A communication method and device

Abstract

This application provides a communication method and device. In this method, the UE can perform an SDT procedure after meeting the conditions for initiating SDT, when the selected first feature or feature combination includes an SDT feature, and the random access resources configured by the base station contain a corresponding random access resource for the first feature or feature combination. Compared to the traditional approach where the UE initiates the SDT procedure as soon as the conditions for initiating SDT are met, the method provided in this application only initiates the SDT procedure if the selected feature or feature combination can achieve SDT. This avoids the phenomenon of mistakenly starting the first timer to initiate the SDT procedure when it cannot be achieved, thereby avoiding the adverse effects on power consumption and data transmission latency caused by mistakenly starting the first timer. Therefore, this method can guarantee a reduction in UE power consumption and data transmission latency.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent applications filed on December 23, 2021, with application number 202111587478.5 and entitled "A Communication Method, UE and Network Device", and filed on January 7, 2022, with application number 202210016639.3 and entitled "A Communication Method and Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of communication technology, and in particular to a communication method and device. Background Technology

[0004] In the 3rd Generation Partnership Project (3GPP) Release 17 (R17) study, mobile communication systems can support a variety of features, such as small data transmission (SDT), network slicing, low-capacity user equipment (UE) or reduced-capacity UE (redcap UE), and coverage enhancement (CE) UE.

[0005] It should be noted that the above features can be combined, which is called feature combination. For example, a redcap UE can perform SDT; a redcap UE can implement high-priority services corresponding to slicing; or a UE (or redcap UE) needs to transmit high-priority service data corresponding to slicing, which is small data, and needs to transmit this high-priority service data through SDT, etc.

[0006] For different features or feature combinations, the base station will allocate corresponding transmission resources to meet the transmission requirements or characteristics of different features or feature combinations. The specific process is as follows:

[0007] A UE in a non-connected state of radio resource control (RRC) (e.g., RRC idle state or RRC inactive state) can select a feature or feature combination after uplink data arrives and before data transmission. During random access, the UE can send signaling or data to the base station through the random access resources corresponding to the feature or feature combination to indicate to the base station the feature or feature combination currently selected by the UE, so that the base station can schedule transmission resources for the UE's current data transmission according to the feature or feature combination.

[0008] The random access resources corresponding to each feature or combination of features can be unique to that feature or combination of features and can differ from ordinary random access resources. For example, a mobile communication system can define the random access resources corresponding to a certain feature or combination of features as time resources and / or frequency resources that are separate from ordinary random access resources. It should be noted that although current communication technologies support multiple features or combinations of features, this does not limit each base station to providing random access resources corresponding to all types of features or combinations of features in each cell.

[0009] For UEs that currently support SDT, the RA-based SDT (RA-SDT) process can be implemented through the following steps:

[0010] When a UE has uplink data to be transmitted and meets the RA-SDT conditions, the UE will initiate an SDT procedure, including: restoring the SDT radio bearer (RB), starting a timer for SDT (e.g., an SDT failure detection timer), and initiating random access to implement SDT during the random access process.

[0011] However, due to various factors, the feature or feature combination selected by the UE may not include SDT, or although the feature or feature combination includes SDT, the base station may not have configured the random access resources for that feature or feature combination. This prevents the UE from using the random access resources corresponding to the SDT, thus preventing the UE from completing the SDT process. However, the UE has already started a timer for SDT. During the timer's execution, the UE will detect base station signaling or data and can only attempt the next RRC connection recovery process after the timeout. This not only increases the UE's power consumption but also adversely affects data transmission latency. Summary of the Invention

[0012] This application provides a communication method and device for reducing power consumption waste and data transmission latency in the case where the UE does not implement the SDT process.

[0013] In a first aspect, embodiments of this application provide a communication method that can be applied to a UE, specifically including the following steps:

[0014] When the UE is in the RRC inactive state, after determining that the conditions for initiating small packet transmission SDT are met, a first feature or feature combination is determined; when the first feature or feature combination includes the SDT feature, and the random access resources configured by the base station contain the random access resources corresponding to the first feature or feature combination, the SDT process is executed.

[0015] In this method, the UE can perform the SDT procedure after meeting the conditions for initiating SDT, specifically when the selected first feature or feature combination includes an SDT feature, and the base station's configured random access resources contain a corresponding random access resource for that first feature or feature combination. Compared to the traditional approach where the UE initiates the SDT procedure as soon as the conditions are met, the method provided in this application only initiates the SDT procedure if the selected feature or feature combination can achieve SDT. This avoids the phenomenon of mistakenly starting the first timer to initiate the SDT procedure when it cannot be achieved, thus preventing adverse effects on power consumption and data transmission latency caused by mistakenly starting the first timer, or the waste of air interface resources and / or signaling. Therefore, this method can guarantee reduced UE power consumption and data transmission latency, or reduce waste of air interface resources and / or signaling.

[0016] In one possible design, the UE may select the first feature or feature combination from at least one feature or feature combination supported by the UE and the base station, based on at least one or a combination of the following:

[0017] The selection rules are set, along with the characteristics configured by the base station or the characteristics combined with the corresponding random access resources, the transmission requirements of the UE (e.g., the characteristics or transmission delay of the currently arriving uplink data), the services performed by the UE, and the coverage status of the UE.

[0018] The selection rules can be configured by the base station through system information or other broadcast information, or specified by a protocol; this application does not limit this. For example, the selection rules may include the priority of features or feature combinations. The at least one feature or feature combination supported by the base station may be notified by the base station through system information, or determined by the UE based on the random access resources corresponding to the at least one feature or feature combination configured by the base station; this application does not limit this.

[0019] Optionally, the UE may also select a feature or feature combination by referring to its preferred features or feature combinations. For example, the UE (e.g., MAC layer or RRC layer, or other protocol layers) may determine its preferred features or feature combinations based on at least one feature or feature combination supported by the base station, or the random access resources corresponding to at least one feature or feature combination configured by the base station, or it may determine its preferred features or feature combinations based on at least one feature or feature combination supported by the UE, etc.

[0020] In one possible design, the UE can perform the SDT procedure through the following steps:

[0021] The SDT radio bearer RB is restored, and a first timer is started; wherein the first timer is used to detect whether the SDT process is successful, and the SDT RB is an RB used to perform SDT; and during the timing of the first timer, random access is initiated using the first feature or the feature combined with the corresponding random access resource, and target data is sent during the random access process; wherein the target data is carried in the SDT RB.

[0022] Optionally, the SDT RB can be configured by the base station. Optionally, the UE's RRC layer can perform the steps of restoring the SDT RB and starting the first timer, and the UE's MAC layer can perform the procedure of initiating random access.

[0023] In one possible design, the UE can determine a first characteristic or a combination of characteristics after determining that the conditions for initiating SDT are met: After the UE's MAC layer determines that the conditions for initiating SDT are met, the MAC layer determines the first characteristic or a combination of characteristics. In this case, before the UE executes the SDT procedure, the MAC layer can also send a first message to the UE's RRC layer, the first message indicating that the conditions for initiating SDT are met. Through this method, the MAC layer can notify the RRC layer that the conditions for initiating SDT are met, and the RRC layer can execute the SDT procedure.

[0024] In one possible design, the UE can determine a first feature or feature combination after determining that the conditions for initiating SDT are met through the following steps: after the UE's MAC layer determines that the conditions for initiating SDT are met, the MAC layer sends a second message to the RRC layer, the second message being used to indicate that the conditions for initiating SDT are met; the RRC layer selects the first feature or feature combination.

[0025] Using this method, the MAC layer can notify the RRC layer after the conditions for initiating SDT are met, so that the RRC layer can select the first feature or feature combination, and determine whether to execute the SDT process based on the selected feature or feature combination.

[0026] In one possible design, when the RRC layer determines that the first feature or feature combination includes the SDT feature, and the random access resources configured by the base station contain the random access resources corresponding to the first feature or feature combination, the RRC layer may also send a third indication to the MAC layer; after receiving the third message from the RRC layer, the MAC layer may initiate random access for SDT, and the third message is used to instruct the MAC layer to initiate random access for SDT.

[0027] Optionally, the RRC layer can also notify the MAC layer of the selected first feature or feature combination, or the random access resource corresponding to the first feature or feature combination. In this way, the MAC layer can use the first feature or feature combination and the corresponding random access resource to initiate SDT random access. For example, the RRC layer can notify the first feature or feature combination, or the random access resource corresponding to the first feature or feature combination, through the third message.

[0028] In one possible design, when the first feature or combination of features does not include the SDT feature, and / or the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or combination of features, the UE executes the RRC connection recovery procedure. Optionally, the UE can enter the connected state by executing the RRC connection recovery procedure.

[0029] Optionally, the RRC layer of the UE can execute the RRC connection recovery process, including: the RRC layer starting a second timer to detect whether the RRC connection recovery process is successful.

[0030] In one possible design, when the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the UE may further perform the following steps: initiating random access using the first random access resource configured by the base station; wherein, when the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the first random access resource is the same as the random access resource corresponding to the second feature or feature combination configured by the base station, or is a normal random access resource (different from the random access resources corresponding to all features or feature combinations configured by the base station); when the random access resources configured by the base station contain a random access resource corresponding to the first feature or feature combination, the first random access resource is the random access resource corresponding to the first feature or feature combination.

[0031] The second feature or feature combination can be reselected by the UE when it determines that there is no random access resource corresponding to the first feature or feature combination. Optionally, the priority of the second feature or feature combination reselected by the UE is lower than that of the previously selected first feature or feature combination. Optionally, when selecting the second feature or feature combination, the UE may not select a feature or feature combination that includes a feature or feature combination with a lower priority from the first feature or feature combination, but may select a feature or feature combination with a higher priority from the first feature or feature combination. Optionally, the first feature or feature combination includes features from the second feature or feature combination. For example, assuming that the priority of the slicing feature is lower than that of the redcap feature, the UE selects the first feature or feature combination as: redcap feature + slicing feature. When the UE determines that there is no random access resource corresponding to the first feature or feature combination, the UE may select the second feature or feature combination: redcap feature, and use the random access resource corresponding to the second feature or feature combination to initiate random access.

[0032] In a possible design, any characteristic or combination of characteristics includes at least one of the following:

[0033] SDT features, network slicing features, low-capability or reduced-capability UE redcap UE features, and coverage enhancement CE UE features.

[0034] Secondly, embodiments of this application provide a communication method that can be applied to a UE, and the method specifically includes the following steps:

[0035] When the UE is in the RRC inactive state, after determining that the conditions for initiating SDT are met, the SDT process is started and a first feature or feature combination is determined; when the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination, the SDT process is cancelled.

[0036] In this method, the UE can initiate an SDT (Service Deployment Technology) procedure when the conditions for initiating SDT are met. Then, if the first feature or feature combination selected by the UE does not include an SDT feature, and / or the random access resources configured by the base station do not contain a corresponding random access resource, the SDT procedure is cancelled. Because this method can promptly cancel the SDT procedure when the feature or feature combination selected by the UE cannot implement SDT, it can also quickly stop the first timer if it is mistakenly started, avoiding adverse effects on power consumption and data transmission latency caused by mistakenly starting the first timer, or problems such as wasted air interface resources and / or signaling. Therefore, this method can guarantee reduced UE power consumption and data transmission latency, or reduce wasted air interface resources and / or signaling.

[0037] In one possible design, the UE may select the first feature or feature combination from at least one feature or feature combination supported by the UE and the base station, based on at least one or a combination of the following:

[0038] The selection rules are set, along with the characteristics of the base station configuration or the characteristics combined with the corresponding random access resources, the transmission requirements of the UE (e.g., the characteristics or transmission delay of the currently arriving uplink data), the services of the UE, and the coverage status of the UE.

[0039] The selection rules can be configured by the base station through system information or other broadcast information, or specified by a protocol; this application does not limit this. For example, the selection rules may include the priority of features or feature combinations. The at least one feature or feature combination supported by the base station may be notified by the base station through system information, or determined by the UE based on the random access resources corresponding to the at least one feature or feature combination configured by the base station; this application does not limit this.

[0040] Optionally, the UE may also select a feature or feature combination by referring to its preferred features or feature combinations. For example, the UE (e.g., MAC layer or RRC layer, or other protocol layers) may determine its preferred features or feature combinations based on at least one feature or feature combination supported by the base station, or the random access resources corresponding to at least one feature or feature combination configured by the base station, or it may determine its preferred features or feature combinations based on at least one feature or feature combination supported by the UE, etc.

[0041] In one possible design, the UE can cancel the SDT process through the following steps:

[0042] After receiving a first message from the Media Access Control (MAC) layer, the RRC layer of the UE cancels the SDT procedure; wherein, the first message is used to notify the RRC layer to cancel the SDT procedure.

[0043] Optionally, the MAC layer can select a first feature or a combination of features. When the first feature or combination of features does not include the SDT feature, and / or the random access resources configured by the base station do not contain random access resources corresponding to the first feature or combination of features, the MAC layer sends a first message to the RRC layer.

[0044] In one possible design, the UE can initiate the SDT process through the following steps: the RRC layer restores the SDT radio bearer (RB) and starts a first timer; wherein the first timer is used to detect whether the SDT process is successful; wherein the SDT RB is an RB used to perform SDT. In this case, when the first feature or feature combination includes the SDT feature, and the random access resources configured by the base station contain the random access resources corresponding to the first feature or feature combination, during the timing of the first timer, the MAC layer can use the random access resources corresponding to the first feature or feature combination to initiate random access and send target data during the random access process; wherein the target data is carried in the SDT RB. Optionally, in this case, the RRC layer can cancel the SDT process through the following steps: the RRC layer stops the first timer, and / or the RRC layer suspends the SDT RB. Optionally, the SDTRB can be configured by the base station.

[0045] In one possible design, when the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the method further includes: the UE performing an RRC connection recovery procedure. Optionally, the UE's RRC layer can perform the RRC connection recovery procedure. For example, the RRC layer can start a second timer to detect whether the RRC connection recovery procedure is successful.

[0046] In one possible design, when the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the UE may further perform the following steps: initiating random access using the first random access resource configured by the base station; wherein, when the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the first random access resource is the same as the random access resource corresponding to the second feature or feature combination configured by the base station, or is a normal random access resource (different from the random access resources corresponding to all features or feature combinations configured by the base station); when the random access resources configured by the base station contain a random access resource corresponding to the first feature or feature combination, the first random access resource is the random access resource corresponding to the first feature or feature combination.

[0047] The second feature or feature combination can be reselected by the UE when it determines that there is no random access resource corresponding to the first feature or feature combination. Optionally, the priority of the second feature or feature combination reselected by the UE is lower than that of the previously selected first feature or feature combination. Optionally, when selecting the second feature or feature combination, the UE may not select a feature or feature combination that includes a feature or feature combination with a lower priority from the first feature or feature combination, but may select a feature or feature combination with a higher priority from the first feature or feature combination. Optionally, the first feature or feature combination includes features from the second feature or feature combination. For example, assuming that the priority of the slicing feature is lower than that of the redcap feature, the UE selects the first feature or feature combination as: redcap feature + slicing feature. When the UE determines that there is no random access resource corresponding to the first feature or feature combination, the UE may select the second feature or feature combination: redcap feature, and use the random access resource corresponding to the second feature or feature combination to initiate random access.

[0048] In a possible design, any characteristic or combination of characteristics includes at least one of the following:

[0049] SDT features, network slicing features, low-capability or reduced-capability UE redcap UE features, and coverage enhancement CE UE features.

