A method to prevent out-of-order delivery of 5G SDAP SDUs

Abstract

The application provides a method for preventing 5G SDAP SDU disorderly delivery, and belongs to the technical field of 5G communication. In the application, when the mapping rule of a certain QoS flow and DRB changes, the sender SDAP entity constructs an end-marker K control PDU, submits the PDCP entity of the DRB originally corresponding to the QoS flow, and then submits the data of the QoS flow to the PDCP entity of the newly corresponding DRB. When the mapping rule of a certain QoS flow and DRB changes, the receiver SDAP entity receives the data of the QoS flow from the PDCP entity of the DRB originally corresponding to the QoS flow, and also receives the data of the QoS flow from the PDCP entity of the newly corresponding DRB. Compared with the existing SDAP layer data processing operation, the application can process the data receiving disorder situation caused by the change of the mapping relationship between the QoS flow and the DRB, and ensure that the data is delivered to the upper layer in sequence.

Description

Technical Field

[0001] This invention relates to the field of 5G communication technology, and in particular to a method for preventing out-of-order delivery of 5G SDAP SDUs. Background Technology

[0002] In 5G systems, the sending SDAP (Service Data Adaptation Protocol) entity submits the QoS stream data to the corresponding DRB's PDCP (Packet Data Convergence Protocol) entity according to the mapping rules between the QoS stream and the DRB (Data Radio Bearer). The receiving SDAP entity then forwards the data received from the corresponding DRB's PDCP entity to the upper layer. When the mapping rules between the QoS stream and the DRB change, the sending SDAP entity submits the QoS stream data to the new corresponding DRB's PDCP entity. Due to the impact of underlying scheduling, the data transmitted through the original DRB may arrive at the receiving SDAP entity later than the data transmitted through the new corresponding DRB.

[0003] According to the current protocol, the receiving SDAP entity forwards data to the upper layer as soon as it receives it. This means that if data transmitted via the corresponding new DRB arrives first, it will be forwarded to the upper layer first, leading to out-of-order delivery. Summary of the Invention

[0004] To address the issue that changes in the mapping rules of QoS flows and DRBs during existing 5G SDAP data processing operations may lead to out-of-order delivery of SDAP SDUs to the upper layer, this invention proposes a method to prevent out-of-order delivery of 5G SDAP SDUs. This method distinguishes between data before and after the mapping rule change based on the end-marker control PDU (Protocol Data Unit) in SDAP, thereby ensuring that data is delivered to the upper layer in order.

[0005] The technical solution adopted in this invention is as follows:

[0006] A method for preventing out-of-order delivery of 5G SDAP SDUs, characterized in that,

[0007] When the mapping relationship between a QoS flow and the DRB changes, the SDAP entity performs the following operations:

[0008] (101) Record the original DRB and the new DRB of this QoS flow;

[0009] (102) Construct an SDAP end-marker PDU for this QoS flow and submit it to the PDCP entity of the original corresponding DRB;

[0010] (103) Start a timer for this QoS flow to wait for the SDAP end-marker PDU;

[0011] When an SDAP entity receives an SDAP PDU from a lower layer, it performs the following operations:

[0012] (201) Obtain the QoS flow identifier QFI from the SDAP header, and check if the QoS flow identified by this QFI has a timer waiting for the SDAP end-marker PDU to run; if not, go to step (202), otherwise go to step (203);

[0013] (202) If it is an SDAP data PDU, then obtain the SDAP SDU and send it to the upper layer; otherwise, discard the SDAP PDU.

[0014] (203) If it is an SDAP end-marker PDU, proceed to step (204); if it is an SDAP data PDU, proceed to step (207).

[0015] (204) Check the source of this SDAP end-marker PDU. If it originates from the PDCP entity of the original corresponding DRB, proceed to step (205); otherwise, proceed to step (206).

[0016] (205) Stop the timer waiting for the SDAP end-marker PDU of this QoS flow, clear the original DRB record corresponding to this QoS flow, and then send the SDAP SDU in the buffer queue corresponding to this QoS flow to the upper layer.

[0017] (206) Discard this SDAP end-marker PDU;

[0018] (207) Check the source of this SDAP dataPDU. If it originates from the PDCP entity of the original corresponding DRB, obtain the SDAP SDU and deliver it to the upper layer; otherwise, obtain the SDAP SDU and put it into the buffer queue corresponding to the QoS flow.

