Data transmission method, electronic device, and storage medium

Abstract

The present application relates to but is not limited to the technical field of communications, and provides a data transmission method, an electronic device, and a storage medium. The data transmission method comprises: a user equipment (UE) and a radio access network (RAN) node carry out bottom layer signaling transmission carrying a non-access stratum protocol data unit (NAS PDU).

Description

Data transmission method, electronic device and storage medium

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202311282217.1 and application date September 28, 2023, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The embodiments of the present application relate to, but are not limited to, the field of communication technologies, and in particular to a data transmission method, an electronic device, and a storage medium. Background Art

[0004] With the development of wireless communication technology, a communication system needs to support an increasing number of users and devices simultaneously. In practical applications, there are scenarios where small data transmission occurs between users and devices, and as small data transmission increases, the load on the communication system increases accordingly. Although different solutions have been proposed in related technologies for small data transmission to balance the load of the communication system, such as the use of pre-configured uplink resources (PUR) or early data transmission (EDT) in narrowband Internet of Things (NB-IoT) and enhanced machine-type communication (eMTC) for small data transmission, both PUR and EDT can only transmit one uplink or downlink data packet at a time. In the New Radio (NR) system, although configured grants (CG) and random access (RA) are also used for small data transmission, they involve radio resource control (RRC) messages. Therefore, in related technologies, small data transmission technology still suffers from low transmission efficiency.

[0005] Summary of the Invention

[0006] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0007] In a first aspect, an embodiment of the present application provides a data transmission method, which is applied to a user equipment (UE) and includes the steps of transmitting underlying signaling carrying a non-access stratum protocol data unit (NAS PDU) with a radio access network (RAN) node.

[0008] In a second aspect, an embodiment of the present application provides a data transmission method. The method is applied to a radio access network RAN ​​node and includes the steps of transmitting underlying signaling carrying a non-access layer protocol data unit NAS PDU with a user equipment UE.

[0009] In a third aspect, embodiments of the present application further provide an electronic device. The electronic device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the data transmission method described in the first aspect or the data transmission method described in the second aspect is implemented.

[0010] In a third aspect, embodiments of the present application further provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method according to the first aspect or the method according to the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG1 is a schematic diagram of underlying signaling interaction in an embodiment of a data transmission method provided by the present application applied to a communication system;

[0012] FIG2 is a schematic diagram of NAS PDU interaction in another embodiment of the data transmission method provided by the present application applied to a communication system;

[0013] FIG3 is a schematic diagram of underlying signaling interaction in another embodiment of the data transmission method provided by the present application applied to a communication system;

[0014] FIG4 is a flow chart of a data transmission method applied to a UE provided in the present application;

[0015] FIG5 is a schematic diagram of the structure of a MAC CE in an embodiment of the data transmission method provided by the present application;

[0016] FIG6 is a schematic diagram of the structure of a MAC CE in another embodiment of the data transmission method provided by the present application;

[0017] FIG7 a is an interactive diagram of the MO process of the first embodiment of the data transmission method provided by the present application;

[0018] FIG7 b is an interactive diagram of the MO process of the second embodiment of the data transmission method provided by the present application;

[0019] FIG7 c is an interactive diagram of the MT process of the first embodiment of the data transmission method provided by the present application;

[0020] FIG7 d is an interactive diagram of the MT process of the second embodiment of the data transmission method provided by the present application;

[0021] FIG8 is a schematic diagram of the interaction of the NAS cryptographic key negotiation process in the data transmission method provided by the present application;

[0022] FIG9a is a schematic diagram of interaction for SR or BSR transmission using pre-configured resources in a UE energy-saving state in the data transmission method provided by the present application;

[0023] FIG9 b is a schematic diagram of interaction for small data transmission using pre-configured resources in a UE energy-saving state in the data transmission method provided by the present application;

[0024] FIG10 is a flow chart of a data transmission method applied to a RAN node provided in the present application; and

[0025] FIG11 is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0027] It should be noted that although the device schematics illustrate functional module divisions and the flowcharts illustrate logical sequences, in certain circumstances, the steps shown or described may be performed in a sequence that differs from the module divisions in the device or the sequence in the flowcharts. The terms "first," "second," and so on, in the specification, claims, and drawings, are used to distinguish similar items and are not necessarily used to describe a specific sequence or precedence.

[0028] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0029] The following are the Chinese and English definitions of the terms involved in the embodiments of this application:

[0030] Non-access layer, also known as non-access-stratum, referred to as NAS.

[0031] Protocol data unit, also known as protocol data unit, abbreviated as PDU.

[0032] Media access control-control element, namely media access control-control element, referred to as MAC CE.

[0033] Core network node, namely CoreNetwork, referred to as CN.

[0034] Base station, that is, base station.

[0035] Specific search space, namely UE specific search space, referred to as USS.

[0036] Buffer Status Report, also known as Buffer Status Report, abbreviated as BSR.

[0037] Radio Network Temporary Identifier, or RNTI.

[0038] Media Access Control Service Data Unit, or MAC SDU.

[0039] Tracking area update, also known as tracking area updata, referred to as TAU.

[0040] Scheduling Request, Scheduling Request, referred to as SR.

[0041] Contention Free Random Access, also known as Contention Free Random Access; abbreviated as CFRA.

[0042] Physical uplink control channel, namely PUCCH.

[0043] Physical uplink shared channel, namely PUSCH.

[0044] It should be noted that with the development of wireless communication technology, a communication system needs to simultaneously support an increasing number of users and devices. In actual applications, there are scenarios where small data transmission occurs between users and devices, and as small data transmission increases, the load on the communication system increases accordingly. In particular, in 6G scenarios, more users and devices are allowed to be supported than in existing wireless communication systems. Although communication systems in related technologies have proposed different solutions for small data transmission to balance the load of the communication system, such as the narrowband Internet of Things (NB-IoT) and enhanced machine-type communication (eMTC), which use pre-configured uplink resources (PUR) or early data transmission (EDT) for small data transmission, PUR and EDT involve Radio Resource Control (RRC) protocol negotiation during the transmission process. In EDT, when the RRC is in the idle state, the terminal device briefly enters the connected state and then immediately enters the idle state, thereby achieving small data transmission. At this time, the RRC connection is not actually established. At the same time, PUR can only transmit fixed-size data at a fixed period. Moreover, both PUR and EDT can only transmit one uplink data packet or downlink data packet at a time; and in the New Radio (NR) system, although there is also an RRC_INAACTIVE state that uses a configured grant (CG) and random access (RA) to transmit small data, it also involves RRC messages, and the small data transmission using the CG method can only be transmitted in a fixed period and with a fixed amount of data. Therefore, in the related art, the small data transmission technology still has the problem of low transmission efficiency. Based on this, the present application provides a data transmission method, an electronic device, and a storage medium that can solve the problem of low transmission efficiency of the small data transmission technology.

[0045] It should be noted that the data transmission method of the present application is applied to the communication system as shown in Figure 1, wherein the communication system includes at least two interacting entities, and the interaction between the two entities carries the underlying signaling of NAS PDU.

[0046] Figure 1 illustrates the process of transmitting NAS PDUs and NAS UE identities between entities 1 and 2, where entities 1 and 2 can be different entities within the UE (e.g., the MAC layer and the PDCP layer), or they can be different entities on the network side (e.g., the MAC layer and the PDCP layer, or the base station centralized unit (CU) and the base station distributed unit (DU), or the base station and the core network). For example, taking the example of both entities shown in Figure 2 being RAN nodes, where both entities 1 and 2 are RAN nodes (e.g., the two RAN nodes are gNB-CU / gNB-DU, or gNB / CN), namely RAN node 1 and RAN node 2, respectively, NAS PDUs are transmitted between RAN node 1 and RAN node 2 via control plane signaling or user plane bearer. For another example, taking the example of the two entities shown in Figure 3 being a UE and a base station, NAS PDUs are transmitted between the UE and the base station via underlying signaling carrying NAS PDUs. MAC layer transmission can be achieved by carrying NAS PDUs via a MAC CE or an SRB.

