Data transmission method, terminal, and computer program product

Abstract

Embodiments of the present disclosure provide a data transmission method, a terminal, and a computer program product. The method comprises: a second transmitting end receives first data from a first transmitting end, the first data comprising a packet data convergence protocol data packet (PDCP PDU) and a packet data convergence protocol sequence number (PDCP SN), and the PDCP PDU not carrying the PDCP SN; and the second transmitting end performs data transmission on the basis of the PDCP SN.

Description

Data transmission methods, terminals, and computer program products

[0001] Cross-references to related applications

[0002] This application is based on and claims priority to Chinese patent application CN202510061934.4, filed on January 14, 2025, entitled “Data Transmission Method, Terminal and Computer Program Product”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of communications, and more specifically, to a data transmission method, a terminal, and a computer program product. Background Technology

[0004] In fifth-generation mobile communication systems (5G NR), the Packet Data Convergence Protocol (PDCP) and the Radio Link Control (RLC) layer jointly manage the data transmission process, including key operations such as packet compression, encryption, reassembly, sequencing, and retransmission. Traditionally, each layer's Protocol Data Unit (PDU) carries its own Sequence Number (SN), such as the PDCP SN in the PDCP PDU and the RLC SN in the RLC PDU, to enable packet identification and processing. However, carrying sequence numbers consumes valuable radio resources, especially in resource-constrained wireless communication environments, which can negatively impact overall communication efficiency and network performance. Summary of the Invention

[0005] This disclosure provides a data transmission method, a terminal, and a computer program product to at least solve the problems of low communication efficiency and poor network performance caused by wireless resource occupation in the related art.

[0006] According to one embodiment of this disclosure, a data transmission method is provided, comprising: a second transmitting end receiving first data from a first transmitting end, the first data including a Packet Data Convergence Protocol Data Packet (PDCP PDU) and a Packet Data Convergence Protocol Sequence Number (PDCP SN), wherein the PDCP PDU does not carry the PDCP SN; and the second transmitting end performing data transmission based on the PDCP SN.

[0007] According to another embodiment of this disclosure, a data transmission method is provided, comprising: a first receiving end receiving second data from a second receiving end, the second data including a Radio Link Control Service Data Packet (RLC SDU) and a corresponding Service Data Packet Sequence Number (SDU SN); the first receiving end determining a Packet Data Convergence Protocol Sequence Number (PDCP SN) corresponding to a Packet Data Convergence Protocol Data Packet (PDCP PDU) based on the SDU SN.

[0008] According to another embodiment of this disclosure, a data transmission method is provided, comprising: a second sending end receiving first data from a first sending end, the first data including a Packet Data Convergence Protocol Data Packet (PDCP PDU), the PDCP PDU carrying a Packet Data Convergence Protocol Sequence Number (PDCP SN); the second sending end determining a Service Data Packet Sequence Number (SDU SN) based on the PDCP SN and performing data transmission.

[0009] According to yet another embodiment of this disclosure, a terminal is provided, the terminal including a receiver, a transmitter, and a processor, the receiver being configured to receive first configuration signaling in response to a terminal located at the Packet Data Convergence Protocol (PDCP) layer being associated with a terminal located at the Radio Link Control (RLC) layer, the first configuration signaling being configured to instruct at least one of the receiver, the transmitter, and the processor to perform the steps in any of the above method embodiments.

[0010] According to yet another embodiment of this disclosure, a terminal is provided, the terminal including a receiver, a transmitter, and a processor, the receiver being configured to receive second configuration signaling in response to a terminal located at the Packet Data Convergence Protocol (PDCP) layer being associated with a terminal located at the Radio Link Control (RLC) layer, the second configuration signaling being configured to instruct at least one of the receiver, the transmitter, and the processor to perform the steps in any of the above method embodiments.

[0011] According to yet another embodiment of this disclosure, a computer-readable storage medium is also provided, wherein a computer program is stored therein, wherein the computer program is configured to perform the steps in any of the above method embodiments when it is run.

[0012] According to yet another embodiment of this disclosure, an electronic device is also provided, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0013] According to yet another embodiment of this disclosure, a computer program product is also provided, including a computer program that, when executed by a processor, implements the steps in any of the above method embodiments. Attached Figure Description

[0014] Figure 1 is a schematic diagram of the protocol architecture between the UE and the base station in related technologies;

[0015] Figure 2 is a hardware structure block diagram of a mobile terminal using the data transmission method implemented in an embodiment of this disclosure;

[0016] Figure 3 is a flowchart of a data transmission method according to an embodiment of the present disclosure;

[0017] Figure 4 is another flowchart of the data transmission method according to an embodiment of the present disclosure;

[0018] Figure 5 is another flowchart of the data transmission method according to an embodiment of the present disclosure;

[0019] Figure 6 is a schematic diagram of the structure of the terminal in which the data transmission method of this embodiment of the present disclosure is running;

[0020] Figure 7 is a structural example diagram of the PDCP data PDU in Example 1;

[0021] Figure 8 is a schematic diagram of the structure of the RLC header when the RLC header includes the RLC SN in Embodiment 2;

[0022] Figure 9 is another structural diagram of the RLC header when the RLC header includes the RLC SN in Embodiment 2;

[0023] Figure 10 is a schematic diagram of the structure of the RLC header when the RLC header in Embodiment 2 does not contain the RLC SN. Detailed Implementation

[0024] The embodiments of this disclosure will be described in detail below with reference to the accompanying drawings and examples.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of the embodiments of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0026] In related technologies, the user plane enables the transmission of user data and Radio Resource Control (RRC) messages between user equipment (UE) and access network elements. For example, in a wireless interface protocol of a wireless communication system, the two ends of the communication are the UE and the radio access network element (e.g., a base station), and the user plane consists of multiple protocol layers. Figure 1 is a schematic diagram of the protocol architecture between the UE and the base station in related technologies. As shown in Figure 1, it includes the physical layer, the Medium Access Control (MAC) layer, the RLC layer, the PDCP layer, and the Service Data Adaptation Protocol (SDAP) layer.

[0027] In related technologies, PDCP is located in the PDCP sublayer, and a UE can configure multiple PDCPs. Each PDCP is used to carry data for a radio bearer, including the Data Radio Bearer (DRB) and the Signaling Radio Bearer (SRB). The PDCP layer includes a PDCP transmitter and a PDCP receiver.

