A multi-path transport protocol to exploit network diversity in airborne networks

Airborne links are playing an increasingly important role in defense and military scenarios. This makes it important to investigate the performance of existing transport protocols over such links. Airborne links experience high variation in quality due to mobility, weather and other effects such as blockage. This translates to high loss rate environments for which current protocols are not designed. Consequently, the standard protocols fail to deliver high data rates. In prior work, we presented loss-tolerant TCP (LT-TCP) which is designed for such airborne links. We have now extended this protocol to take advantage of the availability of multiple paths in the network. We call this multi-path loss-tolerant TCP (MPLOT). In this paper, we investigate the statistical characteristics of airborne links using data gathered from actual experiments and develop mathematical models for such links. We then proceed to use these models to test MPLOT in the ns-2 network simulator. Our results show that while standard protocols such as TCP-SACK are unable to perform well, MPLOT can deliver higher goodput and lower latency than conventional transport protocols like TCP-SACK. MPLOT can leverage path diversity in the network to deliver even higher goodput as number of paths increase even while the total bandwidth remains fixed.