

Radio link failure reporting mechanism:

in the NR systems of versions 16 and 17, the UE generates and saves a Radio link Failure Report (RLF Report) when a Radio link Failure (Radio LinkFailure, RLF) or a Handover Failure (HOF) occurs, and saves the Radio link Failure information in the UE variable VarRLF-Report. After restoring the connection with the network side (e.g., through an RRC reestablishment procedure or an RRC establishment procedure for establishing a new connection), the UE may inform the network side of a radio link failure report (rlf-infoailable information element indicated) available thereon through an RRC message. For example, the UE may inform the network side that the UE has a saved available radio link failure report in an RRC reestablishment complete message (rrcreestablischentcomplete) during RRC connection reestablishment, an RRC reconfiguration complete message (rrcreceonfigurationcomplete) during RRC connection reconfiguration, an RRC establishment complete message (rrcsetup complete) during RRC connection establishment, or an RRC restoration complete message (rrcresceneecomplete) during RRC connection restoration. After receiving the indication, the network side may request the UE to report its saved radio link failure report through an RRC message (rlf-ReportReq information element in the UEInformationRequest message indicates the request). The UE will Report the saved radio link failure Report (rlf-Report information element in the ueinfo response message) to the network side in a response RRC message. The radio link failure report acquired by the network side is used for network optimization, such as network coverage and mobile robustness optimization. The radio link failure report may include: the measurement results of the source cell and the neighbor cell available when the link fails, the location information, the primary cell identifier of the occurrence of the link failure, the link failure type (RLF or HOF), the RLF reason, the time elapsed from the connection failure to the reporting of the radio link failure, the time elapsed since the last time the handover command was received to the connection failure (denoted as timecon failure information element), the cell identifier of the UE re-accessing the network, i.e. the RRC reestablishment cell identifier, and the like. If the failure is due to random access or is accompanied by an unsuccessful random access procedure, the radio link failure report also includes random access procedure information. The information of the random access procedure includes: and transmitting the cell information (global cell identification, tracking area code or physical cell identification and carrier frequency) where the random access preamble is located, the random access destination information and the random access public information. The random access public information includes reference downlink frequency information (such as absolute frequency of Point a, subcarrier spacing, bandwidth location information locationband, etc.) associated with a random access process and associated RA information of each random access attempt arranged according to time sequence. The associated RA information for each random access attempt includes a beam index value, a number of consecutive random access attempts on the beam (i.e., a number of transmissions of a corresponding consecutive random access preamble on the beam), an indication of whether random access contention is detected, and an indication of whether a reference signal received strength (Reference Signal Received Power, RSRP) of the corresponding beam on a random access resource used by the random access attempt is above a configured threshold.

Small data transfer SDT mechanism:

one of the research objectives of the small data transfer SDT project is to implement small data packet transfer in rrc_inactive state. There are two implementations of the SDT mechanism: random Access-based SDT (RA-SDT) and Configured Grant-based SDT (CG-SDT).

Fig. 1 is a schematic flow chart showing a random access based SDT procedure. As shown in fig. 1, in the SDT process based on random access, when there is data to be transmitted on the radio bearer configured with SDT on the UE in the rrc_inactive state, the UE sends a small data transmission request to the network side through the SDT dedicated PRACH resource in the random access process, and the network side knows that the UE will perform small data transmission in the rrc_inactive state, so that the UE is not configured to enter the RRC connected state. Then, the UE sends the small data carried in the message a of the two-step random access procedure or the message 3 carried in the four-step random access procedure to the network side, where the message a or the message 3 includes the RRC recovery request message at the same time. If all the small data are contained in the message 3 or the message A and successfully transmitted (even if the data buffer corresponding to the radio bearer or the logic channel which can be SDT is empty), the UE determines that the SDT process is finished after receiving the response message containing the RRC release message of the network side; if the small data is not completely sent (i.e. the uplink buffer memory of the UE still has the small data which is not yet sent), after the random access is completed, the network side schedules the UE to complete the uplink or downlink small data transmission through the UE-specific radio network identifier (e.g. Cell-Radio Network Temprary identifier, C-RNTI), and when the whole small data transmission is completed, the SDT process is ended. In the SDT procedure, if the UE has non-SDT uplink data (data on the radio bearer that is not SDT enabled) arrives, the UE performs uplink data transmission by sending a request indication to the network side to enter the RRC connected state or autonomously fall back to the conventional non-SDT procedure.