[0028] The behavior of the PDCP transmitter includes: receiving PDCP Service Data Units (SDUs) from the upper layer and associating a COUNT value with the received PDCP SDU. The COUNT value consists of two parts: the Hyper Frame Number (HFN) and the PDCP SN. The PDCP SN is the least significant bit of the COUNT, and the HFN is the most significant bit.

[0029] In related technologies, the PDCP receiver constructs a PDCP PDU corresponding to the PDCP SDU. This PDCP PDU includes the PDCP SDU and its protocol header, which also contains the PDCP SN. If a PDCP discard timer is configured, the PDCP transmitter starts a discard timer for each PDCP SDU received from the upper layer. When the PDCP transmitter receives a PDCP status report, or the lower layer confirms that the PDCP SDU has been successfully received, the timer is stopped. If the timer expires, the PDCP transmitter discards the PDCP SDU and its corresponding PDCP PDU, or all PDCP SDUs and their corresponding PDCP PDUs belonging to the same PDCP set as the discarded PDCP SDU.

[0030] The PDCP transmitter maintains the following variable: TX_NEXT: This variable is the COUNT value of the next PDCP SDU to be sent. Except for setting the SRB for the continued use of the variable, the initial value of this variable is 0.

[0031] In related technologies, the PDCP receiver maintains the following variables:

[0032] RX_DELIV is the COUNT value of the first PDCP SDU that has not been delivered to the upper layer but is still waiting to be received, and is the COUNT value of the next PDCP SDU that is delivered to the upper layer in sequence. In addition to the sidelink broadcast channel, the SRB and MRB are configured by variables, with an initial value of 0.

[0033] RX_NEXT is the next COUNT value after the maximum COUNT value in the PDCP SDU in the PDCP receive buffer, i.e., the COUNT value of the next PDCP SDU expected to be received.

[0034] RCVD_COUNT is the COUNT value of the currently received PDCP SDU.

[0035] RX_REORD is the next COUNT value of the PDCP data PDU that triggered the reordering timer.

[0036] In related technologies, reordering and in-order delivery behaviors include:

[0037] Set RX_DELIV to the COUNT value of the first PDCP SDU that has not been submitted to the upper layer.

[0038] If RCVD_COUNT = RX_DELIV, then PDCP SDUs in the receive buffer starting from RX_RCVD with COUNT values greater than or equal to RX_DELIV and consecutive COUNT values are delivered to the upper layer.

[0039] If RX_NEXT is greater than RX_DELIV, start the reordering timer and set the value of RX_REORD to RX_NEXT.

[0040] If the reordering timer is running and RX_DELIV is greater than or equal to RC_REORD, stop the reordering timer. If the reordering timer expires, deliver PDCP SDUs with COUNT values less than RX_REORD in the buffer to its upper layer, and deliver consecutive PDCP SDUs starting from the COUNT value of RX_REORD to its upper layer. Update the value of RX_DELIV. If RX_DELIV < RX_NEXT, start the reordering timer (at this time, there are still undelivered / lost PDCP SDUs).

[0041] In the related art, the behaviors of the PDCP sender include: for AM DRBs of PDCP without suspension, starting from the first PDCP data SDU that has not been successfully acknowledged by its lower layer, send or re - send all PDCP SDUs associated with the PDCP SN before PDCP re - establishment to its lower layer protocol in ascending order of their COUNT values. For AM DRBs of PDCP that are suspended, starting from the first PDCP data SDU that has not been successfully acknowledged by its lower layer, send each PDCP SDU associated with the PDCP SN but not yet sent to its lower layer protocol to the lower layer protocol in ascending order of its COUNT value. For DRBs in the UM (Unacknowledged Mode) mode, send each PDCP SDU associated with the PDCP SN but not yet sent to its lower layer protocol to the lower layer protocol in ascending order of its COUNT value.

[0042] In related technologies, the PDCP receiver constructs a PDCP status report based on instructions from its upper layer (e.g., RRC) and sends it to the corresponding PDCP transmitter. Reasons for triggering a PDCP status report include: upper layer requesting PDCP entity re-establishment; upper layer requesting PDCP data recovery; upper layer requesting uplink data switching; and upper layer reconfiguring the PDCP to release Dynamic Allocation of Power Sources (DAPS).

[0043] The PDCP status report includes: a COUNT value for a lost PDCP SDU, indicating the COUNT value of the first PDCP SDU that the PDCP receiver did not receive (i.e., the RX_DELIV value); or a bitmap indicating the reception status of one or more PDCP SDUs, where each bit indicates the reception status of a PDCP SDU following the first unreceived PDCP SDU, i.e., whether the PDCP SDU was received; or, the PDCP transmitter determines whether a PDCP SDU was received based on the content of the PDCP status report; or, for a received PDCP SDU, the PDCP transmitter removes it from the transmit buffer queue.

[0044] In related technologies, the RLC sublayer is located below the PDCP layer and above the MAC layer in the protocol stack. A UE can configure multiple RLC transmitters and receivers. Each RLC is used to carry data for a radio bearer (RB), including the data radio bearer (DRB) and the signaling radio bearer (SRB). A PDCP entity may be associated with one or more RLC entities. For example, in PDCP duplication, one PDCP entity may be associated with two RLC entities, and one PDCP PDU entity may be sent to two RLC entities for transmission. In split radio bearer technology, i.e., split DRB / SRB, one PDCP entity is associated with two RLC entities, and each PDCP PDU is carried and transmitted by one of its RLC entities. The PDCP entity selects the RLC entity to transmit to based on the implementation. Associating a PDCP entity with an RLC entity means that the PDCP transmitter sends the PDCP PDU to the associated RLC transmitter entity, and the RLC receiver sends the received RLC SDU to the associated PDCP receiver entity.

[0045] In related technologies, the behavior of the RLC transmitter includes: receiving PDCP PDUs (i.e., RLC SDUs) sent by PDCP; and constructing RLC PDUs based on the received RLC SDUs. Alternatively, the operation of constructing RLC PDUs may include segmentation of the RLC SDUs. Segmentation involves dividing an RLC SDU into several segments and constructing an RLC PDU for each RLC segment. The size of the RLC segment matches the size of the RLC PDU indicated by its underlying protocol; for example, the size of the RLC PDU constructed after segmentation is less than or equal to the size of the RLC PDU indicated by the MAC layer.

