Identification for small data transmission

Abstract

Embodiments of the present disclosure relate to identification for small data transmissions (SDT). A terminal device receives a message from a network device, the message including at least a first identifier of the terminal device for a non-small data transmission (non-SDT) process and a second identifier of the terminal device for an SDT process. Further, the terminal device transmits a request message to the network device, the request message including the first identifier or the second identifier. Therefore, additional signaling overhead can be avoided, power consumption can be saved, and transmission efficiency can be improved.

Description

Technical Field

[0001] Various example embodiments relate to the field of telecommunications, and in particular, to methods, devices, apparatus, and computer-readable storage media for identification of small data transfers (SDTs). Background Art

[0002] In New Radio (NR), in order to avoid the signaling overhead and delay associated with the state transition of the user equipment (UE) from the radio resource control inactive (RRC_inactive) state to the RRC_connected state, a transmission scheme called SDT has been proposed to facilitate data transmission. In SDT, data exchange between the base station and the UE can be achieved when the UE is in the RRC_inactive state during transmission. However, there are still some open issues in SDT, which will be studied in the near future. Summary of the invention

[0003] Generally speaking, example embodiments of the present disclosure provide schemes related to identification for SDT.

[0004] In a first aspect, a terminal device is provided. The terminal device comprises at least one processor (non-SDT) and at least one memory, wherein the at least one memory stores instructions, and when the instructions are executed by the at least one processor, the terminal device at least: receives a message from a network device, the message at least comprising a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process; and sends a request message to the network device, the request message comprising the first identifier or the second identifier.

[0005] In a second aspect, a network device is provided. The network device includes at least one processor and at least one memory, wherein the at least one memory stores instructions, and when the instructions are executed by the at least one processor, the network device at least: sends a message to a terminal device, wherein the message includes at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process; and receives a request message from the terminal device, wherein the request message includes the first identifier or the second identifier non-SDT.

[0006] In a third aspect, a method implemented at a terminal device is provided. The method comprises: receiving a message from a network device, the message comprising at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process; non-SDT; and sending a request message to the network device, the request message comprising the first identifier or the second identifier.

[0007] In a fourth aspect, a method implemented at a network device is provided. The method comprises: sending a message to a terminal device, the message comprising at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process; and receiving a request message from the terminal device, the request message comprising the first identifier or the second identifier.

[0008] In a fifth aspect, an apparatus is provided. The apparatus comprises: a component for receiving a message from a network device at a terminal device, the message comprising at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process; and a component for sending a request message to the network device, the request message comprising the first identifier or the second identifier.

[0009] In a sixth aspect, an apparatus is provided. The apparatus comprises: a component for sending a message to a terminal device at a network device, the message comprising at least a first identifier of the terminal device for a non-small data transfer (non-SDT) procedure and a second identifier of the terminal device for an SDT procedure; and a component for receiving a request message from the terminal device, the request message comprising the first identifier or the second identifier.

[0010] In a seventh aspect, a non-transitory computer-readable medium is provided, comprising program instructions for causing an apparatus to at least execute a method according to any one of the third to fourth aspects above.

[0011] In an eighth aspect, a computer program is provided, comprising instructions, which, when executed by a device, cause the device to at least perform a method according to any one of the third to fourth aspects above.

[0012] In a ninth aspect, a terminal device is provided. The terminal device comprises: a receiving circuit configured to receive a message from a network device, the message comprising at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process (non-SDT); and a sending circuit configured to send a request message to the network device, the request message comprising the first identifier or the second identifier.

[0013] In a tenth aspect, a network device is provided. The network device comprises: a sending circuit configured to send a message to a terminal device, the message comprising at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process (non-SDT); and a receiving circuit configured to receive a request message from the terminal device, the request message comprising the first identifier or the second identifier.

[0014] It should be understood that the summary is not intended to identify the key or essential features of the embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0016] Figure 1 An example environment is shown in which example embodiments of the present disclosure may be implemented;

[0017] Figure 2 shows a signaling flow between a terminal device and a network device according to some example embodiments of the present disclosure;

[0018] Figure 3 An example communication process between a terminal device and a network device according to some example embodiments of the present disclosure is shown;

[0019] Figure 4 A flowchart of a method implemented at a terminal device according to some embodiments of the present disclosure is shown;

[0020] Figure 5 A flowchart of a method implemented at a network device according to some embodiments of the present disclosure is shown;

[0021] Figure 6 shows a simplified block diagram of a device suitable for implementing some example embodiments of the present disclosure; and

[0022] Figure 7 A block diagram illustrating an example of a computer readable medium according to some example embodiments of the present disclosure is shown.

[0023] Throughout the drawings, the same or similar reference numerals refer to the same or similar elements. DETAILED DESCRIPTION

[0024] The principle of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described only for illustrative purposes, and help those skilled in the art to understand and implement the present disclosure, without implying any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in various ways except for the way described below.

[0025] In the following description and claims, unless defined otherwise, 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.

[0026] References in this disclosure to "one embodiment," "an embodiment," "an example embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, it is considered to be within the knowledge of those skilled in the art to affect such feature, structure, or characteristic in conjunction with other embodiments, whether or not explicitly described.

[0027] It should be understood that although the terms "first" and "second" etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the example embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0028] The terms used herein are only used to describe the purpose of a particular embodiment, and are not intended to limit example embodiments. As used herein, the singular forms "one", "an" and "the" are also intended to include plural forms, unless the context clearly indicates otherwise. It will be further understood that the terms "include", "include", "have", "contain", "include" and / or "include" specify the existence of stated features, elements and / or components when used herein, but do not exclude the existence or addition of one or more other features, elements, components and / or their combinations. As used herein, "at least one of the following: <list of two or more elements>" and "at least one of <list of two or more elements>" and similar wording, wherein the list of two or more elements is combined by "and" or "or", meaning at least any one of the elements, or at least any two or more of the elements, or at least all elements.

[0029] As used in this application, the term "circuitry" may refer to one or more or all of the following: (a) hardware circuit implementation only (such as implementation in analog and / or digital circuitry only) and (b) a combination of hardware circuitry and software such as (if applicable): (i) A combination of analog and / or digital hardware circuits with software / firmware (ii) any portion of hardware processor(s) (including digital signal processor(s)), software and memory(s) with software that work together to enable a device such as a mobile phone or server to perform various functions, and (c) hardware circuit(s) and / or processor(s) such as microprocessor(s) or portion(s) of microprocessor(s) that require software (e.g., firmware) for operation, but which may not be present when the software is not required for operation.

