Method executed by a terminal device, and a terminal device

Abstract

Embodiments of the present disclosure relate to a communication method, a device, and a computer storage medium. The communication method implemented in a terminal device includes: determining configuration parameters for transmitting uplink data in an inactive state according to determining that the uplink data will be transmitted; determining a targeted random access procedure for transmitting the uplink data in the inactive state of the terminal device based on the configuration parameters; and transmitting the uplink data to a network device in the inactive state based on the targeted random access procedure. The communication method implemented in the network device includes receiving uplink data transmitted by a terminal device in an inactive state based on a targeted random access procedure, the targeted random access procedure being determined based on configuration parameters, the configuration parameters being determined when it is determined that the uplink data will be transmitted in the inactive state; and transmitting a response to the reception of the uplink data to the terminal device. This provides a control scheme for small data transmission based on a RACH.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of telecommunications, and more particularly, to a communication method, device, and computer storage medium for small data transmission (SDT) based on the random access channel (RACH).

Background Art

[0002] Generally, even a terminal device in an inactive state may have small-scale and low-frequency data traffic to be transmitted (hereinafter also referred to as SDT). Up to the 3rd Generation Partnership Project (3GPP) Release 16, data transmission could not be supported in the inactive state, and the terminal device had to resume connections for any downlink and uplink data. The establishment of a connection (setup) and subsequent release to the inactive state occur for each data transmission, regardless of how small and infrequent the data packet is. This leads to unnecessary power consumption and signal overhead.

[0003] In this regard, 3GPP's new radio (NR) Release 17 has approved RACH-based SDT in the inactive state. As is well known, NR is involved in 2-step random access procedures in addition to 4-step random access procedures. Therefore, how to implement SDT considering 2-step and 4-step random access procedures has become the focus of discussion.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, embodiments of the present disclosure provide a communication method, device, and computer storage medium for RACH-based SDT.

Means for Solving the Problems

[0005] In a first aspect, a communication method is provided. The method includes, at a terminal device, determining configuration parameters for transmission of the uplink data according to a determination that the uplink data is to be transmitted in a non-active state of the terminal device; determining a target random access procedure for transmission of the uplink data in the non-active state of the terminal device based on the configuration parameters; and transmitting the uplink data to a network device in the non-active state based on the target random access procedure.

[0006] In a second aspect, a communication method is provided. The method includes, at a network device, receiving uplink data transmitted by a non-active terminal device based on a target random access procedure, where the target random access procedure is determined based on configuration parameters, and the configuration parameters are determined when it is determined that the uplink data is to be transmitted in the non-active state; and transmitting a response to the reception of the uplink data to the terminal device.

[0007] In a third aspect, a terminal device is provided. The terminal device includes a processor and a memory coupled to the processor. Instructions are stored in the memory, and when executed by the processor, cause the terminal device to perform the method according to the first aspect of the present disclosure.

[0008] In a fourth aspect, a network device is provided. The network device includes a processor and a memory coupled to the processor. Instructions are stored in the memory, and when executed by the processor, cause the network device to perform the method according to the second aspect of the present disclosure.

[0009] In a fifth aspect, a computer-readable medium storing instructions is provided. When the instructions are executed on at least one processor, the at least one processor is caused to execute the method according to the first aspect of the present disclosure.

[0010] In a sixth aspect, a computer-readable medium storing instructions is provided. When the instructions are executed on at least one processor, the at least one processor is caused to execute the method according to the second aspect of the present disclosure.

[0011] Other features of the present disclosure should be readily understood through the following description.

Brief Description of the Drawings

[0012] The above and other objects, features, and advantages of the present disclosure should become more apparent through a more detailed description of some embodiments of the present disclosure in the accompanying drawings.

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[0031] Throughout the drawings, the same or similar reference numerals represent the same or similar elements.

Best Mode for Carrying Out the Invention

[0032] The principles of the present disclosure will be described with reference to several embodiments. It should be understood that these embodiments are described for illustrative purposes only and are useful for those skilled in the art to understand and implement the present disclosure, and do not imply any limitation to the scope of the present disclosure. The present disclosure described herein can be implemented in various ways other than those described below.

[0033] In the following description and claims, unless otherwise defined, all technical and scientific terms used have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0034] As used herein, the term "terminal device" refers to any device having a wireless or wired communication function. Examples of terminal devices include, but are not limited to, user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, personal digital assistants (PDAs), portable computers, tablets, wearable devices, Internet of Things (IoT) devices, Internet of Everything (IoE) devices, machine type communication (MTC) devices, vehicle-mounted devices for vehicle-to-everything (V2X) communication (where X means pedestrian, vehicle, or infrastructure / network), imaging devices such as digital cameras, gaming devices, music storage / playback devices, Internet devices enabling wireless / wired Internet access and browsing, etc. The term "terminal device" can be used interchangeably with UE, mobile station, subscriber equipment, mobile terminal, user terminal, or wireless device. Also, the term "network device" refers to a device capable of providing or hosting a cell or coverage with which a terminal device can communicate. Examples of network devices include, but are not limited to, Node B (NodeB or NB), Evolved NodeB (eNodeB or eNB), next-generation NodeB (gNB), transmission and reception point (TRP), remote radio unit (RRU), radio head (RH), remote radio head (RRH), femto node, low-power nodes such as pico nodes, etc.

[0035] In one embodiment, the terminal device may be connected 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 may be a secondary node. The first network device and the second network device may use different 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 different RATs may be transmitted from at least one of the first network device and the second network device to the terminal 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 directly transmitted from the second network device to the terminal device or transmitted via the first network device. In one embodiment, information related to the settings of the terminal device set by the second network device may be transmitted from the second network device via the first network device. Information related to the re - setting of the terminal device set by the second network device may be directly transmitted from the second network device to the terminal device or transmitted via the first network device.

[0036] As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "comprising" and its variations are to be construed as an open - ended term meaning "including, but not limited to". The term "based on" is construed as "at least partially based on". The terms "one embodiment" and "an embodiment" are construed as "at least one embodiment". The term "another embodiment" is construed as "at least one other embodiment". The terms "first", "second", etc. may refer to different objects or the same object. There may be other explicit and implicit definitions included in the following content.

[0037] In some examples, a value, process, or apparatus is referred to as "optimal," "lowest," "highest," "minimum," "maximum," etc. It should be understood that such descriptions are intended to indicate that among the multiple functional alternatives used, such a selection may be possible, and such a selection does not necessarily have to be better, smaller, higher, or more preferable than other selections.

[0038] FIG. 1 shows a schematic diagram of an exemplary communication network 100 capable of implementing an embodiment of the present disclosure. As shown in FIG. 1, the communication network 100 includes a network device 110 and a terminal device 120 to which the network device 110 provides services. The network device 110 and the terminal device 120 may communicate via a channel such as a wireless communication channel. For example, the terminal device 120 may transmit data packets (i.e., uplink data) to the network device 110, and the network device 110 may transmit a response to the reception of the uplink data to the terminal device 120.

[0039] It should be understood that the number and types of devices in FIG. 1 are shown for illustrative purposes and do not imply any limitation to the present disclosure. The communication network 100 may include any suitable number of network devices and / or terminal devices that are compatible with the implementation of the present disclosure. Further, the communication network 100 may include any device other than network devices and terminal devices, such as core network elements, but is omitted in this specification to avoid obscuring the present invention.