[0046] An RLC PDU may contain a complete RLC SDU or a fragment of an RLC SDU. An AM RLC PDU contains an RLC header, which contains an RLC sequence number, i.e., the RLC SN. UM RLC determines whether to include the RLC SN based on whether the RLC PDU contains a fragment of the RLC SDU, and then sends the RLC PDU to its lower-layer protocol, i.e., the MAC layer.

[0047] In related technologies, the AM RLC transmitter maintains an RLC transmission window. The AM RLC transmitter maintains the following variables: TX_Next_ACK: The RLC SN of the next RLC SDU awaiting successful reception within the RLC transmission window, initially set to 0. TX_Next: This variable represents the RLC SN of the next RLC SDU, also initially set to 0.

[0048] The range of the RLC transmission window is the interval: [TX_Next_ACK, TX_Next_ACK + AM transmission window size].

[0049] The RLC transmitter will not send RLC SDUs exceeding the transmission window range. When the RLC transmitter receives an RLC status report, it updates the value of TX_Next_ACK according to the acknowledgment of the received RLC SN indicated in the RLC status report and moves the RLC transmission window. In other words, the RLC transmission window moves based on acknowledgment of the RLC SDUs received by the receiver.

[0050] The UM RLC transmitter maintains the following variable: TX_Next: This variable is the value of the RLC SN for the next RLC SDU.

[0051] In related technologies, the AM RLC receiver maintains the following variables:

[0052] RX_NEXT is the next RLC SN after the SN of the last fully received RLC SDU, or the smallest RLC SN among the unreceived RLC SDUs. It is also the lower edge of the receive window, and its initial value is 0.

[0053] RX_Next_Highest is the maximum value of the RLC SN in the received RLC SDU plus 1.

[0054] RX_Next_Status_Trigger is the next RLC SN of the RLC SDU that triggers the recombination timer.

[0055] RX_Highest_Status is the highest possible RLC SN that can be indicated as the ACK_SN field when a status report is constructed; its initial value is 0.

[0056] The range of the RLC receive window is the interval of RLC SN [RX_Next, RX_Next + AM receive window size].

[0057] In related technologies, when the SN of a received RLC PDU is not within the RLC receive window, the RLC discards the RLC PDU. When the RLC receiver detects a lost RLC SDU or RLC SDU fragment, for example, when there is a gap between RX_Next and RX_Next_Highest where no RLC SDU or RLC fragment has been received, the RLC receiver starts a reassembly timer and sets the value of RX_Next_Status_Trigger to RX_Next_Highest. If all RLC SDUs before RX_Next_Status_Trigger at the start of the reassembly timer have been successfully received, or there is no RLC fragment gap, or due to the movement of the RLC receive window, RX_Next_Status_Trigger falls outside the receive window and is not equal to the receive window size of RX_Next+AM, then the reassembly timer stops. When the reassembly timer times out, the value of RX_Highest_Status is updated to be greater than or equal to the SN of the first RLC SDU that was not fully received. If there is an unreceived RLC SDU or RLC fragmentation hole between RX_Highest_Status and RX_Next_Highest, the reassembly timer is started, and the value of RX_Next_Status_Trigger is updated to RX_Next_Highest. The UM RLC receiver maintains an RLC reassembly window.

[0058] In related technologies, UM RLC maintains the following variables:

[0059] RX_Next_Reassembly: This variable represents the earliest RLC SN that has not yet been successfully assembled within the reassembly window. Its initial value is 0.

[0060] RX_Timer_Trigger: This variable is the next RLC SN that triggers the recombination timer.

[0061] RX_Next_Highest: This variable is the next RLC SN after the highest RLC SN of the received RLC PDU. This variable is also the upper edge of the recombination window. Its initial value is 0.

[0062] The range of the RLC reconstruction window is [RX_Next_Highest – UM reconstruction window size, RX_Next_Highest].

[0063] The position of the RLC reassembly window changes according to the highest value of the received RLC SN. That is, the RLC reassembly window moves whenever an RLC SN value greater than the current RX_Next_Highest is received. After the RLC reassembly window moves, RLC discards RLC PDUs / SDUs that have fallen outside the RLC reassembly window but have not yet been successfully reassembled.

[0064] In related technologies, when an unreceived RLC PDU appears within the reassembly window (e.g., RX_Next_Highest > RX_Next_Reassemble + 1), or when there are discontinuously received RLC fragments, a reassembly timer is started, and the value of RX_Timer_Trigger is set to RX_Next_Highest. If the RX_Timer_Trigger falls outside the reassembly window after the window moves, or if all RLC PDUs that triggered the reassembly timer are successfully received, the reassembly timer is stopped from being reset. If the reassembly timer times out, the value of RX_Next_Reassemble is set to the first incompletely received RLC SN after the RLC SN that triggered the reassembly timer, and RLC fragments with SNs shorter than RX_Next_Reassemble are discarded. The start conditions for the reassembly timer are checked; if they are met, the reassembly timer is started.

[0065] In related technologies, the reasons that trigger the AM RLC receiver to report a status include: the reassembly timer expires; or, the receiver receives a polling request from the RLC transmitter to request an RLC status report; or, the AM RLC receiver constructs an RLC status report and sends it to the RLC transmitter.

[0066] The status includes the following: the SN of the unreceived RLC SDU, i.e., the NACK SN. Alternatively, the position of the fragment within the RLC SDU, i.e., the segment offset start and segment offset end. Or, a range representing a group of unreceived RLC SDU SNs. ACK_SN: The next unreceived RLC SN not indicated in the status report. RLC SDUs with SNs smaller than this are considered successfully received, except those indicated as NACK in the status report.

[0067] When the RLC transmitter receives the RLC status report, it executes the ARQ function based on the information in the RLC status report, which is to retransmit the lost RLC SDU or RLC SDU fragments.

[0068] When an RLC transmitter receives an instruction from its upper-layer protocol to discard an RLC SDU, it discards the RLC SDU if the RLC SDU or its fragments have not been sent to the lower layer. Discarding an RLC SDU must not create a gap in the RLC SN, i.e., a discontinuous RLC SN.

[0069] In related technologies, when an upper layer requests RLC reconstruction: all RLC SDUs, RLC SDU fragments, and RLC PDUs in the RLC cache are discarded. All timers, including reassembly timers, are stopped. Variables maintained by the RLC are restored to their initial values ​​as agreed upon in the protocol.