[0050] Thirdly, embodiments of this application provide a communication device including a unit for performing the steps in any of the above aspects.

[0051] Fourthly, embodiments of this application provide a UE including at least one processing element and at least one storage element, wherein the at least one storage element is used to store programs and data, and the at least one processing element is used to execute the method provided in any aspect of this application.

[0052] Fifthly, embodiments of this application provide a communication system comprising a UE and a base station, wherein the UE is capable of implementing the methods provided in any of the above aspects.

[0053] Sixthly, embodiments of this application also provide a computer program that, when run on a computer, causes the computer to perform the methods provided in any of the above aspects.

[0054] In a seventh aspect, embodiments of this application also provide a computer-readable storage medium storing a computer program that, when executed by a computer, causes the computer to perform the method provided in any of the above aspects.

[0055] Eighthly, embodiments of this application also provide a chip for reading a computer program stored in a memory and executing the method provided in any of the above aspects.

[0056] Ninthly, embodiments of this application also provide a chip system including a processor for supporting a computer device in implementing the methods provided in any of the above aspects. In one possible design, the chip system further includes a memory for storing programs and data necessary for the computer device. The chip system may be composed of chips or may include chips and other discrete devices. Attached Figure Description

[0057] Figure 1 This application provides a schematic diagram of the architecture of a mobile communication system.

[0058] Figure 2 This application provides a schematic diagram of an RRC connection state transition.

[0059] Figure 3 A schematic diagram of the RB configuration for a base station provided in an embodiment of this application;

[0060] Figure 4 A schematic diagram of a four-step random access RA-SDT process is provided for an embodiment of this application;

[0061] Figure 5 A schematic diagram of a two-step random access RA-SDT process is provided for an embodiment of this application;

[0062] Figure 6A flowchart illustrating a communication method provided in an embodiment of this application;

[0063] Figure 7 A flowchart illustrating another communication method provided in an embodiment of this application;

[0064] Figure 8 A flowchart illustrating yet another communication method provided in an embodiment of this application;

[0065] Figure 9 A flowchart illustrating a communication method provided in an embodiment of this application;

[0066] Figure 10 A flowchart illustrating another communication method provided in an embodiment of this application;

[0067] Figure 11 A flowchart illustrating an example of a communication method provided in this application embodiment;

[0068] Figure 12 A flowchart illustrating another communication method example provided in the embodiments of this application;

[0069] Figure 13 A flowchart illustrating another example of a communication method provided in this application embodiment;

[0070] Figure 14 A structural diagram of a communication device provided in an embodiment of this application;

[0071] Figure 15 This is a structural diagram of a UE provided in an embodiment of this application. Detailed Implementation

[0072] This application provides a communication method and apparatus for reducing power consumption waste and data transmission latency in UEs that have not implemented the SDT (Software-Defined Transmission) procedure. The method and apparatus are based on the same technical concept. Since the principles underlying the problems solved by the method and apparatus are similar, their implementations can be mutually referenced, and repeated details will not be elaborated further.

[0073] The following explanations of some terms used in this application are provided to facilitate understanding by those skilled in the art.

[0074] 1) UE is a device that provides voice and / or data connectivity to users. UE can also be called terminal equipment, mobile station (MS), mobile terminal (MT), etc.

[0075] For example, the UE can be a handheld device with wireless connectivity, various vehicle-mounted devices, roadside units, etc. Currently, some examples of UEs include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), point-of-sale (POS) terminals, wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, various smart meters (smart water meters, smart electricity meters, smart gas meters), eLTE-DSA UEs, devices with integrated access and backhaul (IAB) capabilities, electronic control units (ECUs), in-vehicle computers, in-vehicle cruise control systems, and telematics boxes (T-BOXs).

[0076] 2) A base station is a device in a communication system that connects a UE to a wireless network. As a node in the radio access network, a base station can also be called a network device, a radio access network (RAN) node (or device), or an access point (AP).

[0077] Currently, some examples of base stations include: generation Node B (gNB), transmission reception point (TRP), evolved Node B (eNB), Node B (NB), access point (AP), home base station (e.g., home evolved Node B, or home Node B, HNB), or base band unit (BBU), Enterprise LTE Discrete Spectrum Aggregation (eLTE-DSA) base station, etc.

[0078] In another network architecture, a base station may include centralized unit (CU) nodes and distributed unit (DU) nodes. This architecture separates the protocol layers of the eNB in ​​a long term evolution (LTE) system. Some protocol layer functions are centrally controlled by the CU, while the remaining part or all of the protocol layer functions are distributed in the DU, which are centrally controlled by the CU.

[0079] 3) RRC Connection Status. In mobile communication systems, the RRC connection status of a UE includes three types: RRC connected state (RRC_connected, or simply connected state), RRC idle state (RRC_idle, or simply idle state), and RRC inactive state (RRC_inactive, or simply inactive state).

[0080] When the UE is in idle state, the RRC connection between the UE and the base station is disconnected, and the base station and the UE no longer save the UE context information. The UE can receive broadcast information (such as system information) and paging messages sent by the base station.

[0081] When the UE is in an inactive state, the RRC connection between the UE and the base station is disconnected, but the base station and the UE continue to save the UE's context information. When the UE enters the connected state from the inactive state, the base station and the UE can quickly restore the RRC connection between the UE and the base station based on the saved UE context information, enabling the UE to quickly return to the connected state.

[0082] When the UE is in connected state, there is an RRC connection between the UE and the base station, and the two can communicate based on the RRC connection.

[0083] 4) Small data packets: Data packets whose size is less than the set small data packet threshold. For example, small data packets may include, but are not limited to, the following types of data: instant messages from various communication applications (APPs), APP heartbeat packets or push messages, and various periodic data (including: heartbeat packets, monitoring data, meter readings, etc.) sent by wearable devices, industrial wireless communication devices, or various smart meters.

[0084] 5) Features or combinations of features, which are concepts derived for UE data transmission. Examples of features currently include: SDT feature, slicing feature, redcap UE feature, CE UE feature, etc. It should be noted that the above four features do not constitute a limitation on features, and the solution provided in this application can also be applied to other features proposed in the future.

[0085] For example, a UE with CE UE characteristics can be a UE in a weak coverage area, such as at the cell edge, or with poor signal quality. In this case, the UE can indicate to the base station that the current UE has poor coverage through random access resources, so that the base station can schedule multiple repeated transmission resources for the UE.

[0086] The SDT characteristic is: if the data arriving at a UE in an inactive state meets the SDT conditions, the UE can transmit small packet data in the inactive state without entering the RRC connected state. The resources used by the UE are those for transmitting small packet data, for example, the UE transmits small packet data through the RA-SDT or CG-SDT procedure.

[0087] The slicing feature allows a UE to indicate to the base station, via random access resources, that data related to a slicing service has arrived when data for that service is available. For example, if the data has a higher priority, the base station can prioritize processing that data, or it can schedule service-specific transmission resources for that data. The slicing feature can include slicing services; for instance, it can include slicing groups, where each slicing group can contain at least one slicing service.

[0088] The characteristics of a redcap UE are as follows: redcap UEs have lower bandwidth capabilities. When a redcap UE has data transmission requirements, it can indicate to the base station that the current UE is a redcap UE through random access resources. In this way, the base station can schedule available transmission resources for the redcap UE, such as transmission resources within the bandwidth available to the redcap UE.

[0089] Any two or more features can be combined; this is called feature combination. For example, a redcap UE can perform SDT (Slicing Technology), meaning the UE supports both redcap UE features and SDT features. Another example is that a base station can support SDT features, slicing features, and feature combinations (SDT features + slicing features). Yet another example is that the slicing feature can include services from both the first and second slicing groups; that is, a UE can perform services from both groups.

[0090] It should be noted that different UEs can support different features or combinations of features based on their own capabilities. Furthermore, in practical applications, when each UE has uplink data to transmit, it can select a feature or combination of features based on the actual situation, service requirements, and selection rules set by the base station or user. Similarly, different base stations support different features or combinations of features, and base stations can configure the features or combinations of features supported by the cells they manage.

[0091] In a mobile communication system, after a UE selects a feature or combination of features, it can indicate the selected feature or combination of features to the base station through transmission resources or other information, so that the base station can allocate corresponding transmission resources for the UE's current data transmission based on the feature or combination of features.

[0092] For example, during RRC connection resume, the UE can use the features or feature combinations configured by the base station to notify the base station of the selected feature or feature combination. For instance, during RA-SDT, when the UE initiates random access using the random access resources corresponding to the SDT feature, the base station can know that the UE needs to transmit uplink small packet data, thus enabling the UE to complete SDT in an inactive state and saving power. For slicing, when the UE executes a high-priority service corresponding to slicing, the UE can use the random access resources corresponding to the slicing feature to indicate to the base station that the UE is executing a high-priority service, thereby allocating corresponding transmission resources to the UE to ensure the transmission characteristics of the service. A redcap UE can use the random access resources corresponding to the redcap UE feature to indicate to the base station that the UE is a redcap UE, so the base station can schedule transmission resources on a suitable frequency band for the redcap UE. A CE UE can use the random access resources corresponding to the CE UE feature to indicate to the base station that the UE is a CE UE, so the base station can schedule transmission resources with multiple repetitions for the CE UE.

[0093] For example, in the SDT based on pre-configured grant (CG) resources (CG-SDT for short), the UE can use selected features or characteristics combined with the corresponding CG resources to transmit small packet data. In this way, the base station can determine the feature or feature combination selected by the UE based on at least one or a combination of the CG resources used by the UE to transmit small packet data, the logical channel carrying the small packet data, and the UE's inactive-radio network temporary identifier (I-RNTI) contained in the RRC request message transmitted with the small packet data.

[0094] 6) The RRC connection recovery process can be divided into two categories based on whether SDT can be implemented: RRC connection recovery process for SDT and RRC connection recovery process for non-SDT.

[0095] The RRC connection recovery procedure used for SDT is also known as the SDT procedure. In this procedure, the UE can implement SDT during the random access procedure (i.e., perform random access including SDT), that is, perform the RA-SDT procedure; the UE can also implement the SDT procedure through CG-SDT resources, that is, perform the CG-SDT procedure.

[0096] The RRC connection recovery procedure used for non-SDT is also known as the normal RRC connection recovery procedure. During this procedure, the UE can perform non-SDT random access.

[0097] It should be noted that the RRC connection recovery process is an RRC layer procedure; while CG-SDT, RA-SDT, and non-SDT random access procedures (including ordinary random access procedures) are all MAC layer procedures.

[0098] In the embodiments of this application, unless otherwise specified, the RRC connection recovery process involved is a normal RRC connection recovery process.

[0099] 7) "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the related objects before and after it are in an "or" relationship.

[0100] It should be noted that "multiple" in this application refers to two or more. "At least one" refers to one or more.

[0101] In addition, it should be understood that in the description of this application, the words "first" and "second" are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance or order.

[0102] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0103] Figure 1 The diagram illustrates the structure of a mobile communication system to which the method provided in this application is applicable. See also... Figure 1 As shown, the mobile communication system includes a base station and a user unit (UE).

[0104] A base station is a network-side entity capable of receiving and transmitting radio signals. It is responsible for providing radio access services to UEs within its coverage area, implementing physical layer functions, resource scheduling and radio resource management, Quality of Service (QoS) management, radio access control, and mobility management. Through base stations, UEs can access the core network and ultimately connect to the data network to realize their services.

[0105] Each base station is responsible for managing at least one cell. Each cell uses corresponding spectrum resources to provide access services to the UE.

[0106] A User Equipment (UE) is an entity on the user side capable of receiving and transmitting wireless signals. It can access the network through a cell managed by a base station. A UE can be various devices that provide voice and / or data connectivity to users, such as in-vehicle devices and smartphones. The UE and the base station can communicate via a Uu interface.

[0107] In mobile communication systems, the Uu interface protocol stack can be divided into non-access stratum (NAS) and access stratum (AS) depending on whether the signaling and process are related to access.

[0108] The NAS (Network Access Controller) is used to handle signaling or data transmission between the UE (User Equipment) and the core network. The transmitted content can include user information or control information, such as signaling related to service establishment or release, or mobility management information. The structure of NAS messages is independent of the AS (Application Server), but transmission needs to be implemented based on the AS protocol stack.

[0109] AS is the protocol used by the radio access network, i.e., the radio interface protocol, which includes a control plane protocol stack and a user plane protocol stack. The user plane protocol stack includes at least the following protocol layers: physical (PHY) layer, medium access control (MAC) layer, radio link control (RLC) layer, packet data convergence protocol (PDCP) layer, and service data adaptation protocol (SDAP) layer. The control plane protocol stack includes at least the following protocol layers: physical layer, MAC layer, RLC layer, PDCP layer, and RRC layer.

[0110] It should also be pointed out that, such as Figure 1 The mobile communication system shown is an example and does not limit the mobile communication systems to which the methods provided in this application are applicable. In summary, the embodiments of this application can also be applied to various types and standards of communication systems, such as: the 5th Generation (5G) communication system, the 6th Generation (6G) communication system, and other future evolutionary communication systems, Long Term Evolution (LTE) communication systems, Long Term Evolution-vehicle (LTE-V) systems, and other mobile communication systems.

[0111] exist Figure 1 In the mobile communication system shown, the UE's RRC connection states include: connected state, idle state, and inactive state. The UE performs different operations when in different RRC connection states, and can transition between different RRC connection states, such as... Figure 2 As shown:

[0112] 1. When a UE in idle state needs to transmit data, it initiates an RRC connection establishment procedure. During this procedure, the UE establishes an RRC connection with the base station by executing a random access procedure, and begins data transmission with the base station after entering the connected state. Specifically, during the random access procedure, the UE can send an RRC connection request message (e.g., an RRCSetupRequest message) to the base station and receive an RRC connection establishment message (e.g., an RRCSetup message) from the base station, thereby establishing an RRC connection.

[0113] 2. When the UE does not need to transmit data, the base station can release the UE through the RRC connection release process, so that the UE enters the idle state or inactive state.

[0114] For example, the base station sends an RRC connection release message with a suspend indication, such as RRC Release with suspend indication, causing the UE to enter an inactive state.

[0115] For example, the base station sends an RRC connection release message, such as an RRC Release message, to put the UE into an idle state.

[0116] 3. A UE in an inactive state can return to the connected state through the RRC connection resume procedure. During the RRC connection resume process, the UE can restore the RRC connection with the base station by executing a random access procedure and can begin data transmission with the base station after entering the connected state. Specifically, during the random access procedure, the UE can send an RRC connection resume request message (e.g., an RRCResumeRequest message) to the base station and receive an RRC connection resume message (e.g., an RRCResume message) from the base station, thereby restoring the RRC connection. Alternatively, the base station can release the UE through the RRC connection release procedure, putting it into the idle state.

[0117] A UE in an inactive state generally does not support data transmission; that is, the UE needs to re-establish the RRC connection and enter the connected state before it can transmit data. However, in some scenarios, the amount of data packets that an inactive UE needs to transmit may be very small (i.e., small data), even less than the amount of signaling data required for the UE to re-enter the connected state. To avoid unnecessary signaling overhead and power consumption, researchers in the field have studied small data transmission (SDT) mechanisms. For example, in the 3rd Generation Partnership Project (3GPP) Release 17 (R17), the inactive state SDT scheme is currently being standardized.

[0118] The SDT mechanism mainly includes the SDT scheme based on random access (RA) (referred to as RA-SDT) and the SDT scheme based on pre-configured grant (CG) resources (referred to as CG-SDT).