Fig. 2 is a schematic flow chart showing an SDT procedure based on CG-SDT mechanism. As shown in fig. 2, in the CG-SDT mechanism, the network side UE configures CG-SDT resources for small data transmissions, typically the CG-SDT configuration is contained in an RRC release message. After receiving the message, the UE releases the RRC connection, enters the rrc_inactive state, and applies CG-SDT configuration. The CG-SDT configuration includes a semi-static uplink grant resource for uplink data transmission and corresponding L2 and L1 configurations, and this resource is generally a periodic resource. When the radio bearer on which the SDT is configured on the UE in the RRC_INACTIVE state has data to be transmitted and CG-SDT initiating conditions are met, the UE does not need to initiate a random access process, but directly uses the configured CG to transmit small data, and completes the remaining small data transmission by monitoring the scheduling information of the base station on a downlink channel.

As previously described, SDT not only supports transmission of a single packet, but may support transmission of multiple packets. In the SDT procedure, the first transmitted data includes common control channel (Common Control Channel, CCCH) data (RRC resume request message) and user plane data, which is referred to as a primary transmission (initial transmission) or a primary physical uplink shared channel (Physical Uplink Shared Channel, PUSCH) transmission, and the later performed transmission of user plane data is referred to as a subsequent transmission (subsequent transmission) or a subsequent PUSCH transmission. In RA-SDT, the initial transmission generally refers to the transmission of message a or message 3, with subsequent transmissions occurring after the random access RA procedure is successfully completed. In CG-SDT, an initial transmission uses allocated CG resources, and subsequent transmissions may use allocated CG resources as well as dynamic grants. The UE will not perform subsequent transmissions until the initial transmission is confirmed to be successful.

In the whole SDT process, the UE is kept in an RRC_INACTIVE state, so that signaling overhead caused by the traditional data transmission process is greatly reduced, the energy consumption of the UE is saved, and meanwhile, the time delay of data transmission can be shortened.

Only if the conditions for initiating the SDT procedure are satisfied, the UE can initiate and use the SDT procedure to transmit data. These conditions may include: the network side configures resources for SDT (such as PRACH configuration dedicated for SDT) through system information or UE dedicated signaling, radio Bearers (RBs) associated with uplink data to be transmitted by the UE are enabled to use SDT procedure, downlink quality of a primary cell (i.e. camping cell in rrc_inactive state) of the UE (such as reference signal received power (Reference Signal Received Power, RSRP) is greater than or equal to a configured link quality threshold TH1, uplink data size to be transmitted by the UE is less than or equal to a configured data size threshold TH2, etc.

When the RRC layer initiates the SDT process, an SDT timer is started, and the RRC recovery request message is sent. The SDT timer is an RRC layer timer for monitoring the SDT procedure, and thus may also be referred to as an SDT failure detection timer. When the SDT procedure is over, the timer is stopped, such as when the UE receives an RRC release message, an RRC reject message, an RRC resume message, or an RRC setup message, or when the UE performs cell reselection, or when the SDT procedure fails. If the timer times out, the SDT is considered to fail, and the UE performs an operation of entering an RRC IDLE state (RRC_IDLE). In the current 3GPP discussion, it has not been decided whether this SDT timer will restart at every uplink transmission or downlink reception in the SDT procedure. If so, the UE restarts the running SDT timer each time it transmits an uplink data packet or receives a downlink data packet or receives an L1 signaling (e.g., physical downlink control channel (Physical Downlink Control Channel, PDCCH)) for scheduling uplink or downlink data. If not, the UE starts the timer only when triggering the SDT process, and stops the timer until all small data transmission is completed, the SDT process is finished or an RRC message for responding to the RRC recovery request message is received by the network side.