[0030] This definition of circuitry applies to all uses of the term in this application, including any claims. As another example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or its) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0031] As used herein, the term "communication network" refers to a network that complies with any suitable communication standard, such as Long Term Evolution (LTE), Advanced LTE (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. In addition, the communication between the terminal equipment and the network equipment in the communication network can be performed according to any suitable generation of communication protocols, including but not limited to the third generation (3G), fourth generation (4G), 4.5G, future fifth generation (5G) communication protocols and / or any other protocols currently known or developed in the future. The embodiments of the present disclosure can be applied to various communication systems. In view of the rapid development of communication, there will certainly be future types of communication technologies and systems that can embody the present disclosure. It should not be considered that the scope of the present disclosure is limited to the aforementioned system.

[0032] As used herein, the term "network device" refers to a node in a communication network via which a terminal device accesses the network and receives services from it. Depending on the terminology and technology applied, a network device may refer to a base station (BS) or an access point (AP), for example, a Node B (Node B or NB), an evolved Node B (e Node B or eNB), a new radio (NR) NB (also known as a gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, a low power node (such as a femto, a pico, etc.).

[0033] The term "terminal device" refers to any terminal device capable of wireless communication. As an example and not limitation, a terminal device may also be referred to as a communication device, a user equipment (UE), a subscriber station (SS), a portable subscriber station, a mobile station (MS), or an access terminal (AT). The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smart phone, a voice over IP (VoIP) phone, a wireless local ring phone, a tablet computer, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device such as a digital camera, a game terminal device, a music storage and playback device, a vehicle-mounted wireless terminal device, a wireless endpoint, a mobile station, a laptop embedded device (LEE), a laptop mounted device (LME), a USB dongle, a smart device, a wireless customer premises equipment (CPE), an Internet of Things (IoT) device, a watch or other wearable device, a head mounted display (HMD), a vehicle, a drone, medical equipment and applications (e.g., remote surgery), industrial equipment and applications (e.g., robots and / or other wireless devices operating in the context of an industrial and / or automated processing chain), consumer electronic devices, equipment operating on a commercial and / or industrial wireless network, etc. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

[0034] For mobile originated (MO) SDT, the UE may indicate the initiation of the SDT procedure via dedicated RACH resources that the NW may have configured. If no such RACH resources exist (i.e., SDT also uses common RACH resources that are not reserved or configured for SDT), the network equipment may infer the need for SDT from the buffer status report (BSR) indicated by the UE in message 3 (Msg3) of the random access procedure, only if there is enough space after including a common control channel (CCCH) service data unit (SDU) / RRC recovery request, or then after a successful contention resolution of the random access procedure. On the other hand, this solution similarly affects legacy UEs / other UEs that do not perform SDT, as these UEs will also need to report a BSR with zero UL buffer and consume power for unnecessary uplink transmissions.

[0035] In addition, for MO-SDT, the UE evaluates whether it can trigger the SDT procedure based on the data volume threshold and (if configured) the reference signal received power (RSRP) of the communication link, as specified in the following 3rd Generation Partnership Project (3GPP) Technical Specification (TS) 38.321 v17.2.0:

[0036] In addition, new work items for Mobile Terminated (MT) SDT for NR have been discussed. The following summarizes the adjustments and objectives of the work:

[0037] Paging the UE in RRC_Inactive with I-RNTI. In order to enable the UE to indicate the initiation of the resumption procedure for a regular resumption procedure or as a response to MT-SDT paging, a solution may be to use a new resumeCause to indicate that the initiation is for MT-SDT or any other reason, such as Long Term Evolution (LTE) MT Early Data Transfer (EDT).

[0038] However, this solution leads to additional paging overhead issues. Although only 1 bit of cause value overhead may be added to the paging message for each transmitted UE MT-SDT paging, a nonCriticalExtension is required from previous versions, which may not be preferred in 3GPP because such resumeCause is not introduced for MO-SDT use cases either.

[0039] However, any additional information included in the paging record will increase the overhead of the paging procedure within the entire UE RAN Notification Area (RNA) within each beam of the cell.

[0040] Therefore, there is currently no effective way to provide paging for MT-SDT for a UE and enable the UE to indicate the initiation of a recovery procedure for either a normal recovery procedure (ie, a non-SDT recovery procedure) or an SDT recovery procedure.

[0041] According to an embodiment of the present disclosure, a scheme for identification for MT-SDT paging purposes and SDT initiation is provided. Using this scheme, a terminal device receives a message from a network device, the message including at least a first identifier of the terminal device for a non-small data transmission (non-SDT) process and a second identifier of the terminal device for an SDT process, non-SDT. And, the terminal device sends a request message to the network device, the request message including the first identifier or the second identifier.

[0042] The solution optimizes the identification used for SDT by including different identifiers in the request message to the network device. In this way, additional signaling overhead can be avoided, power consumption can be saved, and transmission efficiency can be improved.

[0043] The principles and embodiments of the present invention are described in detail below with reference to the accompanying drawings. Figure 1 , which illustrates an example environment 100 in which example embodiments of the present disclosure may be implemented.

[0044] The environment 100 , which may be part of a communication network, includes a terminal device 110 and a network device 120 that communicate with each other or with other devices via each other.

[0045] The communication environment 100 may include any suitable number of devices and cells. In the communication environment 100, the terminal device 110 and the network device 120 may transmit data and control information to each other. The link from the network device 120 to the terminal device 110 is called a downlink (DL), and the link from the terminal device 110 to the network device 120 is called an uplink (UL).

[0046] It should be understood that two devices are shown in environment 100 for illustration purposes only and does not imply any limitation on the scope of the present disclosure. In some example embodiments, environment 100 may include another device in communication with terminal device 110 and network device 120.

[0047] Communications in environment 100 may follow any suitable communication standards or protocols that already exist or will be developed in the future, such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), Advanced LTE (LTE-A), Fifth Generation (5G) New Radio (NR), Wireless Fidelity (Wi-Fi), and Worldwide Interoperability for Microwave Access (Wi MAX) standards, and employ any suitable communication technology, including, for example, 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 Communication (MTC), Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), Ultra-Reliable Low Latency Communication (URLLC), Carrier Aggregation (CA), Dual Connectivity (DC), and New Radio Unlicensed (NR-U) technologies.

[0048] Figure 2 2 shows a signaling flow 200 between a terminal device and a network device according to some example embodiments of the present disclosure. For the purpose of discussion, reference will be made to Figure 1 The signaling flow 200 is described.