[0119] In the RA-SDT scheme, the random access configuration, including the RA-SDT configuration, is provided in the common control signaling (such as system information) sent by the base station. Each time the UE selects a new cell, it must read the common control signaling of that cell.

[0120] In the CG-SDT scheme, CG-SDT resources are sent to the UE by the base station through dedicated control signaling, and the CG-SDT resources are different for different cells.

[0121] It should be noted that the UE can initiate an SDT procedure not only when all data arrives. The base station first configures a radio bearer (RB) for the UE to perform SDT. This RB is used to carry and transmit small packet data (i.e., SDT data), and in this embodiment, it can be simply referred to as an SDT RB. The SDT RB includes at least one data radio bearer (DRB) and / or at least one signaling radio bearer (SRB). Only data carried on these SDT RBs can be transmitted through the SDT procedure. The UE cannot initiate an SDT procedure when data arrives on non-SDT RBs. Each RB consists of a PDCP, an RLC, and a logical channel (LCH). The RB is mainly used to carry data or signaling during data transmission. Figure 3 As shown, the UE can initiate the SDT procedure only when data arrives on RB1 or RB2, but the UE cannot initiate the SDT procedure when data arrives on RB3.

[0122] The RA-SDT scheme provided in the embodiments of this application will be described in detail below.

[0123] First, let's give a brief introduction to random access:

[0124] The base station sends the random access resources of the current cell to the UE through system information, such as the random access preamble, or the time-frequency resources for transmitting the random access preamble, i.e., the random access occasion (RO). Existing RA procedures are mainly divided into two types: four-step random access (4-step RA) and two-step random access (2-step RA). The base station may configure both four-step and two-step random access resources for the UE simultaneously, or it may configure only one of them. If the base station configures both types of random access resources for the UE, when the UE is not configured with contention-free random access (CFRA) resources, the UE will autonomously choose which type of random access to initiate based on the relationship between its current Reference Signal Receiving Power (RSRP) measurement and the RSRP threshold configured by the base station through system information.

[0125] The RA-SDT process in this application embodiment also includes two cases: four-step random access and two-step random access. The UE can obtain the RA-SDT random access resource from the system information broadcast by the base station, and select which type of random access to initiate based on the random access resource or the UE's current RSRP value.

[0126] See below. Figure 4 The process of RA-SDT using the four-step random access method is explained below:

[0127] S401: The UE sends message 1 (MSG1) to the base station. The MSG1 contains a random access preamble, which the UE uses to notify the base station of its random access request.

[0128] In some embodiments, the base station can determine that the UE's intention in sending the current random access preamble is to initiate SDT (Simultaneous Local Access Distance). In other words, the UE can send the random access preamble using the random access resources corresponding to the SDT feature configured by the base station to notify the base station of its SDT intention, thereby enabling the base station to prepare to receive small packet data. Optionally, the random access resources corresponding to the SDT feature may include: the random access preamble corresponding to the SDT feature configured by the base station, or the random access timing corresponding to the SDT feature configured by the base station, etc.

[0129] S402: In response to the random access preamble, the base station sends a random access response (RAR) (also known as message2, MSG2) to the UE.

[0130] After sending MSG1, the UE starts the RAR time window and listens for RARs sent by the base station within the RAR time window. If no RAR is received within the RAR time window, it means that the random access has failed and the UE will re-initiate the random access procedure.

[0131] In addition, compared to the ordinary four-step random access procedure, if the base station obtains the UE's intention to initiate SDT in S401, the base station can allocate a larger uplink grant (UL grant) resource for the message 3 (MSG3) sent by the UE, so that the UE can send small packet data in MSG3.

[0132] S403: Based on RAR scheduling, the UE sends MSG3 to the base station. MSG3 carries uplink small packet data. Additionally, MSG3 also carries an RRC request message, such as an RRCResumeRequest message, used to request the resumption of the RRC connection or to initiate an SDT procedure.

[0133] The RRC request message may contain information such as the UE's identifier. The UE's identifier may be a unique identifier assigned to the UE by the core network, or the UE's I-RNTI, etc.

[0134] In some embodiments, the base station may not be able to ascertain the UE's SDT intent through the random access resources used by the UE in S401. In this case, the UE can carry a buffer status report (BSR) in this step, allowing the base station to indirectly ascertain the UE's SDT intent. For example, the random access resources configured by the base station may not include resources dedicated to SDT, but the base station indicates support for SDT in the system information. In this case, the UE can initiate random access using non-SDT-dedicated random access resources, but the UE can send a BSR to the base station in MSG3, allowing the base station to know that the UE currently has small data packets waiting to be transmitted.

[0135] S404: The base station sends a UE contention resolution message (i.e., message 4 (MSG4)) to the UE.

[0136] MSG4 includes a contention resolution MAC control element (CE) (i.e., UE contentionresolution Identity MAC CE). After receiving message 4, the UE can determine whether the UE contentionresolution Identity MAC CE is consistent with MSG3; if they are consistent, the UE considers the random access procedure to be successful.

[0137] S405: In response to the RRC request message in MSG3, the base station can also send an RRC response message to the UE, such as an RRC Response message. This RRC Response message may carry the next-hop chaining count (NCC) used by the UE for the encrypted packet data when it next initiates the SDT procedure.

[0138] The UE can be notified of the success of this SDT process through the RRC response message. Alternatively, the UE can remain in an inactive state.

[0139] It should be noted that when the base station has downlink data, it can also send it to the UE in S405, such as downlink small packet data.

[0140] In some embodiments, the base station may send the messages in S404 and S405 to the UE at the same time, for example, when the UE has no other uplink small packet data after sending uplink small packet data in MSG3.

[0141] See below. Figure 5 The process of RA-SDT using a two-step random access method is explained.

[0142] S501: The UE sends an MSGA to the base station. The MSGA contains... Figure 4 The MSG1 and MSG3 components of the four-step random access method shown refer to the random access preamble, the RRC request message, and the uplink small packet data. For example, the RRC request message is an RRCResumeRequest message, used to request the restoration of the RRC connection or to initiate an SDT procedure.

[0143] The transmission resources used by the UE to send the MSGA can be obtained from the system information broadcast by the base station.

[0144] Similar to S401, in some embodiments, the base station can know that the UE's intention in sending the current random access preamble is that the UE wants to initiate SDT. That is, the UE can send the random access preamble by using the random access resources corresponding to the SDT configured by the base station to notify the base station of the UE's SDT intention, thereby enabling the base station to prepare to receive small packet data.

[0145] In some embodiments, the base station may not be able to ascertain the UE's SDT intent through the random access resources used by the UE in S501. In this case, the UE can carry a buffer status report (BSR) in this step, allowing the base station to indirectly ascertain the UE's SDT intent. For example, the random access resources configured by the base station may not include resources dedicated to SDT, but the base station indicates support for SDT in the system information. In this case, the UE can initiate random access using non-SDT-dedicated random access resources, but the UE can send a BSR to the base station in the MSGA, allowing the base station to know that the UE currently has small data packets waiting to be transmitted.

[0146] S502: The base station sends MSGB to the UE.

[0147] The MSGB may include any of the following: fallback RAR, backoff indication, or success RAR. When the MSGB includes a success RAR, the success RAR includes a contention resolution identifier, and the UE considers the random access procedure successful. When the MSGB includes a fallback RAR, the UE will fall back to the four-step random access method and send MSG3 carrying uplink small packet data to the base station.

[0148] S503: In response to the RRC request message in the MSGA, the base station can also send an RRC response message to the UE, such as an RRC Resume message. This RRC response message may carry an NCC for use by the UE when it initiates the next SDT procedure.

[0149] The UE can be notified of the success of this SDT process through the RRC response message. Alternatively, the UE can remain in an inactive state.

[0150] It should be noted that when the base station has downlink data, it can also send it to the UE in S503, such as downlink small packet data.

[0151] In some embodiments, the base station may send the messages in S502 and S503 to the UE at the same time, for example, when the UE has no other uplink small packet data after sending uplink small packet data in the MSGA.

[0152] It should be noted that in practical applications, when the UE initiates, such as Figure 4 or Figure 5 After the RA-SDT process shown, it may not be possible to transmit all the data to be transmitted by sending MSG3 or MSGA once.

[0153] For example, if a UE initiates a RA-SDT procedure for an instant message, in a four-step random access RA-SDT procedure, the UL grant indicated by the base station in the RAR cannot accommodate all the data of the instant message; or, in a two-step random access RA-SDT procedure, the target transmission resource selected by the UE from the transmission resources broadcast by the base station cannot accommodate all the data of the instant message. In this case, the UE can continue to transmit the remaining data of the instant message through a subsequent transmission.

[0154] For example, the service currently being performed by the UE will continuously generate multiple data packets, each of which is a small data packet. When the UE initiates RA-SDT, after the UE transmits one or more small data packets via MSG3 / MSGA, new small data packets arrive. At this time, the UE can continue to transmit the subsequently generated small data packets through subsequent transmissions.

[0155] like Figure 4 or Figure 5 As shown, the UE can complete the conflict resolution (e.g.) Figure 4 As shown, after transmitting MSG4 or Figure 5 As shown in the diagram (after transmitting MSGB), the UE uses the base station to dynamically schedule uplink resources for subsequent transmissions.

[0156] The CG-SDT scheme provided in this application embodiment is briefly described below: During the SDT process, the UE can use the CG-SDT resources preset by the base station to send an RRC request message and small packet data to the base station; then, it receives an RRC response message sent by the base station. The UE can know that the SDT process was successful through this RRC response message. For example, the RRC request message can be an RRCResumeRequest message, used to request the restoration of the RRC connection, or used to initiate the SDT process. The RRC response message can be an RRCResume message.

[0157] It should be noted that based on the different characteristics and usage conditions of RA-SDT and CG-SDT, UEs can use different SDT schemes in different application scenarios. Since the transmission resources for CG-SDT are configured by the base station for a specific UE and issued under dedicated control signaling, in order to ensure the transmission efficiency of that UE, the base station can also adjust the modulation and coding scheme (MCS) and other physical layer or channel parameters (e.g., Physical uplink shared channel (PUSCH)) to suit the radio conditions of that UE. Therefore, when a UE supports both RA-SDT and CG-SDT, CG-SDT is preferred for transmitting small packet data. The specific process of the UE initiating SDT is as follows:

[0158] When a UE in an inactive state has data to be transmitted, the UE will determine whether the conditions for initiating SDT are met, specifically including:

[0159] The UE's RRC layer determines whether the following first SDT conditions are met: a) a higher layer of the RRC layer (e.g., the NAS layer) requests the restoration of the RRC connection; b) the UE supports SDT; c) the base station or the cell where the UE is located supports SDT (e.g., the base station broadcasts SDT-related parameters within the current cell); d) the currently arriving data to be transmitted is data carried on an SDT RB; and e) a message indicating that the conditions for initiating SDT are met is received from the UE's MAC layer. If the RRC layer determines that the first SDT conditions are met, it initiates the SDT procedure; otherwise, it performs a normal RRC connection restoration procedure to restore the UE's RRC connection.

[0160] Optionally, the RRC layer may first determine whether the ad condition in the first SDT condition is met, and if so, instruct the MAC layer to determine whether the second SDT condition is met; or the RRC layer may first instruct the MAC layer to determine whether the second SDT condition is met, and then simultaneously determine whether the first SDT condition is met.

[0161] The MAC layer determines whether the following second SDT conditions are met: the amount of uplink data to be transmitted is less than or equal to a set small packet data threshold; and the UE's current RSRP is greater than a set first RSRP threshold. If the second SDT conditions are not met, the MAC layer notifies the RRC layer that the conditions for initiating SDT are not met. If the second SDT conditions are met, the MAC layer continues to select a carrier (e.g., a supplementary uplink (SUL) carrier or a normal uplink (NUL) carrier) and determines the available SDT schemes on that carrier.

[0162] The MAC layer first determines whether the CG-SDT conditions are met (i.e., whether the CG-SDT is available). For example, the CG-SDT conditions may include: the carrier selected by the MAC layer is configured with CG-SDT resources, and the CG-SDT resources are valid; at least one synchronization signal block (SSB) has an RSRP higher than a set second RSRP threshold.

[0163] If the MAC layer determines that the CG-SDT conditions are met, the MAC layer notifies the RRC layer that the conditions for initiating SDT are met, and the MAC layer initiates the CG-SDT process on the selected carrier.

[0164] If the MAC layer determines that the CG-SDT condition is not met, the MAC layer continues to determine whether the RA-SDT condition is met (i.e., whether RA-SDT is available). For example, the RA-SDT condition may include whether the carrier selected by the MAC layer is configured with resources available for RA-SDT (e.g., random access resources corresponding to SDT).

[0165] If the MAC layer determines that the RA-SDT conditions are met, the MAC layer notifies the RRC layer that the conditions for initiating SDT are met, and the MAC layer initiates the RA-SDT procedure on the selected carrier.

[0166] If the MAC layer determines that the RA-SDT conditions are not met, the MAC layer notifies the RRC layer that the conditions for initiating SDT are not met.

[0167] Based on the above UE-initiated SDT process, when the UE's MAC layer determines that the second SDT condition is met and RA-SDT is available, it will notify the RRC layer that the SDT initiation condition is met, initiate random access, and implement SDT during the random access process. Upon receiving this notification, the RRC layer initiates the SDT process, which includes: the RRC layer restoring the SDT RB and starting a first timer for timing the SDT process. This first timer is also known as the SDT failure detection timer.

[0168] As can be seen from the above introduction to features or feature combinations, mobile communication systems support not only SDT (Special Features Dependency Theory) but also other features and feature combinations. Furthermore, before data transmission, the UE needs to select a feature or feature combination and initiate random access using the corresponding random access resource to notify the base station of the selected feature or feature combination.

[0169] However, because the MAC layer can select features or feature combinations based on various factors (selection rules specified by the base station or protocol, or features or feature combinations supported by the UE, etc.), the features or feature combinations selected by the UE may not include SDT. Furthermore, even if the features or feature combinations selected by the UE include SDT, the random access resources configured by the base station may not contain the corresponding random access resources. All of these situations will cause the MAC layer to fail to implement the RA-SDT procedure, at which point the UE will fall back to the normal RRC connection recovery procedure. However, the UE's RRC layer has already started the first timer. During the timing of this first timer, the UE will detect base station signaling or data, and can only attempt the next RRC connection recovery procedure after the first timer expires. Because the UE started an incorrect timer, this not only increases the UE's power consumption but also adversely affects data transmission latency.

[0170] It should be noted that in some embodiments, the duration of the first timer may be longer than the duration of the second timer (e.g., T319) used for timing the normal RRC connection recovery process. This results in a longer timer duration used by the UE during the normal RRC connection recovery process, further negatively impacting UE power saving and data transmission latency. For example, if the UE uses the first timer when it has not actually initiated the SDT process, after the UE transmits the RRC request message, if the base station does not send an RRC response message to the UE, the UE needs to wait for the duration of the first timer. Since the duration of the first timer is longer than that of the second timer, this increases the UE's monitoring time, which is detrimental to UE power saving. Furthermore, if the UE needs to send data at this time, the UE needs to wait for the first timer to expire before initiating the RRC connection recovery process again. Since the duration of the first timer is longer than that of the second timer, this affects the latency of the UE's next data transmission.

