Downlink flow control method for F1-U interface of 5G base station

Abstract

The invention discloses a downlink flow control method for an F1-U interface of a 5G base station. The method comprises the following steps: step 1, periodically counting Buffer usage rates and packetloss rates borne by each side of a gNBDU; step 2, calculating the size of a Buffer expected by each bearer according to the statistical information; step 3, allocating Buffer sizes to the F1-U interfaces in sequence according to the bearing priorities; and step 4, enabling the gNB-DU to notify the gNB-CU-UP to update the Buffer size of the F1-U interface. According to the downlink flow control method for the F1-U interface of the 5G base station, the buffer fed back by the RLC is dynamically adjusted according to the actual air interface rate, so that the downlink flow of the F1-U tends to bethe same as the air interface flow, and the F1-U side packet loss caused by full occupation of the buffer size on the gNB-DU side is avoided; and according to the bearing priorities, the buffer sizeof each bearing is globally and dynamically adjusted, so that the situation that the low-priority bearing occupies the buffer size of the high-priority bearing is avoided.

Description

technical field [0001] The invention relates to the technical field of 5G communication, in particular to a method for controlling downlink flow of an F1-U interface of a 5G base station. Background technique [0002] The F1-U interface is a standard user plane interface between gNB-CU-UP and gNB-DU. gNB-CU-UP contains PDCP entities, and gNB-DU contains RLC entities. The F1-U interface mainly has two types of data frames: [0003] 1. DL USER DATA frame: transmits user data from the PDCP entity to the RLC entity, that is, PDCP PDU; [0004] 2. DL DATA DELIVERY STATUS frame: transmits the feedback from the RLC entity to the PDCP entity, that is, the downlink data transmission status feedback and control. [0005] Among them, the downlink flow control of the F1-U interface can be controlled through the Desired buffer size for the data radio bearer field in the DL DATA DELIVERY STATUS frame. Through this field, the RLC entity tells the PDCP entity the current expected Buffer si...

AI Technical Summary

Problems solved by technology

[0007] 1. If the F1-U downlink traffic exceeds the air interface traffic, the Buffer size on the DU side will be full, resulting in packet loss on the F1-U side, affecting the sliding of the PDCP window on the UE side, resulting in delay jitter and PDCP packet loss;

[0008] 2. Interaction between bearers, low priority bearers may occupy too much buffer size, resulting in too small available buffer size for high priority bearers

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