Experimental Performance Evaluation of TCP over an Integrated Satellite-Terrestrial Network Environment

Abstract

In this paper, we present the experimental measurement and evaluation of Transmission Control Protocol (TCP) performance over Internet Protocol (IP) using a real, heterogeneous network environment, incorporating at least one leg of satellite and land mobile link that, together, make an Integrated Satellite-Terrestrial Network (ISTN) testbed for our investigation and performance analysis. Originally, the TCP algorithm was developed for short latency and low link error network environments and has become a de-facto standard protocol for the reliable delivery of IP traffic over the Internet, which, in reality, is a heterogeneous network environment nowadays. Using the real latency figures measured with our testbed systems, we numerically analyse the performance of a standard TCP scheme and compare it with the newly developed TCP Hybla algorithm that claims to address performance degradation due to long round-trip-time (RTT) and high wireless link error channels such as Geostationary Satellite Links. The overall performance was compared with the achievable throughput of each of the two TCP algorithms and available bandwidth of the real testbed system. TCP Hybla performed better even with changing real values of RTT obtained from a real hybrid ISTN environment with a Geostationary Satellite link as the testbed.