[0171] In other embodiments, the duration of the first timer may be shorter than the duration of the second timer (e.g., T319) used for timing the normal RRC connection recovery process. This results in the UE using a shorter timer duration during the RRC connection recovery process. Since the base station determines how to send the RRC response message to the UE based on the duration of the second timer, the UE may no longer be listening for the RRC response message sent by the base station when the base station sends it. For example, the UE may be preparing to initiate the next RRC connection recovery process, leading to a waste of air interface resources and / or signaling.

[0172] For example, a redcap UE currently has uplink data. The UE determines that the first SDT condition is met and that RA-SDT is available, so the UE restores the SDT RB and starts the first timer. However, if the UE ultimately selects a redcap feature or a combination of features, and the base station does not broadcast available resources for the combination of redcap and SDT features, then the UE cannot continue executing the RRC connection recovery procedure corresponding to the SDT feature. Instead, it needs to perform a normal RRC connection recovery procedure through the random access procedure corresponding to the redcap feature to restore the UE's RRC connection before transmitting the uplink data. Therefore, the UE does not actually execute the SDT procedure, and the SDT RB restored and the first timer started for the SDT procedure are not applicable to subsequent processes.

[0173] For example, if a UE has uplink data to transmit during the execution of a service corresponding to a certain slicing, and the UE determines that the first SDT condition is met and that RA-SDT is available, the UE restores the SDT RB and starts the first timer. Before the data transmission, the UE selects the first feature or feature combination as the slicing feature + SDT feature. However, when selecting random access resources, the UE determines that the base station has not configured the random access resources corresponding to the slicing feature + SDT feature, but only the random access resources corresponding to the slicing feature. Therefore, the UE can initiate random access using the random access resources corresponding to the second feature or feature combination (i.e., the slicing feature) and execute a normal RRC connection recovery procedure to restore the UE's RRC connection before transmitting the uplink data. Similarly, the UE does not actually execute the SDT procedure, and the SDT RB restored and the first timer started for the SDT procedure are not applicable to subsequent procedures.

[0174] It should be noted that the "UE selects a feature or feature combination" mentioned in the description of the embodiments of this application can be executed by the UE after restoring the SDT RB and starting the first timer, but before selecting random access resources; or it can be executed by the UE when selecting random access resources. The description of the various embodiments of this application does not constitute a limitation on this. For example, the UE can learn about the features or feature combinations supported by the current cell / base station based on at least one feature or feature combination corresponding to the random access resources in the received system information.

[0175] Before introducing the embodiments of this application, the first timer and the second timer involved in the various embodiments of this application will be introduced first.

[0176] The first timer is started when the UE initiates the SDT procedure, for example, by the UE's RRC layer, to detect whether the SDT procedure is successful. Therefore, the first timer is also called the SDT failure detection timer. Since the SDT procedure is initiated when the UE is in an inactive state, the UE will perform the RRC connection recovery procedure during the SDT procedure. That is, when the UE transmits an RRC request message (e.g., an RRC Resume Request message) to the base station, the UE starts the first timer, i.e., the first timer begins counting. If the UE receives an RRC response message (e.g., an RRC Resume Message) from the base station during the first timer's counting process, the UE can stop the first timer and determine that the SDT procedure was successful. If the first timer times out, the UE can determine that the SDT procedure failed, and the UE can enter an idle state.

[0177] The second timer is started when the UE initiates a normal RRC connection recovery process, such as when the UE's RRC layer starts it, to detect whether the RRC connection recovery process is successful. This timer is also known as T319. When the UE transmits an RRC request message (e.g., an RRCResumeRequest message) to the base station, the UE starts the second timer, i.e., the second timer begins counting. If, during the second timer's counting process, the UE receives an RRC response message from the base station (e.g., an RRCResume message, an RRCSetup message, an RRCResume message, or an RRCResume with suspend indication message, etc.), the UE can stop the first timer. When the RRC response message from the base station is an RRCResume message, the UE determines that the current RRC connection recovery process is successful, and the UE can restore the RRC connection; when the RRC response message from the base station is an RRCResume message, or an RRCResume with suspend indication message, etc., the UE determines that the current RRC connection recovery process has failed, and the UE cannot enter the RRC connected state. If the second timer times out, the UE can determine that the current RRC connection recovery process has failed, and the UE cannot recover the RRC connection.

[0178] In some embodiments, the UE can determine a feature or feature combination in the following way: Data arrives, the UE knows its current UE type, and the features or feature combinations supported by itself and the base station. The UE can then determine the conditions corresponding to the feature. For example, the UE can determine whether the arriving data corresponds to the slicing feature, whether the arriving data meets the small packet data transmission conditions, and the current coverage status based on the current RSRP. Based on these factors, the UE can determine a first feature or feature combination. The UE can then determine whether the random access resources corresponding to the feature or feature combination broadcast by the base station include the random access resources corresponding to the first feature or feature combination. If they do, the UE currently selects the first feature or feature combination. If not, the UE needs to reselect a second feature or feature combination based on the set selection rules and determine whether the random access resources corresponding to the feature or feature combination broadcast by the base station include the random access resources corresponding to the second feature or feature combination. Finally, the UE can determine the selected feature or feature combination. In some embodiments, the UE can be replaced by a MAC layer or an RRC layer.

[0179] In cases where the UE has not implemented the SDT procedure, to avoid the adverse effects on UE power consumption and data transmission latency caused by starting an incorrect timer, embodiments of this application provide some communication methods. These methods can be applied to, for example... Figure 1 In the mobile communication system shown below, please refer to... Figures 6-8 The flowchart shown illustrates the method provided in this application embodiment in detail. It should be noted that this application embodiment uses UE support for both CG-SDT and RA-SDT SDT schemes as examples. The first SDT condition, second SDT condition, CG-SDT condition, and RA-SDT condition involved in this application embodiment all follow the concepts in the above-described UE-initiated SDT process, and will not be described in detail in the following embodiments. Furthermore, in this application embodiment, when the UE's RRC layer determines whether the first SDT condition (ae) is satisfied, it is assumed that condition ad is satisfied.

[0180] See below. Figure 6 The flowchart shown illustrates a communication method provided in an embodiment of this application. It should be noted that in this embodiment, the MAC layer of the UE performs a step of selecting features or a combination of features.

[0181] S601: When the UE has an uplink data transmission requirement, the UE's MAC layer determines whether the second SDT condition is met.

[0182] Optionally, when uplink data arrives at the RRC layer of the UE, the RRC layer instructs the MAC layer to determine whether the second SDT condition is satisfied, and simultaneously determines ad in the first SDT condition; or when uplink data arrives at the RRC layer, the RRC layer first determines ad in the first SDT condition, and when both conditions ad are satisfied, it instructs the MAC layer to determine whether the second SDT condition is satisfied.

[0183] When the MAC layer determines that the second SDT condition is not met, the UE executes steps S602-S603; when the MAC layer determines that the second SDT condition is met, the UE executes steps S604-S614.

[0184] S602: When the MAC layer determines that the second SDT condition is not met, the MAC layer sends a first message to the RRC layer, the first message being used to indicate that the condition for initiating SDT is not met.

[0185] S603: After the RRC layer receives the first message from the MAC layer, the UE performs a normal RRC connection recovery process, including S6031 and S6032.

[0186] S6031: The RRC layer starts the second timer (T319) to initiate a normal RRC connection recovery process.

[0187] The second timer is used to time the normal RRC connection recovery process.

[0188] S6032: During the timing of the second timer, the MAC layer performs non-SDT random access.

[0189] Optionally, in or before S6032, the MAC layer may select a feature or a combination of features. For example, the MAC layer may select a feature or a combination of features by, but is not limited to, at least one of the following:

[0190] The UE supports at least one feature or combination of features, the set selection rules, the base station supports at least one feature or combination of features, the random access resources corresponding to at least one feature or combination of features configured by the base station, the UE's transmission requirements (e.g., the characteristics or transmission delay of the currently arriving uplink data), the services performed by the UE, and the UE's current coverage status, etc.

[0191] The selection rules can be configured by the base station through system information or other broadcast information, or specified by a protocol; this application does not limit this. For example, the selection rules may include the priority of features or feature combinations. The at least one feature or feature combination supported by the base station may be notified by the base station through system information, or determined by the UE based on the random access resources corresponding to the at least one feature or feature combination configured by the base station; this application does not limit this.

[0192] Optionally, the MAC layer may also select a feature or feature combination by referring to the UE's preferred features or feature combinations. For example, the UE (e.g., the MAC layer or RRC layer, or other protocol layers) may determine its preferred features or feature combinations based on at least one feature or feature combination supported by the base station, or the random access resources corresponding to at least one feature or feature combination configured by the base station. It may also determine its preferred features or feature combinations based on at least one feature or feature combination supported by the UE, etc. For example, how to determine the preferred features or feature combinations can be referred to the above description of how to select features or feature combinations.

[0193] In one implementation, in order to ensure that the random access resources configured by the base station contain the characteristics or combinations of characteristics selected by the MAC layer, the MAC layer can select the characteristics or combinations of characteristics based on at least one characteristic or combination of characteristics configured by the base station (optionally, it can also combine other factors described above).

[0194] Optionally, in S6032, when the random access resources configured by the base station contain random access resources corresponding to a feature or feature combination selected by the MAC layer, the MAC layer uses this random access resource to initiate random access; when the random access resources configured by the base station do not contain random access resources corresponding to this feature or feature combination, the MAC layer can use ordinary random access resources (different from the random access resources corresponding to all features or feature combinations configured by the base station) to initiate random access; or when the random access resources configured by the base station do not contain random access resources corresponding to this feature or feature combination, the MAC layer can select another feature or feature combination and use the random access resource corresponding to this other feature or feature combination to initiate random access. Optionally, the priority of the feature or feature combination reselected by the MAC layer is lower than that of the previously selected feature or feature combination. Optionally, when reselecting a feature or feature combination, the MAC layer may not select a feature or feature combination with a lower priority from the previously selected feature or feature combination, but may select a feature or feature combination with a higher priority from the previously selected feature or feature combination. Optionally, the previously selected feature or feature combination may include the feature in the reselected feature or feature combination. For example, the MAC layer may select a first feature or feature combination: redcap feature + slicing feature. When the MAC layer determines that there is no random access resource corresponding to the first feature or feature combination, the MAC layer may select a second feature or feature combination: redcap feature, and use the random access resource corresponding to the second feature or feature combination to initiate random access.

[0195] After the UE restores its RRC connection with the base station by performing a normal RRC connection recovery process, the UE is able to send the uplink data to the base station.

[0196] S604: When the MAC layer determines that the second SDT condition is met, the MAC layer continues to determine whether the CG-SDT condition is met.

[0197] When the MAC layer determines that the CG-SDT condition is met, execute S605-S606; when the MAC layer determines that the CG-SDT condition is not met, execute S607-S614.

[0198] S605: When the MAC layer determines that the CG-SDT condition is met, the MAC layer sends a second message to the RRC layer. The second message indicates that the condition for initiating SDT is met. In some embodiments, the second message may also indicate that the CG-SDT condition is met (i.e., the CG-SDT scheme is available).

[0199] S606: After the RRC layer receives the second message from the MAC layer (assuming the RRC layer determines that the first SDT condition is met), the UE executes the SDT procedure (i.e., the RRC connection restoration procedure for SDT). During this procedure, the MAC layer executes the CG-SDT procedure.

[0200] In S606, the UE can execute the procedure using a traditional SDT process. Optionally, in this step, the RRC layer can restore the SDT RB and start a first timer to initiate the SDT process. The SDT RB is the RB used to execute the SDT. Optionally, the SDT RB can be configured by the base station.

[0201] During the timing of the first timer, the MAC layer can execute the CG-SDT procedure. Before transmitting data, the MAC layer can select a feature or a combination of features (the specific selection process can be found in the description in S6032), and then select an available CG-SDT resource from the CG-SDT resources configured by the base station. The selected CG-SDT resource is then used to transmit the uplink data (uplink small packet data) and the RRC request message carried on the SDT RB. For example, the RRC request message can be an RRCResumeRequest message, used to request the resumption of the RRC connection, or used to initiate an SDT procedure.

[0202] For example, if the incoming uplink data is data for a high-priority service corresponding to a slice, and the UE determines that the first SDT condition is met, the UE can transmit this uplink data through CG-SDT resources (optionally, it can also transmit an RRC request message). The base station can determine that the uplink data is small packet data through the CG-SDT resources, and identify that the currently transmitted data is service data for the service corresponding to the slice by using the identifier of the logical channel carrying the uplink data. Therefore, the base station can identify that the currently transmitted data is small packet data for the service corresponding to the slice by using the identifier of the logical channel carrying the uplink data and the CG-SDT resources. There is a correlation between the slice and the logical channel.

[0203] For example, if the incoming uplink data belongs to a redcap UE, and the redcap UE determines that the first SDT condition is met, then the redcap UE can transmit this uplink data through CG-SDT resources (optionally, it can also transmit an RRC request message). The base station can identify that the currently transmitted data is a small packet from the redcap UE through this CG-SDT resource. This can be understood as the base station specifically configuring available CG-SDT resources for the redcap UE due to its limited bandwidth capacity; or the base station can identify that the currently transmitted data is a small packet from the redcap UE through the I-RNTI of the redcap UE in the RRC request message.

[0204] For example, if the incoming uplink data is data for a high-priority service corresponding to a slice of a redcap UE, and the redcap UE determines that the first SDT condition is met, then the redcap UE can transmit this uplink data through CG-SDT resources (optionally, it can also transmit an RRC request message). The base station can identify that the currently transmitted data is a small packet of data belonging to the redcap UE through the CG-SDT resources or through the I-RNTI of the redcap UE in the RRC request message; and the base station can identify that the currently transmitted data is service data corresponding to the slice through the logical channel identifier carrying the uplink data. Therefore, the base station can identify that the currently transmitted data is small packet data of the slice service of the redcap UE.

[0205] In the embodiments of this application, the UE's choice to transmit small packet data of a certain feature or combination of features through CG-SDT resources can implicitly represent the UE to perform the selection of features or combination of features.

[0206] S607: When the MAC layer determines that the CG-SDT condition is not met, the MAC layer continues to determine whether the RA-SDT condition is met.

[0207] When the MAC layer determines that the RA-SDT condition is met, execute S608-S612; when the MAC layer determines that the RA-SDT condition is not met, execute S613-S614.

[0208] S608: When the MAC layer determines that the RA-SDT condition is met, the MAC layer selects a first characteristic or a combination of characteristics, and determines whether the first characteristic or the combination of characteristics satisfies the third SDT condition. The third SDT condition is used to determine whether the selected characteristic or combination of characteristics can achieve SDT.

[0209] In one implementation, similar to the description in S6032, the MAC layer may select the first feature or a combination of features based on multiple factors. For example, the MAC layer may select the first feature or a combination of features based on at least one or a combination of the following:

[0210] The UE supports at least one feature or combination of features, the set selection rules, the base station supports at least one feature or combination of features, the random access resources corresponding to the features or combination of features configured by the base station, the UE's transmission requirements (e.g., the characteristics or transmission delay of the currently arriving uplink data), the services performed by the UE, the UE's current coverage status, and the UE's preferred features or combination of features, etc.

[0211] The selection rules can be configured by the base station through system information or other broadcast information, or specified by a protocol; this application does not limit this. For example, the selection rules may include the priority of features or feature combinations. The at least one feature or feature combination supported by the base station may be notified by the base station through system information, or determined by the UE based on the random access resources corresponding to the at least one feature or feature combination configured by the base station; this application does not limit this.

