Analysis of Real-Time Video Streaming and Throughput Performance Using the Open Air Interface Stack on Multiple UEs

The Open Air Interface (OAI) is an open-source project that implements 3GPP standards using general-purpose x86 computer hardware and commercial off-the-shelf (COTS) software-defined radio devices, such as the Universal Software Radio Peripheral (USRP). This paper presents a reference implementation for connecting a COTS UE, such as the Quectel and the Google Pixel 6a, to a 5G Stand-Alone (SA) testbed, based on USRP radios, the USRP Hardware Driver (UHD) software, and the OAI 5G NR software stack. The testbed is used to test and analyse the performance of video streaming over a 5G NR network for different TDD formats. In order to perform this analysis, we register the 5G COTS UE with the OAI 5G Core Network (CN) via the OAI 5G gNB, stream real-time videos vary the channel conditions, monitor the modulation coding scheme (MCS) adaptation on the gNB side, and observe the resulting quality at the UE side. We detail the implementation of the testbed, and the obstacles encountered when establishing the RF connection over-the-cable (OTC) and over-the-air (OTA).