[0040] Communications in the communication network 100 may comply with any suitable standard. These standards include, but are not limited to, the Global System for Mobile Communications (GSM) for mobile communications, 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, the communication may be performed according to any generation of communication protocol known currently or developed in the future. Examples of communication protocols include, but are not limited to, the communication protocols of the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, and fifth generation (5G).

[0041] As described above, even the terminal device 120 in the inactive state may have small-scale and low-frequency data traffic (hereinafter also referred to as SDT) to be transmitted. In some embodiments, the small-scale and low-frequency data traffic may include traffic from instant messaging (IM) services (such as whatsapp, QQ, wechat, etc.), heart beat / keep-alive traffic from IM / mail clients and other applications, push notifications from various applications, etc., of smartphone applications. In some embodiments, the small-scale and low-frequency data traffic may include applications other than smartphones, such as traffic from wearable devices (such as periodic location information, etc.), sensors (such as industrial wireless sensor networks that transmit temperature and pressure measurement values periodically or in an event-triggered manner), smart meters that transmit periodic meter measurement values, and traffic from smart meter networks.

[0042] Currently, a RACH-based method is approved for executing SDT when the terminal device is inactive. Since NR is involved in both the two-step random access procedure and the four-step random access procedure, how to execute SDT considering the two-step and four-step random access procedures has become the focus of discussion. Embodiments of the present disclosure provide a communication solution for RACH-based SDT. This solution can realize the control of SDT considering the two-step random access procedure and the four-step random access procedure. The principle and implementation of the present disclosure will be described in detail below with reference to the drawings.

[0043] FIG. 2 shows a schematic diagram showing a communication process 200 for RACH-based SDT according to some embodiments of the present disclosure. For the purpose of discussion, the process 200 will be described with reference to FIG. 1. The process 200 may be related to the terminal device 120 and the network device 110 shown in FIG. 1.

[0044] As shown in FIG. 2, when the terminal device 120 in the inactive state has data packets to be transmitted (i.e., uplink data), the terminal device 120 determines (210) whether the uplink data is to be transmitted in the inactive state. In some embodiments, the terminal device 120 may determine whether the size of the buffered content related to the uplink data is less than or equal to a threshold size. That is, the terminal device 120 may check the actual data size, i.e., the size of the buffered content. In some embodiments, the buffered content may refer to all uplink data, signaling available for transmission, a media access control (MAC) header, and, if necessary, a MAC control element (CE).

[0045] In some embodiments, the threshold size is the maximum buffer size of the SDT. The threshold size is a threshold value and may be determined by any suitable method. In some embodiments, the threshold size may be broadcast by system information from the network device 110. In some alternative embodiments, the threshold size may be a predetermined value. In some alternative embodiments, a threshold size supporting the SDT may be set in the terminal device 120.

[0046] When it is determined that the size of the buffered content is larger than the threshold size, the terminal device 120 may cancel the transmission of uplink data in the inactive state. In some embodiments, at the MAC layer of the terminal device 120, when it is determined that the size of the buffered content is larger than the threshold size, the MAC layer may indicate the cancellation to the upper layer (i.e., the radio resource control (RRC) layer of the terminal device 120). Upon receiving the cancellation indication from the lower layer (i.e., the MAC layer), the RRC layer may start normal data transmission (NDT). In this case, the terminal device 120 may transmit uplink data in the connected state.

[0047] It should be noted that the above is merely an example, and any other suitable method can also be implemented to determine whether uplink data is transmitted in the inactive state.

[0048] When it is determined that uplink data is to be transmitted in the inactive state, the terminal device 120 determines (220) the configuration parameters for the transmission of the uplink data. In some embodiments, the determination of the configuration parameters may include a selection between the normal uplink (NUL) and the supplementary uplink (SUL) for the uplink data transmission, and a selection of the bandwidth part (BWP) for the selected uplink. The SUL may be arranged to improve the UL coverage for high-frequency scenarios. With the SUL, two ULs may be configured for one DL of the same cell for the terminal device 120. The SUL can be used when the terminal device 120 is at the edge of the cell, and the NUL can be used when the terminal device 120 is in the center of the cell. According to the embodiments of the present disclosure, the actual size of the uplink data is confirmed before the determination of the configuration parameters. Thereby, efficient data transmission can be realized without wasting unnecessary resources.

[0049] Based on the determined configuration parameters, the terminal device 120 determines (230) a target random access procedure for uplink data transmission in the inactive state. In some embodiments, the target random access procedure may be a two-step random access procedure. In some embodiments, the two-step random access procedure may be a contention based random access procedure. FIG. 17 shows a schematic diagram 1700 of a two-step random access procedure according to some embodiments of the present disclosure. As shown in FIG. 17, the two-step random access procedure may involve the transmission of a message A (msgA) from the terminal device 120 to the network device 110 and the transmission of a message B (msgB) from the network device 110 to the terminal device 120 as a response to the message A. The message A may include a random access preamble transmission 1701 and a PUSCH payload transmission 1702 of a random access procedure for a two-step random access (RA) type. The message B may be composed of a response 1703 for one or more of contention resolution, fallback indication, and backoff indication.

[0050] In some embodiments, the target random access procedure may be a four-step random access procedure. In some embodiments, the four-step random access procedure may be a contention-based random access procedure. FIG. 18 shows a schematic diagram 1800 of a four-step random access procedure according to some embodiments of the present disclosure. As shown in FIG. 18, the four-step random access procedure may involve the transmission of message 1 (msg1) and message 3 (msg3) from the terminal device 120 to the network device 110, and the transmission of message 2 (msg2) and message 4 (msg4) from the network device 110 to the terminal device 120 as responses to message 1 and message 3, respectively. Message 1 may be composed of a random access preamble transmission 1801 for a four-step RA type random access procedure. Message 2 may include a random access response (RAR) 1802. The RAR may include configured grant information for data transmission. Message 3 may include a first schedule transmission 1803 of the random access procedure. Message 4 may be composed of a response 1804 for one or more of contention resolution, fallback indication, and backoff indication.

[0051] According to an embodiment of the present disclosure, the determination of the target random access procedure can be performed based on the random access resource setting and packet size of the SDT in two-step and four-step random access procedures.

[0052] SDT Random Access Resource Configuration

[0053] In some embodiments, dedicated RACH resources may be configured for SDT in each of the two-step random access procedure and the four-step random access procedure. That is, SDT is not shared with NDT in the RACH resources. Here, the RACH resources refer to the resources related to RACH transmission. For example, the RACH resources may include at least one of time-frequency resources and preamble resources. It should be noted that other resources related to RACH transmission can also be included. In some embodiments, the dedicated RACH resources may be a set of resources, and the resources in the set are associated with different uplink grant sizes. Thereby, a flexible payload size can be enabled.

[0054] In some additional or alternative embodiments, in message A of the two-step random access procedure, dedicated physical uplink shared channel (PUSCH) resources may be configured for SDT. That is, SDT is not shared with NDT in the PUSCH resources of message A of the two-step random access procedure. In some embodiments, the dedicated PUSCH resources may be a set of resources, and the resources in the set are associated with different uplink grant sizes. Thereby, a flexible payload size can be enabled.

[0055] The dedicated random access resources for SDT can indicate to network device 110 that this is an SDT transmission.

[0056] In some alternative embodiments for the two-step random access procedure, the random access resources can be shared between SDT and NDT. In some embodiments, at least one of the RACH resources and the PUSCH resources can be shared between SDT and NDT. The shared random access resources can improve the efficiency of radio resources and enable radio resource savings.

