Research Article
Disruption-Tolerant Link-level Mechanisms for Extreme Wireless Network Environments
@INPROCEEDINGS{10.1109/COMSWA.2007.382567, author={Vijaynarayanan Subramanian and K.K. Ramakrishnan and Shivkumar Kalyanaraman}, title={Disruption-Tolerant Link-level Mechanisms for Extreme Wireless Network Environments}, proceedings={2nd International IEEE Conference on Communication System Software and Middleware}, publisher={IEEE}, proceedings_a={COMSWARE}, year={2007}, month={7}, keywords={Automatic repeat request Delay Economic indicators Error analysis Forward error correction Interference Performance loss Protocols TCPIP Wireless networks}, doi={10.1109/COMSWA.2007.382567} }- Vijaynarayanan Subramanian
K.K. Ramakrishnan
Shivkumar Kalyanaraman
Year: 2007
Disruption-Tolerant Link-level Mechanisms for Extreme Wireless Network Environments
COMSWARE
IEEE
DOI: 10.1109/COMSWA.2007.382567
Abstract
Wireless links pose significant challenges in terms of achievable goodput and residual loss-rate. Our recent enhancements, called LT-TCP make TCP loss-tolerant in heavy/bursty erasure environments. Link-level protocols mitigate these problems by using a combination of FEC and ARQ but are insufficient when the channel experiences disruptions. When the underlying source of loss is interference (e.g., 802.11 environments), MAC-level mechanisms misinterpret interference as noise leading to poor scheduling (e.g., capture effects) and limit the benefit of transport layer mitigation efforts. We propose enhancements to link-level protocols that enable survival during disruptions. We explore an adaptive link-level strategy to export a small residual loss rate and bounded latency under high loss/ disruption conditions. We evaluate the proposed link-level enhancements, showing that the combination with LT-TCP helps achieve significant end-to-end performance gains. We also demonstrate the trade-off between reduced link layer residual loss (by increasing ARQ persistence) and transport layer timeouts.