[0047] It should be noted that the communication network can be divided into L1 (physical layer), L2 (data link layer) and L3 (network layer), among which the MAC layer, RLC, PDCP and RRC are all located in the data link layer, and the underlying signaling is the signaling that can be transparently transmitted and is located in the link transport layer, such as the underlying signaling is MAC CE. In some embodiments, the underlying signaling is an independent SRB or the protocol defines a default SRB specifically for carrying NAS PDU; in this case, the underlying signaling does not require PDCP processing or does not pass through PDCP, and there is no RLC processing or RLC adopts TM mode, but only transparently transmits NAS PDU. For example, referring to Figures 1 and 2, taking the underlying instruction transmission between the MAC layer in the base station and the UE as an example, the downlink NAS PDU is transmitted from the RRC layer / PDCP layer to the MAC layer, or the uplink NAS PDU is transmitted from the MAC layer to the RRC layer / PDCP layer; that is, the NAS PDU interacts in the MAC CE, rather than being transmitted through the characteristic signaling of the UE. Similarly, for the UE, the downlink NAS PDU and / or NAS UE identifier is passed from the MAC layer to the RRC layer / PDCP layer, or the uplink NAS PDU and / or NAS UE identifier is passed from the RRC layer / PDCP layer to the MAC layer. In this case, the NAS PDU and the like interact directly at the MAC layer, rather than through specific signaling transmission of the UE. It should be noted that, in some embodiments, when the NAS PDU involves data processing, such as encryption, the NAS PDU is encrypted by the NAS entity (wherein the NAS entity is such as a network node in the CN or the UE NAS layer).

[0048] Therefore, by carrying NAS PDU in the underlying signaling, the NAS PDU can be transparently transmitted in the data link layer with the help of the underlying signaling, and there is no need to perform wireless link-related operations such as establishment, release, maintenance and reconfiguration, thereby making the transmission process simpler and able to transmit more data, and there is no need for a fixed period requirement. Therefore, compared with related technologies, the embodiments of the present application can solve the problem of low transmission efficiency of small data transmission technology.

[0049] 4 , a data transmission method according to the first aspect of the present application includes the following steps:

[0050] Step S100: The UE performs underlying signaling transmission with a radio access network RAN ​​node carrying a non-access stratum protocol data unit (NAS PDU).

[0051] Therefore, by carrying NAS PDU in the underlying signaling, the NAS PDU can be transparently transmitted in the data link layer with the help of the underlying signaling, and there is no need to perform wireless link-related operations such as establishment, release, maintenance and reconfiguration, thereby making the transmission process simpler and able to transmit more data, and there is no need for a fixed period requirement. Therefore, compared with related technologies, the embodiments of the present application can solve the problem of low transmission efficiency of small data transmission technology.

[0052] It should be noted that the RAN node may be a base station, a CU of a base station, a DU of a base station, or a CN, etc.

[0053] It should be noted that, in some embodiments, the underlying signaling is a MAC CE, which is a MAC CE of variable size and contains at least one NAS PDU. When it is a downlink MAC CE, its NAS PDU can come from the CN. When it is an uplink MAC CE, its NAS PDU comes from the UE. As shown in FIG5 , a MAC CE contains a NAS PDU that occupies m bytes in length, wherein Oct1 is the first byte occupied by the corresponding NAS PDU, Oct2 is the second byte occupied by the corresponding NAS PDU (Cont.), ..., Octm is the mth byte occupied by the corresponding NAS PDU (Cont.); m is a positive integer, and the value can be selectively set according to actual needs. In other embodiments, the underlying signaling is an SRB, in which case the SRB is used to carry the NAS PDU and transparently transmit the NAS PDU.

[0054] It is understood that the underlying signaling transmission with the RAN node carrying the Non-Access Stratum Protocol Data Unit (NAS PDU) includes:

[0055] Sending uplink underlying signaling carrying non-access stratum protocol data units (NAS PDUs) to the RAN node;

[0056] and / or,

[0057] Receive downlink underlying signaling carrying NAS PDU sent by the RAN node.

[0058] For example, as shown in FIG1 , when entity 1 is a UE, entity 2 is a RAN node, so that the UE receives downlink underlying signaling sent by the RAN node; when entity 1 is a RAN node and entity 2 is a UE, the UE sends uplink underlying signaling to the RAN node; thereby, bidirectional interaction of underlying signaling between the two entities can be achieved.

[0059] For example, as shown in Figure 2, when RAN node 1 is the CU of a base station and RAN node 2 is the DU of the base station, a downlink NAS PDU is sent from the CU to the DU to deliver downlink underlying signaling carrying the NAS PDU to the UE; an uplink NAS PDU is sent from the DU to the CU to pass the non-access stratum protocol data unit (NAS PDU) received in the uplink underlying signaling from the UE to higher layers. When RAN node 1 is the CN, a downlink NAS PDU is sent from the CN to the base station (i.e., RAN node 2) to deliver downlink underlying signaling carrying the NAS PDU to the UE; an uplink NAS PDU is sent from the base station to the CN to pass the non-access stratum protocol data unit (NAS PDU) received in the uplink underlying signaling from the UE to higher layers. The NAS PDU can be included in UE-specific signaling between the base station and the CN or included in a user plane PDU (e.g., identified by a specific GTP-U channel or using a specific GTP-U header).

[0060] It is understood that the underlying signaling transmission with the RAN node carrying the Non-Access Stratum Protocol Data Unit (NAS PDU) includes:

[0061] Sending a first uplink bottom layer signaling carrying a first NAS UE identifier to the RAN node;

[0062] receiving a first downlink underlying signaling sent by the RAN node and carrying a second NAS UE identifier;

[0063] When the first NAS UE identifier and the second NAS UE identifier match, a second uplink underlying signaling carrying the NAS PDU is sent to the RAN node and / or a second downlink underlying signaling carrying the NAS PDU sent by the RAN node is received until a preset condition is met.

[0064] It should be noted that in some embodiments, a NAS UE identity is exchanged through underlying signaling to identify the device information of a ready sender or specific sender information. For example, taking the interaction between a RAN node and a UE as an example, a first NAS UE identity is sent to the RAN to inform the RAN node that the second underlying signaling to be sent next is for the UE corresponding to the first NAS UE identity. Accordingly, the RAN node uses the second NAS UE identity to inform the UE that it is ready to receive the underlying signaling. For example, as shown in FIG6 , before the first MAC CE transmission carrying a NAS PDU or when the UE receives a message indicating a downlink NAS PDU transmission, the UE first transmits uplink underlying signaling carrying the first NAS UE identity. For example, if the length of the first NAS UE identity is N bytes, as shown in FIG6 , N bytes are allocated in the MAC CE to store the first NAS UE identity. Here, Oct1 is the first byte of the UE NAS Identity, Oct2 is the second byte of the UE NAS Identity, ..., and Oct N is the Nth byte of the UE NAS Identity. N can be set selectively based on actual needs.

[0065] It should be noted that the preset condition is the condition for stopping the interaction of the underlying instructions, which can be set to a fixed time interval, etc., and those skilled in the art can selectively set it according to actual needs.

[0066] It is understandable that whether the first NAS UE identifier and the second NAS UE identifier match is determined by one of the following steps:

[0067] If the first NAS UE identifier is the same as the second NAS UE identifier, it is determined that the first NAS UE identifier and the second NAS UE identifier match;

[0068] or,

[0069] If the second NAS UE identifier is identical to the segment in the first NAS UE identifier, it is determined that the first NAS UE identifier and the second NAS UE identifier match.

[0070] It should be noted that by using the matching condition that the first NAS UE identifier is identical to the second NAS UE identifier, strong verification can be performed to enhance security. By using the matching condition that the second NAS UE identifier is identical to the fragment in the first NAS UE identifier, verification efficiency can be improved.

[0071] For example, the second NAS UE identifier is the minimum M bits or the rightmost M bits of the first NAS UE identifier that can be used to determine whether the NAS UE identifier matches, where M is an integer.

