WO2023116410A1 - Communication method and device - Google Patents

Abstract

Provided in the embodiments of the present application are a communication method and device. In the method, after an SDT initiation condition is met, when a selected first feature or feature combination includes an SDT feature and there is a random access resource corresponding to the first feature or feature combination among random access resources configured by a base station, a UE can execute an SDT process. Compared with traditional solutions in which a UE initiates an SDT process when an SDT initiation condition is met, by means of the method provided in the embodiments of the present application, a UE initiates an SDT process only when a selected feature or feature combination can realize SDT, thereby avoiding the situation where the SDT process is initiated due to a first timer being mistakenly started when the SDT process cannot be realized, and thus avoiding the adverse effects, which are caused by mistakenly starting the first timer, on the power consumption and the data transmission delay. Therefore, the method can ensure that the power consumption and the data transmission delay of a UE are reduced.

Description

A communication method and device

This application claims the priority of the Chinese patent application with the application number 202111587478.5 submitted to the State Intellectual Property Office of China on December 23, 2021, and the priority of the Chinese patent application with the title of the invention "a communication method, UE and network equipment" , claiming the priority of the Chinese patent application with the application number 202210016639.3 submitted to the State Intellectual Property Office of China on January 7, 2022, and the priority of the Chinese patent application with the title of the invention "a communication method and device", claiming the priority in 2022 The priority of the Chinese patent application with the application number 202210095598.1 filed with the State Intellectual Property Office of China on January 26, 2022, and the priority of the Chinese patent application with the title of the invention "a communication method and device", the entire contents of which are incorporated by reference in In this application.

Cross References to Related Applications

This application is required to be submitted to the China Patent Office on December 23, 2021, the application number is 202111587478.5, the application name is "a communication method, UE and network equipment" and submitted to the China Patent Office on January 7, 2022, and the application number is 202210016639.3, the priority of a Chinese patent application titled "A Communication Method and Device", the entire contents of which are incorporated in this application by reference.

technical field

The present application relates to the technical field of communication, and in particular to a communication method and device.

Background technique

In the research of the 3rd Generation Partnership Project (3GPP) Release 17 (Release 17, referred to as R17), the mobile communication system can support a variety of features (features), such as small packet transmission (small data transmission, SDT) , network slicing, low-capability user equipment (user equipment, UE) or reduced capability UE (redcap UE), and coverage enhancement (coverage enhancement, CE) UE.

It should be noted that the above features can be combined with each other, 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 sclcing as small packet data (small data). The high-priority service data and the like are transmitted through the SDT.

For different features or feature combinations (feature/feature combination), the base station will schedule corresponding transmission resources to meet the transmission requirements or transmission characteristics of different features or feature combinations. The specific process is as follows:

UE in radio resource control (radio resource control, RRC) non-connected state (such as RRC idle state or RRC inactive state) can select features or feature combinations after uplink data arrives and before data transmission; when performing random access procedures In this method, the UE may send signaling or data to the base station through the characteristic or the combination of characteristics corresponding to the random access resource, so as to indicate to the base station the characteristic or combination of characteristics currently selected by the UE, so that the base station may use the characteristic or combination of characteristics as the described The UE schedules transmission resources for this data transmission.

Wherein, the random access resources corresponding to each characteristic or combination of characteristics may be specific to the characteristic or combination of characteristics, and may be different from common random access resources. For example, the mobile communication system may define certain characteristics or characteristics combined with corresponding random access resources as time resources and/or frequency resources that are separate from common random access resources. It should be noted that although the current communication technology supports multiple characteristics or combination of characteristics, it is not limited that each base station must provide random access resources corresponding to all kinds of characteristics or combination of characteristics in each cell.

Currently, UEs that support SDT can implement the RA-based SDT (RA-SDT) process through the following steps:

When the UE has uplink data to be sent and meets the RA-SDT conditions, the UE will initiate the SDT process, including: recovering the SDT radio bearer (radio bearer, RB), starting the timer for SDT (such as the SDT failure detection timer ); and initiate random access to implement SDT during random access.

However, due to various factors, the characteristic or characteristic combination selected by the UE may not contain SDT, or although the characteristic or characteristic combination contains SDT, the base station has not configured the random access resource of the characteristic or characteristic combination, which makes the UE unable to use The random access resource corresponding to the SDT makes the UE unable to implement the SDT process. However, the UE has started a timer for SDT. During the timing of the timer, the UE will detect the signaling or data of the base station, and try the next RRC connection recovery process after timeout. This will not only increase the power consumption of the UE, but also adversely affect the data transmission delay.

Contents of the invention

The present application provides a communication method and device, which are used to reduce the waste of power consumption of the UE and reduce the data transmission delay when the UE does not implement the SDT process.

In the first aspect, the embodiment of the present application provides a communication method, which can be applied to a UE, and specifically includes the following steps:

When the UE is in the RRC inactive state, after determining that the condition for initiating small packet transmission SDT is satisfied, determine the first characteristic or combination of characteristics; when the first characteristic or combination of characteristics includes SDT characteristics, and the random access resources configured by the base station When there is the first characteristic or a corresponding random access resource in combination with the characteristic, perform an SDT process.

In this method, after the UE meets the conditions for initiating SDT, when the selected first feature or feature combination includes the SDT feature, and the random access resource corresponding to the first feature or feature combination exists in the random access resource configured by the base station Execute the SDT process when resources are available. Compared with the traditional solution, the UE initiates the SDT process when it meets the conditions for initiating SDT. In the method provided by the embodiment of this application, the UE initiates the SDT process only when the selected feature or the combination of features can realize the SDT, so as to avoid the situation that the SDT process cannot be realized. In the case of wrongly starting the first timer to initiate the phenomenon of the SDT process, thereby avoiding the adverse impact on power consumption and data transmission delay caused by wrongly starting the first timer or causing waste of air interface resources and/or signaling question. Therefore, the method can ensure reduction of UE power consumption and data transmission delay, or reduce waste of air interface resources and/or signaling.

In a 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 supported by the base station according to at least one or a combination of the following:

Set selection rules, characteristics configured by the base station or characteristics combined with corresponding random access resources, transmission requirements of the UE (such as the characteristics or transmission delay of the currently arriving uplink data), and services performed by the UE , and the coverage state of the UE.

Wherein, the setting selection rule may be configured by the base station through system information or other broadcast information, or stipulated by a protocol, which is not limited in this application. For example, the set selection rule includes the priority of characteristics or combination of characteristics. The at least one characteristic or combination of characteristics supported by the base station may be notified by the base station through system information, or determined by the UE according to at least one characteristic or combination of characteristics configured by the base station and corresponding random access resources, This application is not limited to this.

Optionally, the UE may also select the feature or feature combination with reference to the UE's preferred feature or feature combination. Exemplarily, the UE (such as the MAC layer or the RRC layer, which may also be other protocol layers) may be based on at least one feature or feature combination supported by the base station, or at least one feature or feature combination configured by the base station corresponding to The preferred characteristic or combination of characteristics is determined by randomly accessing resources, and the preferred characteristic or combination of characteristics may also be determined according to at least one characteristic or combination of characteristics supported by the UE.

In a possible design, the UE may perform the SDT process through the following steps:

Resume the SDT radio bearer RB and start a first timer; 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 counting on the first timer During the process, random access is initiated by using the first feature or the feature in combination 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 SDT RB may be configured by the base station. Optionally, the RRC layer of the UE may perform the steps of recovering the SDT RB and starting the first timer, and the MAC layer of the UE may perform the process of initiating random access.

In a possible design, the UE may determine the first characteristic or combination of characteristics after determining that the condition for initiating SDT is met through the following steps: After the MAC layer of the UE determines that the condition for initiating SDT is met, the MAC layer determines The first property or combination of properties. In this case, before the UE executes the SDT process, the MAC layer may also send a first message to the RRC layer of the UE, where the first message is used to indicate that a condition for initiating the SDT is met. Through this method, the MAC layer can notify the RRC layer that the condition for initiating the SDT is met, and the RRC layer can execute the SDT process.

In a possible design, the UE may determine the first characteristic or combination of characteristics after determining that the condition for initiating SDT is met through the following steps, including: after the MAC layer of the UE determines that the condition for initiating SDT is met, the MAC The layer sends a second message to the RRC layer, where the second message is used to indicate that a condition for initiating an SDT is met; the RRC layer selects the first feature or feature combination.

Through this method, the MAC layer can notify the RRC layer after the condition for initiating the SDT is satisfied, so that the RRC layer selects the first characteristic or characteristic combination, and judges whether to execute the SDT process based on the selected characteristic or characteristic combination.

In a possible design, the RRC layer determines that when the first characteristic or characteristic combination includes the SDT characteristic, and the random access resources corresponding to the first characteristic or characteristic combination exist in the random access resources configured by the base station , the RRC layer may also send a third indication to the MAC layer; after the MAC layer receives the third message from the RRC layer, it may initiate random access of SDT, and the third message is used to instruct the MAC layer to initiate Random access of SDT.

Optionally, the RRC layer may also notify the MAC layer of the first characteristic or characteristic combination selected, or the random access resource corresponding to the first characteristic or characteristic combination, so that the MAC layer can use the first The characteristic or the characteristic combines with the corresponding random access resource to initiate random access of the SDT. Exemplarily, the RRC layer may notify the first characteristic or characteristic combination, or the random access resource corresponding to the first characteristic or characteristic combination through the third message.

In a possible design, when the first feature or feature combination does not include the SDT feature, and/or, there is no random access resource corresponding to the first feature or feature combination in the random access resources configured by the base station. When accessing resources, the UE executes an RRC connection recovery process. Optionally, the UE may enter the connected state by performing an RRC connection recovery process.

Optionally, the RRC layer of the UE may execute the RRC connection recovery process, including: the RRC layer starts a second timer for detecting whether the RRC connection recovery process is successful.

In a possible design, when the first feature or feature combination does not include the SDT feature, and/or, there is no random access resource corresponding to the first feature or feature combination in the random access resources configured by the base station. When accessing resources, the UE may also perform the following steps: use the first random access resource configured by the base station to initiate random access; wherein, when the random access resource configured by the base station does not have the first characteristic or a random access resource corresponding to a characteristic combination, the first random access resource is the same as the second characteristic configured by the base station or a random access resource corresponding to a characteristic combination, or is a common random access resource (same as the base station All the configured features or the corresponding random access resources are different); when the first feature or the corresponding random access resources exist in the random access resources configured by the base station, the first random The access resource is a random access resource corresponding to the first characteristic or a characteristic combination.

Wherein, the second characteristic or combination of characteristics may be reselected by the UE when it is determined that there is no random access resource corresponding to the first characteristic or combination of characteristics. Optionally, the priority of the second characteristic or combination of characteristics reselected by the UE is lower than that of the first characteristic or combination of characteristics selected last time. Optionally, when the UE selects the second feature or feature combination, it may not select the feature or feature combination that includes the first feature or feature combination with a lower priority, and may select the first feature or feature combination that has a higher priority A characteristic or a combination of characteristics. Optionally, the first characteristic or combination of characteristics includes the characteristics in the second characteristic or combination of characteristics. Exemplarily, assuming that the priority of the slicing feature is lower than that of the redcap feature, the UE selects the first feature or a combination of features: the 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 a second feature or feature combination: redcap feature, and use the second feature or feature combination to correspond to random access resources The resource initiates random access.

In one possible design, any feature or combination of features includes at least one of the following:

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

In the second aspect, the embodiment of the present application provides a communication method, which can be applied to UE, and the method specifically includes the following steps:

When the UE is in the RRC inactive state, after determining that the conditions for initiating SDT are satisfied, start the SDT process, and determine the first characteristic or combination of characteristics; when the first characteristic or combination of characteristics does not include SDT characteristics, and/or, the When the random access resource configured by the base station does not contain the first characteristic or the random access resource corresponding to the characteristic combination, cancel the SDT process.

In this method, the UE may initiate the SDT process when the condition for initiating SDT is met; then when the first feature or feature combination selected by the UE does not include the SDT feature, and/or, the random access resources configured by the base station When there is no random access resource corresponding to the first characteristic or characteristic combination, cancel the SDT process. Because this method can cancel the SDT process in time when the characteristics or combination of characteristics selected by the UE cannot realize SDT, and furthermore, this method can stop the first timer as soon as possible when the first timer is started by mistake, so as to avoid Enabling the first timer has adverse effects on power consumption and data transmission delay, or causes waste of air interface resources and/or signaling. Therefore, the method can ensure reduction of UE power consumption and data transmission delay, or reduce waste of air interface resources and/or signaling.

In a 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 supported by the base station according to at least one or a combination of the following:

Setting selection rules, characteristics configured by the base station or characteristics combined with corresponding random access resources, transmission requirements of the UE (such as characteristics or transmission delays of the currently arriving uplink data), services of the UE, and the coverage state of the UE.

Wherein, the setting selection rule may be configured by the base station through system information or other broadcast information, or stipulated by a protocol, which is not limited in this application. For example, the set selection rule includes the priority of characteristics or combination of characteristics. The at least one characteristic or combination of characteristics supported by the base station may be notified by the base station through system information, or determined by the UE according to at least one characteristic or combination of characteristics configured by the base station and corresponding random access resources, This application is not limited to this.

Optionally, the UE may also select the feature or feature combination with reference to the UE's preferred feature or feature combination. Exemplarily, the UE (such as the MAC layer or the RRC layer, which may also be other protocol layers) may be based on at least one feature or feature combination supported by the base station, or at least one feature or feature combination configured by the base station corresponding to The preferred characteristic or combination of characteristics is determined by randomly accessing resources, and the preferred characteristic or combination of characteristics may also be determined according to at least one characteristic or combination of characteristics supported by the UE.

In a possible design, the UE may cancel the SDT process through the following steps:

The RRC layer of the UE cancels the SDT process after receiving the first message sent from the MAC layer; wherein, the first message is used to notify the RRC layer to cancel the SDT process.

Optionally, the MAC layer may select a first characteristic or a combination of characteristics, when the first characteristic or combination of characteristics does not include the SDT characteristic, and/or, the random access resource configured by the base station does not include the first Sending a first message to the RRC layer when a characteristic or a characteristic is combined with a corresponding random access resource.

In a possible design, the UE may start 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 the SDT process Whether it is successful; Wherein, the SDT RB is the RB used to execute the SDT. In this case, when the first characteristic or combination of characteristics includes an SDT characteristic, and random access resources corresponding to the first characteristic or combination of characteristics exist in random access resources configured by the base station, in the second During the timing of a timer, the MAC layer may use the first feature or feature in combination with the corresponding random access resource to initiate random access, and send target data during the random access process; wherein, the target data carried in the SDT RB. Optionally, in this case, the RRC layer may cancel the SDT process through the following steps, including: the RRC layer stops the first timer, and/or the RRC layer suspends the SDT RB . Optionally, the SDT RB may be configured by the base station.

In a possible design, when the first feature or feature combination does not include the SDT feature, and/or, there is no random access resource corresponding to the first feature or feature combination in the random access resources configured by the base station. When accessing resources, the method further includes: the UE performs an RRC connection recovery procedure. Optionally, the RRC layer of the UE may perform an RRC connection recovery procedure. Exemplarily, the RRC layer may start a second timer for detecting whether the RRC connection recovery process is successful.

In a possible design, when the first feature or feature combination does not include the SDT feature, and/or, there is no random access resource corresponding to the first feature or feature combination in the random access resources configured by the base station. When accessing resources, the UE may also perform the following steps: use the first random access resource configured by the base station to initiate random access; wherein, when the random access resource configured by the base station does not have the first characteristic or a random access resource corresponding to a characteristic combination, the first random access resource is the same as the second characteristic configured by the base station or a random access resource corresponding to a characteristic combination, or is a common random access resource (same as the base station All the configured features or the corresponding random access resources are different); when the first feature or the corresponding random access resources exist in the random access resources configured by the base station, the first random The access resource is a random access resource corresponding to the first characteristic or a characteristic combination.