[0070] The method embodiments provided in this application can be executed in a mobile terminal, computer terminal, or similar computing device. Taking a mobile terminal as an example, FIG2 is a hardware structure block diagram of a mobile terminal running the data transmission method according to the embodiments of this disclosure. As shown in FIG2, the mobile terminal may include one or more (only one is shown in FIG2) processors 202 (processor 202 may include, but is not limited to, processing devices such as microprocessors MCUs or programmable logic devices FPGAs) and a memory 204 for storing data. The mobile terminal may also include a transmission device 206 for communication functions and an input / output device 208. Those skilled in the art will understand that the structure shown in FIG2 is only illustrative and does not limit the structure of the mobile terminal. For example, the mobile terminal may also include more or fewer components than shown in FIG2, or have a different configuration than shown in FIG2.

[0071] The memory 204 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the data transmission method in this embodiment. The processor 202 executes various functional applications and data processing by running the computer program stored in the memory 204, thus implementing the aforementioned method. The memory 204 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 204 may further include memory remotely located relative to the processor 202, and these remote memories can be connected to the mobile terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0072] The transmission device 206 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the mobile terminal's communication provider. In one example, the transmission device 206 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 206 may be a Radio Frequency (RF) module, used for wireless communication with the Internet.

[0073] This disclosure provides a data transmission method. Figure 3 is a flowchart of the data transmission method according to this disclosure. As shown in Figure 3, the process includes the following steps:

[0074] In step S302, the second sending end receives the first data from the first sending end. The first data includes a Packet Data Convergence Protocol Data Packet (PDCP PDU) and a Packet Data Convergence Protocol Sequence Number (PDCP SN), and the PDCP PDU does not carry the PDCP SN.

[0075] In one exemplary embodiment, the first transmitting end is located at the Packet Data Convergence Protocol (PDCP) layer, and the second transmitting end is located at the Radio Link Control (RLC) layer.

[0076] In one exemplary embodiment, the first transmitting end and the second transmitting end are the same or different network devices, wherein the type of network device includes at least one of the following: access network element; base station; user terminal UE.

[0077] In one exemplary embodiment, the first data further includes a sequence count value COUNT, which is used to determine the PDCP SN.

[0078] Step S304: The second transmitting end transmits data based on the PDCP SN.

[0079] In one exemplary embodiment, the second transmitting end performs data transmission based on the PDCP SN, including: the second transmitting end determining a Radio Link Control Service Data Packet (RLC SDU) based on the first data; the second transmitting end determining a Service Data Packet Sequence Number (SDU SN) based on the PDCP SN; and the second transmitting end constructing a Radio Link Control Protocol Data Packet (RLC PDU) based on the RLC SDU, wherein the RLC PDU carries the Radio Link Control Sequence Number (RLC SN), and the value of the RLC SN is equal to the value of the SDU SN.

[0080] In one exemplary embodiment, the second sending end determines the service data packet sequence number SDU SN based on the PDCP SN, including: the value of the SDU SN is the value of the PDCP SN; or, the value of the SDU SN is the value of COUNT; or, the value of the SDU SN is the low-order part of the value of COUNT; or, the SDU SN is the PDCP SN; or the SDU SN is the value of COUNT; or the SDU SN is the low-order part of COUNT.

[0081] Figure 4 is another flowchart of the data transmission method according to an embodiment of the present disclosure. As shown in Figure 4, the process includes the following steps:

[0082] In step S402, the first receiving end receives second data from the second receiving end. The second data includes Radio Link Control Service Data Packet (RLC SDU) and the corresponding Service Data Packet Sequence Number (SDU SN).

[0083] In one exemplary embodiment, the first receiving end is located at the Packet Data Convergence Protocol (PDCP) layer, and the second receiving end is located at the Radio Link Control (RLC) layer.

[0084] In one exemplary embodiment, the first receiving end and the second receiving end are the same or different network devices, wherein the type of network device includes at least one of the following: access network element; base station; user terminal UE.

[0085] In one exemplary embodiment, the RLC SDU is received directly by the second receiving end, or obtained by the second receiving end by reassembling fragments of the Radio Link Control Service Data Packet RLC SDU.

[0086] In one exemplary embodiment, the SDU SN is equal to the Radio Link Control Sequence Number (RLC SN) corresponding to the Radio Link Control Service Data Packet (RLC SDU), or the SDU SN is the Radio Link Control Sequence Number (RLC SN) corresponding to the Radio Link Control Service Data Packet (RLC SDU).

[0087] Step S404: The first receiving end determines the Packet Data Convergence Protocol Sequence Number (PDCP SN) corresponding to the Packet Data Convergence Protocol Data Packet (PDCP PDU) based on the SDU SN.

[0088] Figure 5 is another flowchart of the data transmission method according to an embodiment of the present disclosure. As shown in Figure 5, the process includes the following steps:

[0089] In step S502, the second sending end receives first data from the first sending end. The first data includes a Packet Data Convergence Protocol Data Packet (PDCP PDU), and the PDCP PDU carries a Packet Data Convergence Protocol Sequence Number (PDCP SN).

[0090] In one exemplary embodiment, the first transmitting end is located at the Packet Data Convergence Protocol (PDCP) layer, and the second transmitting end is located at the Radio Link Control (RLC) layer.

[0091] In one exemplary embodiment, the first transmitting end and the second transmitting end are the same or different network devices, wherein the type of network device includes at least one of the following: access network element; base station; user terminal UE.

[0092] In one exemplary embodiment, the first data further includes a sequence count value COUNT or a PDCP SN.

[0093] In step S504, the second sending end determines the service data packet sequence number SDU SN based on the PDCP SN and performs data transmission.

[0094] In one exemplary embodiment, the second transmitting end determines the service data packet sequence number SDU SN based on the PDCP SN and performs data transmission, including: the second transmitting end determines the Radio Link Control Service Data Packet RLC SDU based on the PDCP PDU; the second transmitting end uses the PDCP SN or the value of the COUNT associated with the PDCP PDU or the low-order part of the value of the COUNT associated with the PDCP PDU as the SDU SN, that is, the SDU SN is the PDCP SN or the value of the COUNT associated with the PDCP PDU or the low-order part of the value of the COUNT associated with the PDCP PDU; the second transmitting end constructs the Radio Link Control Protocol Data Packet RLC PDU based on the RLC SDU, and determines whether the RLC PDU carries the Radio Link Control Sequence Number RLC SN based on the RLC SDU.

