ALCS: An Adaptive Latency Compensation Scheduler for Multipath TCP in Satellite-Terrestrial Integrated Networks

TL;DR

This paper tackles the challenge of efficient data transmission over Satellite-Terrestrial Integrated Networks (STIN) using Multipath TCP (MPTCP). It introduces Adaptive Latency Compensation Scheduler (ALCS), which combines robust latency estimation across satellite and terrestrial paths with adaptive compensation and proactive handover management to mitigate handover disruptions. Implemented in the MPTCP Linux kernel and evaluated on a Docker-based STIN testbed, ALCS demonstrates throughput gains of 9.8% to 44.0% and substantially reduced retransmissions compared to conventional schedulers like minRTT, RR, BLEST, and ECF. The work offers a practical STIN-specific scheduling framework that leverages satellite trajectory information and path metrics to improve reliability and efficiency in dynamic, heterogeneous networks.

Abstract

The Satellite-Terrestrial Integrated Network (STIN) enhances end-to-end transmission by simultaneously utilizing terrestrial and satellite networks, offering significant benefits in scenarios like emergency response and cross-continental communication. Low Earth Orbit (LEO) satellite networks offer reduced Round Trip Time (RTT) for long-distance data transmission and serve as a crucial backup during terrestrial network failures. Meanwhile, terrestrial networks are characterized by ample bandwidth resources and generally more stable link conditions. Therefore, integrating Multipath TCP (MPTCP) into STIN is vital for optimizing resource utilization and ensuring efficient data transfer by exploiting the complementary strengths of both networks. However, the inherent challenges of STIN, such as heterogeneity, instability, and handovers, pose difficulties for traditional multipath schedulers, which are typically designed for terrestrial networks. We propose a novel multipath data scheduling approach for STIN, Adaptive Latency Compensation Scheduler (ALCS), to address these issues. ALCS refines transmission latency estimates by incorporating RTT, congestion window size, inflight and queuing packets, and satellite trajectory information. It further employs adaptive mechanisms for latency compensation and proactive handover management. It further employs adaptive mechanisms for latency compensation and proactive handover management. Implemented in the MPTCP Linux Kernel and evaluated in a simulated STIN testbed, ALCS outperforms existing multipath schedulers, delivering faster data transmission and achieving throughput gains of 9.8% to 44.0% compared to benchmark algorithms.

Figures (9)

• Figure 1: MPTCP data transmission diagram for STIN.
• Figure 2: Latency dynamics in a simulated STIN environment.
• Figure 3: CDF of the difference between the maximum and minimum RTTs of the satellite path.
• Figure 4: Flowchart diagram of the proposed ALCS.
• Figure 5: Topology of the simulated STIN.