First network device, terminal device, and method performed thereby

Abstract

The embodiments of the present disclosure relate to a method, an apparatus, and a computer-readable medium for communication. A first network device receives a first paging message including information about a MT-SDT for a terminal device from a second network device in a RAN, and determines whether to perform the MT-SDT for the terminal device based on the information. If performing the MT-SDT for the terminal device, the first network device transmits a second paging message to the terminal device including an instruction to perform the MT-SDT for the terminal device. Thus, a MT-SDT procedure can be triggered.

Description

[Technical Field]

[0001] FIELD Embodiments of the present disclosure relate generally to the field of telecommunications, and more particularly to communication methods, apparatus, and computer storage media for small data transmission (SDT). [Background technology]

[0002] Typically, a terminal device in an inactive state may still have small and infrequent data traffic to transmit. Until 3rd Generation Partnership Project (3GPP) Release 16, the inactive state did not support data transmission, and the terminal device had to resume the connection (i.e., enter the connected state) for both downlink and uplink data. This causes unnecessary power consumption and signaling overhead.

[0003] In this case, 3GPP Release 17 has approved Small Data Transmission (SDT) in inactive state. SDT is a procedure that allows data transmission while remaining in inactive state (i.e., without transitioning to connected state), thus reducing signaling overhead. 3GPP Release 17 specifies only mobile originated SDT (MO-SDT). MO-SDT means that SDT in inactive state is triggered by the arrival of uplink (UL) data. One of the possible extension aspects in 3GPP Release 18 is mobile terminated SDT (MT-SDT). MT-SDT means that SDT in inactive state is triggered by the arrival of downlink (DL) data. For now, MT-SDT-related technologies are still immature and require further development. Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, embodiments of the present disclosure provide a communication method, apparatus, and computer storage medium. [Means for solving the problem]

[0005] In a first aspect, a method of communication is provided, the method including: receiving, in a first network device, a first paging message from a second network device in a radio access network, the first paging message including information related to a MT-SDT for a terminal device; determining, based on the information, whether to perform the MT-SDT for the terminal device; and, according to the determination to perform the MT-SDT for the terminal device, sending, to the terminal device, a second paging message including a first instruction indicating to perform the MT-SDT for the terminal device.

[0006] In a second aspect, a method of communication is provided, the method including: transmitting, at a second network device in a radio access network, a first paging message to a first network device, the first paging message including information related to a MT-SDT for a terminal device.

[0007] In a third aspect, a method of communication is provided, the method including: receiving, at a terminal device, a radio resource control (RRC) release message from a network device, the message including configuration of a first set of radio bearers supporting MT-SDT; storing the configuration; and entering an inactive state.

[0008] In a fourth aspect, a method of communication is provided, the method including: transmitting, at a network device, an RRC release message to a terminal device, the RRC release message including configuration of a first set of radio bearers supporting MT-SDT.

[0009] In a fifth aspect, there is provided a method of communications, the method including receiving, at a network device, an indication from a terminal device indicating arrival of uplink data from a second set of radio bearers that support MO-SDT and that are suspended.

[0010] In a sixth aspect, a terminal device is provided, the terminal device comprising: a processor; and a memory coupled to the processor, the memory storing instructions that, when executed by the processor, cause the terminal device to perform the method according to the third aspect of the present disclosure.

[0011] In a seventh aspect, there is provided a network device comprising: a processor; and a memory coupled to the processor, the memory storing instructions that, when executed by the processor, cause the network device to perform a method according to the first, second, fourth or fifth aspect of the present disclosure.

[0012] In an eighth aspect, there is provided a computer-readable medium storing instructions that, when executed on at least one processor, cause the at least one processor to perform a method according to the third aspect of the present disclosure.

[0013] In a ninth aspect, there is provided a computer-readable 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 the first, second, fourth, or fifth aspect of the present disclosure.

[0014] Other features of the present disclosure will become readily apparent from the following description. [Brief explanation of the drawings]

[0015] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description of several embodiments of the present disclosure in the accompanying drawings.

[0016] [Figure 1A] FIG. 1 illustrates an exemplary communication network in which some embodiments of the present disclosure may be implemented.

[0017] [Figure 1B] FIG. 1 is a schematic diagram illustrating a user plane (UP) protocol stack in which some embodiments of the present disclosure may be implemented.

[0018] [Figure 1C] FIG. 1 is a schematic diagram illustrating a control plane (CP) protocol stack in which some embodiments of the present disclosure may be implemented.

[0019] [Figure 2A] FIG. 1 is a schematic diagram illustrating a radio access network (RAN) paging procedure in which some embodiments of the present disclosure may be implemented.

[0020] [Figure 2B] FIG. 1 is a schematic diagram illustrating a one-time MO-SDT procedure in which some embodiments of the present disclosure can be implemented.

[0021] [Figure 2C] FIG. 1 is a schematic diagram illustrating an MO-SDT procedure including an initial transmission and subsequent transmissions, in which some embodiments of the present disclosure can be implemented.

[0022] [Figure 3] FIG. 1 is a schematic diagram illustrating a process for communication during an MT-SDT procedure, according to an embodiment of the present disclosure.

[0023] [Figure 4] FIG. 10 is a schematic diagram illustrating another process for communication during an MT-SDT procedure, according to an embodiment of the present disclosure.

[0024] [Figure 5A]FIG. 10 is a schematic diagram illustrating another process for communication during an MT-SDT procedure, according to an embodiment of the present disclosure.

[0025] [Figure 5B] FIG. 10 is a schematic diagram illustrating another process for communication during an MT-SDT procedure, according to an embodiment of the present disclosure.

[0026] [Figure 6] FIG. 1 illustrates an exemplary communication method implemented in a network device serving a terminal device, according to some embodiments of the present disclosure.

[0027] [Figure 7] FIG. 1 illustrates an exemplary communication method implemented in a network device as a final serving network device for a terminal device, in accordance with some embodiments of the present disclosure.

[0028] [Figure 8] FIG. 1 illustrates an exemplary communication method implemented in a terminal device, according to some embodiments of the present disclosure.

[0029] [Figure 9] FIG. 1 illustrates an exemplary communication method implemented in a network device as a final serving network device for a terminal device, in accordance with some embodiments of the present disclosure.

[0030] [Figure 10] FIG. 10 illustrates another exemplary communication method implemented in a network device serving a terminal device, according to some embodiments of the present disclosure.

[0031] [Figure 11] FIG. 1 is a schematic block diagram of an apparatus suitable for implementing embodiments of the present disclosure.

[0032] In the drawings, the same or similar reference numbers represent the same or similar elements. DETAILED DESCRIPTION OF THE INVENTION

[0033] The principles of the present disclosure will now be described with reference to some embodiments. It should be understood that these embodiments are provided for illustrative purposes only to assist those skilled in the art in understanding and practicing the present disclosure, and do not imply any limitation on the scope of the present disclosure. The disclosure described herein can be implemented in various ways different from those described below.

[0034] 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 pertains.

[0035] 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, desktop computers, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, tablets, wearable devices, Internet of Things (IoT) devices, any Internet of Things (IoE) devices, machine-type communication (MTC) devices, and in-vehicle devices for V2X communications. Here, the "X" in V2X represents pedestrians, vehicles, or infrastructure / networks, 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. The term "terminal device" may be used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device. Additionally, the term "network device" refers to a device capable of providing or hosting a cell or coverage area through which terminal devices can communicate. Examples of network devices include, but are not limited to, low power nodes such as a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a next generation Node B (gNB), a transmit / receive point (TRP), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a femto node, and a pico node.