The nature of these SDT procedures as described above makes the SDT procedure different from the conventional RRC recovery procedure. As to support multiple small data packets for subsequent transmission, the value of the SDT timer will generally be set longer than the value of the general RRC recovery procedure monitoring timer T319. In one possible scenario, if the value of the SDT timer is set unreasonably, the SDT timer may timeout when the small data has not yet been transmitted, i.e., the timeout of the SDT timer does not necessarily mean that the network link quality is poor. The network side needs to distinguish CEF reports corresponding to SDT process from CEF reports corresponding to conventional RRC recovery/establishment process, so as to collect CEF reports under different scenes and perform more detailed network state monitoring. In addition, in CG-SDT procedure, the UE does not necessarily perform an RA procedure, but in existing CEF mechanism, the UE must include RA related information in the CEF report, which makes how to set RA related information in the CEF report in CG-SDT scenario a problem to be solved. In addition, unlike the conventional RRC recovery procedure in which the UE performs only one RA procedure, in the SDT procedure, especially in RA-SDT, when the UE may initiate more than one RA procedure to acquire uplink resources or uplink synchronization required for subsequent transmission, the RA-related information in the CEF report in the CEF mechanism is now directed to one RA procedure, how to set the RA-related information in the CEF report corresponding to the SDT procedure in which the RA procedure is performed multiple times is also a problem of the present disclosure.

The present disclosure mainly proposes a solution to the above problem related to failure information reporting (such as CEF reporting) in the scenario of supporting SDT, and by using the solution disclosed in the present disclosure, a UE carries SDT related information in the CEF reporting, so that a network side can learn that the CEF reporting is specific to the SDT scenario, thereby acquiring more CEF information related to SDT, differentiating CEF information corresponding to a traditional RRC recovery procedure, collecting network operation data, and performing more refined network parameter optimization such as optimizing random access parameters corresponding to SDT. In addition, the disclosure also provides a method for setting RA related information in the CEF report in the SDT scenario, so that the UE can reasonably or accurately set RA related information in the CEF report. In addition to carrying SDT related information in the CEF report, considering that the SDT failure is different from the previous connection establishment/recovery failure, there is a possibility that the SDT failure may be regarded as similar to the conventional radio link failure RLF, and the disclosure further provides a method for carrying SDT related information in the RLF report, so that the UE may report failure information of the SDT process to the network side by means of the RLF report, so that the network side may obtain operation data of the SDT process in the network, thereby optimizing relevant configuration parameters, such as optimizing random access parameters corresponding to the SDT.

Example 1

Embodiment 1 provides a CEF reporting method in an SDT scenario. Hereinafter, the CEF reporting method in example 1 will be described in detail. Fig. 3 is a schematic flow chart showing a connection establishment failure reporting method in embodiment 1 of the present invention. As shown in fig. 3, the connection establishment failure reporting method in embodiment 1 may include the following steps.

Step 1: the UE initiates a random access based SDT procedure.

Specifically, for example, the UE initiates an SDT procedure and starts an SDT timer.

The SDT timer is a timer running in the RRC layer as described above, and is started along with the initiation of the transmission of the RRC resume request message rrcresmerrequest, and when the SDT timer expires, the SDT procedure is considered to fail, the SDT procedure is ended, and the RRC idle state is entered, and the operation of entering the RRC idle state, such as the release of radio resources and configuration thereof, is performed.

After initiating the SDT procedure, the UE instructs the bottom layer to perform data transmission and reception using the SDT method. The underlayer refers to Layer 2 (Layer 2, L2) or Layer 1 (Layer 1, L1).

Step 2: the UE determines that the SDT procedure failed.

Any manner or means may be employed as to how to determine the failure of the SDT process. In embodiment 1, as an example, it may be determined whether or not the SDT timer has expired, and if it is determined that the SDT timer has expired, the UE considers that the SDT procedure has failed.

Step 3: the UE saves the CEF information in the CEF report. Specifically, for example, one or more of the following information may be saved in the UE variable used to record the CEF report:

first information indicating that the failure procedure is for SDT; that is, the failure procedure is an SDT failure, or the failure is due to the expiration of an SDT timer. Still further, it may also be indicated that the failure procedure is for RA-SDT or CG-SDT.