Wherein, the second characteristic or combination of characteristics may be reselected by the UE when it is determined that there is no random access resource corresponding to the first characteristic or combination of characteristics. Optionally, the priority of the second characteristic or combination of characteristics reselected by the UE is lower than that of the first characteristic or combination of characteristics selected last time. Optionally, when the UE selects the second feature or feature combination, it may not select the feature or feature combination that includes the first feature or feature combination with a lower priority, and may select the first feature or feature combination that has a higher priority A characteristic or a combination of characteristics. Optionally, the first characteristic or combination of characteristics includes the characteristics in the second characteristic or combination of characteristics. Exemplarily, assuming that the priority of the slicing feature is lower than that of the redcap feature, the UE selects the first feature or a combination of features: the 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 a second feature or feature combination: redcap feature, and use the second feature or feature combination to correspond to random access resources The resource initiates random access.

In one possible design, any feature or combination of features includes at least one of the following:

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

In a third aspect, the embodiment of the present application provides a communication device, including a unit configured to perform each step in any one of the above aspects.

In a fourth aspect, the embodiment of the present application provides a UE, including at least one processing element and at least one storage element, where the at least one storage element is used to store programs and data, and the at least one processing element is used to execute any method provided.

In a fifth aspect, an embodiment of the present application provides a communication system, where the communication system includes a UE and a base station, where the UE can implement the method provided in any of the above aspects.

In a sixth aspect, the embodiment of the present application further provides a computer program, which, when the computer program is run on a computer, causes the computer to execute the method provided in any one of the above aspects.

In the seventh aspect, the embodiment of the present application also provides a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a computer, the computer executes any one of the above-mentioned method provided.

In an eighth aspect, the embodiment of the present application further provides a chip, the chip is used to read a computer program stored in a memory, and execute the method provided in any one of the above aspects.

In a ninth aspect, the embodiment of the present application further provides a chip system, where the chip system includes a processor, configured to support a computer device to implement the method provided in any one of the above aspects. In a possible design, the chip system further includes a memory, and the memory is used to store necessary programs and data of the computer device. The system-on-a-chip may consist of chips, or may include chips and other discrete devices.

Description of drawings

FIG. 1 is a schematic structural diagram of a mobile communication system provided by an embodiment of the present application;

FIG. 2 is a schematic diagram of an RRC connection state transition provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of RBs configured by a base station provided in an embodiment of the present application;

FIG. 4 is a schematic diagram of a four-step random access RA-SDT process flow provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of a two-step random access RA-SDT process provided by an embodiment of the present application;

FIG. 6 is a flowchart of a communication method provided by an embodiment of the present application;

FIG. 7 is a flow chart of another communication method provided by the embodiment of the present application;

FIG. 8 is a flowchart of another communication method provided by the embodiment of the present application;

FIG. 9 is a flowchart of a communication method provided by an embodiment of the present application;

FIG. 10 is a flowchart of another communication method provided by the embodiment of the present application;

FIG. 11 is a flow chart of an example of a communication method provided by an embodiment of the present application;

FIG. 12 is a flow chart of another communication method example provided by the embodiment of the present application;

FIG. 13 is a flow chart of another communication method example provided by the embodiment of the present application;

FIG. 14 is a structural diagram of a communication device provided by an embodiment of the present application;

FIG. 15 is a structural diagram of a UE provided in an embodiment of the present application.

Detailed ways

The present application provides a communication method and device, which are used to reduce the waste of power consumption of the UE and reduce the data transmission delay when the UE does not implement the SDT process. Among them, the method and the device are conceived based on the same technology. Since the principle of solving the problem of the method and the device is similar, the implementation of the device and the method can be referred to each other, and the repetition will not be repeated.

Some terms used in this application are explained below to facilitate the understanding of those skilled in the art.

1) UE is a device that provides voice and/or data connectivity to users. The UE may also be called a terminal device, a mobile station (mobile station, MS), a mobile terminal (mobile terminal, MT) and so on.

For example, the UE may be a handheld device with a wireless connection function, various vehicle-mounted devices, a roadside unit, and the like. At present, some examples of UE are: mobile phone, tablet computer, notebook computer, palmtop computer, mobile internet device (mobile internet device, MID), intelligent sales terminal (point of sale, POS), wearable device, virtual Reality (virtual reality, VR) equipment, augmented reality (augmented reality, AR) equipment, wireless terminals in industrial control (industrial control), wireless terminals in self driving (self driving), remote surgery (remote medical surgery) Wireless terminals in smart grid, wireless terminals in transportation safety, wireless terminals in smart city, wireless terminals in smart home, various Smart meters (smart water meters, smart electricity meters, smart gas meters), eLTE-DSA UEs, devices with integrated access and backhaul (IAB) capabilities, on-board electronic control units (ECUs), etc. , on-board computer, on-board cruise system, telematics box (T-BOX), etc.

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

Currently, examples of some base stations are: new generation Node B (generation Node B, gNB), transmission reception point (transmission reception point, TRP), evolved Node B (evolved Node B, eNB), Node B (Node B, NB ), access point (access point, AP) home base station (for example, home evolved NodeB, or home Node B, HNB), or base band unit (base band unit, BBU), Enterprise LTE Discrete Spectrum Aggregation (Enterprise LTE Discrete Spectrum Aggregation , eLTE-DSA) base station, etc.

In addition, in a network structure, the base station may include a centralized unit (centralized unit, CU) node and a distributed unit (distributed unit, DU) node. This structure separates the protocol layers of the eNB in the long term evolution (LTE) system, the functions of some protocol layers are placed in the CU for centralized control, and the remaining part or all of the functions of the protocol layers are distributed in the DU. Centralized control of DUs.

3), RRC connection status. In the mobile communication system, the RRC connection state of the UE includes three types: RRC connected state (RRC_connected, referred to as connected state), RRC idle state (RRC_idle, referred to as idle state), and RRC inactive state (RRC_inactive, referred to as inactive state).

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

When the UE is in the inactive state, the RRC connection between the UE and the base station is disconnected, but the base station and the UE will continue to save the context information of the UE. 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 context information of the UE, so that the UE can quickly restore to the connected state.

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

4), small data (small data), data packets whose amount of data is less than the set threshold of small data. Exemplarily, small packet data may include, but is not limited to, the following types of data: instant messages of various communication applications (applications, APPs), heartbeat packets or push messages of APPs, and wearable devices, industrial wireless communication devices, or various smart devices. Various periodic data sent by the meter (including: heartbeat packets, monitoring data, meter readings, etc.).

5) A feature or a combination of features is a concept derived for UE data transmission. Exemplarily, current examples of characteristics include: SDT characteristics, slicing characteristics, redcap UE characteristics, CE UE characteristics, etc. It should be noted that the above four characteristics do not limit the characteristics, and the solutions provided in this application may also be applicable to other characteristics proposed in the future.

Exemplarily, the UE with CE UE characteristics may be a UE in weak coverage, for example, at the edge of a cell, or the signal quality of the UE is poor. At this time, the UE may indicate to the base station that the coverage of the current UE is poor through random access resources. , so that the base station schedules multiple repeated transmission resources for the UE.

The SDT feature is: the data currently arriving by the UE in the inactive state satisfies the SDT condition, and the UE can transmit small packets of data in the inactive state without entering the RRC connection state. The resources used by the UE are resources for transmitting small packet data, for example, the UE transmits small packet data through RA-SDT or CG-SDT process.

The Slicing feature is that when the UE has data for a certain Slicing service, the UE can indicate to the base station that the data related to the Slicing service has arrived through random access resources. For example, the data of this service has a higher priority, and the base station can give priority to The data of the service is processed, or the base station may schedule service-specific transmission resources for the data of the service. The Slicing feature may include a Slicing service, for example, the Slicing feature may include a Slicing group (group), where the Slicing group may include at least one Slicing service.

The characteristics of Redcap UE are: the bandwidth capability of redcap UE is low. When redcap UE has a data transmission requirement, redcap UE can indicate to the base station that the current UE is a redcap UE through random access resources, so that the base station can schedule its available transmission for redcap UE Resource, for example, the transmission resource is a transmission resource within the bandwidth available to the redcap UE.

Any two or more features can be combined, which is called feature combination. For example, a redcap UE can perform SDT, that is, the UE supports redcap UE features + SDT features. For another example, the base station may support the SDT feature, the slicing feature, or feature combination (SDT feature+slicing feature). For another example, the slicing feature may include services of the first slicing group and services of the second slicing group, that is, a UE may perform services of the first slicing group and services of the second slicing group.

It should be noted that different UEs may support different characteristics or combination of characteristics according to their own capabilities. In addition, in an actual application scenario, when there is uplink data to be sent, each UE can select a feature or a combination of features according to the actual situation, service requirements, selection rules set by the base station or the user, and other information. Similarly, the characteristics or combinations of characteristics supported by different base stations are also different. In addition, the base station can set the characteristics or combinations of characteristics supported by the managed cells.

In a mobile communication system, after a UE selects a characteristic or a combination of characteristics, it can indicate the characteristic or combination of characteristics currently selected by the UE to the base station by transmitting resources or other information, so that the base station can serve the UE according to the characteristic or combination of characteristics. Allocate corresponding transmission resources for this data transmission.

For example, during the RRC connection resume (RRC connection resume) process, the UE may use the characteristics or combination of characteristics configured by the base station to correspond to random access resources to notify the base station of the characteristic or combination of characteristics selected by the UE. Exemplarily, in the RA-SDT process, when the UE uses the random access resources corresponding to the SDT characteristics to initiate random access, the base station can know that the current UE needs to transmit uplink packet data, so that the UE can complete SDT in the inactive state and save power consumption . For slicing, when the UE performs high-priority services 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 performing high-priority services, so as to allocate corresponding transmission resources for the UE to ensure the The transport characteristics of the business. The redcap UE can use the random access resources corresponding to the characteristics of the redcap UE to indicate to the base station that the UE is a redcap UE, so that the base station can schedule transmission resources on a frequency band suitable for transmission for the redcap UE. The CE UE can use the random access resources corresponding to the CE UE characteristics to indicate to the base station that the UE is a CE UE, so that the base station can schedule transmission resources with multiple repetition times for the CE UE.

For another example, in the process of SDT based on pre-configured (configured grant, CG) resources (referred to as CG-SDT for short), the UE can use selected features or characteristics in combination with corresponding CG resources to transmit small packet data, so that the base station can transmit the packet data according to the UE The CG resource used to transmit the 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 together with the small packet data At least one or a combination of the above to determine the characteristic or combination of characteristics selected by the UE.

6) The RRC connection recovery process can be divided into: the RRC connection recovery process for SDT and the RRC connection recovery process for non-SDT according to whether SDT can be realized.

The RRC connection recovery process used for SDT is also called the SDT process. In this process, the UE can implement SDT in the random access process (that is, perform random access including SDT), that is, perform the RA-SDT process; the UE can also implement the SDT process through the CG-SDT resource, that is, perform CG-SDT process.

The non-SDT RRC connection recovery process is also called a normal (normal) RRC connection recovery process. During this process, the UE may perform non-SDT random access.

It should be noted that the RRC connection recovery process is a process of the RRC layer; while CG-SDT, RA-SDT, and non-SDT random access processes (including ordinary random access processes) are all processes of the MAC layer.

In this embodiment of the application, unless otherwise specified, the involved RRC connection recovery process is a common RRC connection recovery process.

7), "and/or", describes the association relationship of associated objects, indicating that there can be three types of relationships, for example, A and/or B, which can mean: A exists alone, A and B exist simultaneously, and B exists independently Condition. The character "/" generally indicates that the contextual objects are an "or" relationship.

It should be noted that a plurality referred to in this application refers to two or more than two. At least one means one or more.

In addition, it should be understood that in the description of this application, words such as "first" and "second" are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or imply order.

Embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

Fig. 1 shows the structure of a mobile communication system to which the method provided by the embodiment of the present application is applicable. Referring to Fig. 1, the mobile communication system includes: a base station and a UE.

A base station is an entity capable of receiving and transmitting wireless signals on the network side. It is responsible for providing wireless access-related services for UEs within its coverage area, realizing physical layer functions, resource scheduling and wireless resource management, and Quality of Service (QoS, QoS) management, radio access control, and mobility management functions. Through the base station, the UE can access the core network and finally connect to the data network to realize the services of the UE.

Wherein, each base station is responsible for managing at least one cell. Each cell uses corresponding spectrum resources to provide access services for UEs.

UE is an entity capable of receiving and transmitting wireless signals on the user side, and can access the network through a cell managed by a base station. The UE may be various devices that provide voice and/or data connectivity for users, such as vehicle-mounted devices, smart phones, and the like. The UE and the base station can be connected through a Uu interface to realize communication between the two.

In a mobile communication system, according to whether signaling and procedures are related to access, the Uu interface protocol stack can be divided into a non-access stratum (NAS) and an access stratum (AS).

Among them, the NAS is used to process signaling or data transmission between the UE and the core network, and the transmission content may include user information or control information, such as related signaling for service establishment or release, or mobility management information. The structure of the NAS message has nothing to do with the AS, but it needs to be transmitted based on the AS protocol stack.

AS is a protocol adopted by the radio access network, that is, a radio interface protocol, including a control plane protocol stack and a user plane protocol stack. Among them, the user plane protocol stack includes at least the following protocol layers: physical (physical, PHY) layer, (medium access control, MAC) layer, radio link control (radio link control, RLC) layer and packet data convergence protocol (packet Data convergence protocol (PDCP) layer, service data adaptation protocol (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, RRC layer.

It should also be pointed out that the mobile communication system shown in FIG. 1 is used as an example, and does not limit the mobile communication system to which the method provided in the embodiment of the present application is applicable. In short, the embodiments of the present application can also be applied to communication systems of various types and standards, such as: the fifth generation (The 5th Generation, 5G) communication system, the sixth generation (The 6th Generation, 6G) communication system, and future evolution Other standard communication systems, Long Term Evolution (Long Term Evolution, LTE) communication systems, Long Term Evolution-Vehicle Networking (LTE-vehicle, LTE-V) systems and other mobile communication systems.

In the mobile communication system shown in FIG. 1 , the RRC connection state of the UE includes: connected state, idle state, and inactive state. When the UE is in different RRC connection states, it will perform different operations, and different RRC connection states can be switched, as shown in Figure 2:

1. When the UE in the idle state needs to perform data transmission, the UE initiates the RRC connection establishment (RRC connection establishment) process. During the RRC connection establishment process, the UE establishes an RRC connection with the base station by performing a random access process, and enters the connection Then start data transmission with the base station. Wherein, during the random access process, the UE may send an RRC connection request message, such as RRCSetupRequest message, to the base station, and receive an RRC connection establishment message, such as RRCSetup message, from the base station, so as to establish an RRC connection.

2. When the UE does not need to perform data transmission in the future, the base station can release the UE through the RRC connection release (RRC connection release) process, so that the UE enters an idle state or an inactive state.

For example, the base station sends an RRC connection release message with a suspend indication (suspend indication), such as a RRCRelease with suspend indication message, so that the UE enters an inactive state.

For another example, the base station sends an RRC connection release message, such as an RRCRelease message, to make the UE enter an idle state.

3. The UE in the inactive state can also return to the connected state through the RRC connection resume (RRC connection resume) process. During the RRC connection recovery process, the UE can restore the RRC connection with the base station by performing a random access process, and can start data transmission with the base station after entering the connected state. Wherein, during the random access process, the UE can send an RRC connection recovery request message, such as RRCResumeRequest message, to the base station, and receive an RRC connection recovery message, such as RRCResume message, from the base station, so as to recover the RRC connection. In addition, the base station can also release the UE through the RRC connection release process, so that it turns into an idle state.

