From an Enhanced TCP to a Multi‐Stream TCP for GEO Satellite Return Links

To address the severe performance degradation of TCP caused by high latency, time‐varying link capacity, and high error rates in the return links of geostationary Earth orbit (GEO) satellite networks, this paper proposes two improvement schemes: TCP‐GEO and Multi‐stream TCP. TCP‐GEO designs an adaptive startup mechanism and adjusts congestion thresholds and window growth strategies dynamically by incorporating the terminal‐side information—the allocated bandwidth and the number of concurrent TCP flows. To further address multi‐flow contention for the terminal's bottleneck bandwidth, Multi‐stream TCP adopts a centralized coordination architecture entity, which constructs an initial window allocation model sensitive to these two terminal‐side information, and introduces a joint link state discrimination mechanism using cross‐flow correlation to precisely distinguish packet loss caused by terrestrial network congestion and by channel fading, and implements a hierarchical bandwidth allocation policy based on service priority to support differentiated quality of service (QoS). Simulation experiments based on the Satellite Network Simulator 3 demonstrate that TCP‐GEO significantly improves bandwidth utilization and fairness. Multi‐stream TCP further betters these performance metrics through centralized multi‐stream coordination and guarantees transmission rates for high‐priority services, making it most suitable for complex environmental scenarios with the bandwidth bottleneck at the terminal.