[0057] SDT Packet Size

[0058] As described above, dedicated random resources corresponding to different uplink grant sizes may be set by the network device 110. The terminal device 120 may determine the packet size of the SDT in order to select one appropriate random resource therefrom. Here, the packet size may refer to the size of the data packet first transmitted in the SDT. If the uplink grant size is too large for the data packet, padding is added and the power consumption increases. If the uplink grant size is too small, multiple transmissions are required. In consideration of this point, according to an embodiment of the present disclosure, the terminal device 120 may determine the packet size of the SDT when starting the SDT.

[0059] In some embodiments, the terminal device 120 may receive the packet size from the network device 110. For example, information about the packet size may be broadcast by system information from the network device 110. Alternatively, information about the packet size may be set for the terminal device 120 by an RRC message such as an RRCRelease message or any other appropriate message. Further, the packet size may be associated with at least one of the access category of the uplink data, the access identity, the QoS parameter (5QI), and the data radio bearer (DRB).

[0060] In some alternative embodiments, the terminal device 120 may determine the packet size of the uplink data based on the characteristics of the traffic associated with the uplink data. In some embodiments, the RRC layer of the terminal device 120 may determine the packet size of the uplink data. For example, the RRC layer determines the packet size based on at least one of the traffic characteristics such as the access category of the uplink data, the access identity, the QoS parameter (5QI), and the data radio bearer (DRB) identity (ID), and notifies the lower layer (i.e., the MAC layer) of the packet size to assist, for example, in determining the target random access procedure. Alternatively, the MAC layer of the terminal device 120 may determine the packet size of the uplink data. For example, the MAC layer receives assistance information about the traffic characteristics provided from the upper layer (i.e., the RRC layer), such as at least one of the access category of the uplink data, the access identity, the QoS parameter (5QI), and the data radio bearer (DRB) identity (ID), and may determine the packet size based on the assistance information.

[0061] The MAC layer may utilize the packet size to assist in determining the target random access procedure. For example, the uplink grant size of the dedicated random access resource must be equal to the packet size. Alternatively, the target random access procedure may be determined regardless of the packet size. Details regarding the determination of the target random access procedure will be described later in connection with FIGS. 4 to 9B.

[0062] Referring to FIG. 2, when the target random access procedure is determined (230), the terminal device 120 transmits uplink data based on the target random access procedure in the inactive state (240). For example, the terminal device 120 may determine the random access resource of the target random access procedure and transmit uplink data using the determined resource. In some embodiments, the terminal device 120 may transmit uplink data according to the packet size. In some embodiments, the terminal device 120 may transmit uplink data regardless of the packet size. Details regarding uplink data transmission will be described later in relation to FIGS. 10 and 11A - 11B.

[0063] Upon receiving the uplink data, the network device 110 transmits a response to the terminal device 120 for the reception of the uplink data (250). In some embodiments, in this response, the terminal device 120 may be notified to suspend the radio bearer for SDT transmission. In some embodiments, in this response, the terminal device 120 may be notified of uplink grant information for subsequent transmission of uplink data. It should be noted that any other suitable response form can also be implemented.

[0064] Corresponding to the above - described process, embodiments of the present disclosure provide communication methods implemented in a terminal device and a network device respectively. This will be described in more detail with reference to FIGS. 3 - 15.

[0065] FIG. 3 shows an exemplary communication method 300 implemented in a terminal device according to some embodiments of the present disclosure. For example, method 300 may be executed on the terminal device 120 as shown in FIG. 1. For the purpose of discussion, method 300 will be described below with reference to FIG. 1. Method 300 may include additional blocks not shown and / or may omit some of the shown blocks, and it should be understood that the scope of the present disclosure is not limited in this regard.

[0066] As shown in FIG. 3, in block 310, the terminal device 120 determines whether uplink data is transmitted in an inactive state. In this way, it is possible to check whether the SDT is started. If it is determined in block 310 that the uplink data is transmitted in an inactive state, then in block 320, the terminal device 120 determines the setting parameters for uplink data transmission. In some embodiments, the terminal device 120 may perform a selection between NUL and SUL for uplink data transmission and select a BWP for the selected uplink. It should be noted that in relation to the selection of the uplink and the selection of the bandwidth, any other appropriate setting parameters may be determined. The operation in block 310 is the same as that described in 210 in relation to FIG. 2, and other details are not repeated here.

[0067] In block 330, the terminal device 120 may determine a target random access procedure based on the setting parameters. The terminal device 120 may determine which of the two-step or four-step random access procedures is used under the setting parameters. In some embodiments, the determination of the target random access procedure may be performed based on the random access resources and packet sizes of the SDT in the two-step and four-step random access procedures. This will be described in detail in relation to FIGS. 4 to 6B. In some embodiments, the terminal device 120 may receive information about the packet size of the uplink data from the network device 110. In some alternative embodiments, the terminal device 120 may determine the packet size of the uplink data based on the characteristics of the traffic associated with the uplink data. In some additional embodiments, the packet size is associated with at least one of the access category, access identity, QoS parameter, and data radio bearer of the uplink data.

[0068] In some alternative embodiments, the determination of the target random access procedure at block 330 may be performed based on the random access resources for SDT and the size of the common control channel (CCCH) messages in the 2-step and 4-step random access procedures. This will be described in detail later in connection with FIGS. 7 to 9B. The operation at block 330 is the same as that described at 230 in connection with FIG. 2, and other details will not be repeated here.

[0069] At block 340, the terminal device 120 transmits uplink data to the network device 110 based on the target random access procedure in the inactive state. For example, the terminal device 120 may determine the random access resources of the target random access procedure and transmit the uplink data using the determined resources. In some embodiments, the terminal device 120 may transmit the uplink data according to the packet size. Details thereof will be described later in connection with FIG. 10. In some embodiments, the terminal device 120 may transmit the uplink data regardless of the packet size. Details thereof will be described later in connection with FIGS. 11A to 11B. The operation at block 340 is the same as that described at 240 in connection with FIG. 2, and other details will not be repeated here.

[0070] Determination of Target Random Access Procedure Based on Packet Size

[0071] FIG. 4 shows an exemplary method 400 for determining a target random access procedure based on a packet size according to some embodiments of the present disclosure. For example, method 400 may be executed on the terminal device 120 as shown in FIG. 1. For the purpose of discussion, method 400 will be described below with reference to FIG. 1. Method 400 may include additional blocks not shown and / or may omit some of the blocks shown, and it should be understood that the scope of the present disclosure is not limited in this regard. In the present embodiment, a case where a random access resource for a two-step random access procedure is mainly set will be described, and in particular, a case where only a random access resource for a two-step random access procedure is set will be described.

[0072] As shown in FIG. 4, at block 410, the terminal device 120 determines whether a random access resource (also referred to herein as a first random access resource) for a two-step random access procedure is set for the selected BWP. In some embodiments, if only the first random access resource is set, the terminal device 120 may determine that the first random access resource is set.

[0073] If the first random access resource is set, at block 420, the terminal device 120 may determine whether a dedicated resource of the first random access resource (also referred to herein as a first dedicated resource) is set for uplink data transmission (i.e., SDT) in the inactive state. In some embodiments, the terminal device 120 determines whether the first dedicated resource has a size corresponding to the packet size for SDT, and if it is determined that the first dedicated resource has a size corresponding to the packet size, the terminal device 120 may determine that the first dedicated resource is set. This is merely an example, and it should be noted that any other suitable method may be implemented to determine whether the first dedicated resource is set.