[0095] In one exemplary embodiment, in response to the second transmitter being in acknowledgment mode, the second transmitter determines whether the RLC PDU carries a Radio Link Control Sequence Number (RLC SN) based on the RLC SDU, including: if the RLC SDU is not fragmented, the RLC PDU does not carry an RLC SN; or, if the RLC SDU is fragmented, the RLC PDU carries an RLC SN, and the value of the RLC SN is equal to the value of the SDU SN.

[0096] In one exemplary embodiment, the RLC header of the RLC PDU includes an indication field that indicates whether the RLC PDU carries an RLC SN.

[0097] The above steps provide a data transmission method, comprising: a second transmitting end receiving first data from a first transmitting end, the first data including a Packet Data Convergence Protocol (PDCP) PDU and a Packet Data Convergence Protocol (PDCP) Sequence Number (PDCP SN), wherein the PDCP PDU does not carry the PDCP SN; and the second transmitting end performing data transmission based on the PDCP SN. This embodiment of the present disclosure solves the problem of low communication efficiency and poor network performance caused by the occupancy of wireless resources in related technologies, achieving the effect of improving communication efficiency and network performance.

[0098] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solutions of the embodiments of this disclosure, or the parts that contribute to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the embodiments of this disclosure.

[0099] This disclosure also provides a terminal. FIG6 is a schematic diagram of the structure of the terminal operating the data transmission method of this disclosure. As shown in FIG6, the terminal 60 includes a receiver 610, a transmitter 620 and a processor 630. The receiver 610 is used to receive a first configuration signaling in response to a terminal located at the Packet Data Convergence Protocol (PDCP) layer being associated with a terminal located at the Radio Link Control (RLC) layer. The first configuration signaling is used to instruct at least one of the receiver 610, the transmitter 620 and the processor 630 to perform the steps of the above data transmission method.

[0100] In one exemplary embodiment, the first configuration signaling is used to indicate whether the Packet Data Convergence Protocol Data Packet (PDCP PDU) carries a Packet Data Convergence Protocol Sequence Number (PDCP SN); or, the first configuration signaling is used to indicate whether the Radio Link Control Sequence Number (RLC SN) is determined based on the value of the Service Data Packet Sequence Number (SDU SN).

[0101] The terminal provided in this embodiment includes a receiver, a transmitter, and a processor. The receiver is used to receive a second configuration signaling in response to a terminal located at the Packet Data Convergence Protocol (PDCP) layer being associated with a terminal located at the Radio Link Control (RLC) layer. The second configuration signaling is used to instruct at least one of the receiver, transmitter, and processor to perform the steps of the above-described data transmission method.

[0102] In one exemplary embodiment, the second configuration signaling is used to indicate whether the Packet Data Convergence Protocol (PDCP) PDU carries the Packet Data Convergence Protocol Sequence Number (PDCP SN); or, the second configuration signaling is used to indicate whether the Radio Link Control (RLC) Sequence Number (RLC SN) is determined based on the value of the Service Packet Sequence Number (SDU SN); or, the second configuration signaling is used to indicate whether the RLC PDU carries the RLC SN in the case of RLC SDU fragmentation; or, the second configuration signaling is used to indicate whether the RLC PDU carries the RLC SN in the case of no RLC SDU fragmentation.

[0103] This embodiment also provides a data transmission device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0104] In this embodiment of the disclosure, the data transmission device may further include different modules. The naming and functional division of the modules can be selected in different ways according to the actual situation. No specific restrictions are imposed here, as long as the steps of the data transmission method of the above method embodiment can be implemented.

[0105] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0106] Embodiments of this disclosure also provide a computer-readable storage medium storing a computer program configured to perform the steps in any of the above method embodiments when executed.

[0107] In one exemplary embodiment, the aforementioned computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, read-only memory (ROM), random access memory (RAM), portable hard disk, magnetic disk, or optical disk.

[0108] Embodiments of this disclosure also provide an electronic device including a memory and a processor, the memory storing a computer program and the processor being configured to run the computer program to perform the steps in any of the above method embodiments.

[0109] In one exemplary embodiment, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0110] This disclosure also provides a computer program product, including a computer program that, when executed by a processor, implements the steps in any of the above method embodiments.

[0111] In one exemplary embodiment, the computer program product described above includes a non-volatile computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the methods described in various embodiments of this application.

[0112] Specific examples in this embodiment can be found in the examples described in the above embodiments and exemplary implementations, and will not be repeated here.

[0113] Obviously, those skilled in the art should understand that the modules or steps of the embodiments of this disclosure described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. They can be implemented using computer-executable program code, and thus can be stored in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented herein, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the embodiments of this disclosure are not limited to any particular combination of hardware and software.

[0114] To enable those skilled in the art to better understand the technical solutions of the embodiments of this disclosure, the following description is provided in conjunction with different embodiments.

[0115] Example 1

[0116] In this embodiment of the disclosure, the PDCP transmitter is the first transmitter in the above embodiment, the RLC transmitter is the second transmitter in the above embodiment, the PDCP receiver is the first receiver in the above embodiment, and the RLC receiver is the second receiver in the above embodiment.

[0117] In this embodiment, a scheme that carries the RLC SN only in the RLC HEADER is introduced.

[0118] In this embodiment, the PDCP transmitter sends the PDCP PDU and its associated PDCP SN or COUNT value to its associated RLC transmitter, where the PDCP PDU header does not contain the PDCP SN. The RLC transmitter carries the RLC SN in the RLC PDU header. The value of the RLC SN is equal to the PDCP SN or COUNT value or the lower-order part of the COUNT value. The RLC receiver sends the received RLC SDU and its associated SDU SN to the PDCP receiver. The PDCP receiver determines the PDCP SN or COUNT value associated with the received PDCP PDU (i.e., RLC SDU). The SDU SN value is equal to the RLC SN, or the SDU SN is the RLC SN.

[0119] In this embodiment, the behavior of the PDCP transmitter includes: the PDCP transmitter receiving a PDCP SDU from the upper layer; associating a COUNT value with the PDCP SDU; determining the PDCP SN based on the COUNT value; constructing a PDCP PDU, and not carrying the PDCP SN in the PDCP PDU header.

