In this talk, we present some recent results on minimizing the
end-to-end buffer usage (which corresponds to the end-to-end delay along
a flow path) over a multihop wireless network with general topology and
with fixed, loop-free routes.  We present a class of (backpressure-like)
scheduling algorithms called $\alpha\beta$-algorithms, whose parameters
can be chosen such that the decay rate function for end-to-end buffer
overflow is shown to be arbitrarily close to optimal in the large-buffer
regime. Further, we develop variants that have the same asymptotic
optimality property, and also provide good performance in the
small-buffer regime.