The UE in the inactive state generally does not support data transmission, that is, the UE needs to restore the RRC connection again, and can only perform data transmission after entering the connected state. However, in some scenarios, the amount of data packets that need to be transmitted by the UE in the inactive state may be very small (that is, small data packets), and may even be smaller than the signaling required for the UE to return to the connected state. amount of data. In order to avoid unnecessary signaling overhead and power consumption, people in the field have studied the small data transmission (SDT) mechanism, for example, in the 3rd Generation Partnership Project (3rd Generation Partnership Project, 3GPP) version 17 (Release 17, referred to as In the research of R17), the non-active SDT scheme is in the process of standardization.

The SDT mechanism mainly includes an SDT scheme based on random access (RA) (abbreviated as RA-SDT) and an SDT scheme based on pre-configured (configured grant, CG) resources (abbreviated as CG-SDT).

In the RA-SDT scheme, the random access configuration including the RA-SDT configuration is provided by the common control signaling (such as system information) sent by the base station, and the UE needs to read this information every time it selects a new cell. Common control signaling of the cell.

In the CG-SDT solution, the CG-SDT resources are issued by the base station to the UE through dedicated control signaling, and the CG-SDT resources of different cells are different.

It should be noted that when not all data arrives, the UE can initiate the SDT process. The base station first configures a radio bearer (radio bearer, RB) for the UE that can be used to execute SDT. The RB is used to bear and transmit small packet data (that is, SDT data), and may be referred to as SDT RB in this embodiment of the application. Wherein, the SDT RB includes: at least one data radio bearer (data radio bearer, DRB), and/or, at least one signaling radio bearer (signaling radio bearer, SRB). The data carried on these SDT RBs can be transmitted through the SDT process. When data arrives on non-SDT RBs, the UE cannot initiate the SDT process. Each RB is composed of a PDCP, RLC and a logical channel (logical, LCH), and the RB is mainly used to carry data or signaling during data transmission. As shown in Figure 3, only when data arrives on RB1 or RB2, the UE can initiate the SDT process, but when data arrives on RB3, the UE cannot initiate the SDT process.

The RA-SDT solution provided in the embodiment of the present application will be described in detail below first.

First, a brief introduction to random access:

The base station sends the random access resource of the current cell to the UE through the system information, for example, the random access preamble, or the time-frequency resource for transmitting the random access preamble, that is, the random access opportunity (RA occasion, RO). The existing RA process is mainly divided into two ways: four-step random access (4-step RA) and two-step random access (2-step RA). The base station may configure four-step random access random access resources and two-step random access random access resources for the UE at the same time, or only configure any one of them. Among them, if the base station configures two random access resources for the UE at the same time, when the UE is not configured with contention free random access (CFRA) resources, the UE will use the current reference signal The relationship between the measured value of the received power (Reference Signal Receiving Power, RSRP) and the RSRP threshold configured by the base station through the system information, autonomously chooses which method of random access to initiate.

The RA-SDT process in the embodiment of the present application also includes four-step random access and two-step random access. The UE can obtain the random access resource of RA-SDT from the system information broadcast by the base station, and choose which method of random access to initiate based on the random access resource or the current value of RSRP of the UE.

Referring to Figure 4, the flow of the RA-SDT using the four-step random access method is described below:

S401: The UE sends a message 1 (message1, MSG1) to the base station. Wherein, the MSG1 includes a random access preamble (random access preamble), and the UE can notify the base station of the random access request of the UE through the random access preamble.

In some embodiments, the base station may learn that the intention of the UE to send the current random access preamble is that the UE wants to initiate SDT. In other words, the UE may send the random access preamble by using the random access resources corresponding to the SDT characteristics configured by the base station. , to notify the base station of the UE's SDT intention, so that the base station can prepare to receive small packet data. Optionally, the random access resource corresponding to the SDT characteristic may include: a random access preamble corresponding to the SDT characteristic configured by the base station, or a random access opportunity corresponding to the SDT characteristic configured by the base station, and the like.

S402: The base station sends a random access response (random access response, RAR) (also called message 2 (message2, MSG2)) to the UE in response to the random access preamble.

The UE starts the RAR time window after sending MSG1, and monitors the RAR sent by the base station within the RAR time window. If the RAR is not received within the RAR time window, it means that the random access failed, and the UE will re-initiate the random access process. .

In addition, compared with the normal four-step random access procedure, if the base station obtains the intention of the UE to initiate SDT in S401, the base station can allocate a larger uplink grant (uplink grant, UL grant) resource, so that UE can send small packet data in MSG3.

S403: Based on the uplink grant resource (UL grant) scheduled by the RAR, the UE sends MSG3 to the base station. Wherein, the MSG3 carries uplink packet data. In addition, the MSG3 also carries an RRC request message, such as an RRCResumeRequest message, which is used for requesting to resume the RRC connection, or for initiating an SDT process.

Wherein, the RRC request message may include information such as the identity of the UE. The identifier of the UE may be a unique identifier assigned to the UE by the core network, or an I-RNTI of the UE, and the like.

In some embodiments, the base station may not be able to know the SDT intention of the UE through the random access resource used by the UE in S401. At this time, the UE may carry a buffer status report (buffer status report, BSR) in this step, so that the base station indirectly Obtain the SDT intent of the UE. For example, the random access resources configured by the base station do not include SDT-dedicated resources, but the base station indicates support for SDT in the system information. At this time, the UE can use non-SDT-dedicated random access resources to initiate random access, but the UE can be in MSG3 Send the BSR to the base station to let the base station know that the current UE has a small packet of data waiting to be transmitted.

S404: The base station sends a UE contention resolution (contention resolution) message (that is, message 4 (message4, MSG4)) to the UE.

The MSG4 includes contention resolution MAC control information element (control element, CE) (that is, UE contention resolution Identity MAC CE). After receiving the message 4, the UE can judge whether the UE contention resolution Identity MAC CE is consistent with MSG3; when the judgment is consistent, the UE considers the random access process to be successful.

S405: In response to the RRC request message in MSG3, the base station may also send an RRC response message, such as an RRC Release message, to the UE. The RRCRelease message may carry a next hop chaining count (NCC) used for encrypting small packet data when the UE initiates the SDT process next time.

The UE can know the success of the SDT process through the RRC response message. In addition, the UE may continue to remain in an inactive state.

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

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

Referring to FIG. 5, the flow of the RA-SDT using the two-step random access method will be described below.

S501: The UE sends the MSGA to the base station. Wherein, the MSGA includes the contents of MSG1 and MSG3 in the four-step random access method shown in FIG. 4 , that is, the random access preamble (random access preamble), RRC request message and uplink packet data. For example, the RRC request message is an RRCResumeRequest message, which is used to request to resume the RRC connection, or to initiate the SDT process.

Wherein, the transmission resource used by the UE to send the MSGA may be obtained from system information broadcast by the base station.

Similar to S401, in some embodiments, the base station may know that the intention of the UE to send the current random access preamble is that the UE wants to initiate SDT, that is, the UE may send the random access preamble by using the random access resource corresponding to the SDT configured by the base station , to notify the base station of the UE's SDT intention, so that the base station can prepare to receive small packet data.

In some embodiments, the base station may not be able to know the SDT intention of the UE through the random access resources used by the UE in S501. At this time, the UE may carry a buffer status report (buffer status report, BSR) in this step, so that the base station indirectly Obtain the SDT intent of the UE. For example, the random access resources configured by the base station do not include SDT-dedicated resources, but the base station indicates that SDT is supported in the system information. At this time, the UE can use non-SDT-dedicated random access resources to initiate random access, but the UE can be in MSGA. Send the BSR to the base station to let the base station know that the current UE has a small packet of data waiting to be transmitted.

S502: The base station sends the MSGB to the UE.

Wherein, the MSGB may include any of the following: fallback RAR (fallback RAR), backoff indication (backoff indication), or success RAR (success RAR). When MSGB includes successRAR, the successRAR includes the contention resolution (contention resolution) flag, UE considers the random access process successful; when MSGB includes fallback RAR, UE will fall back to the four-step random access method, and send a carry MSG3 of uplink small packet data.

S503: In response to the RRC request message in the MSGA, the base station may also send an RRC response message, such as an RRC Release message, to the UE. The RRC response message may carry the NCC used for encrypting small packet data when the UE initiates the SDT process next time.

The UE can know the success of the SDT process through the RRC response message. In addition, the UE may continue to remain in an inactive state.

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

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 packet data after the UE sends the uplink packet data in MSGA.

It should be noted that in practical applications, after the UE initiates the RA-SDT process shown in Figure 4 or Figure 5, it may not be able to transmit all the data to be transmitted by sending MSG3 or MSGA once.

For example, the UE initiates an RA-SDT process for an instant message. In the four-step random access RA-SDT process, the UL grant indicated by the base station in the RAR cannot accommodate all the data of the instant message; In the RA-SDT procedure of random access, 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. At this time, the UE may continue to transmit the remaining data in the instant message through a subsequent transmission (subsequent transmission).

For another example, the service currently executed by the UE will continuously generate multiple data packets, and each data packet is small packet data. During the RA-SDT initiated by the UE, after the UE transmits one or more small packets of data through MSG3/MSGA, and new packet data arrives, the UE can continue to transmit the subsequent small packet data through subsequent transmissions.

As shown in Figure 4 or Figure 5, after the UE completes conflict resolution (after transmitting MSG4 as shown in Figure 4 or after transmitting MSGB as shown in Figure 5), the UE can use the base station to dynamically schedule uplink resources for the UE to perform subsequent transmissions .

The following is a brief description of the CG-SDT solution provided by the embodiment of the present application: 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; and then receive the RRC response message sent by the base station. The UE can learn that the SDT process is successful through the RRC response message. Exemplarily, the RRC request message may be an RRCResumeRequest message, which is used for requesting to resume the RRC connection, or for initiating an SDT process. The RRC response message may be an RRC Release message.

It should be noted that based on the different characteristics and usage conditions of RA-SDT and CG-SDT, UE can use different SDT schemes in different application scenarios. Since the transmission resources of CG-SDT are configured by the base station for a specific UE and issued in dedicated control signaling, in order to ensure the transmission efficiency of the UE, the base station can also use the modulation and code scheme (MCS) and other physical Layer or channel (for example, Physical uplink shared channel (PUSCH)) parameters are adjusted to be suitable for the radio conditions of the UE. Therefore, when UE supports RA-SDT and CG-SDT, CG-SDT is preferred to transmit small packet data, and the specific process of UE initiating SDT is as follows:

When the UE in the inactive state has data to be transmitted, the UE will judge whether the conditions for initiating SDT are currently met, including:

The RRC layer of the UE judges whether the following first SDT condition is satisfied: a, the upper layers of the RRC layer (such as the NAS layer) request to restore the RRC connection; b, the UE supports SDT; c, the base station or the cell where the UE is located supports the SDT (such as the base station SDT-related parameters are broadcast in the current cell); d, the currently arriving data to be transmitted is the data carried on the SDT RB; and e, receiving a message from the MAC layer of the UE indicating that the condition for initiating SDT is met. If the RRC layer judges that the first SDT condition is satisfied, an SDT process is initiated; otherwise, an ordinary RRC connection recovery process is performed to restore the RRC connection of the UE.

Optionally, the RRC layer may first judge whether a-d in the first SDT condition is satisfied, and if so, instruct the MAC layer to judge whether the second SDT condition is satisfied; or the RRC layer may first indicate the The MAC layer judges whether the second SDT condition is met, and then synchronously judges whether the first SDT condition is met.

Wherein, the MAC layer judges whether the following second SDT condition is satisfied: the amount of uplink data to be transmitted is less than or equal to the set small packet data threshold; the current RSRP of the UE is greater than the set first RSRP threshold. If the above-mentioned second SDT condition is not satisfied, the MAC layer notifies the RRC layer that the condition for initiating SDT is not met; if the above-mentioned second SDT condition is satisfied, then the MAC layer continues to select a carrier (such as supplementary uplink (supplementary uplink, SUL) carrier, Or normal uplink (NUL) carrier), and judge the SDT scheme available on the carrier:

The MAC layer first judges whether the CG-SDT condition is satisfied (that is, judges whether the CG-SDT is available). Exemplarily, the CG-SDT condition may include: the carrier selected by the MAC layer is configured with a CG-SDT resource, and the CG-SDT resource is valid; the RSRP corresponding to at least one synchronization signal block (synchronization signal block, SSB) is higher than the set The second RSRP threshold.

If the MAC layer determines that the CG-SDT condition is satisfied, the MAC layer notifies the RRC layer that: the condition for initiating SDT is met, and the MAC layer initiates a CG-SDT process on the selected carrier.

If the MAC layer determines that the CG-SDT condition is not satisfied, the MAC layer continues to judge whether the RA-SDT condition is satisfied (that is, judges whether the RA-SDT is available). Exemplarily, the RA-SDT condition may include: whether the carrier selected by the MAC layer is configured with resources available for RA-SDT (for example, random access resources corresponding to SDT).

If the MAC determines that the RA-SDT condition is satisfied, the MAC layer notifies the RRC layer that: the condition for initiating SDT is met, and the MAC layer initiates the RA-SDT process on the selected carrier.

If the MAC layer determines that the RA-SDT condition is not met, the MAC layer notifies the RRC layer that the condition for initiating the SDT is not met.

Based on the above process of UE initiating SDT, it can be seen that when the MAC layer of the UE determines that the second SDT condition is met and RA-SDT is available, it will notify the RRC layer: the condition for initiating SDT is met, and random access is initiated, and the random access process is implemented. SDT. When the RRC layer receives the notification, the SDT process is initiated, including: the RRC layer will restore the SDT RB, and start the first timer for the timing of the SDT process. The first timer is also called an SDT failure detection timer.

It can be seen from the above introduction of features or feature combinations that the mobile communication system not only supports SDT, but also supports other features, and supports feature combinations. Moreover, before data transmission, the UE also needs to select a characteristic or a combination of characteristics, and use the characteristic or combination of characteristics to initiate a random access resource corresponding to a random access, so as to notify the base station of the characteristic or combination of characteristics selected by the UE.

However, since the MAC layer can select features or feature combinations based on various factors (selection rules specified by the base station or the protocol, or features or feature combinations supported by the UE, features or feature combinations supported by the base station, etc.), therefore, the features selected by the UE Or the characteristic combination may not include SDT; further, even if the characteristic or characteristic combination selected by the UE includes SDT, the random access resource corresponding to the characteristic or characteristic combination may not exist in the random access resources configured by the base station. The above situations will cause the MAC layer to fail to implement the RA-SDT process, and at this time, the UE falls back to the normal RRC connection recovery process. However, the RRC layer of the UE has started the first timer. During the timing of the first timer, the UE will detect the signaling or data of the base station, and the next RRC connection recovery can only be attempted after the first timer expires. process. Since the UE starts a wrong timer, this will not only increase the power consumption of the UE, but also adversely affect the data transmission delay.

It should be noted that, in some embodiments, the timing duration of the first timer may be longer than the timing duration of the second timer (eg T319 ) used for timing the normal RRC connection recovery process. This results in a relatively long timer used by the UE in the normal RRC connection recovery process, further adversely affecting the UE's power saving and data transmission delay. For example, if the UE uses the first timer when the SDT process is not actually initiated, the base station does not send the RRC response message to the UE after the UE transmits the RRC request message, and the UE needs to wait for the duration of the first timer , and because the duration of the first timer is longer than the duration of the second timer, the UE increases the monitoring time, which is not conducive to the UE to save power consumption. In addition, if the UE has data to send at this time, the UE needs to wait for the first timer to expire before initiating the RRC connection recovery process again, and because the duration of the first timer is longer than the duration of the second timer, the UE's downlink The delay of a data transmission is affected.

In some other embodiments, the timing duration of the first timer may be shorter than the timing duration of the second timer (such as T319) used for timing the normal RRC connection recovery process. This causes the timer duration used by the UE in the RRC connection recovery process to be relatively short, and the base station decides how to send the RRC response message to the UE based on the duration of the second timer, which causes the base station to send the RRC response message to the UE. The UE no longer listens to the RRC response message sent by the base station, for example, the UE is about to initiate the next RRC connection recovery process, which leads to waste of air interface resources and/or signaling.