[0074] If it is determined in block 420 that the first dedicated resource is set, in block 430, the terminal device 120 may determine the two-step random access procedure as the target random access procedure. If it is determined in block 420 that the first dedicated resource is not set, in block 440, the terminal device 120 may determine whether the PUSCH resource for the two-step random access procedure for the selected BWP can accommodate at least the packet size.

[0075] In block 440, if it is determined that the PUSCH resource can accommodate at least the packet size, the terminal device 120 may determine the two-step random access procedure as the target random access procedure. In block 440, if it is determined that the PUSCH resource cannot accommodate at least the packet size, in block 450, the terminal device 120 may cancel the uplink data transmission in the inactive state.

[0076] FIG. 5 shows another exemplary method 500 for determining a target random access procedure based on a packet size according to some embodiments of the present disclosure. For example, the method 500 may be executed by the terminal device 120 as shown in FIG. 1. For the purpose of discussion, the method 500 will be described below with reference to FIG. 1. The method 500 may include additional blocks not shown and / or may omit some of the blocks shown, and it should be understood that the scope of the present disclosure is not limited in this regard. In the present embodiment, a case where the random access resource for the four-step random access procedure is mainly set will be described, and in particular, a case where only the random access resource for the four-step random access procedure is set will be described.

[0077] As shown in FIG. 5, in block 510, the terminal device 120 determines whether a random access resource (also referred to herein as a second random access resource) for a 4-step random access procedure is set for the selected BWP. In some embodiments, if only the second random access resource is set, the terminal device 120 may determine that the second random access resource is set.

[0078] If the second random access resource is set, in block 520, the terminal device 120 may determine whether a dedicated resource (also referred to herein as a second dedicated resource) of the second random access resource is set for uplink data transmission (i.e., SDT) in the non-active state. In some embodiments, the terminal device 120 determines whether the second dedicated resource has a size corresponding to the packet size for SDT, and if it is determined that the second dedicated resource has a size corresponding to the packet size, the terminal device 120 may determine that the second dedicated resource is set. It should be noted that this is merely an example, and any other suitable method may be implemented to determine whether the second dedicated resource is set.

[0079] If it is determined in block 520 that the second dedicated resource is set, in block 530, the terminal device 120 may determine the 4-step random access procedure as the target random access procedure. If it is determined in block 520 that the second dedicated resource is not set, in block 540, the terminal device 120 may cancel the uplink data transmission in the non-active state.

[0080] Figures 6A-6B illustrate another exemplary method 600 for determining a target random access procedure based on packet size, according to some embodiments of the present disclosure. For example, method 600 may be executed on the terminal device 120 as shown in FIG. 1. For the purpose of discussion, method 600 will be described below with reference to FIG. 1. Method 600 may include additional blocks not shown and / or may omit some of the blocks shown, and it should be understood that the scope of the present disclosure is not limited in this regard. In the present embodiment, a case where both a first random access resource for a two-step random access procedure and a second random access resource for a four-step random access procedure are set will be described.

[0081] As shown in FIG. 6A, at block 601, the terminal device 120 determines whether both a first random access resource for a two-step random access procedure and a second random access resource for a four-step random access procedure are set for the selected BWP. If it is determined that both the first random access resource and the second random access resource are set, at block 602, the terminal device 120 may determine whether a first dedicated resource in the first random access resource is set for uplink data transmission in the non-active state, and whether the reference signal received power (RSRP) of the downlink reference signal (DL RS) exceeds a threshold power. The threshold power is a threshold value and can be determined by any suitable method.

[0082] In some embodiments, the terminal device 120 determines whether the first dedicated resource has a size corresponding to the packet size, and if it is determined that the first dedicated resource has a size corresponding to the packet size, the terminal device 120 may determine that the first dedicated resource is set. This is merely an example, and it should be noted that any other suitable method may also be implemented to determine whether the first dedicated resource is set.

[0083] In block 602, if it is determined that the first dedicated resource is set and the RSRP exceeds the threshold power, in block 603, the terminal device 120 may determine the two-step random access procedure as the target random access procedure. In block 602, if it is determined that the first dedicated resource is not set or the RSRP is below the threshold power, in block 604, the terminal device 120 may determine whether the second dedicated resource in the second random access resource is set for uplink data transmission in the inactive state.

[0084] In some embodiments, the terminal device 120 determines whether the second dedicated resource has a size corresponding to the packet size, and if it is determined that the second dedicated resource has a size corresponding to the packet size, the terminal device 120 may determine that the second dedicated resource is set. It should be noted that this is merely an example, and any other suitable method may be implemented to determine whether the second dedicated resource is set.

[0085] If it is determined in block 604 that the second dedicated resource is set, in block 605, the terminal device may determine the four-step random access procedure as the target random access procedure. If it is determined in block 604 that the second dedicated resource is not set, in block 606, the terminal device 120 may determine whether the PUSCH resource for the two-step random access procedure for the selected BWP can accommodate at least a part of the packet size, and whether the RSRP of the downlink reference signal exceeds the threshold power.

[0086] In block 606, if the PUSCH resource can accommodate at least a part of the packet size and it is determined that the RSRP exceeds the threshold power, the process proceeds to block 603, and the terminal device 120 may determine the two-step random access procedure as the target random access procedure. In block 606, if the PUSCH resource for the two-step random access procedure for the selected BWP cannot accommodate at least a part of the packet size of the uplink data or it is determined that the RSRP is below the threshold power, in block 607 as shown in FIG. 6B, the terminal device 120 may determine whether a first dedicated resource in the first random access resource is set for uplink data transmission in the inactive state.

[0087] In some embodiments, the terminal device 120 determines whether the first dedicated resource has a size corresponding to the packet size, and if it is determined that the first dedicated resource has a size corresponding to the packet size, the terminal device 120 may determine that the first dedicated resource is set. It should be noted that this is merely an example, and any other suitable method may be implemented to determine whether the first dedicated resource is set.

[0088] If it is determined in block 607 that the first dedicated resource is set, the process proceeds to block 603, and the terminal device 120 may determine the two-step random access procedure as the target random access procedure. If it is determined in block 607 that the first dedicated resource is not set, in block 608, the terminal device 120 may determine whether the PUSCH resource for the two-step random access procedure for the selected BWP can accommodate at least a part of the packet size.

[0089] In block 608, if it is determined that the PUSCH resource can accommodate at least a part of the packet size of the uplink data, the process proceeds to block 603, and the terminal device 120 may determine the two-step random access procedure as the target random access procedure. In block 608, if it is determined that the PUSCH resource cannot accommodate at least a part of the packet size of the uplink data, in block 609, the terminal device 120 may cancel the uplink data transmission in the inactive state.

[0090] In an alternative embodiment, the operations in block 607 and the operations in block 608 can be reversed in execution order. That is, the determination in block 608 may be executed first, and then the determination in block 607 may be executed. It should be noted that the embodiments described in connection with FIGS. 4 to 6B are merely illustrative and may be combined with any suitable method for determining the target random access procedure.

[0091] Determination of Target Random Access Procedure Regardless of Packet Size

[0092] FIG. 7 shows an exemplary method 700 for determining a target random access procedure regardless of the packet size according to some embodiments of the present disclosure. For example, the method 700 may be executed by the terminal device 120 as shown in FIG. 1. For the purpose of discussion, the method 700 will be described below with reference to FIG. 1. The method 700 may include additional blocks not shown and / or some of the shown blocks may be omitted, and it should be understood that the scope of the present disclosure is not limited in this regard. In this embodiment, a case where a random access resource for mainly a two-step random access procedure is set will be described, and in particular, a case where only a random access resource for a two-step random access procedure is set will be described.