[0049] like Figure 2 As shown, the network device 120 sends (205) a message to the terminal device 110, the message including at least a first identifier of the terminal device 110 for the non-SDT process and a second identifier of the terminal device for the SDT process. Therefore, the terminal device 110 receives (210) a message from the network device 120. For example, the message may be a release message, such as an RRC release message, to indicate that the terminal device 110 enters an RRC_inactive state or an RRC_idle state. As an example, the non-SDT process may be a non-SDT recovery process, also referred to as a conventional recovery process, and the SDT process may be an SDT recovery process. The non-SDT recovery process may include a conventional RRC recovery process, in which the UE moves from the RRC_inactive state to the RRC_connected state. As another example, the message may be a reconfiguration message, such as an RRC reconfiguration message.

[0050] In some example embodiments, the first and second identifiers may be inactive radio network temporary identifiers (I-RNTIs). For example, the first and second identifiers may be full I-RNTIs. As another example, the first and second identifiers may be short I-RNTIs. As another example, the first and second identifiers may be S-temporary mobile subscriber identities (S-TMSIs). In some example embodiments, if only the first identifier is configured as a short I-RNTI and the second identifier is not configured, the terminal device 110 may only initiate a conventional SDT procedure.

[0051] The terminal device 110 sends (215) a request message including the first identifier or the second identifier to the network device 120. Therefore, the network device receives (220) the request message from the terminal device 110. For example, the request message may be a recovery request message. In this case, as an example, the recovery request message may be used to initiate an MT-SDT recovery process, an MO-SDT recovery process, or a conventional recovery process. For another example, the request message may be an establishment request message.

[0052] In some example embodiments, before receiving the request message, the network device 120 may send a paging message to the terminal device 110. The paging message may include the first or second identifier.

[0053] In some example embodiments, if the paging message includes the first identifier, the terminal device 110 may send a request message including the first identifier to the network device 120 as a response to the paging message. In this case, before sending the request message including the first identifier, the terminal device 110 may initiate a non-SDT recovery procedure. For example, at least one RACH resource that is not configured for SDT (also referred to as a common RACH resource) may be used to initiate a non-SDT recovery procedure.

[0054] In some other example embodiments, if the paging message includes a second identifier, the terminal device 110 may send a request message including the second identifier to the network device 120 as a response to the paging message. In this case, before sending the request message including the second identifier, the terminal device 110 may initiate an SDT recovery procedure. When initiating the SDT recovery procedure, the terminal device 110 may recover a data radio bearer (DRB) / signaling radio bearer (SRB) configured for SDT. For example, at least one RACH resource that is not configured for SDT may be used for the initiation of the SDT procedure so that MO-SDT in the cell does not need to be a prerequisite for enabling MT-SDT. Accordingly, on the network side, based on the second identifier in the request message, the network device 120 may determine that the SDT recovery procedure is initiated on at least one RACH resource that is not configured for SDT.

[0055] In this case, since the terminal device 110 may or may not have any uplink SDT data to be sent, it would not be necessary to use at least one RACH resource configured for SDT (if configured) in the case where the terminal device 110 does not have any uplink SDT data to be sent, as the network may allocate a larger amount of resources for Msg3 transmission to fit at least a portion of the uplink SDT data into it. It would appear to be beneficial to allow the terminal device 110 to initiate an SDT procedure with MT-SDT access using normal RACH resources that are not configured for SDT, so that the network device 120 can use the Msg3 resources in the case where no uplink SDT data is available.

[0056] As an example, the second identifier may be an MT-SDT specific identifier (e.g., an I-RNTI). In this case, the network device 120 may instruct the terminal device 110 to initiate MT-SDT using the MT-SDT specific identifier in the paging message or the MT-SDT specific identifier in the paging record. For example, if an MT-SDT specific identifier is received in the paging message, the terminal device 110 may initiate an MT-SDT recovery procedure, and if a conventional identifier is received, the terminal device 110 may initiate a conventional non-SDT recovery procedure. Therefore, this does not expose any additional overhead to be introduced into the paging message for MT-SDT purposes, and thus the legacy paging message may be reused.

[0057] In some example embodiments, the initiation of the SDT / non-SDT process may also be based on other condition checks on the terminal device side. For example, the condition check may include RSRP check, UL data check, etc. In the case where the terminal device 110 is in a worse channel condition than the RSRP threshold allows, the RSRP check may be used to ensure successful transmission of downlink data, for example, by using a non-SDT process in this case.

[0058] As an example, after receiving the paging message, the terminal device 110 may also determine whether there is uplink data in the cache and / or whether the RSRP of the communication link is higher than the RSRP threshold. For example, the RSRP threshold may be configured or predefined by the network device 120. As an example, the RSRP threshold for MT-SDT may be different from the RSRP threshold for MO-SDT. As an example, the network device 120 may configure the RSRP threshold for MT-SDT to be different from the RSRP threshold for MO-SDT.

[0059] In some example embodiments, after receiving a paging message including a second identifier, if the terminal device 110 determines that there is no uplink SDT data in the buffer or the RSRP of the communication link is lower than the RSRP threshold, it may initiate a non-SDT process on at least one RACH resource that is not configured for SDT. As another example, if the terminal device 110 determines that there is uplink non-SDT data in the buffer, it may also initiate a non-SDT process on at least one RACH resource that is not configured for SDT. The request message sent to the network device 120 may include a first identifier to indicate that a non-SDT process is required. Then, accordingly, on the network side, the network device 120, after sending a paging message including a second identifier, may determine that the RSRP of the communication link at the terminal device 110 is lower than the RSRP threshold or there is uplink non-SDT data to be sent at the terminal device 110 based on determining that a non-SDT process is initiated on at least one RACH resource that is not configured for SDT and the received request message includes the first identifier. Then, the network device 120 may configure the terminal device 110 to enter a connected state. For example, the network device 120 may send a recovery message to the terminal device 110 .

[0060] For example, in this case, the terminal device may also set a cause in the request message to indicate the reason for initiating the non-SDT process.

[0061] After receiving the paging message including the second identifier, if the terminal device 110 determines that there is no uplink data in the buffer and the RSRP of the communication link is below the RSRP threshold, the cause in the request message may be set to a first cause value (e.g., mt-Access resumeCause) indicating that a non-SDT process is used for MT access or MT data. For example, the terminal device 110 may resume the SDT bearer before sending the request message, which includes the first identifier with the first cause value. As an example, in this case, the network device 120 may send SDT data to the terminal device 110 without configuring the terminal device 110 to enter a connected state. In other words, in this case, the network device 120 may attempt to send DL SDT data without bringing the terminal device 110 to the RRC_Connected state, even if it knows that the RSRP measured at the terminal device 110 is below the RSRP threshold.

