Controlling non-SDT data transmission

Abstract

Embodiments of the present disclosure relate to devices, methods, apparatus, and computer-readable storage media for controlling DCCH-based non-small data transmission (SDT) data arrival. In some example embodiments, a terminal device transmits an indication of availability of non-small data transmission (SDT) data to a network device during an SDT procedure. The terminal device monitors a response to the indication and performs an action in response to a lack of a response to the indication of non-SDT data. The action includes entering an idle or inactive state and / or initiating a connection setup or resumption request to the network device.

Description

[Technical Field]

[0001] FIELD Embodiments of the present disclosure relate generally to the field of telecommunications, and more particularly to devices, methods, apparatus, and computer-readable storage media for controlling non-small data transmissions. [Background technology]

[0002] With the development of communication technology, small data transmission (SDT) was introduced to avoid the signaling overhead and delay caused by transitioning from inactive mode to connected mode. In the SDT procedure, a terminal device in inactive mode can transmit small data packets to a network device on an uplink channel without transitioning to connected mode. In some circumstances, data may become available on a radio bearer that is not configured for SDT during the SDT procedure. Such data may be referred to as non-SDT data. Traditionally, resources configured for SDT do not allow non-SDT data to be transmitted to a network device. Summary of the Invention

[0003] Generally, exemplary embodiments of the present disclosure provide devices, methods, apparatus, and computer-readable storage media for controlling non-SDT data transmissions.

[0004] In a first aspect, a terminal device is provided. The terminal device comprises at least one processor and at least one memory containing computer program code. The at least one memory and computer program code are configured, using the at least one processor, to cause the terminal device to transmit an indication of availability of non-small data transmission (SDT) data to a network device during an SDT procedure. The at least one memory and computer program code further cause the terminal device to monitor a response to the indication and, in response to a lack of a response to the indication, perform an action. The action may include entering an idle or inactive state and / or sending a connection setup or resumption request to the network device.

[0005] In a second aspect, a method is provided for implementation in a terminal device, in which the terminal device transmits an indication of availability of non-small data transmission (SDT) data to a network device during an SDT procedure. The terminal device monitors a response to the indication and performs an action in response to a lack of a response to the indication. The action may include entering an idle or inactive state and / or initiating a connection setup or resumption request to the network device.

[0006] In a third aspect, there is provided an apparatus comprising means for carrying out the method according to the second aspect.

[0007] In a fourth aspect, there is provided a computer-readable storage medium having stored thereon instructions that, when executed by at least one processor, cause the at least one processor to perform a method according to the second aspect.

[0008] Other features of the present disclosure will become readily apparent from the following description.

[0009] The above and other objects, features, and advantages of the present disclosure will become more apparent through a more detailed description of some exemplary embodiments of the present disclosure in the accompanying drawings. [Brief explanation of the drawings]

[0010] [Figure 1] 1 illustrates an exemplary environment in which exemplary embodiments of the present disclosure may be implemented. [Figure 2] 1 illustrates a process for controlling non-SDT data transmission according to some embodiments of the present disclosure. [Figure 3] 1 illustrates a flowchart of an exemplary process implemented at a terminal device, according to some embodiments of the present disclosure. [Figure 4] FIG. 1 is a simplified block diagram of a device suitable for implementing embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Throughout the drawings, the same or similar reference numbers represent the same or similar elements.

[0012] The principles of the present disclosure will now be described with reference to some exemplary embodiments. Of course, these embodiments are provided for illustrative purposes only, to assist those skilled in the art in understanding and practicing the present disclosure, but are not intended to imply any limitations on the scope of the present disclosure. The disclosure described herein can be implemented in various ways other than those described below.

[0013] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0014] As used herein, the term "network device" refers to a device that can provide or host a cell or coverage area over which additional devices, such as terminal devices, can communicate. Examples of network devices include, but are not limited to, a Node B (Node B or NB), an Evolved Node B (eNode B or eNB), a next-generation eNB (ng-eNB), a ng-eNB central unit (ng-eNB-CU), a ng-eNB distributed unit (ng-eNB-DU), a next-generation Node B (gNB), a gNB central unit (gNB-CU), a gNB distributed unit (gNB-DU), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), an integrated access and backhaul (IAB) node, a low-power node such as a femto node or a pico node, etc.