[0093] As shown in FIG. 7, in block 710, the terminal device 120 determines whether a first random access resource for a two-step random access procedure is set for the selected BWP. In some embodiments, if only the first random access resource is set, the terminal device 120 may determine that the first random access resource is set.

[0094] If the first random access resource is set, in block 720, the terminal device 120 may determine whether a first dedicated resource in the first random access resource is set for uplink data transmission in the non-active state. Comparing with the operation in block 420 of FIG. 4, in the operation in block 720, there is no restriction on the size of the first dedicated resource.

[0095] If it is determined in block 720 that the first dedicated resource is set, in block 730, the terminal device 120 may determine the two-step random access procedure as the target random access procedure. If it is determined in block 720 that the first dedicated resource is not set, in block 740, the terminal device 120 may determine whether the size of the PUSCH resource for the two-step random access procedure for the selected BWP is larger than the size of the CCCH message. Comparing with the operation in block 440 of FIG. 4, in the operation of block 740 , instead of the packet size of the uplink data, the size of the CCCH message is used to assist in determining the target random access procedure.

[0096] In block 740, if it is determined that the size of the PUSCH resource is larger than the size of the CCCH message, the terminal device 120 may determine the two-step random access procedure as the target random access procedure. In block 740, if the size of the PUSCH resource is the size of the CCCH message Are as FollowsWhen it is determined that way, in block 750, the terminal device 120 may cancel uplink data transmission in the inactive state.

[0097] In an alternative embodiment, the operations in block 720 and the operations in block 740 can be reversed in the execution order. That is, the determination in block 740 may be executed first, and then the determination in block 720 may be executed.

[0098] FIG. 8 shows another exemplary method 800 for determining a target random access procedure regardless of packet size according to some embodiments of the present disclosure. For example, method 800 may be executed on the terminal device 120 as shown in FIG. 1. For the purpose of discussion, method 800 will be described below with reference to FIG. 1. Method 800 may include additional blocks not shown and / or may omit some of the blocks shown, and it should be understood that the scope of the present disclosure is not limited in this regard. In the present embodiment, a case where a random access resource for a 4-step random access procedure is mainly set will be described, and in particular, a case where only a random access resource for a 4-step random access procedure is set will be described.

[0099] As shown in FIG. 8, in block 810, the terminal device 120 determines whether a second random access resource for a 4-step random access procedure is set for the selected BWP. In some embodiments, when only the second random access resource is set, the terminal device 120 may determine that the second random access resource is set.

[0100] When the second random access resource is configured, at block 820, the terminal device 120 may determine whether a second dedicated resource in the second random access resource is configured for uplink data transmission in the inactive state. Compared with the operation at block 520 of FIG. 5, in the operation at block 820, there is no restriction on the size of the second dedicated resource.

[0101] If it is determined at block 820 that the second dedicated resource is configured, at block 830, the terminal device 120 may determine the 4-step random access procedure as the target random access procedure. If it is determined at block 820 that the second dedicated resource is not configured, at block 840, the terminal device 120 may cancel the uplink data transmission in the inactive state.

[0102] FIGS. 9A - 9B show another exemplary method 900 for determining a target random access procedure regardless of the packet size according to some embodiments of the present disclosure. For example, method 900 may be executed on the terminal device 120 as shown in FIG. 1. For the purpose of discussion, method 900 will be described below with reference to FIG. 1. Method 900 may include additional blocks not shown and / or may omit some of the blocks shown, and it should be understood that the scope of the present disclosure is not limited in this regard. In this embodiment, a case where both a first random access resource for a 2-step random access procedure and a second random access resource for a 4-step random access procedure are configured will be described.

[0103] As shown in FIG. 9A, in block 901, the terminal device 120 determines whether both a first random access resource for a two-step random access procedure and a second random access resource for a four-step random access procedure are set for the selected BWP. If it is determined that both the first random access resource and the second random access resource are set, in block 902, the terminal device 120 may determine whether a first dedicated resource in the first random access resource is set and whether the reference signal received power (RSRP) of the downlink reference signal (DL RS) exceeds a threshold power for uplink data transmission in the non-active state. Compared with the operation in block 602 of FIG. 6A, in the operation in block 902, there is no restriction on the size of the first dedicated resource.

[0104] In block 902, if it is determined that the first dedicated resource is set and the RSRP exceeds the threshold power, in block 903, the terminal device 120 may determine the two-step random access procedure as the target random access procedure. In block 902, if it is determined that the first dedicated resource is not set or the RSRP is below the threshold power, in block 904, the terminal device 120 may determine whether a second dedicated resource in the second random access resource is set for uplink data transmission in the non-active state. Compared with the operation in block 604 of FIG. 6A, in the operation in block 904, there is no restriction on the size of the second dedicated resource.

[0105] If it is determined in block 904 that a second dedicated resource is configured, in block 905, the terminal device may determine the 4-step random access procedure as the target random access procedure. If it is determined in block 904 that the second dedicated resource is not configured, in block 906, the terminal device 120 may determine whether the size of the PUSCH resource for the 2-step random access procedure for the selected BWP is larger than the size of the CCCH message, and whether the RSRP of the downlink reference signal exceeds the threshold power. Compared with the operation in block 606 of FIG. 6A, in the operation of block 906, the size of the CCCH message is used instead of the packet size of the uplink data to assist in determining the target random access procedure.

[0106] In block 906, if it is determined that the size of the PUSCH resource is larger than the size of the CCCH message and the RSRP exceeds the threshold power, the process proceeds to block 903, and the terminal device 120 may determine the 2-step random access procedure as the target random access procedure. In block 906, if it is determined that the size of the PUSCH resource is less than or equal to the size of the CCCH message, or the RSRP is below the threshold power, in block 907 as shown in FIG. 9B, the terminal device 120 may determine whether a first dedicated resource is configured in the first random access resource for uplink data transmission in the inactive state. Compared with the operation in block 607 of FIG. 6B, in the operation of block 907, there is no restriction on the size of the first dedicated resource.

[0107] If it is determined in block 907 that the first dedicated resource is set, the process proceeds to block 903, and the terminal device 120 may determine the two-step random access procedure as the target random access procedure. If it is determined in block 907 that the first dedicated resource is not set, in block 908, the terminal device 120 may determine whether the size of the PUSCH resource for the two-step random access procedure for the selected BWP is larger than the size of the CCCH message.

[0108] In block 908, if it is determined that the size of the PUSCH resource is larger than the size of the CCCH message, the process proceeds to 903, and the terminal device 120 may determine the two-step random access procedure as the target random access procedure. In block 908, if it is determined that the size of the PUSCH resource is less than or equal to the size of the CCCH message, in block 909, the terminal device 120 may cancel the uplink data transmission in the inactive state.

[0109] In an alternative embodiment, the operations in block 907 and the operations in block 908 can be reversed in execution order. That is, the determination in block 908 may be executed first, and then the determination in block 907 may be executed. It should be noted that the embodiments described in connection with FIGS. 7 to 9B are merely exemplary and may be combined with any suitable method for determining the target random access procedure.

[0110] Transmission of Uplink Data Based on RACH According to Packet Size

[0111] FIG. 10 shows an exemplary method 1000 for transmitting uplink data based on a target random access procedure according to some embodiments of the present disclosure. For example, method 1000 may be executed on the terminal device 120 as shown in FIG. 1. For the purpose of discussion, method 1000 will be described below with reference to FIG. 1. Method 1000 may include additional blocks not shown and / or may omit some of the blocks shown, and it should be understood that the scope of the present disclosure is not limited in this regard. In this embodiment, mainly, a case considering the packet size of uplink data will be described.

