CC-OLIA: A dynamic congestion control algorithm for multipath QUIC in mobile networks

High-quality services in today's mobile networks require stable delivery of bandwidth-intensive network content. Multipath QUIC (MPQUIC), as a multipath protocol that extends QUIC, can utilize multiple paths to support stable and efficient transmission. The standard coupled congestion control algorithm in MPQUIC synchronizes these paths to manage congestion, meeting fairness requirements and improving transmission efficiency. However, current algorithms' Congestion Window (CWND) reduction approach significantly decreases CWND upon packet loss, which lowers effective throughput, regardless of the congestion origin. Furthermore, the uncoupled Slow-Start (SS) in MPQUIC leads to independent exponential CWND growth on each path, potentially causing buffer overflow. To address these issues, we propose the CC-OLIA, which incorporates Packet Loss Classifcation (PLC) and Coupled Slow-Start (CSS). The PLC distinguishes between congestion-induced and random packet losses, adjusting CWND reduction accordingly to maintain throughput. Concurrently, the CSS module coordinates CWND growth during the SS, preventing abrupt increases. Implementation on MININET shows that CC-OLIA not only maintains fair performance but also enhances transmission efficiency across diverse network conditions.