[0015] As used herein, the term "terminal device" refers to any device with wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to, user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, tablets, wearable devices, Internet of Things (IoT) devices, Internet of Everything (IoE) devices, machine-type communication (MTC) devices, devices on vehicles for V2X communications (where X stands for pedestrian, vehicle, or infrastructure / network), devices for integrated access and backhaul (IAB), or image capture devices such as digital cameras, gaming devices, music storage and playback devices, or Internet appliances that enable wireless or wired Internet access and browsing, etc. As used herein, the term "terminal device" can be used interchangeably with UE.

[0016] As used herein, the term "circuit" may refer to a hardware circuit and / or a combination of a hardware circuit and software. For example, a circuit may be a combination of analog and / or digital hardware circuitry and software / firmware. As a further example, a circuit may be any portion of a software-based hardware processor, including digital signal processor(s), software, and memory(s), that cooperate to cause an apparatus, such as a terminal device or a network device, to perform various functions. As a still further example, a circuit may be a hardware circuit and / or a processor, such as a microprocessor or portion of a microprocessor, that requires software / firmware for operation, but the software may not be present if not necessary for operation. As used herein, the term circuit also encompasses implementations of just a hardware circuit, or processor(s), or portion of a hardware circuit or processor(s), along with any accompanying software and / or firmware.

[0017] As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The term "comprising" and variations thereof should be interpreted as open terms meaning "including, but not limited to." The term "based on" should be interpreted as "based at least in part on." The terms "one embodiment" and "embodiment" should be interpreted as "at least one embodiment." The term "another embodiment" should be interpreted as "at least one other embodiment." Terms such as "first," "second," etc. may refer to different objects or the same object.

[0018] As described above, non-SDT data may become available to be transmitted from the terminal device to the network device while an SDT procedure is in progress. Two possible approaches for the terminal device to indicate the availability of non-SDT data to the network device are based on a common control channel (CCCH) indication and a dedicated control channel (DCCH) indication. In the CCCH-based approach, when non-SDT data arrives in a buffer of a radio bearer that is not configured for SDT, the terminal device terminates the SDT procedure and triggers a radio resource control (RRC) resumption or establishment procedure to set up an RRC connection to the network device. In the DCCH-based approach, when non-SDT data arrives in a buffer of a radio bearer that is not configured for SDT, the SDT procedure is maintained, and the terminal device can send an indication of the availability of non-SDT data to the network device (e.g., using an RRC message). When the indication of non-SDT data is received, the network device can instruct the terminal device to transition from an inactive mode to a connected mode to transmit the non-SDT data. The CCCH-based approach is so named because the indication is sent on the CCCH channel (on Signaling Radio Bearer 0 (SRB0)) by RRCResumeRequest. The DCCH-based approach is so named because the indication is sent on the DCCH channel (on SRB1, SRB2, or SRB3) by a new or existing RRC message (such as UEAssistanceInformation).

[0019] However, in some situations, for example, due to poor radio wave conditions, the network device may not be able to receive or decode the indication for non-SDT data, or the terminal device may not be able to receive or decode the instruction sent by the network device in response to the indication. Furthermore, the network device may fail to send the instruction for other reasons, such as resource congestion. Thus, without an instruction from the network device, the terminal device may not enter connected mode in time. For high-priority non-SDT data, this may cause undesirable delays.

[0020] Furthermore, an SDT failure timer is defined to monitor the failure of the SDT procedure. However, since the time required for the SDT procedure cannot be predicted in advance, the SDT failure timer is long (e.g., 10 seconds). Furthermore, since SDT data is generally not high priority, long delays in determining failure are not an issue, unlike the arrival of high-priority data or emergency calls. Therefore, undesirable delays may occur even with non-SDT data.

