Evaluation of TCP and Internet traffic via low Earth orbit satellites

The prospect of the Internet as the fastest growing satellite communication application coupled with satellite-based multimedia networks has generated a high level of interest in the performance of TCP over satellite systems. This article presents the network architecture for supporting services based on TCP/IP over satellite. It discusses the key factors that influence TCP performance over satellite links, and compares the benefits and disadvantages of low Earth orbit and geostationary Earth orbit satellite. The article also discusses the feasibility of using LEO satellites to support and expand the Internet. It presents studies of the TCP behavior over a GEO satellite system and LEO satellite constellation based on computer simulations, where two typical Internet applications are taken into consideration: FTP file transfer and Web browsing. The results show that TCP performs much better over the LEO satellite constellation than over the GEO system; even the standard TCP over LEO is better than enhanced TCP over GEO.