For example, a redcap UE currently has uplink data, and when the UE determines that the first SDT condition is met and RA-SDT is available, the UE restores the SDT RB and starts the first timer. However, the characteristics or characteristics finally selected by the UE are combined into redcap characteristics. For example, the base station does not broadcast the characteristics of redcap characteristics + SDT characteristics combined with available resources. At this time, the UE cannot continue to perform the RRC connection recovery process corresponding to the SDT characteristics, but It is necessary to perform a normal RRC connection recovery process through the random access process corresponding to the redcap feature, and then transmit the uplink data after recovering the RRC connection of the UE. Therefore, the UE does not actually perform the SDT process, and the SDT RB recovered for the SDT process and the first timer enabled are not applicable to subsequent procedures.

For another example, when the UE has uplink data to be sent during the execution of a service corresponding to slicing, and the UE determines that the first SDT condition is met and RA-SDT is available, the UE restores the SDT RB and starts the first timer. Before the data, the first characteristic or characteristic combination selected by the UE is the slicing characteristic+SDT characteristic. However, when the UE selects the random access resource, it determines that the base station does not configure the random access resource corresponding to the slicing feature + the SDT feature, but only configures the random access resource corresponding to the slicing feature. Therefore, the UE can use the second feature or a combination of features (That is, the slicing feature) The corresponding random access resource initiates random access, and performs a normal RRC connection restoration process, so as to restore the RRC connection of the UE before transmitting the uplink data. Similarly, the UE does not actually perform the SDT process, and the SDT RB recovered for the SDT process and the first timer enabled are not applicable to subsequent processes.

It should be noted that the "UE selection feature or feature combination" involved in the description of the embodiment of the present application may be performed after the UE restores the SDT RB and starts the first timer before selecting random access resources; It is performed when selecting random access resources, and the descriptions of various embodiments of the present application do not limit this. Exemplarily, the UE may learn the characteristics or combination of characteristics supported by the current cell/base station according to at least one characteristic or combination of characteristics in the received system information and corresponding random access resources.

Before introducing the embodiments of the present application, the first timer and the second timer involved in the various embodiments of the present application will be introduced.

The first timer is started when the UE initiates the SDT process, for example, started by the RRC layer of the UE, and is used to detect whether the SDT process is successful. Therefore, the first timer is also called the SDT failure detection timer. Since the SDT process is initiated when the UE is in an inactive state, when performing the SDT process, the UE will perform the RRC connection recovery process, that is, when the UE transmits an RRC request message (such as an RRCResumeRequest message) to the base station, the UE starts the first The timer, that is, the first timer starts timing. If the UE receives an RRC response message (such as RRCRelease message) fed back by the base station during the timing of the first timer, the UE may stop the first timer and determine that the SDT process is successful. If the first timer expires, the UE may determine that the current SDT process fails, and the UE may enter an idle state.

The second timer is started when the UE initiates a normal RRC connection recovery process, for example, started by the RRC layer of the UE, and is used to detect whether the RRC connection recovery process is successful. The timer is also called T319. When the UE transmits an RRC request message (such as an RRCResumeRequest message) to the base station, the UE starts a second timer, that is, the second timer starts counting. If during the timing of the second timer, the UE receives an RRC response message fed back by the base station (for example, RRCResume message, RRCSetup message, RRCRelease message, or RRCRelease with suspend indication message, etc.), the UE may stop all Describe the first timer. When the RRC response message fed back by the base station is an RRCResume message, the UE determines that the RRC connection recovery process is successful, and the UE can resume the RRC connection; when the RRC response message fed back by the base station is a RRCRelease message, or RRCRelease with suspend indication message, etc., the UE can determine that the RRC connection recovery process fails this time, and the UE cannot enter the RRC connection state. If the second timer expires, the UE may determine that the current RRC connection recovery process fails, and the UE cannot recover the RRC connection.

In some embodiments, the UE may determine a characteristic or a combination of characteristics in the following manner. There is currently data arriving, and the UE knows its current UE type, and the UE knows the characteristics or combination of characteristics supported by itself and the base station. At this time, the UE can determine the conditions corresponding to the characteristics. For example, the UE can determine whether the currently arriving data is data corresponding to the slicing characteristic, and can also determine whether the currently arriving data meets the small packet data transmission conditions. It can also determine the current coverage based on the current RSRP In some cases, based on the above factors, the UE may determine the first characteristic or combination of characteristics. At this time, the UE may determine whether the characteristic or the random access resource corresponding to the characteristic combination broadcast by the base station includes the first characteristic or the random access resource corresponding to the characteristic combination. If included, the feature or feature combination currently selected by the UE is the first feature or feature combination. If not, the UE needs to reselect the second characteristic or combination of characteristics based on the set selection rules, and judge whether the random access resource corresponding to the characteristic or combination of characteristics broadcast by the base station includes the random access resource corresponding to the second characteristic or combination of characteristics , and finally the UE can determine the selected feature or feature combination. In some embodiments, the UE may be replaced by a MAC layer or an RRC layer.

In the case that the UE does not implement the SDT process, in order to avoid the adverse impact on the power consumption and data transmission delay of the UE caused by starting the wrong timer, the embodiment of the present application provides some communication methods, which can be applied to Fig. 1 In the mobile communication system shown, the method provided by the embodiment of the present application will be described in detail below with reference to the flowcharts shown in FIGS. 6-8 . It should be noted that, in the embodiment of the present application, the UE supports two SDT schemes, CG-SDT and RA-SDT, as an example. The first SDT condition, the second SDT condition, the CG-SDT condition, and the RA-SDT condition involved in the embodiment of the present application all follow the concepts in the above-mentioned process of UE initiating SDT, and the following embodiments will not describe in detail. In addition, in the embodiment of the present application, when the RRC layer of the UE judges whether the first SDT condition (a-e) is satisfied, it is assumed that the conditions a-d are all satisfied.

Referring to the flow chart shown in FIG. 6, a communication method provided in the embodiment of the present application will be described below. It should be noted that in the embodiment of the present application, the MAC layer of the UE performs the step of selecting a feature or combining features.

S601: When the UE has a demand for uplink data transmission, the MAC layer of the UE judges whether a second SDT condition is satisfied.

Optionally, when the uplink data arrives at the RRC layer of the UE, the RRC layer instructs the MAC layer to judge whether the second SDT condition is satisfied, and synchronously judge a-d in the first SDT condition; or when the uplink When data arrives at the RRC layer, the RRC layer first judges a-d in the first SDT condition, and instructs the MAC layer to judge whether the second SDT condition is satisfied when the judgment conditions a-d are all satisfied.

When the MAC layer determines that the second SDT condition is not satisfied, the UE performs steps S602-S603; when the MAC layer determines that the second SDT condition is satisfied, the UE performs steps S604-S614.

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, where the first message is used to indicate that the condition for initiating the SDT is not met.

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.

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

Wherein, the second timer is used for timing the normal RRC connection recovery process.

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

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

At least one feature or feature combination supported by the UE, setting selection rules, at least one feature or feature combination supported by the base station, at least one feature or feature combination configured by the base station corresponding to random access resources, The transmission requirements of the UE (such as the characteristics of the currently arriving uplink data or the transmission delay), the services performed by the UE, and the current coverage status of the UE, etc.

Wherein, the setting selection rule may be configured by the base station through system information or other broadcast information, or stipulated by a protocol, which is not limited in this application. For example, the set selection rule includes the priority of characteristics or combination of characteristics. The at least one characteristic or combination of characteristics supported by the base station may be notified by the base station through system information, or determined by the UE according to at least one characteristic or combination of characteristics configured by the base station and corresponding random access resources, This application is not limited to this.

Optionally, the MAC layer may also select a feature or a combination of features with reference to the feature or combination of features preferred by the UE. Exemplarily, the UE (such as the MAC layer or the RRC layer, which may also be other protocol layers) may be based on at least one feature or feature combination supported by the base station, or at least one feature or feature combination configured by the base station corresponding to The preferred characteristic or combination of characteristics is determined by randomly accessing resources, and the preferred characteristic or combination of characteristics may also be determined according to at least one characteristic or combination of characteristics supported by the UE. For example, how to determine a preferred characteristic or combination of characteristics may refer to the above description of how to select a characteristic or a combination of characteristics.

In an embodiment, in order to ensure that there is a characteristic selected by the MAC layer in the random access resources configured by the base station or a characteristic combined with a corresponding random access resource, the MAC layer may be based on at least one characteristic or characteristic combined with the corresponding random access resource configured by the base station. Random access resources (optionally, other factors in the above description may also be combined) to select a feature or a combination of features.

Optionally, in S6032, when there is a characteristic selected by the MAC layer in the random access resource configured by the base station or a characteristic combined with the corresponding random access resource, the MAC layer uses the random access resource to initiate random access; when When the random access resource configured by the base station does not have the random access resource corresponding to the characteristic or the combination of characteristics, the MAC layer may use ordinary random access resources (corresponding to all the characteristics or the combination of characteristics configured by the base station) different random access resources) to initiate random access; or when the characteristic does not exist in the random access resources configured by the base station or the characteristic is combined with the corresponding random access resource, the MAC layer can select another characteristic or characteristic combined, and use the other feature or the feature in combination with the corresponding random access resource to initiate random access. Optionally, the characteristic or combination of characteristics reselected by the MAC layer has a lower priority than the characteristic or combination of characteristics selected last time. Optionally, when the MAC layer reselects a feature or feature combination, it may not select a feature or feature combination with a lower priority in the previously selected feature or feature combination, and may select a previously selected feature or feature combination with priority A higher-level feature or combination of features. Optionally, the previously selected feature or feature combination includes the reselected feature or feature combination. Exemplarily, the MAC layer may select the 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 characteristic or characteristic combination, the MAC layer may select a second characteristic or characteristic combination: redcap characteristic, and use the second characteristic or characteristic combination to correspond to random access resources The access resource initiates random access.

After the UE recovers the RRC connection with the base station by performing a normal RRC connection recovery process, the UE can send the uplink data to the base station.

S604: When the MAC layer determines that the second SDT condition is satisfied, the MAC layer continues to judge whether the CG-SDT condition is satisfied.

When the MAC layer determines that the CG-SDT condition is satisfied, perform S605-S606; when the MAC layer determines that the CG-SDT condition is not satisfied, perform S607-S614.

S605: When the MAC layer determines that the CG-SDT condition is met, the MAC layer sends a second message to the RRC layer. Wherein, the second message is used to indicate that a condition for initiating the SDT is met. In some embodiments, the second message may also indicate that the CG-SDT condition is met (that is, the CG-SDT solution is available).

S606: After the RRC layer receives the second message from the MAC layer, (assuming that the RRC layer determines that the first SDT condition is satisfied), the UE performs an SDT process (that is, an RRC connection recovery process for SDT ). MAC layer In this process, the MAC layer executes the CG-SDT process.

In S606, the UE may use a traditional SDT process to execute. Optionally, in this step, the RRC layer may restore the SDT RB, and start a first timer to initiate the SDT process. Wherein, the SDT RB is an RB used to execute SDT. Optionally, the SDT RB may be configured by the base station.

During the timing of the first timer, the MAC layer may execute a CG-SDT process. Before transmitting data, the MAC layer can select a feature or a combination of features (for the specific selection process, refer to the description in S6032), and then select the available CG-SDT resources for the feature or feature combination in the CG-SDT resources configured by the base station , and use the selected CG-SDT resource to transmit the uplink data (uplink small packet data) and RRC request message carried on the SDT RB. Exemplarily, the RRC request message may be an RRCResumeRequest message, which is used for requesting to resume the RRC connection, or for initiating an SDT process.

For example, the currently arriving uplink data is the data of a certain high-priority service corresponding to slicing, and the UE judges that the first SDT condition is satisfied, at this time, the UE can transmit the uplink data through the CG-SDT resource (optionally, it can also transmit RRC request message). The base station may determine that the uplink data is small-packet data through the CG-SDT resource, and recognize that the current transmission is the service data of the service corresponding to slicing through the identifier of the logical channel carrying the uplink data. Therefore, the base station can recognize that what is currently being transmitted is the small packet data of the service corresponding to slicing through the identifier of the logical channel carrying the uplink data and the CG-SDT resource. Wherein, there is an association relationship between the slicing and the logical channel.

For another example, the currently arriving uplink data is the data of the redcap UE, and the redcap UE judges that the first SDT condition is satisfied, at this time, the redcap UE can transmit the uplink data through the CG-SDT resource (optionally, it can also transmit the RRC request message). The base station can identify that the current transmission is the small packet data of the redcap UE through the CG-SDT resource. It can be understood that, due to the limited bandwidth capability of the redcap UE, the base station specially configures available CG-SDT resources for the redcap UE; The I-RNTI of the redcap UE in the RRC request message identifies that the current transmission is the small packet data of the redcap UE.

For another example, the currently arriving uplink data is the data of a high-priority service corresponding to a certain slicing of the redcap UE, and the redcap UE judges that the first SDT condition is currently satisfied, at this time, the redcap UE can transmit the uplink data through the CG-SDT resource Data (optionally, an RRC request message may also be transmitted). The base station can use the CG-SDT resource or the I-RNTI of the redcap UE in the RRC request message to identify that the current transmission is the small packet data of the redcap UE; What is transmitted is the business data of the business corresponding to slicing. Therefore, the base station can identify that the current transmission is the small packet data of the slicing service of the redcap UE.

In this embodiment of the present application, when the UE selects to transmit the small packet data of a certain characteristic or combination of characteristics through the CG-SDT resource, it may implicitly represent the selection of the characteristic or combination of characteristics on behalf of the UE.

S607: When the MAC layer determines that the CG-SDT condition is not satisfied, the MAC layer continues to judge whether the RA-SDT condition is satisfied.

When the MAC layer determines that the RA-SDT condition is satisfied, perform S608-S612; when the MAC layer determines that the RA-SDT condition is not satisfied, perform S613-S614.

S608: When the MAC layer determines that the RA-SDT condition is satisfied, the MAC layer selects a first characteristic or a combination of characteristics, and determines whether the first characteristic or a combination of characteristics satisfies a third SDT condition. Wherein, the third SDT condition is used to determine whether the selected characteristic or characteristic combination can realize SDT.

In one embodiment, similar to the description in S6032, the MAC layer may select the first characteristic or a combination of characteristics based on multiple factors, for example, the MAC layer may but not limited to at least one or a combination of the following , select the first feature or feature combination:

At least one characteristic or combination of characteristics supported by the UE, setting selection rules, at least one characteristic or combination of characteristics supported by the base station, characteristics or combination of characteristics configured by the base station corresponding to random access resources, the UE The transmission requirements of the UE (such as the characteristics or transmission delay of the currently arriving uplink data), the services performed by the UE, the current coverage status of the UE, the characteristics or combination of characteristics preferred by the UE, etc.

Wherein, the setting selection rule may be configured by the base station through system information or other broadcast information, or stipulated by a protocol, which is not limited in this application. For example, the set selection rule includes the priority of characteristics or combination of characteristics. The at least one characteristic or combination of characteristics supported by the base station may be notified by the base station through system information, or determined by the UE according to at least one characteristic or combination of characteristics configured by the base station and corresponding random access resources, This application is not limited to this.

Exemplarily, when the MAC layer selects a characteristic or a combination of characteristics according to actual conditions or requirements such as transmission requirements of the UE and/or services performed by the UE, the characteristics or combination of characteristics may include SDT characteristics, but , the random access resource configured by the base station does not necessarily have the random access resource corresponding to the characteristic or characteristic combination.

