4th International IEEE Conference on Broadband Communications, Networks, Systems

Research Article

Wireless Traffic: The Failure of CBR Modeling

  • @INPROCEEDINGS{10.1109/BROADNETS.2007.4550497,
        author={Stefan Karpinski and Elizabeth M. M.  Belding and Kevin C.  Almeroth},
        title={Wireless Traffic: The Failure of CBR Modeling},
        proceedings={4th International IEEE Conference on Broadband Communications, Networks, Systems},
        keywords={Computer science  Local area networks  Measurement  Routing protocols  Space exploration  Telecommunication traffic  Testing  Traffic control  Wireless LAN  Wireless application protocol},
  • Stefan Karpinski
    Elizabeth M. M. Belding
    Kevin C. Almeroth
    Year: 2010
    Wireless Traffic: The Failure of CBR Modeling
    DOI: 10.1109/BROADNETS.2007.4550497
Stefan Karpinski1,*, Elizabeth M. M. Belding1,*, Kevin C. Almeroth1,*
  • 1: Department of Computer Science University of California, Santa Barbara
*Contact email: sgk@cs.ucsb.edu, ebelding@cs.ucsb.edu, almeroth@cs.ucsb.edu


When new wireless technologies are deployed and subjected to real usage patterns, unforeseen performance problems inevitably seem to arise, to be fixed only in later generations. Why do these performance issues fail to appear in experimental settings before the technology is deployed? We believe that one of the major reasons behind the discrepancies found between experimental performance evaluations and real-world experience lies in the unrealistic workload patterns typically used in experiments. One of the significant contributions of this work is to rigorously demonstrate that common synthetic traffic models for wireless local-area networks induce drastically distorted performance metrics at every layer of the protocol stack. In order to show this, we present a testable definition of “sufficient realism” for traffic models, and develop the theoretical methodology necessary to interpret experimental results using this definition. Finally, we show by example that this distortion can completely invert the relative performance of protocols. The greater overall contribution of this paper, however, is the complete collection of ideas, techniques and analytical tools that will allow the development of more realistic synthetic traffic models in the future.