[0036] In one embodiment, a terminal device can connect to a first network device and a second network device. One of the first network device and the second network device may be a master node and the other a secondary node. The first network device and the second network device may use different radio access technologies (RATs). In one embodiment, the first network device may be a first RAT device, and the second network device may be a second RAT device. In one embodiment, the first RAT device is an eNB, and the second RAT device is a gNB. Information related to the different RATs may be transmitted to the terminal device from at least one of the first network device or the second network device. In one embodiment, the first information may be transmitted from the first network device to the terminal device, and the second information may be transmitted from the second network device directly or via the first network device to the terminal device. In one embodiment, information related to the terminal device configuration configured by the second network device may be transmitted from the second network device via the first network device. The information regarding the reconfiguration of the terminal device configured by the second network device may be transmitted to the terminal device directly from the second network device or via the first network device.

[0037] As used herein, the singular forms "a" and "the" include the plural forms unless the context clearly indicates otherwise. The term "comprises" and variations thereof should be understood as open-ended terms meaning "including, but not limited to." The term "based on" should be understood as "based at least in part on." The terms "one embodiment" and "embodiment" should be understood as "at least one embodiment." The term "another embodiment" should be understood as "at least one other embodiment." Terms such as "first," "second," etc. may refer to different or the same object. The following may include other explicit and implicit definitions.

[0038] In some instances, values, procedures, or devices are referred to as "best," "lowest," "highest," "minimum," "maximum," etc. It should be understood that such descriptions are intended to illustrate that choices may be made from among many functional alternatives used, and that such choices are not necessarily better, smaller, higher, or otherwise more preferred than other choices.

[0039] Traditionally, there are various applications that exchange data in small amounts and infrequently. For example, in some applications for mobile devices, SDT may include traffic from instant messaging (IM) services, such as heartbeat or keep-alive traffic from IM or email clients and other services, push notifications in various applications, traffic from wearable devices (including, for example, periodic location information), etc. In some applications for non-mobile devices, SDT may include sensor data (e.g., temperature, pressure measurements transmitted periodically or in an event-triggered manner within an IoT network), measurement and alarm information sent from smart meters, etc.

[0040] As mentioned above, MT-SDT-related technologies are still in their infancy and require further development. For example, in a multi-gNB scenario, it is important to decide which gNB should trigger MT-SDT. Another example is which radio bearer or bearers should support MT-SDT.

[0041] In view of this, embodiments of the present disclosure provide a communication solution for MT-SDT to overcome the above and other potential problems. The principles and embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Example of communication environment

[0042] FIG. 1A is a schematic diagram illustrating an exemplary communication network 100 in which embodiments of the present disclosure can be implemented. As shown in FIG. 1A, communication network 100 may include a terminal device 110 and multiple network devices. For illustrative purposes, a first network device 120 and a second network device 130 are shown as multiple network devices. First network device 120 and second network device 130 provide respective cells 121 and 131 to serve the terminal device. In the example of FIG. 1A, terminal device 110 is within cell 121 of first network device 120, and terminal device 110 may communicate with first network device 120. Cell 121 may be referred to as a serving cell of terminal device 110.

[0043] In the context of this application, it is assumed that the second network device 130 is the last serving network device for the terminal device 110. In other words, the second network device 130 instructs the terminal device 110 to enter an inactive state. The last serving network device maintains the context of the terminal device 110 and an NG connection with the serving authentication management function (AMF) and user plane function (UPF) in a core network (CN) (not shown). The first network device 120 is a neighboring network device of the second network device 130, and the cell 121 of the first network device 120 is included in the RAN-based notification area (RNA) of the terminal device 110. The RNA of the terminal device 110 is configured by the last serving network device, i.e., the second network device 130. The RNA may cover a single cell or multiple cells and may be included in a CN registration area, and Xn connectivity can be utilized within the RNA. The terminal device 110 may move within the RNA without notifying the network.

[0044] 1A is provided for illustrative purposes and should not be understood as implying any limitations on the present disclosure. Communication network 100 may include any suitable number of network devices and / or terminal devices suitable for implementing embodiments of the present disclosure. Furthermore, each of first network device 120 and second network device 130 may provide more cells to terminal device 110.

[0045] 1A, terminal device 110 may communicate with first network device 120 and second network device 130 via channels, such as wireless communication channels. Communications in communication network 100 may conform to any suitable standard, including, but not limited to, Global System for Mobile Communications (GSM), Long Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE Radio Access Network (GERAN), Machine Type Communication (MTC), etc. Furthermore, communications may be performed according to any generation of communication protocols now known or developed in the future. Examples of communication protocols include, but are not limited to, first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, and fifth generation (5G) communication protocols.

[0046] Communication in the direction from the terminal device 110 to the first network device 120 or the second network device 130 is referred to as UL communication, and communication in the direction from the first network device 120 or the second network device 130 to the terminal device 110 is referred to as DL communication. The terminal device 110 may travel between cells of the first network device 120 or the second network device 130, and possibly other network devices. In UL communication, the terminal device 110 may transmit UL data and control information to the first network device 120 or the second network device 130 over an UL channel. In DL communication, the first network device 120 or the second network device 130 may transmit DL data and control information to the terminal device 110 over a DL channel.

[0047] Communications in the communication network 100 may occur according to UP and CP protocol stacks. Generally speaking, for a communication device (e.g., a terminal device or a network device), there may be multiple entities at multiple network protocol layers in the protocol stack, and these entities may be configured to perform corresponding processes on data or signaling sent from and received by the communication device. Figure 1B is a schematic diagram 100B illustrating network protocol layer entities that may be established for a UP protocol stack in a device according to some embodiments of the present disclosure.

[0048] 1B , in the UP, each of the terminal device 110, the first network device 120, and the second network device 130 may include an L1 layer entity, i.e., a physical (PHY) layer entity (also referred to as a PHY entity), and one or more entities of upper layers (L2 layer and L3 layer, i.e., upper layers), including a medium access control (MAC) layer entity (also referred to as a MAC entity), a radio link control (RLC) layer entity (also referred to as an RLC entity), a packet data convergence protocol (PDCP) layer entity (also referred to as a PDCP entity), and a service data application protocol (SDAP) layer entity (also referred to as an SDAP entity, which will be established in 5G and subsequent generation networks). In some cases, the PHY, MAC, RLC, PDCP, and SDAP entities have a stack structure.

[0049] FIG. 1C is a schematic diagram 100C illustrating network protocol layer entities that may be established for a CP protocol stack in an apparatus according to some embodiments of the present disclosure. As shown in FIG. 1C, in a CP, each of the terminal device 110, the first network device 120, and the second network device 130 may include one or more entities of higher layers (L2 and L3 layers), including an L1 layer entity, i.e., a PHY layer entity (also referred to as a PHY entity), a MAC layer entity (also referred to as a MAC entity), an RLC layer entity (also referred to as an RLC entity), a PDCP layer entity (also referred to as a PDCP entity), and a radio resource control (RRC) layer entity (also referred to as an RRC entity). The RRC layer may also be referred to as an access stratum (AS) layer, and therefore, the RRC entity may also be referred to as an AS entity. As shown in FIG. 1C, the terminal device 110 may also include a non-access stratum (NAS) layer entity (also referred to as a NAS entity). The NAS layer on the network side is located in a core network (CN, not shown) rather than in a network device. In some cases, these entities are organized in a stack.

[0050] Generally, communication channels are divided into logical channels, transmission channels, and physical channels. Physical channels are channels through which the PHY layer actually transmits information. For example, physical channels may include a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), a physical random-access channel (PRACH), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH), and a physical broadcast channel (PBCH).