For another example, when the MAC layer selects a characteristic or a combination of characteristics according to at least one characteristic or combination of characteristics supported by the base station and/or a set selection rule configured by the base station, the random access resource configured by the base station may have all The characteristic or combination of characteristics corresponds to random access resources, but the characteristic or combination of characteristics does not necessarily include the SDT characteristic.

To sum up, in this embodiment, since the first feature or feature combination selected by the MAC layer may or may not include the SDT feature; the first feature may exist in the random access resources configured by the base station or a random access resource corresponding to the characteristic combination, or there may be no random access resource corresponding to the first characteristic or the characteristic combination. Therefore, in this embodiment, the third SDT condition includes: the selected characteristic or characteristic combination includes SDT, and the random access resources corresponding to the selected characteristic or characteristic combination exist in the random access resources configured by the base station .

In another embodiment, in order to ensure that there is a random access resource selected by the MAC layer in the random access resources configured by the base station or a combination of characteristics corresponding to the random access resources, the MAC layer may be based on at least one characteristic or combination of characteristics configured by the base station. The corresponding random access resource (optionally, other factors in the above description may also be combined) is used to select the first characteristic or combination of characteristics.

In this implementation manner, the first feature or feature combination selected by the MAC layer may include SDT, or may not include the SDT feature. Therefore, the third SDT condition includes: the selected feature or combination of features includes SDT.

In yet another embodiment, in order to ensure that the feature or feature combination selected by the MAC layer includes the SDT feature, the MAC layer may base on the transmission requirements of the UE, the services performed by the UE, and the current coverage of the UE. At least one of the statuses to select the first feature or combination of features.

In this embodiment, the random access resources corresponding to the first characteristic or combination of characteristics may exist in the random access resources configured by the base station, or may not exist in 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 have a selected characteristic or a characteristic combined with a corresponding random access resource.

When the MAC layer determines that the selected feature or feature combination does not meet the third SDT condition, the UE performs S609-S610; when the MAC layer determines that the selected feature or feature combination meets the third SDT condition , the UE performs S611-S612.

In one embodiment, when the MAC layer determines that the currently selected first feature or feature combination does not satisfy the third SDT condition (for example, there is no first feature or feature combination corresponding to the random access configured by the base station). random access resources), the MAC layer may also re-execute S608, select the second feature or feature combination, and judge whether the second feature or feature combination satisfies the third SDT condition, and for the second feature or feature combination Follow up procedure.

Optionally, the priority of the second characteristic or combination of characteristics is lower than that of the first characteristic or combination of characteristics. Optionally, when the MAC layer reselects a feature or feature combination, it may not select a feature or feature combination with a lower priority in the previously selected feature or feature combination, and may select a previously selected feature or feature combination with priority A higher-level feature or combination of features. Optionally, the first feature or feature combination includes features in the second feature or feature combination, for example, the first feature or feature combination includes: redcap UE feature + SDT feature, when the MAC When the layer determines that there is no random access resource corresponding to the first characteristic or characteristic combination, the MAC layer may select the second characteristic or characteristic combination: redcap UE characteristic, and use the second characteristic or characteristic combination corresponding random access resources to initiate random access.

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, where the third message is used to indicate that the condition for initiating the SDT is not met.

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.

S6101: Same as S6031 in S603.

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

Similar to S6032, the difference is that the MAC layer does not select a feature or feature combination in this step. In this step, when the first characteristic selected by the MAC layer or the characteristic combined with the corresponding random access resource exists in the random access resource configured by the base station, the MAC layer uses the random access resource to initiate random access; when the When there is no random access resource corresponding to the first characteristic or characteristic combination in the random access resources configured by the base station, the MAC layer may use ordinary random access resources (combined with all characteristics or characteristics configured by the base station The corresponding random access resources are different) to initiate random access, or use the second characteristic or the characteristic in combination with the corresponding random access resource to initiate random access.

S611: When the MAC layer determines that the third SDT condition is met, the MAC layer sends a fourth message to the RRC layer, where the fourth message is used to indicate that a condition for initiating an SDT is met. Optionally, the fourth message may also indicate that the RA-SDT condition is met (that is, the RA-SDT scheme is available).

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

S6121: The RRC layer restores the SDT RB, and starts a first timer to initiate the SDT process.

The SDT RB is an RB used to execute SDT, as shown in Figure 3. Optionally, the SDT RB may be configured for the base station.

S6122: During the timing process of the first timer, the MAC layer executes the RA-SDT process (that is, performs random access including SDT), that is, the MAC layer initiates random access, and during the random access process Implementing SDT in , including: the MAC layer initiates random access (sends MSG1 or MSGA) using selected characteristics or characteristics in conjunction with corresponding random access resources; and carries the uplink in MSG3 or MSGA during the random access process data. Wherein, the uplink data is carried in the SDT RB.

For the specific process of performing RA-SDT at the MAC layer in S612, reference may be made to FIG. 4 or FIG. 5 , which will not be repeated here. Through S612, the UE may send uplink data to the base station during the random access process.

S613: When the MAC layer determines that the RA-SDT condition is not satisfied, the MAC layer sends a fifth message to the RRC layer, where the fifth message is used to indicate that the condition for initiating the SDT is not satisfied.

S614: Same as S603, that is, S6141-S6142 can refer to the description in S6031 and S6032, and will not be repeated here.

The embodiment shown in FIG. 6 provides a communication method. In this method, after the MAC layer of the UE determines that the second SDT condition is met and selects a characteristic or a combination of characteristics, it then judges whether the second SDT condition is satisfied according to the selected characteristic or a combination of characteristics. Three SDT conditions, and then notify the RRC layer whether the result meets the conditions for initiating SDT. This method can avoid the phenomenon that the RRC layer wrongly starts the first timer when the MAC layer cannot realize the SDT process, and then avoids the adverse impact caused by wrongly starting the first timer on power consumption and data transmission delay or Problems that lead to waste of air interface resources and/or signaling. Therefore, the method can ensure reduction of UE power consumption and data transmission delay, or reduce waste of air interface resources and/or signaling.

Next, referring to the flowchart shown in FIG. 7 , another communication method provided by the embodiment of the present application will be described. It should be noted that in the embodiment of the present application, the RRC layer of the UE performs the step of selecting a feature or combining features.

S701: When the UE has a demand for uplink data transmission, the MAC layer of the UE judges whether a second SDT condition is satisfied.

For the timing of performing S701 at the MAC layer, reference may be made to the description in S601 in the embodiment shown in FIG. 6 , which will not be repeated here.

When the MAC layer determines that the second SDT condition is not satisfied, the UE performs steps S702-S703; when the MAC layer determines that the second SDT condition is satisfied, the UE performs steps S704-S714.

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, where the first message is used to indicate that the condition for initiating the SDT is not met.

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.

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

Wherein, the second timer is used for timing the normal RRC connection recovery process.

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

Optionally, before the MAC layer executes S7032, the RRC layer may also select a feature or feature combination. In this embodiment, the specific steps for the RRC layer to select a feature or feature combination can refer to the description of the MAC layer selection feature or feature combination in S6032 in the embodiment shown in FIG. 6 , which will not be repeated here.

In an embodiment, after the RRC layer selects a characteristic or a combination of characteristics, it may also determine whether there is a random access resource corresponding to the characteristic or a combination of characteristics in the random access resources configured by the base station; when the RRC layer When determining that there is a random access resource corresponding to the characteristic or characteristic combination among the random access resources configured by the base station, the RRC layer may notify the MAC layer of the random access resource or the characteristic or characteristic combination, So that the MAC can directly initiate random access according to the random access resource when executing S7032. When the RRC layer determines that there is no random access resource corresponding to the characteristic or characteristic combination in the random access resources configured by the base station, the RRC layer may instruct the MAC layer to initiate a normal random access, so that When performing S7032, the MAC layer may directly select a common random access resource to initiate random access; or the RRC layer may also reselect another feature or a combination of features, so that the MAC layer can use the other The characteristic or the characteristic in combination with the corresponding random access resource initiates random access.

After the UE recovers the RRC connection with the base station by performing a normal RRC connection recovery process, the UE can send the uplink data to the base station.

S704: When the MAC layer determines that the second SDT condition is satisfied, the MAC layer continues to judge whether the CG-SDT condition is satisfied.

When the MAC layer determines that the CG-SDT condition is satisfied, perform S705-S706; when the MAC layer determines that the CG-SDT condition is not satisfied, perform S707-S715.

S705: When the MAC layer determines that the CG-SDT condition is satisfied, the MAC layer sends a second message to the RRC layer. Wherein, the second message is used to indicate that a condition for initiating the SDT is met. Optionally, the second message may also indicate that the CG-SDT condition is met (that is, the CG-SDT solution is available).

S706: After the RRC layer receives the second message from the MAC layer, (assuming that the RRC layer determines that the first SDT condition is met), the UE performs an SDT process (that is, an RRC connection recovery process for SDT ). The MAC layer performs a CG-SDT process in this process.

In S706, the UE may adopt a traditional SDT process, and the specific process is similar to that of S606 in the embodiment shown in FIG. 6 , and reference may be made to each other. The difference is that before the data transmission, the RRC layer selects the characteristic or the combination of characteristics, and the specific process can also refer to the description of selecting the characteristic or the combination of characteristics 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 of the feature or feature combination, which is not made in this application limited.

S707: When the MAC layer determines that the CG-SDT condition is not satisfied, the MAC layer continues to judge whether the RA-SDT condition is satisfied.

When the MAC layer determines that the RA-SDT condition is satisfied, perform S708-S713; when the MAC layer determines that the RA-SDT condition is not satisfied, perform S714-S715.

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

S709: After the RRC layer receives the third message from the MAC layer (assuming that the RRC layer determines that the first SDT condition is satisfied), the RRC layer selects the first feature or feature combination, and judges the Whether the above-mentioned first feature or combination of features satisfies the third SDT condition. Wherein, the third SDT condition is used to determine whether the selected characteristic or characteristic combination can realize SDT.

In S709, the process of the RRC layer selecting the first feature or feature combination, and the third SDT condition may refer to the description in S608 in the embodiment shown in FIG. 6 , which will not be repeated here.

When the RRC layer determines that the third SDT condition is not satisfied, the UE performs S710-S711; when the RRC layer determines that the third SDT condition is satisfied, the UE performs S712-S713.

Optionally, the RRC layer may also reselect the second characteristic or combination of characteristics when the first characteristic or combination of characteristics does not meet the third SDT condition. For the specific process, refer to the description of reselecting characteristics or combination of characteristics at the MAC layer in S608 , which will not be repeated here.

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, where the fourth message is used to indicate initiation of non-SDT random access. It should be noted that S710 is an optional step, and the MAC layer may also determine to initiate non-SDT random access during the implementation process of the UE.

Optionally, the RRC layer may also notify the MAC layer of the currently selected feature or feature combination, or the currently selected feature or feature combination corresponding random access resources, so that the MAC layer can use the RRC selected feature or feature Random access is initiated in combination with corresponding random access resources. Optionally, the RRC layer may notify the MAC layer of the currently selected feature or feature combination, or a random access resource corresponding to the currently selected feature or feature combination through the fourth message.

S711: The UE executes a normal RRC connection recovery process, including S7111 and S7112.

S7111: Same as S7031 in S703.

S7112: During the timing of the second timer, the MAC layer performs non-SDT random access. Similar to S7032, the similarities can refer to each other. Different from S7032, before performing S7112, the RRC layer does not select the feature or feature combination, because the feature or feature combination has been selected in S709.

S712: When the RRC layer determines that the third SDT condition is met, the RRC layer sends a fifth message to the MAC layer, where the fifth message is used to indicate initiation of SDT random access. It should be noted that S712 is an optional step, and the MAC layer may also determine to initiate random access of SDT (ie, RA-SDT) during the implementation process of the UE.

Optionally, the RRC layer may also notify the MAC layer of the currently selected feature or feature combination, or the currently selected feature or feature combination corresponding random access resources, so that the MAC layer can use the RRC selected feature or feature Random access is initiated in combination with corresponding random access resources. Optionally, the RRC layer may notify the MAC layer of the currently selected feature or feature combination, or a random access resource corresponding to the currently selected feature or feature combination through the fifth message.

S713: After the RRC layer determines that the third SDT condition is satisfied (optionally, after sending the fifth message to the MAC layer), the UE executes an SDT process. For the SDT process performed by the UE in S713, reference may be made to the description in S612 in the embodiment shown in FIG.

S714: When the MAC layer determines that the RA-SDT condition is not satisfied, the MAC layer sends a sixth message to the RRC layer, where the sixth message is used to indicate that the condition for initiating the SDT is not satisfied.

S715: Same as S703, that is, S7151 and S7152 can refer to S7031 and S7032, and will not be repeated here.

The embodiment shown in Fig. 7 provides a kind of communication method, in this method, after receiving the indication that MAC layer satisfies the condition of initiating SDT, RRC layer selects characteristic or combination of characteristics, and judges whether to Satisfy the third SDT condition, and then decide whether to initiate the SDT process according to whether the third SDT condition is satisfied. This method can avoid the phenomenon that the RRC layer wrongly starts the first timer to initiate the SDT process when the MAC layer cannot realize the SDT process, and then avoids causing power consumption and data transmission delay due to wrongly starting the first timer. Adverse effects or problems that lead to waste of air interface resources and/or signaling. Therefore, the method can ensure reduction of UE power consumption and data transmission delay, or reduce waste of air interface resources and/or signaling.

Referring to the flowchart shown in FIG. 8 , a communication method provided by the embodiment of the present application will be described below. It should be noted that in the embodiment of the present application, the MAC layer of the UE performs the step of selecting a feature or combining features.

S801-S807 are the same as S601-S607 in the embodiment shown in FIG. 6, and S814-S815 are the same as S613-S614 in the embodiment shown in FIG. The difference is the steps S808-S813 after the MAC layer judges that the RA-SDT condition is satisfied, and these steps will be described in detail below.

S808: When the MAC layer of the UE determines that the RA-SDT condition is satisfied, send a third message to the RRC layer. The third message is used to indicate that the condition for initiating the SDT is met. In some embodiments, the third message may also indicate that the RA-SDT condition is satisfied (that is, the RA-SDT scheme is available).

S809: After the RRC layer receives the third message, (assuming that the RRC layer determines that the first SDT condition is met), the RRC layer restores the SDT RB, and starts a first timer to initiate an SDT process (ie RRC connection recovery procedure for SDT).

The SDT RB is an RB used to execute SDT, as shown in Figure 3. Optionally, the SDT RB may be configured by the base station.

S810: After determining that the RA-SDT condition is satisfied, the MAC layer selects a first characteristic or combination of characteristics, and determines whether the selected first characteristic or combination of characteristics satisfies a third SDT condition. Wherein, the third SDT condition is used to determine whether the selected characteristic or characteristic combination can realize SDT.

For the process of the MAC layer selecting the first feature or feature combination, and the third SDT condition, reference may be made to the description in S608 in the embodiment shown in FIG. 6 , which will not be repeated here.

When the MAC layer determines that the third SDT condition is not satisfied, the UE performs S811-S812; when the MAC layer determines that the third SDT condition is satisfied, the UE performs S813.

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, where the fourth message is used to indicate cancellation of an SDT (RA-SDT) process.

Exemplarily, the fourth message may indicate that "SDT is not initiated, or the selected feature or combination of features does not include SDT, or cancel the SDT process" and the like.

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

S8121: The RRC layer stops the first timer, and starts a second timer (T319), so as to initiate a normal RRC connection recovery process. Wherein, the second timer is used for timing the normal RRC connection recovery process.

Optionally, the RRC layer may also suspend the SDT RB.

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

In some embodiments, when there is a characteristic selected by the MAC layer in the random access resource configured by the base station or a characteristic combined with the corresponding random access resource, the MAC layer uses the random access resource to initiate random access; when the When the random access resource configured by the base station does not have the random access resource corresponding to the feature or the combination of features, the MAC layer may use a common random access resource (the random access resource corresponding to all the features or the combination of features configured by the base station) different access resources) to initiate random access, or to initiate random access by using the second feature or a feature in combination with corresponding random access resources.

