  As cellular networks are turning into a platform for ubiquitous data access,
cellular operators are facing a severe data capacity crisis due to the
exponential growth of traffic generated by mobile users. In this work, we
investigate the benefits of sharing infrastructure and spectrum among two
cellular operators. Specifically, we provide a multi-cell analytical model
using stochastic geometry to identify the performance gain under different
sharing strategies, which gives tractable and accurate results. To validate the
performance using a realistic setting, we conduct extensive simulations for a
multi-cell OFDMA system using real base station locations. Both analytical and
simulation results show that even a simple cooperation strategy between two
similar operators, where they share spectrum and base stations, roughly
quadruples capacity as compared to the capacity of a single operator. This is
equivalent to doubling the capacity per customer, providing a strong incentive
for operators to cooperate, if not actually merge.