[0051] The transmission channels are channels between the PHY layer and the MAC layer, and may include, for example, a broadcast channel (BCH), a downlink shared channel (DL-SCH), a paging channel (PCH), an uplink shared channel (UL-SCH), and a random access channel (RACH).

[0052] Logical channels are channels between the MAC layer and the RLC layer, and may include, for example, a dedicated control channel (DCCH), a common control channel (CCCH), a paging control channel (PCCH), a broadcast control channel (BCCH), and a dedicated traffic channel (DTCH).

[0053] Generally, a channel between the RRC layer and the PDCP layer is referred to as a radio bearer. The terminal device 110 may be configured to have at least one data radio bearer (DRB) for carrying data plane data and at least one signaling radio bearer (SRB) for carrying control plane data. In the context of the present disclosure, a DRB may be configured to support transmission in an inactive state (i.e., to support SDT). Of course, a DRB may be configured not to support transmission in an inactive state. An SRB may be configured to support transmission in an inactive state. Of course, an SRB may be configured not to support transmission in an inactive state.

[0054] In the RRC layer, three types of SRBs are defined: SRB0, SRB1, and SRB2. SRB0 uses CCCH to establish or re-establish an RRC connection. SRB1 uses DCCH and is established when an RRC connection is established. SRB2 uses DCCH and is established during RRC re-configuration and after the first security activation.

[0055] Additionally, a protocol data unit (PDU) session may be established in the NAS layer of the terminal device 110 to transmit data to and receive data from the CN. A PDU session may correspond to an SDAP entity and may include multiple Quality of Service (QoS) flows. In the context of the present disclosure, a QoS flow may be configured to support transmission in an inactive state. Of course, a QoS flow may also be configured not to support transmission in an inactive state.

[0056] In some scenarios, when the terminal device 110 is in an inactive state, if the second network device 130, as the last serving network device, receives DL data from the UPF or DL ​​signaling associated with the terminal device 110 from the AMF (excluding a UE context release command message), the second network device 130 may page within a cell corresponding to a RAN-based notification area (RNA). This procedure may be referred to as RAN paging. During RAN paging, if the RNA includes cells of one or more neighboring network devices, the second network device 130 may send an XnAP RAN paging message to the one or more neighboring network devices.

[0057] 2A is a schematic diagram illustrating a RAN paging procedure 200A in which some embodiments of the present disclosure can be implemented. For illustrative purposes, the process 200A will be described with reference to FIG. 1. The process 200A may involve a terminal device 110, a first network device 120, and a second network device 130, as shown in FIG. 1.

[0058] 2, the terminal device 110 is in an inactive state. The second network device 130 may determine whether a RAN paging trigger event has occurred (201). For example, if the second network device 130 receives DL data from the UPF or DL ​​signaling associated with the terminal device 110 from the AMF (excluding a UE context release command message), the second network device 130 may determine that a RAN paging trigger event has occurred. Of course, the RAN paging trigger event is not limited to this example and may take any other suitable form.

[0059] If it is determined that a RAN paging trigger event has occurred, the second network device 130 may page in the cell corresponding to the RNA. For convenience, it is determined that the first network device 120 is in the cell corresponding to the RNA, and the following description will be given taking the first network device 120 as an example. In this case, the second network device 130 may send an XnAP RAN paging message to the first network device 120 and other network devices in the RNA (202).

[0060] Upon receiving the XnAP RAN paging message, the first network device 120 may transmit 203 a paging message to the terminal device 110. In some embodiments, the paging message may include an inactive radio network temporary identifier (I-RNTI). Of course, the paging message may also include any other suitable information. If the paging message successfully reaches the terminal device 110, the terminal device 110 may attempt to resume 204 from an inactive state. Thus, the RAN paging procedure is completed. It should be understood that the RAN paging procedure 200A may include more or fewer steps and is not limited to the above example.

[0061] In some scenarios, when a terminal device 110 in an inactive state has a small amount of infrequent data traffic to transmit, the terminal device 110 may initiate an SDT procedure, i.e., MO-SDT. As described above, SDT is a procedure that allows data transmission while remaining in an inactive state (i.e., without transitioning to a connected state). In some embodiments, SDT is enabled on a radio bearer basis and is initiated by the terminal device only after waiting for less than a configured amount of UL data to be transmitted across all SDT-enabled radio bearers and when the measured reference signal received power (RSRP) in the cell exceeds a configured threshold.

[0062] 2B is a schematic diagram illustrating a one-time MO-SDT procedure 200B in which some embodiments of the present disclosure can be implemented. For illustrative purposes, the process 200B will be described with reference to FIG. 1. The process 200B may involve the terminal device 110 and the first network device 120 as shown in FIG. 1. It should be understood that this is merely an example, and that the process 200B may also be performed between the terminal device 110 and the second network device 130.

[0063] As shown in FIG. 2B , the terminal device 110 in the inactive state may transmit an RRC resumption request to the network device 120 together with UL data associated with data traffic (211). For example, the terminal device 110 may transmit the RRC resumption request together with the UL data in Msg A of the two-step RACH procedure or Msg 3 of the four-step RACH procedure. Of course, the terminal device 110 may also transmit the RRC resumption request together with the UL data in configured grant (CG) resources. Upon receiving the RRC resumption request and the UL data, the first network device 120 may transmit an RRC release message to the terminal device 110 together with DL data corresponding to the UL data (212). For example, the first network device 120 may transmit the RRC release message together with the DL data in Msg B of the two-step RACH procedure or Msg 4 of the four-step RACH procedure. The first network device 120 may also transmit the RRC release message together with the DL data in response to the transmission on the CG resources. At this point, the SDT procedure 200B ends.

[0064] FIG. 2C is a schematic diagram illustrating an MO-SDT procedure 200C including an initial transmission and subsequent transmissions, in which some embodiments of the present disclosure can be implemented. As shown in FIG. 2C, a terminal device 110 in an inactive state may transmit an RRC resume request together with UL data and a BSR to a first network device 120 (221). For example, the terminal device 110 may transmit the RRC resume request together with the UL data and a BSR in Msg A of a two-step RACH procedure or Msg 3 of a four-step RACH procedure. Of course, the terminal device 110 may also transmit the RRC resume request together with the UL data in configured grant (CG) resources. The RRC resume request may include a resume cause. Upon receiving the RRC resume request together with the UL data and a BSR, the first network device 120 may transmit an indication of a subsequent transmission to the terminal device 110 (222). For example, the first network device 120 may transmit an explicit RRC message indicating a subsequent transmission. As another example, the first network device 120 may implicitly indicate a subsequent transmission by sending an UL grant for another transmission. In some embodiments, the first network device 120 may send DL data with an indication to the terminal device 110. At this point, the initial transmission is complete.

[0065] Based on this indication, terminal device 110 may transmit another UL data and a BSR to first network device 120 (223), for example, based on a dynamic or configured grant. First network device 120 may then transmit a UL grant for the dynamic grant to terminal device 110 (224). In some embodiments, first network device 120 may transmit DL data along with the UL grant to terminal device 110. Based on the UL grant from first network device 120, terminal device 110 may transmit remaining UL data to first network device 120 (225). Accordingly, first network device 120 may transmit an RRC release message to terminal device 110 (226). At this point, the subsequent transmission is complete; that is, SDT procedure 200C ends. It should be understood that SDT procedure 200C may include more or fewer steps in the subsequent transmission. MT-SDT implementation example

[0066] The embodiments of the present disclosure provide communication solutions for MT-SDT. In one aspect, a solution for triggering MT-SDT is provided. In another aspect, a solution for setting up a radio bearer for MT-SDT is provided. In yet another aspect, a solution for processing MO-SDT during MT-SDT is provided. This will be described in detail below with reference to embodiments 1 to 3. Embodiment 1

[0067] In this embodiment, a solution for triggering MT-SDT is provided. In some embodiments, the triggering of MT-SDT may be performed by the last serving network device for the terminal device. In some embodiments, the triggering of MT-SDT may be performed by a neighboring network device of the last serving network device for the terminal device. In other words, the triggering of MT-SDT may be performed by any network device within the RNA of the terminal device. This solution will be described in detail with reference to Figure 3.