S813: When the MAC layer determines that the third SDT condition is satisfied, during the running process of the first timer, the MAC layer performs an RA-SDT process (that is, performs random access including SDT), that is, the The above MAC layer initiates random access, and implements SDT during the random access process. The specific process can refer to the description in S6122 of the embodiment shown in FIG. 6 , which will not be repeated here.

The embodiment shown in FIG. 8 provides a communication method, in which, the MAC layer of the UE notifies the RRC layer to initiate the SDT process after determining that the second SDT condition is satisfied; the MAC layer can also select a characteristic or a combination of characteristics , when judging according to the characteristic or characteristic combination that the third SDT condition is not met, the MAC layer notifies the RRC layer to cancel the SDT process. Through this method, after the RRC layer initiates the SDT process and starts the first timer, when the MAC layer determines that the SDT process cannot be realized, the RRC layer can be notified to cancel the SDT process, thereby stopping the first timer, and initiating a normal RRC connection recovery process. Since the method can stop the first timer as soon as possible when the first timer is wrongly turned on, the method can avoid adverse effects on power consumption and data transmission delay caused by wrongly turning on the first timer or causing air interface Resource and/or signaling waste issues. Therefore, the method can ensure reduction of UE power consumption and data transmission delay, or reduce waste of air interface resources and/or signaling.

It should be noted that the various embodiments provided in this application do not limit the sequence of each step, nor limit each step as a mandatory step. In addition, the embodiments of the present application do not limit the names of the various messages involved, and any message may be replaced with instructions, notifications, information, and the like.

Based on the embodiment shown in FIG. 6 or FIG. 7 , the present application also provides a communication method, which can be applied to the mobile communication system as shown in FIG. 1 . The method provided by the embodiment of the present application will be described below with reference to FIG. 9 .

S901: When the UE is in an RRC inactive state, after determining that a condition for initiating an SDT is met, determine a first feature or feature combination.

Optionally, in this embodiment of the present application, the MAC layer of the UE determines whether the condition for initiating the SDT is satisfied. Optionally, the condition for initiating the SDT may include the second SDT condition and the RA-SDT condition in the above embodiments. It should be noted that the embodiment of the present application assumes that a-d in the first SDT condition is satisfied, that is, the condition a-d in the first SDT condition is no longer considered.

In an implementation manner, the UE may select the first characteristic or combination of characteristics from at least one characteristic or combination of characteristics supported by the UE and supported by the base station. Optionally, the UE may also consider at least one or a combination of the following:

Setting selection rules, characteristics configured by the base station or characteristics combined with corresponding random access resources, transmission requirements of the UE, services currently performed by the UE, coverage status of the UE, characteristics preferred by the UE, or feature combination.

Wherein, the setting selection rule may be configured by the base station through system information or other broadcast information, or stipulated by a protocol, which is not limited in this application. For example, the set selection rule includes the priority of characteristics or combination of characteristics. The at least one characteristic or combination of characteristics supported by the base station may be notified by the base station through system information, or determined by the UE according to at least one characteristic or combination of characteristics configured by the base station and corresponding random access resources, This application is not limited to this. The characteristic or combination of characteristics preferred by the UE may be determined by the UE according to at least one characteristic or combination of characteristics supported by the base station, or at least one characteristic or combination of characteristics configured by the base station to correspond to random access resources.

For a specific process for the UE to select the first feature or feature combination, reference may be made to the specific description of the MAC layer or the RRC layer selecting a feature or feature combination in the above embodiments, which will not be described in detail here.

S902: When the first characteristic or combination of characteristics includes an SDT characteristic, and random access resources corresponding to the first characteristic or combination of characteristics exist in random access resources configured by the base station, the UE performs an SDT process.

Optionally, in this embodiment of the application, the UE may perform the SDT process through the following steps A1-A2:

A1: Recover the SDT radio bearer RB and start a first timer; wherein, the first timer is used to detect whether the SDT process is successful, and the SDT RB is an RB used to execute the SDT. Optionally, the RRC layer of the UE may perform step A1, and the SDT RB may be configured by the base station.

A2: During the timing of the first timer, use the first feature or feature in conjunction with the corresponding random access resource to initiate random access, and send target data during the random access process; wherein the target data carried in the SDTRB. Optionally, the MAC layer of the UE may perform step A2.

In the first implementation manner, after the MAC layer of the UE determines that the condition for initiating the SDT is met, the MAC layer determines the first characteristic or combination of characteristics. Optionally, the MAC layer may further determine whether the first characteristic or combination of characteristics satisfies a third SDT condition.

Optionally, the MAC layer may select the first feature or feature combination with reference to the description in S608 in the embodiment shown in FIG. 6 . Optionally, the third SDT condition is used to determine whether the selected feature or combination of features can implement SDT. For a specific description, refer to the detailed description of the third SDT condition in S608, which will not be repeated this time. When the first feature or feature combination satisfies the third SDT condition, it means that the first feature or feature combination includes the SDT feature, and the first feature or feature combination corresponds to the random access resource configured by the base station. random access resources.

Optionally, when the MAC layer determines that the first feature or feature combination satisfies the third SDT condition, the MAC layer may send a first message to the RRC layer of the UE, and the first message is used for Indicates that the conditions for initiating SDT are met. After the RRC layer receives the first message, the RRC layer may perform the above step A1.

In the second implementation manner, after the MAC layer of the UE determines that the condition for initiating SDT is met, the MAC layer sends a second message to the RRC layer, and the second message is used to indicate that the condition for initiating SDT is met; The RRC layer selects the first feature or feature combination. Optionally, the RRC layer may further determine whether the first characteristic or characteristic 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 includes the SDT feature, and the first feature or feature combination corresponds to the random access resource configured by the base station. random access resources.

Optionally, the RRC layer may refer to the description in S709 in the embodiment shown in FIG. 7 to select the first feature or feature combination.

Optionally, in this embodiment, when the RRC layer determines that the first feature or feature combination includes the SDT feature, and there is a random access resource corresponding to the first feature or feature combination in the random access resource configured by the base station When resources are input, the RRC layer may perform step A1, and may 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 indicate the The MAC layer initiates the random access of the SDT. In this way, the MAC layer may execute step A2 after receiving the third message. Optionally, the RRC layer may also notify the MAC layer of the first characteristic or combination of characteristics selected, or notify the MAC layer of a random access resource used by the first characteristic or combination of characteristics. For example, the third message may also indicate the first characteristic or combination of characteristics, or indicate a random access resource corresponding to the first characteristic or combination of characteristics.

Optionally, when the first characteristic or the combination of characteristics does not include the SDT characteristic, and/or there is no random access resource corresponding to the first characteristic or the combination of characteristics in the random access resources configured by the base station, Execute the RRC connection recovery procedure. Optionally, after the UE executes the RRC connection recovery procedure, the UE may enter a connected state.

In the above first implementation manner, when the MAC layer determines that the first characteristic or combination of characteristics does not include the SDT characteristic, and/or, the random access resource configured by the base station does not have the first characteristic or When the characteristic is combined with the corresponding random access resource, the MAC layer may send a fourth message to the RRC layer, where the fourth message is used to indicate that the condition for initiating the SDT is not met. In this way, after receiving the fourth message, the RRC layer can perform a normal RRC connection recovery process.

In the above second implementation manner, when the RRC layer determines that the first characteristic or combination of characteristics does not include the SDT characteristic, and/or, the random access resource configured by the base station does not have the first characteristic or The RRC layer performs an RRC connection recovery procedure when the characteristics are combined with the corresponding random access resources.

Optionally, the RRC may initiate an RRC connection recovery process by starting a second timer.

Optionally, when the first characteristic or the combination of characteristics does not include the SDT characteristic, and/or there is no random access resource corresponding to the first characteristic or the combination of characteristics in the random access resources configured by the base station, The UE may also perform non-SDT random access through the following steps: use the first random access resource configured by the base station to initiate random access; wherein, when the random access resource configured by the base station does not exist When the first characteristic or the random access resource corresponding to the combination of characteristics, the first random access resource is the same as the second characteristic configured by the base station or the random access resource corresponding to the combination of characteristics, or the first random access resource The input is a common random access resource; when the random access resource configured by the base station has the first characteristic or a random access resource corresponding to the combination of characteristics, the first random access resource is the first The characteristics or characteristics are associated with corresponding random access resources.

Wherein, the second characteristic or combination of characteristics may be a random access resource corresponding to the first characteristic or combination of characteristics does not exist in the random access resources configured by the base station, and the RRC layer reselects A characteristic or a combination of characteristics.

Optionally, the priority of the second characteristic or combination of characteristics is lower than that of the first characteristic or combination of characteristics. Optionally, when the RRC layer reselects a feature or feature combination, it may not select a feature or feature combination with a lower priority in the previously selected feature or feature combination, and may select the previously selected feature or feature combination with priority A higher-level feature or combination of features. Optionally, the first feature or feature combination includes features in the second feature or feature combination, for example, the first feature or feature combination includes: redcap UE feature + SDT feature, the second feature The feature or combination of features contains the redcap UE feature.

Optionally, the MAC layer of the UE may perform the foregoing non-SDT random access.

Optionally, in the embodiment of the present application, the first feature or feature combination includes at least one of the following:

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

The embodiment of this application provides a communication method. In this method, after the UE meets the conditions for initiating SDT, when the selected first feature or feature combination includes the SDT feature, and the random access resource corresponding to the first feature or feature combination exists in the random access resource configured by the base station Execute the SDT process when resources are available. Compared with the traditional solution, the UE initiates the SDT process when it meets the conditions for initiating SDT. In the method provided by the embodiment of this application, the UE initiates the SDT process only when the selected feature or the combination of features can realize the SDT, so as to avoid the situation that the SDT process cannot be realized. In the case of wrongly starting the first timer to initiate the phenomenon of the SDT process, thereby avoiding the adverse impact on power consumption and data transmission delay caused by wrongly starting the first timer or causing waste of air interface resources and/or signaling question. Therefore, the method can ensure reduction of UE power consumption and data transmission delay, or reduce waste of air interface resources and/or signaling.

Based on the embodiment shown in FIG. 8 , the present application also provides a communication method, which can be applied to the mobile communication system shown in FIG. 1 . The method provided by the embodiment of the present application will be described below with reference to FIG. 10 .

S1001: When the UE is in an RRC inactive state, start an SDT process after determining that a condition for initiating an SDT is satisfied, and determine a first characteristic or a combination of characteristics.

Optionally, in this embodiment of the present application, the MAC layer of the UE determines whether the condition for initiating the SDT is satisfied. Optionally, the condition for initiating the SDT may include the second SDT condition and the RA-SDT condition in the above embodiments. It should be noted that the embodiment of the present application assumes that a-d in the first SDT condition is satisfied, that is, the condition a-d in the first SDT condition is no longer considered.

Optionally, the process for the UE to select the first feature or feature combination may refer to S901, which will not be repeated here.

S1002: When the first characteristic or characteristic combination does not include the SDT characteristic, and/or when there is no random access resource corresponding to the first characteristic or characteristic combination in the random access resources configured by the base station, cancel the Describe the SDT process.

Optionally, in this embodiment of the present application, the MAC layer may send the first message to the RRC layer when determining that a condition for initiating the SDT is met. The first message is used to indicate that the SDT condition is met. The RRC layer may start an SDT process after receiving the first message.

Optionally, the RRC layer can start the SDT process through the following steps:

Resuming the SDT radio bearer RB and starting 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;

When the MAC layer determines that the condition for initiating the SDT is met, it may further determine the first characteristic or combination of characteristics, and determine whether the first characteristic or combination of characteristics satisfies a third SDT condition. Optionally, the MAC layer may select the first feature or feature combination with reference to the description in S608 in the embodiment shown in FIG. 6 . Optionally, the third SDT condition is used to determine whether the selected feature or combination of features can implement SDT. For a specific description, refer to the detailed description of the third SDT condition in S608, which will not be repeated this time. When the first feature or feature combination satisfies the third SDT condition, it means that the first feature or feature combination includes the SDT feature, and the first feature or feature combination corresponds to the random access resource configured by the base station. and when the first characteristic or combination of characteristics does not satisfy the third SDT condition, it means that: the first characteristic or combination of characteristics does not include the SDT characteristic, and/or the random access resource configured by the base station There is no random access resource corresponding to the first characteristic or characteristic combination in the access resources.

In an embodiment, when the MAC layer determines that the first feature or feature combination does not include the SDT feature, and/or, the first feature or feature combination does not exist in the random access resources configured by the base station When corresponding random access resources, the MAC layer may send the second message to the RRC layer. After receiving the second message, the RRC layer cancels the SDT process. Wherein, the second message is used to notify the RRC layer to cancel the SDT process. Optionally, the RRC layer may cancel the SDT process through the following steps, including:

The RRC layer stops the first timer, and/or, the RRC layer suspends the SDT RB.

In this embodiment, when the first characteristic or characteristic combination does not include the SDT characteristic, and/or, there is no random access resource corresponding to the first characteristic or characteristic combination in the random access resources configured by the base station When , the method further includes: performing an RRC connection restoration process.

Optionally, the RRC layer may start a second timer to initiate the RRC connection recovery procedure.

Optionally, during the RRC connection recovery process, the MAC layer may perform non-SDT random access through the following steps: use the first random access resource configured by the base station to initiate random access; wherein, when the When the random access resource corresponding to the first characteristic or combination of characteristics does not exist in the random access resources configured by the base station, the first random access resource and the random access resource corresponding to the second characteristic or combination of characteristics configured by the base station The access resources are the same, or the first random access is a common random access resource; when the first characteristic or characteristic is combined with the corresponding random access resource in the random access resource configured by the base station, the The first random access resource is a random access resource corresponding to the first characteristic or characteristic combination.

Wherein, the second characteristic or combination of characteristics may be reselected by the MAC layer when there is no random access resource corresponding to the first characteristic or combination of characteristics in the random access resources configured by the base station. A characteristic or a combination of characteristics. Optionally, the priority of the second characteristic or combination of characteristics is lower than that of the first characteristic or combination of characteristics. Optionally, when the MAC layer reselects a feature or feature combination, it may not select a feature or feature combination with a lower priority in the previously selected feature or feature combination, and may select a previously selected feature or feature combination with priority A higher-level feature or combination of features. Optionally, the first feature or feature combination includes features in the second feature or feature combination, for example, the first feature or feature combination includes: redcap UE feature + SDT feature, the second feature The feature or combination of features contains the redcap UE feature.

In another embodiment, when the first characteristic or combination of characteristics selected by the MAC layer includes an SDT characteristic, and random access resources corresponding to the first characteristic or combination of characteristics exist in the random access resources configured by the base station When accessing resources, during the timing process of the first timer, the MAC layer uses the first characteristic or characteristics in combination with the corresponding random access resource to initiate random access, and sends the target Data; wherein, the target data is carried in the SDT RB. Refer to FIG. 4 or FIG. 5 for the process of performing random access at the MAC layer, which will not be repeated here.

Optionally, in the embodiment of the present application, the first feature or feature combination includes at least one of the following:

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

The embodiment of this application provides a communication method. In this method, the UE may initiate the SDT process when the condition for initiating SDT is met; then when the first feature or feature combination selected by the UE does not include the SDT feature, and/or, the random access resources configured by the base station When there is no random access resource corresponding to the first characteristic or characteristic combination, cancel the SDT process. Because this method can cancel the SDT process in time when the characteristics or combination of characteristics selected by the UE cannot realize SDT, and furthermore, this method can stop the first timer as soon as possible when the first timer is started by mistake, so as to avoid Enabling the first timer has adverse effects on power consumption and data transmission delay, or causes waste of air interface resources and/or signaling. Therefore, the method can ensure reduction of UE power consumption and data transmission delay, or reduce waste of air interface resources and/or signaling.