[0062] Otherwise, after receiving the paging message including the second identifier, if the terminal device 110 determines that there is uplink non-SDT data in the buffer, the cause in the request message can be set to a second cause value (e.g., mo-data resume Cause) indicating that the non-SDT process is used for MO access or MO data. Therefore, based on the request message with the second cause value, the network device 120 can determine that there is uplink non-SDT data to be sent at the terminal device 110.

[0063] In some example embodiments, after receiving the paging message including the second identifier, if the terminal device 110 determines that there is no uplink SDT data in the buffer, the SDT process may be initiated on at least one RACH resource that is not configured for SDT, and then a request message including the second identifier may be sent to the network device 120. As an example, the terminal device 120 may further initiate the SDT process based on the RSRP of the communication link. For example, if the terminal device 110 determines that the RSRP of the communication link is higher than the RSRP threshold, it may initiate the SDT process. Alternatively or additionally, if the terminal device 110 determines that there is no uplink SDT data in the buffer and the RSRP of the communication link is lower than the RSRP threshold, the terminal device 110 may initiate the SDT procedure. On the network side, based on determining that the SDT process is initiated on at least one RACH resource that is not configured for SDT and the received request message includes the second identifier, the network device 120 may determine that there is no uplink SDT data to be sent at the terminal device 110, and then send the SDT data to the terminal device 110 without configuring the terminal device 110 in a connected state.

[0064] In some example embodiments, after receiving the paging message including the second identifier, if the terminal device 110 determines that there is uplink SDT data in the buffer, an SDT procedure may be initiated on at least one RACH resource configured for SDT, and then a request message including the second identifier may be sent to the network device 120. As an example, the terminal device 120 may further initiate the SDT procedure based on the RSRP of the communication link. For example, if the terminal device 110 determines that there is uplink SDT data in the buffer and the RSRP of the communication link is above the RSRP threshold, the terminal device 110 may initiate the SDT procedure. Alternatively or additionally, if the terminal device 110 determines that there is uplink SDT data in the buffer and the RSRP of the communication link is below the RSRP threshold, the terminal device 110 may initiate the SDT procedure. On the network side, based on determining that the SDT process is initiated on at least one RACH resource configured for SDT and the received request message includes a second identifier, the network device 120 can determine that there is uplink SDT data to be sent at the terminal device 110 and that the terminal device 110 has received a paging message including the second identifier.

[0065] In some exemplary embodiments, if the terminal device 120 determines that there is uplink SDT data in the buffer and the RSRP of the communication link is higher than the RSRP threshold, the SDT process may be initiated on at least one RACH resource configured for SDT, and then a request message including the first identifier may be sent to the network device 120. In this case, for example, if the network device 120 has sent a paging message including the second identifier to the terminal device 110, it may be determined that the terminal device 120 has not received the paging message.

[0066] In some example embodiments, after receiving a paging message including a first identifier, the terminal device 110 may initiate a non-SDT process on at least one RACH resource that is not configured for SDT, and then send a request message including the first identifier to the network device 120. For example, there may be no UL-SDT data in the buffer. In this case, the second specific identifier may not be used, although it is allocated. As another example, there may be UL-SDT data in the buffer. In this case, although the second identifier is allocated, the second identifier may not be used because the network device 120 has paged the terminal device 110 to use the non-SDT process. Therefore, on the network side, the network device 120 may determine to initiate a non-SDT process on at least one RACH resource that is not configured for SDT. The following non-SDT process may continue.

[0067] In some example embodiments, the above identifiers may be applied to the MO-SDT case. In this case, the second identifier may be used by the terminal device 110 for MO-SDT on at least one RACH resource that is not configured for SDT. For example, the network device 120 may indicate a MO-SDT configuration in a cell, but may not provide any SDT-specific RACH resources. Then, if the conditions for initiating MO-SDT are met (e.g., an RSRP threshold is met, as explained in the next paragraph), the terminal device 110 may initiate an SDT process on at least one RACH resource that is not configured for SDT, and use the second identifier in the request message to indicate that the initiation is for MO-SDT.

[0068] In this case, for example, before sending the request message, if the terminal device determines that there is uplink SDT data in the buffer, and can further determine that the RSRP of the communication link is higher than the RSRP threshold, the SDT process can be initiated on at least one RACH resource that is not configured for SDT, and then a request message including the second identifier is sent to the network device 120. In other words, the SDT process is an MO-SDT process. Therefore, the network device 120 can determine that the SDT process is initiated on at least one RACH resource that is not configured for SDT, and then determine that the SDT process is an MO-SDT process based on the second identifier.

[0069] In this way, a simple and efficient mechanism can be used to provide paging for SDT and identification for initiating an SDT process or a conventional non-SDT process based on different identifiers. Compared with a conventional RRC process (e.g., a conventional RRC recovery process), no additional overhead is exposed to any downlink or uplink RRC message to initiate an SDT process (e.g., an MT-SDT specific recovery process). In addition, depending on different conditions on the terminal device side, some cause values ​​(e.g., the current resumeCause value) can be used to indicate other information useful to the network device 120.

[0070] Figure 3 FIG. 3 shows an example communication process 300 between a terminal device and a network device according to some example embodiments of the present disclosure. For the purpose of discussion, reference will be made to FIG. Figure 1 Describe process 300. It should be understood that although Figure 1 The process 300 is described in the network environment 100 of FIG. 1 , but the process flow can be equally applied to other communication scenarios. In this case, the terminal device 110 is implemented by UE 301 and the network device 120 is implemented by gNB 303.

[0071] like Figure 3As shown, at 304, gNB 303 sends an RRC release message with multiple identifiers to UE 301, the multiple identifiers including at least a first identifier and a second identifier. For example, the identifier is an I-RNTI. In this case, the first identifier is also called a regular I-RNTI, and the second identifier is also called an MT-SDT specific I-RNTI.

[0072] At 306, UE 301 enters RRC_INACTIVE state and stores the above I-RNTI. At 308, downlink SDT data becomes available. Then, at 310, gNB 303 sends a paging message with MT-SDT specific I-RNTI to UE 301.

[0073] At 312, UE 301 determines that gNB 303 has downlink SDT data to be sent. At 314, UE 301 may further determine that the measured RSRP>=RSRP threshold and no uplink SDT data is available.