[0212] For example, when the MAC layer selects a feature or feature combination based on the actual situation or requirements such as the transmission requirements of the UE and / or the services performed by the UE, the feature or feature combination may include the SDT feature. However, the random access resources configured by the base station may not necessarily contain the random access resources corresponding to the feature or feature combination.

[0213] For example, when the MAC layer selects a feature or feature combination based on at least one feature or feature combination supported by the base station and / or the set selection rules configured by the base station, the random access resources configured by the base station may include random access resources corresponding to the feature or feature combination, but the feature or feature combination may not necessarily include the SDT feature.

[0214] In summary, in this embodiment, since the first feature or feature combination selected by the MAC layer may or may not include the SDT feature, and the random access resources configured by the base station may or may not contain the random access resources corresponding to the first feature or feature combination, the third SDT condition in this embodiment includes: the selected feature or feature combination includes SDT, and the random access resources configured by the base station contain the random access resources corresponding to the selected feature or feature combination.

[0215] In another implementation, in order to ensure that the random access resources configured by the base station contain the characteristics or combinations of characteristics selected by the MAC layer, the MAC layer may select a first characteristic or combination of characteristics based on at least one characteristic or combination of characteristics configured by the base station (optionally, it may also combine other factors described above).

[0216] In this embodiment, the first feature or feature combination selected by the MAC layer may or may not include SDT. Therefore, the third SDT condition includes: the selected feature or feature combination includes SDT.

[0217] In another implementation, in order to ensure that the feature or feature combination selected by the MAC layer includes the SDT feature, the MAC layer may select the first feature or feature combination based on at least one of the UE’s transmission requirements, the service performed by the UE, and the UE’s current coverage status.

[0218] In this embodiment, the random access resources configured by the base station may or may not contain the random access resources corresponding to the first characteristic or combination of characteristics. Therefore, in this embodiment, the third SDT condition includes: the random access resources configured by the base station contain the random access resources corresponding to the selected characteristic or combination of characteristics.

[0219] When the MAC layer determines that the selected feature or feature combination does not satisfy the third SDT condition, the UE executes S609-S610; when the MAC layer determines that the selected feature or feature combination satisfies the third SDT condition, the UE executes S611-S612.

[0220] In one implementation, when the MAC layer determines that the currently selected first feature or feature combination does not meet the third SDT condition (for example, when there is no random access resource corresponding to the first feature or feature combination in the random access configured by the base station), the MAC layer may also re-execute S608, select a second feature or feature combination, determine whether the second feature or feature combination meets the third SDT condition, and perform subsequent processes for the second feature or feature combination.

[0221] Optionally, the second feature or feature combination has a lower priority than the first feature or feature combination. Optionally, when reselecting a feature or feature combination, the MAC layer may choose not to select a feature or feature combination with a lower priority from the previously selected feature or feature combination, but may choose a feature or feature combination with a higher priority from the previously selected feature or feature combination. Optionally, the first feature or feature combination includes features from the second feature or feature combination. For example, the first feature or feature combination includes: redcap UE feature + SDT feature. When the MAC layer determines that there is no random access resource corresponding to the first feature or feature combination, the MAC layer may select the second feature or feature combination: redcap UE feature, and in subsequent steps, use the random access resource corresponding to the second feature or feature combination to initiate random access.

[0222] S609: When the MAC layer determines that the third SDT condition is not met, the MAC layer sends a third message to the RRC layer, the third message being used to indicate that the condition for initiating SDT is not met.

[0223] S610: After the RRC layer receives the third message from the MAC layer, the UE performs a normal RRC connection recovery process, including S6101 and S6102.

[0224] S6101: Same as S6031 in S603.

[0225] S6102: During the timing of the second timer, the MAC layer performs non-SDT random access.

[0226] Similar to S6032, but with a difference: the MAC layer does not select a feature or feature combination in this step. In this step, when the random access resources configured by the base station contain a random access resource corresponding to the first feature or feature combination selected by the MAC layer, the MAC layer uses that random access resource to initiate random access; when the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the MAC layer can use ordinary random access resources (different from the random access resources corresponding to all features or feature combinations configured by the base station) to initiate random access, or use the random access resource corresponding to the second feature or feature combination to initiate random access.

[0227] S611: When the MAC layer determines that the third SDT condition is met, the MAC layer sends a fourth message to the RRC layer, the fourth message indicating that the condition for initiating SDT is met. Optionally, the fourth message may also indicate that the RA-SDT condition is met (i.e., the RA-SDT scheme is available).

[0228] S612: After the RRC layer receives the fourth message from the MAC layer (assuming the RRC layer determines that the first SDT condition is met), the UE performs the SDT procedure (i.e., the RRC connection recovery procedure for SDT), including S6121 and S6122.

[0229] S6121: The RRC layer restores the SDT RB and starts the first timer to initiate the SDT process.

[0230] The SDT RB is the RB used to perform SDT, such as Figure 3 As shown. Optionally, the SDT RB can be configured for the base station.

[0231] S6122: During the timing of the first timer, the MAC layer executes the RA-SDT procedure (i.e., performs random access including SDT), that is, the MAC layer initiates random access and implements SDT during the random access process, including: the MAC layer initiates random access using selected features or features combined with corresponding random access resources (sending MSG1 or MSGA); and carries the uplink data in MSG3 or MSGA during the random access process. The uplink data is carried in the SDTRB.

[0232] The specific process of RA-SDT execution at the MAC layer described in S612 can be found in [reference needed]. Figure 4 or Figure 5 This will not be elaborated further here. Through S612, the UE can send uplink data to the base station during random access.

[0233] S613: When the MAC layer determines that the RA-SDT condition is not met, the MAC layer sends a fifth message to the RRC layer, the fifth message being used to indicate that the condition for initiating SDT is not met.

[0234] S614: Same as S603, that is, S6141-S6142 can be referred to the descriptions in S6031 and S6032, and will not be repeated here.

[0235] Figure 6The illustrated embodiment provides a communication method in which the UE's MAC layer, after determining that the second SDT condition is met and selecting a feature or feature combination, further determines whether the third SDT condition is met based on the selected feature or feature combination, and then notifies the RRC layer whether the result satisfies the conditions for initiating SDT. This method avoids the phenomenon where the RRC layer incorrectly starts the first timer when the MAC layer cannot implement the SDT process, thereby avoiding the adverse effects on power consumption and data transmission latency caused by incorrectly starting the first timer, or the problem of wasted air interface resources and / or signaling. Therefore, this method can guarantee reduced UE power consumption and data transmission latency, or reduce wasted air interface resources and / or signaling.

[0236] See below. Figure 7 The flowchart shown illustrates another communication method provided in this application embodiment. It should be noted that in this application embodiment, the UE's RRC layer performs the step of selecting features or a combination of features.

[0237] S701: When the UE has an uplink data transmission requirement, the UE's MAC layer determines whether the second SDT condition is met.

[0238] The timing of the MAC layer executing S701 can be referenced. Figure 6 The description in S601 of the illustrated embodiment will not be repeated here.

[0239] When the MAC layer determines that the second SDT condition is not met, the UE executes steps S702-S703; when the MAC layer determines that the second SDT condition is met, the UE executes steps S704-S714.

[0240] S702: When the MAC layer determines that the second SDT condition is not met, the MAC layer sends a first message to the RRC layer, the first message being used to indicate that the condition for initiating SDT is not met.

[0241] S703: After the RRC layer receives the first message from the MAC layer, the UE performs a normal RRC connection recovery process, including S7031 and S7032.

[0242] S7031: The RRC layer starts the second timer (T319) to initiate a normal RRC connection recovery process.

[0243] The second timer is used to time the normal RRC connection recovery process.

[0244] S7032: During the timing of the second timer, the MAC layer performs non-SDT random access.

[0245] Optionally, before the MAC layer executes S7032, the RRC layer may also select a feature or a combination of features. In this embodiment, the specific steps for the RRC layer to select a feature or a combination of features can be found in [reference needed]. Figure 6 The description of the MAC layer selection feature or feature combination in S6032 of the illustrated embodiment will not be repeated here.

[0246] In one implementation, after selecting a feature or feature combination, the RRC layer can further determine whether the random access resources configured by the base station contain a random access resource corresponding to the feature or feature combination. When the RRC layer determines that the random access resources configured by the base station contain a random access resource corresponding to the feature or feature combination, the RRC layer can notify the MAC layer of the random access resource or the feature or feature combination, so that the MAC layer can directly initiate random access based on the random access resource when executing S7032. When the RRC layer determines that the random access resources configured by the base station do not contain a random access resource corresponding to the feature or feature combination, the RRC layer can instruct the MAC layer to initiate ordinary random access, so that the MAC layer can directly select ordinary random access resources to initiate random access when executing S7032; or the RRC layer can reselect another feature or feature combination, so that the MAC layer can initiate random access based on the random access resource corresponding to the other feature or feature combination.

[0247] After the UE restores its RRC connection with the base station by performing a normal RRC connection recovery process, the UE is able to send the uplink data to the base station.

[0248] S704: When the MAC layer determines that the second SDT condition is met, the MAC layer continues to determine whether the CG-SDT condition is met.

[0249] When the MAC layer determines that the CG-SDT condition is met, execute S705-S706; when the MAC layer determines that the CG-SDT condition is not met, execute S707-S715.

[0250] S705: When the MAC layer determines that the CG-SDT condition is met, the MAC layer sends a second message to the RRC layer. The second message indicates that the condition for initiating SDT is met. Optionally, the second message may also indicate that the CG-SDT condition is met (i.e., the CG-SDT scheme is available).

[0251] S706: After the RRC layer receives the second message from the MAC layer, (assuming the RRC layer determines that the first SDT condition is met), the UE executes the SDT procedure (i.e., the RRC connection recovery procedure for SDT). The MAC layer executes the CG-SDT procedure during this process.

[0252] The UE described in S706 can be executed using the traditional SDT procedure, the specific procedure being the same as... Figure 6 S606 in the illustrated embodiment is similar and can be referenced interchangeably. The difference lies in that, before data transmission, the RRC layer selects a feature or feature combination; the specific process can also be referred to the description of feature selection or feature combination in S6032 or S7032. Optionally, the RRC layer may notify the MAC layer of the selected feature or feature combination, or notify the MAC layer of the corresponding CG-SDT resource for the feature or feature combination; this application does not limit this.

[0253] S707: When the MAC layer determines that the CG-SDT condition is not met, the MAC layer continues to determine whether the RA-SDT condition is met.

[0254] When the MAC layer determines that the RA-SDT condition is met, S708-S713 are executed; when the MAC layer determines that the RA-SDT condition is not met, S714-S715 are executed.

[0255] S708: When the MAC layer determines that the RA-SDT condition is met, the MAC layer sends a third message to the RRC layer, the third message indicating that the condition for initiating SDT is met. Optionally, the third message may also indicate that the RA-SDT condition is met (i.e., the RA-SDT scheme is available).

[0256] S709: After receiving the third message from the MAC layer, (assuming the RRC layer determines that the first SDT condition is met), the RRC layer selects a first feature or feature combination and determines whether the first feature or feature combination satisfies the third SDT condition. The third SDT condition is used to determine whether the selected feature or feature combination can implement SDT.

[0257] In S709, the process of the RRC layer selecting the first feature or a combination of features, and the third SDT condition, can be referenced. Figure 6 The description of S608 in the illustrated embodiment will not be repeated here.

[0258] When the RRC layer determines that the third SDT condition is not met, the UE executes S710-S711; when the RRC layer determines that the third SDT condition is met, the UE executes S712-S713.

[0259] Optionally, the RRC layer may also reselect the second characteristic or characteristic combination when the first characteristic or characteristic combination does not meet the third SDT condition. For details, please refer to the description of the MAC layer reselecting the characteristic or characteristic combination in S608, which will not be repeated here.

[0260] S710: When the RRC layer determines that the third SDT condition is not met, the RRC layer sends a fourth message to the MAC layer, the fourth message being used to indicate the initiation of non-SDT random access. It should be noted that S710 is an optional step; the MAC layer can also determine the initiation of non-SDT random access during the UE implementation process.

[0261] Optionally, the RRC layer can also notify the MAC layer of the currently selected feature or feature combination, or the random access resource corresponding to the currently selected feature or feature combination, so that the MAC layer can initiate random access using the random access resource corresponding to the feature or feature combination selected by the RRC. Optionally, the RRC layer can notify the MAC layer of the currently selected feature or feature combination, or the random access resource corresponding to the currently selected feature or feature combination, through the fourth message.

[0262] S711: The UE performs a normal RRC connection recovery procedure, including S7111 and S7112.

[0263] S7111: Same as S7031 in S703.

[0264] S7112: During the timing of the second timer, the MAC layer performs non-SDT random access. Similar to S7032, the similarities can be referenced. Unlike S7032, the RRC layer does not select a feature or feature combination before executing S7112, because a feature or feature combination has already been selected in S709.

[0265] S712: When the RRC layer determines that the third SDT condition is met, the RRC layer sends a fifth message to the MAC layer. The fifth message is used to indicate random access to initiate SDT. It should be noted that S712 is an optional step; the MAC layer can also determine random access to initiate SDT (i.e., RA-SDT) during the UE implementation process.

[0266] Optionally, the RRC layer can also notify the MAC layer of the currently selected feature or feature combination, or the random access resource corresponding to the currently selected feature or feature combination, so that the MAC layer can initiate random access using the random access resource corresponding to the feature or feature combination selected by the RRC. Optionally, the RRC layer can notify the MAC layer of the currently selected feature or feature combination, or the random access resource corresponding to the currently selected feature or feature combination, through the fifth message.

[0267] S713: After the RRC layer determines that the third SDT condition is met (optionally, after sending the fifth message to the MAC layer), the UE executes the SDT procedure. The UE's SDT procedure in S713 can be referenced from... Figure 6 The description in S612 of the illustrated embodiment, namely S7131-S7132, can be referred to as S6121-S6122, and will not be repeated here.

[0268] S714: When the MAC layer determines that the RA-SDT condition is not met, the MAC layer sends a sixth message to the RRC layer, the sixth message being used to indicate that the condition for initiating SDT is not met.

[0269] S715: Same as S703, that is, S7151 and S7152 can be referred to S7031 and S7032, which will not be repeated here.

[0270] Figure 7 The illustrated embodiment provides a communication method in which, upon receiving an indication from the MAC layer that the conditions for initiating SDT (Software-Defined Timeout) are met, the RRC layer selects a feature or a combination of features, and determines whether a third SDT condition is met based on the selected feature or feature combination. Then, it decides whether to initiate the SDT procedure based on whether the third SDT condition is met. This method avoids the phenomenon where the RRC layer erroneously starts the first timer to initiate the SDT procedure when the MAC layer cannot perform the SDT procedure. This avoids the adverse effects on power consumption and data transmission latency caused by erroneously starting the first timer, or the waste of air interface resources and / or signaling. Therefore, this method can guarantee reduced UE power consumption and data transmission latency, or reduce waste of air interface resources and / or signaling.

[0271] See below. Figure 8 The flowchart shown illustrates a communication method provided in an embodiment of this application. It should be noted that in this embodiment, the MAC layer of the UE performs a step of selecting features or a combination of features.

[0272] S801-S807 and Figure 6 In the illustrated embodiment, S601-S607 are the same, and S814-S815 are the same. Figure 6In the illustrated embodiment, steps S613-S614 are the same, and identical steps can be referred to each other, so they will not be described again here. The difference lies in steps S808-S813 after the MAC layer determines that the RA-SDT condition is met. These steps will be described in detail below.