Based on the embodiments shown in FIG. 8 and FIG. 10 , the present application also provides an embodiment of a communication method. In the embodiment of the present application, it is assumed that the selection of a feature or a combination of features is performed by the MAC layer. The solution provided by 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 the first information to the upper layer (such as the RRC layer), and the first information indicates "SDT is not initiated, or the selected feature or combination of features does not include SDT, or cancels the SDT process", etc. The RRC layer suspends the SDT RB (optional); the RRC layer stops the first timer and starts the second timer (such as T319), and the second timer initiates a normal RRC connection recovery process for the UE (for example, when sending RRCResumeRequest) The timer that needs to be turned on. It should be noted that this embodiment is a specific example of the embodiment shown in FIG. 8 or FIG. 10 , therefore, the same or corresponding steps may refer to each other.

Based on the above description, a specific data transmission process is now taken as an example. Assuming that the current redcap UE has data transmission requirements, see Figure 11 for the detailed process. The order of each step in FIG. 11 is not limited, nor is each step must be a mandatory step. In addition, the redcap UE feature can be replaced by other features or feature combinations, which is not limited in this application.

S1101: When the uplink data arrives at the SDT RB of the UE, the MAC layer of the UE judges whether the second SDT condition is satisfied. If yes, execute S1105; otherwise, execute S1102.

Optionally, when the UE has a demand for uplink data transmission, the UE judges whether a condition for initiating SDT (for example, an RRC connection recovery process for SDT) is met. For example, the RRC layer of the UE judges whether the first SDT condition is satisfied, and the MAC layer of the UE judges whether the second SDT condition is satisfied. In the embodiment of the present application, a-d in the first SDT condition is satisfied as an example for illustration. When judging whether the second SDT condition is satisfied, the UE executes S1102 if the second SDT condition is not satisfied, and executes S1105 if the second SDT condition is satisfied.

S1102: When the MAC layer determines that the second SDT condition is not met, it indicates that the upper layer (the subsequent description of this application takes the RRC layer as an example) does not meet the condition for initiating the SDT.

In some embodiments, the UE (for example, the MAC layer) may also continue to perform feature selection or feature combination after judging that the condition for initiating the SDT is not satisfied. At this time, in addition to indicating to the upper layer that the condition for initiating the SDT is not met, the selected feature or combination of features may also be indicated.

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

Here, the ordinary RRC recovery process can be understood as performing data transmission after entering the RRC connection state.

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

It should be noted that the present application does not limit the sequence of S1103 and S1104.

S1105: When the MAC layer determines that the second SDT condition is met, continue to judge whether the CG-SDT condition is met. If it is satisfied, execute S1106; otherwise, execute S1109.

S1106: When the MAC layer determines that the CG-SDT condition is met, instruct the RRC layer to meet the condition for initiating the SDT.

S1107: The RRC layer initiates an SDT process. Optionally, the RRC layer may restore the SDT RB, and start the first timer.

S1108: The MAC layer executes a CG-SDT process. Optionally, the MAC layer may select a characteristic or a combination of characteristics before data transmission. Optionally, the feature or combination of features selected by the MAC layer includes the SDT feature.

Through S1106-S1108, the UE can choose to transmit small packet data through CG-SDT. For example, the UE may use the CG-SDT resource to transmit the small packet data including the characteristics of the SDT characteristics or a combination of characteristics.

For example, the currently arriving data is a high-priority data corresponding to slicing, and the UE judges that the data meets the small packet data transmission conditions. At this time, the UE can transmit the small packet data of the slicing service through the CG-SDT resource, and the base station can pass The identifier of the logical channel carrying the data identifies that what is currently being transmitted is the small packet data of the slicing service.

For another example, the currently arriving data is the data of the redcap UE, and the redcap UE judges that the data satisfies the small packet data transmission condition. At this time, the redcap UE can transmit the small packet data through the CG-SDT resource, and the base station can use the CG-SDT resource Identify (it can be understood that the CG-SDT resource is specially configured by the base station for the redcap UE) or identify that the current transmission is the small packet data of the redcap UE through the I-RNTI of the redcap UE.

For another example, if the currently arriving data is a certain high-priority data of the redcap UE, and the redcap UE judges that the data meets the small packet data transmission conditions, the redcap UE can transmit the high-priority slicing small packet through the CG-SDT resource Data, the base station can identify that the current transmission is the small packet data of the slice service of the redcap UE through the CG-SDT resource (it can be understood that the CG-SDT resource is specially configured by the base station for the redcap UE); or through the I- The RNTI and the logical channel identifier carrying the data identify that the current transmission is the small packet data of the slicing service of the redcap UE. Wherein, the small packet data that the UE selects to transmit characteristics or combination of characteristics through the CG-SDT resource may implicitly perform the selection of characteristics or combination of characteristics on behalf of the UE.

This embodiment does not limit the sequence of S1107 and S1108.

S1109: After judging that the CG-SDT condition is not met, the MAC layer continues to judge whether the RA-SDT condition is met. If it is satisfied, execute S1110; otherwise, execute S1102.

S1110: The MAC layer determines that the RA-SDT condition is met, and instructs the RRC layer to meet the condition for initiating the SDT.

S1111: The RRC layer initiates the SDT process, including: restoring the SDT RB, and starting the first timer.

S1112: Before data transmission, the MAC layer selects a feature or a combination of features (ie redcap feature+SDT feature). The MAC layer judges whether there are currently available random access resources with redcap characteristics+SDT characteristics (that is, whether there are random access resources corresponding to redcap characteristics+SDT characteristics in the random access resources configured by the base station through system information). If it exists, execute S1113; otherwise, execute S1114.

Optionally, the UE selects a characteristic or a combination of characteristics when selecting a random access resource, or the UE selects a characteristic or a combination of characteristics before selecting a random access resource.

Optionally, the UE judges whether there is currently an available random access resource for a certain feature or feature combination (for example, redcap UE feature + SDT feature), which may be equivalent to UE selecting a feature or feature combination.

The present application does not limit the sequence of S1111 and S1112.

S1113: When the MAC layer determines that there is a random access resource corresponding to the redcap characteristic+SDT characteristic, the MAC layer executes the RA-SDT process. In this process, the MAC layer can use the random access resources of the redcap feature+SDT feature to initiate random access, and transmit small packet data during the random access process.

S1114: When the MAC layer determines that there is no random access resource corresponding to the redcap characteristic+SDT characteristic, the MAC layer indicates the first information to the RRC layer, and instructs the RRC layer to cancel the SDT process.

For another example, if the UE selects a feature or feature combination based on the implementation or based on the set priority rule, but the feature or feature combination does not include SDT at this time, then the first information needs to be sent at this time.

S1115: The RRC layer cancels the SDT process and executes a normal RRC connection recovery process (that is, a non-SDT RRC connection recovery process). In S1115, the RRC layer may stop the first timer and/or suspend the SDT RB, so as to cancel the SDT process. The RRC may start a second timer (T319) to initiate a normal RRC connection recovery process.

It should be noted that suspending the SDT RBs may be an optional step, because the UE will still restore these RBs after receiving the RRCResume message and entering the RRC Connected state. When the SDT RB is not suspended, the UE can also implement itself to avoid transmitting the data of the SDT RB in msg3/msgA.

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

This application does not limit the sequence of S1115 and S1116.

Based on the embodiments shown in FIG. 6 and FIG. 9 , the present application also provides an embodiment of a communication method. In the embodiment of the present application, it is assumed that the selection of a feature or a combination of features is performed by the MAC layer. The solution provided by this embodiment can be summarized as follows: before the MAC layer indicates to the RRC layer that the conditions for initiating SDT are satisfied, the MAC layer should select a feature or feature combination and judge whether the feature or feature combination implements SDT. It should be noted that this embodiment is a specific example of the embodiment shown in FIG. 6 or FIG. 9 , therefore, the same or corresponding steps may refer to each other.

Based on the above description, a specific data transmission process is now taken as an example. Assuming that the current redcap UE has data transmission requirements, see Figure 12 for the detailed process. The sequence of each step in FIG. 12 is not limited, nor is it limited that each step must be a mandatory step. In addition, the redcap UE feature can be replaced by other features or feature combinations, which is not limited in this application.

S1201-S1209 are the same as S1101-S1109 in the embodiment shown in FIG. 11 , and may refer to each other, and details are not repeated here.

S1210: When the MAC layer determines that the RA-SDT condition is met, the MAC layer selects the first characteristic or characteristic combination. In the embodiment of the present application, it is assumed that the MAC layer selects a characteristic or a combination of characteristics according to at least one characteristic or combination of characteristics configured by the base station and a corresponding random access resource. Therefore, there is a corresponding random access resource for the first characteristic or combination of characteristics.

S1211: The MAC layer judges whether the currently selected feature or feature combination includes the SDT feature, and if not, execute S1202 (it should be noted that, in this case, since the MAC layer has selected the feature or feature combination, the subsequent step MAC layer There is no need to perform the selection step of characteristics or combination of characteristics); if included, execute S1212.

In the current situation, when executing S1202, the MAC layer indicates to the upper layer that the condition for initiating the SDT is not met. At this time, the RRC layer can initiate a non-SDT RRC connection recovery process, and at this time, the MAC layer can perform a random access process according to the first characteristic or combination of characteristics selected by it.

S1212: The MAC layer determines that the currently selected feature or feature combination includes the SDT feature, and indicates to the RRC layer that a condition for initiating the SDT is met. For example, when the selected feature or features are combined as SDT feature + redcap UE feature, the MAC layer indicates to the RRC layer that the condition for initiating SDT is met.

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

S1214: The MAC layer executes the RA-SDT process.

This embodiment does not limit the sequence of S1213 and S1214.

Based on the embodiments shown in FIG. 7 and FIG. 9 , the present application also provides an embodiment of a communication method. In the embodiment of the present application, it is assumed that the selection of a feature or a combination of features is performed by the RRC layer. The solution provided by this embodiment can be summarized as follows: After the MAC layer indicates to the RRC layer that the conditions for initiating SDT are met, the RRC layer first selects a feature or feature combination, and judges whether the feature or feature combination implements SDT. It should be noted that this embodiment is a specific example of the embodiment shown in FIG. 7 or FIG. 9 , therefore, the same or corresponding steps may refer to each other.

Based on the above description, a specific data transmission process is now taken as an example. Assuming that the current redcap UE has data transmission requirements, please refer to Figure 13 for the detailed process. The sequence of each step in FIG. 13 is not limited, nor is it limited that each step must be a mandatory step. In addition, the redcap UE feature can be replaced by other features or feature combinations, which is not limited in this application.

S1301-S1310 are similar to S1101-S1110 in the embodiment shown in FIG. 11 , and reference may be made to each other for similarities.

Since this embodiment is a combination of features or features selected by the RRC layer, the difference from the embodiment shown in Figure 11 is:

In S1302, when the MAC layer determines that the second SDT condition is not satisfied, it indicates to the RRC layer that the condition for initiating the SDT is not satisfied. At this time, the MAC layer cannot directly perform non-SDT random access, but needs to wait for the RRC layer to do further A selection of properties or combinations of properties.

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 the SDT is met. At this time, the MAC layer does not directly initiate the CG-SDT process corresponding to the SDT after judging that the conditions for initiating SDT are met, but only indicates to the RRC layer that the SDT conditions are met, and waits for the RRC layer to make further selections of features or feature combinations. In some embodiments, the UE indicates to the upper layer that the condition for initiating the SDT is met may be that the UE indicates to the upper layer that the condition for initiating the CG-SDT is met.

In S1310, the MAC layer determines that the RA-SDT condition is met, and indicates to the uplink that the condition for initiating the SDT is met. At this time, the MAC layer does not directly initiate the RA-SDT process corresponding to the SDT after judging that the conditions for initiating the SDT are met, but only indicates to the RRC layer that the SDT conditions are met, and waits for the RRC layer to make further selections of characteristics or combination of characteristics. In some embodiments, the UE indicates to the upper layer that the condition for initiating the SDT is met may be that the UE indicates to the upper layer that the condition for initiating the RA-SDT is met.

Optionally, in some embodiments, before S1301, the UE may also be based on "whether the current cell supports a feature or feature combination or at least one feature or feature combination supported by the current cell" indicated in the cell broadcast information (such as a system message) ” or “at least one characteristic or combination of characteristics corresponds to (available) random access resources”, to determine the characteristic or combination of characteristics preferred by the UE. In this way, during the subsequent characteristic selection process, the UE may select the characteristic or characteristic combination with reference to the characteristic or characteristic combination preferred by the UE.

S1311: After the RRC layer receives the indication in S1310, the RRC layer selects a feature or a combination of features. In this embodiment of the present application, the characteristics or characteristics selected by the RRC layer are combined into redcap UE characteristics + SDT characteristics.

In some embodiments, the feature or feature combination selected by the RRC layer in this step can be implemented by the UE itself or can be determined by a predefined priority rule. The specific process can refer to the description about selecting a feature or feature combination in the above embodiments , which will not be repeated here.

S1312: The RRC layer judges whether there are currently available random access resources with redcap UE characteristics + SDT characteristics (that is, whether there are random access resources corresponding to redcap characteristics + SDT characteristics in the random access resources configured by the base station through system information). If not, execute S1303, and if yes, execute S1313.

For another example, after the RRC layer receives the condition indication for initiating SDT sent by the MAC, the RRC layer selects a feature or feature combination, and judges whether the currently selected feature or feature combination includes SDT.

The UE judges whether there is currently a random access resource available for a certain feature or feature combination (for example, redcap UE feature + SDT feature), which can be equivalent to UE selecting a feature or feature combination. In some embodiments, the premise of this step is that the RRC layer receives an indication that the MAC layer meets the RA-SDT condition.

In the current situation, when there is no random access resource corresponding to the redcap UE characteristic+SDT characteristic, in S1303, the RRC layer may also select another characteristic or a combination of characteristics (such as the redcap UE characteristic), and use this characteristic Or the characteristic combination or the random access resource corresponding to the characteristic or characteristic combination is indicated to the MAC layer. In this way, the MAC layer can perform non-SDT random access based on the characteristic or the characteristic combined with the corresponding random access resource.

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

For example, the SDT process in this step is an RRC connection recovery process corresponding to the SDT feature or feature combination (redcap feature+SDT feature).

S1314: The MAC layer executes the RA-SDT process. For example, the MAC layer performs a random access procedure including SDT. For example, performing the random access process including the SDT at the MAC layer may include that the MAC layer performs random access based on random access related parameters selected by the RRC layer.

Based on the same technical idea, the present application also provides a communication device, which is applied to a UE in the mobile communication system as shown in FIG. 1 . The communication device is used to implement the communication methods provided in the above embodiments and examples. Referring to FIG. 14 , a 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.

The communication unit 1401 is configured to receive and send signals. Optionally, the communication unit 1401 may include a transceiver.

In an implementation manner, the communication device is used to realize the embodiment shown in any one of FIG. 6 , 7 , 9 , 12 , or 13 . The processing unit 1402 is used for:

When the UE is in the RRC inactive state, after determining that the condition for initiating the SDT is met, determine the first feature or feature combination;

When the first characteristic or combination of characteristics includes an SDT characteristic, and random access resources corresponding to the first characteristic or combination of characteristics exist in random access resources configured by the base station, an SDT process is performed.

Optionally, the processing unit 1402, when determining the first characteristic or combination of characteristics, is specifically configured to:

Select the first feature or feature combination from at least one feature or feature combination supported by the UE and supported by the base station according to at least one or a combination of the following:

Setting selection rules, characteristics configured by the base station or characteristics combined with corresponding random access resources, transmission requirements of the UE, services of the UE, and coverage status of the UE.

Optionally, the processing unit 1402, when executing the SDT process, is specifically configured to:

Restoring the SDT radio bearer RB and starting a first timer; wherein, the first timer is used to detect whether the SDT process is successful, and the SDT RB is an RB for performing SDT;

During the timing of the first timer, use the first feature or feature in conjunction with the corresponding random access resource to initiate random access, and send target data during the random access process; wherein the target data is carried in In the SDT RB.

