This paper discusses several schemes designed to improve the performance of TCP over wireless links that suffer from significant packet losses due to bit errors and handoffs. Currently, TCP control mechanisms are insufficient for such links because they assume that all losses are congestion-related and thus can unnecessarily reduce end-to-end throughput. The authors classify these schemes as end-to-end protocols, link-layer protocols and split-connection protocols. Using end-to-end throughput over wired and wireless hops as a performance metric, a TCP-aware link-layer protocol with selective acknowledgments proved to provide the highest throughput. End-to-end schemes also proved to be effective, do not require additional support from intermediate nodes and can improve throughput dramatically when combined with an ELN mechanism.
Reading this paper provided a good insight into a variety of methods for effective TCP-based transmission over lossy wireless links without having to learn the details of these methods. The focus was on the bottom line: optimizing end-to-end throughput. However, the evaluation seemed rather simplistic as the protocols were implemented under a basic range of bit-error rates. This provided valuable results but simulation and analysis under real network conditions may reveal new information in this field. Overall, this was a very informative paper and built somewhat on the previous one.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment