Network Theory: Connectivity and Capacity

Our portion of this work has been supported by the National Science Foundation under Grants No. ECS-0300130 and CCF-0430892.

As ubiquitous wireless networks become a reality, it is imperative for physical layer researchers to consider end-to-end network performance while prescribing the physical layer, and for network layer researchers to exploit contemporary physical layer capabilities to optimize network performance. We have worked with UMass networking researcher Don Towsley in this area. In [Liu/Goeckel/Towsley, GlobeCom 2002], we set the rate of an adaptive physical layer to optimize end-to-end performance of a TCP session running over the link. More recently, we have considered: (1) how physical layer advances, particularly cooperation among nodes, can change network level behavior [Song/Goeckel/Towsley, InfoCom 2006], (2) how network layer algorithms can exploit contemporary physical layer degrees of freedom [Vasudevan/Zhang/Goeckel/Towsley, InfoCom 2006], and (3) limits of the improvement in scaling performance provided by network coding in large ad hoc networks [Liu/Goeckel/Towsley, InfoCom 2007]. The latter work is of particular interest, demonstrating that network coding with a standard point-to-point physical layer will not be able to significantly improve the pessimistic scaling results of Gupta/Kumar.

  • B. Liu, D. Goeckel, and D. Towsley, "TCP-Cognizant Adaptive Forward Error Correction in Wireless Networks," (PDF file), Proceedings of the IEEE Global Telecommunications Conference (GlobeCom) , November 2002.

  • S. Vasudevan, C. Zhang, D. Goeckel, and D. Towsley, "Optimal Power Allocation in Wireless Networks with Transmitter-Receiver Power Tradeoffs," (PDF file), Proceedings of IEEE InfoCom 2006 , April 2006.

  • S. Song, D. Goeckel, and D. Towsley, "Collaboration Improves the Connectivity of Wireless Networks," (PDF file), Proceedings of IEEE InfoCom 2006 , April 2006.

  • J. Liu, D. Goeckel, and D. Towsley, "The Throughput Order of Ad Hoc Networks Employing Network Coding and Broadcasting," (PDF file) Proceedings of the 2006 Military Communications Conference (MilCom) (invited), October 2006.

  • J. Liu, D. Goeckel, and D. Towsley, "Bounds on the Gain of Network Coding and Broadcasting in Wireless Networks," (PDF file), to appear at IEEE InfoCom 2007.