And second information indicating that the failure occurred in a subsequent transmission stage of the SDT procedure. As previously described, the subsequent transmission refers to the transmission of a data packet that is not transmitted with the common control channel CCCH message during SDT, at which time the transmission (i.e., initial transmission) of the data packet that includes the CCCH message together with the user plane data has been successfully completed. The CCCH message is an RRCResumeRequest message. Preferably, the user plane data in the present disclosure is a data radio bearer (Data Radio Bearer, DRB). Alternatively, signaling radio bearers (Signalling Radio Bearer, SRB) are also included, such as SRB2. Preferably, the data packet in the present disclosure refers to a data packet of L2, such as a medium access control (Medium Access Control, MAC) protocol data unit (Protocol Data Unit, PDU) or a MAC service data unit (Service Data Unit, SDU).

In another form, the second information is indicative of a restart of the SDT timer.

In another form, the second information appears to indicate whether the failure occurred in an initial delivery phase or a subsequent delivery phase of the SDT process. For example, if the failure occurs during an initial transmission phase of the SDT procedure, the second information may indicate that the failure occurred during the initial transmission phase.

The UE may also store other existing failure information in the CEF report, such as location information, failed cell identity, measurement results of the failed cell or neighbor cells, etc.

Example 2

Embodiment 2 provides a CEF reporting method in an SDT scenario. Unlike embodiment 1, the UE does not record or save the corresponding CEF report every time the SDT procedure fails, but does record or save the corresponding CEF report when the SDT failure occurs in the initial transmission phase.

Hereinafter, embodiment 2 of the present disclosure will be described in detail. Fig. 4 is a schematic flow chart showing a connection establishment failure reporting method in embodiment 2 of the present invention. As shown in fig. 4, the connection establishment failure reporting method in embodiment 2 may include the following steps.

Step 1: the UE initiates an SDT procedure and starts an SDT timer.

The SDT timer is an RRC layer timer as described above, and is started along with the initiation of the transmission of the RRC resume request message rrcresmeequest, and when the SDT timer expires, the SDT procedure is considered to fail, the SDT procedure is ended, and the RRC idle state is entered, and operations for entering the RRC idle state, such as releasing radio resources and configuration thereof, are performed.

Step 2: the SDT timer times out before receiving the first resource scheduling command for scheduling uplink or downlink data.

In one implementation, the first resource scheduling command for scheduling uplink or downlink data is a first resource scheduling command for scheduling uplink or downlink data after RA is successfully completed in the RA-SDT process. It may also be or be included in a random access response (Random Access Response, RAR) for msgB indicating that two-step random access is successful, or the first resource scheduling command for scheduling uplink or downlink data is simultaneously scheduled with an msgB indicating that random access is successful or a contention resolution identity MAC control element. Preferably, the resource scheduling command refers to a PDCCH.

In one implementation, the first resource scheduling command for scheduling uplink or downlink data refers to a resource scheduling command for scheduling subsequent transmission, that is, the first resource scheduling command for scheduling uplink or downlink data after confirming that the initial transmission is successful. It is also possible to understand the first subsequent transmission, i.e. the first uplink PUSCH or physical downlink shared information (Physical Downlink Shared Channel, PDSCH) transmission after confirming the success of the initial transmission.

Step 3: the UE saves the relevant failure message in the UE variable for logging the CEF report. The failure information may be failure information defined in the existing mechanism or may be SDT-specific failure information (e.g., the first information and the second information as in embodiment 1).

Example 3

Embodiment 3 provides a CEF reporting method in an SDT scenario. In this embodiment, when an SDT failure that is not due to the SDT timer occurs, the UE also records or saves the corresponding SDT failure information.

Hereinafter, embodiment 3 of the present disclosure will be described in detail. Fig. 5 is a schematic flow chart showing a connection establishment failure reporting method in embodiment 3 of the present invention. As shown in fig. 5, the connection establishment failure reporting method in embodiment 3 may include the following steps.