[0273] S808: When the UE's MAC layer determines that the RA-SDT conditions are met, it sends a third message to the RRC layer. The third message indicates that the conditions for initiating SDT are met. In some embodiments, the third message may also indicate that the RA-SDT conditions are met (i.e., the RA-SDT scheme is available).

[0274] S809: After receiving the third message, the RRC layer (assuming the RRC layer determines that the first SDT condition is met) restores the SDT RB and starts the first timer to initiate the SDT process (i.e., the RRC connection recovery process for SDT).

[0275] The SDT RB is the RB used to perform SDT, such as Figure 3 As shown. Optionally, the SDT RB can be configured for the base station.

[0276] S810: After determining that the RA-SDT condition is met, the MAC layer selects a first characteristic or a combination of characteristics, and determines whether the selected first characteristic or combination of characteristics satisfies the third SDT condition. The third SDT condition is used to determine whether the selected characteristic or combination of characteristics can achieve SDT.

[0277] The process by which the MAC layer selects the first feature or a combination of features, and the third SDT condition, can be referred to... Figure 6 The description of S608 in the illustrated embodiment will not be repeated here.

[0278] When the MAC layer determines that the third SDT condition is not met, the UE executes S811-S812; when the MAC layer determines that the third SDT condition is met, the UE executes S813.

[0279] S811: When the MAC layer determines that the third SDT condition is not met, the MAC layer sends a fourth message to the RRC layer, the fourth message being used to indicate the cancellation of the SDT (RA-SDT) process.

[0280] For example, the fourth message may indicate "SDT not initiated, or the selected feature or combination of features does not include SDT, or cancel the SDT process," etc.

[0281] S812: The RRC layer cancels the SDT (RA-SDT) procedure, and the UE performs a normal RRC connection recovery procedure, including S8121 and S8122.

[0282] S8121: The RRC layer stops the first timer and starts the second timer (T319) to initiate a normal RRC connection recovery process. The second timer is used for timing the normal RRC connection recovery process.

[0283] Optionally, the RRC layer can also pause the SDT RB.

[0284] S8122: During the timing of the second timer, the MAC layer performs non-SDT random access.

[0285] In some embodiments, when the random access resources configured by the base station contain a feature or feature combination corresponding to a random access resource selected by the MAC layer, the MAC layer uses the random access resource to initiate random access; when the random access resources configured by the base station do not contain the feature or feature combination corresponding to a random access resource, the MAC layer can use ordinary random access resources (different from all the features or feature combinations corresponding to random access resources configured by the base station) to initiate random access, or use a second feature or feature combination corresponding to a random access resource to initiate random access.

[0286] S813: When the MAC layer determines that the third SDT condition is met, during the operation of the first timer, the MAC layer executes the RA-SDT process (i.e., performs random access including SDT). Specifically, the MAC layer initiates random access and implements SDT during the random access process. For details, please refer to [reference needed]. Figure 6 The description in S6122 of the illustrated embodiment will not be repeated here.

[0287] Figure 8The illustrated embodiment provides a communication method in which the UE's MAC layer, after determining that a second SDT condition is met, notifies the RRC layer to initiate an SDT procedure. The MAC layer can also select a feature or a combination of features; when it determines that a third SDT condition is not met based on the feature or feature combination, the MAC layer notifies the RRC layer to cancel the SDT procedure. Through this method, after the RRC layer initiates the SDT procedure and starts the first timer, when the MAC layer determines that the SDT procedure cannot be implemented, it can notify the RRC layer to cancel the SDT procedure, thereby stopping the first timer and initiating a normal RRC connection recovery procedure. Since this method can stop the first timer as quickly as possible when it is mistakenly started, it can avoid the adverse effects on power consumption and data transmission latency caused by mistakenly starting the first timer, or the waste of air interface resources and / or signaling. Therefore, this method can guarantee reduced UE power consumption and data transmission latency, or reduce waste of air interface resources and / or signaling.

[0288] It should be noted that the embodiments provided in this application do not limit the order of each step, nor do they restrict each step to be mandatory. Furthermore, the embodiments of this application do not limit the names of the various messages involved; any message can be replaced with instructions, notifications, information, etc.

[0289] based on Figure 6 or Figure 7 As shown in the embodiments, this application also provides a communication method, which can be applied to, for example... Figure 1 The mobile communication system shown below. (The following is in conjunction with...) Figure 9 The methods provided in the embodiments of this application will be described.

[0290] S901: When the UE is in the RRC inactive state, after determining that the conditions for initiating SDT are met, determine the first feature or feature combination.

[0291] Optionally, in this embodiment, the MAC layer of the UE determines whether the SDT initiation condition is met. Optionally, the SDT initiation condition may include the second SDT condition and the RA-SDT condition in the above embodiments. It should be noted that this embodiment assumes that all ad conditions in the first SDT condition are met, that is, the condition ad in the first SDT condition is no longer considered.

[0292] In one implementation, the UE may select the first feature or feature combination from at least one feature or feature combination supported by the UE and the base station. Optionally, the UE may also consider at least one or a combination of the following:

[0293] The selection rules are set, along with the characteristics configured by the base station or the corresponding random access resources, the transmission requirements of the UE, the service currently being performed by the UE, the coverage status of the UE, and the characteristics or combinations of the characteristics preferred by the UE.

[0294] The selection rules can be configured by the base station through system information or other broadcast information, or specified by a protocol; this application does not limit this. For example, the selection rules may include the priority of features or feature combinations. The at least one feature or feature combination supported by the base station may be notified by the base station through system information, or determined by the UE based on the random access resources corresponding to the at least one feature or feature combination configured by the base station; this application does not limit this. The UE's preferred feature or feature combination may be determined by the UE based on the at least one feature or feature combination supported by the base station, or by the random access resources corresponding to the at least one feature or feature combination configured by the base station.

[0295] The specific process by which the UE selects the first feature or a combination of features can be referred to in the above embodiments for the specific description of the MAC layer or RRC layer selecting features or a combination of features, which will not be repeated in detail here.

[0296] S902: When the first feature or feature combination includes the SDT feature, and the random access resources configured by the base station contain the random access resources corresponding to the first feature or feature combination, the UE performs the SDT procedure.

[0297] Optionally, in this embodiment of the application, the UE may perform the SDT procedure through the following steps A1-A2:

[0298] A1: Restore the SDT radio bearer RB and start the first timer; wherein, the first timer is used to detect whether the SDT process is successful, and the SDT RB is the RB used to perform SDT. Optionally, the UE's RRC layer can execute step A1, and the SDT RB can be configured by the base station.

[0299] A2: During the first timer's timing, random access is initiated using the first feature or a feature combined with the corresponding random access resource, and target data is sent during the random access process; wherein, the target data is carried in the SDT RB. Optionally, the UE's MAC layer can execute step A2.

[0300] In a first implementation, after the UE's MAC layer determines that the SDT initiation condition is met, the MAC layer determines the first feature or feature combination. Optionally, the MAC layer may also determine whether the first feature or feature combination satisfies a third SDT condition.

[0301] Optionally, the MAC layer may refer to Figure 6 As described in S608 of the illustrated embodiment, the first feature or feature combination is selected. Optionally, the third SDT condition is used to determine whether the selected feature or feature combination can implement SDT. For a detailed description, please refer to the detailed description of the third SDT condition in S608, which will not be repeated here. When the first feature or feature combination satisfies the third SDT condition, it means that the first feature or feature combination contains the SDT feature, and the random access resources configured by the base station contain random access resources corresponding to the first feature or feature combination.

[0302] Optionally, when the MAC layer determines that the first feature or combination of features satisfies the third SDT condition, the MAC layer may send a first message to the RRC layer of the UE. The first message indicates that the condition for initiating an SDT is met. After receiving the first message, the RRC layer may execute step A1 above.

[0303] In the second implementation, after the UE's MAC layer determines that the conditions for initiating SDT are met, the MAC layer sends a second message to the RRC layer, the second message indicating that the conditions for initiating SDT are met; the RRC layer selects the first feature or feature combination. Optionally, the RRC layer can also determine whether the first feature or feature combination satisfies the third SDT condition. When the first feature or feature combination satisfies the third SDT condition, it means that the first feature or feature combination contains an SDT feature, and the random access resources configured by the base station contain random access resources corresponding to the first feature or feature combination.

[0304] Optionally, the RRC layer can refer to Figure 7 As described in S709 of the illustrated embodiment, a first characteristic or a combination of characteristics is selected.

[0305] Optionally, in this embodiment, when the RRC layer determines that the first feature or feature combination includes the SDT feature, and the random access resources configured by the base station contain random access resources corresponding to the first feature or feature combination, the RRC layer can execute step A1 and can also send a third message to the MAC layer; the MAC layer receives the third message from the RRC layer, and the third message is used to instruct the MAC layer to initiate random access for SDT. Thus, the MAC layer can execute step A2 after receiving the third message. Optionally, the RRC layer can also notify the MAC layer of the selected first feature or feature combination, or notify the MAC layer of the random access resources used by the first feature or feature combination. For example, the third message can also indicate the first feature or feature combination, or indicate the random access resources corresponding to the first feature or feature combination.

[0306] Optionally, when the first feature or combination of features does not include the SDT feature, and / or when the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or combination of features, the RRC connection recovery process is executed. Optionally, after the UE executes the RRC connection recovery process, the UE can enter the connected state.

[0307] In the first embodiment above, when the MAC layer determines that the first feature or feature combination does not include the SDT feature, and / or that the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination, the MAC layer may send a fourth message to the RRC layer. The fourth message is used to indicate that the conditions for initiating SDT are not met. Upon receiving the fourth message, the RRC layer can then perform a normal RRC connection recovery process.

[0308] In the second embodiment above, when the RRC layer determines that the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination, the RRC layer executes the RRC connection recovery process.

[0309] Optionally, the RRC can initiate an RRC connection recovery process by starting a second timer.

[0310] Optionally, when the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the UE may further perform non-SDT random access by: initiating random access using the first random access resource configured by the base station; wherein, when the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the first random access resource is the same as the random access resource corresponding to the second feature or feature combination configured by the base station, or the first random access is a normal random access resource; when the random access resources configured by the base station contain a random access resource corresponding to the first feature or feature combination, the first random access resource is the random access resource corresponding to the first feature or feature combination.

[0311] Wherein, the second feature or feature combination can be the feature or feature combination reselected by the RRC layer when the random access resources corresponding to the first feature or feature combination do not exist in the random access resources configured in the base station.

[0312] Optionally, the second feature or feature combination has a lower priority than the first feature or feature combination. Optionally, when the RRC layer reselects a feature or feature combination, it may not select a feature or feature combination with a lower priority from the previously selected feature or feature combination, but may select a feature or feature combination with a higher priority from the previously selected feature or feature combination. Optionally, the first feature or feature combination includes a feature from the second feature or feature combination. For example, the first feature or feature combination includes: redcap UE feature + SDT feature, and the second feature or feature combination includes redcap UE feature.

[0313] Optionally, the MAC layer of the UE can perform the above-mentioned non-SDT random access.

[0314] Optionally, in embodiments of this application, the first feature or combination of features includes at least one of the following:

[0315] SDT features, network slicing features, low-capability or reduced-capability UE redcap UE features, and coverage enhancement CE UE features.

[0316] This application provides a communication method. In this method, the UE can perform an SDT procedure after meeting the conditions for initiating SDT, when the selected first feature or feature combination includes an SDT feature, and the random access resources configured by the base station contain a corresponding random access resource for the first feature or feature combination. Compared to the traditional approach where the UE initiates the SDT procedure as soon as the conditions for initiating SDT are met, the method provided in this application only initiates the SDT procedure when the selected feature or feature combination can achieve SDT. This avoids the phenomenon of mistakenly starting the first timer to initiate the SDT procedure when it cannot be achieved, thereby avoiding the adverse effects on power consumption and data transmission latency caused by mistakenly starting the first timer, or the problem of wasting air interface resources and / or signaling. Therefore, this method can guarantee a reduction in UE power consumption and data transmission latency, or a reduction in wasted air interface resources and / or signaling.

[0317] based on Figure 8 As shown in the embodiments, this application also provides a communication method, which can be applied to, for example... Figure 1 The mobile communication system shown below. (The following is in conjunction with...) Figure 10 The methods provided in the embodiments of this application will be described.

[0318] S1001: When the UE is in the RRC inactive state, after determining that the conditions for initiating SDT are met, the SDT process is started, and the first feature or feature combination is determined.

[0319] Optionally, in this embodiment, the MAC layer of the UE determines whether the SDT initiation condition is met. Optionally, the SDT initiation condition may include the second SDT condition and the RA-SDT condition in the above embodiments. It should be noted that this embodiment assumes that all ad conditions in the first SDT condition are met, that is, the condition ad in the first SDT condition is no longer considered.

[0320] Optionally, the process by which the UE selects the first feature or a combination of features can be referred to in S901, and will not be repeated here.

[0321] S1002: When the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination, the SDT process is cancelled.

[0322] Optionally, in this embodiment, the MAC layer may send a first message to the RRC layer when it determines that the conditions for initiating SDT are met. The first message is used to indicate that the SDT conditions are met. The RRC layer may initiate the SDT process after receiving the first message.

[0323] Optionally, the RRC layer can initiate the SDT process through the following steps:

[0324] Restore the SDT radio bearer RB and start the first timer; wherein, the first timer is used to detect whether the SDT process is successful; wherein, the SDT RB is the RB used to perform SDT;

[0325] When the MAC layer determines that the SDT initiation condition is met, it can also determine the first characteristic or characteristic combination, and judge whether the first characteristic or characteristic combination satisfies the third SDT condition. Optionally, the MAC layer can refer to Figure 6 As described in S608 of the illustrated embodiment, the first feature or feature combination is selected. Optionally, the third SDT condition is used to determine whether the selected feature or feature combination can implement SDT. For a detailed description, please refer to the detailed description of the third SDT condition in S608, which will not be repeated here. When the first feature or feature combination satisfies the third SDT condition, it means that the first feature or feature combination contains the SDT feature, and the random access resources configured by the base station contain the random access resources corresponding to the first feature or feature combination; when the first feature or feature combination does not satisfy the third SDT condition, it means that the first feature or feature combination does not contain the SDT feature, and / or, the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination.

[0326] In one implementation, when the MAC layer determines that the first feature or feature combination does not include the SDT feature, and / or that the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination, the MAC layer may send a second message to the RRC layer. Upon receiving the second message, the RRC layer cancels the SDT procedure. The second message is used to notify the RRC layer to cancel the SDT procedure. Optionally, the RRC layer can cancel the SDT procedure through the following steps:

[0327] The RRC layer stops the first timer, and / or the RRC layer pauses the SDT RB.

[0328] In this embodiment, when the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination, the method further includes: performing an RRC connection recovery process.

[0329] Optionally, the RRC layer may start a second timer to initiate the RRC connection recovery process.

[0330] Optionally, during the RRC connection recovery process, the MAC layer may perform non-SDT random access through the following steps: initiating random access using the first random access resource configured by the base station; wherein, when the random access resource configured by the base station does not contain the random access resource corresponding to the first feature or feature combination, the first random access resource is the same as the random access resource corresponding to the second feature or feature combination configured by the base station, or the first random access is a normal random access resource; when the random access resource configured by the base station contains the random access resource corresponding to the first feature or feature combination, the first random access resource is the random access resource corresponding to the first feature or feature combination.