[0072] It is understandable that the first uplink bottom layer signaling carries NAS PDU.

[0073] It should be noted that, as shown in FIG1 and FIG3 , the NAS PDU and the first NAS UE identifier may be transmitted in the same underlying signaling.

[0074] It is understandable that the first uplink bottom layer signaling includes one or more uplink bottom layer signalings;

[0075] The NAS PDU and the first NAS UE identity are carried by one uplink bottom layer signaling, or the NAS PDU and the first NAS UE identity are carried by different uplink bottom layer signaling.

[0076] It should be noted that, as shown in Figures 1 and 3 , the NAS PDU and the first NAS UE identity may also be transmitted in two different MAC CEs, and the two MAC CEs are transmitted to the RAN node simultaneously.

[0077] It should be noted that each uplink bottom layer signaling corresponds to a MAC CE.

[0078] It is understandable that the first downlink bottom layer signaling carries NAS PDU.

[0079] It should be noted that, as shown in Figures 1 and 2, the NAS PDU and the second NAS UE identity can be transmitted in the same MAC CE. In this case, the first downlink underlying signaling carries the NAS PDU.

[0080] It is understandable that the first downlink bottom layer signaling includes one or more downlink bottom layer signaling;

[0081] The NAS PDU and the second NAS UE identity are carried by one downlink underlying signaling, or the NAS PDU and the first NAS UE identity are carried by different downlink underlying signaling.

[0082] It should be noted that, as shown in Figures 1 and 3, the NAS PDU and the second NAS UE identifier can be transmitted in different MAC CEs. In this case, the first downlink underlying signaling includes multiple downlink underlying instructions, at least one downlink underlying instruction carries the NAS PDU, and one downlink underlying instruction carries the second NAS UE identifier.

[0083] It is understood that the preset conditions include: the timer timing exceeds the deadline;

[0084] The timing starting point or re-timing starting point of the timer is: the UE sends a NAS PDU, or the UE receives a NAS PDU, or the UE receives an uplink grant, or the UE receives a downlink grant.

[0085] In some embodiments, the timer is configured by the RAN node.

[0086] It is understandable that the preset condition includes: receiving a data transmission completion indication sent by a RAN node.

[0087] It should be noted that, when the RAN node determines that the MAC CE interaction needs to be stopped, it will send a data transmission completion indication to the UE to inform the UE that the transmission is completed.

[0088] It should be noted that, in some embodiments, before receiving the data transmission completion indication sent by the RAN node, a no uplink data indication (for example, reporting a buffer size of 0) is also received from the RAN node.

[0089] It is understandable that, before sending the first uplink underlying signaling carrying the first NAS UE identifier to the RAN node, the method further includes:

[0090] Sending a preamble message to the RAN node;

[0091] receiving a response message sent by the RAN node in response to the preamble message, wherein the response message is used to instruct the UE to send first uplink lower layer signaling carrying the first NAS UE identifier, and / or is used to instruct the RAN node to allocate resources to the UE for sending the first uplink lower layer signaling carrying the first NAS UE identifier in response to the preamble message.

[0092] It should be noted that, referring to Figures 7a to 7d, taking the RAN node as a base station as an example, the UE sends a preamble message to the RAN node, and the base station sends a response message corresponding to the preamble message to the UE, thereby implementing the access process.

[0093] It is understandable that, before sending the preamble message to the RAN node, the method further includes:

[0094] A random access preamble transmission indication message or a paging message carrying a random access preamble transmission indication sent by a RAN node is received, where the random access preamble transmission indication message or the paging message carrying the preamble transmission indication is used to instruct the UE to send a preamble message.

[0095] It should be noted that, referring to Figures 7b to 7d, in some scenarios, as shown in Figure 7b, before sending a preamble message (corresponding to "MsgA" in Figure 7b) to the RAN node, a preamble transmission indication message sent by the RAN node is received. In other embodiments, as shown in Figures 7c and 7d, before sending a preamble message to the RAN node (where the preamble message in Figure 7c includes a "random access preamble" and a "first NAS identity MAC CE"; the preamble message in Figure 7d is "MsgA"), a paging message carrying a preamble transmission indication is received from the RAN node.

[0096] It is understood that the leading message includes at least one of the following:

[0097] Random access preamble;

[0098] Uplink underlying signaling carrying NAS PDU;

[0099] Uplink underlying signaling carrying the first NAS UE identity.

[0100] Exemplarily, as shown in Figure 7a, in some embodiments, taking the RAN node as a base station as an example, the UE sends a random access preamble code to the base station; and according to the random access response message fed back by the base station, the UE sends the corresponding uplink underlying signaling to the base station (i.e., the uplink NAS PDU MAC CE and the first NAS UE identity MAC CE in Figure 7a), thereby completing the sending of the preamble message; wherein, the uplink NAS PDU MAC CE is the underlying signaling carrying the NAS PDU; the first NAS UE identity MAC CE is the underlying signaling carrying the first NAS UE identity.

[0101] It should be noted that the random access preamble, the uplink underlying signaling carrying the NAS PDU, and the uplink underlying signaling carrying the first NAS UE identifier can be respectively carried and transmitted by one MAC CE. In some embodiments, the NAS PDU and the first NAS UE identifier can also be carried and transmitted by one MAC CE.

[0102] It should be noted that the preamble is a non-mandatory parameter in the preamble message and can be selectively set according to actual needs or determined by negotiation between the RAN node and the UE. The preamble message can also include uplink underlying signaling carrying the NAS PDU and uplink underlying signaling carrying the first NAS UE identifier. In some embodiments, the preamble message does not include uplink underlying signaling carrying the NAS PDU.

[0103] It is understood that the response message includes at least one of the following:

[0104] Random access response information;

[0105] Downlink underlying signaling carrying NAS PDU;

[0106] Downlink underlying signaling carrying the second NAS UE identifier.

[0107] It should be noted that if the UE does not send a preamble, a response message is not required. When the UE's preamble message does not include the uplink underlying signaling of the NAS PDU, the response message does not include the downlink signaling instructions of the NAS PDU.

[0108] For example, as shown in FIG7a , in some embodiments, taking the RAN node as a base station, the UE sends a random access preamble to the base station; the base station feeds back random access response information to the UE, the UE sends uplink lower layer signaling carrying a first NAS UE identifier to the base station (i.e., the "first NAS UE identifier MAC CE" in FIG7a ), and the base station returns downlink lower layer signaling carrying a NAS PDU to the UE (i.e., the "downlink NAS PDU MAC CE and / or the second NAS UE identifier MAC CE" in FIG7a ). At this point, the UE completes sending the preamble message to the RAN node; the base station completes receiving the response message sent by the RAN node based on the preamble message. In other embodiments, after successfully completing the random access procedure, as shown in FIG7a - FIG7d , the UE continues to send uplink lower layer signaling to the base station (i.e., the "uplink NAS PDU MAC CE" in FIG7a - FIG7d ) and continues to receive downlink lower layer signaling from the base station (i.e., the "downlink NAS PDU MAC CE" in FIG7a - FIG7d ) until no downlink lower layer signaling is received or no uplink lower layer signaling transmission is required.

[0109] It should be noted that in the MsgA and MsgB shown in Figures 7b and 7d, MsgA includes at least a MAC CE carrying the first NAS UE identifier, which can be an S-TMSI. If an uplink NAS PDU needs to be transmitted, MsgA also includes a MAC CE carrying the NAS PDU. In some embodiments, if a random access preamble needs to be sent, MsgA also includes a MAC CE corresponding to the random access preamble. For the UE, the NAS PDU and the first NAS UE can be transmitted to the base station using the same MAC CE, or they can be carried in different MAC CEs and transmitted to the base station. Similarly, for MsgB, MsgB includes at least a MAC CE carrying the second NAS UE identifier. When the MsgA sent by the UE includes a random access preamble, MsgB also includes a random access response message. In some embodiments, MsgB also includes a MAC CE carrying the NAS PDU. At this time, for the base station, the NAS PDU and the second NAS UE identifier can be transmitted to the UE by the same MAC CE, or can be transmitted to the UE by two different MAC CEs.

[0110] Exemplarily, as shown in FIG7b , the base station sends a preamble transmission indication message to the UE to indicate whether the cell where the UE is located needs to transmit a preamble message. The UE sends a preamble message (corresponding to "MsgA") to the base station. After receiving the preamble message, the base station sends a response message (corresponding to "MsgB") to the UE. After receiving the response message, the UE sends an uplink underlying signaling to the base station (corresponding to the "uplink NAS PDU MAC CE and / or the first NAS UE identification MAC CE" in the figure). The base station receives the uplink underlying signaling and sends a downlink underlying signaling to the UE (corresponding to the "downlink NAS PDU MAC CE and / or the second NAS UE identification MAC CE" in the figure) to enable the UE to determine whether the random access process is completed. Whether the preamble message includes a random access preamble can be confirmed based on a preamble transmission indication message. The basis for setting the random access preamble can be selectively set based on actual needs. For example, the base station determines whether a random access preamble is required based on the PUSCH CP length and cell coverage. For example, when the cell coverage is less than 200 km, the RTT between the UE and the base station is less than a TA (Timing Advance) granularity of a 15 kHz SCS. If the cell coverage is less than 200 km and the cell is configured with a 15 kHz SCS, a random access preamble is not required. It should be noted that in some embodiments, a preamble transmission indication message is also set via OAM. In some embodiments, when the base station does not indicate that random access preamble transmission is not required, the preamble message also includes a random access preamble. That is, in some embodiments, the preamble message includes a random access preamble and a first NAS UE identifier; or a random access preamble, a first NAS UE identifier, and a NAS PDU; or uplink bottom layer signaling consisting of the random access preamble and the first NAS UE identifier and another uplink bottom layer signaling consisting of a NAS PDU. Accordingly, the response message is set with reference to the preamble information. In this regard, the embodiments of the present application will not be described in detail. It should be noted that, as shown in Figure 7b, when the UE receives the "downlink NAS PDU MAC CE and / or second NAS UE identification MAC CE" from the base station (i.e., corresponding to Figure 7b, after the base station performs the third step of sending downlink underlying signaling to the UE), it means that the UE confirms that the NAS access is successful, and at this time, the NAS PDU can be exchanged normally between the UE and the base station.

[0111] It should be noted that, as shown in Figure 7b, after the random access is confirmed to be successful between the UE and the base station, the UE can continue to receive downlink bottom layer instructions carrying NAS PDU, or transmit uplink bottom layer instructions carrying NAS PDU. The UE can decide whether to continue to send uplink bottom layer signaling or receive downlink bottom layer signaling based on the timer set in the preset conditions or the indication of data transmission completion sent by the base station. In some embodiments, the timer is configured by the base station, and the timer is started or restarted when the base station confirms that the UE has sent an uplink NAS PDU or the UE has received a downlink NAS PDU. Alternatively, the timer is started or restarted when the UE confirms that it has received a PDCCH carrying an uplink authorization or a downlink authorization after receiving a response message. For example, the UE does not start or restart the timer when transmitting a preamble or receiving a response message.

[0112] It should be noted that, for the first NAS UE identifier and the second NAS UE identifier in Figure 7b, in some embodiments, the first NAS UE identifier and the second NAS UE identifier are the same, and in other embodiments, the second NAS UE identifier is a truncated portion of the first NAS UE identifier, such as the truncated portion is the M bits of the first NAS UE identifier that are the minimum number of bits used for identification, or the rightmost M bits of data, where M is an integer.

[0113] For example, referring to FIG7c, taking an application scenario in which downlink underlying signaling is transmitted to a base station through a CN and then the base station sends downlink underlying signaling to a UE as an example, the CN sends a paging message with a NAS PDU to the base station, wherein the NAS PDU transmission indication may be a NAS encryption indication so as to encrypt the NAS PDU and enable the UE to identify whether it can be transmitted through the underlying signaling. The base station then sends a paging message to the UE, the UE sends a preamble to the base station, the base station sends a response message corresponding to the preamble to the UE, and after receiving the response message, the UE sends a MAC CE corresponding to the first NAS UE identifier (such as an S-TMSI) to the base station. In some scenarios (such as when there are sufficient uplink resources to carry both the first NAS identifier and the NAS PDU), the NAS PDU is also carried in the same MAC CE. Accordingly, the base station sends downlink lower layer signaling to the UE, where the downlink lower layer signaling carries at least a second NAS UE identifier, wherein the first NAS UE identifier and the second NAS UE identifier are the same. In other embodiments, the second NAS UE identifier is a truncated portion of the first NAS UE identifier, such as the M bits of the first NAS UE identifier that are the minimum number of bits used for identification, or the rightmost M bits, where M is an integer. In some embodiments, the downlink lower layer signaling also carries a NAS PDU. When the UE successfully matches the second NAS UE identifier with the first NAS UE ID, the MT process is successful. After the UE and the base station confirm that the MT process is successful, the UE may continue to receive downlink lower layer commands carrying NAS PDUs or transmit uplink lower layer commands carrying NAS PDUs. The UE may determine whether to continue sending uplink lower layer signaling or receiving downlink lower layer signaling based on a timer set in a preset condition or an indication of data transmission completion sent by the base station. In some embodiments, the timer is configured by the base station and is started or restarted when the base station confirms that the UE has sent an uplink NAS PDU or the UE has received a downlink NAS PDU. Or the timer is started or restarted when the UE confirms that it has received a PDCCH carrying an uplink authorization or a downlink authorization after receiving a response message. For example, the timer is not started or restarted when the UE transmits a preamble or receives a response message.

[0114] It should be noted that, in some embodiments, the paging message does not contain a NAS PDU transmission indication, but the UE already has the information contained in the NAS PDU transmission indication. For example, taking the NAS PDU transmission indication as a NAS cryptographic key as an example, when the UE already has a NAS cryptographic key, the UE will directly send an uplink underlying instruction after receiving the paging message from the base station. At this time, the uplink underlying instruction may include a first NAS UE identifier, or include a first NAS UE identifier and a NAS PDU.

[0115] For example, as shown in Figure 7d, taking the case where a two-step random access channel (RACH) is used to transmit MAC CE during the MT negotiation process and the NAS PDU transmission indication is a NAS password as an example, when the CN sends a paging message carrying the NAS PDU to the base station, the base station sends a paging message with the NAS PDU to the UE.

[0116] It is understandable that the random access preamble transmission indication message or the paging message carrying the random access preamble transmission indication carries the NAS cryptographic key, wherein the NAS cryptographic key is used to encrypt the NAS PDU and / or implicitly indicate whether the UE is allowed to send uplink underlying signaling carrying the NAS PDU, or the authority or capability to send uplink underlying signaling carrying the NAS PDU.

[0117] It is understandable that, before performing underlying signaling transmission with the RAN node carrying the non-access stratum protocol data unit NAS PDU, the method further includes:

[0118] Perform NAS cryptographic key negotiation with the core network node to obtain whether to allow the sending of uplink underlying signaling carrying NAS PDU, or the authority or capability to send uplink underlying signaling carrying NAS PDU.

[0119] It is understood that the method further comprises:

[0120] Renegotiate the NAS cryptographic key with the core network node through the Tracking Area Update (TAU) procedure;

[0121] or,

[0122] Obtain updated NAS cryptographic keys from the core network node through the TAU process;

[0123] or,

[0124] Renegotiate NAS cryptographic keys with the core network node via NAS PDU;

[0125] or,

[0126] Obtain updated NAS cryptographic keys from the core network node via NAS PDU.

[0127] For example, as shown in FIG8 , the UE and the CN negotiate a NAS cryptographic key during an initial attach procedure or a registration procedure. The UE and the CN may also renegotiate or update the NAS cryptographic key during a TAU procedure or during NAS PDU transmission. Only when the UE stores the NAS cryptographic key can the UE include NAS data in a NAS PDU or transmit a NAS PDU via underlying signaling, thereby implementing the process of transmitting NAS data using the MAC CE shown in FIG1 to FIG4 and FIG7a to FIG7d.

[0128] It is understood that the underlying signaling includes:

[0129] Media Access Control Element (MAC CE);

[0130] and / or,

[0131] Specific signaling radio bearer SRB.

[0132] It should be noted that both MAC CE and SRB can be transmitted at the MAC layer, so that NAS PDU can be transmitted at the MAC layer, thereby bypassing operations related to wireless link connection and achieving energy saving.

[0133] It is understood that the method further comprises:

[0134] receiving, in a radio resource control (RRC) connected state and monitoring a user equipment specific search space (USS), a scheduling request (SR) resource configuration or a buffer status report (BSR) resource configuration in a power saving state from a RAN node, and obtaining pre-configured SR resources or BSR resources;

[0135] In the energy-saving state, resources for transmitting small data packets are obtained through pre-configured SR resources or BSR resources.

[0136] It should be noted that when small data packets (i.e., NAS PDUs) are transmitted through SR resources or BSR resources, SRBs are not processed by PDCP or PDCP only transparently transmits the NAS information; there is no RLC processing or RLC adopts TM mode, but there is an LCH ID for identifying SRBs. Therefore, the SRB seen at the MAC layer is a regular SDU.

[0137] For example, referring to Figure 9a, which illustrates the process of a UE transmitting SR and BSR using preconfigured resources in an energy-saving state, when the UE is in a normal RRC connection state and is monitoring the USS (e.g., a UE-specific PDCCH), the base station sends an SR or BSR resource configuration. The SR or BSR resource configuration is sent during the RRC connection setup, RRC connection reconfiguration, and RRC connection release phases. The SR and BSR resource configurations are UE-specific uplink configuration resources, including CFRA resources, PUCCH, PUSCH, and uplink signaling for SR; and PUCCH, PUSCH, and uplink signaling for BSR. When configuring SR or BSR resources, the time domain information for the SR or BSR resource configuration must also be configured. This time domain information includes at least one of the following: the start time of the SR or BSR resource, the period of the SR or BSR resource, the end time of the SR or BSR resource, and a timer that determines the end time of the SR or BSR resource. When configuring SR and BSR resources for use in the UE energy-saving state, the USS must also be configured. When the USS configuration is complete, the UE sends a BR or SR to the base station, starts a PDCCH monitoring timer, and stops monitoring the PDCCH after the PDCCH monitoring timer expires (i.e., the UE starts monitoring the PDCCH in FIG9a ). In some embodiments, as shown in FIG9a , after an uplink grant or downlink grant is sent via the PDCCH, the PDCCH monitoring timer is restarted. When the SR or BSR resource configuration is completed in the energy-saving state, a UE-specific RNTI is also configured to identify the UE by the base station or to identify the UE-specific PDCCH by the UE.

[0138] It is understood that the SR resources include at least one of the following: contention-free random access CFRA resources for SR, physical uplink control channel PUCCH resources for SR, uplink signaling for SR, and physical uplink shared channel PUSCH resources for SR;

[0139] BSR resources include at least one of the following: PUCCH resources used for BSR, uplink signaling used for BSR, and PUSCH resources used for BSR.

[0140] For example, as shown in FIG9a , when configuring SR resources, one or more of CFRA resources, PUCCH resources, uplink signaling resources, and PUSCH resources may be selectively configured. For example, if only CFRA resources are configured, or if PUCCH resources, uplink signaling resources, and PUSCH resources are configured simultaneously, those skilled in the art may selectively select one or more resources for configuration based on actual needs.

[0141] For example, as shown in Figure 9a, when performing BSR resource configuration, one or more of the PUCCH resources, uplink signaling and PUSCH resources can be selectively configured, such as configuring only PUCCH resources, configuring uplink signaling and PUSCH resources at the same time, etc. Those skilled in the art can selectively select one or more resources to configure the BSR resource configuration according to actual needs.

[0142] It is understood that the method further comprises:

[0143] While in the RRC connected state and monitoring the USS, time domain information of the SR resource configuration or the BSR resource configuration is also received from the RAN node, where the time domain information includes at least one of the following: a start time of the SR or BSR resource, a period of the SR or BSR resource, an end time of the SR or BSR resource, and a timer for determining the end time of the SR or BSR resource.

[0144] It should be noted that the timer is triggered by the start time of the SR or BSR resource. Timer expiration indicates that the end time of the BR or BSR resource has been reached. The corresponding BR or BSR resource is generated periodically from the start time to the end time of the SR or BSR resource. The SR or BSR resource period determines the interval at which the corresponding SR or BSR resource is generated.

[0145] It is understood that the method further comprises:

[0146] In the process of being in the radio resource control RRC connected state and monitoring the USS, a USS configuration in the energy saving state and / or a specific radio network temporary identifier RNTI configuration is also received from the RAN node.

[0147] It should be noted that, by setting the RNTI, it can be distinguished whether the UE is identified by the base station or the UE-specific PDCCH is identified by the UE.

[0148] It is understood that the method further comprises:

[0149] During the energy-saving state, receiving downlink data and / or downlink signaling transmitted by the RAN node through a downlink grant, wherein the downlink signaling is used for at least one of the following:

[0150] Radio resource configuration / reconfiguration in the RRC connected state, where the radio resource configuration / reconfiguration includes: USS configuration and / or specific RNTI configuration of the UE in the RRC connected state;

[0151] Triggering the UE to switch from energy-saving state to RRC connected state.

[0152] For example, as shown in Figure 9b, Figure 9b is a flowchart of using pre-configured resources for small data transmission in an energy-saving state. As shown in Figure 9b, when the UE is in a normal RRC connection state and is monitoring USS (such as a UE-specific PDCCH), the base station initiates a USS monitoring configuration to the UE in an energy-saving state. The USS monitoring configuration can be sent to the UE via a MAC CE or included in the UE-specific RRC signaling during the RRC connection setup phase, the RRC connection reconfiguration phase, or the RRC connection release phase. The USS configuration includes at least one of: time domain information for USS monitoring, PDCCH frequency position (DARFCH) or frequency bandwidth, PDCCH monitoring interval, PDCCH monitoring duration, or timer. The time domain information includes at least one of the following: the start time of the USS energy-saving state, the end time of the USS energy-saving state, and a timer that determines the end time of the UE energy-saving state (for example, the timer starts from the start time of the UE energy-saving state, and the time when the timer expires is the end time of the USS energy-saving state). The UE starts monitoring the PDCCH according to the USS configuration and starts the PDCCH monitoring timer (or monitors the PDCCH within the maximum PDCCH monitoring time period); the PDCCH monitoring in the energy-saving state is terminated when the PDCCH monitoring timer expires. In some embodiments, the PDCCH monitoring timer can be restarted when an uplink authorization or a downlink authorization is received via the PDCCH. It should be noted that when the base station sends the USS monitoring configuration to the UE, the UE energy-saving state-specific RNTI will also be configured for the base station to identify the UE, or for the UE to identify the UE-specific PDCCH. It should be noted that, as shown in Figure 9b, under energy-saving loading, the downlink authorization can be used for downlink data transmission or downlink signaling transmission, wherein the downlink signaling can be used to configure radio resources / reconfiguration and trigger the UE to switch from the energy-saving state to the RRC connection state, and the radio resources / reconfiguration includes at least one of the USS configuration and specific RNTI configuration of the UE in the RRC connection state.

[0153] 10 , a data transmission method according to the second aspect of the present application is applied to a radio access network RAN ​​node. The method includes the following steps:

[0154] Step S200: Perform underlying signaling transmission with user equipment UE, which carries a non-access stratum protocol data unit (NAS PDU).

[0155] By carrying NAS PDU in the underlying signaling, the NAS PDU can be transparently transmitted in the data link layer with the help of the underlying signaling, without the need for wireless link-related establishment, release, maintenance and reconfiguration operations, thereby making the transmission process simpler and capable of transmitting more data without the need for a fixed period. Therefore, compared with related technologies, the embodiments of the present application can solve the problem of low transmission efficiency of small data transmission technology.