[0074] Then, at 316, UE 301 initiates a random access (RA) procedure on a common RACH resource that is not configured for SDT. At 318, UE 301 sends an RRC recovery request message with an MT-SDT specific I-RNTI to gNB 303.

[0075] At 320, SDT data in the downlink is sent, and subsequent uplink SDT data (if any) may be sent. At 322, similar to step 304, gNB 303 may send an RRC release message with multiple I-RNTIs including regular and MT-SDT specific I-RNTIs.

[0076] References Figure 2 All operations and features described are equally applicable to process 300 and have similar effects. For the sake of simplicity, details will be omitted.

[0077] Figure 4 4 is a flowchart 400 showing a method implemented at a terminal device 110 according to some embodiments of the present disclosure. For the purpose of discussion, reference will be made to Figure 1 The method 400 is described from the perspective of the terminal device 110 .

[0078] At block 410, terminal device 110 receives a message from network device 120, the message including at least a first identifier of terminal device 110 for a non-small data transfer (non-SDT) procedure and a second identifier of terminal device 110 for an SDT procedure. At block 420, terminal device 110 sends a request message to network device 120, the request message including the first identifier or the second identifier.

[0079] In some exemplary embodiments, the terminal device 110 sends the request message by: sending the request message including the second identifier to the network device 120 based on receiving the paging message including the second identifier from the network device 120. In some exemplary embodiments, the terminal device 110 also initiates the SDT process on at least one random access channel RACH resource that is not configured for SDT before sending the request message including the second identifier. In some exemplary embodiments, the terminal device 110 initiates the SDT process by: initiating the SDT process on the at least one RACH resource that is not configured for SDT based on determining that there is no uplink SDT data in the buffer. In some exemplary embodiments, the terminal device 110 also initiates the SDT process on the at least one RACH resource that is configured for SDT based on determining that there is uplink SDT data in the buffer before sending the request message including the second identifier. In some exemplary embodiments, the terminal device 110 initiates the SDT process by: initiating the SDT process further based on a reference signal received power (RSRP) of the communication link being higher than an RSRP threshold. In some exemplary embodiments, the terminal device 110 initiates the SDT process by: initiating the SDT process further based on the RSRP of the communication link being lower than an RSRP threshold.

[0080] In some exemplary embodiments, the terminal device 110 further receives a paging message including a second identifier from the network device 120; and before sending the request message, based on determining that there is no uplink SDT data in the buffer and the RSRP of the communication link is lower than the RSRP threshold or there is uplink non-SDT data in the buffer, the non-SDT process is initiated on at least one RACH resource that is not configured for SDT. In some exemplary embodiments, the terminal device 110 sends the request message by: sending a request message including the first identifier to the network device 120. In some exemplary embodiments, the terminal device 110 further sets the cause in the request message to a first cause value based on determining that there is no uplink data in the buffer and the RSRP of the communication link is lower than the RSRP threshold, and the first cause value indicates that the non-SDT process is used for mobile terminated (MT) access. In some exemplary embodiments, the terminal device 110 further sets the cause in the request message to a second cause value based on determining that there is uplink non-SDT data in the buffer, and the second cause value indicates that the non-SDT process is used for mobile initiated (MO) access.

[0081] In some exemplary embodiments, the terminal device 110 also receives a paging message including a first identifier from the network device 120; and initiates a non-SDT process on at least one RACH resource that is not configured for SDT, and the terminal device 110 sends a request message by: sending a request message including the first identifier to the network device 120.

[0082] In some example embodiments, the terminal device 110 also initiates an SDT process on at least one RACH resource that is not configured for SDT before sending the request message based on determining that there is uplink SDT data in the buffer and that the RSRP of the communication link is higher than an RSRP threshold, the SDT process being a mobile initiated (MO)-SDT process, and the terminal device 110 sends the request message by sending a request message including a second identifier to the network device 120.

[0083] In some example embodiments, the RSRP threshold for MT-SDT is different from the RSRP threshold for MO-SDT.

[0084] In some example embodiments, the first identifier and the second identifier are a completely inactive radio network temporary identifier (I-RNTI) or a short I-RNTI for the SDT procedure.

[0085] In some example embodiments, the message is a release message or a reconfiguration message.

[0086] Figure 5Flowchart 500 of a method implemented at network device 120 according to some embodiments of the present disclosure is shown. For discussion purposes, reference will be made to Figure 1 Method 500 is described from the perspective of network device 120 .

[0087] At block 510, network device 120 sends a message to terminal device 110, the message including at least a first identifier of terminal device 110 for a non-small data transfer (non-SDT) procedure and a second identifier of terminal device 110 for an SDT procedure. At block 520, network device 120 receives a request message from terminal device 110, the request message including the first identifier or the second identifier.

[0088] In some example embodiments, the network device 120 further sends a paging message including the second identifier to the terminal device 110 before receiving the request message.

[0089] In some example embodiments, the network device 120 further determines, after sending the paging message including the second identifier, that the SDT process is initiated on at least one random access channel, RACH, resource not configured for SDT.

[0090] In some example embodiments, the network device 120 further determines, after sending the paging message including the second identifier, that a reference signal received power (RSRP) of a communication link at the terminal device 110 is below an RSRP threshold or that there is uplink non-SDT data to be sent at the terminal device 110 based on determining that a non-SDT process is initiated on at least one RACH resource that is not configured for SDT and that the received request message includes the first identifier; and configures the terminal device 110 to enter a connected state. In some example embodiments, the network device 120 determines that there is uplink non-SDT data to be sent at the terminal device 110 by: determining that there is uplink non-SDT data to be sent at the terminal device 110 based on determining that a cause in the request message is set to a second cause value, the second cause value indicating that the non-SDT process is for mobile originated (MO) access. In some example embodiments, the RSRP threshold for MT-SDT is different from the RSRP threshold for MO-SDT.

[0091] In some example embodiments, the network device 120 also determines, after sending a paging message including a second identifier, that a non-SDT process is initiated on at least one RACH resource that is not configured for SDT, and that the received request message includes a first identifier; determines that a cause in the request message is set to a first cause value, the first cause value indicating that the non-SDT process is used for mobile terminated (MT) access; and sends SDT data to the terminal device 110 without configuring the terminal device 110 to enter a connected state.

[0092] In some example embodiments, network device 120 also determines, after sending a paging message including a second identifier, that there is no uplink SDT data to be sent at terminal device 110 based on determining that the SDT process is initiated on at least one RACH resource that is not configured for SDT, and that the received request message includes the second identifier; and sends SDT data to terminal device 110 without configuring terminal device 110 to be in a connected state.