[0068] 3 is a schematic diagram illustrating a process 300 for communication during an MT-SDT procedure according to an embodiment of the present disclosure. For illustrative purposes, the process 300 will be described with reference to FIG. 1. The process 300 may involve a terminal device 110, a first network device 120, and a second network device 130, as shown in FIG. 1. Assume that the first network device 120 is the current serving network device for the terminal device 110, the second network device 130 is the last serving network device for the terminal device 110, and the terminal device 110 has already entered an inactive state under the direction of the last serving network device.

[0069] 3, when the second network device 130 determines that a RAN paging trigger event has occurred, the second network device 130 may send a RAN paging message (for convenience, also referred to herein as a first paging message) to the first network device 120 and other network devices (not shown) in the cell corresponding to the RNA. According to an embodiment of the present disclosure, the RAN paging message includes information regarding the MT-SDT for the terminal device 110. In this way, triggering of the MT-SDT can be realized.

[0070] In some embodiments, second network device 130 may determine whether to perform MT-SDT for terminal device 110. In some embodiments, second network device 130 may determine whether to perform MT-SDT for terminal device 110 based on at least one of a radio bearer associated with the DL data, the size of the DL data, or the capabilities of terminal device 110. In some embodiments, second network device 130 may determine whether to perform MT-SDT for terminal device 110 based on at least one of whether terminal device 110 supports MT-SDT, whether the DL data is from a radio bearer configured to have SDT, or whether the size of the DL data is smaller than a threshold size. For example, if terminal device 110 supports MT-SDT, all DL data is from one or more radio bearers configured to have SDT, and the size of the DL data is smaller than a threshold size, second network device 130 may determine to perform MT-SDT for terminal device 110. That is, the second network device 130 may trigger the MT-SDT. It should be understood that this is just one example, and the second network device 130 may adopt any other suitable method to determine whether to perform the MT-SDT for the terminal device 110.

[0071] In some embodiments, once it is determined whether to perform MT-SDT for the terminal device 110, the second network device 130 may generate, as information in a RAN paging message, an instruction (for convenience, also referred to herein as a second instruction) indicating whether to perform MT-SDT for the terminal device 110. In this manner, the triggering of MT-SDT is determined by the last serving network device. Because the last serving network device has all the information necessary for determining MT-SDT, it is efficient and easy for the last serving network device to determine whether to perform MT-SDT.

[0072] In some embodiments, the second network device 120 may cause an information element (IE) indicated by the MT-SDT indication to be included in the RAN paging message, for example, as shown in Table 1 below. TIFF0007750398000001.tif247168

[0073] The type of the IE MT-SDT indication may be ENUMERATED(true,...). It should be understood that Table 1 is only an example and any other suitable form is also possible.

[0074] In some alternative embodiments, second network device 130 may transmit auxiliary information to facilitate first network device 120 in determining whether to trigger MT-SDT. In some embodiments, this information or auxiliary information may include at least one of the following: a size of downlink data, a capability of terminal device 110 for SDT, or a context of terminal device 110 regarding its configuration for SDT. It should be understood that this information may also include any other suitable items, and the present disclosure is not limited in this respect.

[0075] In some embodiments, the second network device 120 may include auxiliary information IEs in the RAN paging message, such as DL data size, UE capability for SDT, and UE configuration for SDT IEs, as shown in Table 2 below. TIFF0007750398000002.tif225168

[0076] The type of the IE representing DL data size may be INTEGER or BIT STRING. The type of the IE representing UE capability for SDT may be OCTET STRING. The type of the IE representing UE configuration for SDT may be OCTET STRING. It should be understood that Table 2 is only an example, and any other suitable form is also possible. In this way, each network device can decide whether to trigger MT-SDT, so its implementation is flexible.

[0077] Upon receiving the RAN paging message, first network device 120 may determine (303) based on this information whether to perform MT-SDT for terminal device 110. In some embodiments where this information includes an indication to perform MT-SDT for terminal device 110, first network device 120 may determine to perform MT-SDT for terminal device 110 according to the determination of second network device 130.

[0078] In some alternative embodiments in which this information includes an indication indicating to execute MT-SDT for terminal device 110, first network device 120 may further determine on its own whether to execute MT-SDT for terminal device 110. For example, first network device 120 may determine whether to execute MT-SDT for terminal device 110 based on whether first network device 110 supports MT-SDT. As another example, first network device 120 may determine whether to execute MT-SDT for terminal device 110 based on whether a load condition for first network device 110 satisfies a threshold condition. Of course, first network device 120 may employ any other suitable method to determine whether to execute MT-SDT for terminal device 110, and the present disclosure is not limited in this respect.

[0079] In some embodiments, where the information includes auxiliary information to facilitate the first network device 120 in determining whether to trigger MT-SDT, the first network device 120 may determine whether to perform MT-SDT for the terminal device 110 based on the auxiliary information. In some embodiments, the first network device 120 may determine whether to perform MT-SDT for the terminal device 110 based on whether the first network device 120 supports MT-SDT. In some embodiments, the first network device 120 may determine whether to perform MT-SDT for the terminal device 110 based on whether the terminal device 110 supports MT-SDT. In some embodiments, the first network device 120 may determine whether to perform MT-SDT for the terminal device 110 based on whether the load condition for the first network device 120 satisfies a threshold condition. In some embodiments, the first network device 120 may determine whether to perform MT-SDT for the terminal device 110 based on whether the size of the DL data is smaller than a threshold size. Of course, the first network device 120 may adopt any other suitable method to determine whether to perform MT-SDT for the terminal device 110, and the present disclosure is not limited in this respect.

[0080] If determining to perform MT-SDT for terminal device 110, first network device 120 may send a paging message (also referred to herein as a second paging message for convenience) to page terminal device 110 (303). The second paging message may include an instruction (also referred to herein as a first instruction for convenience) indicating to perform MT-SDT for terminal device 110.

[0081] In some embodiments, upon determining to perform MT-SDT for terminal device 110, second network device 130 may also send a paging message (also referred to herein as a third paging message for convenience) to page terminal device 110 (304). The third paging message may also include an indication (also referred to herein as a third indication for convenience) indicating to perform MT-SDT for terminal device 110.

[0082] This allows flexible triggering of MT-SDT. Embodiment 2

[0083] In this embodiment, a solution is provided for setting up one or more radio bearers for MT-SDT.

[0084] In the case of MO-SDT, which radio bearers can support SDT may be configured by the network side. Considering that the traffic characteristics of each radio bearer may be different, it may not be appropriate to support the same radio bearer for MO-SDT and MT-SDT. For example, some radio bearers may have large UL packet sizes but small DL packet sizes. As another example, some radio bearers may have large DL packet sizes but small UL packet sizes. In view of this, an embodiment of the present disclosure proposes to configure which radio bearers support MO-SDT and which radio bearers support MT-SDT, respectively. This will be described in detail with reference to FIG. 4.

[0085] 4 is a schematic diagram illustrating another process 400 for communication during an MT-SDT procedure according to an embodiment of the present disclosure. For illustrative purposes, the process 400 will be described with reference to FIG. 1. The process 400 may involve the terminal device 110, the first network device 120, and the second network device 130, as shown in FIG. 1. Assume that the first network device 120 is the current serving network device for the terminal device 110, and the second network device 130 is the last serving network device for the terminal device 110.