[0112] As shown in FIG. 10, in block 1001, the terminal device 120 may determine whether the target random access procedure is a two-step random access procedure or a four-step random access procedure. For example, the terminal device 120 may make the determination by any of methods 400-900 described in connection with FIGS. 4-9B.

[0113] If it is determined that the target random access procedure is a two-step random access procedure, the process proceeds to block 1002. In block 1002, the terminal device 120 may determine whether a dedicated random access resource is set for uplink data transmission (i.e., SDT) in the inactive state. In some embodiments, the terminal device 120 determines whether the dedicated random access resource has a size corresponding to the packet size of the uplink data, and according to the determination that the dedicated random access resource has a size corresponding to the packet size of the uplink data, the terminal device 120 may determine that the dedicated random access resource is set. This is merely an example, and it should be noted that any other suitable method may be implemented to determine whether the dedicated random access resource is set.

[0114] If it is determined that the dedicated random access resource is set in block 1002, in block 1003, the terminal device 120 may determine a preamble, a random access opportunity, and a PUSCH resource from the dedicated random access resource. According to an embodiment of the present disclosure, the random access resource here may include a RACH resource and a PUSCH resource. The RACH resource may include a preamble and time-frequency resources. Thereby, based on the dedicated random access resource for SDT, the terminal device 120 can determine the corresponding preamble, random access opportunity, and PUSCH resource for SDT.

[0115] If it is determined that the dedicated random access resource is not set in block 1002, in block 1004, the terminal device 120 may determine a preamble, a random access opportunity, and a PUSCH resource from a random access resource having a PUSCH resource capable of accommodating the packet size of the uplink data.

[0116] After determining the preamble, the random access opportunity, and the PUSCH resource, in block 1005, the terminal device 120 may transmit the preamble and the uplink data based on the determined random access opportunity and the determined PUSCH resource. This may correspond to transmitting message A in the two-step random access procedure. Thus, based on the two-step random access procedure, uplink data is transmitted in the inactive state.

[0117] If it is determined in block 1001 that the target random access procedure is a 4-step random access procedure, the process proceeds to block 1006. In block 1006, the terminal device 120 may determine a preamble and a random access opportunity from a random access resource dedicated to uplink data transmission in the inactive state. In some embodiments, the terminal device 120 determines whether the random access resource has a size corresponding to the packet size of the uplink data, and according to the determination that the random access resource has a size corresponding to the packet size of the uplink data, the terminal device 120 may determine that the random access resource is set. This is merely an example, and it should be noted that any other suitable method may be implemented to determine whether the random access resource is set.

[0118] In block 1007, the terminal device 120 may transmit a preamble based on the random access opportunity. In block 1008, the terminal device 120 may receive a response to the preamble from the network device. In some embodiments, the response may include uplink grant information for uplink data transmission. In block 1009, the terminal device 120 may transmit uplink data based on the response. Thus, based on the 4-step random access procedure, uplink data is transmitted in the inactive state.

[0119] Transmission of Uplink Data Based on RACH Regardless of Packet Size

[0120] Figures 11A - 11B illustrate an exemplary method 1100 for transmitting uplink data based on a target random access procedure regardless of packet size, according to some embodiments of the present disclosure. For example, method 1100 may be executed on the terminal device 120 as shown in FIG. 1. For the purpose of discussion, method 1100 will be described below with reference to FIG. 1. Method 1100 may include additional blocks not shown and / or may omit some of the blocks shown, and it should be understood that the scope of the present disclosure is not limited in this regard. In this embodiment, mainly, the case considering the packet size of the uplink data will be described. Do Not The case will be described.

[0121] As shown in FIG. 11A, in block 1101, the terminal device 120 may determine whether the target random access procedure is a two - step random access procedure or a four - step random access procedure. For example, the terminal device 120 may make that determination according to any of the methods 400 - 900 described in relation to FIGS. 4 - 9B.

[0122] If it is determined that the target random access procedure is a two - step random access procedure, the process proceeds to block 1102. In block 1102, the terminal device 120 may determine whether a first dedicated random access resource is set for uplink data transmission in the inactive state (i.e., SDT). In some embodiments, the terminal device 120 determines whether the first dedicated random access resource has a size greater than or equal to the size of the buffered content associated with the uplink data, and according to the determination that the first dedicated random access resource has a size greater than or equal to the size of the buffered content, the terminal device 120 may determine that the first dedicated random access resource is set.

[0123] In some embodiments, the terminal device 120 determines whether there is a dedicated resource A having a size equal to the size of the buffered content. According to the determination that the dedicated resource A exists, the terminal device 120 may determine the dedicated resource A as the first dedicated random access resource. According to the determination that the dedicated resource A does not exist, the terminal device may determine whether there is a dedicated resource B having a size larger than the size of the buffered content. According to the determination that the dedicated resource B exists, the terminal device 120 may determine the dedicated resource B as the first dedicated random access resource. According to the determination that the dedicated resource B does not exist, the terminal device 120 may determine that the first dedicated random access resource is not set. This is merely an example, and it should be noted that any other appropriate method can also be implemented to determine whether the first dedicated random access resource is set.

[0124] If it is determined in block 1102 that the first dedicated random access resource is set, in block 1103, the terminal device 120 may determine a preamble, a random access opportunity, and a PUSCH resource from the first dedicated random access resource. If it is determined in block 1102 that the first dedicated random access resource is not set, in block 1104, the terminal device 120 may determine whether the second dedicated random access resource among the random access resources set for uplink data transmission in the non-active state is greater than or equal to the size of the buffered content.

[0125] If it is determined in block 1104 that the second dedicated random access resource is greater than or equal to the size of the buffered content, then in block 1105, the terminal device 120 may determine a preamble, a random access opportunity, and a PUSCH resource from the second dedicated random access resource. If it is determined in block 1104 that the second dedicated random access resource is smaller than the size of the buffered content, then in block 1106, the terminal device 120 may determine whether a random access resource having a PUSCH resource greater than or equal to the size of the buffered content is set.

[0126] If it is determined in block 1106 that a random access resource is set, then in block 1107, the terminal device 120 may determine a preamble, a random access opportunity, and a PUSCH resource from the random access resource. If it is determined in block 1106 that a random access resource is not set, then in block 1108, the terminal device 120 may determine a preamble, a random access opportunity, and a PUSCH resource from a random access resource having the largest size PUSCH resource among the PUSCH resources in the random access resource set for the two-step random access procedure.

[0127] After determining the preamble, the random access opportunity, and the PUSCH resource, in block 1109, the terminal device 120 may transmit the preamble and the uplink data based on the determined random access opportunity and the determined PUSCH resource. In this way, uplink data is transmitted in the inactive state based on the two-step random access procedure.

[0128] If it is determined in block 1101 that the target random access procedure is a 4-step random access procedure, the process may proceed to block 1110 shown in FIG. 11B. In block 1110, the terminal device 120 may determine whether a third dedicated random access resource is set for uplink data transmission in the inactive state. The third dedicated random access resource has a size greater than or equal to the size of the buffered content associated with the uplink data.