[0093] In some example embodiments, network device 120 also determines, after sending a paging message including the second identifier, that there is uplink SDT data to be sent at terminal device 110, and that terminal device 110 has received the paging message including the second identifier, based on determining that an SDT process is initiated on at least one RACH resource configured for SDT, and that the received request message includes the second identifier.

[0094] In some example embodiments, the network device 120 also sends a paging message including the first identifier to the terminal device 110 before receiving the request message, and after sending the paging message including the first identifier, determines that a non-SDT process is initiated on at least one RACH resource that is not configured for SDT.

[0095] In some example embodiments, network device 120 further determines, prior to receiving the request message including the second identifier, that the SDT procedure is initiated on at least one RACH resource not configured for SDT, the SDT procedure being a Mobile Originated (MO)-SDT procedure.

[0096] In some example embodiments, the first identifier and the second identifier are a completely inactive radio network temporary identifier (I-RNTI) or a short I-RNTI for the SDT procedure.

[0097] In some example embodiments, the message is a release message or a reconfiguration message.

[0098] In some example embodiments, an apparatus capable of executing method 400 (eg, terminal device 110) may include a component for executing the corresponding steps of method 400. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit or a software module.

[0099] In some example embodiments, the apparatus includes: a component for receiving a message from a network device at a terminal device, the message including at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process; and a component for sending a request message to the network device, the request message including the first identifier or the second identifier.

[0100] In some example embodiments, the means for sending the request message includes means for sending the request message including the second identifier to the network device based on receiving a paging message including the second identifier from the network device. In some example embodiments, the apparatus further includes means for initiating an SDT process on at least one random access channel RACH resource that is not configured for SDT before sending the request message including the second identifier. In some example embodiments, the means for initiating the SDT process includes means for initiating the SDT process on at least one RACH resource that is not configured for SDT based on determining that there is no uplink SDT data in the buffer. In some example embodiments, the apparatus further includes means for initiating the SDT process on at least one RACH resource that is configured for SDT based on determining that there is uplink SDT data in the buffer before sending the request message including the second identifier. In some example embodiments, the means for initiating the SDT process includes means for initiating the SDT process further based on a reference signal received power (RSRP) of the communication link being above an RSRP threshold. In some example embodiments, means for initiating the SDT procedure includes means for initiating the SDT procedure further based on the RSRP of the communication link being below an RSRP threshold.

[0101] In some example embodiments, the apparatus further comprises: a component for receiving a paging message including a second identifier from a network device; and a component for initiating a non-SDT process on at least one RACH resource that is not configured for SDT based on determining that there is no uplink SDT data in the buffer and the RSRP of the communication link is below the RSRP threshold or there is uplink non-SDT data in the buffer before sending the request message. In some example embodiments, the component for sending the request message comprises a component for sending a request message including the first identifier to the network device. In some example embodiments, the apparatus further comprises a component for setting the cause in the request message to a first cause value indicating that the non-SDT process is used for mobile terminated (MT) access based on determining that there is no uplink data in the buffer and the RSRP of the communication link is below the RSRP threshold. In some example embodiments, the apparatus further comprises a component for setting the cause in the request message to a second cause value indicating that the non-SDT process is used for mobile originated (MO) access based on determining that there is uplink non-SDT data in the buffer.

[0102] In some example embodiments, the apparatus further comprises means for receiving a paging message including a first identifier from a network device; and means for initiating a non-SDT procedure on at least one RACH resource that is not configured for SDT, and the means for sending a request message comprises means for sending a request message including the first identifier to the network device.

[0103] In some example embodiments, the apparatus further comprises: means for initiating an SDT process on at least one RACH resource not configured for SDT, based on determining that uplink SDT data is present in the buffer and the RSRP of the communication link is above an RSRP threshold before sending the request message, the SDT process being a mobile initiated (MO)-SDT process, and the means for sending the request message comprises means for sending the request message including the second identifier to the network device.

[0104] In some example embodiments, the RSRP threshold for MT-SDT is different from the RSRP threshold for MO-SDT.

[0105] In some example embodiments, the first identifier and the second identifier are a completely inactive radio network temporary identifier (I-RNTI) or a short I-RNTI for the SDT procedure.

[0106] In some example embodiments, the message is a release message or a reconfiguration message.

[0107] In some example embodiments, the apparatus further comprises means for performing other steps in some embodiments of method 400. In some embodiments, the means comprises at least one processor and at least one memory comprising computer program code. The at least one memory and the computer program code are configured to cause execution of the apparatus together with the at least one processor.

[0108] In some example embodiments, an apparatus capable of performing method 500 (e.g., network device 120) may include components for performing the corresponding steps of method 500. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit or a software module.

[0109] In some example embodiments, the apparatus includes: a component for sending a message to a terminal device, the message including at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process; and a component for receiving a request message from the terminal device, the request message including the first identifier or the second identifier.

[0110] In some example embodiments, the apparatus further comprises means for sending a paging message including the second identifier to the terminal device prior to receiving the request message.

[0111] In some example embodiments, the apparatus further comprises means for determining, after sending the paging message including the second identifier, that the SDT process is initiated on at least one random access channel (RACH) resource not configured for SDT.

[0112] In some example embodiments, the apparatus further comprises: a component for determining, after sending a paging message including a second identifier, that a reference signal received power (RSRP) of a communication link at a terminal device is lower than an RSRP threshold or that there is uplink non-SDT data to be sent at the terminal device, based on determining that a non-SDT process is initiated on at least one RACH resource that is not configured for SDT and that the received request message includes the first identifier; and a component for configuring the terminal device to enter a connected state. In some example embodiments, the component for determining that there is uplink non-SDT data to be sent at the terminal device comprises: a component for determining that there is uplink non-SDT data to be sent at the terminal device, based on determining that a cause in the request message is set to a second cause value, the second cause value indicating that the non-SDT process is for mobile originated (MO) access. In some example embodiments, the RSRP threshold for MT-SDT is different from the RSRP threshold for MO-SDT.

[0113] In some example embodiments, the apparatus further comprises: a component for determining, after sending the paging message including the second identifier, that the non-SDT process is initiated on at least one RACH resource that is not configured for SDT, and that the received request message includes the first identifier; a component for determining that the cause in the request message is set to a first cause value, the first cause value indicating that the non-SDT process is used for mobile terminated (MT) access; and a component for sending SDT data to the terminal device without configuring the terminal device to enter a connected state.