[0086] As shown in FIG. 4, the second network device 130 may send an RRC release message to the terminal device 110 to instruct the terminal device 110 to enter the inactive state (410). For example, the second network device 130 may configure which radio bearers support MT-SDT using suspendConfig in the RRC release message. In some embodiments, the RRC release message may include configuration of a set of radio bearers (also referred to herein as a first set of radio bearers for convenience), where the set of radio bearers supports MT-SDT. Thus, the radio bearers supporting MT-SDT are configured. In some embodiments, the first set of radio bearers may be different from the set of radio bearers (also referred to herein as a second set of radio bearers for convenience) that support MO-SDT. In some alternative embodiments, the first set of radio bearers may be the same as the second set of radio bearers. In some alternative embodiments, the set of radio bearers configured to support MO-SDT may also be treated as supporting MT-SDT. In some embodiments, the first set of radio bearers may include an SRB and a DRB. Of course, the first set of radio bearers may take any other suitable form.

[0087] Upon receiving the RRC release message, terminal device 110 may store (420) the configuration of the first set of radio bearers and enter (430) an inactive state.

[0088] Terminal device 110 in an inactive state may receive (440) a paging message from a network device (for convenience, first network device 120 is used as an example, but the last serving network device or any neighboring network device is possible) that includes an instruction to perform MT-SDT for terminal device 110. As a result, terminal device 110 may initiate (450) an RRC resumption procedure for MT-SDT.

[0089] During initiation of the RRC resumption procedure, in some embodiments, terminal device 110 may resume a first set of radio bearers supporting MT-SDT (451). In some embodiments, terminal device 110 may perform PDCP reestablishment for PDCP entities of the first set of radio bearers (452) and RLC reestablishment for RLC entities of the first set of radio bearers (453). In some embodiments, terminal device 110 may send an RRC resumption request message to first network device 120 (454). In some embodiments, the RRC resumption request message may include the resumption reason set as MT-SDT.

[0090] In some embodiments, the terminal device 110 may determine a set of random access resources and a set of random access parameters configured for non-SDT, and initiate an RRC resumption procedure using the set of random access resources and the set of random access parameters. The set of random access resources configured for non-SDT means that the set of random access resources is not reserved exclusively for SDT. The set of random access parameters configured for non-SDT means that the set of random access parameters is not configured exclusively for SDT.

[0091] In some alternative embodiments, terminal device 110 may determine whether buffered UL data exists for one or more radio bearers in the first set of radio bearers. If UL data exists, terminal device 110 may determine a set of random access resources and a set of random access parameters to be configured for SDT. If no buffered UL data exists for the first set of radio bearers, terminal device 110 may determine a set of random access resources and a set of random access parameters to be configured for non-SDT and initiate an RRC resumption procedure using the determined set of random access resources and the determined set of random access parameters.

[0092] In some embodiments, the terminal device may determine the set of random access resources by determining resources for a preamble and a random access occasion. In some embodiments, the set of random access parameters may include rsrp-ThresholdSSB, msgA-RSRP-ThresholdSSB, preambleReceivedTargetPower / gA-PreambleReceivedTargetPower, powerRampingStep / msgA-PreamblePowerRampingStep, msg3-DeltaPreamble / msgA-DeltaPreamble, msg3-DeltaPreamble / msgA-DeltaPreamble, messagePowerOffsetGroupB, etc. It should be noted that any other suitable parameters are also possible.

[0093] In some embodiments, terminal device 110 may send an RRC Resume Request message for MT-SDT without UL data to first network device 120. Upon receiving the RRC Resume Request message, first network device 120 may send an RRC Release message with DL data to terminal device 110 (460). In this manner, the MT-SDT procedure can be performed.

[0094] In some alternative embodiments, upon receiving the RRC resume request message, the first network device 120 may transmit (470) DL data and an UL grant to the terminal device 110. The terminal device 110 may then transmit (480) UL data based on the UL grant. The first network device 120 may then transmit (490) an RRC release message or an RRC resume message to the terminal device 110. In this manner, the MT-SDT procedure may also be performed. Embodiment 3

[0095] In some scenarios, after the terminal device 110 initiates the RRC resumption procedure for MT-SDT, UL data may arrive at the terminal device 110 from a suspended radio bearer that supports MO-SDT. In this embodiment, a solution for processing MO-SDT during MT-SDT is provided for the above scenario, which will be described in detail with reference to Figures 5A and 5B.

[0096] 5A is a schematic diagram illustrating another process 500A for communication during an MT-SDT procedure according to an embodiment of the present disclosure. For illustrative purposes, the process 500A will be described with reference to FIG. 1. The process 500A may involve the terminal device 110 and the network device 110 (for convenience, illustrated as the first network device 120) as shown in FIG. 1. It should be understood that the process 500A may also be performed between the terminal device 110 and the second network device 130 as the final serving network device.

[0097] After initiating the RRC resumption procedure for MT-SDT, terminal device 110 may determine that UL data is arriving from a second set of radio bearers that support MO-SDT and are suspended. In this case, as shown in FIG. 5A, terminal device 110 may send an indication indicating the arrival of UL data to first network device 120 (510). In some embodiments, this indication may include the size of the UL data. Of course, this indication may include any other suitable information. In some embodiments, terminal device 110 may send the indication via an RRC message using SRB1. In some embodiments, terminal device 110 may send the indication via a MAC control element (MAC CE). Of course, any other suitable method for sending this indication is also possible.

[0098] The first network device 120 may transmit an indication (for convenience, also referred to herein as another indication) indicating that UL data has been transmitted by the terminal device 110 in the inactive state (520). For example, the first network device 120 may indicate to the terminal device 110 to transmit UL data in the inactive state by transmitting an RRC message. As another example, the first network device 120 may indicate to the terminal device 110 to transmit UL data in the inactive state by transmitting a MAC CE. Of course, any other suitable method for transmitting the another indication is also possible.

[0099] Upon receiving the further indication, terminal device 110 may resume the second set of radio bearers (530). Terminal device 110 may perform PDCP re-establishment for the PDCP entities of the second set of radio bearers (540) and may perform RLC re-establishment for the RLC entities of the second set of radio bearers (550). Terminal device 110 may then transmit UL data to first network device 120 in the inactive state (560).

[0100] Thus, the MO-SDT is performed during the MT-SDT procedure. In the following, with reference to Figure 5B, another solution for processing the MO-SDT during the MT-SDT is described.

[0101] 5B is a schematic diagram illustrating another process 500B for communication during an MT-SDT procedure according to an embodiment of the present disclosure. For illustrative purposes, the process 500B will be described with reference to FIG. 1. The process 500B may involve the terminal device 110 and the network device 110 (for convenience, illustrated as the first network device 120) as shown in FIG. 1. It should be understood that the process 500A may also be performed between the terminal device 110 and the second network device 130 as the final serving network device.

[0102] After initiating the RRC resumption procedure for MT-SDT, terminal device 110 may determine that UL data is arriving from a second set of radio bearers that support MO-SDT and are suspended. In this case, as shown in FIG. 5B, terminal device 110 may send an indication indicating the arrival of UL data to first network device 120 (570). The sending of the indication in FIG. 5B is similar to the sending described in FIG. 5A, and therefore will not be described again here.

[0103] Upon receiving this indication, first network device 120 may send an RRC resume message to terminal device 110 (580), causing terminal device 110 to enter a connected state. Terminal device 110 may then send UL data to first network device 120 in the connected state (590).

