  As 5G networks strive to support advanced time-critical applications, such as
immersive Extended Reality (XR), cloud gaming, and autonomous driving, the
demand for Real-time Broadband Communication (RTBC) grows. In this article, we
present the main mechanisms of Low Latency, Low Loss, and Scalable Throughput
(L4S). Subsequently, we investigate the support and challenges of L4S
technology in the latest 3GPP 5G-Advanced Release 18 (R18) standard. Our case
study, using a prototype system for a real-time communication (RTC)
application, demonstrates the superiority of L4S technology. The experimental
results show that, compared with the GCC algorithm, the proposed L4S-GCC
algorithm can reduce the stalling rate by 1.51%-2.80% and increase the
bandwidth utilization by 11.4%-31.4%. The results emphasize the immense
potential of L4S technology in enhancing transmission performance in
time-critical applications.