[0021] An example embodiment of the present disclosure provides a scheme for controlling non-SDT data transmission. In this scheme, when non-SDT data to transmit to a network device becomes available during an SDT procedure, the terminal device transmits an indication of the non-SDT data to the network device. The terminal device then monitors a response from the network device to the indication. If the terminal device detects a response, such as an RRCResume message, the terminal device can transition from an inactive mode to a connected mode and transmit the non-SDT data to the network device. If the terminal device determines that there is no response from the network device, the terminal device terminates the SDT procedure, enters an inactive or idle mode, and / or triggers the transmission of a connection setup or resumption request to the network device. For example, the terminal device can transmit an RRCSetupRequest or RRCResumeRequest to the network device to initiate or resume a radio resource control (RRC) connection with the network device to transmit the non-SDT data.

[0022] In this way, the transmission of non-SDT data can be timely and transmission delays can be reduced.

[0023] FIG. 1 illustrates an exemplary environment 100 in which exemplary embodiments of the present disclosure may be practiced.

[0024] The environment 100 may be part of a communication network and includes a terminal device 110 and a network device 120 .

[0025] Of course, the number of terminal devices and network devices shown in environment 100 is for illustrative purposes only and does not imply any limitation on the scope of the present disclosure. In some embodiments, environment 100 may include additional terminal devices and / or additional network devices.

[0026] Terminal device 110 may communicate with network device 120 or further terminal devices (not shown) directly or via network device 120 . Communications in environment 100 may conform to any suitable communications standard or protocol, whether existing or developed in the future, such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Fifth Generation (5G) New Radio (NR), Wireless Fidelity (Wi-Fi), and Worldwide Interoperability for Microwave Access (WiMAX) standards, and employ any suitable communications technology, such as multiple-input multiple-output (MIMO), orthogonal frequency division multiplexing (OFDM), time division multiplexing (TDM), frequency division multiplexing (FDM), code division multiplexing (CDM), Bluetooth, ZigBee, and machine type communications (MTC), enhanced mobile broadband (eMBB), massive machine type communications (mMTC), ultra-reliable low latency communications (URLLC), carrier aggregation (CA), dual connection (DC), and unlicensed new radio (NR-U) technologies.

[0027] The terminal device 110 can access a cell served by the network device 120 and can transmit small data packets to the network device 120 during an SDT procedure when the terminal device 110 is in an inactive mode. In the SDT procedure, data available on a radio bearer configured for SDT can be transmitted to the network device 120 in small data packets. However, data available on a radio bearer not configured for SDT cannot be transmitted in the SDT procedure.

[0028] 2 illustrates a process 200 for controlling non-SDT data transmission according to some embodiments of the present disclosure. For illustrative purposes, flowchart 200 will be described with reference to FIG.

[0029] In process 200, during an SDT procedure between terminal device 110 and network device 120, after non-SDT data becomes available to be transmitted to network device 120, terminal device 110 transmits an indication of the availability of the non-SDT data to network device 120 (210). The non-SDT data includes available data on radio bearers that are not configured (or not configured) for SDT. Terminal device 110 may transmit the indication of the non-SDT data to network device 120 in any manner.

[0030] In some embodiments, the terminal device 110 may transmit the indication of non-SDT data availability in an RRC message. In some embodiments, the terminal device 110 may transmit the indication in medium access control (MAC) signaling or physical layer (PHY) signaling. In some embodiments, the terminal device 110 may transmit the indication in an existing message, for example, the terminal device 110 may transmit the indication of non-SDT data in user equipment (UE) assistance information. In some embodiments, the terminal device 110 may reuse other existing signaling or messages to transmit the indication. In some embodiments, the terminal device 110 may transmit the indication of non-SDT data in a separate uplink RRC message that may be defined for that purpose.

[0031] Terminal device 110 then monitors 220 for a response to the indication. For example, network device 120 may send a response to the indication to terminal device 110. In some embodiments, the response may include at least one of an RRCResume message, an RRCSetup message, an RRCRelease message, an RRCRelease with suspendConfig message, or an RRCReject message. In some embodiments, the response may include any other message, signaling, or system information sent by network device 120 for the indication of non-SDT data. Based on the response received from network device 120, terminal device 110 may perform corresponding action to transmit the non-SDT data to the network.

