Cross‐layer enhancement of TCP split‐connections over satellites links

Abstract

Satellites have played an important role in global telecommunications. However, transmission control protocol (TCP) suffers performance degradations over satellite links due to the long propagation delay and high bit-error rate. Among methods proposed to alleviate the impact of satellite link characteristics on TCP performance, split TCP connections separated by performance enhancement proxies (PEPs) have been proven attractive because they can keep TCP configurations in the end systems unchanged. While many protocols applied over satellite links between PEPs can effectively mitigate the effect of high loss rates, the long latency still limits the effectiveness of congestion control in these protocols. To minimize the effect of congestion we propose to take advantage of active queue management at the medium access control layer to provide immediate cross-layer feedback to the TCP segment over satellite. This approach also achieves proper differentiation between packet losses due to channel errors and congestion. Simulation results show that our novel mechanism can give substantial improvements in TCP performance over satellite networks, compared to the best performing version of TCP with or without PEPs.

Cross‐layer protocol optimization for satellite communications networks: a survey

“…weather conditions). In the considered Ka band (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30), atmospheric events have a significant impact on the level of the signal. The effect of the physical layer, where fade countermeasures are applied to contrast fading attenuation, is taken into account as a reduction in the net available bandwidth.…”

“…Another interesting study on the adoption of PEP is performed in Reference [20] that proposes a novel cross-layer congestion control method, called CSACK, for TCP SACK split-connections applied to a satellite link between two PEPs. The key feature of CSACK is local congestion notification from the MAC layer to the TCP layer in the PEP, based on the current MAC buffer occupancy managed by the RED algorithm.…”

Performance Evaluation of PEP Based on Cross-Layer in Satellite Communication System

“…같이 위성 단말(Satellite Terminal), 게이트웨이 Peng의 연구에서는 TCP와 링크계층간의 정보 교환을 통하여 대기열의 오버플로우를 방지하는 TCP 연결 분할 방식을 제안했다 [13] . Luglio와 Alins의 연구에서 는 TCP의 전송 속도를 하위 계층의 버퍼 크기를 고려 하여 조절하는 기법이 제안되었다 [14,15] .…”

An enhanced TCP congestion avoidance scheme and its performance evaluation in high speed satellite networks

“…The total link capacity is configured as 100 Mbps. The same as in [8], the nominal BER values of the contemporary satellite link have been configured in the range of 10 -5 -10 -8 for given simulation experiments, but these values could be degraded to 10 -4 or worse. The throughput illustrated in our simulation results is the saturation throughput, which is a fundamental performance parameter, defined as the limit reached by the system throughput as the offered load increases, and represents the maximum load that the system can carry in stable conditions.…”

“…On the other hand, protocols considering high BERs have also been proposed. For instance, the Cross-layer Selective ACKnowledgement (CSACK) protocol [8] can improve the throughput performance in satellite networks with high BER, but this proxy-based solution may bring a few robustness and security problems. The TCP-Peach protocol [9] introduced two algorithms, namely sudden start and rapid recovery, in addition to the traditional ones like congestion avoidance and fast retransmission.…”