Next-generation public safety communication (PSC) systems must deliver high-capacity wireless services to public safety personnel and users in disaster-affected areas, with little reliance on infrastructure. Remarkably, modern-day PSC systems have yet to catch up with the past decade's wireless revolution, as they still rely on technologies of yesteryears that fall short on delivering high-speed wireless access. Indeed, coping with the foreseen stringent service requirements in future PSC systems mandates major innovations that can increase spectral efficiency. This, in turn, requires tackling multidisciplinary challenges: 1) developing incentive mechanisms for government agencies, providers, and users to share their precious spectrum resources; 2) dynamically managing interdependent spectrum markets; and 3) efficiently modeling and operating sustainable communication protocols that can function with little infrastructure support. This project brings together researchers in wireless communications and networking, game theory, mathematics, and public safety administration to address these challenges and boost the efficiency of PSC by introducing a novel framework that provides the necessary analytical tools for modeling, designing, analyzing, and operating large-scale spectrum sharing in disaster and emergency situations. The overarching scientific merit of this research is to initiate the much-needed leap towards a more open, highly participatory, and pervasive sharing of the wireless spectrum for PSC. This project offers an array of spectrum sharing innovations: 1) new economic approaches and PSC mechanisms that provide incentives for government agencies, providers, and end-users, to effectively subsidize the scarce radio spectrum and facilitate novel public safety and spectrum allocation policies; 2) a foundational framework that tightly integrates tools from game theory and auction theory for enabling a dynamic operation of co-existing spectrum sharing markets with multi-hop capabilities; 3) novel realistic models for characterizing wireless channels, traffic, topology, user behavior, and mobility in PSC; and 4) effective and accelerated transition of theoretical results to practice via a new PSC testbed for extensive validation and close collaboration with several major industry partners and local public safety agencies. In a nutshell, the project provides a new generation of PSC systems and protocols that expedite the response to disasters, save lives, and reduce economic costs.