[0032] In some circumstances, such as poor signal quality, the terminal device 110 may not receive a response to the indication of non-SDT data from the network device 120. In this case, the terminal device 110 may determine that there is no response to the indication of non-SDT data.

[0033] In some embodiments, the terminal device may employ a timer to monitor responses to determine if there is a lack of response to the indication of non-SDT data. When the monitoring timer expires, the terminal device 110 may determine that there is a lack of response to the indication of non-SDT data.

[0034] In some embodiments, a timer may be defined or configured that is dedicated to sending indications of non-SDT data.

[0035] Additionally or alternatively, an existing timer may be reused as the monitoring timer. For example, the T319 timer may be reused as the monitoring timer. In some embodiments, as described above, the terminal device 110 may send an indication of non-SDT data in the UE assistance information, and therefore the UE assistance information prohibit timer may be reused as the monitoring timer. In this case, when the UE assistance information prohibit timer expires, the terminal device 110 may determine that there is no response to the indication of non-SDT data. In some embodiments, any other existing timer may be reused as the monitoring timer.

[0036] The monitoring timer may be started upon transmission of the non-SDT data indication. Alternatively, or additionally, the monitoring timer may be stopped upon cell reselection initiated by the terminal device 110 or upon receipt of a response to the non-SDT data indication. In some embodiments, the response to the non-SDT data indication may include at least one of an RRCResume message, an RRCSetup message, an RRCRelease message, an RRCRelease with suspendConfig message, or an RRCReject message. In some embodiments, the response may include any other message, signaling, or system information sent by the network device 120 for the non-SDT data indication. In some embodiments, the response may include an RRCReject message indicating an action to the terminal device 110. For example, the RRCReject message may indicate the terminal device 110 to transition to an idle mode or an inactive mode and / or may indicate the network device 120 to initiate a connection setup or resumption request. In some embodiments, if the terminal device 110 receives an RRCReject message, the terminal device 110 may maintain the SDT procedure. In some embodiments, if the terminal device 110 receives an RRCReject message, the terminal device 110 may terminate the SDT procedure.

[0037] In some embodiments, the SDT failure timer may also be reused as a monitoring timer. In some embodiments, the terminal device may determine that there is no response to the non-SDT data indication when the SDT failure timer expires. In some embodiments, a timer dedicated to transmitting an indication of non-SDT data may be defined or configured, and the terminal device 110 may determine that there is no response to the non-SDT data indication based on both the timer dedicated to transmitting an indication of non-SDT data and the SDT failure timer. For example, when either of these two timers expires, the terminal device 110 may determine that there is no response to the non-SDT data indication. In some embodiments, the SDT failure timer may be stopped when the timer dedicated to transmitting an indication of non-SDT data is started or when an indication of non-SDT data is transmitted. For example, if an indication of non-SDT data is sent very close to the expiration of the SDT failure timer (e.g., only a few milliseconds until the expiration of the SDT failure timer), stopping the SDT failure timer when the indication of non-SDT data is sent or when a timer dedicated to sending the indication of non-SDT data is started allows sufficient time for network device 120 to respond to the indication. Thus, stopping the SDT failure timer ensures that the network has time to respond to the non-SDT data if the timer would otherwise expire soon.

[0038] In addition to or instead of the monitoring timer, the terminal device 110 may employ other methods for determining lack of response to the non-SDT data indication. In some embodiments, the terminal device 110 may employ a counter for counting the number of transmissions or retransmissions of the non-SDT data indication to determine lack of response to the non-SDT data indication. In this case, a "max_amount_of_times" for the number of indication transmissions or retransmissions may be predetermined. If the number of indication transmissions or retransmissions reaches "max_amount_of_times," the terminal device 110 may determine lack of response to the non-SDT data indication. In some embodiments, the transmission or retransmission of the indication is triggered based on a timer or a non-access stratum (NAS). For example, the terminal device 110 may transmit the non-SDT data indication periodically based on a timer or may transmit the indication based on an NAS indication. In some embodiments, the number of indication transmissions or retransmissions may be performed and maintained by the radio link control (RLC) layer. For example, if a maximum number of RLC retransmissions is reached, terminal device 110 may determine that there is no response to the indication of non-SDT data.

