Boosting TCP with Cross-Layer Information Awareness in Wireless Networks
Mouhcine Guennoun
Journal of Information Security Research, Vol. 1, No. 1, 2011.
DOI: 
Link: http://www.dline.info/jism/fulltext/v1n1/5.pdf
Abstract:
It has been demonstrated through simulation and experimental studies that TCP protocol suffers from a significant drop of performance when communicating over wireless networks. In general, packets can be lost for three main reasons: 1) Congestion 2) Link failure due to node mobility, and 3) Losses due to transmission errors. However, TCP doesnâ€™t distinguish between these three types of packet losses. It considers any packet loss as a sign of network congestion; and therefore triggers its exponential back off as a mean to control congestion. In this paper, we study the impact of providing TCP with explicit information extracted from the physical, link and network layers to make it possible to identify the cause of the packet loss. There are three information of interest to this study: maximum probability to drop a packet, signal strength of the wireless node, and explicit handover notification when the mobile node transits to a new access point. We show in the experimental section that by providing TCP sender with only the information regarding the queues states, the performance can be improved by 500% over a lossy wireless link (with 60% error rate).