[0120] In this embodiment, the PDCP transmitter submits the PDCP PDU and its associated PDCP SN or COUNT to its associated lower-level RLC transmitter entity. For example, in one embodiment, the PDCP PDU and its associated PDCP SN or COUNT can be sent to the associated lower-level RLC transmitter entity as first data.

[0121] In this embodiment, the behavior of the RLC transmitter includes: receiving the PDCP PDU sent by the PDCP, i.e., the RLC SDU, and the corresponding PDCP SN or COUNT; and maintaining RLC transmitter variables and transmission window based on the SDU SN or RLC SN.

[0122] In this embodiment, the SDU SN is equal to the PDCP SN, or the COUNT value, or the least significant bits of the COUNT value, or the SDU SN is the PDCP SN, or the COUNT, or the least significant bits of the COUNT.

[0123] The RLC transmitter constructs an RLC PDU based on the received RLC SDU. The constructed RLC PDU may contain a complete RLC SDU or an RLC fragment. The RLC PDU contains an RLC header, which contains an RLC SN. The value of the RLC SN is the value of the SDU SN.

[0124] In one embodiment, the PDCP is submitted to the RLC layer as a PDCP PDU and a PDCP SN or COUNT, where the PDCP SN is equal to N1 and the lower part of the COUNT value is equal to N2. The RLC layer fragments the RLC SDU (PDCP SDU) to construct RLC PDUs, such as RLC PDU#1, RLC PDU#2, and RLC PDU#3.

[0125] For the three RLC PDUs mentioned above, including the RLC SN, set the value of the RLC SN to N1 or N2.

[0126] In this embodiment, if the RLC receiver receives an RLC PDU containing RLC fragments, it reassembles them into an RLC SDU.

[0127] In one embodiment, RLC PDUs #1, #2, and #3, which all have the same RLC SN of N, are reassembled into an RLC SDU. The RLC SN associated with this RLC SDU is N.

[0128] In this embodiment, the RLC receiver performs the following based on the received RLC SN or SDU SN: RLC status reporting, ARQ, receive window or reassembly window, and / or maintains RLC receiver variables. The SDU SN is equal to the RLC SN of the RLC SDU, or determined based on the RLC SN. The reassembled RLC SDU, or the complete RLC SDU contained in the RLC PDU, and its corresponding SDU SN, are submitted to the PDCP receiver.

[0129] In this embodiment, the PDCP receiver receives second data from the RLC receiver. The second data includes the RLC SDU (i.e., the PDCP PDU) and its corresponding SDU SN. Based on the SDU SN, the PDCP SN of the PDCP PDU is determined. The PDCP receiver determines the COUNT value associated with the PDCP PDU based on the set PDCP SN.

[0130] Based on the configuration and the PDCP COUNT value, the PDCP receiver performs the following functions: decryption and integrity verification; duplicate detection and discarding of duplicate PDCP SDUs; reordering and delivery to the upper layer protocol in order.

[0131] In this embodiment, the UE determines whether to use this embodiment based on the following conditions:

[0132] Network devices indicate whether to use the method of this embodiment via signaling. The network may indicate all or part of the method provided in this embodiment in the signaling for configuring PDCP and / or RLC (e.g., the first configuration signaling).

[0133] In one embodiment, the first configuration signaling is used to indicate whether the PDCP header contains a PDCP SN; or, the first configuration signaling is used to indicate whether the RLC SN uses the value of the PDCP SN; or, the first configuration signaling is used to indicate, by protocol agreement or by signaling, that if a PDCP entity is associated with only one RLC entity, then the method of this embodiment shall be applied to the PDCP and RLC.

[0134] In one embodiment, by agreement or signaling, if a PDCP entity is associated with more than one RLC entity, including PDCP duplication and split DRB configurations, under these configurations, a PDCP PDU is sent to more than one RLC, or to one or more of multiple RLCs. In this case, the data transmission method provided in this embodiment is not applied.

[0135] Figure 7 is a structural example of the PDCP data PDU in Embodiment 1. As shown in Figure 7, R: reserved. Data: data payload field. MAC-I: This field contains the message authentication code.

[0136] Through the embodiments disclosed herein, only the RLC sequence number needs to be carried at the RLC layer; the PDCP PDU does not need to carry the PDCP SN. This saves radio resources of the radio interface. Simultaneously, it achieves the functionality of both the traditional PDCP and RLC protocol layers. The network can be configured to instruct the UE whether to apply the method of this embodiment, or the UE can apply the method of this embodiment under specific agreed-upon configuration conditions through protocol agreements. For example, by sending a first configuration command, etc.

[0137] Example 2

[0138] In this embodiment of the disclosure, the PDCP transmitter is the first transmitter in the above embodiment, the RLC transmitter is the second transmitter in the above embodiment, the PDCP receiver is the first receiver in the above embodiment, and the RLC receiver is the second receiver in the above embodiment.

[0139] In this embodiment, a scheme for RLC to carry RLC SN on demand is introduced.

[0140] In this embodiment, the header of the PDCP PDU contains the PDCP SN and the RLC in AM mode. The header of the RLC PDU is determined to contain the RLC SN based on whether the RLC PDU contains RLC fragments.

[0141] In this embodiment, the PDCP transmitter receives a PDCP SDU from the upper layer. A COUNT value is associated with the PDCP SDU. A PDCP PDU is constructed, carrying a PDCP SN in its header. The PDCP SN is the low-order part of the COUNT value. The PDCP transmitter submits the PDCP PDU, along with its optionally associated PDCP SN or COUNT value, to the associated lower layer: the RLC transmitter.

[0142] In this embodiment, the RLC transmitter receives a PDCP PDU (i.e., an RLC SDU) submitted by the PDCP, and optionally, a PDCP SN or COUNT associated with the PDCP PDU. An RLC PDU is constructed based on the received RLC SDU. The RLC transmitter maintains its transmission window and RLC transmitter variables based on the SDU SN or RLC SN. The SDU SN is the sequence number of the RLC SDU, and its value is equal to the PDCP SN, or COUNT value, or the lower-order part of the COUNT value of the corresponding PDCP PDU, or simply the PDCP SN, or COUNT value, or the lower-order part of the COUNT value of the corresponding PDCP PDU. In one embodiment, the RLC transmitter receives first data from the PDCP transmitter, the first data including a PDCP PDU, which carries the PDCP SN.

