Dynamic PSS and commercial networks spectrum sharing in the time domain

It is widely recognized that the possibility for Public Safety and Security operators of using a wide range of data-centric services improves their coordination and responses to emergency. Therefore, there is great consensus in the evolution of existing PSS mobile communication systems towards broadband, with the exploitation of Long Term Evolution technology, commonly used in commercial networks. Having a unique technology allows synergies between commercial and PSS worlds; in particular, we are interested in an efficient spectrum sharing between the two networks. Indeed, a portion of spectrum dedicated to PSS, large enough to satisfy emergency situations, may result unused most of the time, with a consequent waste of precious resources. We propose a spectrum sharing policy based on dynamic subframe allocation of time subframes. Differently from previous approaches, we consider some resource portions exclusively dedicated to one of the two networks, and other portions simultaneously accessed. Therefore, the goal of the proposed scheme is to find suitable resource partitioning and users allocation. Users are allocated depending on the level of received interference, with the aim of a fair behavior in different portions of the frame. Moreover, the algorithm takes into account different priorities that can be given to the two networks systems depending on the operative scenario. Effectiveness and accuracyof the proposed scheme are proven by a comparison with other benchmark methods and with the optimal solution of the resource partitioning problem, in terms of unsatisfied data rate requests.