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 used to detect whether the SDT process is successful, and the SDT RB is used for RB that executes SDT.

The MAC layer processing unit is configured to: during the timing process of the first timer, use the first feature or the feature in conjunction with the corresponding random access resource to initiate random access, and send a target during the random access process Data; wherein, the target data is carried in the SDT RB.

Optionally, the processing unit 1402, after determining that the condition for initiating SDT is satisfied, determines the first characteristic or combination of characteristics; when: the MAC layer processing unit is configured to determine the first characteristic or characteristic after determining that the condition for initiating SDT is satisfied Combine;

The MAC layer processing unit is further configured to: before executing the SDT process, send a first message to the RRC layer processing unit, where the first message is used to indicate that a condition for initiating SDT is met.

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

The RRC layer processing unit is configured to: select the first feature or feature combination.

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

Optionally, the processing unit 1402 is further configured to: when the first characteristic or combination of characteristics does not include the SDT characteristic, and/or, the first characteristic does not exist in the random access resources configured by the base station or When the characteristics are combined with the corresponding random access resources, an RRC connection recovery process is performed, so that the UE enters a connected state. Optionally, the RRC layer processing unit executes an RRC connection recovery process.

Optionally, the processing unit 1402 is further configured to: when the first characteristic or combination of characteristics does not include the SDT characteristic, and/or, the first characteristic does not exist in the random access resources configured by the base station or When the characteristics are combined with the corresponding random access resources, use the first random access resources configured by the base station to initiate random access; wherein, when the random access resources configured by the base station do not include the first characteristics or the combination of characteristics corresponding random access resource, the first random access resource is the same as the second characteristic configured by the base station or the random access resource corresponding to the characteristic combined with the characteristic; when the random access resource configured by the base station includes the When the first characteristic or the characteristic is combined with the corresponding random access resource, the first random access resource is the first characteristic or the characteristic is combined with the corresponding random access resource.

Optionally, the MAC layer processing unit performs a process of initiating random access.

Optionally, any feature or combination of features includes at least one of the following:

SDT feature, network slicing feature, low or reduced capability UE redcap UE feature, and coverage enhancement CE UE feature.

In another implementation manner, the communication device is used to implement the embodiment shown in any one of FIG. 8 , FIG. 10 or FIG. 11 . The processing unit 1402 is configured to:

When the UE is in the RRC inactive state, after determining that the condition for initiating the SDT is satisfied, start the SDT process, and determine the first feature or feature combination;

When the first characteristic or characteristic combination does not include the SDT characteristic, and/or, when the random access resources corresponding to the first characteristic or characteristic combination do not exist in the random access resources configured by the base station, cancel the SDT process.

Optionally, the processing unit 1402, when determining the first characteristic or combination of characteristics, is specifically configured to:

Selecting the first feature or feature combination from at least one feature or feature combination supported by the UE and supported by the base station according to at least one or a combination of the following:

Setting selection rules, characteristics configured by the base station or characteristics combined with corresponding random access resources, transmission requirements of the UE, services of the UE, and coverage status of the UE.

Optionally, when the processing unit 1402 cancels the SDT process:

The RRC layer processing unit cancels the SDT process after receiving the first message sent from the MAC layer processing unit; wherein the first message is used to notify the RRC layer to cancel the SDT process.

Optionally, when the processing unit 1402 starts the SDT process:

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 an RB used to perform SDT;

When the first characteristic or combination of characteristics includes the SDT characteristic, and the random access resources corresponding to the first characteristic or combination of characteristics exist in the random access resources configured by the base station, during the timing of the first timer During the process, the MAC layer processing unit initiates random access by using the first feature or the feature in combination with the corresponding random access resource, and sends target data during the random access process; wherein the target data is carried in the SDT RB;

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

Stopping the first timer, and/or suspending the SDT RB.

Optionally, the processing unit 1402 is further configured to: when the first characteristic or combination of characteristics does not include the SDT characteristic, and/or, the first characteristic does not exist in the random access resources configured by the base station or When the characteristics are combined with the corresponding random access resources, the RRC connection recovery process is performed. Optionally, the RRC layer processing unit executes an RRC connection recovery process.

Optionally, the processing unit 1402 is further configured to: when the first characteristic or combination of characteristics does not include the SDT characteristic, and/or, the first characteristic does not exist in the random access resources configured by the base station or When the characteristics are combined with the corresponding random access resources, use the first random access resources configured by the base station to initiate random access; wherein, when the random access resources configured by the base station do not include the first characteristics or the combination of characteristics corresponding random access resource, the first random access resource is the same as the second characteristic configured by the base station or the random access resource corresponding to the characteristic combined with the characteristic; when the random access resource configured by the base station includes the When the first characteristic or the characteristic is combined with the corresponding random access resource, the first random access resource is the first characteristic or the characteristic is combined with the corresponding random access resource. Optionally, the MAC layer processing unit executes a random access process.

Optionally, any feature or combination of features includes at least one of the following:

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

Based on the above embodiments, this embodiment of the present application also provides a UE, which can be applied to the mobile communication system shown in Figure 1, and can implement the methods in the above embodiments, and has the communication communication provided by the above embodiments The functionality of the device 1400 . Referring to FIG. 15 , the UE 1500 includes: a transceiver 1501 and at least one processor 1502. Optionally, the communication device 1500 further includes a memory 1503 . Wherein, the transceiver 1501, the processor 1502, and the memory 1503 are connected to each other.

Optionally, the transceiver 1501 , the at least one processor 1502 and the memory 1503 are connected to each other through a bus 1504 . The bus 1504 may be a peripheral component interconnect standard (peripheral component interconnect, PCI) bus or an extended industry standard architecture (extended industry standard architecture, EISA) bus or the like. The bus can be divided into address bus, data bus, control bus and so on. For ease of representation, only one thick line is used in FIG. 15 , but it does not mean that there is only one bus or one type of bus.

The transceiver 1501 is used to receive and send signals to realize communication with other devices in the mobile communication system. Optionally, the transceiver 1501 may be implemented by using a radio frequency device and an antenna.

The at least one processor 1502 includes an RRC layer processing unit and a MAC layer processing unit. Wherein, the RRC layer processing unit is used to execute the steps of the RRC layer to realize the functions of the RRC layer. The MAC layer processing unit is used to execute the steps of the MAC layer to realize the functions of the MAC layer.

For the functions of the processor 1502 and the specific functions of the RRC layer processing unit and the MAC layer processing unit, reference may be made to the descriptions in the above embodiments, and details are not repeated here.

Wherein, the processor 1502 may be a central processing unit (central processing unit, CPU), a network processor (network processor, NP) or a combination of CPU and NP, etc. The processor 1502 may further include a hardware chip. The aforementioned hardware chip may be an application-specific integrated circuit (application-specific integrated circuit, ASIC), a programmable logic device (programmable logic device, PLD) or a combination thereof. The aforementioned PLD may be a complex programmable logic device (complex programmable logic device, CPLD), a field-programmable gate array (field-programmable gate array, FPGA), a general array logic (generic array logic, GAL) or any combination thereof. When the processor 1502 realizes the above functions, it may be realized by hardware, and of course, it may also be realized by executing corresponding software by hardware.

The memory 1503 is used to store program instructions and the like. Specifically, the program instructions may include program codes including computer operation instructions. The memory 1503 may include a random access memory (random access memory, RAM), and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory. The processor 1502 executes the program instructions stored in the memory 1503 to implement the above functions, thereby implementing the methods provided in the above embodiments.

Based on the above embodiments, an embodiment of the present application further provides a computer program that, when the computer program is run on a computer, causes the computer to execute the method provided in the above embodiments.

Based on the above embodiments, the embodiments of the present application also provide a computer-readable storage medium, in which a computer program is stored, and when the computer program is executed by a computer, the computer executes the method provided in the above embodiments .

Wherein, the storage medium may be any available medium that can be accessed by a computer. By way of example but not limitation: computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage media or other magnetic storage devices, or may be used to carry or store information in the form of instructions or data structures desired program code and any other medium that can be accessed by a computer.

Based on the above embodiments, an embodiment of the present application further provides a chip, the chip is used to read a computer program stored in a memory, and implement the method provided in the above embodiments.

Based on the above embodiments, an embodiment of the present application provides a chip system, where the chip system includes a processor, configured to support a computer device to implement the functions involved in the communication device in the above embodiments. In a possible design, the chip system further includes a memory, and the memory is used to store necessary programs and data of the computer device. The system-on-a-chip may consist of chips, or may include chips and other discrete devices.

To sum up, the embodiments of the present application provide a communication method and device. In this method, after the UE meets the conditions for initiating SDT, the selected first feature or feature combination includes the SDT feature, and the base station configures The SDT process is executed when the first characteristic exists in the random access resource or the characteristic is combined with the corresponding random access resource. Compared with the traditional solution, the UE initiates the SDT process when it meets the conditions for initiating SDT. In the method provided by the embodiment of this application, the UE initiates the SDT process only when the selected feature or the combination of features can realize the SDT, so as to avoid the situation that the SDT process cannot be realized. In the case of wrongly starting the first timer to initiate the phenomenon of the SDT process, thereby avoiding the adverse impact on power consumption and data transmission delay caused by wrongly starting the first timer or causing waste of air interface resources and/or signaling question. Therefore, the method can ensure reduction of UE power consumption and data transmission delay, or reduce waste of air interface resources and/or signaling.

Those skilled in the art should understand that the embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may 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.) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to the present application. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

Apparently, those skilled in the art can make various changes and modifications to the present application without departing from the scope of the present application. In this way, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims (19)

A communication method, applied to a user equipment UE, characterized in that it includes: When the UE is in the radio resource control RRC inactive state, after determining that the condition for initiating small packet transmission SDT is satisfied, determine the first characteristic or characteristic combination; When the first characteristic or combination of characteristics includes an SDT characteristic, and random access resources corresponding to the first characteristic or combination of characteristics exist in random access resources configured by the base station, an SDT process is performed. The method of claim 1, wherein determining the first characteristic or combination of characteristics comprises: Selecting the first feature or feature combination from at least one feature or feature combination supported by the UE and supported by the base station according to at least one or a combination of the following: Setting selection rules, characteristics configured by the base station or characteristics combined with corresponding random access resources, transmission requirements of the UE, services of the UE, and coverage status of the UE. The method according to claim 1 or 2, wherein performing the SDT process comprises: Restoring the SDT radio bearer RB and starting a first timer; wherein, the first timer is used to detect whether the SDT process is successful, and the SDT RB is an RB for performing SDT; During the timing of the first timer, use the first feature or feature in conjunction with the corresponding random access resource to initiate random access, and send target data during the random access process; wherein the target data is carried in In the SDT RB. The method according to any one of claims 1-3, characterized in that, After it is determined that the conditions for initiating the SDT are met, determine the first feature or combination of features, including: After the medium access control MAC layer of the UE determines that the condition for initiating SDT is met, the MAC layer determines the first characteristic or characteristic combination; Before performing the SDT process, the method also includes: The MAC layer sends a first message to the RRC layer of the UE, where the first message is used to indicate that a condition for initiating an SDT is met. The method according to any one of claims 1-3, wherein after determining that the condition for initiating the SDT is satisfied, determining the first characteristic or combination of characteristics includes: After the MAC layer of the UE determines that the condition for initiating SDT is met, the MAC layer sends a second message to the RRC layer, where the second message is used to indicate that the condition for initiating SDT is met; The RRC layer selects the first characteristic or characteristic combination. The method of claim 5, further comprising: The MAC layer receives a third message from the RRC layer, where the third message is used to instruct the MAC layer to initiate SDT random access. The method according to any one of claims 1-6, further comprising: When the first characteristic or characteristic combination does not include the SDT characteristic, and/or when the random access resources corresponding to the first characteristic or characteristic combination do not exist in the random access resources configured by the base station, perform RRC connection recovery process, so that the UE enters the connected state. The method according to claim 7, wherein when the first characteristic or combination of characteristics does not include the SDT characteristic, and/or, the first characteristic or characteristic does not exist in the random access resource configured by the base station When combined with the corresponding random access resources, the method further includes: Initiate 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 exist the first characteristic or the characteristic is combined with a corresponding random access resource, the The first random access resource is the same as the random access resource corresponding to the second characteristic or characteristic combination configured by the base station; when the random access resource corresponding to the first characteristic or characteristic combination exists in the random access resource configured by the base station When inputting resources, the first random access resource is a random access resource corresponding to the first characteristic or characteristic combination. The method according to any one of claims 1-8, wherein the first characteristic or combination of characteristics comprises at least one of the following: SDT features, network slicing slicing features, low-capability or reduced-capability UE redcap UE features, and coverage enhancement CE UE features. A communication method, applied to a user equipment UE, characterized in that it includes: When the UE is in the radio resource control RRC inactive state, after determining that the condition for initiating small packet transmission SDT is met, start the SDT process, and determine the first characteristic or characteristic combination; When the first characteristic or characteristic combination does not include the SDT characteristic, and/or, when the random access resources corresponding to the first characteristic or characteristic combination do not exist in the random access resources configured by the base station, cancel the SDT process. The method of claim 10, wherein determining the first characteristic or combination of characteristics comprises: Selecting the first feature or feature combination from at least one feature or feature combination supported by the UE and supported by the base station according to at least one or a combination of the following: Setting selection rules, characteristics configured by the base station or characteristics combined with corresponding random access resources, transmission requirements of the UE, services of the UE, and coverage status of the UE. The method according to claim 10 or 11, wherein canceling the SDT process comprises: The RRC layer of the UE cancels the SDT process after receiving the first message sent from the MAC layer; wherein, the first message is used to notify the RRC layer to cancel the SDT process. The method according to claim 12, wherein starting the SDT process comprises: 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; The method also includes: When the first characteristic or combination of characteristics includes the SDT characteristic, and the random access resources corresponding to the first characteristic or combination of characteristics exist in the random access resources configured by the base station, during the timing of the first timer During the process, the MAC layer initiates random access using the first characteristic or characteristic in combination with the corresponding random access resource, and sends target data during the random access process; wherein the target data is carried on the SDT RB middle; The RRC layer cancels the SDT process, including: The RRC layer stops the first timer, and/or, the RRC layer suspends the SDT RB. The method according to any one of claims 10-13, wherein 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 include the When the first characteristic or the characteristic is combined with the corresponding random access resource, the method further includes: Execute the RRC connection recovery procedure. The method according to any one of claim 14, wherein, when the first characteristic or combination of characteristics does not include the SDT characteristic, and/or, the random access resources configured by the base station do not include the first When the characteristic or the characteristic is combined with the corresponding random access resource, the method further includes: Initiate random access using the first random access resource configured by the base station; wherein, when the first characteristic does not exist in the random access resource configured by the base station or the characteristic is combined with a corresponding random access resource, the The first random access resource is the same as the random access resource corresponding to the second characteristic or characteristic combination configured by the base station; when the random access resource corresponding to the first characteristic or characteristic combination exists in the random access resource configured by the base station When inputting resources, the first random access resource is a random access resource corresponding to the first characteristic or characteristic combination. The method according to any one of claims 10-15, wherein the first characteristic or combination of characteristics comprises at least one of the following: SDT features, network slicing slicing features, low-capability or reduced-capability UE redcap UE features, and coverage enhancement CE UE features. A user equipment UE, characterized in that it includes: Transceivers for receiving and sending signals; memory for storing program instructions and data; A processor, configured to read program instructions and data in the memory, and implement the method according to any one of claims 1-16 through the transceiver. A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and when the computer program is run on a computer, the computer is made to execute the computer program described in any one of claims 1-16. described method. A chip, characterized in that the chip is coupled with a memory, and the chip reads a computer program stored in the memory to execute the method according to any one of claims 1-16.

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