[0331] Wherein, the second feature or feature combination can be a feature or feature combination reselected by the MAC layer when the random access resources corresponding to the first feature or feature combination do not exist in the random access resources configured by the base station. Optionally, the second feature or feature combination has a lower priority than the first feature or feature combination. Optionally, when reselecting a feature or feature combination, the MAC layer may not select a feature or feature combination with a lower priority from the previously selected feature or feature combination, but may select a feature or feature combination with a higher priority from the previously selected feature or feature combination. Optionally, the first feature or feature combination includes a feature from the second feature or feature combination, for example, the first feature or feature combination includes: redcap UE feature + SDT feature, and the second feature or feature combination includes redcap UE feature.

[0332] In another implementation, when the first feature or feature combination selected by the MAC layer includes an SDT feature, and the random access resources configured by the base station contain a random access resource corresponding to the first feature or feature combination, during the timing of the first timer, the MAC layer initiates random access using the random access resource corresponding to the first feature or feature combination, and sends target data during the random access process; wherein the target data is carried in the SDT RB. The process of the MAC layer performing random access can be referred to... Figure 4 or Figure 5 This will not be elaborated upon here.

[0333] Optionally, in embodiments of this application, the first feature or combination of features includes at least one of the following:

[0334] SDT features, network slicing features, low-capability or reduced-capability UE redcap UE features, and coverage enhancement CE UE features.

[0335] This application provides a communication method. In this method, a UE can initiate an SDT (Service Deployment Technology) procedure when the conditions for initiating SDT are met; then, when the first feature or feature combination selected by the UE does not include an SDT feature, and / or the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the SDT procedure is cancelled. Since this method can promptly cancel the SDT procedure when the feature or feature combination selected by the UE cannot implement SDT, it can also quickly stop the first timer when it is mistakenly started, avoiding adverse effects on power consumption and data transmission latency caused by mistakenly starting the first timer, or problems such as wasted air interface resources and / or signaling. Therefore, this method can guarantee reduced UE power consumption and data transmission latency, or reduce wasted air interface resources and / or signaling.

[0336] based on Figure 8 and Figure 10 The embodiment shown in this application also provides an embodiment of a communication method. In this embodiment, it is assumed that the selection of a feature or feature combination is performed by the MAC layer. The solution provided in this embodiment can be summarized as follows: when the MAC layer selects a feature or feature combination that does not include SDT, the MAC layer indicates first information to the upper layer (e.g., the RRC layer). The first information indicates "SDT not initiated, or the selected feature or feature combination does not include SDT, or the SDT process is cancelled," etc. The RRC layer suspends SDT RB (optional); the RRC layer stops the first timer and starts a second timer (e.g., T319), which is a timer that needs to be started when the UE initiates a normal RRC connection recovery process (e.g., when sending an RRC Resume Request). It should be noted that this embodiment is based on... Figure 8 or Figure 10 The embodiments shown are specific examples, and therefore, the same or corresponding steps can be referred to each other.

[0337] Based on the above description, a specific data transmission process will now be used as an example. Assume that the current redcap UE has data transmission requirements; for detailed procedures, please refer to [link to relevant documentation]. Figure 11 As shown. There are no restrictions. Figure 11 The order of each step is not fixed, nor is it required that each step be mandatory. Furthermore, the redcap UE feature can be replaced with other features or combinations thereof; this application does not impose any restrictions on this.

[0338] S1101: When uplink data arrives at the UE's SDT RB, the UE's MAC layer determines whether the second SDT condition is met. If yes, then execute S1105; otherwise, execute S1102.

[0339] Optionally, when the UE has uplink data transmission requirements, the UE determines whether the conditions for initiating SDT (e.g., RRC connection recovery procedure for SDT) are met. For example, the UE's RRC layer determines whether the first SDT condition is met, and the UE's MAC layer determines whether the second SDT condition is met. This embodiment of the application illustrates this by taking the satisfaction of both ad in the first SDT condition as an example. When the UE determines whether the second SDT condition is met, if the second SDT condition is not met, S1102 is executed; if the second SDT condition is met, S1105 is executed.

[0340] S1102: When the MAC layer determines that the second SDT condition is not met, it instructs the upper layer (the following description in this application uses the RRC layer as an example) not to meet the condition for initiating an SDT.

[0341] In some embodiments, the UE (e.g., the MAC layer) may continue to select a feature or feature combination after determining that the conditions for initiating an SDT are not met. In this case, in addition to indicating to the upper layer that the conditions for initiating an SDT are not met, it may also indicate the selected feature or feature combination.

[0342] S1103: The RRC layer initiates a normal RRC connection recovery process.

[0343] The normal RRC recovery process here can be understood as entering the RRC connection state and then performing data transmission.

[0344] S1104: The MAC layer performs a non-SDT random access procedure.

[0345] It should be noted that this application does not limit the order of S1103 and S1104.

[0346] S1105: When the MAC layer determines that the second SDT condition is met, it continues to determine whether the CG-SDT condition is met. If it is met, S1106 is executed; otherwise, S1109 is executed.

[0347] S1106: When the MAC layer determines that the CG-SDT conditions are met, it instructs the RRC layer to meet the conditions for initiating SDT.

[0348] S1107: The RRC layer initiates the SDT procedure. Optionally, the RRC layer may restore the SDT RB and start the first timer.

[0349] S1108: The MAC layer performs the CG-SDT process. Optionally, the MAC layer may select a feature or a combination of features before data transmission. Optionally, the feature or combination of features selected by the MAC layer includes the SDT feature.

[0350] Through S1106-S1108, the UE can choose to transmit small packet data via CG-SDT. For example, the UE can transmit small packet data that includes SDT features or a combination of features through CG-SDT resources.

[0351] For example, if the currently arriving data is a high-priority data corresponding to slicing, and the UE determines that the data meets the conditions for small packet data transmission, the UE can transmit the small packet data of the slicing service through CG-SDT resources. The base station can identify that the currently transmitted data is the small packet data of the slicing service through the logical channel identifier carrying the data.

[0352] For example, if the incoming data is from a redcap UE and the redcap UE determines that the data meets the conditions for small packet data transmission, the redcap UE can transmit the small packet data through CG-SDT resources. The base station can identify that the data being transmitted is a small packet data of the redcap UE through the CG-SDT resources (which can be understood as the CG-SDT resources being specifically configured by the base station for the redcap UE) or through the redcap UE's I-RNTI.

[0353] For example, if the incoming data is a high-priority data for a redcap UE, and the redcap UE determines that the data meets the conditions for small packet data transmission, then the redcap UE can transmit the high-priority slice small packet data through CG-SDT resources. The base station can identify that the currently transmitted data is small packet data for the redcap UE's slice service through the CG-SDT resources (this can be understood as the CG-SDT resources being specifically configured by the base station for the redcap UE); or it can identify that the currently transmitted data is small packet data for the redcap UE's slice service through the redcap UE's I-RNTI and the logical channel identifier carrying the data. In this case, the UE's choice to transmit small packet data with a specific feature or combination of features through CG-SDT resources implicitly represents the UE performing the selection of a specific feature or combination of features.

[0354] This embodiment does not limit the order of S1107 and S1108.

[0355] S1109: After the MAC layer determines that the CG-SDT condition is not met, it continues to determine whether the RA-SDT condition is met. If it is met, S1110 is executed; otherwise, S1102 is executed.

[0356] S1110: The MAC layer determines that the RA-SDT conditions are met and instructs the RRC layer to meet the conditions for initiating SDT.

[0357] S1111: The RRC layer initiates the SDT procedure, including: restoring the SDT RB and starting the first timer.

[0358] S1112: Before data transmission, the MAC layer selects a feature or a combination of features (i.e., redcap feature + SDT feature). The MAC layer determines whether there are currently available random access resources with redcap feature + SDT feature (i.e., whether there are random access resources corresponding to redcap feature + SDT feature among the random access resources configured by the base station through system information). If they exist, proceed to S1113; otherwise, proceed to S1114.

[0359] Optionally, the UE may select a feature or a combination of features when selecting random access resources, or the UE may select a feature or a combination of features before selecting random access resources.

[0360] Optionally, the UE's determination of whether there are available random access resources for a certain feature or combination of features (e.g., redcap UE feature + SDT feature) can be equivalent to the UE selecting a feature or combination of features.

[0361] This application does not restrict the order of S1111 and S1112.

[0362] S1113: When the MAC layer determines that there is random access resource corresponding to the redcap + SDT feature, the MAC layer executes the RA-SDT procedure. During this procedure, the MAC layer can use the random access resource with the redcap + SDT feature to initiate random access and transmit small packet data during this random access process.

[0363] S1114: When the MAC layer determines that there is no random access resource corresponding to the redcap feature + SDT feature, the MAC layer indicates the first information to the RRC layer, instructing the RRC layer to cancel the SDT process.

[0364] For example, if the UE selects a feature or feature combination based on the implementation or the set priority rules, but the feature or feature combination does not include SDT, then the first information needs to be sent.

[0365] S1115: RRC layer, cancels the SDT procedure and executes a normal RRC connection recovery procedure (i.e., an RRC connection recovery procedure for non-SDT). In S1115, the RRC layer can stop the first timer and / or pause the SDT RB to cancel the SDT procedure. The RRC layer can start the second timer (T319) to initiate a normal RRC connection recovery procedure.

[0366] It should be noted that suspending SDT RBs can be an optional step, as the UE will resume these RBs after receiving the RRC Resume message and entering the RRC connected state. When SDT RBs are not suspended, the UE can also automatically avoid transmitting SDT RB data in msg3 / msgA.

[0367] S1116: The MAC layer performs a non-SDT random access procedure.

[0368] This application does not specify the order of S1115 and S1116.

[0369] based on Figure 6 and Figure 9 The embodiment shown in this application also provides an embodiment of a communication method. In this embodiment, it is assumed that the selection of a feature or feature combination is performed by the MAC layer. The solution provided in this embodiment can be summarized as follows: before instructing the RRC layer that the conditions for initiating an SDT are met, the MAC layer should select a feature or feature combination and determine whether the feature or feature combination implements an SDT. It should be noted that this embodiment is based on... Figure 6 or Figure 9 The embodiments shown are specific examples, and therefore, the same or corresponding steps can be referred to each other.

[0370] Based on the above description, a specific data transmission process will now be used as an example. Assume that the current redcap UE has data transmission requirements; for detailed procedures, please refer to [link to relevant documentation]. Figure 12 As shown. There are no restrictions. Figure 12 The order of each step is not fixed, nor is it required that each step be mandatory. Furthermore, the redcap UE feature can be replaced with other features or combinations thereof; this application does not impose any restrictions on this.

[0371] S1201-S1209 and Figure 11 S1101-S1109 in the illustrated embodiments are the same and can be referenced interchangeably, and will not be repeated here.

[0372] S1210: When the MAC layer determines that the RA-SDT condition is met, the MAC layer selects the first feature or feature combination. This embodiment assumes that the MAC layer selects a feature or feature combination based on the random access resources corresponding to at least one feature or feature combination configured by the base station. Therefore, the first feature or feature combination has a corresponding random access resource.

[0373] S1211: The MAC layer determines whether the currently selected feature or feature combination includes the SDT feature. If not, it executes S1202 (it should be noted that in this case, since the MAC layer has already selected the feature or feature combination, the MAC layer does not need to execute the feature or feature combination selection step in subsequent steps); if it includes the feature, it executes S1212.

[0374] In the current situation, when the MAC layer executes S1202, it indicates to the upper layer that the conditions for initiating SDT are not met. At this time, the RRC layer can initiate a non-SDT RRC connection recovery procedure, and the MAC layer can execute a random access procedure according to its selected first characteristic or a combination of characteristics.

[0375] S1212: The MAC layer determines that the currently selected feature or feature combination includes the SDT feature and indicates to the RRC layer that the conditions for initiating an SDT are met. For example, when the selected feature or feature combination is the SDT feature + the redcap UE feature, the MAC layer indicates to the RRC layer that the conditions for initiating an SDT are met.

[0376] S1213: The RRC layer initiates the SDT process, including: restoring the SDT RB and starting the first timer.

[0377] S1214: The MAC layer executes the RA-SDT procedure.

[0378] This embodiment does not limit the order of S1213 and S1214.

[0379] based on Figure 7 and Figure 9 As illustrated in the embodiments, this application also provides an embodiment of a communication method. In this embodiment, it is assumed that the selection of a feature or feature combination is performed by the RRC layer. The solution provided in this embodiment can be summarized as follows: after the MAC layer indicates to the RRC layer that the conditions for initiating an SDT are met, the RRC layer first selects a feature or feature combination and then determines whether the feature or feature combination implements an SDT. It should be noted that this embodiment is based on... Figure 7 or Figure 9 The embodiments shown are specific examples, and therefore, the same or corresponding steps can be referred to each other.

[0380] Based on the above description, a specific data transmission process will now be used as an example. Assume that the current redcap UE has data transmission requirements; for detailed procedures, please refer to [link to relevant documentation]. Figure 13 As shown. There are no restrictions. Figure 13 The order of each step is not fixed, nor is it required that each step be mandatory. Furthermore, the redcap UE feature can be replaced with other features or combinations thereof; this application does not impose any restrictions on this.

[0381] S1301-S1310 and Figure 11 S1101-S1110 in the illustrated embodiment are similar, and the similarities can be referred to each other.

[0382] Since this embodiment selects features or combinations of features using the RRC layer, therefore, with Figure 11 The difference between the embodiments shown is:

[0383] In S1302, when the MAC layer determines that the second SDT condition is not met, it indicates to the RRC layer that the condition for initiating SDT is not met. At this time, the MAC layer cannot directly execute non-SDT random access, but needs to wait for the RRC layer to make a further selection of features or feature combinations.

[0384] Similarly, in S1306, the MAC layer determines that the CG-SDT condition is met and indicates to the upper layer that the condition for initiating SDT is met. At this time, after determining that the condition for initiating SDT is met, the MAC layer does not directly initiate the CG-SDT procedure corresponding to SDT, but only indicates to the RRC layer that the SDT condition is met, and waits for the RRC layer to make further selections of features or feature combinations. In some embodiments, the UE indicating to the upper layer that the condition for initiating SDT is met can be the UE indicating to the upper layer that the condition for initiating CG-SDT is met.

[0385] In S1310, the MAC layer determines that the RA-SDT condition is met and indicates to the uplink that the condition for initiating SDT is met. At this time, after determining that the condition for initiating SDT is met, the MAC layer does not directly initiate the RA-SDT procedure corresponding to SDT, but only indicates to the RRC layer that the SDT condition is met, and waits for the RRC layer to make further selections of features or feature combinations. In some embodiments, the UE indicating to the upper layer that the condition for initiating SDT is met can be the UE indicating to the upper layer that the condition for initiating RA-SDT is met.

[0386] Optionally, in some embodiments, prior to S1301, the UE may also determine its preferred feature or feature combination based on the indication in the cell's broadcast information (e.g., system message) regarding "whether the current cell supports a feature or feature combination, or at least one feature or feature combination supported by the current cell" or "the random access resources corresponding to at least one feature or feature combination (available)". In this way, the UE can refer to its preferred feature or feature combination when selecting features in subsequent feature selection processes.

[0387] S1311: After receiving the instruction in S1310, the RRC layer selects a feature or a combination of features. In this embodiment, the feature or combination of features selected by the RRC layer is the redcap UE feature + SDT feature.