[0114] In some example embodiments, the apparatus further comprises: a component for determining, after sending a paging message including a second identifier, that there is no uplink SDT data to be sent at a terminal device based on determining that an SDT process is initiated on at least one RACH resource that is not configured for SDT and that the received request message includes the second identifier; and a component for sending SDT data to the terminal device without configuring the terminal device to be in a connected state.

[0115] In some example embodiments, the apparatus further comprises a component for determining, after sending a paging message including the second identifier, that there is uplink SDT data to be sent at the terminal device and that the terminal device has received the paging message including the second identifier, based on determining that the SDT process is initiated on at least one RACH resource configured for SDT and that the received request message includes the second identifier.

[0116] In some example embodiments, the apparatus further comprises: a component for sending a paging message including a first identifier to a terminal device before receiving a request message; and a component for determining, after sending the paging message including the first identifier, that the non-SDT process is initiated on at least one RACH resource that is not configured for SDT.

[0117] In some example embodiments, the apparatus further comprises means for determining, prior to receiving the request message comprising the second identifier, that the SDT process is initiated on at least one RACH resource not configured for SDT, the SDT process being a mobile originated (MO)-SDT process.

[0118] In some example embodiments, the first identifier and the second identifier are a completely inactive radio network temporary identifier (I-RNTI) or a short I-RNTI for the SDT procedure.

[0119] In some example embodiments, the message is a release message or a reconfiguration message.

[0120] In some example embodiments, the apparatus further comprises means for performing other steps in some embodiments of method 500. In some embodiments, the means comprises at least one processor and at least one memory comprising computer program code. The at least one memory and the computer program code are configured to cause execution of the apparatus together with the at least one processor.

[0121] Figure 6 600 is a simplified block diagram of a device suitable for implementing some example embodiments of the present disclosure. The device 600 may be provided to implement a communication device, such as Figure 1 The terminal device 110 or the network device 120 is shown. As shown in the figure, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

[0122] The communication module 640 is used for two-way communication. The communication module 640 has at least one antenna to facilitate communication. The communication interface may represent any interface necessary to communicate with other network elements.

[0123] As non-limiting examples, processor 610 may be of any type suitable for a local technology network, and may include one or more of the following: 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. Device 600 may have multiple processors, such as application specific integrated circuit chips that are time slaved to a clock of a synchronized main processor.

[0124] The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 624, electrically programmable read-only memory (EPROM), flash memory, hard disk, compact disk (CD), digital video disk (DVD), and other magnetic storage and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 622 and other volatile memories that will not last for the duration of a power outage.

[0125] Computer program 630 includes computer executable instructions that are executed by associated processor 610. Program 630 may be stored in ROM 624. Processor 610 may perform any suitable actions and processes by loading program 630 into RAM 622.

[0126] The embodiments of the present disclosure can be implemented by means of program 630, so that the device 600 can execute the following steps: Figures 2 to 5 Any process of the present disclosure discussed. The embodiments of the present invention may also be implemented by hardware, or by a combination of software and hardware.

[0127] In some example embodiments, the program 630 may be tangibly embodied in a computer-readable medium that may be included in the device 600 (such as in the memory 620) or in other storage devices accessible to the device 600. The device 600 may load the program 630 from the computer-readable medium to the RAM 622 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc.

[0128] Figure 7 630 is stored on the computer readable medium 700. Note that although Figure 7 Computer readable medium 700 is depicted in the form of a CD or DVD, but computer readable medium 700 may be in any other form suitable for carrying or retaining program 630.

[0129] Generally, various embodiments of the present disclosure may be implemented in hardware or dedicated 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. Although various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flow charts, or using some other graphical representations, it should be understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general hardware or controllers or other computing devices, or some combination thereof.

[0130] 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 instructions included in a program module executed in a device on a target real or virtual processor to perform the above referenced Figure 4-Figure 5 In some embodiments, the program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functions of the program modules can be combined or split between program modules as needed. Machine executable instructions for program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in both local and remote storage media.

[0131] The program code for executing the method of the present disclosure can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device so that the program code enables the functions / operations specified in the flow chart and / or block diagram to be implemented when the program code is executed by the processor or controller. The program code can be executed entirely on the machine, partially on the machine, as an independent software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0132] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of carriers include signals, computer readable media, etc.

[0133] 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, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. More specific examples of computer-readable storage media will include an electrical connection with one or more wires, a portable computer disk, 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 disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. As used herein, the term "non-transient" is a limitation of the medium itself (i.e., tangible, not a signal), not a limitation on data storage persistence (e.g., RAM versus ROM).

[0134] In addition, although the operations are depicted in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown or in sequence, or performing all the operations shown to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be interpreted as limitations on the scope of the present disclosure, but should be interpreted as descriptions of features that may be specific to a particular embodiment. Certain features described in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable sub-combination.

[0135] Although the disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the disclosure defined in 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.

Claims

1. A terminal device, comprising: at least one processor; as well as at least one memory storing instructions, which, when executed by the at least one processor, cause the terminal device to at least: receiving a message from a network device, the message including at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process; as well as A request message is sent to the network device, where the request message includes the first identifier or the second identifier.

2. The terminal device according to claim 1, wherein the terminal device is caused to send the request message by: Based on receiving a paging message including the second identifier from the network device, the request message including the second identifier is sent to the network device.

3. The terminal device according to claim 2, wherein the terminal device is further configured to: Before sending the request message including the second identifier, the SDT process is initiated on at least one random access channel RACH resource not configured for SDT.

4. The terminal device according to claim 3, wherein the terminal device is caused to initiate the SDT process by: Based on determining that no uplink SDT data exists in the buffer, the SDT process is initiated on the at least one RACH resource not configured for SDT.

5. The terminal device according to claim 2, wherein the terminal device is further configured to: Before sending the request message including the second identifier, the SDT process is initiated on at least one RACH resource configured for SDT based on determining that uplink SDT data exists in a buffer.

6. The terminal device according to claim 4 or 5, wherein the terminal device is configured to initiate the SDT process by: The SDT process is further initiated based on a reference signal received power (RSRP) of the communication link being higher than an RSRP threshold.

7. The terminal device according to claim 4 or 5, wherein the terminal device is configured to initiate the SDT process by: The SDT process is further initiated based on the RSRP of the communication link being lower than an RSRP threshold.

