上洋充通大学 Cognitive Radio Networks (CRN) SHANGHAI JIAO TONG UNIVERSITY ▣Spectrum Mobility >High-priority PUs can reclaim their licensed channels at any time. >SUs must cease their transmission on the licensed channels. >Spectrum availability is dynamic(or mobile)to secondary users. Time 1 Time 2 idle idle SU PU PU 55 Cognitive Radio Networks (CRN) ❑ Spectrum Mobility ➢ High-priority PUs can reclaim their licensed channels at any time. ➢ SUs must cease their transmission on the licensed channels. ➢ Spectrum availability is dynamic (or mobile) to secondary users. SU PU 1 2 3 idle Time 2 SU PU 1 2 3 Time 1 idle