The operation of TCP over Aeronautical Networks

Abstract

The expected evolution of aircraft traffic in the next decades and the foreseen lack of communication resources in the European airspace produce an increased need for efficient aeronautical data communications. Several research projects aim to pave the way to all-IP networks for aeronautical communication (ATN/IPS). The Internet Protocol suit plays an important role in this endeavour not only because of the intended paradigm shift from operational ATC-voice to ATM-data communication, but also due to expected cost reductions offered by open standards and commercial of the shelf products. Within this paper the mode of operation and the performance of TCP in the aeronautical context are investigated. These investigations are based on typically aeronautical link characteristics (terrestrial or satellite). In particular the following issues are addressed: - How should TCP be used for aeronautical applications? Initiate and hold connections at the beginning of each flight or should connections be established for each data transfer independently (causing lots of overhead)? - How does TCP behave when a low-bandwidth link is under-fed, that is, when the offered traffic rate per connection is much less that link rate - What are the effects of a very large number of concurrent connections each with very thin traffic? - How does TCP behave when operating near congestion of the network as a whole? In particular, when random peaks in the traffic actually overload the link capacity temporarily