[0129] If it is determined in block 1110 that the third dedicated random access resource is set, in block 1111, the terminal device 120 may determine a preamble and a random access opportunity from the third dedicated random access resource. If it is determined in block 1110 that the third dedicated random access resource is not set, in block 1112, the terminal device 120 may determine a preamble and a random access opportunity from the fourth dedicated random access resource having the largest size among the random access resources set for uplink data transmission in the inactive state.

[0130] After determining the preamble and the random access opportunity, in block 1113, the terminal device 120 may transmit the preamble based on the random access opportunity. In block 1114, the terminal device 120 may receive a response to the preamble from the network device. In block 1115, the terminal device 120 may transmit uplink data based on the response. In this way, uplink data is transmitted in the inactive state based on the 4-step random access procedure.

[0131] So far, the initialization of random access considering SDT and resource selection have been described. Next, the control of SDT in the fallback procedure from the 2-step random access procedure to the 4-step random access procedure will be described.

[0132] Fallback Procedure in SDT Based on RACH

[0133] Currently, in the two-step random access procedure, when both four-step and two-step random access resources are configured, the maximum number of transmissions of message A (i.e., msgA-TransMax) is set. If the random access procedure does not complete normally even after transmitting msgA-TransMax times of message A, the terminal device 120 may fallback to the four-step random access procedure and execute the four-step random access procedure. However, if there is no four-step random access resource dedicated to SDT, the current procedure will fail. In view of this point, the embodiments of the present disclosure provide a solution to solve the above problems. This will be described as follows in relation to FIGS. 12 to 14.

[0134] FIG. 12 shows an exemplary method 1200 for switching from a two-step random access procedure to a four-step random access procedure according to some embodiments of the present disclosure. For example, the method 1200 may be executed on the terminal device 120 as shown in FIG. 1. For the purpose of discussion, the method 1200 will be described below with reference to FIG. 1. The method 1200 may include additional blocks not shown and / or may omit some of the shown blocks, and it should be understood that the scope of the present disclosure is not limited in this regard.

[0135] As shown in FIG. 12, in the case where it is determined that the target random access procedure is a two-step random access procedure, in block 1210, the terminal device 120 may determine whether the two-step random access procedure has been executed a predetermined number of times but has not completed normally. In some embodiments, the predetermined number can be determined in any suitable way, and the present disclosure does not limit this.

[0136] If it is determined that the 2-step random access procedure has been executed a predetermined number of times but has not been completed successfully, at block 1220, the terminal device 120 may transmit uplink data based on a 4-step random access procedure. In some embodiments where packet size is considered, at block 1230, the terminal device may determine whether dedicated resources having a size corresponding to the packet size of the uplink data are set for uplink data transmission in the inactive state in the 4-step random access procedure (for example, when transmitting message A). In alternative embodiments where packet size is not considered, the terminal device may determine whether dedicated resources are set regardless of their size for uplink data transmission in the inactive state in the 4-step random access procedure.

[0137] If it is determined at block 1230 that dedicated resources are not set, at block 1240, the terminal device 120 may determine that the target random access procedure has not been completed successfully. Thereby, the random access procedure can be terminated and the failure of the procedure can be avoided.

[0138] FIG. 13 shows another exemplary method 1300 for switching from a 2-step random access procedure to a 4-step random access procedure according to some embodiments of the present disclosure. For example, method 1300 may be executed on the terminal device 120 as shown in FIG. 1. For the purpose of discussion, method 1300 will be described below with reference to FIG. 1. It should be understood that method 1300 may include additional blocks not shown and / or may omit some of the blocks shown, and the scope of the present disclosure is not limited in this regard.

[0139] As shown in FIG. 13, in the case where it is determined that the target random access procedure is a two-step random access procedure, in block 1310, the terminal device 120 may determine whether the two-step random access procedure has been executed a predetermined number of times but has not been successfully completed. In some embodiments, the predetermined number can be determined in any suitable way, and the present disclosure does not impose limitations thereon.

[0140] If it is determined that the two-step random access procedure has been executed a predetermined number of times but has not been successfully completed, the process may proceed to block 1320. In some embodiments where the packet size is considered, in block 1320, the terminal device 120 may determine whether a dedicated resource having a size corresponding to the packet size of the uplink data for the four-step random access procedure is set for uplink data transmission in the inactive state. In alternative embodiments where the packet size is not considered, the terminal device may determine whether the dedicated resource for the four-step random access procedure is set regardless of its size for uplink data transmission in the inactive state.

[0141] If it is determined in block 1320 that the dedicated resource is set, in block 1330, the terminal device 120 may transmit uplink data based on the four-step random access procedure. Thus, the determination as to whether the dedicated resource for the four-step random access procedure is set is made before switching to the four-step random access procedure. Thereby, a more efficient random access procedure for SDT can be realized, and the failure of the procedure can be reliably avoided.

[0142] FIG. 14 shows another exemplary method 1400 for switching from a two-step random access procedure to a four-step random access procedure according to some embodiments of the present disclosure. For example, method 1400 may be executed on terminal device 120 as shown in FIG. 1. For purposes of discussion, method 1400 will be described below with reference to FIG. 1. Method 1400 may include additional blocks not shown and / or may omit some of the blocks shown, and it should be understood that the scope of the present disclosure is not limited in this regard.

[0143] As shown in FIG. 14, in a case where it is determined that the target random access procedure is a two-step random access procedure, at block 1410, terminal device 120 may determine whether a parameter is set. The parameter indicates a predetermined number that is executed when the target random access procedure does not complete normally in a case where the target random access procedure is a two-step random access procedure. In some embodiments, the parameter may be newly defined for SDT. Note that the parameter may be determined by any other suitable method.

[0144] If it is determined at block 1410 that the parameter is set, at block 1420, terminal device 120 may determine whether the target random access procedure (i.e., the two-step random access procedure) has been executed a predetermined number of times but has not completed normally. If it is determined at block 1420 that the two-step random access procedure has been executed a predetermined number of times but has not completed normally, at block 1430, terminal device 120 may transmit uplink data based on a four-step random access procedure. Thereby, the fallback from a two-step to a four-step random access procedure is easily controlled, and the failure of the procedure is surely avoided.

[0145] Embodiments of the present disclosure also provide a communication method implemented in a network device in combination. FIG. 15 shows an exemplary communication method 1500 implemented in a network device according to some embodiments of the present disclosure. For example, method 1500 may be executed on terminal device 110 as shown in FIG. 1. For the purpose of discussion, method 1500 will be described below with reference to FIG. 1. Method 1500 may include additional blocks not shown and / or may omit some of the blocks shown, and it should be understood that the scope of the present disclosure is not limited in this regard.

[0146] As shown in FIG. 15, in block 1510, network device 110 receives uplink data transmitted from inactive terminal device 120 based on a target random access procedure. The target random access procedure is determined based on configuration parameters. The configuration parameters are determined when it is determined that uplink data is transmitted in the inactive state.

[0147] In some embodiments, network device 110 may send information about RACH resources dedicated to uplink data transmission in the inactive state to terminal device 120. In this case, network device 110 may receive uplink data transmitted based on the RACH resources. In some embodiments, the RACH resources are a set of resources, and the resources within the set correspond to different uplink grant sizes.

[0148] In some embodiments, the network device 110 may send information about PUSCH resources dedicated to uplink data transmission in an inactive state during the two-step random access procedure to the terminal device 120. In this case, the network device 110 may receive uplink data transmitted based on the PUSCH resources. In some embodiments, the PUSCH resources are a set of resources, and the resources within the set correspond to different uplink grant sizes.

