Latency Reduction (srsRAN + Open5GS)

[andergalvaan]

Hi,

I'm currently deploying a 5G network using srsRAN with a CU/DU split architecture, together with Open5GS. Each component runs on a separate physical server: the CU and DU are on 10.98.1.155, and 5GC is on 10.98.1.133. For the RF front end, I'm using a USRP B210, and the UE is a Quectel RM520N-GL module.

The software versions in use are:

• UHD: 4.1.0.5-3
• srsRAN: commit d8bfdc9
• Open5GS: 2.7.5

My main objective is to minimize end-to-end latency while also maintaining or improving uplink throughput performance. To help with this, I'm using the low_latency.yml configuration provided by srsRAN for the DU. With this setup, I am achieving latency values around 16 ms and uplink throughput of approximately 18 Mbps.

I've attached the following for reference: the .yml configuration files for both the CU and DU, as well as screenshots showing the deployment logs of each. Additionally, I've included images that demonstrate the successful attachment of the UE to the network, the results of ping tests to the UPF, and the iperf3 uplink test results from the UE to the UPF.

Any suggestions or insights on improving latency and uplink throughput in this setup would be greatly appreciated.

Thanks in advance!
Ander

cu.zip
du.zip
ue.zip

[fllay]

There is an excellent paper in this post #234 It seems that grant free will give you lower latency.

[andergalvaan]

Hi @fllay, yes, I have read some of the papers they mentioned, but none of them include an implementation showing how latency can be minimized. Have you tried to reduce latency below 15 or 16 ms? Thank you!