[Cognitive radio (CR)] Spectrum sensing and multi-band RF [Intelligent antenna (IA)] Multiple- or cooperative-antenna arrays [Point] 
Key cost
P r i n c i p a l g o a l
I n t e r f e r e n c e p r o c e s s i n g
K e y c o s t
C h a l l e n g i n g a l g o r i t h m
A p p l i e d t e c h n i q u e s
B a s e m e n t a p p r o a c h
C o m p e t i t i v e t e c h n o l o g y
S u m m a r y