  We consider a simple two-player game involving a large incumbent and small
entrant into a cellular wireless access provider marketplace. The entrant's
customers must pay roaming charges. We assume that the roaming charges are
regulated, because if they are dictated by the incumbent then they could be set
so high so as to be a barrier to entry in the marketplace. The game is studied
at its Nash equilibrium. A roaming charge is identified that is arguably fair
in the sense that revenues for the access providers are proportionate to their
infrastructure costs.