[0143] In this embodiment, the RLC transmitter determines whether to fragment the RLC SDU based on the size of the RLC PDU and the size of the RLC SDU as indicated by the lower-layer protocol of the RLC.

[0144] Whether to include the RLC SN in the RLC header depends on whether the RLC SDU is fragmented. In one embodiment, if the RLC SDU is not fragmented, an RLC PDU contains a complete RLC SDU and is submitted to the lower-layer protocol; the RLC PDU does not contain the RLC SN. If the RLC SDU needs to be fragmented, an RLC SDU is divided into several segments, and an RLC PDU is constructed for each RLC segment, with the RLC SN included in the RLC header. The RLC SN is equal to the SDU SN.

[0145] In one embodiment, the RLC header indicates whether the RLC header contains an RLC SN, or indicates whether the RLC PDU contains an RLC fragment.

[0146] In one embodiment, a PDCP is submitted to the RLC with a PDCP PDU and a PDCP SN value N1, or an associated COUNT value N2; then the RLC SDU's SDU SN value is N1, or the lower-order part of N2. After the RLC fragments the RLC SDU (i.e., the PDCP SDU), it constructs RLC PDU#1, RLC PDU#2, and RLC PDU#3.

[0147] For the three RLC PDUs mentioned above, each includes an RLC header, which contains an RLC SN. The value of the RLC SN is N1 or the lower-order part of N2. The RLC header indicates that an RLC SN is included, or indicates that the RLC PDU contains RLC fragments. If an RLC SDU does not require fragmentation, i.e., an RLC PDU contains a complete RLC SDU, then the RLC header does not contain an RLC SN. The RLC header either indicates that an RLC SN is not included, or indicates that the RLC PDU contains a complete RLC SDU.

[0148] In this embodiment, in the structure of the RLC header, the indicator field, namely the X field, is used to indicate whether the RLC header contains an RLC SN.

[0149] Figure 8 is a schematic diagram of the structure of the RLC header when the RLC header contains the RLC SN in Embodiment 2. As shown in Figure 8, X indicates that the RLC header contains the RLC SN.

[0150] Figure 9 is another structural diagram of the RLC header when the RLC header in Embodiment 2 includes the RLC SN. As shown in Figure 9, the length of the RLC SN is 18 bits, where X indicates that the RLC header includes the RLC SN.

[0151] Figure 10 is a schematic diagram of the structure of the RLC header when the RLC header does not contain the RLC SN in Embodiment 2. As shown in Figure 10, X indicates that the RLC header does not contain the RLC SN.

[0152] In this embodiment, the RLC receiver receives the RLC PDU sent by the MAC.

[0153] In one embodiment, if the received RLC PDU contains a complete RLC SDU, or if the RLC header does not contain an RLC SN, then the RLC SDU contained in the RLC PDU is delivered to the associated PDCP receiver.

[0154] In one embodiment, if the received RLC PDU contains RLC fragments, or the RLC header indicates that it contains an RLC SN, then the received RLC PDU, along with other RLC PDUs having the same RLC SN, is reassembled into a complete RLC SDU. For example, in the example above, RLCs #1, #2, and #3 are reassembled into a complete RLC SDU.

[0155] In this embodiment, the RLC receiver delivers the assembled RLC SDU to the associated PDCP receiver. RLC PDUs that are not assembled into a complete RLC SDU are placed in the RLC receive buffer. The RLC receiver performs the following tasks based on the SDU SN or RLC SN: RLC status reporting, ARQ, receive window or reassembly window, and / or maintains RLC receiver variables. The value of the SDU SN is equal to the RLC SN, or is an SDU SN determined based on the RLC SN, or the SDU SN is the RLC SN.

[0156] In this embodiment, the PDCP receiver receives a PDCP PDU delivered from its underlying layer. The PDCP SN of the received PDCP PDU is determined. Based on the configured PDCP SN, the PDCP receiver determines the COUNT value associated with the PDCP PDU. According to the configuration, based on the PDCP COUNT value, the following functions are performed: decryption, integrity verification; discarding duplicate received PDCP SDUs; reordering; and sequential delivery.

[0157] In this embodiment, the UE determines whether to use the method of this embodiment based on the following conditions:

[0158] The network indicates whether to use the method of this embodiment via signaling (e.g., second configuration signaling). The network may indicate all or part of the method provided in this embodiment in the signaling for configuring PDCP and / or RLC. For example, the second configuration signaling is used to indicate whether the PDCP header contains a PDCP SN; or, the second configuration signaling is used to indicate whether the RLC SN uses the value of the PDCP SN; or, the second configuration signaling is used to indicate whether the RLC SN is carried when the RLC PDU contains a fragment of the RLC SDU; or, the second configuration signaling is used to indicate whether the RLC SN is included when the RLCPDU contains a complete RLC SDU.

[0159] Alternatively, the UE may specify through protocol agreement or signaling that if a PDCP is associated with only one RLC, then the method of this embodiment shall be applied to both the PDCP and the RLC. The PDCP and RLC each comprise a transmitter and a receiver, respectively.

[0160] Alternatively, the UE may specify via protocol or signaling that if a PDCP is associated with more than one RLC, including PDCP duplication and split DRB configurations, a PDCP PDU may be sent to more than one RLC, or to one or more of multiple RLCs. In this case, the method provided in this embodiment will not be applied.

[0161] Through the embodiments disclosed herein, for AM RLC and UM RLC, the RLC SN is included only when the RLC PDU contains an RLC fragment, which achieves the effect of saving network resources. Simultaneously, the network can be configured to instruct the UE whether to apply the method of this embodiment, or the UE can apply the method of this embodiment under specific agreed-upon configuration conditions through protocol agreement.

[0162] The above description is merely a preferred embodiment of this disclosure and is not intended to limit the scope of this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for data transmission, comprising: receiving, by a second transmitter, first data from a first transmitter, wherein the first data comprises a packet data convergence protocol (PDCP) packet data unit (PDU) and a PDCP sequence number (SN), and the PDCP PDU does not carry the PDCP SN; transmitting, by the second transmitter, data based on the PDCP SN. 2.The method of claim 1, wherein: the first transmitter is located at a PDCP layer, and the second transmitter is located at a radio link control (RLC) layer.