Step 1: the UE initiates the SDT procedure. After initiating the SDT procedure, the UE instructs the bottom layer to perform data transmission and reception using the SDT method. The underlayer refers to Layer 2 (Layer 2, L2) or Layer 1 (Layer 1, L1).

Step 2: the UE determines that the SDT procedure failed due to the maximum number of radio link control (Radio Link Control, RLC) transmissions (retransmissions). In the SDT process, when the maximum number of RLC retransmission times of the UE is reached, the maximum number of retransmission times of the RLC layer is indicated to the RRC layer, and when the RRC layer receives the indication, the UE considers that the SDT process fails. This can also be expressed in the SDT process as when the SDT timer is running.

Step 3: the UE saves the relevant failure information in the UE variable for logging the CEF report.

The failure information may be failure information defined in the existing mechanism or may be SDT-specific failure information (e.g., the first information and the second information as in embodiment 1). In addition, the failure information may further include third information for indicating that the reason for the failure is due to the maximum number of RLC retransmissions being reached.

Example 4

Embodiment 4 provides a CEF reporting method in an SDT scenario. In the CG-SDT scene, when SDT failure occurs, the UE records and stores corresponding failure information, wherein random access information is not included.

Hereinafter, embodiment 4 of the present disclosure will be described in detail. Specifically, the connection establishment failure reporting method in example 4 may include the following steps.

Step 1: the UE initiates the SDT procedure and determines to initiate the SDT procedure using CG-SDT mode.

Step 2: the SDT process fails.

The UE may determine that the SDT procedure fails based on the SDT timer time out or based on the RLC retransmission number reaching the maximum number.

Step 3: the UE saves the relevant failure information in the UE variable for recording the CEF report, wherein the failure information does not contain random access procedure related information. Preferably, the random access information in the present disclosure refers to a perRAInfoList information element or a ra-information common information element. I.e. the random access information is recorded and contained in the failure information in case of failure of other connections than CG-SDT procedure. If the procedure is not for CG-SDT, the UE includes random access information in the CEF report.

Example 5

Embodiment 5 provides a CEF reporting method in an SDT scenario. Unlike embodiment 4, in this embodiment, the UE sets each information element in the random access information to an arbitrary value or a specific value in the CEF report corresponding to the CG-SDT.

Hereinafter, embodiment 5 of the present disclosure will be described in detail. Specifically, the connection establishment failure reporting method in example 5 may include the following steps.

Step 2: the SDT process fails.

Step 3: the UE saves the related failure information in the UE variable for recording the CEF report, wherein the random access related information in the failure information is set to an arbitrary value or a specific value. Optionally, when the random access information is set to an arbitrary value, the UE includes a fourth information in the failure information, where the fourth information may be used to indicate that the failure information corresponds to a CG-SDT procedure. When the random access information is set to a specific value, the network side can recognize that the random access information corresponds to a CG-SDT process when receiving the CEF report, so that it can be decided how to process the random access information, such as not using the random access information for network state analysis and network parameter setting.

Example 6

Embodiment 6 provides a CEF reporting method in an SDT scenario. When more than one random access procedure is performed in the SDT procedure, the UE determines to set random access information in the CEF report using information of the last random access procedure.

Hereinafter, example 6 of the present disclosure will be described in detail. Specifically, the connection establishment failure reporting method in example 6 may include the following steps.

Step 1: the UE initiates an SDT procedure, and transmits data using the SDT procedure.

Step 2: the SDT process fails.

Step 3: the UE saves the relevant failure information in the UE variable for logging the CEF report, and if more than one RA procedure is performed in the SDT procedure, it is preferable that the RA-related information in the failure information in the CEF report is for the most recent RA procedure in time. Alternatively, RA-related information in failure information in the CEF report is the RA procedure performed first in the SDT procedure; in RA-SDT, i.e. RA procedure for initial transmission.

Example 7

This embodiment provides a CEF reporting method in SDT scenarios. Unlike embodiment 6 in which the UE selects the last random access procedure information to set the random access information in the CEF report, in this embodiment, the random access information in the CEF report is a list, i.e., contains a plurality of items, each corresponding to one random access procedure.