[0104] So far, processing of newly arriving UL data during MT-SDT has been realized. Example of the method

[0105] Therefore, embodiments of the present disclosure provide communication methods implemented in a terminal device and a network device, which will be described below with reference to Figures 6 to 10.

[0106] 6 illustrates an exemplary communication method 600 implemented in a network device serving a terminal device, according to some embodiments of the present disclosure. For example, method 600 may be performed in first network device 120 as shown in FIG. 1. For purposes of explanation, method 600 will be described below with reference to FIG. 1. It should be understood that method 600 may include additional blocks not shown and / or omit some blocks shown, and that the scope of the present disclosure is not limited in this respect.

[0107] In block 610, the first network device 120 receives a first paging message from a second network device 130 in the RAN. The first paging message includes information regarding the MT-SDT for the terminal device 110.

[0108] In some embodiments, this information may include a second indication indicating to perform MT-SDT for terminal device 110. In some embodiments, this information may include auxiliary information to facilitate a decision on whether to perform MT-SDT for terminal device 110. This auxiliary information may include at least one of the following: a downlink data size, a terminal device capability for SDT, or a terminal device context regarding a configuration for SDT. Of course, this information may include any other suitable items.

[0109] In block 620, first network device 120 determines, based on the information, whether to execute MT-SDT for terminal device 110. In some embodiments in which the information includes a second indication indicating to execute MT-SDT for terminal device 110, first network device 120 may determine whether to execute MT-SDT for the terminal device based on at least one of whether first network device 120 supports MT-SDT or whether load conditions for first network device 120 satisfy a threshold condition. It should be understood that any other suitable method for the determination is also possible.

[0110] In some embodiments where this information includes auxiliary information to facilitate a decision on whether to perform MT-SDT for terminal device 110, first network device 120 may determine whether to perform MT-SDT for terminal device 110 based on at least one of whether first network device 120 supports MT-SDT, whether terminal device 110 supports MT-SDT based on at least one of terminal device 110's capabilities for SDT and terminal device 110's context regarding settings for SDT, whether load conditions for first network device 120 meet a threshold condition, or whether the size of the DL data is smaller than a threshold size.

[0111] If, at block 620, it is determined to perform MT-SDT for terminal device 110, the process proceeds to block 630. At block 630, first network device 120 sends a second paging message to terminal device 110. The second paging message includes a first indication to perform MT-SDT for terminal device 110.

[0112] 7 illustrates an exemplary communication method 700 implemented in a network device serving as a final serving network device for a terminal device, according to some embodiments of the present disclosure. For example, method 700 may be performed in second network device 130 as shown in FIG. 1. For purposes of explanation, method 700 will be described below with reference to FIG. 1. It should be understood that method 700 may include additional blocks not shown and / or omit some blocks shown, and that the scope of the present disclosure is not limited in this respect.

[0113] In block 710, the second network device 130 sends a first paging message to the first network device 120 in the RAN. The first paging message includes information about the MT-SDT for the terminal device 110.

[0114] In some embodiments, second network device 130 may determine whether to perform MT-SDT for terminal device 110, and if performing MT-SDT for the terminal device, second network device 130 may send to terminal device 110 a third paging message including a third instruction indicating to perform MT-SDT for terminal device 110. In some embodiments, second network device 130 may determine whether to perform MT-SDT for terminal device 110 based on at least one of whether the terminal device supports MT-SDT, whether the downlink data is from a radio bearer configured to have SDT, or whether the size of the downlink data is smaller than a threshold size.

[0115] In some embodiments, the second network device 130 may generate this information as a second indication indicating whether to perform MT-SDT for the terminal device 110.

[0116] In some embodiments, this information may be generated as auxiliary information to facilitate the decision on whether to perform MT-SDT for terminal device 110. This auxiliary information may include at least one of the following: downlink data size, terminal device capabilities for SDT, or terminal device context regarding configuration for SDT. Of course, this information may also include any other suitable items.

[0117] Thus, the MT-SDT procedure is triggered. The implementation of the method described in Figures 6 and 7 substantially corresponds to the implementation described in connection with Figure 3, so other details will not be repeated here.

[0118] 8 illustrates an exemplary communication method 800 implemented in a terminal device, according to some embodiments of the present disclosure. For example, method 800 may be performed in terminal device 110 as shown in FIG. 1. For purposes of explanation, method 800 will be described below with reference to FIG. 1. It should be understood that method 800 may include additional blocks not shown and / or omit some blocks that are shown, and that the scope of the present disclosure is not limited in this respect.

[0119] In block 810, the terminal device 110 receives an RRC release message from a network device. In some embodiments, the network device may be a last serving network device, such as the second network device 130 shown in Figure 1. The RRC release message includes the configuration of a first set of radio bearers that support MT-SDT.

[0120] In block 820, the terminal device 110 stores the settings. In block 830, the terminal device 110 enters an inactive state.

[0121] In some embodiments, terminal device 110 may further receive a paging message from another network device. The paging message includes a first instruction indicating to perform MT-SDT for terminal device 110. In some embodiments, the other network device may be a last serving network device. In some embodiments, the other network device may be a neighboring network device of the last serving network device. For convenience, the first network device 120 shown in FIG. 1 will be used as an example.

[0122] In response to receiving the paging message from first network device 120, terminal device 110 may initiate an RRC resumption procedure for MT-SDT. In some embodiments, terminal device 110 may resume a first set of radio bearers supporting MT-SDT, perform PDCP reestablishment for PDCP entities of the first set of radio bearers, perform RLC reestablishment for RLC entities of the first set of radio bearers, and send an RRC resumption request message to first network device 120.

[0123] In some embodiments, the terminal device 110 may determine a set of random access resources and a set of random access parameters configured for non-SDT, and initiate an RRC resumption procedure using the set of random access resources and the set of random access parameters.

[0124] In some embodiments, terminal device 110 may determine whether buffered uplink data exists for one or more radio bearers in the first set of radio bearers. If it determines that uplink data exists, terminal device 110 may determine a set of random access resources and a set of random access parameters to be configured for SDT. If it determines that no buffered uplink data exists for the first set of radio bearers, terminal device 110 may determine a set of random access resources and a set of random access parameters to be configured for non-SDT and initiate an RRC resumption procedure using the determined set of random access resources and the determined set of random access parameters.

[0125] In some embodiments, terminal device 110 may determine, after initiation, that uplink data arrives from a second set of radio bearers that support MO-SDT and are suspended, in which case terminal device 110 may send an indication to first network device 120 indicating the arrival of the uplink data.

[0126] In some embodiments, terminal device 110 may further receive another indication from first network device 120 indicating that uplink data has been transmitted by terminal device 110 in the inactive state. Upon receiving the message, terminal device 110 may resume the second set of radio bearers, perform PDCP re-establishment for the PDCP entities of the second set of radio bearers, perform RLC re-establishment for the RLC entities of the second set of radio bearers, and transmit the uplink data to first network device 120 in the inactive state.

[0127] In some alternative embodiments, the terminal device 110 may receive an RRC resume message from the first network device 120. In this case, the terminal device 110 may transmit uplink data to the first network device 120 in a connected state. Thus, an MT-SDT procedure is designed.

[0128] 9 illustrates an exemplary communication method 900 implemented in a network device serving as a final serving network device for a terminal device, according to some embodiments of the present disclosure. For example, method 900 may be performed in second network device 130 as shown in FIG. 1. For purposes of explanation, method 900 will be described below with reference to FIG. 1. It should be understood that method 900 may include additional blocks not shown and / or omit some blocks shown, and that the scope of the present disclosure is not limited in this respect.