3. The method of claim 2, wherein, the first transmitter and the second transmitter are the same or different network devices, wherein the network devices comprise at least one of the following: an access network element, a base station, and a user equipment (UE). 4.The method of claim 1, wherein: the first data further comprises a COUNT value, wherein the COUNT value is used to determine the PDCP SN.

5. The method of claim 4, wherein, transmitting, by the second transmitter, data based on the PDCP SN, comprises: determining, by the second transmitter, an RLC SDU based on the first data; determining, by the second transmitter, an SDU SN based on the PDCP SN; constructing, by the second transmitter, an RLC PDU based on the RLC SDU, wherein the RLC PDU carries an RLC SN, and a value of the RLC SN is equal to a value of the SDU SN.

6. The method of claim 5, wherein, determining, by the second transmitter, an SDU SN based on the PDCP SN, comprises: the value of the SDU SN is equal to the value of the PDCP SN; or, the value of the SDU SN is equal to the value of the COUNT; or, the value of the SDU SN is a low bit part of the value of the COUNT; or, the SDU SN is equal to the PDCP SN; or, the SDU SN is equal to the COUNT; or, the SDU SN is a low bit part of the COUNT. 7.A method for data transmission, comprising: receiving, by a first receiver, second data from a second receiver, wherein the second data comprises an RLC SDU and a corresponding SDU SN; determining, by the first receiver, a PDCP SN corresponding to a PDCP PDU based on the SDU SN. 8.The method of claim 7, wherein: the first receiver is located at a PDCP layer, and the second receiver is located at an RLC layer.

9. The method of claim 8, wherein, the first receiver and the second receiver are the same or different network devices, wherein the network devices comprise at least one of the following: an access network element, a base station, and a user equipment (UE). 10.The method of claim 7, wherein: The RLC SDU is received directly by the second receiving end or is obtained by the second receiving end reassembling radio link control service data unit (RLC SDU) fragments.

11. The method of claim 7, wherein, The SDU SN is equal to a radio link control sequence number (RLC SN) corresponding to a radio link control service data unit (RLC SDU) based on the second receiving end.

12. A data transmission method, comprising: a second transmitting end receiving first data from a first transmitting end, the first data comprising packet data convergence protocol data units (PDCP PDUs) carrying packet data convergence protocol sequence numbers (PDCP SNs); the second transmitting end determining service data unit (SDU) SNs based on the PDCP SNs for data transmission.

13. The method of claim 12, wherein, the first transmitting end is located at a packet data convergence protocol (PDCP) layer and the second transmitting end is located at a radio link control (RLC) layer.

14. The method of claim 13, wherein, The first transmitting end and the second transmitting end are the same or different network devices, and the network devices include at least one of the following: an access network element; a base station; and a user equipment (UE).

15. The method of claim 12, wherein, the first data further comprises a sequence counter value (COUNT) or the PDCP SN.

16. The method of claim 15, wherein, The second transmitting end determines service data unit (SDU) SNs based on the PDCP SNs for data transmission, comprising: the second transmitting end determining radio link control service data units (RLC SDUs) based on the PDCP PDUs; the second transmitting end taking the PDCP SN or a value of a COUNT associated with the PDCP PDU or a low bit part of the value of the COUNT associated with the PDCP PDU as the SDU SN; the second transmitting end constructing radio link control protocol data units (RLC PDUs) based on the RLC SDUs and determining whether the RLC PDUs carry radio link control sequence numbers (RLC SNs) based on the RLC SDUs.

17. The method of claim 16, wherein, In response to the second transmitting end being in an acknowledgement mode, the second transmitting end determines whether the RLC PDUs carry RLC SNs based on the RLC SDUs, comprising: in a case where the RLC SDU is not fragmented, the RLC PDU does not carry the RLC SN; or in a case where the RLC SDU is fragmented, the RLC PDU carries the RLC SN, and a value of the RLC SN is equal to a value of the SDU SN.

18. The method of claim 17, wherein, an RLC header of the RLC PDU comprises an indication field set to indicate whether the RLC PDU carries the RLC SN.

19. A terminal comprising a receiver, a transmitter and a processor, the receiver being arranged to receive first configuration signaling in response to an association of a terminal at a packet data convergence protocol (PDCP) layer with a terminal at a radio link control (RLC) layer, the first configuration signaling being arranged to instruct at least one of the receiver, the transmitter and the processor to perform the steps of the method according to any one of claims 1 to 11.

20. The terminal according to claim 19, wherein the first configuration signaling is arranged to instruct whether a packet data convergence protocol data packet (PDCP PDU) carries a packet data convergence protocol sequence number (PDCP SN) or not; or the first configuration signaling is arranged to instruct whether a radio link control sequence number (RLC SN) is determined based on a value of a service data packet sequence number (SDU SN) or not.

21. A terminal comprising a receiver, a transmitter and a processor, the receiver being arranged to receive second configuration signaling in response to an association of a terminal at a packet data convergence protocol (PDCP) layer with a terminal at a radio link control (RLC) layer, the second configuration signaling being arranged to instruct at least one of the receiver, the transmitter and the processor to perform the steps of the method according to any one of claims 12 to 18.

22. The terminal according to claim 21, wherein the second configuration signaling is arranged to instruct whether a packet data convergence protocol data packet (PDCP PDU) carries a packet data convergence protocol sequence number (PDCP SN) or not; or the second configuration signaling is arranged to instruct whether a radio link control sequence number (RLC SN) is determined based on a value of a service data packet sequence number (SDU SN) or not; or the second configuration signaling is arranged to instruct whether the RLC PDU carries the RLC SN in case of a radio link control service data packet (RLC SDU) fragmentation; or the second configuration signaling is arranged to instruct whether the RLC PDU carries the RLC SN in case of no fragmentation of the RLC SDU. the computer program, which computer program is executed by the processor, implements the steps of the method according to any one of claims 1 to 11 or the steps of the method according to any one of claims 12 to 18.

24. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor, when executing the computer program, implements the steps of the method according to any one of claims 1 to 11 or the steps of the method according to any one of claims 12 to 18.

25. A computer program product comprising a computer program, which computer program, when executed by a processor, implements the steps of the method according to any one of claims 1 to 11 or the steps of the method according to any one of claims 12 to 18. ​ 23. A computer readable storage medium having stored therein a computer program, wherein, ​ ​ ​

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