8. The terminal device according to claim 1, wherein the terminal device is further configured to: receiving a paging message including the second identifier from the network device; and Before sending the request message, the non-SDT process is initiated on at least one RACH resource not configured for SDT based on determining that there is no uplink SDT data in the buffer and the RSRP of the communication link is lower than the RSRP threshold or there is uplink non-SDT data in the buffer.

9. The terminal device according to claim 8, wherein the terminal device is further caused to send the request message by: The request message including the first identifier is sent to the network device.

10. The terminal device according to claim 9, wherein the terminal device is further configured to: Based on determining that there is no uplink data in the buffer and the RSRP of the communication link is below an RSRP threshold, the cause in the request message is set to a first cause value, and the first cause value indicates that the non-SDT process is for mobile terminated (MT) access.

11. The terminal device according to claim 9, wherein the terminal device is further configured to: Based on determining that there is uplink non-SDT data in the buffer, a cause in the request message is set to a second cause value, and the second cause value indicates that the non-SDT procedure is for mobile originated (MO) access.

12. The terminal device according to claim 1, wherein the terminal device is further configured to: receiving, from the network device, a paging message including the first identifier; Initiating the non-SDT procedure on at least one RACH resource not configured for SDT, and The terminal device is configured to send the request message by: The request message including the first identifier is sent to the network device.

13. The terminal device according to claim 1, wherein the terminal device is further configured to: Before sending the request message, based on determining that there is uplink SDT data in the buffer and the RSRP of the communication link is above the RSRP threshold, initiating the SDT process on at least one RACH resource not configured for SDT, the SDT process being a mobile originated (MO)-SDT process, and The terminal device is configured to send the request message by: The request message including the second identifier is sent to the network device.

14. The terminal device according to any one of claims 6 to 11 and 13, wherein the RSRP threshold for MT-SDT is different from the RSRP threshold for MO-SDT.

15. The terminal device according to any one of claims 1 to 14, wherein the first identifier and the second identifier are a completely inactive radio network temporary identifier (I-RNTI) or a short I-RNTI used for an SDT procedure.

16. The terminal device according to any one of claims 1 to 15, wherein the message is a release message or a reconfiguration message.

17. A network device comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the network device to at least: Sending a message to a terminal device, the message including at least a first identifier of the terminal device for a non-small data transmission (non-SDT) process and a second identifier of the terminal device for an SDT process; as well as A request message is received from the terminal device, where the request message includes the first identifier or the second identifier.

18. The network device of claim 17, wherein the network device is further configured to: Before receiving the request message, a paging message including the second identifier is sent to the terminal device.

19. The network device of claim 18, wherein the network device is further configured to: After sending the paging message including the second identifier, it is determined that the SDT process is initiated on at least one random access channel (RACH) resource not configured for SDT.

20. The network device of claim 18, wherein the network device is further caused to: after sending the paging message including the second identifier, determining, based on determining that the non-SDT process is initiated on at least one RACH resource not configured for SDT and the received request message includes the first identifier, that a reference signal received power (RSRP) of the communication link at the terminal device is below an RSRP threshold or that there is uplink non-SDT data to be sent at the terminal device; and The terminal device is configured to enter a connected state.

21. The network device of claim 20, wherein the network device is caused to determine that there is uplink non-SDT data to be sent at the terminal device by: Based on determining that the cause in the request message is set to a second cause value, which indicates that the non-SDT procedure is for mobile originated (MO) access, it is determined that there is uplink non-SDT data to be sent at the terminal device.

22. The network device according to claim 20 or 21, wherein the RSRP threshold for MT-SDT is different from the RSRP threshold for MO-SDT.

23. The network device of claim 18, wherein the network device is further caused to: after sending the paging message including the second identifier, determining that the non-SDT procedure is initiated on at least one RACH resource not configured for SDT, and the received request message includes the first identifier; determining that a cause in the request message is set to a first cause value, the first cause value indicating that the non-SDT procedure is for mobile terminated (MT) access; as well as SDT data is sent to the terminal device without configuring the terminal device to enter a connected state.

24. The network device of claim 18, wherein the network device is further caused to: after sending the paging message including the second identifier, determining that there is no uplink SDT data to be sent at the terminal device based on determining that the SDT procedure is initiated on at least one RACH resource not configured for SDT and the received request message includes the second identifier; SDT data is sent to the terminal device without configuring the terminal device to be in a connected state.

25. The network device of claim 18, wherein the network device is further caused to: After sending the paging message including the second identifier, based on determining that the SDT process is initiated on at least one RACH resource configured for SDT and the received request message includes the second identifier, it is determined that there is uplink SDT data to be sent at the terminal device and that the terminal device has received the paging message including the second identifier.

26. The network device of claim 17, wherein the network device is further caused to: Before receiving the request message, sending a paging message including the first identifier to the terminal device; and After sending the paging message including the first identifier, it is determined that the non-SDT procedure is initiated on at least one RACH resource not configured for SDT.

27. The network device of claim 17, wherein the network device is further caused to: Before receiving the request message including the second identifier, it is determined that the SDT process is initiated on at least one RACH resource not configured for SDT, the SDT process being a mobile originated (MO)-SDT process.

28. The network device according to any one of claims 17 to 27, wherein the first identifier and the second identifier are a completely inactive radio network temporary identifier (I-RNTI) or a short I-RNTI for an SDT procedure.

29. The network device according to any one of claims 17 to 28, wherein the message is a release message or a reconfiguration message.

30. A method comprising: At a terminal device, receiving a message from a network device, the message including at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process; as well as A request message is sent to the network device, where the request message includes the first identifier or the second identifier.

31. A method comprising: At a network device, sending a message to a terminal device, the message including at least a first identifier of the terminal device for a non-small data transfer (non-SDT) process and a second identifier of the terminal device for an SDT process; as well as A request message is received from the terminal device, where the request message includes the first identifier or the second identifier.

32. An apparatus comprising: means for receiving, at a terminal device, a message from a network device, the message comprising at least a first identifier of the terminal device for a non-small data transfer (non-SDT) procedure and a second identifier of the terminal device for an SDT procedure; as well as means for sending a request message to the network device, the request message comprising the first identifier or the second identifier.

33. An apparatus comprising: means for sending, at a network device, a message to a terminal device, the message comprising at least a first identifier of the terminal device for a non-small data transfer (non-SDT) procedure and a second identifier of the terminal device for an SDT procedure; as well as means for receiving a request message from the terminal device, the request message comprising the first identifier or the second identifier.

34. A non-transitory computer readable medium comprising program instructions for causing an apparatus to at least perform the method according to claim 30 or 31.

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