[0129] In block 910, the second network device 130 sends an RRC release message to the terminal device 110. The RRC release message includes the configuration of a first set of radio bearers supporting MT-SDT. Thus, one or more radio bearers are configured for MT-SDT.

[0130] 10 illustrates an exemplary communication method 1000 implemented in a network device serving a terminal device, according to some embodiments of the present disclosure. For example, method 1000 may be performed in the first network device 120 or the second network device 130 as shown in FIG. 1. For illustrative purposes, method 1000 will be described below with reference to FIG. 1. For illustrative purposes, the first network device 120 will be used as an example. It should be understood that method 1000 may include additional blocks not shown and / or omit some blocks shown, and that the scope of the present disclosure is not limited in this respect.

[0131] At block 1010, the first network device 120 receives an indication of arrival of uplink data from a second set of radio bearers, the second set of radio bearers supporting MO-SDT and being suspended.

[0132] In some embodiments, first network device 120 may transmit another indication to terminal device 110 indicating that uplink data was transmitted by terminal device 110 in an inactive state. In these embodiments, first network device 120 may receive the uplink data transmitted by terminal device 110 in an inactive state.

[0133] In some embodiments, the first network device 120 may send an RRC resume message to the terminal device 110. In some embodiments, the first network device 120 may receive uplink data transmitted by the terminal device 110 in a connected state.

[0134] Thus, newly arriving UL data during MT-SDT is processed.,The implementation of the method described in Figures 8 to 10 substantially,corresponds to the implementation described in connection with,Figures 4, 5A and 5B, and therefore other details will not be,repeated here. Device implementation example

[0135] 11 is a schematic block diagram of an apparatus 1100 suitable for implementing embodiments of the present disclosure. The apparatus 1100 can be considered as another exemplary implementation of the terminal device 110, the first network device 120, or the second network device 130 shown in FIG. 1. Thus, the apparatus 1100 can be implemented in, or as at least a part of, the terminal device 110, the first network device 120, or the second network device 130.

[0136] As shown, the apparatus 1100 comprises a processor 1110, a memory 1120 coupled to the processor 1110, a suitable transmitter (TX) and receiver (RX) 1140 coupled to the processor 1110, and a communication interface coupled to the TX / RX 1140. The memory 1110 stores at least a portion of a program 1130. The TX / RX 1140 is used for bidirectional communication. The TX / RX 1140 has at least one antenna to facilitate communication, although the access nodes referred to herein may in practice have multiple antennas. The communication interface may represent any interface required for communication with other network elements, such as an X2 / Xn interface for bidirectional communication between eNBs / gNBs, an S1 / NG interface for communication between a Mobility Management Entity (MME) / Access and Mobility Management Function (AMF) / SGW / UPF and an eNB / gNB, an Un interface for communication between an eNB / gNB and a relay node (RN), or a Uu interface for communication between an eNB / gNB and a terminal device.

[0137] The program 1130 is assumed to include program instructions that, when executed by the associated processor 1110, enable the device 1100 to operate according to embodiments of the present disclosure, as described herein with reference to Figures 1-10. The embodiments herein may be implemented by computer software executable by the processor 1110 of the device 1100, by hardware, or by a combination of software and hardware. The processor 1110 may be configured to implement various embodiments of the present disclosure. Furthermore, the combination of the processor 1110 and the memory 1120 may form a processing means 1150 suitable for implementing various embodiments of the present disclosure.

[0138] Memory 1120 may be of any type suitable for a local technology network and may be implemented using any suitable data storage technology, including, 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. While only one memory 1120 is shown in device 1100, several physically distinct memory modules may be present within device 1100. Processor 1110 may be of any type suitable for a local technology 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. Device 1100 may have multiple processors, for example, application-specific integrated circuit chips time-slaved to a clock that synchronizes the main processor.

[0139] In some embodiments, the first network device comprises circuitry configured to receive a first paging message from a second network device in a RAN, the first paging message including information regarding MT-SDT for a terminal device, determine whether to perform the MT-SDT for the terminal device based on the information, and, in accordance with a decision to perform the MT-SDT for the terminal device, send a second paging message to the terminal device, the second paging message including a first instruction indicating to perform the MT-SDT for the terminal device.

[0140] In some embodiments, the information may include a second instruction indicating to perform MT-SDT for the terminal device. In these embodiments, the circuitry may be configured to determine to perform MT-SDT for the terminal device based on the second instruction. In these embodiments, the circuitry may be configured, in response to the instruction indicating to perform the MT-SDT for the terminal device, to determine whether to perform the MT-SDT for the terminal device by determining whether to perform the MT-SDT for the terminal device based on at least one of whether the first network device supports the MT-SDT or whether a load condition for the first network device meets a threshold condition.

[0141] In some embodiments, the information may include at least one of a size of downlink data, a terminal device capability for small data transmission (SDT), or a terminal device context related to a configuration for SDT. In these embodiments, the circuitry may be configured to determine whether to perform the MT-SDT for the terminal device by determining whether to perform the MT-SDT for the terminal device based on at least one of whether the first network device supports the MT-SDT, whether the terminal device supports the MT-SDT based on at least one of the terminal device capability for the SDT and the terminal device context related to the configuration for SDT, whether a load condition for the first network device meets a threshold condition, or whether a size of downlink data is smaller than a threshold size.

[0142] In some embodiments, the second network device comprises circuitry configured to transmit a first paging message to a first network device within a RAN, the first paging message including information regarding an MT-SDT for the terminal device.

[0143] In some embodiments, the circuitry may be further configured to: determine whether to perform the MT-SDT for the terminal device, and, in accordance with a determination to perform the MT-SDT for the terminal device, send a third paging message to the terminal device including a third instruction indicating to perform the MT-SDT for the terminal device. In some embodiments, the circuitry may be configured to determine whether to perform MT-SDT for the terminal device based on at least one of whether the terminal device supports MT-SDT, whether downlink data is from a radio bearer configured to have SDT, or whether a size of the downlink data is smaller than a threshold size.

[0144] In some embodiments, the circuitry may be further configured to generate as the information a second indication indicating whether to perform the MT-SDT for the terminal device.

[0145] In some embodiments, the information may include at least one of a size of downlink data, a capability of the terminal device for SDT, or a context of the terminal device regarding a configuration for SDT.

[0146] In some embodiments, a terminal device comprises circuitry configured to receive an RRC release message from a network device, the RRC release message including configuration of a first set of radio bearers supporting MT-SDT, store the configuration, and enter an inactive state.

[0147] In some embodiments, the circuitry may be further configured to, in response to receiving a paging message from another network device including a first instruction indicating to perform the MT-SDT for the terminal device, initiate an RRC resumption procedure for the MT-SDT, including resuming the first set of radio bearers supporting the MT-SDT, performing PDCP re-establishment for PDCP entities of the first set of radio bearers, performing RLC re-establishment for RLC entities of the first set of radio bearers, and sending an RRC resumption request message to the other network device.

[0148] In some embodiments, the circuitry may be configured to initiate the RRC restart procedure by determining a set of random access resources and a set of random access parameters to be configured for non-small data transmission data, and initiating the RRC restart procedure using the set of random access resources and the set of random access parameters.

[0149] In some embodiments, the circuitry may be configured to initiate the RRC restart procedure for the MT-SDT by determining whether buffered uplink data exists for one or more radio bearers of the first set of radio bearers, determining a set of random access resources and a set of random access parameters to be configured for an SDT in accordance with a determination that uplink data exists, determining a set of random access resources and a set of random access parameters to be configured for a non-SDT in accordance with a determination that buffered uplink data does not exist for the first set of radio bearers, and initiating the RRC restart procedure using the determined set of random access resources and the determined set of random access parameters.