[0156] It is understood that the underlying signaling transmission with the user equipment UE carrying the non-access stratum protocol data unit NAS PDU includes:

[0157] Receive uplink underlying signaling carrying non-access stratum protocol data unit (NAS PDU) sent by UE;

[0158] and / or,

[0159] Send downlink underlying signaling carrying NAS PDU to the UE.

[0160] 7a-7d , taking the RAN node as a base station as an example, the RAN node receives uplink underlying signaling carrying NAS PDU sent by the UE, and the base station sends downlink underlying signaling carrying NAS PDU to the UE.

[0161] It is understood that the underlying signaling transmission with the user equipment UE carrying the non-access stratum protocol data unit NAS PDU includes:

[0162] receiving a first uplink bottom layer signaling sent by the UE and carrying a first NAS UE identifier;

[0163] Sending, to the UE according to the first uplink bottom layer signaling, first downlink bottom layer signaling carrying a second NAS UE identifier, where the second NAS UE identifier is identical to the first NAS UE identifier, or the second NAS UE identifier is identical to a segment in the first NAS UE identifier.

[0164] It should be noted that, referring to Figures 5 and 6, and Figures 1 and 2, taking the transmission of the underlying signaling through the MAC layer as an example, when the UE sends a NAS PDU MAC CE for the first time, the UE sends a first uplink underlying signaling carrying a first NAS UE identifier, so that the base station can identify which UR sends the uplink underlying signaling through the first NAS UE identifier, or when the UE receives a paging message with a downlink transmission indication or a preamble transmission indication message, the first NAS UE identifier is used to enable the base station to identify which UEs are ready to receive downlink underlying signaling.

[0165] It should be noted that the same fragment in the second NAS UE identifier as in the first NAS UE identifier indicates partial identity. The second NAS UE may be bit data of a portion of bits in the first NAS UE. The bit data may be M consecutive bit data or M bit data of the minimum bits that can distinguish different first NAS UE identifiers.

[0166] It is understandable that the first uplink bottom layer signaling includes one or more uplink bottom layer signalings;

[0167] The NAS PDU and the first NAS UE identity are carried by one uplink bottom layer signaling, or the NAS PDU and the first NAS UE identity are carried by different uplink bottom layer signaling.

[0168] It should be noted that the uplink bottom layer signaling refers to the bottom layer signaling transmitted in the uplink direction.

[0169] It should be noted that, for the UE, the first NAS UE identifier and NAS PDU can be sent through one underlying signaling, or can be encapsulated into different underlying signalings for sending. Therefore, the first uplink underlying signaling includes at least one uplink underlying signaling.

[0170] It is understandable that the first downlink bottom layer signaling carries NAS PDU.

[0171] It is understandable that the first downlink bottom layer signaling includes one or more downlink bottom layer signaling;

[0172] The NAS PDU and the second NAS UE identity are carried by one downlink underlying signaling, or the NAS PDU and the first NAS UE identity are carried by different downlink underlying signaling.

[0173] It should be noted that the downlink underlying signaling refers to the underlying signaling transmitted in the downlink direction.

[0174] It should be noted that, for the RAN node, the second NAS UE identifier and NAS PDU can also be sent through one underlying signaling, or can be encapsulated into different underlying signalings for sending. Therefore, the first downlink underlying signaling includes at least one downlink underlying signaling.

[0175] It is understandable that, before receiving the first uplink underlying signaling sent by the UE and carrying the first NAS UE identifier, the method further includes:

[0176] Sending a timer configuration to the UE, so that the UE stops sending the second uplink underlying signaling carrying the NAS PDU and / or stops receiving the second downlink underlying signaling carrying the NAS PDU when the timer exceeds a time limit according to the timer configuration;

[0177] A data transmission completion indication is sent to the UE, so that the UE stops sending the second uplink bottom layer signaling carrying the NAS PDU and / or stops receiving the second downlink bottom layer signaling carrying the NAS PDU according to the data transmission completion indication.

[0178] It is understandable that, before receiving the first uplink underlying signaling sent by the UE and carrying the first NAS UE identifier, the method further includes:

[0179] Receive the leading message sent by the UE;

[0180] A response message is sent to the UE according to the preamble message, wherein the response message is used to instruct the UE to send a first uplink bottom layer signaling carrying a first NAS UE identifier.

[0181] Exemplarily, as shown in Figures 7a to 7d, in some embodiments, taking the RAN node as a base station as an example, the UE sends a preamble message to the base station; the base station sends a response message to the UE. At this time, the access process is completed. After completing the access process, the UE sends an uplink underlying signaling carrying a NAS PDU to the base station, and the base station sends a downlink underlying signaling to the UE to realize small data transmission between the UE and the base station.

[0182] It is understandable that, before receiving the preamble message sent by the RAN node, the method further includes:

[0183] A preamble transmission indication message or a paging message carrying the preamble transmission indication is sent to the UE, where the preamble transmission indication message or the paging message carrying the preamble transmission indication is used to instruct the UE to send a preamble message.

[0184] Exemplarily, as shown in Figure 7b, the base station sends a preamble transmission indication message to the UE to instruct the UE to send preamble information. After receiving the preamble transmission indication message, the UE sends a preamble message to the base station. Accordingly, the base station feeds back a response message to the UE. After receiving the response message, the UE sends uplink underlying signaling (the uplink underlying signaling includes at least a first NAS UE identifier, and in some embodiments, includes a first NAS UE identifier and a NAS PDU); the base station receives the second first NAS UE identifier and feeds back downlink underlying signaling to the UE. At this time, the UE confirms whether the random access process is successfully completed and whether the contention resolution is successful based on the fed-back downlink underlying signaling.

[0185] Exemplarily, as shown in Figures 7c and 7d, a paging message is sent to the UE to instruct the UE to send a preamble message. After the UE receives the paging message, in some embodiments, as shown in Figure 7c, the UE sends a random access preamble to the base station. The base station feeds back a random access response message corresponding to the random access preamble. After receiving the corresponding random access response message, the UE sends a first NAS UE identifier. The base station feeds back a downlink underlying instruction (including at least a second NAS UE identifier, in some embodiments, the downlink underlying instruction includes the second NAS UE identifier and a NAS PDU) based on the first NAS UE identifier. At this time, after receiving the downlink underlying instruction, the UE confirms that the process is successfully completed and the contention resolution is successful. In other embodiments, as shown in Figure 7d, after receiving the paging message, the UE directly sends a MsgA (the upper MsgA includes at least the first NAS UE identifier, in some embodiments, the MsgA includes the first NAS UE identifier and a NAS PDU). After receiving the MsgA, the base station feeds back a corresponding MsgB. At this time, the UE confirms whether the access process is successfully completed and whether the contention resolution is successful based on the MsgB.

[0186] It is understood that the leading message includes at least one of the following:

[0187] Random access preamble;

[0188] Uplink underlying signaling carrying NAS PDU;

[0189] Uplink underlying signaling carrying the first NAS UE identity.

[0190] It should be noted that, in some embodiments, as shown in Figure 7a, the preamble message includes a random access preamble code, an uplink underlying signaling carrying a NAS PDU, and an uplink underlying signaling carrying a first NAS UE identifier; in other embodiments, as shown in Figure 7c, the preamble message includes a random access preamble code and an uplink underlying signaling carrying a first NAS UE identifier; in other embodiments, as shown in Figure 7d, the preamble message includes an uplink underlying signaling carrying a first NAS UE identifier, or an uplink underlying signaling carrying a first NAS UE identifier and a NAS PDU.

[0191] It is understood that the response message includes at least one of the following:

[0192] Random access response information;

[0193] Downlink underlying signaling carrying NAS PDU;

[0194] Downlink underlying signaling carrying the second NAS UE identifier.