[0149] In block 1520, the network device 110 sends a response to the terminal device 120 for the reception of uplink data. In some embodiments, the response may include configured grant information for subsequent transmission of uplink data. In some embodiments, the response may indicate to the terminal device 120 to interrupt the configuration for uplink data transmission in the inactive state.

[0150] In some embodiments, the network device 110 may send information about the packet size of uplink data transmission in an inactive state to the terminal device 120. In some embodiments, the information about the packet size may be sent via system information. In some alternative embodiments, the information about the packet size may be configured for the terminal device 120 via an RRC message. Note that such information about the packet size can also be sent to the terminal device 120 in any other suitable way.

[0151] In some embodiments, the packet size may be associated with at least one of the access category, access identity, QoS parameter, and data radio bearer of the uplink data.

[0152] Both the 2-step random access procedure and the 4-step random access procedure are set. In the 4-step random access procedure, dedicated resources having a size corresponding to the packet size of uplink data are set for uplink data transmission in the inactive state. In some embodiments, the network device 110 may set a parameter indicating a predetermined number that is executed when the target random access procedure does not complete normally in the case where the target random access procedure is the 2-step random access procedure. Thereby, the fallback from the 2-step to the 4-step random access procedure is easily controlled, and the failure of the procedure is surely avoided.

[0153] FIG. 16 is a schematic block diagram of a device 1600 suitable for implementing an embodiment of the present disclosure. The device 1600 can be regarded as another exemplary implementation of the network device 110 or the terminal device 120 shown in FIG. 1. Therefore, the device 1600 can be implemented in or as at least a part of the network device 110 or the terminal device 120.

[0154] As shown in the figure, device 1600 includes a processor 1610, a memory 1620 coupled to the processor 1610, a suitable transmitter (TX) and receiver (RX) 1640 coupled to the processor 1610, and a communication interface connected to the TX / RX 1640. The memory 1610 stores at least a part of the program 1630. The TX / RX 1640 is for bidirectional communication. The TX / RX 1640 has at least one antenna for facilitating communication, but in fact, the access node described in this application may have multiple antennas. The communication interface may represent any interface required for communicating with other network elements, for example, the X2 / Xn interface for bidirectional communication between eNBs / gNBs, the S1 / NG interface for communication between a mobility management entity (MME) / access and mobility management function (AMF) / SGW / UPF and an eNB / gNB, the Un interface for communication between an eNB / gNB and a relay node (RN), or the Uu interface for communication between an eNB / gNB and a terminal device.

[0155] Assuming that the program 1630 includes program instructions, as discussed with reference to FIGS. 1-15 herein, these program instructions are executed by the associated processor 1610. Thereby, the device 1600 can be made to operate based on the embodiments of the present disclosure. The embodiments herein may be implemented by computer software, hardware, or a combination of software and hardware executable by the processor 1610 of the device 1600. The processor 1610 may be arranged to implement each embodiment of the present disclosure. Also, the combination of the processor 1610 and the memory 1620 may constitute a processing means 1650 suitable for implementing each embodiment of the present disclosure.

[0156] Memory 1620 may be of any type suitable for a local technology network and may be implemented by any suitable data storage technology (examples include, but are not limited to, computer-readable non-transitory storage media, semiconductor-based storage devices, magnetic storage devices and systems, optical storage devices and systems, fixed memory, and removable memory, etc.). Although only one memory 1620 is shown for device 1600, a plurality of physically different memory modules may be installed in device 1600. Processor 1610 may be of any type suitable for a local technology network and may include, for example, but is not limited to, a general-purpose computer, a dedicated computer, a microprocessor, a digital signal processor (DSP), and one or more of processors based on a multi-core processor configuration. Device 1600 may have a plurality of processors, for example, application-specific integrated circuit chips that are temporally dependent on a clock synchronized with a master processor.

[0157] Generally, each embodiment of the present disclosure may be implemented by hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects may be implemented by hardware, and other aspects may be implemented by firmware or software that can be executed by a controller, a microprocessor, or other computing devices. Each aspect of the embodiments of the present disclosure is illustrated and described as a block diagram, a flowchart, or shown by some other pictorial representation. It should be understood that the blocks, devices, systems, technologies, or methods described herein may be implemented, for example, by hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or a controller or other computing device, or a combination thereof, but are not limited thereto.

[0158] The present disclosure further provides at least one computer program product tangibly stored on a computer-readable non-transitory storage medium. The computer program product includes computer-executable instructions, such as instructions included in program modules. The instructions are executed on a device on a target physical processor or virtual processor, and perform, for example, the processes or methods described above with reference to FIGS. 2 to 15. Usually, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In each embodiment, the functions of the program modules may be combined or divided among the program modules as needed. The machine-readable instructions of the program modules may be executed on a local or distributed device. In a distributed device, the program modules may be located on either a local or a remote storage medium.

[0159] The program code for implementing the method of the present disclosure may be described by any combination of one or more programming languages. The program code may be provided to a processor or a controller of a general-purpose computer, a dedicated computer, or other programmable data processing device. When the program code is executed by the processor or the controller, the functions / operations defined in the flowchart and / or the block diagram are implemented. The program code may 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.

[0160] The above program code may be embodied on a machine-readable medium. The machine-readable medium can be any tangible medium that includes or stores a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium can 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 foregoing. More specific examples of the machine-readable storage medium include one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0161] Note that although the operations have been described in a particular order, it should not be understood that such operations must be performed in the particular order shown or sequentially in order to obtain a desired result, and all of the operations shown may not be required in some situations. In some circumstances, multitasking and parallel processing may be advantageous. Similarly, while the above discussion includes some specific implementation details, these are not limitations on the scope of the present disclosure and should be construed as descriptions of features specific to particular embodiments. Some features described in the context of individual embodiments may be implemented in combination in one embodiment. Conversely, various features described in the context of one embodiment may be implemented separately in a plurality of embodiments or in any suitable sub-combination.

[0162] Although the present disclosure has been described in terms of language specific to structural features and / or methodological acts, it is to be understood that the disclosure defined by the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as illustrative forms of implementing the claims.

Claims

1. Determining whether the size of uplink data including data and signaling is less than or equal to a threshold value; indicating to an upper layer by a Media Access Control (MAC) layer that small data transmission (SDT) is not executed in response to determining that the size of the uplink data including data and signaling is greater than the threshold value; executing a selection of an uplink carrier from a normal uplink carrier and an additional uplink carrier to transmit the uplink data including data and signaling in a non-active state in an SDT procedure in response to determining that the size of the uplink data including data and signaling is less than or equal to the threshold value; starting the SDT procedure in response to using a random access resource for the SDT procedure on the selected uplink carrier; A method performed by a terminal device, including the above steps.

2. The random access resource for the SDT procedure is at least one of a two-step random access resource and a four-step random access resource. The method according to Claim 1.

3. Means for determining whether the size of uplink data including data and signaling is less than or equal to a threshold value; means for indicating to an upper layer by a Media Access Control (MAC) layer that small data transmission (SDT) is not executed in response to determining that the size of the uplink data including data and signaling is greater than the threshold value; means for executing a selection of an uplink carrier from a normal uplink carrier and an additional uplink carrier to transmit the uplink data including data and signaling in a non-active state in an SDT procedure in response to determining that the size of the uplink data including data and signaling is less than or equal to the threshold value; means for starting the SDT procedure in response to using a random access resource for the SDT procedure on the selected uplink carrier; A terminal device comprising the above means.

4. The random access resource for the SDT procedure is at least one of a two-step random access resource and a four-step random access resource. The terminal device according to Claim 3.

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