Radio Access and Spectrum A white paper on spectrum sharing

What is spectrum sharing ? The traditional way of handling spectrum for cellular wireless wide area networks is illustrated in Figure 1-a, where two operators own certain parts of the spectrum which is again subdivided into three smaller frequency bands each assigned to one Radio Access Technology (RAT). A trend of more flexible use of spectrum is supported by novel developments in radio technology. The first step to flexible radio spectrum usage for a single operator is intra-operator spectrum sharing which includes the dynamic allocation of RATs within the spectrum blocks of one operator as well as the movement of users between bands (illustrated in Figure 1-b). In a number of European countries the adaptive assignment of RATs to licensed spectrum is allowed by the regulatory bodies [1] enabling the flexible application of Software Defined Radio (SDR) technology.