Hereinafter, example 7 of the present disclosure will be described in detail. Specifically, the connection establishment failure reporting method in example 7 may include the following steps.

Step 2: the SDT process fails.

Step 3: the UE stores relevant failure information in a UE variable used for recording CEF reports, and if more than one RA process is executed in an SDT process, the failure information in the CEF report comprises a plurality of pieces of RA relevant information, and each piece of RA relevant information corresponds to one RA process. I.e., RA information corresponding to a plurality of RA procedures performed in the SDT procedure is contained and stored in the CEF report variable. Items of RA information in the list may be arranged in chronological order, such as the first item in the list corresponding to the RA process that occurs first in time in the SDT process, and so on. The plurality of items may be a list of a plurality of items perRAInfoList information elements or a list of a plurality of items ra-information common information elements.

In one implementation, the UE recording the CEF report corresponding to the SDT procedure for the above embodiment is performed when the UE is enabled with the CEF report corresponding to the SDT. The UE receives an RRC message (e.g., system information or RRC release message) containing fifth information from the network side, the fifth information being used to instruct/enable the UE to record the CEF report corresponding to the SDT procedure, that is, enable the UE to record and save the corresponding CEF report when the SDT procedure fails (e.g., the SDT timer expires). The UE variables described in the embodiments for recording and saving CEF reports refer to VarConnEstFailReport or VarConnEstFailReportList. The recorded failure information includes the measurement result of the failed cell, the location information, the measurement result of the neighbor cell, the number of connection failures, the random access information, the time elapsed from the occurrence of the connection failure event to the reporting, and the like, as described above. Obviously, the foregoing embodiment of the CEF reporting method corresponding to the SDT procedure stored in the UE further includes that the UE receives a ueinfomationrequest message from the network side, where the ueinfomationrequest message includes request indication information (such as a connEstFailReportReq information element) for requesting the UE to report the stored CEF report, and the UE includes the stored CEF information in the ueinfomationresponse message, and reports the same to the network side, where the UE includes SDT specific CEF information corresponding to the SDT procedure.

Example 8

The embodiment provides a failure information reporting method in an SDT scene. Unlike the foregoing embodiment, in which the UE reports the SDT failure information in the CEF report, the UE reports the SDT failure information to the network side in a radio link failure (Radio Link Failure, RLF) report.

Hereinafter, example 8 of the present disclosure will be described in detail. Specifically, the radio link failure reporting method in example 8 may include the following steps.

Step 1: the UE detects the SDT failure.

The SDT failure is as described in the previous embodiments, for example, due to the expiration of an SDT timer.

Step 2: the UE includes the SDT failure information in the RLF report.

The SDT failure information includes one or more of the aforementioned first through fourth information. In addition to this, the RLF report includes other contents supported in the RLF report of the existing R17 version, such as location information of the UE, measurement results of the failed cell, time elapsed between when the failure occurs and when the RLF report is delivered to the base station, and if the failure is due to a random access failure, information related to a random access procedure, which is described in the background section.

Optionally, the information of the SDT failure further includes fifth information recording a time elapsed from when the UE starts initiating the SDT procedure to when the SDT procedure fails.

In one implementation, the UE includes information of the SDT failure in the RLF report only if the SDT failure occurs in an initial transmission phase.

Fig. 6 is a block diagram illustrating a user device 60 according to an embodiment of the present disclosure. As shown in fig. 6, the user equipment 60 includes a processor 601 and a memory 602. The processor 601 may include, for example, a microprocessor, microcontroller, embedded processor, or the like. The memory 602 may include, for example, volatile memory (such as random access memory RAM), a Hard Disk Drive (HDD), non-volatile memory (such as flash memory), or other memory. The memory 602 has stored thereon program instructions. The instructions, when executed by the processor 601, may perform the random access reporting method described above in the user equipment described in detail in the present disclosure.

The program running on the apparatus according to the present disclosure may be a program for causing a computer to realize the functions of the embodiments of the present disclosure by controlling a Central Processing Unit (CPU). The program or information processed by the program may be temporarily stored in a volatile store such as a random access memory RAM, a Hard Disk Drive (HDD), a nonvolatile store such as a flash memory, or other memory system.