[0039] In some embodiments, different expiration times for the monitoring timer and counter "max_amount_of_times" may be predetermined based on different services, signaling or data radio bearers (SRB or DRB), trigger types, establishment causes, or may be dynamically changed on demand.

[0040] If the terminal device 110 determines that there is no response to the non-SDT data indication, the terminal device 110 performs (230) actions including entering an idle or inactive state and / or sending (240) a connection setup or resumption request to the network device 120.

[0041] In some embodiments, terminal device 110 may terminate the SDT procedure and enter an idle or inactive state. In some embodiments, terminal device 110 may initiate a connection setup or resumption request to network device 120 by sending an RRCSetupRequest or RRCResumeRequest.

[0042] In this way, the transmission of non-SDT data can be timely and transmission delays can be reduced.

[0043] FIG. 3 illustrates a flowchart of an example method 300 implemented in a terminal device, according to some embodiments of the present disclosure.

[0044] Method 300 may be implemented in terminal device 110 shown in Figure 1. For purposes of explanation, method 300 will be described with reference to Figure 1. Of course, method 300 may include additional operations not shown and / or omit some of the operations shown, and the scope of the disclosure is not limited in this respect.

[0045] At 310, the terminal device 110 transmits an indication of non-small data transmission (SDT) data availability to the network device 120 during an SDT procedure.

[0046] At 320, the terminal device 110 monitors a response to the indication.

[0047] At 330, terminal device 110 performs an action in response to the lack of a response to the indication, including entering an idle or inactive state and / or initiating a connection setup or resumption request to network device 120.

[0048] In some embodiments, non-SDT data includes data available on radio bearers that are not configured for SDT.

[0049] In some embodiments, monitoring the response to the indication includes monitoring the response to the indication until expiration of a monitoring timer or until a predetermined number of transmissions of the indication of non-SDT data.

[0050] In some embodiments, the monitoring timers include at least one of an SDT failure timer, a timer dedicated to sending indications of non-SDT data, a T319 timer, and a user equipment (UE) assistance information prohibit timer.

[0051] In some embodiments, the method 300 further includes retransmitting the indication upon expiration of the timer or retransmitting the indication based on an indication from a non-access stratum (NAS).

[0052] In some embodiments, the monitoring timer is started upon transmission of the indication and / or the monitoring timer is stopped upon at least one of cell reselection initiated by the terminal device or upon receipt of a response to the indication.

[0053] In some embodiments, the response includes at least one of an RRCResume message, an RRCSetup message, an RRCRelease message, an RRCRelease with suspendConfig message, or an RRCReject message.

[0054] In some embodiments, the indication of non-SDT data is sent in at least one of an RRC message, MAC signaling, PHY signaling, and UE assistance information.

[0055] 4 is a simplified block diagram of a device 400 suitable for practicing exemplary embodiments of the present disclosure. The device 400 may be implemented in the terminal device 110 shown in FIG.

[0056] As shown, device 400 includes a processor 410, a memory 420 coupled to the processor 410, a communication module 430 coupled to the processor 410, and a communication interface (not shown) coupled to the communication module 430. The memory 420 stores at least a program 440. The communication module 430 is for two-way communication, for example, via multiple antennas or cables. The communication interface may represent any interface required for communication.

[0057] The program 440 is assumed to include program instructions that, when executed by an associated processor 410, enable the device 400 to operate in accordance with exemplary embodiments of the present disclosure as described herein with reference to Figures 1-2. The exemplary embodiments of the present disclosure may be implemented by computer software executable by the processor 410 of the device 400, by hardware, or by a combination of software and hardware. The processor 410 may be configured to implement various exemplary embodiments of the present disclosure.

[0058] The memory 420 may be of any type suitable for the local technical network and may be implemented using any suitable data storage technology, such as, by way of non-limiting example, non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Although only one memory 420 is shown in the device 400, several physically separate memory modules may be present in the device 400. The processor 410 may be of any type suitable for the local technical network and may include, by way of non-limiting example, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 400 may have multiple processors, such as application-specific integrated circuit chips time-slaved to a clock that synchronizes the main processor.

