Protocol behavior: more effort, more gains?
Lefteris Mamatas, Vassilis Tsaoussidis · 2005
We investigate the behavior of TCP(/spl alpha/,/spl beta/) protocols in the presence of wireless networks. We seek an answer to strategic issues of maximizing energy and bandwidth exploitation, without damaging the dynamics of multiple-flow equilibrium. Our perspective is novel indeed: What is the return of the effort that a protocol expends? Can we achieve more gains with less effort? We study first the design assumptions of TCP(/spl alpha/,/spl beta/) protocols and discuss the impact of equation-based modulation of /spl alpha/ and /spl beta/ on protocol efficiency. We introduce two new metrics to capture protocol behavior: The "extra energy expenditure" and the "unexploited available resource index". We confirm, by simulation experiments, that, in general, smoothness and responsiveness constitute a tradeoff; however, we show that this tradeoff does not graft its dynamics into a conservative/aggressive behavior, as is traditionally believed. We uncover patterns of unjustified tactics; our results suggest that an adaptive congestion control algorithm is needed to integrate the dynamics of heterogeneous networks into protocol behavior.