  As the communication network is in transition towards a commercial one
controlled by service providers (SP), the present paper considers a pricing
game in a communication market covered by several wireless access points
sharing the same spectrum and analyzes two business models: monopoly (APs
controlled by one SP) and oligopoly (APs controlled by different SPs). We use a
Stackelberg game to model the problem: SPs are the leader(s) and end users are
the followers. We prove, under certain conditions, the existence and uniqueness
of Nash equilibrium for both models and derive their expressions. In order to
compare the impact of different business models on social welfare and SPs'
profits, we define two metrics: PoCS (price of competition on social welfare)
and PoCP (price of competition on profits). For symmetric cross-AP
interferences, the tight lower bound of PoCS is 3/4, and that of PoCP is 1.
