Asymptotic behavior of the stationary distribution in a finite QBD process with zero mean drift

We consider a finite QBD process with m levels. Assuming that the mean drift is 0, we obtain an asymptotic behavior @p"m^(^m^)~(1/m)c as m->~ in the stationary distribution (@p"0^(^m^),...,@p"m^(^m^)), by finding an explicit expression for vector c. This solves the problem that was conjectured by Miyazawa et al. [Asymptotic behaviors of the loss probability for a finite buffer queue with QBD structure, StochasticModels 23 (2007) 79-95].