[0059] When the device 400 functions as the terminal device 110, the processor 410 may perform the operations or acts of the first device 110 described above with reference to Figures 2 and 3. Details are omitted for the sake of brevity.

[0060] In general, various exemplary embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While various aspects of the exemplary embodiments of the present disclosure have been illustrated and described as block diagrams, flowcharts, or using some other graphical representations, it will be understood that the blocks, apparatus, systems, techniques, or methods described herein may be implemented in, by way of non-limiting example, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller, or other computing device, or some combination thereof.

[0061] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules and executed by a target real or virtual processor device, to perform the operations and actions described above with reference to FIGS. 1-3. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split among program modules as desired in various exemplary embodiments. The machine-executable instructions of the program modules may be executed in local or distributed devices. In a distributed device, the program modules may be located in both local and remote storage media.

[0062] Program code for performing the methods of the present disclosure may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, and when executed by the processor or controller, the functions or operations specified in the flowcharts and / or block diagrams are performed. The program code may run entirely on the machine, partially on the machine as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0063] In the context of the present disclosure, computer program code or associated data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals and computer-readable media.

[0064] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer-readable storage medium may include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0065] Furthermore, although operations are shown in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or sequentially, or that all of the operations shown be performed, to achieve desirable results. In certain situations, multitasking and parallel processing may be advantageous. Similarly, while details of several specific implementations are included in the foregoing description, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be unique to particular exemplary embodiments. Certain features that are described in the context of separate exemplary embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple exemplary embodiments separately or in any suitable subcombination.

[0066] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the present disclosure, as defined by the appended claims, is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

[0067] Various exemplary embodiments of the present technology have been described. In addition to or as an alternative to the above, the following examples are provided. Features described in any of the following examples can be utilized with any of the other examples described herein.

[0068] In some aspects, a terminal device comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to cause, using the at least one processor, the terminal device to send an indication of availability of non-small data transmission (SDT) data to a network device during an SDT procedure, monitor a response to the indication, and, in response to no response to the indication, perform an action including entering an idle or inactive state and / or initiating a connection setup or resumption request to the network device.

[0069] In some exemplary embodiments, non-SDT data includes data available on radio bearers that are not configured for SDT.

[0070] In some exemplary embodiments, the terminal device monitors the response to the indication by monitoring the response to the indication until the expiration of a monitoring timer or until a predetermined number of non-SDT data indications have been sent.

[0071] In some example embodiments, the monitoring timers include at least one of an SDT failure timer, a timer dedicated to sending indications of non-SDT data, a T319 timer, and a user equipment (UE) assistance information prohibit timer.

[0072] Some exemplary embodiments further cause the terminal device to retransmit the indication upon expiration of the timer or to retransmit the indication based on an indication from a Non-Access Stratum (NAS).

[0073] In some exemplary embodiments, the monitoring timer is started upon transmission of the indication, and / or the monitoring timer is stopped upon at least one of a cell reselection initiated by the terminal device or upon receipt of a response to the indication.

[0074] In some exemplary embodiments, the response includes at least one of an RRCResume message, an RRCSetup message, an RRCRelease message, an RRCRelease with suspendConfig message, or an RRCReject message.

[0075] In some example embodiments, the indication is sent in at least one of an RRC message, MAC signaling, PHY signaling, and UE assistance information.

[0076] In some aspects, an apparatus implemented in a terminal device includes means for transmitting an indication of availability of non-small data transmission (SDT) data to a network device during an SDT procedure, means for monitoring a response to the indication, and means for performing an action in response to no response to the indication, including entering an idle or inactive state and / or initiating a connection setup or resumption request to the network device.

[0077] In some exemplary embodiments, non-SDT data includes data available on radio bearers that are not configured for SDT.

[0078] In some exemplary embodiments, the means for monitoring a response to the indication includes means for monitoring a response to the indication until expiration of a monitoring timer or until a predetermined number of transmissions of the indication of non-SDT data.