[0019] When the timer for a QoS flow waiting for an SDAP end-marker PDU expires, the SDAP entity performs the following operations:

[0020] (301) Clear the DRB record originally corresponding to this QoS flow;

[0021] (302) Send the SDAP SDU in the cache queue corresponding to the QoS flow to the upper layer.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. In this invention, when the mapping rule between a QoS flow and a DRB changes, the sending SDAP entity constructs an end-markerk control PDU and submits it to the PDCP entity of the original DRB corresponding to the QoS flow. Then, it submits the data of the QoS flow to the PDCP entity of the newly corresponding DRB.

[0024] 2. In this invention, when the mapping rule between a QoS flow and a DRB changes, the receiving SDAP entity receives data for the QoS flow from both the PDCP entity of the original corresponding DRB and the PDCP entity of the new corresponding DRB. In the former case, if the received data is an SDAP data PDU for the QoS flow, the SDAP SDU is retrieved from it and sent to the upper layer; if the received data is an SDAP end-marker PDU for the QoS flow, subsequent data for the QoS flow will not be received from this path, and the cached SDAP SDU for the QoS flow should be sent to the upper layer. In the latter case, if the SDAP data PDU for the QoS flow is received before the corresponding SDAP end-marker PDU is received, the SDAP SDU is retrieved from it and placed in the cache; if the SDAP end-marker PDU has already been received, the SDAP SDU is retrieved from it and immediately sent to the upper layer without caching.

[0025] In summary, compared with existing SDAP layer data processing operations, this invention can handle the situation where data reception is out of order when the mapping relationship between QoS streams and DRBs changes, ensuring that data is delivered to the upper layer in order. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of data transmission before the change in the QoS flow and DRB mapping relationship.

[0027] Figure 2 This is a schematic diagram of data transmission after the change in the QoS flow and DRB mapping relationship.

[0028] Figure 3 This is a diagram illustrating the receipt of new data before the end-marker PDU is received.

[0029] Figure 4This is a diagram illustrating the old data received before the end-marker PDU was received.

[0030] Figure 5 This is a schematic diagram of data reception after the end-marker PDU is received. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings.

[0032] A method for preventing out-of-order delivery of 5G SDAP SDUs, characterized in that,

[0033] When the mapping relationship between a QoS flow and the DRB changes, the SDAP entity performs the following operations:

[0034] (101) Record the original DRB and the new DRB of this QoS flow;

[0035] (102) Construct an SDAP end-marker PDU for this QoS flow and submit it to the PDCP entity of the original corresponding DRB;

[0036] (103) Start a timer for this QoS flow to wait for the SDAP end-marker PDU;

[0037] When an SDAP entity receives an SDAP PDU from a lower layer, it performs the following operations:

[0038] (201) Obtain the QoS flow identifier QFI from the SDAP header, and check if the QoS flow identified by this QFI has a timer waiting for the SDAP end-marker PDU to run; if not, go to step (202), otherwise go to step (203);

[0039] (202) If it is an SDAP data PDU, then obtain the SDAP SDU and send it to the upper layer; otherwise, discard the SDAP PDU.

[0040] (203) If it is an SDAP end-marker PDU, proceed to step (204); if it is an SDAP data PDU, proceed to step (207).

[0041] (204) Check the source of this SDAP end-marker PDU. If it originates from the PDCP entity of the original corresponding DRB, proceed to step (205); otherwise, proceed to step (206).

[0042] (205) Stop the timer waiting for the SDAP end-marker PDU of this QoS flow, clear the original DRB record corresponding to this QoS flow, and then send the SDAP SDU in the buffer queue corresponding to this QoS flow to the upper layer.

[0043] (206) Discard this SDAP end-marker PDU;

[0044] (207) Check the source of this SDAP dataPDU. If it originates from the PDCP entity of the original corresponding DRB, obtain the SDAP SDU and deliver it to the upper layer; otherwise, obtain the SDAP SDU and put it into the buffer queue corresponding to the QoS flow.

[0045] When the timer for a QoS flow waiting for an SDAP end-marker PDU expires, the SDAP entity performs the following operations:

[0046] (301) Clear the DRB record originally corresponding to this QoS flow;

[0047] (302) Send the SDAP SDU in the cache queue corresponding to the QoS flow to the upper layer.

