Date Added: Sep 2009
The spectrum scarcity problem emerged in recent years, due to unbalanced utilization of RF (Radio Frequency) bands in the current state of wireless spectrum allocations. Different from cognitive radio approaches which are opportunistic and non-collaborative in general, spectrum access scheduling proactively structures and interleaves the channel access pattern of heterogeneous wireless systems, using collaborative designs by implementing a crucial architectural component - the base stations on Software Defined Radios (SDRs). It discusses system design choices for spectrum sharing from multiple perspectives, then presents the mechanisms for spectrum sharing and coexistence of GPRS+WiMAX and GPRS+WiFi as use cases, respectively. Simulations were carried out to prove that spectrum access scheduling is an alternative, feasible and promising approach to the spectrum scarcity problem.