[0079] In some example embodiments, the monitoring timers include at least one of an SDT failure timer, a timer dedicated to sending indications of non-SDT data, a T319 timer, and a user equipment (UE) assistance information prohibit timer.

[0080] In some exemplary embodiments, the apparatus further comprises means for retransmitting the indication upon expiration of the timer or means for retransmitting the indication based on an indication from a Non-Access Stratum (NAS).

[0081] In some exemplary embodiments, the monitoring timer is started upon transmission of the indication, and / or the monitoring timer is stopped upon at least one of a cell reselection initiated by the terminal device or upon receipt of a response to the indication.

[0082] In some exemplary embodiments, the response includes at least one of an RRCResume message, an RRCSetup message, an RRCRelease message, an RRCRelease with suspendConfig message, or an RRCReject message.

[0083] In some example embodiments, the indication is sent in at least one of an RRC message, MAC signaling, PHY signaling, and UE assistance information.

[0084] In some aspects, a computer-readable storage medium having instructions, when executed on at least one processor, causes the at least one processor to perform the steps of the aforementioned aspects.

Claims

1. A terminal device, at least one processor; at least one memory containing computer program code; wherein the at least one memory and the computer program code are used by the at least one processor to sending an indication of non-small data transmission (SDT) data availability to a network device in UE assistance information during an SDT procedure; monitoring a response to the indication until an SDT failure timer configured to monitor failure of the SDT procedure expires; performing an action in response to the absence of a response to the indication of the non-SDT data; wherein the action includes entering an idle state. The terminal device.

2. 2. The terminal device of claim 1, wherein the non-SDT data comprises data available on radio bearers that are not configured for SDT.

3. The terminal device, retransmitting said indication upon expiration of a timer; or retransmitting the indication based on an indication from a non-access stratum (NAS) The terminal device of claim 1 , further comprising:

4. 2. The terminal device of claim 1, wherein the SDT failure timer for the monitoring is stopped at least one of upon cell reselection initiated by the terminal device or upon receipt of the response to the indication.

5. The response: RRCResume message, RRCSetup message, RRCRelease message, an RRCReleasewithSuspendConfig message, or RRCReject Message The terminal device of claim 1 , comprising at least one of:

6. 1. A method implemented in a terminal device, comprising: sending an indication of non-small data transmission (SDT) data availability to a network device in UE assistance information during an SDT procedure; monitoring a response to the indication until an SDT failure timer configured to monitor failure of the SDT procedure expires; taking an action in response to said lack of response to said indication. wherein the action includes entering an idle state. The method.

7. 7. The method of claim 6, wherein the non-SDT data comprises data available on radio bearers that are not configured for SDT.

8. retransmitting said indication upon expiration of a timer; or retransmitting said indication based on an indication from a Non-Access Stratum (NAS); The method of claim 6 further comprising:

9. the SDT failure timer for the monitoring is stopped at least one of upon cell reselection initiated by the terminal device or upon receipt of the response to the indication; The method of claim 6.

10. The response: RRCResume message, RRCSetup message, RRCRelease message, an RRCReleasewithSuspendConfig message, or RRCReject Message The method of claim 6 , comprising at least one of:

11. 1. An apparatus implemented in a terminal device, comprising: means for transmitting an indication of non-small data transmission (SDT) data availability to a network device in UE assistance information during an SDT procedure; means for monitoring a response to said indication until an SDT failure timer configured to monitor failure of said SDT procedure expires; means for performing an action in response to said lack of response to said indication; wherein the action includes entering an idle state. The device.

12. 12. The apparatus of claim 11, wherein the non-SDT data comprises data available on radio bearers that are not configured for SDT.

13. 12. The apparatus of claim 11, wherein the SDT failure timer for the monitoring is stopped upon at least one of a cell reselection initiated by the terminal device or upon receipt of the response to the indication.

14. The response: RRCResume message, RRCSetup message, RRCRelease message, an RRCReleasewithSuspendConfig message, or RRCReject Message The apparatus of claim 11 , comprising at least one of:

15. 11. A computer-readable storage medium having stored thereon instructions that, when executed on at least one processor, cause the at least one processor to perform a method according to any one of claims 6 to 10.

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