What is Global System for Mobile Communication, GSM

The growing demands of radio spectrum urgently require more efficient and effective spectrum exploitation and management technologies. Cognitive radio technology and its networking not only explores the potential white spectrum resources temporally and geographically, but also enables an extensive efficient utilization and optimization of the current allocated spectrum resources. Therefore, rapid progress has been made in the research on cognitive radio and its networking technologies to facilitate more flexibilities in spectrum utilization and management. In this chapter, the authors first summarize the current various advanced and flexible spectrum management schemes, including spectrum trading, leasing, pricing, and harvesting, and analyze their advantages and disadvantages. Then, they take the viewpoints of both the spectrum marketing perspective and spectrum technical perspective, and they propose the centralized and distributed dynamic spectrum sharing schemes, respectively. In particular, the authors introduce many novel advanced spectrum sharing scheme and summarize the open and possible research problems.