• Rita Mahajan
• Jaspreet Kaur
• Deepak Bagai

A wireless sensor network consists of wireless sensor nodes with in-build communication capabilities, but with limited battery. Wireless sensor networks (WSNs) are networks of randomly distributed autonomous devices that can sense the physical conditions of any system cooperatively and then produces electrical output which can be further processed for any desired operation. But due to the swift proliferation of the various wireless communication techniques the frequency bands used for wireless communication almost depleted. In order to cope up with this scarcity of frequency spectrum, cognitive radio comes to the rescue. Cognitive radio is a solution to the limited frequency spectrum which allows the secondary (unlicensed) users to utilize the frequency spectrum of the primary (licensed) users, when they are not using their licensed spectrum. A cognitive wireless sensor network is a most recent and promising technique for utilizing our useful and limited spectrum very intelligently to increase the spectral efficiency.

CRWSN: Cognitive radio wireless sensor networks, PU: Primary user, SU: Secondary user, Licensed Spectrum, Clustering

"A REVIEW ON COGNITIVE RADIO WIRELESS SENSOR NETWORKS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 5, page no.486-489, May-2019, Available :http://www.jetir.org/papers/JETIR1905Q68.pdf

"A REVIEW ON COGNITIVE RADIO WIRELESS SENSOR NETWORKS", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 5, page no. pp486-489, May-2019, Available at : http://www.jetir.org/papers/JETIR1905Q68.pdf