[0195] It should be noted that, in some embodiments, as shown in Figure 7a, the response message includes a random access response message, downlink underlying signaling carrying a NAS PDU, and downlink underlying signaling carrying a second NAS UE identifier; in other embodiments, as shown in Figure 7c, the response message includes a random access response message and downlink underlying signaling carrying a second NAS UE identifier; in other embodiments, as shown in Figure 7d, the response message includes downlink underlying signaling carrying a second NAS UE identifier, or downlink underlying signaling carrying a second NAS UE identifier and a NAS PDU.

[0196] It is understandable that the preamble transmission indication message or the paging message carrying the random access preamble transmission indication carries the NAS cryptographic key, where the NAS cryptographic key is used for NAS PDU encryption and / or implicitly indicates whether the UE is allowed to send uplink underlying signaling carrying the NAS PDU, or the authority or capability to send uplink underlying signaling carrying the NAS PDU.

[0197] It is understandable that, before receiving the preamble message sent by the UE, the method further includes:

[0198] Receive a paging message sent by a core network node that carries a downlink NAS PDU transmission indication, where the downlink NAS PDU transmission indication may also be a NAS cryptographic key;

[0199] The paging message carrying the downlink NAS PDU transmission indication is forwarded to the UE.

[0200] Exemplarily, as shown in FIG. 7 c and FIG. 7 d , the core network node sends a paging message carrying a downlink NAS PDU transmission indication, and the base station sends the paging message to the UE to perform the MT process.

[0201] The method also includes:

[0202] Receive the third downlink underlying signaling carrying NAS PDU sent by the core network node.

[0203] The underlying signaling includes:

[0204] Media Access Control Element (MAC) of the Media Access Control Unit;

[0205] and / or,

[0206] Specific signaling radio bearer SRB.

[0207] It should be noted that, after receiving the third downlink underlying signaling, the RAN node may interact with the UE through the MAC CE or SRB.

[0208] The method also includes:

[0209] When the UE is in a radio resource control RRC connected state and monitors the user equipment specific search space USS, a scheduling request SR resource configuration or a buffer status report BSR resource configuration in an energy saving state is also sent to the UE, so that the UE obtains resources for small data packet transmission based on the pre-configured SR resources or BSR resources.

[0210] SR resources include at least one of the following: CFRA resources for SR, PUCCH resources for SR, uplink signaling for SR, and PUSCH resources for SR;

[0211] BSR resources include at least one of the following: PUCCH resources used for BSR, uplink signaling used for BSR, and PUSCH resources used for BSR.

[0212] For example, as shown in Figure 9a, when the UE is in the RRC connection state and monitoring the USS, the base station will send SR resource configuration or BSR resource configuration to the UE in the energy-saving state, so that the UE obtains resources for small data packet transmission based on the pre-configured SR resources or BSR resources for small data transmission.

[0213] The method also includes:

[0214] When the UE is in the RRC connected state and monitoring the USS, time domain information of the SR resource configuration or the BSR resource configuration is also sent to the UE, where the time domain information includes at least one of the following: the start time of the SR or BSR resource, the period of the SR or BSR resource, the end time of the SR or BSR resource, and the timer for determining the end time of the SR or BSR resource.

[0215] The method also includes:

[0216] When the UE is in the RRC connected state and monitors the USS, the USS configuration in the energy saving state and / or the specific radio network temporary identifier RNTI configuration are also sent to the UE.

[0217] Exemplarily, as shown in FIG9b , the UE is in a connected state and in the process of monitoring the USS, and the base station sends the USS monitoring configuration to the UE in an energy-saving state.

[0218] The method also includes:

[0219] While the UE is in an energy-saving state, downlink data and / or downlink signaling is sent to the UE via a downlink grant, where the downlink signaling is used for at least one of the following:

[0220] UE radio RA resource configuration / reconfiguration in RRC connected state, RA resource configuration / reconfiguration including: UE USS configuration and / or specific RNTI configuration in RRC connected state;

[0221] Triggering the UE to switch from energy-saving state to RRC connected state.

[0222] It should be noted that the above-mentioned data transmission method of the embodiment of the present application realizes small data transmission between the RAN node and the UE in three ways. The first is to carry NAS PDU through MAC CE, and then interact directly at the MAC layer without the need for RRC connection and other processing operations. The second way is to configure an independent SRB through the RAN node (such as a base station) or define a default SRB by the protocol, which is specifically used to carry NAS PDU. At this time, the configured SRB has no PDCP processing or PDCP only transparently transmits the NAS information; there is no RLC processing or RLC adopts TM mode, but there is an LCH ID for identifying the SRB; so that the SRB seen by the MAC layer is a regular SDU. The third way is to perform small data transmission through pre-configured SR or BSR resources when the UE is in idle state, and through pre-configured BR or BSR.

[0223] As shown in FIG11 , an embodiment of the present application further provides an electronic device, including:

[0224] One or more processors 101;

[0225] The memory 102 stores one or more programs. When the one or more programs are executed by the one or more processors 101, the one or more processors 101 implement:

[0226] For example, a data transmission method applied to a user equipment UE; or

[0227] For example, a data transmission method applied to a radio access network RAN ​​node.

[0228] The memory 102 is a non-transient network system that can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory 102 may include a high-speed random access memory and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory 102 may optionally include a memory 102 remotely located relative to the processor 101, and these remote memories 102 may be connected to the processor 101 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0229] The memory 102 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 102 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 102 and is called by the processor 101 to execute the methods of the embodiments of this application.

[0230] The processor 101 can be implemented using a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0231] In some embodiments, as shown in FIG11 , the electronic device further includes:

[0232] Input / output interface, used to realize information input and output;

[0233] Communication interface, used to enable communication between this device and other devices. Communication can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, Wi-Fi, Bluetooth, etc.);

[0234] A bus that transmits information between various components of the device (e.g., processor 101, memory 102, input / output interfaces, and communication interfaces);

[0235] The processor 101 , the memory 102 , the input / output interface and the communication interface can be communicatively connected to each other within the device via a bus.

[0236] An embodiment of the present application further provides a computer-readable storage medium storing computer-executable instructions for executing:

[0237] For example, a data transmission method applied to a user equipment UE; or

[0238] For example, a data transmission method applied to a radio access network RAN ​​node.

[0239] An embodiment of the present application further provides a computer program product, including a computer program or computer instructions, wherein the computer program or computer instructions are stored in a computer-readable storage medium. A processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium, and the processor executes the computer program or computer instructions, so that the computer device performs the following operations:

[0240] For example, a data transmission method applied to a user equipment UE; or

[0241] For example, a data transmission method applied to a radio access network RAN ​​node.

[0242] The system architecture and application scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. Those skilled in the art will appreciate that with the evolution of the system architecture and the emergence of new application scenarios, the technical solutions provided in the embodiments of the present application are equally applicable to similar technical problems.

[0243] Those skilled in the art will appreciate that all or some of the steps and systems in the method disclosed above can be implemented as software, firmware, hardware, and appropriate combinations thereof. Some physical components or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, and the computer-readable medium can include computer storage media (or non-transitory media) and communication media (or temporary media). As known to those skilled in the art, the term computer storage media is included in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data) and is volatile and non-volatile, removable, and non-removable. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory, or other memory technology, CD-ROM, digital versatile disks (DVD), or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage, or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, communication media typically embodies computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0244] The above description of some embodiments of the present application with reference to the accompanying drawings does not limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present invention shall be within the scope of the present application.

Claims

1. A data transmission method, applied to a user equipment UE, the method comprising: The underlying signaling transmission carrying the non-access layer protocol data unit NAS PDU is performed with the radio access network RAN ​​node.

2. The method according to claim 1, wherein: The bottom layer signaling transmission carrying the non-access layer protocol data unit NAS PDU with the RAN node includes: Sending uplink underlying signaling carrying non-access stratum protocol data units (NAS PDUs) to RAN nodes; and / or, Receive downlink bottom layer signaling carrying NAS PDU sent by the RAN node.

