Enhancing TCP based communications in mobile satellite scenarios: TCP PEPs issues and solutions

Networking has experienced tremendous changes. Once dedicated to one single type of services, technologies are now offering integrated services: we want to have access to any services anywhere. One challenge is the mobility, with 3G terrestrial offers beginning to be successful. In such a context, satellite systems appear as a real opportunity since they may fill the gap between dense connected areas (city) and low populated areas. Nevertheless, Internet-like communications over satellite segments needs TCP Performance Enhancing Proxies (PEPs) to alter classical TCP on satellite part for a better behaviour. As a drawback, PEPs often induce connection splitting and thus hinder mobility. This paper tackles this issue. After a brief introduction on existing satellite mobile systems and on PEPs mechanisms, we focus on mobility scenarios and propose some architecture elements. A detailed case is settled to illustrate context transfer issues.