  In this note, we study the asymptotical frontier behavior of a branching
reflected Brownian motion. There is essentially no difference in maximal
displacement between a branching Brownian motion and its reflected counterpart.
We provide two proofs of this fact, one via a soft argument on the dependance
of two-sided extremal particles in a branching Brownian motion and the other
based on direct computations as in Roberts. The asymptotics of minimal
displacement is also given.