3. The method according to claim 1, wherein: The bottom layer signaling transmission carrying the non-access layer protocol data unit NAS PDU with the RAN node includes: Sending a first uplink bottom layer signaling carrying a first NAS UE identifier to the RAN node; receiving a first downlink underlying signaling carrying a second NAS UE identifier sent by a RAN node; and When the first NAS UE identifier and the second NAS UE identifier match, a second uplink underlying signaling carrying the NAS PDU is sent to the RAN node and / or a second downlink underlying signaling carrying the NAS PDU sent by the RAN node is received until a preset condition is met.

4. The method according to claim 3, wherein: The first NAS UE identifier and the second NAS UE identifier are determined to match by one of the following steps: If the first NAS UE identifier is the same as the second NAS UE identifier, it is determined that the first NAS UE identifier and the second NAS UE identifier match; or, If the second NAS UE identifier is identical to a segment in the first NAS UE identifier, it is determined that the first NAS UE identifier and the second NAS UE identifier match.

5. The method according to claim 3, wherein: The first uplink bottom layer signaling carries the NAS PDU.

6. The method according to claim 5, wherein: The first uplink bottom layer signaling includes one or more uplink bottom layer signaling; The NAS PDU and the first NAS UE identifier are carried by one uplink bottom layer signaling, or the NAS PDU and the first NAS UE identifier are carried by different uplink bottom layer signaling.

7. The method according to claim 3, wherein: The first downlink bottom layer signaling carries the NAS PDU.

8. The method according to claim 7, wherein: The first downlink bottom layer signaling includes one or more downlink bottom layer signaling; The NAS PDU and the second NAS UE identifier are carried by one downlink underlying signaling, or the NAS PDU and the first NAS UE identifier are carried by different downlink underlying signaling.

9. The method according to claim 3, wherein: The preset conditions include: the timer exceeds the deadline; The timing starting point or re-timing starting point of the timer is: the UE sends the NAS PDU, or the UE receives the NAS PDU, or the UE receives an uplink authorization, or the UE receives a downlink authorization.

10. The method according to claim 3, wherein: The preset condition includes: receiving a data transmission completion indication sent by the RAN node.

11. The method according to claim 3, wherein: Before sending the first uplink bottom layer signaling carrying the first NAS UE identifier to the RAN node, the method further includes: sending a preamble message to the RAN node; and receiving a response message sent by the RAN node according to the preamble message, wherein the response message is used to instruct the UE to send the first uplink bottom layer signaling carrying the first NAS UE identifier, and / or is used to indicate resources allocated by the RAN node to the UE in response to the preamble message for sending the first uplink bottom layer signaling carrying the first NAS UE identifier.

12. The method according to claim 11, wherein: Before sending the preamble message to the RAN node, the method further includes: receiving a preamble transmission indication message or a paging message carrying a preamble transmission indication sent by the RAN node, where the preamble transmission indication message or the paging message carrying the preamble transmission indication is used to instruct the UE to send the preamble message.

13. The method according to claim 11, wherein: The leading message includes at least one of the following: Random access preamble; Uplink underlying signaling carrying NAS PDU; Uplink underlying signaling carrying the first NAS UE identifier.

14. The method according to claim 11, wherein: The response message includes at least one of the following: Random access response information; Downlink underlying signaling carrying NAS PDU; Downlink underlying signaling carrying the second NAS UE identity.

15. The method according to claim 12, wherein: The preamble transmission indication message or the paging message carrying the preamble transmission indication carries a NAS cryptographic key, wherein the NAS cryptographic key is used for NAS PDU encryption and / or implicitly indicates whether the UE is allowed to send uplink underlying signaling carrying NAS PDU, or the authority or capability to send uplink underlying signaling carrying NAS PDU.

16. The method according to claim 1, wherein: Before transmitting the underlying signaling carrying the non-access layer protocol data unit NAS PDU with the RAN node, the method further includes: Perform NAS cryptographic key negotiation with the core network node to obtain whether to allow the sending of uplink underlying signaling carrying NAS PDU, or the authority or capability to send uplink underlying signaling carrying NAS PDU.

17. The method according to claim 16, further comprising: Renegotiate the NAS cryptographic key with the core network node through a tracking area update TAU procedure; or, Obtaining an updated NAS cryptographic key from the core network node through the TAU process; or, renegotiate the NAS cryptographic key with the core network node via a NAS PDU; or, Obtain an updated NAS cryptographic key from the core network node via the NAS PDU.

18. The method according to any one of claims 1 to 17, wherein: The bottom layer signaling includes: Media Access Control Element MAC CE; and / or, Specific signaling radio bearer SRB.

19. The method of claim 1, further comprising: In a process of being in a radio resource control RRC connected state and monitoring a user equipment specific search space USS, receiving a scheduling request SR resource configuration or a buffer status report BSR resource configuration in a power saving state from a RAN node, and obtaining a pre-configured SR resource or BSR resource; and In the process of being in the energy-saving state, resources for transmitting small data packets are obtained through the pre-configured SR resources or BSR resources.

20. The method according to claim 19, wherein: The SR resources include at least one of the following: CFRA resources for contention-free random access of SR, PUCCH resources for physical uplink control channel of SR, uplink signaling for SR, and PUSCH resources for physical uplink shared channel of SR; The BSR resources include at least one of the following: PUCCH resources used for BSR, uplink signaling used for BSR, and PUSCH resources used for BSR.

21. The method according to claim 20, further comprising: In the process of being in the RRC connected state and monitoring the USS, time domain information of the SR resource configuration or the BSR resource configuration is also received from the RAN node, wherein the time domain information includes at least one of the following: the start time of the SR or BSR resource, the period of the SR or BSR resource, the end time of the SR or BSR resource, and the timer for determining the end time of the SR or BSR resource.

22. The method according to claim 21, further comprising: In the process of being in the radio resource control RRC connected state and monitoring the USS, a USS configuration in the energy saving state and / or a specific radio network temporary identifier RNTI configuration is also received from the RAN node.

23. The method according to claim 21, further comprising: In the process of being in the energy-saving state, receiving downlink data and / or downlink signaling transmitted by the RAN node through a downlink grant, wherein the downlink signaling is used for at least one of the following: Radio resource configuration / reconfiguration in RRC connected state, the radio resource configuration / reconfiguration comprising: USS configuration and / or specific RNTI configuration of UE in RRC connected state; Trigger the UE to switch from the energy-saving state to the RRC connected state.

24. A data transmission method, applied to a radio access network RAN ​​node, the method comprising: Perform underlying signaling transmission with user equipment UE carrying non-access layer protocol data unit NAS PDU.

25. The method according to claim 24, wherein: The bottom layer signaling transmission carrying the non-access layer protocol data unit NAS PDU with the user equipment UE includes: Receiving uplink bottom layer signaling carrying a non-access layer protocol data unit NAS PDU sent by the UE; and / or, Sending downlink bottom layer signaling carrying NAS PDU to the UE.

26. The method according to claim 24, wherein: The bottom layer signaling transmission carrying the non-access layer protocol data unit NAS PDU with the user equipment UE includes: receiving a first uplink bottom layer signaling carrying a first NAS UE identifier sent by the UE; Sending, according to the first uplink bottom layer signaling, a first downlink bottom layer signaling carrying a second NAS UE identifier to the UE, wherein the second NAS UE identifier is the same as the first NAS UE identifier, or the second NAS UE identifier is the same as a segment in the first NAS UE identifier.

27. The method according to claim 26, wherein: The first downlink bottom layer signaling carries the NAS PDU.

28. The method of claim 24, further comprising: When the UE is in a radio resource control RRC connection state and monitors a user equipment specific search space USS, a scheduling request SR resource configuration or a buffer status report BSR resource configuration in a power saving state is also sent to the UE, so that the UE obtains resources for small data packet transmission based on pre-configured SR resources or BSR resources.

29. An electronic device comprising: one or more processors; A memory having one or more programs stored thereon, when the one or more programs are executed by the one or more processors, the one or more processors implement: The data transmission method according to any one of claims 1 to 23; or, A data transmission method as described in any one of claims 24 to 28.

30. A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the computer program implements: The data transmission method according to any one of claims 1 to 23; or, A data transmission method as described in any one of claims 24 to 28.

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