Improving end-to-end performance of TCP over mobile internetworks

Reliable transport protocols such as TCP use end-to-end flow, congestion and error control mechanisms to provide reliable delivery over an internetwork. However, the end-to-end performance of a TCP connection can suffer significant degradation in the presence of a wireless link. We are exploring alternatives for optimizing end-to-end performance of TCP connections across an internetwork consisting of both fixed and mobile networks. The central idea in our approach is to transparently split an end-to-end connection into two separate connections; one over the wireless link and other over the wired path. The connection over the wireless link may either use regular TCP or a specialized transport protocol optimized for better performance over a wireless link. Our approach does not require any changes to the existing protocol software on stationary hosts. Results of a systematic performance evaluation using both our approach and regular TCP show that our approach yields significant performance improvements.