2nd International IEEE Conference on Communication System Software and Middleware

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
Vijaynarayanan Subramanian1, K.K. Ramakrishnan2,*, Shivkumar Kalyanaraman1,*
  • 1: ECSE Dept, RPI
  • 2: AT&T Labs Research
*Contact email: kkrama@research.att.com, kalyas@rpi.edu

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.