[0388] In some embodiments, the feature or feature combination selected by the RRC layer in this step can be implemented by the UE itself or determined by predefined priority rules. For details, please refer to the description of feature selection or feature combination in the above embodiments, which will not be repeated here.

[0389] S1312: The RRC layer determines whether there are currently available random access resources with the redcap UE feature + SDT feature (i.e., whether there are random access resources corresponding to the redcap feature + SDT feature among the random access resources configured by the base station through system information). If not, execute S1303; otherwise, execute S1313.

[0390] For example, after receiving an indication from the MAC indicating that the conditions for initiating SDT are met, the RRC layer selects a feature or feature combination and determines whether the currently selected feature or feature combination includes SDT.

[0391] The UE determining whether a certain feature or combination of features (e.g., redcap UE feature + SDT feature) is available for random access resources can be equivalent to the UE selecting a feature or combination of features. In some embodiments, this step is predicated on the RRC layer receiving an indication from the MAC layer that the RA-SDT condition is met.

[0392] In the current situation, when no random access resource corresponding to the redcap UE feature + SDT feature exists, in S1303, the RRC layer can also select another feature or feature combination (e.g., the redcap UE feature) and indicate the random access resource corresponding to that feature or feature combination to the MAC layer. In this way, the MAC layer can perform non-SDT random access based on the random access resource corresponding to that feature or feature combination.

[0393] S1313: When the RRC layer determines that there is random access resource corresponding to the redcap feature + SDT feature, the RRC layer initiates the SDT process, including: restoring the SDT RB and starting the first timer.

[0394] For example, the SDT process in this step is an RRC connection recovery process that includes SDT features or a combination of features (redcap features + SDT features).

[0395] S1314: The MAC layer performs the RA-SDT procedure. For example, the MAC layer performs a random access procedure that includes an SDT. For example, the MAC layer performing a random access procedure that includes an SDT may include the MAC layer performing random access based on the random access-related parameters selected by the RRC layer.

[0396] Based on the same technical concept, this application also provides a communication device, which is applied to, for example... Figure 1 The UE in the mobile communication system shown. The communication device is used to implement the communication methods provided in the above embodiments and examples. See also Figure 14As shown, the communication device 1400 includes a communication unit 1401 and a processing unit 1402. Optionally, the processing unit 1402 may include, but is not limited to, a MAC layer processing unit and an RRC layer processing unit.

[0397] The communication unit 1401 is used to receive and transmit signals. Optionally, the communication unit 1401 may include a transceiver.

[0398] In one embodiment, the communication device is used to implement Figure 6 , 7 The embodiment shown in any of the figures 9, 12, or 13. The processing unit 1402 is used for:

[0399] When the UE is in the RRC inactive state, after determining that the conditions for initiating SDT are met, the first feature or a combination of features is determined;

[0400] When the first feature or feature combination includes the SDT feature, and the random access resources configured by the base station contain the random access resources corresponding to the first feature or feature combination, the SDT process is executed.

[0401] Optionally, when determining the first characteristic or a combination of characteristics, the processing unit 1402 is specifically used for:

[0402] The first feature or combination of features is selected from at least one feature or feature combination supported by the UE and the base station, based on at least one or a combination of the following:

[0403] The selection rules are set, along with the characteristics configured by the base station or the characteristics combined with the corresponding random access resources, the transmission requirements of the UE, the services of the UE, and the coverage status of the UE.

[0404] Optionally, the processing unit 1402, when executing the SDT process, is specifically used for:

[0405] Restore the SDT radio bearer RB and start the first timer; wherein, the first timer is used to detect whether the SDT process is successful, and the SDT RB is the RB used to perform SDT;

[0406] During the first timer's timing process, random access is initiated using the first feature or the feature combined with the corresponding random access resource, and target data is sent during the random access process; wherein, the target data is carried in the SDTRB.

[0407] Optionally, the RRC layer processing unit is configured to: restore the SDT radio bearer RB and start a first timer; wherein the first timer is configured to detect whether the SDT process is successful, and the SDT RB is an RB used to execute SDT.

[0408] The MAC layer processing unit is configured to: initiate random access using the first feature or the feature combined with the corresponding random access resource during the first timer's timing process, and send target data during the random access process; wherein the target data is carried in the SDT RB.

[0409] Optionally, when the processing unit 1402 determines the first feature or feature combination after determining that the conditions for initiating SDT are met, the MAC layer processing unit is used to determine the first feature or feature combination after determining that the conditions for initiating SDT are met.

[0410] The MAC layer processing unit is further configured to: send a first message to the RRC layer processing unit before executing the SDT process, the first message being used to indicate that the conditions for initiating SDT are met.

[0411] After determining that the conditions for initiating SDT are met, and when determining the first characteristic or a combination of characteristics, the MAC layer processing unit is configured to: after determining that the conditions for initiating SDT are met, send a second message to the RRC layer processing unit, wherein the second message is used to indicate that the conditions for initiating SDT are met;

[0412] The RRC layer processing unit is used to: select the first feature or a combination of features.

[0413] Optionally, the MAC layer processing unit is configured to: receive a third message from the RRC layer processing unit, the third message being used to instruct the MAC layer processing unit to initiate random access for SDT.

[0414] Optionally, the processing unit 1402 is further configured to: execute an RRC connection recovery process to enable the UE to enter a connected state when the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination. Optionally, the RRC layer processing unit executes the RRC connection recovery process.

[0415] Optionally, the processing unit 1402 is further configured to: initiate random access using the first random access resource configured by the base station when the first feature or feature combination does not include the SDT feature, and / or when the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination; wherein, when the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the first random access resource is the same as the random access resource corresponding to the second feature or feature combination configured by the base station; when the random access resources configured by the base station contain a random access resource corresponding to the first feature or feature combination, the first random access resource is the random access resource corresponding to the first feature or feature combination.

[0416] Optionally, the MAC layer processing unit performs the process of initiating random access.

[0417] Optionally, any feature or combination of features may include at least one of the following:

[0418] SDT features, network slicing features, low-capability or reduced-capability UE redcap UE features, and coverage enhancement CE UE features.

[0419] In another embodiment, the communication device is used to implement Figure 8 , Figure 10 or Figure 11 The embodiment shown in any of the accompanying drawings. The processing unit 1402 is used for:

[0420] When the UE is in the RRC inactive state, after determining that the conditions for initiating SDT are met, the SDT process is started, and the first feature or feature combination is determined;

[0421] When the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination, the SDT process is cancelled.

[0422] Optionally, when determining the first characteristic or a combination of characteristics, the processing unit 1402 is specifically used for:

[0423] The first feature or combination of features is selected from at least one feature or feature combination supported by the UE and the base station, based on at least one or a combination of the following:

[0424] The selection rules are set, along with the characteristics configured by the base station or the characteristics combined with the corresponding random access resources, the transmission requirements of the UE, the services of the UE, and the coverage status of the UE.

[0425] Optionally, when the processing unit 1402 cancels the SDT process:

[0426] After receiving a first message from the MAC layer processing unit, the RRC layer processing unit cancels the SDT process; wherein, the first message is used to notify the RRC layer to cancel the SDT process.

[0427] Optionally, when the processing unit 1402 initiates the SDT process:

[0428] The RRC layer processing unit restores the SDT radio bearer RB and starts a first timer; wherein, the first timer is used to detect whether the SDT process is successful; wherein, the SDT RB is the RB used to perform SDT;

[0429] When the first feature or feature combination includes the SDT feature, and the random access resources configured by the base station contain the random access resources corresponding to the first feature or feature combination, during the timing of the first timer, the MAC layer processing unit initiates random access using the random access resources corresponding to the first feature or feature combination, and sends target data during the random access process; wherein, the target data is carried in the SDT RB;

[0430] When the RRC layer processing unit cancels the SDT process, it is specifically used for:

[0431] Stop the first timer, and / or pause the SDT RB.

[0432] Optionally, the processing unit 1402 is further configured to: execute an RRC connection recovery process when the first feature or feature combination does not include the SDT feature, and / or when the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination. Optionally, the RRC layer processing unit executes the RRC connection recovery process.

[0433] Optionally, the processing unit 1402 is further configured to: initiate random access using the first random access resource configured by the base station when the first feature or feature combination does not include the SDT feature, and / or when the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination; wherein, when the random access resources configured by the base station do not contain a random access resource corresponding to the first feature or feature combination, the first random access resource is the same as the random access resource corresponding to the second feature or feature combination configured by the base station; when the random access resources configured by the base station contain a random access resource corresponding to the first feature or feature combination, the first random access resource is the random access resource corresponding to the first feature or feature combination. Optionally, the MAC layer processing unit executes the random access procedure.

[0434] Optionally, any feature or combination of features may include at least one of the following:

[0435] SDT features, network slicing features, low-capability or reduced-capability UE redcap UE features, and coverage enhancement CE UE features.

[0436] Based on the above embodiments, this application also provides a UE, which can be applied to, for example... Figure 1 The mobile communication system shown can implement the methods in the above embodiments and has the functions of the communication device 1400 provided in the above embodiments. (See also...) Figure 15 As shown, the UE 1500 includes a transceiver 1501 and at least one processor 1502. Optionally, the communication device 1500 further includes a memory 1503. The transceiver 1501, the processor 1502, and the memory 1503 are interconnected.

[0437] Optionally, the transceiver 1501, the at least one processor 1502, and the memory 1503 are interconnected via a bus 1504. The bus 1504 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 15 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0438] The transceiver 1501 is used to receive and transmit signals to enable communication with other devices in the mobile communication system. Optionally, the transceiver 1501 can be implemented using a radio frequency device and an antenna.

[0439] The at least one processor 1502 includes an RRC layer processing unit and a MAC layer processing unit. The RRC layer processing unit executes the steps of the RRC layer to implement its functions. The MAC layer processing unit executes the steps of the MAC layer to implement its functions.

[0440] The functions of the processor 1502, as well as the specific functions of the RRC layer processing unit and the MAC layer processing unit, can be referred to the description in the above embodiments, and will not be repeated here.

[0441] The processor 1502 can be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. The processor 1502 may further include hardware chips. These hardware chips can be application-specific integrated circuits (ASICs), programmable logic devices (PLDs), or combinations thereof. The PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. The processor 1502 can implement the above functions through hardware, or by executing corresponding software.

[0442] The memory 1503 is used to store program instructions, etc. Specifically, the program instructions may include program code, which includes computer operation instructions. The memory 1503 may include random access memory (RAM) and may also include non-volatile memory, such as at least one disk storage device. The processor 1502 executes the program instructions stored in the memory 1503 to implement the above functions, thereby implementing the method provided in the above embodiments.

[0443] Based on the above embodiments, this application also provides a computer program that, when run on a computer, causes the computer to execute the methods provided in the above embodiments.

[0444] Based on the above embodiments, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a computer, causes the computer to perform the methods provided in the above embodiments.

[0445] The storage medium can be any available medium that a computer can access. For example, but not limited to, a computer-readable medium can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage media or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0446] Based on the above embodiments, this application also provides a chip for reading a computer program stored in a memory to implement the method provided in the above embodiments.

[0447] Based on the above embodiments, this application provides a chip system including a processor for supporting a computer device in implementing the functions involved in the communication devices described in the above embodiments. In one possible design, the chip system further includes a memory for storing necessary programs and data of the computer device. This chip system may be composed of chips or may include chips and other discrete components.

[0448] In summary, this application provides a communication method and device. In this method, the UE can perform an SDT procedure after meeting the conditions for initiating SDT, specifically when the selected first feature or feature combination includes an SDT feature, and the base station's configured random access resources contain a corresponding random access resource for that first feature or feature combination. Compared to traditional solutions where the UE initiates the SDT procedure immediately upon meeting the conditions, the method provided in this application only initiates the SDT procedure if the selected feature or feature combination can achieve SDT. This avoids the phenomenon of mistakenly starting the first timer to initiate the SDT procedure when it cannot be achieved, thus preventing adverse effects on power consumption and data transmission latency caused by mistakenly starting the first timer, or the waste of air interface resources and / or signaling. Therefore, this method can guarantee reduced UE power consumption and data transmission latency, or reduce waste of air interface resources and / or signaling.

[0449] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0450] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0451] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0452] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0453] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A communication method applied to a user equipment (UE), characterized in that, include: When the UE is in the Radio Resource Control (RRC) inactive state, after determining that the conditions for initiating Small Packet Transmission (SDT) are met, the SDT process is started, and the first characteristic or a combination of characteristics is determined. The SDT process is cancelled when the first feature or feature combination does not include the SDT feature, and / or the random access resources configured by the base station do not contain the random access resources corresponding to the first feature or feature combination.

2. The method as described in claim 1, characterized in that, Determining the first characteristic or combination of characteristics includes: The first feature or combination of features is selected from at least one feature or feature combination supported by the UE and the base station, based on at least one or a combination of the following: The selection rules are set, along with the characteristics configured by the base station or the characteristics combined with the corresponding random access resources, the transmission requirements of the UE, the services of the UE, and the coverage status of the UE.

3. The method as described in claim 1, characterized in that, Cancellation of the SDT process includes: After receiving a first message from the Media Access Control (MAC) layer, the RRC layer of the UE cancels the SDT procedure; wherein, the first message is used to notify the RRC layer to cancel the SDT procedure.

4. The method as described in claim 3, characterized in that, The SDT initiation process includes: The RRC layer restores the SDT radio bearer RB and starts a first timer; wherein, the first timer is used to detect whether the SDT process is successful; wherein, the SDT RB is the RB used to perform SDT; The method further includes: When the first feature or feature combination includes the SDT feature, and the random access resources configured by the base station contain the random access resources corresponding to the first feature or feature combination, during the timing of the first timer, the MAC layer initiates random access using the random access resources corresponding to the first feature or feature combination, and sends target data during the random access process; wherein, the target data is carried in the SDT RB; The RRC layer cancels the SDT process, including: The RRC layer stops the first timer, and / or the RRC layer pauses the SDT RB.

5. The method according to any one of claims 1-4, characterized in that, When the first feature or combination of features does not include SDT features, and / or the random access resources configured by the base station do not contain random access resources corresponding to the first feature or combination of features, the method further includes: Perform the RRC connection recovery process.

6. The method as described in claim 5, characterized in that, When the first feature or combination of features does not include SDT features, and / or the random access resources configured by the base station do not contain random access resources corresponding to the first feature or combination of features, the method further includes: Random access is initiated using the first random access resource configured by the base station; wherein, when the random access resource configured by the base station does not contain the random access resource corresponding to the first characteristic or the combination of characteristics, the first random access resource is the same as the random access resource corresponding to the second characteristic or the combination of characteristics configured by the base station; when the random access resource configured by the base station contains the random access resource corresponding to the first characteristic or the combination of characteristics, the first random access resource is the random access resource corresponding to the first characteristic or the combination of characteristics.

7. The method according to any one of claims 1-4 and 6, characterized in that, The first feature or combination of features includes at least one of the following: SDT features, network slicing features, low-capability or reduced-capability UE redcap UE features, and coverage enhancement CE UE features.

8. A user equipment (UE), characterized in that, include: A transceiver is used to receive and send signals; Memory is used to store program instructions and data; A processor is configured to read program instructions and data from the memory and implement the method described in any one of claims 1-7 via the transceiver.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when run on a computer, causes the computer to perform the method described in any one of claims 1-7.

10. A chip, characterized in that, The chip is coupled to a memory, and the chip reads a computer program stored in the memory to execute the method described in any one of claims 1-7.

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