A program for realizing the functions of the embodiments of the present disclosure may be recorded on a computer-readable recording medium. The corresponding functions can be realized by causing a computer system to read programs recorded on the recording medium and execute the programs. The term "computer system" as used herein may be a computer system embedded in the device and may include an operating system or hardware (e.g., peripheral devices). The "computer-readable recording medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium in which a program is stored dynamically at a short time, or any other recording medium readable by a computer.

The various features or functional modules of the apparatus used in the embodiments described above may be implemented or performed by circuitry (e.g., single-chip or multi-chip integrated circuits). Circuits designed to perform the functions described herein may include a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The circuit may be a digital circuit or an analog circuit. Where new integrated circuit technologies are presented as an alternative to existing integrated circuits due to advances in semiconductor technology, one or more embodiments of the present disclosure may also be implemented using these new integrated circuit technologies.

Further, the present disclosure is not limited to the above-described embodiments. Although various examples of the embodiments have been described, the present disclosure is not limited thereto. Fixed or non-mobile electronic devices installed indoors or outdoors may be used as terminal devices or communication devices such as AV devices, kitchen devices, cleaning devices, air conditioners, office devices, vending machines, and other home appliances, etc.

As above, the embodiments of the present disclosure have been described in detail with reference to the accompanying drawings. However, the specific structure is not limited to the above-described embodiments, and the present disclosure also includes any design modifications without departing from the gist of the present disclosure. In addition, various modifications can be made to the present disclosure within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments are also included in the technical scope of the present disclosure. Further, the components having the same effects described in the above embodiments may be replaced with each other.

Claims

1. A connection establishment failure reporting method, comprising:

the User Equipment (UE) initiates a Small Data Transmission (SDT) process based on random access;

the UE judges that the SDT process fails; and

the UE saves the CEF information in a connection establishment failure CEF report,

The CEF information includes at least one of the following information: first information indicating that the failure procedure is for SDT; and second information indicating that the failure occurred in a subsequent transmission stage of the SDT procedure.

2. The connection establishment failure reporting method as claimed in claim 1, wherein,

the CEF information further comprises: location information, failed cell identity, measurement results of failed cells or neighbor cells.

3. The connection establishment failure reporting method according to claim 1 or 2, wherein,

and under the condition that an SDT timer started in the SDT process initiated by the UE is overtime, the UE judges that the SDT process fails.

4. The connection establishment failure reporting method as claimed in claim 3, wherein,

and under the condition that the SDT timer is overtime before the UE receives a first resource scheduling command for scheduling uplink or downlink data, the UE stores the CEF information in the CEF report.

5. The connection establishment failure reporting method according to claim 1 or 2, wherein,

and under the condition that the Radio Link Control (RLC) transmission reaches the maximum number of times, the UE judges that the SDT process fails.

6. The connection establishment failure reporting method according to claim 1 or 2, wherein,

When one or more random access RA procedures are performed in the SDT procedure, the CEF information includes RA information related to a latest RA procedure among the one or more RA procedures.

7. The connection establishment failure reporting method according to claim 1 or 2, wherein,

when one or more Random Access (RA) procedures are executed in the SDT procedure, the CEF information comprises RA information related to the one or more RA procedures.

8. A connection establishment failure reporting method, comprising:

the User Equipment (UE) initiates a Small Data Transmission (SDT) process based on a configuration permission mode;

the UE judges that the SDT process fails;

the UE saves CEF information in a connection establishment failure CEF report, and information related to random access in the CEF information is set to an arbitrary value or a specific value.

9. The connection establishment failure reporting method as recited in claim 8, wherein,

and judging that the SDT process fails when the SDT timer started in the process of initiating the SDT by the UE is overtime or when the Radio Link Control (RLC) transmission reaches the maximum number of times.

10. A user equipment, UE, comprising:

a processor; and

a memory storing instructions;

Wherein the instructions, when executed by the processor, perform the connection establishment failure reporting method according to any one of claims 1 to 9.