[0150] In some embodiments, the circuitry may be further configured to: determine, after the initiation, that uplink data arrives from a second set of radio bearers that support MO-SDT and that are suspended; and send an indication to the other network device indicating the arrival of the uplink data.

[0151] In some embodiments, the circuitry may be further configured to receive another indication from the other network device indicating that the uplink data has been transmitted by the terminal device in the inactive state, resume the second set of radio bearers, perform PDCP re-establishment for PDCP entities of the second set of radio bearers, perform RLC re-establishment for RLC entities of the second set of radio bearers, and transmit the uplink data to the other network device in the inactive state.

[0152] In some embodiments, the circuitry is further configured to receive an RRC resume message from the other network device and, in a connected state, transmit the uplink data to the other network device, hi some embodiments, the other network device and the network device are the same network device.

[0153] In some embodiments, the network device comprises circuitry, the circuitry configured to send an RRC release message to the terminal device, the RRC release message including the configuration of a first set of radio bearers that support MT-SDT.

[0154] In some embodiments, the network device comprises circuitry configured to receive, from the terminal device, an indication indicating that uplink data has arrived from a second set of radio bearers that support MO-SDT and that are suspended.

[0155] In some embodiments, the circuitry may be further configured to send another indication to the terminal device indicating that the uplink data was transmitted by the terminal device in an inactive state, and to receive the uplink data transmitted by the terminal device in the inactive state.

[0156] In some embodiments, the circuitry may be further configured to send an RRC resume message to the terminal device and to receive the uplink data sent by the terminal device in a connected state.

[0157] As used herein, the term "circuitry" 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 yet another example, a circuit may be any portion of a hardware processor with software, including a digital signal processor, software, and one or more memories, that cooperate to cause a device, such as a terminal device or a network device, to perform various functions. In yet another example, a circuit may be a hardware circuit and / or a processor, such as a microprocessor or portion thereof, that requires software / firmware for operation, although the software may not be present if not necessary for operation. As used herein, the term "circuitry" also includes an implementation of a hardware circuit or one or more processors only, or a hardware circuit or portion of one or more processors and its / their accompanying software and / or firmware.

[0158] Overall, various 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 executable by a controller, microprocessor, or other computing device. While various aspects of embodiments of the present disclosure have been illustrated and described using block diagrams, flowcharts, or other pictorial representations, it should be understood that the blocks, devices, systems, techniques, or methods described herein may be implemented, by way of non-limiting example, in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing device, or any combination thereof.

[0159] 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 program modules, that execute within a device on a target real or virtual processor to perform the processes or methods described above with reference to Figures 3-10. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functionality of the program modules may be combined or split between program modules as desired. The machine-executable instructions of the program modules may be executed within local or distributed devices. In a distributed device, program modules may be located in both local and remote storage media.

[0160] Program code for carrying out 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 device, and when executed by the processor or controller, cause the program code to implement the functions / acts specified in the flowcharts and / or block diagrams. The program code may run entirely on the machine, partially on the machine, as a separate software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0161] The above-described program code may be embodied on a machine-readable medium, which may be any tangible medium that can contain or store a program used by or associated with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-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 aforementioned media. More specific examples of a machine-readable storage medium may include an electrical connection having 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 above.

[0162] Although operations have been described in a particular order, it should not be understood that performing these operations in the particular order shown, or in any sequential order, or performing all of the operations described, is required to achieve desirable results. In some cases, multitasking or parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Some features that are described in the context of individual 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 embodiments separately or in any suitable subcombination.

[0163] 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 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. 1. A method performed by a first network device that is a neighboring network device, comprising: receiving a radio access network (RAN) paging message from a second network device, the second network device being a last serving network device, the paging message including first information related to a mobile-terminated small data transmission (MT-SDT); determining whether to trigger the MT-SDT based on the first information; Based on the decision to trigger the MT-SDT, The method includes sending a paging message to a terminal device, the paging message including a first instruction regarding the MT-SDT, to initiate processing for the MT-SDT; Initiating the process for the MT-SDT includes: re-establishing a PDCP entity for the radio bearer established for the MT-SDT; resuming the radio bearer established for the MT-SDT; the first network device and the second network device are within a first RAN-based notification area (RNA); method.

2. The first information includes a second instruction regarding the MT-SDT and a size of downlink data. The method of claim 1.

3. The terminal device is in a Radio Resource Control (RRC) inactive state. The method of claim 1.

4. 1. A method performed by a terminal device, comprising: receiving a paging message from a first network device, the first network device being a neighboring network device, the paging message including a first indication for a mobile-terminated small data transmission (MT-SDT); Initiating a process for the MT-SDT; Radio Resource Control (RRC) including the restart reason for which the MT-SDT was set sending a (Resource Control) resume request message to the first network device; Initiating the process for the MT-SDT includes: re-establishing a PDCP entity for the radio bearer established for the MT-SDT; resuming the radio bearer established for the MT-SDT; The paging message is received from the first network device that has received a radio access network (RAN) paging message including first information about the MT-SDT from a second network device that is a last serving network device; the first network device and the second network device are within a first RAN-based notification area (RNA); A method comprising:

5. The first information includes a second instruction regarding the MT-SDT and a size of downlink data. The method of claim 4.

6. The terminal device is in a Radio Resource Control (RRC) inactive state. The method of claim 4.

7. Initiating the process for the MT-SDT includes: determining a set of random access resources not configured for the MT-SDT; initiating the transaction using the set of random access resources; 5. The method of claim 4, comprising:

8. a first network device that is a neighboring network device, one or more memories storing instructions; By processing the instruction, receiving a radio access network (RAN) paging message from a second network device, the second network device being a last serving network device, the paging message including first information related to a mobile-terminated small data transmission (MT-SDT); configured to control the first network device to determine whether to trigger the MT-SDT based on the first information. one or more processors; Based on the decision to trigger the MT-SDT, the one or more processors are configured to process the instructions to control the first network device to send a paging message to a terminal device, the paging message including a first instruction regarding the MT-SDT, to initiate processing for the MT-SDT; Initiating the process for the MT-SDT includes: re-establishing a PDCP entity for the radio bearer established for the MT-SDT; resuming the radio bearer established for the MT-SDT; the first network device and the second network device are within a first RAN-based notification area (RNA); A first network device.

9. The first information includes a second instruction regarding the MT-SDT and a size of downlink data. The first network device of claim 8 .

10. The terminal device is in a Radio Resource Control (RRC) inactive state. The first network device of claim 8 .

11. A terminal device, one or more memories storing instructions; By processing the instruction, receiving a paging message from a first network device, the paging message including a first indication for a mobile-terminated small data transmission (MT-SDT); Initiating processing for the MT-SDT; configured to control the terminal device to send a Radio Resource Control (RRC) resume request message to the first network device, the RRC request message including the resume reason configured by the MT-SDT. one or more processors; Equipped with Initiating the process for the MT-SDT includes: re-establishing a PDCP entity for the radio bearer established for the MT-SDT; resuming the radio bearer established for the MT-SDT; The paging message is received from the first network device that has received a radio access network (RAN) paging message including first information about the MT-SDT from a second network device that is a last serving network device; The first network device and the second network device are located within a first RAN-based notification area (RNA). Terminal device.

12. The first information includes a second instruction regarding the MT-SDT and a size of downlink data. The terminal device according to claim 11.

13. The terminal device is in a Radio Resource Control (RRC) inactive state. The terminal device according to claim 11.

14. The one or more processors process the instructions to: determining a set of random access resources not configured for the MT-SDT; configured to control the terminal device to initiate processing for the MT-SDT using the set of random access resources. The terminal device according to claim 11.

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