ABSTRACT
Spectrum is a key to mobile wireless communications. Spectrum management is an important challenge for the evolution of 5G communications. A good amount of vacant spectrum is available at mm-waves which could be utiliszed for 5G communications services. This chapter discusses the concept of spectrum sharing and spectrum trading. The success of 5G network is based on the unconstrained availability of spectrum. The conventional method for allocating spectrum is known as “Command and Control Method”. Spectrum sharing has basically three dimensions: frequency, time and location. The Collective Use of Spectrum allows spectrum to be used by more than one user simultaneously without requiring a license. Evolution of software defined radio and cognitive radio are the two major milestones in the mobile communications. Dynamic sharing of spectrum improves the spectrum efficiency and the mentioned technologies play a vital role in this aspect. Spectrum trading is a case of spectrum sharing with the involvement of commercial activities.
