Abstract: The rapid development of modern wireless communication technology requires more and more spectrum which renders the transaction from static spectrum allocation to dynamic spectrum allocation. Aimed at the question that multiple networks access an coordinated spectrum access spectrum(CSAB) through a central spectrum broker, an improved dynamic spectrum allocation mechanism was proposed based on real-time spectrum demand and offer mapping (RT-DOM). As contrast with general sequential dynamic spectrum allocation(S-DSA) mechanism, the RT-DOM focuses on the spectrum requirement change between two consecutive dynamic periods, and maps the released spectrum (spectrum offer) and the new spectrum demand,in order to make less the spectrum handover than S-DSA And the simirlation results show that the spectrum handover reduces at least 75% while allocation gain reduces very little.

Key words: Dynamic spectrum allocation, Real-time spectrum demand and offer mapping, Allocation gain, Spectrum handover efficiency