[0048] Here are more specific examples:

[0049] This example has three QoS streams and two DRBs.

[0050] exist Figure 1 In this configuration, QoS flows 1 and 2 are mapped to DRB1, and QoS flow 3 is mapped to DRB2. Therefore, the sending SDAP entity submits packet 1 of QoS flow 1 and packet 1 of QoS flow 2 to the PDCP entity of DRB1, and submits packet 1 of QoS flow 3 to the PDCP entity of DRB2.

[0051] exist Figure 2 In this process, the mapping relationships of QoS flows 1 and 3 to DRBs remain unchanged, while QoS flow 2 is mapped to DRB2. Therefore, the sending SDAP entity submits packet 2 of QoS flow 1 and the end-marker PDU of QoS flow 2 to the PDCP entity of DRB1, and submits packet 2 of QoS flow 2 and packet 2 of QoS flow 3 to the PDCP entity of DRB2. The receiving SDAP entity starts a timer for QoS flow 2 to wait for the end-marker PDU.

[0052] exist Figure 3In the process, the receiving SDAP entity receives packet 1 from QoS flow 1 and packet 1 from QoS flow 3. Since no corresponding timer is running for the waiting end-marker PDU, these two packets are forwarded to the upper layer. The receiving SDAP entity also receives packet 2 from QoS flow 2. Since a corresponding timer is running for the waiting end-marker PDU, and this packet originates from the PDCP entity of the newly mapped DRB, the SDAP entity puts it into the buffer queue of QoS flow 2.

[0053] exist Figure 4 In the process, the receiving SDAP entity receives packet 1 of QoS flow 2. Since a timer for a corresponding end-marker PDU is running, and this packet originates from the PDCP entity of the originally mapped DRB, the SDAP entity forwards it to the upper layer. The receiving SDAP entity also receives packet 2 of QoS flow 1 and packet 2 of QoS flow 3. Since no timer for a corresponding end-marker PDU is running, both packets are forwarded to the upper layer.

[0054] exist Figure 5 In the process, the receiving SDAP entity receives the end-marker PDU of QoS flow 2, stops the corresponding timer, and sends data packet 2 in the buffer queue of QoS flow 2 to the upper layer.

Claims

1. A method for preventing out-of-order delivery of 5G SDAP SDUs, characterized in that, When the mapping relationship between a QoS flow and the DRB changes, the SDAP entity performs the following operations: (101) Record the original DRB and the new DRB of this QoS flow; (102) Construct an SDAP end-marker PDU for this QoS flow and submit it to the PDCP entity of the original corresponding DRB; (103) Start a timer for this QoS flow to wait for the SDAP end-marker PDU; When an SDAP entity receives an SDAP PDU from a lower layer, it performs the following operations: (201) Obtain the QoS flow identifier QFI from the SDAP header, and check if the QoS flow identified by this QFI has a timer waiting for the SDAPend-marker PDU to run; if not, go to step (202), otherwise go to step (203); (202) If it is an SDAP data PDU, then obtain the SDAP SDU and send it to the upper layer; otherwise, discard the SDAP PDU. (203) If it is an SDAP end-marker PDU, proceed to step (204); if it is an SDAP data PDU, proceed to step (207). (204) Check the source of this SDAP end-marker PDU. If it originates from the PDCP entity of the original corresponding DRB, proceed to step (205); otherwise, proceed to step (206). (205) Stop the timer waiting for the SDAP end-marker PDU of this QoS flow, clear the original DRB record corresponding to this QoS flow, and then send the SDAP SDU in the buffer queue corresponding to this QoS flow to the upper layer. (206) Discard this SDAP end-marker PDU; (207) Check the source of this SDAP dataPDU. If it originates from the PDCP entity of the original corresponding DRB, obtain the SDAP SDU and deliver it to the upper layer; otherwise, obtain the SDAP SDU and put it into the buffer queue corresponding to the QoS flow. When the timer for a QoS flow waiting for an SDAP end-marker PDU expires, the SDAP entity performs the following operations: (301) Clear the DRB record originally corresponding to this QoS flow; (302) Send the SDAP SDU in the cache queue corresponding to the QoS flow to the upper layer.

Images